miR-34a regulates cisplatin-induce gastric cancer cell death by modulating PI3K/AKT/survivin pathway.
The purposes of this study were to determine the expression profiles of microRNA-34a (miR-34a) in human gastric cancer cell line (SGC-7901) and cisplatin-resistant cell lines (SGC-7901/DDP), and to establish the correlation between miR-34a expression profile and the sensitivity of human gastric cancer cell to cisplatin-based pattern, thereby providing new methods and strategies for treating gastric cancer. Gastric cancer cell line (SGC-7901) and cisplatin-resistant cell line (SGC-7901/DDP) were cultivated in vitro, respectively. Quantitative real-time PCR (qRT-PCR) and Western blot were utilized to determine the expression profiles of miR-34a and survivin in both gastric cancer cell lines. With miR-34a mimic and miR-34a inhibitor transfected into SGC-7901 and SGC-7901/DDP for 48 h, post-transfection changes of miR-34a expression was determined; the effects of miR-34a ectopic expression on the viability of cisplatin-induce gastric cancer cell were assayed by the MTT method. The effects of miR-34a ectopic expression on apoptosis of cisplatin-induce gastric cancer cell were determined by Annexin V/propidium iodide (PI) double staining method and flow cytometry. The effects of miR-34a ectopic expression on the AKT and p-AKT expression of cisplatin-induce gastric cancer cells were determined by Western blot and flow cytometry with the PI3K pathway inhibitor Wortmannin. As shown by qRT-PCR and Western blot analyses, the expression of miR-34a in cisplatin-resistant cell lines decreased significantly in comparison to that of SGC-7901 cell line (p < 0.05), while significant up-regulation of survivin expression was also observed (p < 0.05). Compared with the control group, the expression of miR-34a increased significantly in SGC-7901 cells transfected with miR-34a mimic for 48 h (p < 0.01). After miR-34a inhibitor transfection, the expression of miR-34a decreased significantly (p < 0.05). The viability of cisplatin-induce gastric cancer cells increased significantly (p < 0.05) with significant decrease of apoptosis after miR-34a expression inhibition, as demonstrated by MTT and flow cytometry with miR-34a over-expression, the viability of cisplatin-induce gastric cancer cells decreased significantly (p < 0.05), with significant apoptosis increase (p < 0.05). As shown by Western blot and flow cytometry, in comparison to the control group, Wortmannin could inhibit miR-34a inhibitor and DDP induced up-regulation of p-AKT significantly (p < 0.05) and stimulated apoptosis. In conclusion, miR-34a expression was down-regulated in cisplatin-resistant cell lines. miR-34a over-expression could improve the sensitivity of gastric cancer cells against cisplatin-based chemotherapies, with PI3K/AKT/survivin signaling pathway possibly involved in the mechanism.
Department of Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Weiguo
W
Cao
Weiping
W
Yang
Rong
R
Fan
Hao
H
Li
Jinsong
J
Jiang
Mei
M
Geng
Yening
Y
Jin
Yunlin
Y
Wu
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D053492:Elafin / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology
D053492:Elafin; C522425:MIRN34 microRNA, human; D035683:MicroRNAs; C506806:PI3 protein, human; D051057:Proto-Oncogene Proteins c-akt; D002945:Cisplatin