MiR-125b在甲状腺癌患者中的表达及其意义

目的探讨miR-125b在甲状腺癌患者中的表达及其意义。方法选取甲状腺乳头状癌组织及其配对的癌旁组织各20例,所有患者均经超声及病理确诊。实时荧光定量PCR检测miR-125b mRNA的表达,Western Blot检测Foxp3、LC 3Ⅰ和LC 3Ⅱ蛋白的表达。将人甲状腺乳头状癌细胞系MDA-T32随机分为3组:对照组(不处理)、阴性对照组(转染无义序列)和miR-125b组(转染miR-125b mimics),实时荧光定量PCR检测miR-125b mRNA的表达,MTT法检测癌细胞对顺铂的敏感性,Western Blot检测Foxp3、LC 3Ⅰ和LC 3Ⅱ蛋白的表达。结果与癌旁组织对比,甲状腺癌组织中MiR-125b mRNA的表达显著降低(P <0.05),Foxp3蛋白表达显著增加(P <0.05)。与对照组相比,miR-125b组细胞中MiR-125b mRNA的表达显著增加(P <0.05),Foxp3蛋白的表达显著降低(P <0.05)。与对照组相比,在顺铂浓度为30μg/ml时,miR-125b组细胞活性显著降低(P <0.05)。在顺铂浓度为0、15、60、120μg/ml时,各组间细胞活性的对比无显著差异(P> 0.05)。与癌旁组织对比,甲状腺癌组织中LC 3Ⅱ蛋白的表达显著增加(P <0.05)。与对照组相比,miR-125b组细胞中LC 3Ⅱ蛋白的表达显著降低(P <0.05)。LC 3Ⅰ蛋白的表达在各组间对比无显著变化(P> 0.05)。结论miR-125b在甲状腺癌中下调,miR-125b介导的Foxp3下调可抑制自噬,并增强甲状腺癌细胞对顺铂的敏感性。

Expression and Significance of miR-125b in Patients with Thyroid Carcinoma

Objective To investigate the expression and significance of miR-125b in patients with thyroid cancer. Methods 20 thyroid papillary carcinoma tissues and their matched paracancerous tissues collected and preserved were selected. All patients were diagnosed by ultrasound and pathology. The expression of miR-125b mRNA was detected by real-time fluorescent quantitative PCR,and the expressions of Foxp3,LC 3Ⅰ and LC 3 Ⅱ protein were detected by Western Blot. Human thyroid papillary carcinoma cell line MDA-T32 was randomly divided into 3 groups: control group( no treatment),negative control group( transfection nonsense sequence) and miR-125b group( transfected miR-125b mimics),the expression of miR-125b mRNA was detected by real-time fluorescent quantitative PCR,the sensitivity of cancer cells to cisplatin was detected by MTT assay. The expressions of Foxp3,LC 3Ⅰ and LC 3 Ⅱ protein were detected by Western Blot. Results Compared with adjacent tissues,the expression of miR-125b mRNA in thyroid carcinoma tissues was significantly decreased( P < 0. 05),and the expression of Foxp3 protein was significantly increased( P < 0. 05). Compared with the control group,the expression of miR-125b mRNA in the miR-125b group was significantly increased( P < 0. 05),and the expression of Foxp3 protein was significantly decreased( P < 0. 05). Compared with the control group,the cell viability in the miR-125b group was significantly decreased when the concentration of cisplatin was 30 μg/ml( P < 0. 05). There was no significant difference in cell viability among the 3 groups at concentrations of cisplatin of 0,15,60,and 120 μg/ml( P > 0. 05). Compared with adjacent tissues,the expression of LC 3 Ⅱ protein in thyroid cancer tissues was significantly increased( P < 0. 05). Compared with the control group,the expression of LC 3 Ⅱ protein in the miR-125b group was significantly decreased( P < 0. 05). The expression of the LC 3Ⅰ protein showed no significant change in the 3 groups( P > 0. 05). Conclusion miR-125b is down-regulated in thyroid cancer,and miR-125b-mediated down-regulation of Foxp3 can inhibit autophagy and enhance the sensitivity of thyroid cancer cells to cisplatin.