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Objective　To investigate the clinical features of patients with acute-on-chronic liver failure （ACLF） and bacterial infection and early warning indicators associated with multidrug-resistant infections. Methods　A retrospective analysis was performed for 130 patients with ACLF and bacterial infection who attended The Second Affiliated Hospital of Air Force Medical University from January 1, 2010 to December 31, 2021, and according to the drug susceptibility results, the patients were divided into multidrug-resistant （MDR） bacterial infection group with 80 patients and non-MDR bacterial infection group with 50 patients. General information and laboratory examination results were compared between the two groups to screen for the early warning indicators associated with MDR bacterial infection. The Student’s t-test was used for comparison of normally distributed continuous data with homogeneity of variance between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data or continuous data with heterogeneity of variance between two groups； the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. The binary logistic regression analysis and the receiver operating characteristic （ROC） curve were used to assess the predictive value of early warning indicators. Results　Among the 130 patients with ACLF and bacterial infection， sputum （27.7%） was the most common specimen for detection， followed by blood（ 24.6%), urine（ 18.5%), and ascites（ 17.7%). Bacterial infections were dominated by Gram-negative bacteria（ 58.5%). Of all bacteria， Escherichia coli （18.5%), Klebsiella pneumoniae （14.6%), and Enterococcus faecium （13.8%） were the most common pathogens. Gram-positive bacteria had a high resistance rate to the antibacterial drugs such as erythromycin （72.2%), penicillin （57.4%), ampicillin （55.6%), and ciprofloxacin （53.7%), while Gram-negative bacteria had a high resistance rate to the antibacterial drugs such as ampicillin （73.3%), cefazolin （50.0%), and cefepime （47.4%). The patients with ACLF and bacterial infection had a relatively high rate of MDR bacterial infection （61.5%). Comparison of clinical data between the two groups showed that compared with the patients with non-MDR bacterial infection， the patients with MDR bacterial infection had significantly higher levels of alanine aminotransferase （Z=2.089， P=0.037), aspartate aminotransferase （Z=2.063， P=0.039), white blood cell count （Z=2.207， P=0.027), and monocyte count （Z=4.413， P<0.001). The binary logistic regression analysis showed that monocyte count was an independent risk factor for MDR bacterial infection （odds ratio=7.120， 95% confidence interval ［CI］： 2.478 — 20.456，P<0. 001） and had an area under the ROC curve of 0.686 （95%CI： 0.597 — 0.776） in predicting ACLF with MDR bacterial infection（P<0. 001), with the optimal cut-off value of 0.50×109/L， a sensitivity of 0.725， and a specificity of 0.400. Conclusion　ACLF combined with bacterial infections is mainly caused by Gram-negative bacteria， with the common pathogens of Escherichia coli and Klebsiella pneumoniae and a relatively high MDR rate in clinical practice. An increase in monocyte count can be used as an early warning indicator to distinguish MDR bacterial infection from non-MDR bacterial infection. [ABSTRACT FROM AUTHOR]

Objective To investigate the mechanism of luteolin's (Lut) reversal effect on multidrug resistance of chronic myeloid leukemia K562/ADR cells. Methods CCK-8 assay was used to detect drug resistance in K562 and K562/ADR cells 24 hours after treatment with different doses of adriamycin (ADR). CCK-8 assay was used to assess the cytotoxicity and sensitizing effect of Lut on ADR after K562/ADR cells were treated with Lut alone or in combination with ADR for 24 hours. K562/ADR cells in logarithmic growth phase were separated into three group: 0 µmol/L Lut, 2 µmol/L and 4 µmol/L Lut groups. ADR accumulation in cells was measured using flow cytometry. Nuclear factor erythroid-2-related factor 2 (Nrf2), multidrug resistance associated protein 1 (MRP1), P-glycoprotein (P-gp) and glutathione-S-transferase-PI (GST-pi) mRNA and protein expressions were identified using RT-PCR and Western blot assay. Glutathione (GSH) kit was used to detect intracellular GSH content. Results Compared with K562 cells, K562/ADR cell line was significantly resistant to ADR, and the drug resistance was 53.69 times. K562/ADR cell proliferation was decreased to variable degrees by different doses of Lut when compared to the 0 µmol/L Lut group (P＜0.05). The proliferation inhibition rates of K562/ADR cells treated with 2 and 4 µmol/L Lut were less than 10%, indicating that the concentration of Lut was non-toxic. Compared with the 0 µmol/L Lut group, the 2 µmol/L Lut group and the 4 µmol/L Lut group showed significantly increased ADR growth inhibition rate on K562/ADR and increased accumulation of ADR in cells, improved the reversal resistance fold, and decreased GSH content in cells. MRP1, P-gp, GST-pi and Nrf2 mRNA and protein expression were reduced in cells (P＜ 0.05). The effect of 4 mol/L Lut was greater than that of 2 mol/L Lut. Conclusion Lut may decrease K562/ADR cell proliferation and reverse ADR medication resistance. The mechanism could be connected to the downregulation of Nrf2, MRP1, P-gp and GST-pi expression, which leads to an increase in ADR accumulation in K562/ADR cells. [ABSTRACT FROM AUTHOR]

Objective: To investigate the reversal effect and mechanism of asiatic acid (AA) on multidrug resistance in human adriamycin (ADR) chronic myeloid leukemia K562/ADR cells., Methods: CCK-8 assay was used to detect the resistance of K562 cells and K562/ADR cells to ADR. CCK-8 assay was used to detect the effect of AA on K562/ADR cell viability and adriamycin sensitization. After K562/ADR cells were treated with non-toxic doses of AA(10, 20 μmol/L), the average fluorescence intensity of ADR was detected by flow cytometry. Real-time quantitative PCR was used to detect the expression levels of MRP1, P-gp, β-catenin, C-myc and cyclinD1 mRNA. Western blot was used to detect the expression levels of MRP1, P-gp, β-catenin, C-myc and cyclinD1 proteins. Western blot assay was used to detect the expression levels of MRP1, P-gp, β-catenin, C-myc and cyclinD1 proteins in K562/ADR cells treated with 20 μmol/L AA and Wnt/β-catenin pathway agonist WAY-262611 (5 μmol/L)., Results: The CCK-8 assay showed that the drug resistance of K562/ADR cells was 56.57 times that of K562 cells, showing stable drug resistance, and the difference was statistically significant ( P < 0.05). AA inhibited the proliferative activity of K562/ADR cells in a concentration-dependent manner（ r =0.9666）. Compared with 0 μmol/L AA group, the 10 and 20 μmol/L AA groups could significantly enhance the average fluorescence intensity of intracellular ADR ( P < 0.05), and reverse the cell resistance to ADR ( P < 0.05). The mRNA and protein expressions of MRP1, P-gp, β-catenin, C-myc and cyclinD1 in cells were down-regulated ( P < 0.05). Compared with 20 μmol/L AA group, the expression levels of MRP1, P-gp, β-catenin, C-myc and cyclinD1 protein in 20 μmol/L AA+WAY group were significantly increased ( P < 0.05)., Conclusion: AA inhibits K562/ADR cell proliferation in a concentration-dependent manner and reverse their resistance to ADR, the reversal mechanism may be related to the down-regulation of MRP1 and P-gp expression after inhibiting Wnt/β-catenin signaling pathway.

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Objective: To investigate the mechanism of drug reversing resistance of Agaricus blazei extract FA-2-b-β on T cell acute lymphoblastic leukemia (T-ALL) cell lines., Methods: Cell proliferation was detected by CCK-8 assay; the apoptosis, cell cycle mitochondrial membrane potential, and intracellular rhodamine accumulation were detected by flow cytometry, and apoptosis-related gene and protein expression were detected by qPCR and Western blot; the membrane surface protein MDR1 was observed by immunofluorescence microscopy., Results: Different concentrations of FA-2-b-β significantly inhibited proliferation and induced apoptosis of CCRF-CEM and CEM/C1 ( P <0.05), and CCRF-CEM cell cycle were arrested at S phase, and CEM/C1 cells were arrested at G 0 /G 1 phase. Western blot and qPCR results show that FA-2-b-β inhibited ABCB1、ABCG2、CTNNB、MYC and BCL-2 expression, but upregulated Bax expression. In addition, FA-2-b-β reversed the resistance characteristics of CEM/C1 drug-resistance cells, which decreased mitochondrial membrane potential, and significantly increased the intracellular rhodamine accumulation, and weakening of the expression of the membrane surface protein MDR1. With the Wnt/β-catenin inhibitor (ICG001), the process was further intensified., Conclusion: Agaricus Blazei Extract FA-2-b-β inhibits cell proliferation, promotes apoptosis, regulates the cell cycle, reduces mitochondrial energy supply, and down-regulate MDR1 expression to reverse the resistance of CEM/C1, which all suggest it is through regulating the Wnt signaling pathway in T-ALL.

Objectives: Fluorouracil chemotherapeutic drugs are the classic treatment drugs of gastric cancer. But the problem of drug resistance severely limits their clinical application. This study aims to investigate whether hypoxia microenvironment affects gastric cancer resistance to 5-fluorouracil (5-FU) and discuss the changes of gene and proteins directly related to drug resistance under hypoxia condition., Methods: Gastric cancer cells were treated with 5-FU in hypoxia/normoxic environment, and were divided into a Normoxic+5-FU group and a Hypoxia+5-FU group. The apoptosis assay was conducted by flow cytometry Annexin V/PI double staining. The real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to detect the expression level of hypoxia inducible factor-1α (HIF-1α), multidrug resistance (MDR1) gene, P-glycoprotein (P-gp), and vascular endothelial growth factor (VEGF) which were related to 5-FU drug-resistance. We analyzed the effect of hypoxia on the treatment of gastric cancer with 5-FU., Results: Compared with the Normoxic+5-FU group, the apoptosis of gastric cancer cells treated with 5-FU in the Hypoxia+5-FU group was significantly reduced (P<0.05), and the expression of apoptosis promoter protein caspase 8 was also decreased. Compared with the the Normoxic+5-FU group, HIF-1α mRNA expression in the Hypoxia+5-FU group was significantly increased (P<0.05), and the mRNA and protein expression levels of MDR1, P-gp and VEGF were also significantly increased (all P<0.05). The increased expression of MDR1, P-gp and VEGF had the same trend with the expression of HIF-1α., Conclusions: Hypoxia is a direct influencing factor in gastric cancer resistance to 5-FU chemotherapy. Improvement of the local hypoxia microenvironment of gastric cancer may be a new idea for overcoming the resistance to 5-FU in gastric cancer.

Objective: To investigate the effect of ursane triterpenoids 3β,19α-dihydroxyursu-12-ene-23,28-dicarboxylic acid (Rotundioic acid, RA) on the sensitivity of adriamycin-resistant K562 cells (K562/ADM Cell) anti-tumor drug, and to explore the effect and mechanism of RA on the multidrug resistance of K562/ADM cells., Methods: CCK-8 method was used to detect the effect of RA on the sensitivity of K562 cells and K562/ADM cells to anti-tumor drug. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression level of mRNA and the protein in K562 and K562/ADM cells, and the effect of RA on the expression of MDR1 mRNA and P-gp in K562/ADM cells was also detected; Western blot was used to detect the expression of p-JNK, p-p38 and p-ERK1/2 in K562/ADM cells., Results: RA could increased the sensitivity of K562/ADM cells to adriamycin(the reversal factor was 1.61 times), the difference showed statistically significantly (P<0.05); the resistance factor of K562/ADM to ADM was 41.76 times. The expression of MDR1 mRNA in K562 cells was extremely low, and the protein product P-glycoprotein (P-gp) was almost not expressed; MDR1 mRNA and P-gp in K562/ADM cells were highly expressed; RA could down-regulate the expression levels of MDR1 and P-gp in K562/ADM cells. In addition, RA could upregulate the phosphorylation levels of p38 and ERK1/2 in K562/ADM cells, but it has no effect on the expression of p-JNK., Conclusion: RA may participate in the regulation of MAPK signaling pathway by upregulating the expression levels of p-p38 and p-ERK1/2 in K562/ADM cells, and thus inhibit the transcription and translation levels of MDR1, and finally reverse the multidrug resistance of leukemia cells.

Multi-drug resistance(MDR)refers to the loss of sensitivity of tumor cells to traditional chemotherapeutics agents under the mediation of various mechanisms,resulting in the reduction of chemotherapy efficacy.Current studies suggest that a variety of factors,including cell membrane transporter-mediated efflux of anti-tumor drugs,special microenvironment in tumor tissue,DNA self-repair and anti-apoptotic process,and epithelial-mesenchymal cell transformation,may contribute to the formation of MDR.Cell membrane transporter-mediated drug efflux refers to an increase in the amount of anti-tumor drug pumped out of the cell through the up-regulation of the ATP-binding cassette transporter on tumor cell membrane,which reduces the concentration of the drug in the cell,thus forming MDR.An effective method to inhibit the efflux pump caused by overexpression of membrane transporters plays an important role in overcoming MDR.As a promising drug delivery system,multifunctional nanoparticles have demonstrated many advantages in antitumor therapy.Meanwhile,nanoparticles with tailored design are capable of overcoming MDR when combined with a variety of strategies.This paper described in detail the studies relevant to the use of multifunctional nano-sized drug delivery system combined with different strategies,such as co-delivery of agents,external responsiveness or target modification for intervention with efflux pump in order to reverse MDR.This paper provides reference for the development of nano-sized drug delivery system and the formulation of reversal strategy in the future.

With the emergence of drug resistance in Western medicine, the repeated administration of clinical first-line drugs becomes more severe. There are many factors leading to multidrug resistance(MDR), so it is very difficult to solve the problem. Since traditional Chinese medicine(TCM) has been used in the field of MDR in recent years, the research on the transporter-associated drug resistance and intervention of TCM has gradually become a hot spot. Therefore, in order to further explore the relationships among drug resistance, transporters, and TCM intervention, we review the relevant research progress in recent years and comb the achievements and limitations of this research at present. In the end, we put forward the research direction of changing body's ADME through the host's transporters and gastrointestinal flora, which provides new ideas for future research.

Objectives: To investigate the effect of adriamycin (ADM), idelalisib or ADM and their combination on cell proliferation and intracellular concentration of ADM, and to explore the reversal effect of idelalisib on drug resistance to ADM., Methods: The K562 and K562/ADM cells were respectively treated with ADM and idelalisib at different concentrations. The 50% inhibitory concentration (IC 50 ) and drug resistance index (RI) of ADM to the 2 kinds of cells were measured by methyl thiazolyl tetrazolium (MTT) assay. Non-cytotoxic dose (cell inhibition rate <5%) of idelalisib in the 2 kinds of cells was determined. Then the K562 and k562/ADM cells were divided into the following groups: a K562 cells + ADM group, a K562 cells + ADM + idelalisib group, a K562/ADM cells + ADM group, and a K562/ADM cells + ADM + idelalisib group. The survival rates, the intracellular ATP levels, and the relative concentration of intracellular ADM were detected by MTT method, ATP bioluminescence assay (ATP-BLA) and flow cytometry (FCM), respectively., Results: The cell survival rates were significantly decreased in a dose-dependent manner when the cells were treated with different doses of ADM (0.001-10.000 mg/L ). The IC 50 value of ADM in the K562 and K562/ADM cells were 0.2 mg/L and 1.0 mg/L, respectively. The RI value was 5. The cell survival rates were also significantly decreased in a dose-dependent manner when the cells were treated with different doses of idelalisib (1-50 μmol/L). The non-cytotoxic dose of idelalisib in the K562 and K562/ADM cells were 25 μmol/L and 15 μmol/L, respectively. The cell survival rates in the ADM+ idelalisib group was less than that in the ADM group ( P <0.05)；while there was no statistical difference between the ADM+ idelalisib group and the ADM group in the K562 cells ( P >0.05). The intracellular ATP level in the K562 cells was about (91.502±0.479) mmol/L, and that in the K562/ADM cells was about (24.311±0.349) mmol/L. The intracellular ATP level in the ADM+ idelalisib group in the K562/ADM cells was less than that in the ADM group ( P <0.05); but there was no statistical difference between the ADM + idelalisib group and the ADM group in the K562 cells ( P >0.05). The absorption of intracellular ADM in the ADM + idelalisib group in the K562/ADM cells was more than that in the ADM group ( P <0.05); but there was no statistical difference in the K562 cells between the 2 groups ( P >0.05). The exclusion of intracellular ADM in the ADM + idelalisib group in the K562/ADM cells was less than that in the ADM group ( P <0.05 or P <0.01)；but there was no statistical difference in the K562 cells between the 2 groups ( P >0.05)., Conclusions: Idelalisib exerts effect on inhibition of the proliferation in myeloid leukemia K562 and K562/ADM cells, which may partially reverse the drug resistance of K562/ADM cells to ADM. The mechanisms for the effect of idelalisib may be related to increasing the accumulation of ADM and inducing the cell apoptosis in the K562 and K562/ADM cells.

To prepare peptide-modified chitosan tetramethylprazine nanoparticles(FGF-CS-TMP-NPS) and investigate its reversal effect on multidrug resistance in tumor cells. The pEGF-CS-TMP-NPs were prepared by ion crosslinking method, and their physicochemical properties were investigated. Western blot was used to detect the expression levels of epidermal growth factor receptor(EGFR)(MCF-7, MCF-7/ADR, K562 and K562/ADR) and drug-resistant related protein P-gp. MCF-7/ADR and K562/ADR were selected as cell models. The cytotoxicity of pEGF-CS-TMP-NPs, the multiple of cell resistance to adriamycin, the reversal resistance index of pEGF-CS-TMP-NPs to doxorubicin and the sensitization of pEGF-CS-TMP-NPs to doxorubicin were detected by MTT assay. After MCF-7/ADR and K562/ADR were treated with pEGF-CS-TMP-NPs, the expression changes of P-gp were detected by Western blot. The encapsulation efficiency and drug loading of pEGF-CS-TMP-NPs were 37.66%± 0.53% and 3.25%± 0.34% respectively in HPLC. The nanoparticles showed an average particle size of(150.50±9.3) nm, polymer dispersity index of(0.059±0.007) and Zeta potential of(19.30±2.02) mV as detected by laser particle size analyzer. The nanoparticles were spherical and well dispersed under transmission electron microscope. Western blot results showed that EGFR was positively expressed in MCF-7 and MCF-7/ADR cells, while negatively expressed in K562 and K562/ADR cells. P-gp was highly expressed in MCF-7/ADR and K562/ADR, while negatively expressed in MCF-7 and K562. pEGF-CS-TMP-NPs had a weak effect on MCF-7/ADR and K562/ADR. The adriamycin resistance of MCF-7/ADR cells was 108.36 times, and that of K562/ADR cells was more than 100 times. When IC&#95;(85) of pEGF-CS-TMP-NPs was used as the administration concentration, the reversion index of MCF-7/ADR and K562/ADR cells was 3.68 and 1.87, respectively. pEGF-CS-TMP-NPs could enhance the sensitivity of adriamycin to MCF-7/ADR cells in a positive correlation with the concentration, and the sensitivity was significantly higher than that of K562/ADR cells. Western blot results showed that the expression level of P-gp in MCF-7/ADR cells decreased significantly after treatment with pEGF-CS-TMP-NPs, while the expression level of P-gp in K562/ADR cells did not change significantly. Experimental results show that pEGF-CS-TMP-NPs have an active targeting effect on MCF-7/ADR cells with high EGFR expression, and can effectively reverse the multidrug resistance of MCF-7/ADR cells. Active targeting effect is related to the peptides modification of nanoparticles, and the mechanism of reversing tumor MDR may be achieved by down-regulating the expression level of P-gp.

Abstract　　Chronic myeloid leukemia (CML) is a malignant myeloproliferative tumor which is originating from hematopoietic stem cells. Chemotherapy is the preferred made of treatment for the disease. However, in recent years, more and more patients have multidrug resistance (MDR) during treatment, which is the main cause of failure treatment, therefore, the search for effective reversal agents has important clinical significance. Traditional Chinese medicine derived reversal agents have the characteristics of multiple targets, low toxicity and high efficiency, which can reverse the drug resistance through different mechanisms, and the research potential is unlimited. In recent years, it has been widely concerned by scholars at home and abroad, especially the research on physcion, emodin, curcumin, matrine, gambogic acid, oridonin, ligustrazine, solanine and other monomers, which has made great advance. In this reviwe, the recent research advance on the reversal of MDR in chronic myeloid leukemia by Chinese medicine monomer is summarized briefly.

Objective: To investigate the effect of Bmi-1 gene silencing on drug resistance of leukemia cell K562/ADR and to explore its possible mechanism., Methods: After two sequences of Bmi-1-siRNA were transfected into drug-resistant K562/ADR cells, the mRNA and protein expressions of Bmi-1 gene were detected. After Bmi-1 gene silencing the expression of P-gp and MDR1 were detected and the accumulation of doxorubicin in K562/ADR cells were detected by flow cytometry to determine the effect of Bmi-1 gene silencing on drug resistance of K562/ADR cells. The protein expression of NF-κB was analyzed after Bmi-1 gene silencing. Then after K562/ADR cells were treated with NF-κB inhibitor PDTC, the protein expression of P-gp and its functional changes were analyzed to determine the effect of NF-κB on drug resistance of leukemia cells. The protein expressions of PTEN, AKT and p-AKT after Bmi-1 gene silencing were detected and the effect of Bmi-1 gene silencing on PTEN/PI3K/AKT signaling pathway in drug-resistant cells was determined. After K562/ADR cells were treated with PI3K/AKT pathway inhibitor LY294002, the protein expressions of NF-κB and P-gp were analyzed to determine the regulation of AKT on the expression of NF-κB and P-gp. The protein expressions of AKT, p-AKT, NF-κB and P-gp were detected after the Bmi-1-siRNA transfected cells were treated by PTEN inhibitor BPV. Above-mentioned expression of mRNA was detected by RT-PCR, and the protein expression was detected by Western blot., Results: The expression of Bmi-1 gene in K562/ADR cells decreased at both mRNA and protein levels and the doxorubicin accumulation increased after Bmi-1 gene silencing. The expression of MDR1/P-gp in Bmi-1-siRNA transfected cells was lower than that in K562/ADR cells (P＜0.05). After Bmi-1 gene silencing, the activity of NF-κB decreased. The activity of NF-κB and P-gp expression was inhibited and the function of P-gp in K562/ADR cells was reduced by using NF-κB inhibitor (PDTC). The protein expression of PTEN increased while the protein expression of p-AKT decreased after Bmi-1 gene silencing (P＜0.05). The protein expressions of p-AKT, P-gp and the activity of NF-κB were inhibited significantly by using PI3K/AKT inhibitor LY294002 (P＜0.05). After the Bmi-1-siRNA transfected cells were treated by PTEN inhibitor BPV, the activity of NF-κB and the protein expressions of P-gp were restored., Conclusion: Bmi-1 plays a key role in MDR-mediated multidrug resistance in K562/ADR cells, which may be mediated by activating PTEN/AKT pathway to regulate NF-κB.

Objective: To identify the chaperone of polypyrimidine tractor-binding protein-associated splicing factor (PSF) in myeloid leukemia cells, and to explore the mechanism and redistributive pattern to cell surface of PSF in chemo-sensitive HL60 cells and resistant HL60/DOX cells., Methods: The eukaryotic expression vector of PSF was transfected with liposomes transiently, then flow cytometry was used to detect the expression level of PSF on the cell surface 24 h, 48 h and 72 h after vector transfections. We constructed a chimeric expression vector, streptavidin binding peptide (SBP)-PSF, meanwhile this vector was transfected and made SBP-PSF fusion protein overexpress. In addition, we used streptavidin magnetic beads to precipitate the cellular chaperonin of PSF and then identified its chaperonin by mass spectrometry (MS). Lentiviral vectors containing cytokeratin18 (K18) interference sequences were transfected into 293T cells to prepare lentivirus. HL60 and HL60/DOX cells were infected with lentivirus to obtain stable interfering K18 cell lines. Next, flow cytometry was used to test the membrane relocation level of PSF. Together, these methods confirmed the similar or different mechanisms of the PSF redistributing to membrane synergistically mediated by K18 in HL60 and HL60/DOX cells., Results: The expression of membrane relocated PSF was detected every day for three days (at the end of 24 h, 48 h and 72 h) after transient overexpression. The expressing rate of PSF on the cell surface was 22.4%±3.5%, 37.9%±6.0%, 58.3%±8.8%, respectively in sensitive HL60 cells, while that was 4.7%±0.5%, 3.9%±0.6%, 2.9%±0.6% , respectively in resistant HL60/DOX cells. The difference of expressing rate on each day was significant, P<0.01. We identified K18 detected by co-immunoprecipitation and mass spectrum assay which was the cellular chaperone of PSF. We found that K18 knockdown decreased the PSF expression level which redistributed on cell surface from 48.9%±5.4% to 6.2%±1.0% in sensitive HL60 cells, and from 9.11%±1.2% to 2.21%±0.51% in resistant HL60/DOX cells, respectively., Conclusion: K18 is the intracellular chaperonin of PSF. The interaction of PSF and K18 mediates its redistribution to cell membrane in sensitive cells. While in resistant cells, PSF failed to relocate at the cell surface and accumulated in cells, which mediated resistance to chemotherapeutics.

Purrose: To investigate the effect of dihydroartemisinin (DHA) on multidrug resistance of human oral squamous cell carcinoma cell line KBV200 and to explore its relationship with ROS-MAPK pathway., Methods: MTT assay was used to detect the effects of different concentrations of DHA on proliferation of KB and KBV200 cells. MTT assay was used to detect the inhibition rates of cisplatin (DDP), vincristine (VCR), adriamycin (ADM), etoposide (VP-16) on proliferations of KB and KBV200 cells and the changes after DHA addition, combined with ROS inducer 3-AT, ERK inhibitor UO126, JNK inhibitor SP600125, and p38MAPK inhibitor SB203580, respectively, the difference of reversal before and after intervention was observed; the fluorescence intensity of ROS was measured by flow cytometry. SPSS 17.0 software package was used to analyze the data., Results: Compared with KB cells, drug resistances of KBV200 cells to VCR, VP-16 and ADM were significantly increased(P<0.05), after 10, 20, and 30 μg/mL DHA treatment; the IC50 of KBV200 cells to VCR, VP-16 and ADM was decreased significantly in a concentration-dependent manner(P<0.05). Compared with KB cells, ROS fluorescence intensity of KBV200 cells decreased(P<0.05); after DHA treatment, ROS fluorescence intensity increased significantly, IC50 of VCR, VP-16, ADM decreased significantly(P<0.05), which was consistent with ROS promoter effect. Compared with KB cells, the levels of p-ERK/ERK, p-JNK/JNK, p-p38MAPK/p38MAPK in KBV200 cells increased significantly (P<0.05); after DHA treatment, the levels of p-ERK/ERK, p-JNK/JNK, p-p38MAPK/p38MAPK decreased significantly, IC 50 of VCR, VP-16, and ADM increased significantly(P<0.05); after adding ERK inhibitor UO126, JNK inhibitor SP600125, and p38MAPK inhibitor SB203580, IC 50 of VCR, VP-16, and ADM to KBV200 cells were further reduced., Conclusions: Dihydroartemisinin may reverse multidrug resistance of KBV2001 cells by promoting ROS production and inhibiting MAPK pathway.

Objective: To explore the reversal effect of pioglitazone (PIO) on multidrug resistance in K562/ADR cells and its mechanism., Methods: The proliferation inhibition rate, half inhibition concentration (IC 50 ) and drug-resistance reversal multipe were detected and the curve of proliferation inhibition rate was drawn by MTT assay, the transcription of PPARγ, CYP2C8 and CYP2J2 genes was detected by RT-PCR; the expression of PPARγ, CYP2C8 and CYP2J2 proteins was detected by Western blot., Results: The IC 50 of PIO on K562 and K562/ADR cells for 60 h was 326.7 μmol/L and 349.1 μmol/L respectively. The reversal multiple of 30 μmol/L PIO on ADR-resistance of K562/ADR cells was 6.4. After treatment of K562/ADR cells with PIO, the transcription of CYP2C8 and CYP2J2 and the protein expression of CYP2C8 and CYP2J2 significantly decreased, the transcription of PPARγ gene and the expression of PPARγ protein were not changed., Conclusions: Pioglitazone can reverse the adriamycin-resistance in K562/ADR cells that is closely related to the decrease of protein expression of CYP2C8 and CYP2J2. Pioglitazone is an effective multidrug resistance reversal agent for tumors.

Objective: To explore the effect of Bushen Yanggu Decoction (BYD) on drug resistance and proliferation of human multiple myeloma-resistant KM3/BTZ cells., Methods: Human multidrug-resistant KM3/BTZ cells were established by Bortezomib (BTZ) gradient induction. The effects of commonly used chemotherapeutic drugs and serum containing Bushen Yanggu Decoction (BYD) on the proliferation of KM3 cells and KM3/BTZ cells were detected by MTT assay. RT-qPCR and Western blot were used to detect the expression of Par-4, HSP27 and P-gp genes. Flow cytometry was used to detect cell apoptosis., Results: The established KM3/BTZ cells could produce varying degree of resistance to commonly used chemotherapeutic drugs. Among them, the highest resistance index (RI) to BTZ was 20.269. MTT assay showed that the proliferation of KM3/BTZ cells treated with serum containing Bushen Yanggu Decoction was inhibited, and the inhibitory effect increased with the serum concentration incranse of Bushen Yanggu Decoction. The serum containing Bushen Yanggu Decoction could inhibit the proliferation of KM3/BTZ cells, and induce apoptosis, significantly reduce the drug-resistance of KM3/BTZ cells, up-regulate the expression of Par-4, down-regulate the expression of HSP27 and P-gp., Conclusion: Bushen Yanggu Decoction can effectively inhibit the proliferation of KM3/BTZ cells and induce apoptosis. Bushen Yanggu Decoction can effectively reverse the multidrug-resistance of KM3/BTZ cells. The mechanism may be related with the decrease of expression of HSP27 and P-gp and the increase of expression of Par-4.

Most of the intra-abdominal infections are benign and critical diseases caused by trauma, surgery and gastrointestinal diseases, which require the attention of surgeons. The increase of drug resistance of pathogens is a common clinical problem. The intra-abdominal infection caused by multidrug-resistant bacteria is a huge challenge faced by clinicians, and is mainly found in hospital-acquired abdominal infections, of which gram-negative bacteria are the most common. This paper firstly summarizes the common types, early diagnosis and risk factors of multidrug-resistant bacteria according to the literature, and then describes the treatment strategy of intra-abdominal infection caused by multidrug-resistant bacteria from four aspects: anti-infective medication, infection source control, resuscitation and organ support, and nutritional support treatment. In addition, we should promote gastrointestinal function recovery through nutritional support treatment and prevent intestinal source infection, on the basis of understanding the risk factors of multidrug-resistant infection, rational use of anti-infective medication and infection source control measures. At the same time, proper organ function support can help to improve the success rate in the treatment of multidrug-resistant intra-abdominal infection.

To investigate the effects of Gegen Qinlian decoction on the expression of P-glycoprotein (P-gp) and multi-drug resistance protein (MRP) in epithelial cells of human colon adenocarcinoma Caco-2 cells．The effects of different concentrations of Gegen Qinlian decoction on the expression levels of p-gp and MRP1-6 mRNA in Caco-2 cells were detected by real time quantitative reverse transcriptase PCR (qRT-PCR).12 h after drug treatment (5.00 g·L⁻¹), the expression levels of MDR1 and MRP1-6 were significantly down-regulated at concentration of 5.00 g·L⁻¹; the mRNA expression levels of MDR1，MRP1，MRP2，MRP4，MRP5 and MRP6 were significantly down-regulated at concentration of 2.50 g·L⁻¹; only the expression levels of MRP2 and MRP5 were significantly affected at concentration of 1.00 g·L⁻¹. The results showed that the expression levels of MDR1 and MRP1-6 mRNA in Caco-2 cells could be down-regulated in a dose-dependent manner. Gegen Qinlian decoction may reduce drug efflux by down-regulating the mRNA expression of cell transporters in Caco-2 cell, and increase the time of drug action, thereby enhancing the bioavailability of chemotherapeutic drugs., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To explore the effects of icariin on the proliferation and apoptosis abilities of human ovarian cancer cells SKOV3 and multi-drug resistant SKVCR cells., Methods: Human ovarian cancer cells SKOV3 and multi-drug resistant SKVCR cells were treated with various concentrations of icariin. The inhibitory concentration and the half maximal inhibitory concentration were detected by CCK8 kit. The proliferation and apoptosis abilities of SKOV3 and SKVCR cells were measured by flow cytometry. The migration and invasion abilities of SKOV3 and SKVCR cells were evaluated by Transwell assays. The protein expression level of Caspase-3 was detected by Western blot analysis., Results: Icariin significantly suppressed the proliferation abilities of SKOV3 and SKVCR cells in a dose-dependent manner at variant levels from 5-100 μg/mL. SKOV3 and SKVCR cells were treated with 19.5 μg/mL icariin and 48.4 μg/mL icariin (0.8×IC 50 ) for 48 h, respectively. The results showed that the cell proliferation, migration and invasion abilities were markedly decreased comparing with control group, and the apoptosis rate was significantly increased as compared with control group ( P <0.05). Western blot results indicated that icariin significantly increased the protein expression level of caspase-3 in SKOV3 and SKVCR cells ( P <0.05)., Conclusion: Icariin suppressed the proliferation, migration and invasion abilities of human ovarian cancer cells. Increasing expression of Caspase-3 might be the mechanism of its enhancement of apoptosis., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Science Edition).)

Objective: To explore the alteration of plasma metabolomic profiles, screen the new serum markers of multidrug resistant epithelial ovarian cancer (EOC), and investigate the mechanism. Methods: The serum of 132 cases with cisplatin-resistant EOC, cisplatin-sensitive EOC, benign ovarian cyst and healthy donors were collected. Differentially plasma metabolic profiles were identified by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). The significantly different metabolites of each group were screened by using principal component analysis. Then compounds that played a key role in cisplatin resistance were identified by using nuclear magnetic resonance (NMR). The relationships between these compounds and clinical characteristics and prognosis were analyzed. Results: LC-MS/MS identified 25 800 metabolic compounds. According to the descending dimension algorithm by principal component analysis, six compounds which were the biggest contributor to grouping were identified. The identified results of NMR showed that the serum level of C16 Sphinganine was lower while Dodemorph was higher in the EOC than those of the normal control. Compared to the cisplatin sensitive group, cisplatin resistant group exhibited a specific metabolic trait characterized by upregulation of 1-Monopalmitin, Ricinoleic acid methyl ester, Polyoxyethylene (600) mono-ricinoleate/Glycidyl stearate and downregulation of Calycanthidine. The four components were all associated with fatty acid metabolism, and the combinational diagnostic sensitivity of these biomarkers for cisplatin-resistance was 86.50% and the specificity was 81.80%, the area of receiver operating characteristic (ROC) curve was 0.93. Conclusions: The metabolic signatures of normal control, benign ovarian cyst, cisplatin sensitivity and cisplatin resistance can be clearly separated from each other by LC-MS/MS technology.The combinational four biomarkers including Calycanthidine, 1-Monopalmitin, Ricinoleic acid methl ester and Polyoxyethylene (600) mono-ricinoleate/Glycidyl stearate are more sensitive and specific for the diagnosis of cisplatin resistant EOC, and may provide the potentially predict markers of chemotherapeutic response in metabolic level. The fatty acid metabolism may participate in the cisplatin resistant progression of EOC.

Objective: To investigate the reversing effect of icaritin on multidrug resistance of multiple myeloma cell lines KM3/BTZ and its underlying mechanism., Methods: KM3/BTZ cells were established by a gradually ascending gradient induction of bortezomib (BTZ). The sensitivities of KM3 and KM3/BTZ cells to 7 chemotherapeutic drugs, the inhibition and reversal effects of icaritin on proliferation and drug-resistance of KM3/BTZ cells were analyzed by MTT. The apoptosis was analyzed by flow cytometry, and the expression of Par-4, HSP27 and P-gp were detected by Western blot., Results: KM3/BTZ cells were not only resistant to BTZ, but also to other 6 chemotherapeutic drugs. The resistance index (RI) to BTZ was 17.84, and higher than that of other chemotherapeutic drugs. Icaritin inhibited the proliferation and induced the apoptosis of KM3/BTZ cells. The IC 50 value of BTZ decreased from 0.345 µg/ml to 0.149 µg/ml, and the reversal index was 2.38 (P<0.05). The expression of Par-4 protein increased in a concentration-dependent manner, while the expression of HSP27 and P-gp were down-regulated., Conclusion: Icaritin can inhibit cell proliferation and induce apoptosis of KM3/BTZ cells, moreover, can effectively reverse the multidrug resistance of KM3/BTZ cells. The mechanism may be related with down-regulation of HSP27 and P-gp expression, and up-regulation of Par-4 expression.

Objective: To investigate the mechanism of reversing drug resistance of K562/D cells to daunorubicin by Embelin and its relationship with P-gp and MDR1 mRNA., Methods: MTT assay was used to detect and compare the cell proliferation rate of treating with DNR alone and DNR combined with Embelin. Flow cytometry with Annexin V-FITC/PI double staining was used to detect cell apoptosis rate, Western blot was used to detect the expression of XIAP,Caspase-3,BCL-2,BAX and P-gp of K562/D cells after using DNR alone and combining with Embelin. Quantitative real-time PCR was used to detect XIAP,BCL-2,BAX and MDR1 mRNA., Results: The IC 50 of K562 and K562/D cells treated with DNR for 24 h were 2.177 µg/ml and 69.43 µg/ml, respectively. The drug-resistance index was 31.89; The proliferation inhibition rates of K562/D cells treated with Embelin of 3, 10, 30, 100 and 300 µg/ml for 24 h were 2.70%±1.08%, 10.92%±4.89%, 28.13%±2.09%, 36.56%±3.24% and 43.59%±1.16%; The proliferation inhibition rates of K562/D cells treated with DNR of 0.1, 1, 10 and 100 µg/ml combined with 10 µg/ml Embelin for 24 h were 31.92%±3.29%, 49.57%±6.87%, 55.16%±0.78% and 71.94%±3.89%. The IC 50 was 2.11 µg/ml respectively. The reverse index was 32.91. The apoptosis rates of K562/D cells treated with 0.1 µg/ml DNR alone or combined with Embelin of 10 µg/ml and 30 µg/ml for 24 h were 12.06%±0.95%, 27.54%±0.59% and 39.59%±1.57%, respectively. The results of Western blot showed that after combination of DNR with Embelin, the expression of Caspase-3 was significantly down-regulated (P<0.05), moreover, the prolifiration inhibition effect of drug combination on cells could be countreacted by Z-VAD-FMK, at the same time the expression of XIAP and BCL-2 protein was significantly down-regulated(P<0.05), the expression of BAX protein was significantly up-regulated(P<0.05), while there was no change of P-gp expression later (P<0.05). The results of RT-PCR showed that after combination of DNR with Embelin, expression of XIAP and BCL-2 mRNA was significantly down-regulated(P<0.05), expression of BAX mRNA was significantly up-regulated(P<0.05), while there was no obvious change of MDR1 mRNA expression(P>0.05)., Conclusion: The down-regulation of XIAP contributes to enhance the effect of DNR on K562/D cells, the mechanism of Embelin-reversing the drug-resistence of K562/D cells to DNR does not relate with P-gp and MDR1 mRNA.

The present research was launched to investigate the effects of 12 annonaceous acetogenins (ACGs) on human hepatic carcinoma cell line SMMC-7721/ADR, and to find out their structure-activity relationship. SMMC-7721/ADR cells were treated with 12 ACGs including annosquamin A(1)，annosquamin B(2)，annotemoyin-1(3)，uvariamicin Ⅱ(4)，annosquacin D(5)，annosquacin B(6)，isodesacetyluvaricin(7)，uvarigrandin A(8)，squamostatin D(9)，squamostatin E(10)，squamostatin A(11)，and 12,15-cis-squamostatin A(12) for 24 h, and the different expression of the target gene NDUFV2 were detected by quantitative real-time PCR. All the tested compounds made the expression of the target gene NDUFV2 decreased on human hepatic carcinoma cell line SMMC-7721/ADR, of which the bistetrahydrofuran ACGs showed the best activity,which the non-adjacent bistetrahydrofuran ACGs displayed the worst activity.The ACGs with the reducing number of carbons between γ-unsaturated lactone and the close tetrahydrofuran (THF) ring are more potent. For bistetrahydrofuran ACGs with the same nucleus skeleton,they would be more active as more hydroxyls on aliphatic chain, which for the non-adjacent bistetrahydrofuran ACGs with less hydroxyls on aliphatic chain that would be more active. ACGs with 3 hydroxyls on aliphatic chain would be more active. ACGs with threo configuration are more active than erythro configurotion, and the compounds with cis THF ring seem to be superior to those of trans THF ring. Furthermore, the ACGs with the reducing number of carbons between terminal methyl and the close tetrahydrofuran (THF) ring are more potent., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To explore the synergistic anti-tumor mechanism of astragalus polysaccharids(APS) combined with doxorubicin in HL-60/A cells., Methods: The phenotype of HL-60/A was identified by using RT-PCR, Wester blot and CCK-8, the antitumor effect of astragalus polysaccharids combined with doxorubicin on HL-60/A cells was detected by CCK-8, the apoptosis of HL-60/A after treating with different drugs was detected by Annexin-V, the caspase casade activation was detected by Wester blot, the effect of astragalus polysaccharids on expression and function of multidrug resistance protein (MRP) was detected by using real-time quantitative PCR and Western blot., Results: HL-60/A cells displayed obvious characteristics of resistance to doxorubicin, whose resistance were about 27 times that of its sensitive cell line HL-60. In addition, it was further found that astragalus polysaccharids could obviously increase the cell growth inhibition, induce cell apoptosis and caspase cascade activation, decrease the expression of MRP and increase the drug concentration in HL-60/A when combined with doxorubicin., Conclusion: Astragalus polysaccharids combined with doxorubicin can effectively overcome the drug resistance of HL-60/A. The mechanism may be associated with decreasing the expression of MRP, inhibiting drug efflux and increasing the intracellular drug concentration, then inducing HL-60/A cell apoptosis.

This study was designed to reverse multidrug resistance of lung cancer cells by downregulating MDR1 genes through RNA interference (RNAi) technology. A novel biodegradable cationic polymer (PEG- b- PLG-g-PEIs, GGI) was synthesized and characterized by 1H NMR. The particle size and zeta potential were measured by dynamic light scattering (DLS). The cell viability profile of GGI was tested by MTT method with both A549 and A549/DDP cell lines. Flow cytometry (FCM) technology was used to investigate the efficiency and intensity of delivering siRNA to cells by GGI polymer. RT-PCR and Western blot were used to detect the mRNA and P-gp expression after GGI/MDR1 siRNA transfection assay. The sensitivity of cisplatin administration after transfecting GGI/MDR1 siRNA polyplexs was performed with MTT and Annexin V-FITC/PI methods. The results suggest that the particle size and zeta potential of GGI/siRNA were 150 −200 nm and 16−28 mV. GGI exhibited a lower cell cytotoxity than PEI 25K and higher efficiency of delivering siRNA, which dramatically decreased the expression of MDR1 mRNA and P-gp of A549/DDP cells and increased much sensitivity to cisplatin in A549/DDP cells. GGI holds a great potential in gene delivery as a novel cationic polymer for further investigation.

Objective: To identify Plasmodium falciparum multidrug resistance 1（Pfmdr1） point mutations in imported Plasmodium falciparum in Wuhan., Methods: Blood samples were collected from returnees infected with P. falciparum in endemic areas of Africa and Myanmar during 2010-2015 in Wuhan City. Nested PCR primers were specifically designed for Pfmdr1 gene loci 86, 1042 and 1246 of P. falciparum. The Pfmdr1 gene was then amplified by nested PCR, and the products were digested by restriction enzyme ApoⅠ, AseⅠ and EcoRⅤ, respectively. The mutation rate for loci 86, 1042 and 1246 was analyzed. Results A total of 187 patients with falciparum malaria were involved in the study. Pfmdr1 was amplified from all the blood samples. Restriction enzyme digestion revealed mutation rate of 19.3%（36/187）, 4.3% （8/187） and 9.6%（18/187） for loci 86, 1042 and 1246, respectively. In detail, the mutation rate for loci 86, 1042 and 1246 was 20.6%（36/175）, 2.9%（5/175） and 10.3%（18/175） respectively in the 175 samples from Africa, and only 3 cases with locus 1042 mutation were found in the 12 samples from Myanmar., Results: A total of 187 patients with falciparum malaria were involved in the study. Pfmdr1 was amplified from all the blood samples. Restriction enzyme digestion revealed mutation rate of 19.3%（36/187）, 4.3% （8/187） and 9.6%（18/187） for loci 86, 1042 and 1246, respectively. In detail, the mutation rate for loci 86, 1042 and 1246 was 20.6%（36/175）, 2.9%（5/175） and 10.3%（18/175） respectively in the 175 samples from Africa, and only 3 cases with locus 1042 mutation were found in the 12 samples from Myanmar., Conclusion: The loci 86, 1042 and 1246 mutations of Pfmdr1 have all been found in the samples from Africa, with only one point mutation （locus 1042） found in samples from Myanmar.

Using the BALB/c mouse multidrug resistance model of leukemia, the effect of peptide extract from scorpion venom (PESV) to the upstream signal factors of P-gp of MDR leukemia stem cells on the mouse tumor block was observed, and the mechanism of PESV to reverse the MDR of LSC was studied. At the same time, the expression of P-gp, MDR1 mRNA and PI3-K, NF-κB were respectively detected through flow cytometry, RT-PCR, Western blot and Elisa, and the mouse liver, spleen were examined via histopathological methods. The results of the experiment were as follows: mice of the control group didn't show any obvious changes, while mice of the other six groups all showed arched back, emaciation, liver swell, and inflammation was found in all liver tissue. The expression level of P-gp and PI3K on the LSC membrane of mouse tumor block was down-regulated; the expression of MDR1 mRNA in the cytoplasm was obviously down in the PESV low dose group, and which was inordinately up in the middle dose group and the high dose group. The expression level of NF-κB in the leukemia stem cell nucleus remarkably decreased. PESV had a outstanding role of down-regulating PI3K, NF-κb, MDR1 which were all upstream factors of P-gp, and to a certain degree enhanced the sensitivity of LSC to ADM. Therefore, this experiment explained one of the mighty mechanism of PESV to reverse MDR of LSC, and provided a foundation to further study of combinational anti-cancer effects of PESV., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To analyze the protein expression differences between colonized multidrug-resistant acinetobacter baumannii (MDR-AB) and infectious MDR-AB using comparative proteomics and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and to explore the molecular characteristics of MDR-AB infections. Methods: A total of 59 MDR-AB strains including 23 of bloodstream infections MDR-AB and 36 of nasal, pharyngeal or environmental colonization MDR-AB were collected from Beijing Tongren Hospital between January 2008 and December 2011. MALDI-TOF MS cluster analysis was applied to identify the differences of protein expression between infection strains and colonization strains (including patient colonization and environmental colonization) of MDR-AB. Two-dimensional protein differences electrophoresis and MALDI-TOF-TOF MS were used to analyze the protein expression differences between bloodstream infection strain and nasal colonization strain isolated from the same patient. Results: ST92 was the main multiple locus sequence typing of 23 bloodstream infections MDR-AB. Cluster analysis showed that there were differences of protein fingerprint of MADLI-TOF MS between colonized and infectious MDR-AB. Proteomic differences were found between colonization strain and infection strain which were isolated from the same patient. And 9 major different protein spots were identified. They were trigger factor (score of identification was 10 218 and coverage rate was 44%), inosine-5'-monophosphate dehydrogenase (score of identification was 1 919 and coverage rate was 60%), phosphoglycerate kinase (score of identification was 947 and coverage rate was 49%), outer membrane protein 38 (score of identification was 572 and coverage rate was 23%) and so on. Conclusion: There were differences of protein expression between MDR-AB infection strains and colonization strains. And such different proteins could provide experimental evidence for molecular markers research of MDR-AB infections.

Objective: To investigate the reversal effect of dihydromyricetin(DMY) on drug resistance of K562/A02 cells to adriamycin and explore its possible mechanism., Methods: K562 and K562/A02 cells were treated with DMY (5, 10, 20, 40, 60, 80 and 100 mg/L) and ADM (100-0.05 mg/L) for 48 h. The viability of K562 cells and K562/A02 cells was tested and the reversal effect of DMY on drug resistance of K562/A02 cells to adriamycin was analyzed by MTT. The relative concentration of ADM in cells was measured by flow cytometry. Protein expressions of drug resistance related genes including P-glycoprotein (P-gp), multidrug resistance associated protein 1 (MRP1), glutathione transferase π (GSTπ) and BCL-2 were measured by Western Blot., Results: The proliferation of K562 and K562/A02 cells was significantly decreased by DMY in dose-dependent manner as compared with control group (r1=0.37, r2=0.38). The IC 50 of ADM on K562 and K562/A02 cells were 71.23±6.51 and 72.88±5.49 mg/L respectively. DMY (5, 10 and 20 mg/L) was low cytotoxicity. DMY (5, 10 and 20 mg/L) enhanced the sensitivity of K562/A02 cells to ADM in dose-dependent manner (r1=-0.62, r2=-0.71) and the reversal multiples was from 1.38 to 28.591. The relative concentrations of ADM in K562/A02 of DMY (5, 10 and 20 mg/L) group cells were significantly increased in dose-dependent manner compared with the control group (r=0.34). Compared with the control group, the expressions of drug resistance related protein P-gp, MRP1, GSTπ and BCL-2 were significantly decreased in dose-dependent manner in DMY (5, 10 and 20 mg/L) group (r1=-0.41, r2=-0.37, r3=-0.58, r=-0.46). Compared with the ADM group, the protein expressions of drug resistance related genes P-gp, MRP1, GSTπ and BCL-2 in DMY (5, 10 and 20 mg/L)+ADM group were significantly decreased in dose-dependent manner (r1=-0.55, r2=-0.41, r3 =-0.38, r4=-0.44)., Conclusion: DMY enhances the sensitivity of K562/A02 cells to ADM, its mechanism may be related with decrease of P-gp, MRP1, GSTπ and BCL-2 expressions.

Objective: To study the inhibitory effect of serum containing Fuzheng Jiedu decoction on leukemia multi-drug-resistance K562/A02 cells and its possible mechanism., Methods: The MTT method was used to detect the inhibitory rate of K562/AO2 cells treated with serum containing Fuzheng Jiedu decoction; the flow cytometry was used to detect the inhibitory effect of serum containing medicin on growth of K562/AO2 cells and P-gp expression; the Q-PCR was used to assay the BCL-2 mRNA expression; the Western blot was used to detect the BCL-2 protein expression., Results: MTT cytotoxic test showed serum containing Fuzheng Jiedu decoction could inhibit K562/A02 cell growth, and the inhibitory rate increased with the increase of drug concentration; the flow cytometry showed that the serum containing Fuzheng Jiedu decoction could promote K562/A02 cell apoptosis in a concentration-dependent manner. qPCR and Western blot showed that serum containing Fuzheng Jiedu decoction could down-regulate the protein expression of BCL-2. Fuzheng Jiedu decoction could reduce the protein expression of P-gp on the K562/A02 cell membrane., Conclusion: serum containing Fuzheng Jiedu decoction can promote K562/A02 cell apoptosis, its mechanism of inducing apoptosis may be related with the inhibition of BCL-2 and P-gp protein expression.

Objective: To investigate the reversal effect of inhibition of nuclear factor-kappa B (NF-κB) gene transcription by specific miRNA on multi-drug resistance (MDR)of liver cancer. Methods: The expression of P-glycoprotein (P-gp) and NF-κB in hepatoma cells, drug-resistant HepG2/ADM cells, and liver cells (LO2 cells) was analyzed. Specific NF-κB miRNA plasmids were constructed, screened, and transfected into HepG2 or HepG2/ADM cells. Western blot was used to measure the concentrations of P-gp and NF-κB, and FQ-PCR was used to measure gene expression; Cell Counting Kit-8 assay was used to measure cell proliferation and the influence of drugs on cell proliferation; flow cytometry and Annexin-V-PE/7-ADD double staining were used to observe cell cycle and apoptosis. The t-test was used to compare means between groups, and a one-way analysis of variance was used to compare means between multiple groups. Results: After being treated by adriamycin, hepatoma cells showed increased expression of P-gp and an increased level of NF-κB phosphorylation. At 24, 48, and 72 hours, the resistance index of the HepG2/ADM cells ( IC 50 = 4.166, 1.522, and 1.380 μmol/L) was 8.519, 6.874, and 6.166 times that of the HepG2 cells ( IC 50 = 0.489, 0.221, and 0.224 μmol/L). The HepG2/ADM cells showed significantly higher relative mRNA expression (∆ct value) of mdr1 and NF-κB than the HepG2 cells (3.310±0.154/2.580±0.040 vs 0.084±0.038/0.6067±0.032, both P < 0.01). After being transfected with miRNA1, the HepG2/ADM cells showed significantly lower mRNA expression of mdr1 than the cells in the miRNA-negative group (2 -∆∆ct = 0.326±0.011 vs 0.804±0.057, t = 14.262, P < 0.01), as well as significant reductions in the expression of intracellular t-p65, nuclear p-p65, and P-gp compared with the cells in the miRNA-negative group ( P < 0.01), with inhibited cell proliferation, G1 phase arrest, and increased apoptosis. Conclusion: Abnormal expression of MDR1/P-gp is closely associated with MDR, and inhibition of NF-κB activation by specific miRNA can significantly inhibit MDR1/P-gp gene transcription and reverse MDR of liver cancer.

Objective: To explore the effect of peptide extract from scorpion venom (PESV) to multidrug resistance (MDR) of leukemic stem cell (LSC) in vivo., Methods: K562/A02 cells were cultured and collected in the logarithmic phase. K562/A02 stem cells were screened using immunomagnetic beads for reserve. K562/A02 LSC was injected to 5 of 40 BABL/c nude mice for preparing subcutaneous tumor. The rest 35 nude mice were then randomly divided into 7 groups, i.e., the normal control group, the model group, the Adriamycin (ADM) group, the PESV group, the ADM +high dose PESV group, the ADM + middle dose PESV group, the ADM +low dose PESV group, 5 in each group. Tumor tissue was embedded in all groups except the normal control group. One milliliter normal saline was peritoneally injected to mice in the model group after modeling, once per day. ADM 0. 05 mg was peritoneally injected to mice in the ADM group, once per other day. PESV 2 μg was peritoneally injected to mice in the PESV group, once per day. Mice in 3 ADM + PESV groups were peritoneally injected with ADM 0. 05 mg (once per other day) plus PESV (5, 2, and 1 μg respectively, once per day). All medication lasted for 14 days. P-glycoprotein (P-gp) was detected using flow cytometry. Breast cancer resistance protein (BCRP) and mRNA expression of multidrug resistance 1 (MDR1) were measured using RT-PCR. Aldehyde dehydrogenase 1 (ALDH1) was detected using immunohistochemistry. Phosphoinositide 3-kinase (PI3K) was detected using Western blot. NF-κB content was detected using ELISA., Results: CD34 + CD38-ratio was 31.5% and IC₅₀ was (60.33 ± 10. 68) μg/mL before K562/A02 cells were screened with immunomagnetic beads, while they were 92. 8% and (58. 33 ±9. 72) μg/mL after screen. The tumor formation rate was 100% in modeling mice. Compared with the model group, no statistical difference of each index occurred in the ADM group (P <0. 05). There was statistical difference in BCRP, MDR1 mRNA, or NF-κB factor between the model group and the PESV group (P <0. 05). The expression level of P-gp obviously decreased and the protein expression of P13K was down-regulated in 3 ADM + PESV groups (P <0. 05); mRNA expression of BCRP decreased and mRNA ex- pression of MDR1 obviously increased in the ADM + high dose PESV group and the ADM + middle dose PESV group, with statistical difference (P <0. 05). Protein expression of P13K was down-regulated in the ADM+ high dose PESV group, with statistical difference (P <0. 05). P-gp value, BCRP mRNA expression, MDR1 mRNA expression, PI3K, and NF-κB factor were all obviously down-regulated in the ADM +high dose PESV group, as compared with the ADM group and the PESV group respectively (P <0. 05). There was no statistical difference in ALDH1 positive rate among all groups (P >0. 05). Conclusion PESV combined ADM could down-regulate expression levels of P-gp, BCRP, MDR1, P13K, and NF-κB, strengthen the sensitivity of K562/A02 LSC to ADM in vivo, and reverse MDR of LSC.

Objective: To investigate the role of miR-21 on multidrug resistance (MDR) in non-small cell lung cancer(NSCLC)and to provide experimental and theoretical basis for MDR reversal., Methods: Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to determine the mRNA level of miR-21 both in the chemo-sensitivity cell strain A549 and the chemo-resistance cell strain A549/DDP (primary A549/DDP cells). The miR-21 interference sequence was synthesized and transfected into A549/DDP cells by liposome as the carrier. The miR-21 expression level was knocked down and the change of chemo-sensitivity of cells was detected. Effects of miR-21 on the cell apoptosis and cell cycle in miR-21-depleted A549/DDP cells were analyzed by flow cytometry to elucidate the involvement of miR-21 in MDR reversal in NSCLC. The expression of multidrug-resistant proteins Survivin, Cyclin D1, Epidermal growth factor receptor (EGFR), Multidrug resistance-associated protein1 (MRP1) and Lipoprotein receptor-related protein (LRP) were detected by Western blot., Results: MiR-21 level in multidrug-resistant NSCLC cell line A549/DDP was (5.223±0.316) folds higher than that in A549 cell line (t=48.318, P<0.01). Knockdown of miR-21 in A549/DDP cells significantly reversed their sensitivity to cis-DDP, meanwhile, the value of half maximal inhibitory concentration was significantly decreased compared with control group transfected with empty vector ((22.2±1.2) and (48.6±3.2) μmol/L, t=5.608, P<0.01). Cell apoptosis rate in A549/DDP cell with knockdown of miR-21 was significantly increased compared with primary A549/DDP cell line ((27.7±1.1) % and (16.8±1.1) %, t=10.183, P<0.01). Cell cycle G0/G1 phase in A549/DDP cell with knockdown of miR-21 was significantly decreased compared with primary A549/DDP cell line ((37.5±1.2) % and (43.4±2.3) %, t=8.202, P<0.01). Compared with primary A549/DDP cell line, the expression of Survivin, Cyclin D1, EGFR, MRP1 and LRP in A549/DDP cell with knockdown of miR-21 were significantly decreased ((71.7±4.3)%, t=8.325, P<0.01; (69.4±4.5)%, t=5.162, P<0.01; (52.3±3.2)%, t=8.042, P<0.01; (60.6±4.2)%, t=6.641, P<0.01; (72.9±3.8)%, t=4.566, P<0.01, respectively)., Conclusion: miR-21 silencing reverses the multidrug resistance in lung cancer cell via accelerating cell apoptosis and modulating multidrug resistance-related gene expression. miR-21 may be a potential therapeutic candidate in multidrug resistance patients with lung cancer.

10 kinds of annonaceous acetogenins were selected for antitumor activity testing against human lung cancer cell line A549/Taxol and the structure activity relationship was analyzed.MTT assay was used to detect the inhibitory activities of 10 kinds of annonaceous acetogenins and positive drugs against A549/Taxol cells, respectively uvariamicin-Ⅲ(1), uvariamicin-Ⅱ(2), annosquacin D(3), desacetyluvaricin(4), annosquatin A(5), squamostatin D(6), bullatacin(7), squamocin(8), motrilin(9), annosquatin B(10), verapamil and cisplatin. Annonaceous acetogenins showed significant inhibitory activities against A549/Taxol cells, and were more potent than the positive drug verapamil and cisplatin.The more carbon atoms between the tetrahydrofuran ring and the lactone ring of annonaceous acetogenins exhibited more potency.Besides,ACGs with two substituted hydroxyl showed more potency than the compounds with three substituted hydroxyl in the bis-adjacent-THF ACGs. Furthermore, ACGs with three substituted hydroxyl showed more potency than the compounds with four substituted hydroxyl among the no bis-adjacent-THF ACGs., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Objective: To investigate the expressions of nuclear factor-κB (NF-κB) and P-glycoprotein (P-gp) in patients with liver diseases and the effects and mechanism of intervening NF-κB activation on multiple drug resistance (MDR) reversal., Methods: The levels of circulating NF-κB and P-gp expression were quantitatively detected in 294 patients with liver diseases by using enzyme-linked immunosorbent assay. NF-κB gene transcription in human HepG2 cells was intervened by specific siRNA with/without doxorubicin treatment. Levels of protein or gene expression were analyzed by Western blotting or fluorescence quantitative polymerase chain reaction (PCR)., Results: The dynamic increase of circulating NF-κB and P-gp expressions were observed during patients from chronic hepatitis to cirrhosis to hepatocellular carcinoma (HCC) development. The levels of serum NF-κB and P-gp expression in HCC were significantly higher (P<0.001) than those in cirrhosis, chronic hepatitis, and normal controls. The expression levels of serum NF-κB and P-gp were significantly associated with HBV infection (P<0.05), elevated after interventional chemotherapy with higher frequency or prolonged therapy, and significantly decreased in the post-operative HCC (P<0.001). Both expressions in HepG2 cells were significantly higher after adding doxorubicin in the cell cultures. After the cells were transfected with siRNA, the NF-κB expression was down-regulated at mRNA or protein level with higher sensitivity to doxorubicin., Conclusion: The over-expressions of NF-κB and P-gp are closely associated with MDR formation; intervention of NF-κB activation can inhibit P-gp expression, and enhance the sensitivity to anti-cancer drug and reverse MDR of HCC.

Multidrug resistance (MDR) remains the major obstacle to the success of clinical cancer chemotherapy. P-glycoprotein (P-gp), encoded by the MDR1, is an important part with complex mechanisms associated with the MDR. In order to overcome the MDR of tumors, we in the present experimental design incorporated small interfering RNA (siRNA) targeting MDR1 gene and anticancer drug paclitaxel (PTX) into the solid lipid nanoparticles (SLNs) to achieve the combinational therapeutic effects of genetherapy and chemotherapy. In this study, siRNA-PTX-SLNs were successfully prepared. The cytotoxicity of blank SLNs and siRNA-PTX-SLNs in MCF-7 cells and MCF-7/ADR cells were detected by MTT; and the uptake efficiency of PTX in MCF-7/ADR cells were detected via HPLC method; quantitative real-time PCR and flow cytometry were performed to investigate the silencing effect of siRNA-PTX- SLNs on MDR1 gene in MCF-7/ADR cells. The results showed that PTX loaded SLNs could significantly inhibit the growth of tumor cells, and more importantly, the MDR tumor cells treated with siRNA-PTX-SLNs showed the lowest viability. HPLC study showed that SLNs could enhance the cellular uptake for PTX. Meanwhile, siRNA delivered by SLNs significantly decreased the P-gp expression in MDR tumor cells, thus increased the cellular accumulation of rhodamine123 as a P-gp substrate. In conclusion, the MDR1 gene could be silenced by siRNA-PTX-SLNs, which could promote the growth inhibition efficiency of PTX on tumor cells, leading to synergetic effect on MDR tumor therapy.

Objective: To explore the effect of peimine on excision repair cross-complementation 1 (ERCC1) mRNA and lung resistant protein (LRP) expressions in A549/cisplatin (DDP) multidrug resistance (MDR) cell line., Methods: Lung cancer A549/DDP cells were cultured in vitro.Cells at logarithmic growth phase were divided into 4 groups, i.e., the blank control group, the DDP group, the ligustrazine group (DDP+ligustrazine), the peimine group (DDP + peimine). After 48-h drug action, ERCC1 mRNA expression was detected by RT-PCR and LRP expression detected by cell immunofluorescence., Results: There was no statistical difference in expression levels of ERCC1 mRNA and LRP between the DDP group and the blank control group (P > 0.05). Compared with the DDP group, expression levels of ERCC1 mRNA and LRP obviously decreased in the ligustrazine group and the peimine group (P < 0.05). They were obviously lower in the peimine group than in the ligustrazine group (P < 0.05)., Conclusions: Peimine could reverse MDR of A549/DDP cell line. Its mechanism might be associated with down-regulating ERCC1 mRNA and LRP expression levels.

Objective: To explore the proteomic differences among with and without curcumin treatment of vincristine-resistance HCT-8/VCR cells of human colon carcinoma by using mass spectrometry and two-dimensional gel electrophore-sis (2-DE)., Methods: The total proteins of the both groups were extracted from serum were run in immobilized pH gradient isoelectic focusing (IPG-IEF) at the first dimension.The proteins pots in gels were visualized by silver staining protocol, scanned by using a molecular imager GS-800 calibrated densitometer. The differentially expressed proteins were identified and analyzed by PDQuest 8.0 software. The diferentially displayed protein spots were searched and identifiyed by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS), the interested proteins were further validated by RT-PCR and Western blot., Results: The 2-DE HCT-8/VCR cells patterns were acquired with clear background, well-resolution and reproduction. And 1 070±96 protein spots were detected in control HCT-8/VCR cells and 1 030±69 in curcumin-treated HCT-8/VCR cells. Twenty-nine differential protein spots were found to be differentially expressed. Glutathione S-transferase pi1 gene (GSTP1), a diferentiaI expression protein was identified which one of these proteins. RT-PCR and Western blotting results showed that the expressions of GSTP1 mRNA (0.49±0.09) and protein (0.29±0.07) in curcumin-treated group were significantly lower than in control group (GSTP1 mRNA 1.19±0.21 and protein 0.70±0.13, both P<0.05), indicating that curcumin down regulated these expressions., Conclusions: The suppression of GSTP1 by curcumin could enhance the vincristine chemosensitivity in HCT-8/VCR. GSTP1 overexpression may be involved in the vincristine -resistance of human colon carcinoma cells.

Objective: To explore the expression of PXR (Pregnane X receptor) in several malignant hematological cell lines, and to investigate the reversal effect of Gambogic acid (GA) on multi-drug resistance (MDR) of K562/A02 cell line and its reversal mechanism., Methods: Transcription of PXR was detected by real-time PCR in several malignant hematological cell lines. The growth inhibition rate of K562/A02 in different experimental groups was assayed by MTT method, and the expression of PXR protein was measured by Western blot., Results: PXR gene transcription could be detected in several hematological malignancy cell lines, and it was significantly higher in K562/A02 cell line, compared with the other cell lines used in this experiment. Low-dose GA could enhance cell growth inhibition rate, increasing the effect of chemotherapy, which may be associated with down-regulation of PXR expression. PXR gene transcription and protein expression in GA and DNR+GA groups decreased as compared with control group and the DNR group, suggesting that low-dose GA can down-regulate PXR gene transcription and protein expression., Conclusion: PXR gene transcription can be detected in several hematological malignancy cell line, which is significantly higher in K562/A02 cell line, as compared with the other cell lines used in this experiment. Low-dose GA can enhance cell growth inhibition rate, increasing the effect of chemotherapy, which may be associated with down-regulation of PXR expression.

Objective: To investigate the effects of miR-21 on paclitaxel-resistance in human breast cancer MCF-7/PR and SKBR-3/PR cells., Methods: Paclitaxel-resistant human breast cancer cell lines MCF-7/PR and SKBR-3/PR were established by stepwise selection in increasing concentration of paclitaxel. Cellular morphology, mRNA and protein level of MDR1, BCRP and MRP1 in MCF-7/PR and SKBR-3/PR cells were determined. The expression of Bax, Bcl-2 and miR-21 in parental and paclitaxel-resistant cells was detected by RT-PCR and Western blotting. The synthetic miR-21 inhibitor or miR-21 mimic were transfected into MCF-7/PR, SKBR-3/PR and MCF-7, SKBR-3 cells with Lipofectamine 2000. The miR-21 levels were determined by RT-PCR, and P-gp, Bcl-2 and Bax protein levels were examined by Western blotting. MTT assay was used to measure the cell viability, and flow cytometry was performed to analyze the cell cycle and apoptosis., Results: The levels of MDR1, BCRP, MRP1, Bcl-2/Bax and miR-21 in MCF-7/PR and SKBR-3/PR cells were significantly higher than those in MCF-7 and SKBR-3 cells. The protein levels of P-gp, Bcl-2 were up-regulated, and Bax was down-regulated compared with parental cells. MiR-21 was significantly down-regulated after miR-21 inhibitor was transfected; and the levels of MDR1, BCRP, MRP1 and Bcl-2/Bax (P <0.05) were also down-regulated. MiR-21 inhibitors significantly suppressed G0/G1 transition of the cell cycle, and induced cell apoptosis in MCF-7/PR and SKBR-3/PR cells. MTT results showed that miR-21 inhibitors induced sensitivity of MCF-7/PR and SKBR-3/PR cells to paclitaxel. And miR-21 mimic can increase the expression of MDR1, Bcl-2/Bax and change cell morphology from parental cells to resistant cells., Results: The established MCF-7/PR and SKBR-3/PR breast cancer cells show typical multidrug resistance characteristics, which can be used as the model for drug resistance study. Down-regulated miR-21 expression in MCF-7/PR and SKBR-3/PR breast cancer cells can enhance cell sensitivity to paclitaxel.

Objective: To investigate the role of RLIP76 in regulating multi-drug resistance in small cell lung cancer (SCLC), and to analyze the relationship between its expression and prognosis., Methods: The expressions of RLIP76 protein and gene were detected by Western blotting and real-time PCR (RT-PCR) in both the chemosensitive SCLC H69 cell line and chemoresistant H69AR cell line, respectively. siRNA was transfected into the H69AR cells to inhibit RLIP76 expression, and eGFP-RLIP76 was transfected into the H69 cells to enhance RLIP76 expression. The drug-sensitivity of cells to chemotherapeutic drugs (ADM, DDP, VP-16) were detected by CCK8 assay. The expression of RLIP76 in the SCLC tissues was detected by immunohistochemistry. The relationship of RLIP76 expression with clinicopathological features and prognosis of the patients was analyzed., Results: The expression of RLIP76 in H69AR cells was 13.675 ± 0.983, significantly higher than 1.074 ± 0.107 in the H69 cells (P < 0.01). The drug-sensitivities of H69AR cells to chemotherapeutic drugs were significantly increased when the expression of RLIP76 was down-regulated (P< 0.001). The sensitivities of H69 cells to chemotherapeutic drugs ADM, DDP and VP-16 were significantly decreased after transfection with eGFP-RLIP76 up-regulating the RLIP76 expression (P = 0.003). The positive expression rates were 61.3% and 9.4% in the SCLC tumor tissues and para-cancerous tissues, respectively (P < 0.01). The expression of RLIP76 was significantly correlated with clinical stage, chemosensitivity and overall survival of the SCLC patients (P < 0.05)., Conclusions: Our results suggest that RLIP76 is involved in the regulation of small cell lung cancer multidrug resistance. RLIP76 may serve as a potential target gene to evaluate the chemosensitivity and clinical prognostic for small cell lung cancer.

Objective: To investigate the expressions of extracellular signal-regulated kinase (ERK) and the BH3-only subgroup of Bcl-2 related proteins (Bim) in multidrug-resistant hepatocellular carcinoma (HCC) cells and their association with drug resistance in the cells., Methods: The multdrug-resistant HepG-2 cell line was established by treatment with gradually increasing doses of ADM. CCK-8 assay was used to determine the drug sensitivity of the cells, and the expressions of MRP-1, P-gp, ERK1, ERK2, ERK5, and Bim were detected with Western blot. Bim mRNA expression level was measured using quantitative real-time PCR., Results: The drug resistance indices to ADM, 5-FU and CDDP was 6.8, 4.10, and 4.5 in HepG-2/ADM cells, respectively. The drug-resistantcells showed marked up-regulation of MRP-1, P-gp, ERK1, ERK2 and ERK5 with down-regulated phosphorylated ERK2 protein expression but no significant changes in phosphorylated ERK1 protein expression to result in a decreased ratio of P-ERK1/2 and P-ERK1/2. Bim mRNA and protein expressions were both decreased in HepG-2/ADM cells., Conclusion: ERK and Bim are related to multidrug resistance in HepG-2/ADM cells.

Objective: To explore the reversal effect of (- )-5-N-acetylardeemin on adriamycin resistance in multidrug-resistant cancer cells including human breast cancer cells MCF-7/Adr and human non-small cell lung cancer cells A549/Adr in vitro., Methods: The multidrug-resistant cancer cells MCF-7/Adr, A549/Adr and their respective parental cells were treated with different concentrations of (- )-5-N-acetylardeemin and adriamycin individually or in combination. Cell death was detected based on the release of lactate dehydrogenase (LDH) using a cytotoxicity detection kit. Intracellular accumulation of adriamycin was measured by the detection of fluorescence intensity of cell lysates using microplate reader. The expression of P-glycoprotein (P-gp) was evaluated by Western blot., Results: (-)-5-N-acetylardeemin significantly reversed the adriamycin resistance in MCF-7/Adr and A549/ Adr in a dose-dependent manner, and the reversal folds were 10. 8 in MCF-7/Adr cells and 20.1 in A549/Adr cells with the treatment of 10 μmol/L (-)-5-N acetylardeemin. (- )-5-N-acetylardeemin also enhanced the sensitivity of parental MCF-7 and A549 cells to adriamycin. The fluorescence intensity in both MCF-7/Adr and A549/Adr cells, which reflected the intracellular accumulation of adriamycin, were significantly enhanced by ( -)5-N- acetylardeemin in a dose-dependent manner. The expressions of P-gp in MCF-7/Adr and A549/Adr cells were significantly inhibited by (- )-5-N-acetylardeemin., Conclusion: (- )5-N-acetylardeemin could reverse the multidrug resistance in cancer cells through inhibiting the expression of P-gp and enhancing the intracellular accumulation of cytotoxic drug.

Objective: To investigate the role of wild-type p53-induced gene 1 (WIG-1) on the regulation of multi-drug resistance in small cell lung cancer., Methods: The expressions of WIG-1 protein and gene were detected by Western blot and real-time PCR (RT-PCR) in both the drug-sensitive H69 and drug-resistant H69AR cell lines, respectively. Meanwhile, the differential expression of WIG-1 was also detected in peripheral blood samples of responders and non-responder patients. Furthermore, the WIG-1 expression was inhibited by siRNA in H69AR cells, then the drug-sensitivities of H69AR cells to chemotherapy agents such as ADM, DDP, VP-16 were detected by CCK8 assay, and apoptosis rate was detected by flow cytometry. The possible association of WIG-1 with clinical parameters was evaluated., Results: The expression of WIG-1 was significantly increased in H69AR cells (5.965 ± 0.890) than that in the H69 cells (1.023 ± 0.127) (P = 0.007). The expression of WIG-1 was significantly increased in the non-responder patients (4.169 ± 0. 970) than in the H69 cells and responders (1.673 ± 0.127) (P < 0.001). The drug-sensitivities of H69AR cells to chemotherapeutic drugs were increased when the expression of the WIG-1 was down-regulated. The apoptosis rate was significantly decreased in the H69AR cells (1.037 ± 0.049)% compared with that in the H69 cells [(7.963 ± 0.097)%, (P < 0.01)]. The apoptosis rate was increased in the H69AR-Si-WIG-1 cells (20.915 ± 0.890)% than that of (1.037 ± 0.049)% in the H69AR and H69AR-NC group (2.025 ± 0.097)% (P < 0.01). The expression of WIG-1 was not significantly associated with gender, and age (P > 0.05), but significantly correlated with chemosensitivity, overall survival and clinical stage (P < 0.001 for all)., Conclusions: Our results suggest that WIG-1 is involved in the regulation of the multidrug resistance mechanism in small cell lung cancer. Selective silencing of the WIG-1 gene may reverse the multidrug resistance of SCLC via increasing cell apoptosis.

Objective: To investigate the genotype of staphylococcal chromosomal cassette mec (SCCmec) in methicillin-resistant Staphylococcus aureus (MRSA) isolated from burn wards and its current status of drug resistance., Methods: One hundred and seventy-nine strains of Staphylococcus aureus were isolated from wound excretion, blood, and sputum samples of patients that were admitted to ICU or public wards of our Department of Burns and Plastic Surgery from September 2012 to September 2013. Among them, 68 strains were from ICU and 111 strains from public wards. The MRSA phenotype of Staphylococcus aureus was detected with cefoxitin K-B disk diffusion method, and the isolation rates of MRSA in ICU and public wards were compared. Genotyping of SCCmec was performed by PCR in strains of MRSA. In the meantime, the identification result of MRSA by K-B method was verified through detecting methicillin-resistant determinant mecA. The antimicrobial resistance of MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) to 23 kinds of commonly used antibiotics in clinic were detected by K-B disk diffusion method. Except for the antibiotics to which the resistant rates of MRSA were 100.0% or 0, the resistant rates of SCCmecIII MRSA and non-SCCmec III MRSA to the rest of antibiotics were compared. Data were processed with Pearson chi-square test or corrected chi-square test., Results: One hundred and forty-eight strains out of the 179 Staphylococcus aureus were identified as MRSA (accounting for 82.7%), among which 62 were originated from ICU and 86 from public wards. The rest 31 strains of Staphylococcus aureus were MSSA, accounting for 17.3%. The percentage of MRSA in the isolated Staphylococcus aureus was 91.2% (62/68) in ICU, which was significantly higher than that in the public wards [77.5% (86/111), χ2 = 5.526, P = 0.019]. PCR detection showed that the 148 strains of MRSA harbored the mecA gene, out of which 106 strains were SCCmec III positive, accounting for 71.6%. The percentages of SCCmec III type MRSA in MRSA isolated from ICU and public wards were respectively 72.6% (45/62) and 70.9% (61/86), showing no statistically significant difference (χ2 = 0.048, P = 0.826). The 148 strains of MRSA were 100.0% resistant to a total of 8 kinds of antibiotics including penicillin and cephalosporins, but it was 0 for vancomycin, teicoplanin, linezolid, tigecycline, nitrofurantoin, and quinupristin/dalfopristin. Except for the 6 kinds of antibiotics to which the resistant rates of MRSA and MSSA were 0, resistant rates of MRSA to the remaining 17 kinds of antibiotics were significantly higher than those of MSSA (with χ2 values from 4.091 to 138.546, P < 0.05 or P < 0.01). Resistant rates of the 106 strains of SCCmecIII type MRSA to levofloxacin, ciprofloxacin, rifampicin, tetracycline, erythrocin, lincomycin, gentamicin, clindamycin were respectively 56.6% (60/106), 85.8% (91/106), 89.6% (95/106), 86.8% (92/106), 84.9% (90/106), 78.3% (83/106), 92.5% (98/106), 74.5% (79/106), and they were significantly higher than those of the 42 strains of non-SCCmec III type MRSA [33.3% (14/42), 61.9% (26/42), 71.4% (30/42), 66.7% (28/42), 69.0% (29/42), 57.1% (24/42), 71.4% (30/42), 52.4% (22/42), with χ2 values from 4.801 to 11.377, P < 0.05 or P < 0.01]., Conclusions: Isolation rate of MRSA from burn wards in our hospital is high, and drug resistance status of this strain against antibiotics is very serious. SCCmec III is the major genotype of the isolated MRSA, but no strains resistant to the glycopeptide antibiotics are found.

Non-Hodgkin's lymphoma (NHL) is a malignant tumor originated in lymphatic hematopoietic tissue. At present, chemotherapy is the main treatment method of NHL, but the chemoresistance is still an important reason for NHL treatment failure. The mechanism of NHL multidrug resistance (MDR) is complex, involving a variety of singnal pathways, in which mutation in the genetic level of the key genes can result in tumor cell resistance phenomenon. MicroRNA are small non-coding RNA that can be widely detected in plants,animal species and viruses. They regulate protein expression by repressing translation mRNA target at the post-transcriptional level, participating in the differentiation and development of tumor cells, as well as the occurrence and development of tumor, the change of the expression level microRNA plays an important role in the genesis and chemoresistance mechanism of NHL. Therefore, the intervening factitiously the expression level of microRNA in NHL through manufacturing antisense oligonucleotide (AMO) or using substitution of microRNA, changing the expression level of their target protein, and combining with the therapy of NHL, there will be an guiding significance in reversing the drug and radiation resistance of NHL, thus improving its poor prognosis. This article reviews the microRNAs closely related with drug and radiation resistance of NHL, and their potential targets. Furthermore, the specific role of these microRNAs in the genesis and chemoresistance mechanism of NHL are deeply elaborated.