Search

MicroRNAs (miRNAs) are known to be important in a variety of cancer types. The specific expression and roles of miR-520f-3p in the context of gastric cancer (GC), however, remains unknown. Herein we determined miR-520f-3p expression to be significantly reduced in human GC cells compared to cells of the gastric epithelium, with comparable down-regulation also being evident in gastric cancer tissue samples and the low expression of this miRNA was positively correlated with features of more aggressive large tumor size (p = 0.019), depth of invasion (p = 0.008), and distant metastasis (p = 0.037). We further found that lower levels of miR-520f-3p corresponded with poorer GC patient overall (p = 0.003) and disease-free (p = 0.036) survival. When over-expressed in GC cells, miR-520f-3p was able to impair their growth, proliferation, and survival, instead leading to the induction of apoptosis. We further found that miR-520f-3p was able to bind the SOX9 3′-UTR, thereby negatively regulating its expression in GC cells. Consistent with this model, SOX9 and miR-520f-3p expression were negatively correlated with one another in GC tissues. When SOX9 was upregulated, this was also able to abrogate miR-520f-3p-mediated inactivation of Wnt/β-catenin signaling. Together our findings thus suggest that miR-520f-3p can act to suppress GC progression, at least in part via suppressing SOX9 expression and thus disrupting Wnt/β-catenin signaling. Our results thus highlight potential novel therapeutic targets in GC worthy of future investigation. [ABSTRACT FROM AUTHOR]

Background/Aims: Current practical advances in high-throughput data technologies including RNA-sequencing have led to the identification of long non-coding RNAs (lncRNAs) for potential clinical application against bladder urothelial cancer (BLCA). However, most previous studies focused on the clinical value of individual lncRNAs, which has limited the potential for future clinical application. Methods: In this study, RNA-sequencing data of lncRNAs was downloaded from The Cancer Genome Atlas database. Risk score was constructed based on survival-associated lncRNAs identified using differential expression analysis as well as univariate and multivariate Cox proportional hazards regression analysis. Receiver operating characteristic and Kaplan-Meier curve analyses were employed to evaluate the clinical and prognostic value of risk scores. Bioinformatics analyses were used to investigate the potential mechanisms of newly identified lncRNAs. Results: Among 2,127 differentially expressed lncRNAs (DELs), four new lncRNAs (AC145124.1, AC010168.2, MIR200CHG, and AC098613.1) showed valuable prognostic effects in BLCA patients. More importantly, the four-DEL-based risk score had the potential to become an independent marker for the survival status prediction of BLCA patients. Distinct co-expressed genes and signaling pathways were identified when BLCA was categorized into low- and high-risk groups. Furthermore, a protein-coding gene, HIST4H4 was found only 68 bp from the AC010168.2 DEL. HIST4H4 expression level was evidently up-regulated and positively correlated with AC010168.2 in BLCA patients. Conclusion: This in silico investigation pioneers the future investigation of the utility of prognostic lncRNAs for BLCA. [ABSTRACT FROM AUTHOR]

Two iridium (III) polypyridine complexes [Ir(ppy) 2 (BIP)]PF 6 (ppy = 2-phenylpyridine, BIP = 2-biphenyl-1 H -imidazo[4,5-f][1,10]phenanthroline, Ir1), [Ir(piq) 2 (BIP)]PF 6 (piq = 1-phenylisoquinoline, Ir2) and their liposomes Ir1lipo and Ir2lipo were synthesized and characterized. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate cytotoxic activity against several cancer cells (A549, HepG2, SGC-7901, Bel-7402, HeLa) and non-cancer cell (mouse embryonic fibroblast, NIH3T3). The results showed that Ir1lipo displays the high cytotoxicity toward SGC-7901 with IC 50 value of 5.8 ± 0.2 μM, while the complexes have no cytotoxicity toward A549, HepG2, Bel-7402 and HeLa cells. The cell colony demonstrated that the iridium (III) complexes-loaded liposomes can inhibit cell proliferation, induce cell cycle arrest at G0/G1 phase. Moreover, they also cause autophagy, induce a decrease of mitochondrial membrane potential and increase intracellular reactive oxygen species (ROS) content. These results suggest that the complexes encapsulated liposomes Ir1lipo and Ir2lipo inhibit the growth of SGC-7901 cells through a ROS-mediated mitochondrial dysfunction and activating the PI3K (phosphoinositide-3 kinase)/ AKT (protein kinase B) signaling pathways. Two new iridium (III) complexes and their liposomes were synthesized and characterized. The in vitro cytotoxicity was investigated. The complexes show low or no anticancer activity, while the liposomes exhibit high anticancer effect. [Display omitted] • The iridium (III) complexes and their liposomes were synthesized and characterized. • The in vitro cytotoxicity of the complexes and liposomes was studied. • The expression of Bcl (B-cell lymphoma)-2 family proteins were assayed. • The apoptosis, cell cycle arrest and autophagy were investigated. • The uptake was assayed by inductively coupled plasma mass spectrometry (ICP-MS). [ABSTRACT FROM AUTHOR]

Abstract: Design of an efficient site-specific drug delivery system based on degradable functional polymers still remains challenging. In this work, we synthesized and characterized three degradable functional polyesters belonging to the poly(malic acid) family: the poly(benzyl malate) (PMLABe), the poly(ethylene glycol)-b-poly(benzyl malate) (PEG42-b-PMLABe), the biotin-poly(ethylene glycol)-b-poly(benzyl malate) (Biot-PEG62-PMLABe). Starting from these building blocks, we were able to prepare the corresponding well-defined degradable functional nanoparticles whose toxicity was evaluated in vitro on normal and cancer cell lines. Results have evidenced that the prepared nanoparticles did not show any significant cytotoxicity even at high concentrations. A model anti-cancer drug (doxorubicin, Dox) or a fluorescent probe (1,1′-dioctadecyl-3,3,3′,3′-tetramethylindodicarbocyanine, DiD oil) has been encapsulated into PMLABe, PEG42-PMLABe or Biot-PEG62-PMLABe based nanoparticles in order to evaluate, respectively, the in vitro cytotoxicity of Dox-loaded nanoparticles on normal and cancer cell lines and the ligand (biotin) effect on cellular uptake in vitro using mmt 060562 cell line. Dox-loaded PMLABe, PEG42-PMLABe or Biot-PEG62-PMLABe nanoparticles showed an in vitro cytotoxicity similar to that of free Dox. Moreover, the DiD oil loaded Biot-PEG62-PMLABe based nanoparticles showed a better in vitro cellular uptake than ligand-free DiD oil loaded nanoparticles. Both results evidence the great potential of such degradable functional poly(malic acid) derivatives for the design of highly efficient site-specific anti-cancer nanovectors. [Copyright &y& Elsevier]

Abstract: Two new indole diketopiperazines, namely luteoalbusins A–B (1–2), along with eight known ones (3–10), were isolated from the fungus Acrostalagmus luteoalbus SCSIO F457 originated from deep-sea sediment. Their structures were determined by 1D/2D NMR, MS, and CD data analyses. Each of these compounds was evaluated for their cytotoxic activities against SF-268, MCF-7, NCI-H460, and HepG-2 cell lines, and compounds 1–5 showed significant cytotoxicties against all four cancer cell lines. Moreover, new compounds 1 and 2 had more potent cytotoxicity than the other ones and cisplatin. [Copyright &y& Elsevier]

The present study was carried out to investigate the potential of cationic functionalization on imatinib nanocrystals to improve the mucoadhesiveness and, thus, delivery to the lesion of cervicovaginal tumors. Amino-group-functionalized imatinib nanocrystals (NC@PDA-NH2) were prepared with near-spheroid shape, nanoscale size distribution, positive zeta potential, and relatively high drug content with the aid of the polydopamine-coating technique. Efficient interaction between NC@PDA-NH2 and mucin was proven by mucin adsorption which was related to the positive zeta-potential value of NC@PDA-NH2 and the change in the size distribution on mixing of NC@PDA-NH2 and mucin. Cellular uptake, growth inhibition, and apoptosis induction in cervicovaginal cancer-related cells demonstrated the superiority of NC@PDA-NH2 over unmodified nanocrystals. For practical intravaginal administration, NC@PDA-NH2 was dispersed in Pluronic F127-based thermosensitive in situ hydrogel, which showed suitable gelation temperature and sustained-release profiles. In comparison with unmodified nanocrystals, NC@PDA-NH2 exhibited extended residence on ex vivo murine vaginal mucosa, prolonged in vivo intravaginal residence, and enhanced inhibition on the growth of murine orthotopic cervicovaginal model tumors indicated by smaller tumor size, longer median survival time, and more intratumor apoptosis with negligible mucosal toxicity. In conclusion, cationic functionalization endowed NC@PDA-NH2 significant mucoadhesiveness and, thus, good potential against cervicovaginal cancer via intravaginal administration. [ABSTRACT FROM AUTHOR]

Background： Aloe-emodin, an anthraquinone present in aloe latex, has been shown to have anti-proliferative properties in cervical cancer disease, all cases of which are almost caused by human papillomavirus (HPV), with the products of E6/E7. It is suggested that aloe-emodin may play an important role in HPV-induced cervical cancer cells. Methods： Hela and SiHa cells were treated with various concentrations of aloe-emodin. MTT assay and flow cytometry were used to identify the cell growth and apoptosis. The expressions of HPV E6, E7 and GLUT1 (glucose transporter-1) were detected by real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot (WB). The glucose uptake, lactate production and ATP production in HeLa and SiHa cells were also investigated. Result： The results indicate that aloe-emodin promoted the apoptosis of HeLa and SiHa cells and decreased the expressions of HPV-related protein E6 and E7. Furthermore, aloe-emodin inhibited glucose metabolism by reducing GLUT1 expression. Overexpression of GLUT1 significantly weakened the apoptosis induced by aloe-emodin in HeLa cells. Conclusion： In this study, we found that aloe-emodin induce apoptosis of cervical cancer cells, which was associated with HPV E6 and E7 and glucose metabolism. [ABSTRACT FROM AUTHOR]

Abstract: A series of mansonone F (MF) derivatives were designed and synthesized. These compounds were found to be strong inhibitors for topoisomerases, with much more significant inhibition for topoisomerase II rather than topoisomerase I. The best inhibitor showed 20 times stronger anti-topoisomerase II activity than a positive control Etoposide. The cytotoxic activity of these MF derivatives was evaluated against human cancer cell lines CNE-2 and Glc-82, which showed that these compounds were potent antitumor agents. The structure–activity relationships (SARs) study revealed that o-quinone group and pyran ring are important for their cytotoxic activity. [Copyright &y& Elsevier]

Mitochondria have a crucial role in regulating energy metabolism and their dysfunction has been linked to tumorigenesis. Cancer diagnosis and intervention have a great interest in the development of new agents that target biomolecules within mitochondria. However, monitoring and modulating mitochondria RNA (mtRNA), an essential component in mitochondria, in cells is challenging due to limited functional research and the absence of targeting agents. In this study, we designed and synthesized a fluorescent quinolinium derivative, QUCO-1, which actively lit up with mtRNA in both normal and cancer cells in vitro. Additionally, we evaluated the function of QUCO-1 as an mtRNA ligand and found that it effectively induced severe mitochondrial dysfunction and OXPHOS inhibition in RKO colorectal cancer cells. Treatment with QUCO-1 resulted in apoptosis, cell cycle blockage at the G2/M phase, and the effective inhibition of cell proliferation. Our findings suggest that QUCO-1 has great potential as a promising probe and therapeutic agent for mtRNA, with the potential for treating colorectal cancer. [ABSTRACT FROM AUTHOR]

Didymin is a dietary flavonoid that first found in citrus fruits, and possesses antioxidant properties. Our preliminary experiments first discovered that didymin was able to sensitize the resistant cancer cells against chemotherapeutics and combat multidrug resistance. However, its poor aqueous solubility and resultant low bioavailability limit its potentials as an adjuvant phytochemical drug for chemotherapy. Thus, this study prepared the inclusion complex of didymin with β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin to improve its bioavailability and then evaluate their chemosensitization effects. The didymin inclusion complexes formulation was prepared and their host-guest structure was characterized by FT-IR, PXRD, DSC, and SEM techniques. In vitro/in vivo results demonstrated that didymin inclusion complex enhanced its water solubility and orally bioavailability. Furthermore, didymin inclusion complex exerted considerable chemosensitivity potency, and improve the anti-tumor effects of chemotherapeutics in vivo. Therefore, didymin inclusion complex could provide a safe, effective, economical, and adjuvant drug for future treatment of chemoresistant cancers. [ABSTRACT FROM AUTHOR]

A novel series of cyclin-dependent kinases (CDKs) inhibitors, which play critical roles in the cell cycle control and regulation of cell transcription, were synthesised. A systematic study of enzymatic and cellular assays led to the identification of compound X22 with a nanomolar potency against CDK4 and CDK9 and potent antiproliferative activities against a panel of tumour cell lines. X22 could induce cell cycle arrest and cell apoptosis in cancer cell lines. X22 dose-dependently inhibits signalling pathways downstream of CDKs in cancer cells. In vivo antitumor activity assays, oral administration of X22 led to significant tumour regression in mouse model without obvious toxicity. Superior anti-cancer efficacy in vitro and in vivo of X22 demonstrated combined depletion of cell cycle and transcriptional CDK all contributed to antitumor activity. Taken together, concomitant inhibition of cell cycle and transcriptional CDK activities provided valuable guide for further structural optimisation. [ABSTRACT FROM AUTHOR]

Introduction: Dynamin 3 (DNM3) is a large GTPase that possesses mechanochemical properties and has been shown to be involved in malignancies. However, most studies about DNM3 are observational, and knowledge of the precise molecular mechanism of DNM3 remains limited. Materials and methods: We constructed a PCDH-CMV-MCS-EF1a-GFP-Puro-DNM3 recombinant eukaryotic expression vector, which was then transfected into SW620 and LoVo cells. One cell line was divided into three groups. DNM3 mRNA and protein expression was analyzed by quantitative real-time PCR and Western blot assay. To investigate DNM3 biological activity in colon cancer SW620 and LoVo cell line, we performed cell proliferation, transwell migration, and invasion assay. Matrix metalloproteinase (MMP)-2 and MMP-9 protein expressions were detected by Western blot. Result: We successfully constructed a PCDH-CMV-MCS-EF1a-GFP-Puro-DNM3 recombinant eukaryotic expression vector, and stable DNM3 expression was observed in SW620 and LoVo cell lines. The vector overexpressing DNM3 inhibited the proliferation, weak invasion, and migration ability of colon cancer SW620 and LoVo cells relative to those in the control group (all P,0.001). DNM3 downregulated the protein expression of MMP-2 and MMP-9. Conclusion: DNM3 may weaken the malignant behavior of colon cancer and may have promoted the invasion and migration of colon cancer by regulating the expression of MMP-2 and MMP-9. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various acridone derivatives were synthesized and evaluated for anticancer activity. • C4 exhibited potent activity against Hep-G2 cells with IC 50 value of 6.29 ± 0.93 μM. • C4 could specifically bind to and destabilize Kras gene promoter i-motif structure. • C4 down-regulated Kras gene expression possibly through its promoter i-motif. • C4 induced cell apoptosis possibly related to its effect on mitochondrial dysfunction. Two series of novel acridone derivatives were designed and synthesized, with their anticancer activity evaluated. Most of these compounds showed potent antiproliferative activity against cancer cell lines. Among them, compound C4 with dual 1,2,3-triazol moieties exhibited the most potent activity against Hep-G2 cells with IC 50 value determined to be 6.29 ± 0.93 μM. Subsequent experiments showed that C4 could bind to and destabilize Kras gene promoter i-motif structure without significant interaction with its corresponding G-quadruplex. C4 could down-regulate Kras expression in Hep-G2 cells, possibly due to its interaction with the Kras i-motif. Further cellular studies indicated that C4 could induce apoptosis of Hep-G2 cells, possibly related to its effect on mitochondrial dysfunction. These results indicated that C4 could be further developed as a promising anticancer agent. [ABSTRACT FROM AUTHOR]

Novel topoisomerase II (Topo II) inhibitors have gained considerable interest for the development of anticancer agents. In this study, a series of carbazole derivatives containing chalcone analogs (CDCAs) were synthesized and investigated for their Topo II inhibition and cytotoxic activities. The results from Topo II mediated DNA relaxation assay showed that CDCAs could significantly inhibit the activity of Topo II, and the structure-activity relationship indicated the halogen substituent in phenyl ring play an important role in the activity. Further mechanism studies revealed that CDCAs function as non-intercalative Topo II catalytic inhibitors. Moreover, some CDCAs showed micromolar cytotoxic activities. The most potent compound 3h exhibited notable growth inhibition against four human cancer cell lines. Flow cytometric analysis revealed that compounds 3d and 3h arrested the HL-60 cells in sub G1 phase by induction of apoptosis. It was further confirmed by Annexin-V-FITC binding assay. Western blot analysis revealed that compound 3h induces apoptosis likely through the activation of caspase proteins. [ABSTRACT FROM AUTHOR]

Background Telomeric repeat–containing RNA (TERRA) is a large non-coding RNA in mammalian cells, which forms an integral component of telomeric heterochromatin. TERRA can bind to an allosteric site of telomeric repeat factor 2 (TRF2), a key component of Shelterin that protect chromosome termini. Both TERRA and TRF2 have been recognized as promising new therapeutic targets for cancer treatment. Methods Our methods include FRET assay, SPR, CD, microscale thermophoresis (MST), enzyme-linked immunosorbent assay (ELISA), chromatin immunoprecipitation (ChIP), colony formation assays, Western blot, immunofluorescence, cell cycle arrest and apoptosis detection, and xCELLigence real-time cell analysis (RTCA). Results In our routine screening of small molecule libraries, we found that a Quindoline derivative, CK1-14 could bind to and stabilize TERRA G-quadruplex structure, which could bind more tightly with an allosteric site of a telomeric binding protein TRF2, resulting in dissociation of TRF2 from telomeric DNA. Further in cellular studies indicated that the above effect of CK1-14 on TERRA G-quadruplex could activate DNA-damage response and cause cell cycle arrest, resulting in inhibition of U2OS cell proliferation and causing cell apoptosis. Conclusions Our mechanistic studies indicated that interaction of CK1-14 with TERRA induces telomeric DNA-damage response in U2OS cancer cells through inhibition of TRF2. CK1-14 could be further developed as a promising lead compound targeting telomere for cancer treatment. General significance Our present study provides the first evidence that allosteric modulation of TRF2 by TERRA G-quadruplex with a binding ligand could become a promising new strategy for cancer treatment especially for ALT tumor cells. [ABSTRACT FROM AUTHOR]

A series of chromeno[4,3- d]isoxazolo[5,4- b]pyridin-6-one derivatives were easily and efficiently synthesized by the reaction of 3-acyl-2 H-chromen-2-ones with isoxazol-5-amine in . Some synthesized compounds were evaluated for their antiproliferative properties in vitro against cancer cells, and these compounds were found to have some activities. [ABSTRACT FROM AUTHOR]

Background: Rupture of hepatocellular carcinoma (HCC) releases tumor cells and furthers peritoneal metastasis. The present study investigated the killing effects of distilled water (DW) on HCC cells and the clinical outcomes of patients undergoing liver resection with DW lavage for spontaneously ruptured HCC. Materials and Methods: Human HCC cells (BEL-7402, SMMC7721) were treated with DW, the morphological changes observed, and cell viability measured. DW-treated HCC cells were also injected intraperitoneally into nude mice, and the formation of tumor nodules and overall survival (OS) measured. The clinicopathological data of 141 consecutive patients undergoing liver resection for spontaneously ruptured HCC during 1998-2011 were retrospectively reviewed. Results: Fifteen minutes of DW exposure caused complete cell lysis of HCC cells in vitro and completely prevented tumor formation and prolonged survival time in nude mice. Among the 141 patients, the 1-, 3-, and 5-year disease-free survival (DFS) and OS rates in patients administered DW lavage during surgery were 68.9, 24.6, and 6.6 %, respectively, and 95.1, 65.1, and 40 %, respectively, which were significantly higher than those in patients who did not ( P < 0.05). DW lavage was an independent predictor of recurrence (odds ratio (OR), 0.34; 95 % confidence interval (CI), 0.23-0.51; P < 0.001) and OS (OR, 0.35; 95 % CI, 0.23-0.53; P < 0.001). Conclusions: Fifteen minutes of DW lavage can effectively kill HCC cells in vitro and prevent tumor formation in vivo. DW lavage significantly improves long-term outcomes in patients undergoing liver resection for spontaneously ruptured HCC and could be administered intra-operatively when tumor cell liberation is suspected. [ABSTRACT FROM AUTHOR]

Brain tumor initiating cells (BTICs) co-opt the neuronal high affinity glucose transporter, GLUT3, to withstand metabolic stress. We investigated another mechanism critical to brain metabolism, mitochondrial morphology, in BTICs. BTIC mitochondria were fragmented relative to non-BTIC tumor cell mitochondria, suggesting that BTICs increase mitochondrial fission. The essential mediator of mitochondrial fission, dynamin-related protein 1 (DRP1), showed activating phosphorylation in BTICs and inhibitory phosphorylation in non-BTIC tumor cells. Targeting DRP1 using RNA interference or pharmacologic inhibition induced BTIC apoptosis and inhibited tumor growth. Downstream, DRP1 activity regulated the essential metabolic stress sensor, AMP-activated protein kinase (AMPK), and targeting AMPK rescued the effects of DRP1 disruption. Cyclin-dependent kinase 5 (CDK5) phosphorylated DRP1 to increase its activity in BTICs, whereas Ca2+-calmodulin-dependent protein kinase 2 (CAMK2) inhibited DRP1 in non-BTIC tumor cells, suggesting that tumor cell differentiation induces a regulatory switch in mitochondrial morphology. DRP1 activation correlated with poor prognosis in glioblastoma, suggesting that mitochondrial dynamics may represent a therapeutic target for BTICs. [ABSTRACT FROM AUTHOR]

Abstract: A series of 1,8-dipyrazolcarbazole (DPC) derivatives (6a–6d, 7a–7d) designed as G-quadruplex ligands have been synthesized and characterized. The FRET-melting and SPR results showed that the DPC derivatives could well recognize G-quadruplex with strong discrimination against the duplex DNA. In addition, the DPC derivatives showed much stronger stabilization activities and binding affinities for c-myc G-quadruplex rather than telomeric G-quadruplex. Therefore, their interactions with c-myc G-quadruplex were further explored by means of CD spectroscopy, PCR-stop assay, and molecular modeling. In cellular studies, all compounds showed strong cytotoxicity against cancer cells, while weak cytotoxicity towards normal cells. RT-PCR assay showed that compound 7b could down-regulate c-myc gene expression in Ramos cell line, while had no effect on c-myc expression in CA46 cell line with NHE III1 element removed, indicating its effective binding with G-quadruplex on c-myc oncogene in vivo. [Copyright &y& Elsevier]

Abstract: The protein POT1 plays an important role in telomere protection, which is related with telomere elongation and cell immortality. The protein has been recognized as a promising drug target for cancer treatment. In the present study, we cloned, overexpressed in Escherichia coli for the first time, and purified recombinant human POT1. The protein was proved to be active through filter binding assay, FRET and CD experiments. In the initial screening for protein binding ligands using SPR, compound Sysu-00692 was found to bind well with the POT1, which was confirmed with EMSA. Its in vivo activity study showed that compound Sysu-00692 could interfere with the binding between human POT1 and the telomeric DNA through chromatin immunoprecipitation. Besides, the compound showed mild inhibition on telomerase and cell proliferation. As we know, compound Sysu-00692 is the first reported POT1-binding ligand, which could serve as a lead compound for further improvement. This work offered a potentially new approach for drug design for the treatment of cancers. [Copyright &y& Elsevier]

Summary: Glioblastomas display cellular hierarchies containing tumor-propagating glioblastoma stem cells (GSCs). STAT3 is a critical signaling node in GSC maintenance but molecular mechanisms underlying STAT3 activation in GSCs are poorly defined. Here we demonstrate that the bone marrow X-linked (BMX) nonreceptor tyrosine kinase activates STAT3 signaling to maintain self-renewal and tumorigenic potential of GSCs. BMX is differentially expressed in GSCs relative to nonstem cancer cells and neural progenitors. BMX knockdown potently inhibited STAT3 activation, expression of GSC transcription factors, and growth of GSC-derived intracranial tumors. Constitutively active STAT3 rescued the effects of BMX downregulation, supporting that BMX signals through STAT3 in GSCs. These data demonstrate that BMX represents a GSC therapeutic target and reinforces the importance of STAT3 signaling in stem-like cancer phenotypes. [ABSTRACT FROM AUTHOR]

Background/Aims: Coumarins are natural compounds found in many plants that possess medical value by itself and its modified derivatives. Method: Six novel coumarin derivatives were synthesized and examined for their potential anticancer cytotoxicity. Result: Among the 6 derivatives, 3,5-dimethyl-7H-furo[3,2-g]chromen-7-one (DMFC) presented the strongest cytotoxicity against human hepatoma HepG2 cells in vitro with an IC50 value of 8.46 ± 0.28 μM in a 48-hour treatment. Further experiments revealed that DMFC induced apoptosis in HepG2 cells through both extrinsic and intrinsic apoptotic pathways in a p53-dependent manner. Mechanistically, DMFC activated caspases 3, 8 and 9, depolarized mitochondrial membrane potential and induced cytochrome c and apoptosis-inducing factor release. DMFC-induced apoptosis was also characterized by DNA fragmentation, phosphatidylserine externalization and sub-G1 peak in DNA histograms. Moreover, both caspase 8 and 9 inhibitors suppressed the apoptosis induced by DMFC. Western blot analyses revealed that DMFC also significantly increased the expression levels of p53, Fas death receptor, Fas-associated death domain protein and proapoptotic Bcl-2 family members such as Bax, Bad and tBid, as well as decreased the levels of pro-survival members such as Bcl-2 and Bcl-xl. Conclusion: DMFC is potentially an effective therapeutic agent in liver cancer therapy. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: A series of novel indolizinophthalazine-5,12-dione derivatives were designed and synthesized by the reaction of 6,7-dichlorophthalazine-5,8-dione with active methylene reagents (AMR) and pyridine derivatives. Some of synthesized compounds exhibited significant in vitro antiproliferative activity at micromolar level toward four human tumor cell lines, including lung adenocarcinoma cell, large-cell lung carcinoma cell, breast carcinoma cell and ardriamycin-resistance breast carcinoma cell. The DNA topoisomerase IB inhibitory assay indicated that DNA topoisomerase IB might be a biological target of the synthesized compounds. [ABSTRACT FROM AUTHOR]

Abstract: A series of icariin derivatives were synthesized. Their multidrug resistance (MDR) reversal activities were evaluated by MTT assay and the results indicated that the derivatives were the potent modulators of MDR. It was showed that the derivatives significantly increased the intracellular accumulation of ADR in MCF-7/ADR cells compared with drug sensitive MCF-7 cells. The results of bi-directional assay and reverse transcription polymerase chain reaction (RT-PCR) assay showed that the derivatives had high inhibitory activity against P-gp efflux function and significantly down-regulated on the expression of P-gp. [Copyright &y& Elsevier]

Abstract: Series of curcumin derivatives were synthesized; the inhibitory activities on thioredoxin reductase (TrxR) of all analogues were evaluated by DTNB assay in vitro. It is found that most of the analogues can inhibit TrxR in the low micromolar range; Structure-activity relationship analysis reveals that analogues with furan moiety have excellent inhibitory effect on TrxR in an irreversible manner, indicating that the furan moiety may serve as a possible pharmacophore during the interaction of curcumin analogues with TrxR. The effect of selected curcuminoids on growth of different TrxR overexpressed cancer cell lines was also investigated and discussed. [Copyright &y& Elsevier]

Molecular mechanisms associated with tumor metastasis remain poorly understood. Here we report that acquired expression of periostin by colon cancer cells greatly promoted metastatic development of colon tumors. Periostin is overexpressed in more than 80% of human colon cancers examined with highest expression in metastatic tumors. Periostin expression dramatically enhanced metastatic growth of colon cancer by both preventing stress-induced apoptosis in the cancer cells and augmenting endothelial cell survival to promote angiogenesis. At the molecular level, periostin activated the Akt/PKB signaling pathway through the αvβ3 integrins to increase cellular survival. These data demonstrated that the survival-promoting function is crucial for periostin to promote tumor metastasis of colon cancer. [Copyright &y& Elsevier]

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) is a phenomenon in which cells become resistant to structurally and mechanistically unrelated drugs resulting in low intracellular drug concentrations. It is one of the noteworthy problems in malignant tumor clinical therapeutics. So P-gp protein is one of the ideal targets to solve MDR. Based on the lead compound 5m obtained from our previous work, a series of furan derivatives featuring alkyl-substituted phenols and 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline were designed and synthesized as reversal agents against P-gp in this paper. Compound 16 containing isopropoxy possessed good potency against P-gp mediated MDR in MCF-7/ADR (IC 50 (doxorubicin) = 0.73 μM, RF = 69.6 with 5 μM 16 treated). Western blot results and Rh123 accumulation assays showed that 16 effectively inhibited P-gp efflux function but not its expression. The preliminary structure–activity relationship and docking studies demonstrated that compound 16 would be a potential P-gp inhibitor. Most worthy of mention is that compound 16 has achieved satisfactory results in combination with a variety of anti-tumor drugs, such as doxorubicin, paclitaxel, and vincristine. This study forwards a hopeful P-gp inhibitor for withstanding malignant tumor cell with multidrug resistance setting the basis for further studies. [Display omitted] • Eighteen 5-alkoxyphenyl-2-(6,7-dimethoxy-1,2,3,4-tetrahydroiso- quinolinecarboxamide)furan derivatives were designed and synthesized. • Title compounds were tested as reversal agents against P-glycoprotein mediated multidrug resistance in MCF-7/ADR cells. • SARs demonstrated that the alkoxy-substituent effect was key in enhancing the P-gp inhibitory activity and corroborated by docking study. • P-gp efflux function was abrogated effectively by compound 16 without down-regulating P-gp expression. • >60 fold increase in intracellular concentration was achieved for doxorubicin and vincristine. [ABSTRACT FROM AUTHOR]