miRNA-101在甲状腺髓样癌中抑癌机制的研究

Insights into tumor suppression mechanism of miRNA-101 in medullary thyroid carcinoma

目的:研究microRNA-101在甲状腺髓样细胞中的抑癌机制。方法:首先用荧光定量PCR技术检测甲状腺髓样癌组织中microRNA-101的表达。接着采用microRNA-101模拟物干预法,并用流式细胞仪技术,Transwell实验等方法,对实验组和对照组细胞的增殖、迁移和凋亡进行比较。此外,还通过Western blot、报告基因检测法、流式细胞仪技术和Transwell实验确定miRNA-101靶基因以及相应的抑癌机制。结果:miRNA-101在甲状腺髓样癌组织中的表达相比癌旁组织下调(P<0.01)。与阴性对照组相比,miRNA-101模拟物转染组的甲状腺髓样癌细胞的增殖和迁移受到显著抑制,而凋亡率显著提高。Western blot和荧光素酶报告实验证实SOX9基因是miRNA-101下游的靶基因并被其下调。SOX9基因敲除可抑制甲状腺髓样癌细胞增殖,迁移和促进癌细胞凋亡。结论:microRNA-101通过靶向下调SOX9基因的表达抑制甲状腺髓样癌细胞的增殖和迁移,加速甲状腺髓样癌细胞的凋亡。

AIM： To explore the tumor suppression mechanism of microRNA-101 in human medullary thyroid carcinoma cells（ TT cells）. METHODS： The expression of microRNA-101 in tissue samples from patients with medullary thyroid carcinoma was analyzed by quantitative RT-PCR. Then TT cells were divided into two groups and transfected with miRNA-101 mimics/negative control. Flow cytometry and Transwell assay were used to detect TT cell cycle distribution,apoptotic rate as well as cell migration. Moreover,Western blot,flow cytometry,luciferase and Transwell assays were used to predict target gene of miRNA-101 as well as its underlying mechanism. RESULTS： MiRNA-101 was significantly down-regulated in medullary thyroid carcinoma tissues. MiRNA-101 mimics＇ transfection significantly inhibited TT cell proliferation and migration,induced cell apoptosis comparing with negative control. Western blot and luciferase assay revealed that SOX9 gene expression was down-regulated by miRNA-101. Silencing of SOX9 by siRNA showed similar effects with miRNA-101 over-expression. CONCLUSION： MicroRNA-101 inhibits proliferation,migration and induces apoptosis of human medullary thyroid carcinoma cells by targeting SOX9 gene.