Zhang Mingliang, Guo Wei, Qian Jun, Wang Benzhong
Department of Breast Surgery, The First Affiliated Hospital of AnHui Medical University, AnHui province, 230032 China; Department of Oncology Surgery, The First Affiliated Hospital of BengBu Medical College, AnHui province, 233000 China.
Department of Oncology Surgery, The First Affiliated Hospital of BengBu Medical College, AnHui province, 233000 China.
Open Med (Wars). 2016 Mar 30;11(1):78-82. doi: 10.1515/med-2016-0015. eCollection 2016.
The inhibitory role of microRNA-29a (miR-29a) has been assessed in breast cancer cells. Herein, we analyze the underlying mechanisms of its role in cell cycle progression in breast cancer cells.
We applied real-time polymerase chain reaction (PCR) to detect the expression of miR-29 in breast cancer cell lines. Then one of the cell lines, MDA-MB-453, was transfected with mimics of miR-29a. The cell cycle was analyzed by fluorescence-activated cell sorting after staining the cells with propidium iodide. Real-time PCR, luciferase assay and western blot were used together to verify the regulation of the predicted target, cell division cycle 42 (CDC42) by miR-29a.
MiR-29s were decreased in our selected mammary cell lines, among which miR-29a was the dominant isoform. Overexpression of miR-29a caused cell cycle arrest at the G0/G1 phase. We further found that miR-29a could target the expression of CDC42, which is a small GTPase associated with cell cycle progression.
We suggest that miR-29a exerts its tumor suppressor role in breast cancer cells partially by arresting the cell cycle through negative regulation of CDC42.
已评估微小RNA-29a（miR-29a）在乳腺癌细胞中的抑制作用。在此，我们分析其在乳腺癌细胞周期进程中作用的潜在机制。
我们应用实时聚合酶链反应（PCR）检测乳腺癌细胞系中miR-29的表达。然后用miR-29a模拟物转染其中一个细胞系MDA-MB-453。在用碘化丙啶对细胞染色后，通过荧光激活细胞分选分析细胞周期。联合使用实时PCR、荧光素酶测定和蛋白质印迹来验证miR-29a对预测靶点细胞分裂周期42（CDC42）的调控。
在我们所选的乳腺细胞系中，miR-29s表达降低，其中miR-29a是主要的异构体。miR-29a的过表达导致细胞周期停滞在G0/G1期。我们进一步发现miR-29a可以靶向CDC42的表达，CDC42是一种与细胞周期进程相关的小GTP酶。
我们认为miR-29a在乳腺癌细胞中发挥其肿瘤抑制作用，部分是通过对CDC42的负调控使细胞周期停滞来实现的。
