IGFBP3基因启动子高甲基化所致表达下降促进胃癌化疗耐药  

Decreased Expression of IGFBP3 Gene Promoter Induced by Hypermethylation Promoters Promotes Chemoresistance in Gastric Cancer

作　　者：刘立宇[1] 刘霆[1] 陈柏林 李佳 李康 LIU Li-yu;LIU Ting;CHEN Bo-lin;LI Jia;LI Kang(Department of Gastroenterology, Xiangya Hospital Central South University, Changsha, Hunan, 410008, China;Second Department of Thoracic Medicine, Hunan Cancer Hospital / The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, China)

机构地区：[1]中南大学湘雅医院消化内科,湖南长沙410008 [2]湖南省肿瘤医院/中南大学湘雅医学院附属肿瘤医院胸部内二科,湖南长沙410013

出　　处：《现代生物医学进展》2019年第8期1441-1445,1475,共6页Progress in Modern Biomedicine

基　　金：2018年度湖南省自然科学基金项目(2018JJ2664)

摘　　要：目的:研究胰岛素样生长因子结合蛋白3(IGFBP3)在胃癌化疗敏感及化疗耐药细胞和组织中的表达情况,初步探讨其在胃癌化疗耐药中的作用及表达异常机制。方法:采用荧光实时定量PCR(qRT-PCR)及蛋白质免疫印迹实验(WB)的方法检测IGFBP3在化疗药物敏感的胃癌细胞AZ521、SC-M1,对应顺铂耐药细胞AZ521/cisplatin、SC-M1/cisplatin和胃癌组织中的表达水平;在降低和增加IGFBP3表达量后,采用细胞计数试剂盒-8(CCK-8)试剂及流式细胞术(FCM)检测胃癌细胞对化疗药物的敏感性的变化;甲基化特异性PCR(MSP)检测IGFBP3基因启动子区甲基化水平。结果:IGFBP3在化疗耐受的胃癌细胞及组织中表达低于化疗敏感的胃癌细胞及组织(P<0.05);在敏感细胞中干扰IGFBP3表达可促进胃癌细胞的耐药性,而在耐药细胞中恢复IGFBP3表达可显著逆转耐药性;MSP结果显示,IGFBP3的表达受DNA甲基化调控,耐药细胞中IGFBP3启动子高甲基化导致其表达下降(P<0.05);甲基转移酶抑制剂地西他滨(DAC)处理耐药的胃癌细胞,可恢复IGFBP3表达,并提高其对化疗药物的敏感性(P<0.05)。结论:IGFBP3启动子区发生DNA高甲基化导致其表达下降,使得化疗药物诱导胃癌细胞发生凋亡的能力下降,最终导致胃癌细胞的化疗耐药。Objective: To study the expression of insulin-like growth factor binding protein 3(IGFBP3) in chemosensitivity and chemosensitivity cells and tissues of gastric cancer, and to explore its function and mechanism of abnormal expression in the chemoresistance of gastric cancer. Methods: The expression of IGFBP3 in chemotherapeutic drug-sensitive gastric cancer cells AZ521 and SC-M1, expressions of cisplatin-resistant cells AZ521/cisplatin, SC-M1/cisplatin and gastric cancer were detected by real-time quantitative fluorescence polymerase chain reaction(qRT-PCR) and Western blot assay(WB). After decreasing and increasing the expression of IGFBP3, the sensitivity of gastric cancer cells to chemotherapeutic drugs was detected by cell counting kit-8(CCK-8)reagent and flow cytometry(FCM). The promoter methylation level of IGFBP3 was determined by the methylation specific PCR(MSP)assay. Results: The expression of IGFBP3 in chemo-tolerant gastric cancer cells and tissues was lower than that in chemo-sensitive gastric cancer cells and tissues(P <0.05). Interference of IGFBP3 expression in sensitive cells can promote drug resistance of gastric cancer cells. While recovery of IGFBP3 expression in drug-resistant cells can significantly reversed drug resistance. MSP results showed that the expression of IGFBP3 was regulated by DNA methylation. Higher methylation of IGFBP3 promoter in drug-resistant cells resulted in decreased expression of IGFBP3(P <0.05). The drug-resistant gastric cancer cells were treatment with methyltransferase inhibitor dicetabine(DAC), the expression of IGFBP3 was restored, its sensitivity to chemotherapeutic drugs were increased(P<0.05).Conclusion: DNA hypermethylation in the promoter region of IGFBP3 leads to a decrease in its expression, which leads to a decrease in the ability of chemotherapeutic drugs to induce apoptosis of gastric cancer cells, and ultimately leads to chemotherapeutic resistance of gastric cancer cells.

关 键 词：IGFBP3 胃癌 化疗耐药 甲基化 

分 类 号：R-33[医药卫生] R735.2