Rosmarinic acid reduces the resistance of gastric carcinoma cells to 5-fluorouracil by downregulating FOXO4-targeting miR-6785-5p
Rosmarinic acid reduces the resistance of gastric carcinoma cells to 5-fluorouracil by downregulating FOXO4-targeting miR-6785-5p
复制标题
迷迭香酸通过下调 FOXO4 靶向 miR-6785-5p 降低胃癌细胞对 5-氟尿嘧啶的耐药性
DOI：
10.1016/j.biopha.2018.10.061
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Chen Yu
中科院分区：
文献类型：
--
作者：
Chen Yu
ObjectiveChemoresistance has been a major problem in cancer chemotherapy. The present study aimed to investigate the effect of Rosmarinic acid (RA) on chemoresistance to 5-Fu and its molecular mechanism in gastric carcinoma.MethodsCCK8 cell proliferation and apoptosis assay were used to evaluate the effect of RA on chemoresistance to 5-Fu in GC cells. RNA microarray was used to identify miRNA involved. Expression level of miRNA in GC cells was determined by RT-PCR. Down- or up-regulating of miRNA in the GC cells was performed by transfection of RNA interference or expression vectors in the GC cells. Double luciferase reporter assay was used to verify miRNA target genes. Expression of P-glycoprotein and Bax was analyzed with Western blot.ResultsRA treated SGC7901/5-Fu cells showed significant increased chemosensitivity to 5-Fu. The IC50 of 5-Fu was significantly reduced in RA treated SGC7901/5-Fu cells (70.43 ± 1.06 μg/mL) compared to untreated SGC7901/5-Fu cells (208.6 ± 1.09 μg/mL) (P < 0.05). Apoptosis rate was significantly increased in RA+5-Fu treated SGC7901/5-Fu cells compared to 5-FU treatment alone (P < 0.01). Two miRNAs, namely miR-642a-3p and miR-6785-5p, were identified to be involved in the chemo-sensitizing effect of RA in the SGC7901/5-Fu cells. RA treated SGC7901/5-Fu cells showed reduced expression levels of miR-642a-3p and miR-6785-5p compared to untreated SGC7901/5-Fu cells (P < 0.05). Down- or up-regulation of miR-6785-5p increased or reduced chemosensitivity of gastric carcinoma cells to 5-Fu, respectively. RA treated SGC7901/5-Fu and the SGC7901/5-Fu-Si cells showed significantly increased FOXO4 expression (P < 0.01). Double luciferase reporter assay confirmed miR-6785-5p directly targets FOXO4 to regulate its expression. RA significantly reduced P-gp expression and increased Bax expression in SGC7901/5-Fu and the SGC7901/5-Fu-Si cells (P < 0.05).ConclusionRA enhances chemosensitivity of resistant gastric carcinoma SGC7901 cells to 5-Fu by downregulating miR-6785-5p and miR-642a-3p and increasing FOXO4 expression. These study suggest the potential for RA as a multidrug resistance-reversing agent in GC.
