m iR-335通过靶向生存素对乳腺癌细胞增殖的调控作用

目的：探讨miR‐335通过靶向生存素对乳腺癌细胞增殖的调控作用。方法（1）选取乳腺癌组织及癌旁正常组织，分别采用RT‐PCR、Western blot检测组织中 miR‐335及生存素蛋白表达。（2）选取乳腺癌细胞系 MCF‐7，分别转染 miR‐335 mimic及mimic对照组，采用RT‐PCR、Western blot检测组织中miR‐335及生存素蛋白表达。（3）选取乳腺癌细胞系MCF‐7，分别将野生型survivin 3′‐UTR质粒（survivin‐wt）和突变型survivin 3′‐UTR质粒（survivin‐Mut）与miR‐335 mimic或模拟物阴性对照（NC）共转染至乳腺癌细胞系MCF‐7，双荧光素酶报告基因检测细胞荧光素酶活性。（4）选取乳腺癌细胞系MCF‐7，分别转染mimic对照组、miR‐335 mimic及miR‐335 mimic＋survivin ，采用四甲基偶氮唑蓝（MTT）法检测各组细胞增殖活性。结果（1）与癌旁组织相比较，乳腺癌组织中miR‐335表达显著降低（P＜0．05），同时生存素蛋白表达显著增高（P＜0．05）。（2）与转染mimic对照组相比较，转染miR‐335 mimic可使乳腺癌细胞MCF‐7中miR‐335表达上调（P＜0．05），同时生存素蛋白表达表达下调（P＜0．05）。（3）与转染NC相比较，共转染miR‐335 mimic与survivin‐wt可使MCF‐7荧光素酶活性降低（P＜0．05），而共转染miR‐335 mimic与survivin‐Mut则MCF‐7荧光素酶活性无显著性变化（P＞0．05）。（4）转染miR‐335mimic后，MCF‐7增殖活性较转染mimic对照组显著降低（P＜0．05）；而转染miR‐335 mimic＋survivin后，MCF‐7增殖活性较单纯转染miR‐335 mimic显著提高（P＜0．05），但仍显著低于转染mimic对照组（P＜0．05）。结论在乳腺癌组织中miR‐335呈现低表达，生存素呈现高表达；而miR‐335可通过靶向生存素抑制乳腺癌细胞系MCF‐7增殖。

miR-335 regulate cell proliferation by targeting survivin in breast cancer cells MCF-7

Objective To evaluate the effect of miR‐335 regulate cell proliferation by targeting survivin in breast cancer cells MCF‐7 .Methods (1)Chose breast cancer tissue and para‐carcinoma tissue ,and used RT‐PCR or Western blot to detect the expres‐sion of miR‐335 and survivin protein .(2)Chose breast cancer cells MCF‐7 ,respectively transfected miR‐335 mimic and mimic con‐trol .The expression of miR‐335 and survivin protein were detected by RT‐PCR or Western blot .(3)Chose breast cancer cells MCF‐7 ,respectively co‐transfection wild type survivin 3′‐UTR(survivin‐wt)or mutant type urvivin 3′‐UTR(survivin‐Mut)and miR‐335 mimic or negative control(NC)to breast cancer cells MCF‐7 .The cell luciferase activity were detected by dual‐luciferase report gene experiment .(4)Chose breast cancer cells MCF‐7 ,respectively transfected mimic control ,miR‐335 mimic and miR‐335 mimic+ sur‐vivin .The cell proliferation activity of each group were detected by MTT method .Results (1)Compared with para‐carcinoma tis‐sue ,the miR‐335 expression of breast cancer tissue significantly decreased(P<0 .05) ,and the survivin protein expression of breast cancer tissue significantly increased(P<0 .05) .(2)Compared with transfection mimic control ,transfection miR‐335 mimic can made the miR‐335 expression of MCF‐7 increased(P<0 .05) ,and made the survivin protein expression of MCF‐7 decreased(P<0 .05) . (3)Compared with transfection NC ,co‐transfection miR‐335 mimic and survivin‐wt can made luciferase activity of MCF‐7 signifi‐cantly decreased(P<0 .05) ,but the luciferase activity of MCF‐7 was not significantly changes after co‐transfection miR‐335 mimic and survivin‐Mut (P>0 .05) .(4)Compared with transfection mimic control ,the MCF‐7 proliferative activity significantly decreased after transfection miR‐335mimic(P<0 .05) .Compared with transfection miR‐335 mimic ,the MCF‐7 proliferative activity signifi‐cantly increased after transfection miR‐335 mimic+survivin(P<0 .05) ,but still lower than transfection mimic control(P<0 .05) . Conclusion In breast cancer tissue ,the miR‐335 show low expression ,and survivin show high expression .miR‐335 can target sur‐vivin to inhibit the proliferation activity of breast cancer cells MCF‐7 .