miR-374靶向下调TRIM35表达可促进乳腺癌细胞增殖和侵袭

MiR-374 promoting proliferation and invasion of breast cancer cells by targeting and down-regulating TRIM35

目的探讨miR-374在乳腺癌中的作用及其与三基序蛋白35(TRIM35)的关系。方法选取乳腺癌患者42例,收集癌组织和癌旁组织(距肿瘤切缘>2 cm)。收集所有患者的临床病理资料。检测癌组织和癌旁组织miR-374和TRIM35的表达。根据不同处理方法将乳腺癌细胞系MCF-7分为3组:对照组(未作任何处理)、干扰组(加入100 nmol/L miR-374抑制剂)和空载体组(加入100 nmol/L随机序列)。采用细胞增殖试验和Transwell试验评估miR-374对乳腺癌细胞系MCF-7增殖活性和侵袭能力的影响。采用双荧光素酶报告基因实验分析miR-374和TRIM35之间的相互作用。结果与癌旁组织比较,癌组织miR-374相对表达量显著升高(P<0.001),TRIM35相对表达量显著降低(P<0.001)。不同肿瘤大小和有无淋巴转移、远隔转移的乳腺癌患者之间miR-374相对表达量差异均有统计学意义(P<0.05)。不同年龄和TNM分期的乳腺癌患者之间miR-374相对表达量差异均无统计学意义(P>0.05)。干扰组miR-374相对表达量显著低于对照组和空载体组(P<0.001)。干扰组培养48、72 h后的细胞增殖率和侵袭细胞数均显著低于空载体组和对照组(P<0.001),TRIM35相对表达量显著高于空载体组和对照组(P<0.001)。双荧光素酶报告基因实验结果显示,miR-374可直接抑制靶基因TRIM35的转录表达。结论miR-374与TRIM35存在相互作用,miR-374通过靶向下调TRIM35表达促进乳腺癌细胞的增殖和侵袭。

Objective To investigate the role of miR-374 in breast cancer and the relationship between miR-374 and tripartite motif-containing protein 35(TRIM35).Methods A total of 42 patients with breast cancer were enrolled,and cancer tissues and adjacent tissues(>2 cm away from tumor resection margin)were collected,and the data of patients were collected as well.The expression of miR-374 and TRIM35 were determined in cancer tissues and adjacent tissues.Breast cancer cell line MCF-7 was classified into 3 groups according to different treatment methods,including control group(without any treatment),interference group(adding 100 nmol/L miR-374 inhibitor)and mock-vehicle group(adding 100 nmol/L negative control sequence).The effects of miR-374 on the proliferative activity and invasiveness of breast cancer cell line MCF-7 were evaluated by cell proliferation assay and Transwell assay.Dual luciferase reporter gene assay was used to determine the interaction between miR-374 and TRIM35.Results The expression of miR-374 in cancer tissues was higher than that in adjacent tissues(P<0.001).TRIM35 relative expression in cancer tissues was lower than that in adjacent tissues(P<0.001).The miR-374 relative expression had statistical significance with different breast tumor sizes,distant metastasis and lymphatic metastasis(P<0.05).There was no statistical significance for miR-374 relative expression with different ages and TNM stages(P>0.05).The relative expression of miR-374 in interference group was lower than those in control group and mock-vehicle group(P<0.001).The cell proliferation rate and the number of invasive cells in interference group were lower than those in mock-vehicle group and control group(P<0.001).TRIM35 relative expressions were higher than those in mock-vehicle group and control group(P<0.001).Dual luciferase reporter gene assay confirmed that miR-374 directly inhibited the transcriptional expression of target gene TRIM35.Conclusions MiR-374 interacts with TRIM35,and miR-374 promotes the proliferation and invasion of breast cancer cells by targeting and downregulating the expression of TRIM35.