Hint1诱导胃癌化疗耐药的临床观察及分子机制研究

Study on clinical observation and molecular mechanism of chemoresistance in gastric cancer induced by Hint1

【目的】观察组氨酸三聚体核苷结合蛋白1基因(Histidine triad nucleotide binding protein 1 gene,Hint1)对胃癌患者化疗疗效的影响并初步研究其可能机制。【方法】收集临床胃癌及癌旁组织,检测Hint1基因及蛋白表达并评估与化疗疗效的相关性,随后建立Hint1沉默胃癌细胞株,MTT观察沉默组及对照组对顺铂的敏感性,,免疫荧光检测DNA双链断裂(DNA double strands breaks,DSB),蛋白印迹测定共济失调毛细血管扩张综合征突变基因(ataxia telangiectasis mutated,ATM)-周期素依赖性激酶2(Cyclin-dependent kinase 2,Chk2)信号通路。【结果】Hint1肿瘤组织低表达组患者化疗有效率达82.35%,而非低表达组仅为61.54%,细胞实验显示沉默Hint1后胃癌细胞对顺铂敏感性增加,DSB损伤持续时间延长,ATM-Chk2活性显著低于对照组。【结论】Hint1可能通过调控ATM-Chk2信号通路,参与DSB损伤修复,降低胃癌化疗的敏感性。

【Objective】To observe the effect of histidine triad nucleotide binding protein 1 gene（Hint1） on chemotherapy of gastric cancer and preliminarily explore its possible molecular mechanism.【Methods】Gastric cancer and adjacent tissues were collected clinically. The expressions of Hint1 gene and protein were detected and the relevance to chemotherapy efficacy was assessed. Hint1 was knockdown by RNA interference in gastric cancer cells. MTT assay was used to evaluate the responses to cisplatin in gastric cells with different Hint1 expressions. DSB was measured with immunofluorescence assay. ATM-Chk2 signaling pathway of DNA damage was determined by western blot.【Results】The effective rate of chemotherapy in patients with lower Hint1 expression in tumors rose obviously. Cell experiments in vitro showed that gastric cancer cells with silencing Hint1 were more sensitive to cisplatin. DSB damage was prolonged. ATM- Chk2 activity of gastric cancer cells with silencing Hint1 was significantly lower than that in control group.【Conclusion】Hint1 possibly involves in DSB repair via ATM-Chk2 signaling pathway, which may reduce the sensitivity of gastric cancer cells to chemotherapy.