Abstract：
BACKGROUND: Drug resistance is one of the most critical problems in gastric cancer therapy. This study was performed to investigate the valproic acid effects on the proliferation of sensitive and resistant cell lines of human gastric cancer, and to explore the mechanism of the agent on multi drug resistance and apoptosis genes.
METHODS: The cytotoxicity effect of valproic acid on the EPG85.257 and EPG85.257RDB cells was assessed by the MTT assay, and the IC50 concentration was evaluated. Apoptosis, genotoxicity, and drug resistance pump activity were evaluated using comet assay, Real-time PCR, and flow cytometry, respectively. Cell proliferation was assayed using a scratch test.
RESULTS: Dose-dependent toxicity was recorded after treatment of cells with valproic acid. Valproic acid represented a significant growth inhibition on EPG85.257 cells with IC50 values of 5.84 µM and 4.78 µM after 48 h and 72 h treatment, respectively. In contrast, the drug-resistant counterpart represented 8.7 µM and 7.02 µM IC50 values after the same treatment time. Valproic acid induced PTEN, Bcl2, P53, Bax, P21, and caspase3 expression in EPG85.257 cells, whereas p21, p53, PTEN, and ABCB1 were overexpressed in EPG5.257RDB. Valproic acid hindered cell migration in both cell lines (P < 0.01). Valproate genotoxicity was significantly higher in the parent cells than in their resistant EPG85.257RDB counterparts. Valproate led to a 62% reduction in the daunorubicin efflux of the MDR1 pump activity.
CONCLUSIONS: Valproate can affect drug resistance in gastric cancer via a unique mechanism independent of MDR1 expression.
METHODS: The cytotoxicity effect of valproic acid on the EPG85.257 and EPG85.257RDB cells was assessed by the MTT assay, and the IC50 concentration was evaluated. Apoptosis, genotoxicity, and drug resistance pump activity were evaluated using comet assay, Real-time PCR, and flow cytometry, respectively. Cell proliferation was assayed using a scratch test.
RESULTS: Dose-dependent toxicity was recorded after treatment of cells with valproic acid. Valproic acid represented a significant growth inhibition on EPG85.257 cells with IC50 values of 5.84 µM and 4.78 µM after 48 h and 72 h treatment, respectively. In contrast, the drug-resistant counterpart represented 8.7 µM and 7.02 µM IC50 values after the same treatment time. Valproic acid induced PTEN, Bcl2, P53, Bax, P21, and caspase3 expression in EPG85.257 cells, whereas p21, p53, PTEN, and ABCB1 were overexpressed in EPG5.257RDB. Valproic acid hindered cell migration in both cell lines (P < 0.01). Valproate genotoxicity was significantly higher in the parent cells than in their resistant EPG85.257RDB counterparts. Valproate led to a 62% reduction in the daunorubicin efflux of the MDR1 pump activity.
CONCLUSIONS: Valproate can affect drug resistance in gastric cancer via a unique mechanism independent of MDR1 expression.
摘要：
背景：耐药是胃癌治疗中最关键的问题之一。本研究旨在研究丙戊酸对人胃癌敏感和耐药细胞系增殖的影响。并探讨该药对多药耐药和凋亡基因的作用机制。
方法：通过MTT法评估丙戊酸对EPG85.257和EPG85.257RDB细胞的细胞毒性作用，并评估IC50浓度。细胞凋亡,遗传毒性，并使用彗星试验评估耐药泵的活性，实时PCR,和流式细胞术，分别。使用划痕试验测定细胞增殖。
结果：用丙戊酸处理细胞后记录剂量依赖性毒性。丙戊酸对EPG85.257细胞具有显著的生长抑制作用，48小时和72小时处理后的IC50值分别为5.84µM和4.78µM。分别。相比之下,在相同的治疗时间后，耐药对应物的IC50值分别为8.7µM和7.02µM。丙戊酸诱导PTEN,Bcl2,P53,Bax,P21和caspase3在EPG85.257细胞中的表达，而p21，p53，PTEN，ABCB1在EPG5.257RDB中过表达。丙戊酸阻碍了两种细胞系的细胞迁移（P<0.01）。丙戊酸在亲本细胞中的遗传毒性明显高于其抗性EPG85.257RDB对应物。丙戊酸导致MDR1泵活性的柔红霉素外排减少62%。
结论：丙戊酸钠通过一种独立于MDR1表达的独特机制影响胃癌耐药。
方法：通过MTT法评估丙戊酸对EPG85.257和EPG85.257RDB细胞的细胞毒性作用，并评估IC50浓度。细胞凋亡,遗传毒性，并使用彗星试验评估耐药泵的活性，实时PCR,和流式细胞术，分别。使用划痕试验测定细胞增殖。
结果：用丙戊酸处理细胞后记录剂量依赖性毒性。丙戊酸对EPG85.257细胞具有显著的生长抑制作用，48小时和72小时处理后的IC50值分别为5.84µM和4.78µM。分别。相比之下,在相同的治疗时间后，耐药对应物的IC50值分别为8.7µM和7.02µM。丙戊酸诱导PTEN,Bcl2,P53,Bax,P21和caspase3在EPG85.257细胞中的表达，而p21，p53，PTEN，ABCB1在EPG5.257RDB中过表达。丙戊酸阻碍了两种细胞系的细胞迁移（P<0.01）。丙戊酸在亲本细胞中的遗传毒性明显高于其抗性EPG85.257RDB对应物。丙戊酸导致MDR1泵活性的柔红霉素外排减少62%。
结论：丙戊酸钠通过一种独立于MDR1表达的独特机制影响胃癌耐药。
