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The dysregulation of microRNAs (miRNAs) has been demonstrated to contribute to drug resistance of cancer cells, and sustained nuclear factor (NF)κB activation is also pivotal in tumor resistance to chemotherapy. In the present study, an essential role for miRNA (miR)-20a was identified in the regulation of gastric cancer (GC) chemoresistance. The expression level of miR‑20a was assayed by reverse transcription‑quantitative polymerase chain reaction. Additionally, 3-(4,5-dimethylthiazol-2‑yl)-2,5-diphenyltetrazolium bromide was used to detect the drug‑resistance phenotype changes of cancer cells associated with upregulation or downregulation of miR‑20a. Protein expression levelss were measured by western blotting and immunohistochemistry. Flow cytometry was used to detect cisplatin‑induced apoptosis. It was found that miR‑20a was markedly upregulated in GC plasma and tissue samples. Additionally, miR‑20a was upregulated in GC plasma and tissues from patients with cisplatin (DDP) resistance, and in the DPP‑resistant gastric cancer cell line (SGC7901/DDP). The expression of miR‑20a was inversely correlated with the expression of cylindromatosis (CYLD). Subsequently, the assessment of luciferase activity verified that CYLD was a direct target gene of miR‑20a. Treatment with miR‑20a inhibitor increased the protein expression of CYLD, downregulated the expression levels of p65, livin and survivin, and led to a higher proportion of apoptotic cells in the SGC7901/DDP cells. By contrast, ectopic expression of miR‑20a significantly repressed the expression of CYLD, upregulated the expression levels of p65, livin and survivin, and resulted in a decrease in the apoptosis induced by DDP in the SGC7901 cells. Taken together, the results of the present study suggested that miR‑20a directly repressed the expression of CYLD, leading to activation of the NFκB pathway and the downstream targets, livin and survivin, which potentially induced GC chemoresistance. Altering miR‑20a expression may be a potential therapeutic strategy for the treatment of chemoresistance in GC in the future.

Drug resistance of cancer cells can be regulated by the dysregulated miRNAs, and sustained NFκB activation also plays an important role in tumor resistance to chemotherapy. Here, we sought to investigate whether there was a correlation between miR-20a and the NFκB pathway to clarify the effects that miR-20a exerted on gastric cancer (GC) chemoresistance. We found that miR-20a was significantly upregulated in GC plasma and tissue samples. In addition, it was upregulated in GC plasma and tissues from patients with cisplatin-resistant gastric cancer cell line SGC7901/cisplatin (DDP). And the upregulation of miR-20a was concurrent with the downregulation of NFKBIB (also known as IκBβ) as well as upregulation of p65, livin, and survivin. The luciferase activity suggested that NFKBIB was the direct target gene of miR-20a. Transfection of miR-20a inhibitor could increase NFKBIB level; downregulate the expression of p65, livin, and survivin; and lead to a higher proportion of apoptotic cells in SGC7901/DDP cells. Conversely, ectopic expression of miR-20a dramatically decreased the expression of NFKBIB; increased the expression of p65, livin, and survivin; and resulted in a decrease in the apoptosis induced by DDP in SGC7901 cells. Taken together, our findings suggested that miR-20a could promote activation of the NFκB pathway and downstream targets livin and survivin by targeting NFKBIB, which potentially contributed to GC chemoresistance.

microRNAs (miRNAs) are short non-coding RNA molecules, which post-transcriptionally regulate genes expression and play crucial roles in diverse biological processes, such as development, differentiation, apoptosis, and proliferation. Here, we investigated the possible role of miRNAs in the development of drug resistance in human lung cancer cell line. We found that miR-135a/b were downregulated while MCL1 was upregulated in A549/CDDP (cisplatin) cells, compared with the parental A549 cells. In vitro drug sensitivity assay demonstrated that overexpression of miR-135a/b sensitized A549/CDDP cells to cisplatin. The luciferase activity of MCL1 3'-untranslated region-based reporter constructed in A549/CDDP cells suggested that MCL1 was the direct target gene of miR-135a/b. Enforced miR-135a/b expression reduced MCL1 protein level and sensitized A549/CDDP cells to CDDP-induced apoptosis. Taken together, our findings first suggested that hsa-miR-135a/b could play a role in the development of CDDP resistance in lung cancer cell line at least in part by modulation of apoptosis via targeting MCL1.

Drug resistance is one of the leading causes of chemotherapy failure in cancer treatment. MicroRNAs (miRNAs or miRs) are short non-coding RNA molecules that post-transcriptionally regulate gene expression and play a critical role in diverse biological processes. In this study, we report that miR-503 regulates the resistance of non-small cell lung cancer cells to cisplatin. The expression of miR-503 was decreased in the cisplatin-resistant non-small cell lung cancer cells, A549/CDDP, compared with the parental A549 cells. The overexpression of miR-503 sensitized the A549/CDDP cells to cisplatin, whereas the inhibition of miR-503 in the A549 cells increased resistance to cisplatin. Mechanistically, miR-503 specifically targeted Bcl-2, an anti-apoptotic protein upregulated in the A549/CDDP cells. The ectopic expression of miR-503 reduced the Bcl-2 protein level and sensitized the A549/CDDP cells to cisplatin-induced apoptosis. Taken together, our results suggest that miR-503 regulates cell apoptosis, at least in part by targeting Bcl-2, and thus modulates the resistance of non-small cell lung cancer cells to cisplatin.

It has been found that the epigenetic silence of tumor suppressor genes induced by overexpression of histone deacetylases (HDACs) plays an important role in carcinogenesis. HDAC inhibitors (HDACi) that block the activity of specific HDACs have emerged as the accessory therapeutic agents for multiple human cancers. To better understand the effects of HDACi in cancer treatment, we carried out a review based on 30 published clinical trials to determine whether HDACi will benefit patients with solid tumors. Information of complete response, partial response, stable disease, objective responses and objective response rate was collected to assess clinical outcomes. A lack of therapeutic effects was observed when HDACi was used as a single agent. However, when HDACi treatment was combined with other agents, it appeared to increase the anti-tumor activity. High-quality studies are required to better understand the clinical effects of HDACi.

Background: Patients with advanced or metastatic non-small cell lung cancer (NSCLC) can develop acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) erlotinib and gefitinib. Here, we report the successful treatment with alternating chemotherapy and TKIs of two cases of advanced NSCLC who developed resistance to TKI., Case Presentation: Two patients with advanced or metastatic NSCLC were treated with palliative chemotherapy followed by erlotinib/gefitinib. When TKI therapy failed, two cycles of chemotherapy were provided, which were followed by re-challenge with erlotinib or gefitinib., Conclusion: NSCLC patients with acquired TKI resistance should be managed aggressively whenever possible. Subsequent chemotherapy and target treatment is one of the reasonable choices for those with an initial dramatic clinical response with erlotinib/gefitinib treatment. Further studies are warranted to substantiate the association of erlotinib /gefitinib treatment with the efficacy of NSCLC patients with acquired TKI failure.

Objective: We sought to determine whether paeoniflorin enhances 5-fluorouracil-induced apoptosis in human gastric carcinoma cells, and, if so, to determine the relationship between this apoptosis and NF-kappaB activation., Methods: Paeoniflorin was diluted to different concentrations and added to gastric carcinoma cells (SGC-7901) at different times. Western blot was used to test the expression of NF-kappaB in nuclear and I kappaB alpha, p-I kappaB alpha, IKK alpha in cytoplasm. Further, the intranuclear expression of NF-kappaB was confirmed by ELISA assay. The impact of paeoniflorin and 5-fluorouracil on cell apoptosis of gastric carcinoma cells was estimated by flow cytometry., Results: Paeoniflorin revealed dramatic inhibition of NF-kappaB activity in the nuclei of the cells. The inhibition pattern of NF-kappaB was exhibited in a time- and dose-dependent manner, which was confirmed by Western blot and ELISA. Decreased nuclear translocation of NF-kappaB induced by paeoniflorin was found by preventing I kappaB alpha phosphorylation. Moreover, 5-fluorouracil-induced cell apoptosis was promoted by paeoniflorin in gastric carcinoma cells., Conclusions: Paeoniflorin can inhibit NF-kappaB activity of SGC-7901 cells, and enhance 5-fluorouracil-induced apoptosis of gastric carcinoma cells.

Purpose: Anlotinib is a novel oral multi-targeted receptor tyrosine kinase inhibitor, which selectively inhibits VEGFR2/3, FGFR1-4, PDGFR α/β, c-kit, and Ret. It shows antitumor effect in patients with advanced refractory solid tumors. The detailed absorption, metabolism, and excretion pathways of anlotinib have not yet been fully investigated.Methods: Six male patients were enrolled and divided into two groups. Group A (containing two patients) received 14.15 mg/80 µCi/subject [14C]-anlotinib hydrochloride. Group B (containing four patients) received 14.15 mg/120 µCi/subject [14C]-anlotinib hydrochloride. The blood, urine, and feces of all the six patients after orally administration of [14C]-anlotinib were collected. The absorption, metabolism, and excretion of [14C]-anlotinib were investigated, and the efficacy and safety of anlotinib were evaluated.Results: In plasma, the average time to peak concentration (Tmax) of total radioactivity was 4.42 h and the average peak concentration (Cmax) of total radioactivity was 18.80 ng Eq./g. The average values of AUC0-last, AUC0-∞, and MRT0-t were 4071 h.ng Eq./g, 13,555 h.ng Eq./g, and 125 h, respectively. The average recovery of total radioactivity (TRA) in urine and feces was 62.03%, accounting for 48.52% and 13.51% in feces and urine of the total dosage, respectively. The parent drug, a carboxylic metabolite (M30), and mono-oxidation products (M46/M66) were major drug-related components in human plasma. Oxidative metabolism played the major role in drug clearance in human. The major metabolic pathways include oxidative deamination to M2, mono-oxidation to M1, and the formation of M30. Adverse events occurred in five patients and severe adverse events (SAE) occurred in one. Tumor response were evaluated as stable disease (SD) in three, partial response (PR) in one, and progressive disease (PD) in one of the patients, respectively.Conclusions: Anlotinib had a good pharmacokinetic profile with rapid absorption, long half-life, and extensive hepatic metabolism. The adverse events and efficacy were as expected. [ABSTRACT FROM AUTHOR]

Purpose: MicroRNAs (miRNAs) are short non-coding RNA molecules, which post-transcriptionally regulate genes expression and play crucial roles in diverse biological processes. Recent studies have shown that dysregulation of miRNAs might modulate the resistance of cancer cells to anti-cancer drugs, yet the modulation mechanism is not fully understood. We aimed to investigate the possible role of miRNAs in the development of multidrug resistance (MDR) in human gastric and lung cancer cell lines. Methods: miRNA Quantitative real-time PCR was used to detect the different miRNA expression levels between drug resistant and parental cancer cells. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to test the drug-resistant phenotype changes in cancer cells via over or downregulation of miRNAs. Dual-luciferase activity assay was used to verify the target genes of miRNAs. Western blot analysis and apoptosis assay were used to elucidate the mechanism of miRNAs on modulating drug resistance in cancer cells. Results: miR-200bc/429 cluster was downregulated, while BCL2 and XIAP were upregulated in both MDR SGC7901/VCR (vincristine) and A549/CDDP (cisplatin) cells, compared with the parental SGC7901 and A549 cells, respectively. Overexpression of miR-200bc/429 cluster sensitized SGC7901/VCR and A549/CDDP cells to anti-cancer drugs, respectively. Both BCL2 and XIAP 3′-UTR reporters constructed in MDR cells suggested that BCL2 and XIAP were the common target genes of the miR-200bc/429 cluster. Enforced miR-200bc/429 cluster expression reduced BCL2 and XIAP protein level and sensitized both MDR cells to VCR-induced and CDDP-induced apoptosis, respectively. Conclusions: Our findings first suggest that miR-200bc/429 cluster could play a role in the development of MDR in both gastric and lung cancer cell lines, at least in part by modulation of apoptosis via targeting BCL2 and XIAP. [ABSTRACT FROM AUTHOR]