miR-148b在肺腺癌中的表达及其功能分析

目的 探讨微小RNA-148b（miR-148b）在肺腺癌组织和细胞株中的表达及临床意义。方法 采用实时定量PCR检测13例肺腺癌及癌旁组织中miR-148b的表达，并检测其在肺腺癌细胞株H1437、H1975、A549、PC14/B和正常人肺上皮细胞株HBE中的表达，选取肺腺癌细胞株miR-148b表达水平最低者分别转染miR-148b模拟物（mimics）和miR-148b control。通过MTT检测、低密度细胞集落形成实验、Transwell实验检测miR-148b对细胞增殖、集落形成和侵袭能力的影响。结果 miR-148b在肺腺癌和癌旁组织中的相对表达量分别为0.61±0.42和0.91±0.32（P＜0.05）；与正常肺上皮细胞株HBE（相对表达量设为1.00）比较，4种肺腺癌细胞株H1437、H1975、A549、PC14/B中miR-148b的表达量分别为0.42±0.08、0.38±0.02、0.29±0.03和0.21±0.04（P＜0.05），选取PC14/B细胞株进行后续实验。MTT检测显示，实验第3天，转染miR-148b mimics的PC14/B细胞吸光值明显低于转染miR-148b control组（P＜0.05）；低密度细胞集落形成实验中，与转染了miR-148b control的PC14/B细胞（相对克隆数设为100）相比，转染miR-148b mimics的PC14/B细胞的相对克隆数为47±8，差异有统计学意义（P＜0.05）；Transwell实验显示，转染miR-148b mimics后穿过基底膜的相对PC14/B细胞数为82±22，与miR-148b control组（200±34）相比，差异有统计学意义（P＜0.05）。结论 miR-148b在肺腺癌组织和细胞中表达下调，且可抑制肺腺癌PC14/B细胞株的增殖、集落形成和侵袭能力。

Expression and function of miR-148b in lung adenocarcinoma

Objective To investigate the expression and clinical significance of miRNA-148b （ miR-148b） in lung adenocar-cinoma （ LAC） tissues and cell lines. Methods Realtime-PCR was performed to detect the expression of miR-148b between 13 cases of LAC tissues and matched adjacent normal tissues. The expression of miR-148b was also detected in normal lung epithelial HBE cell line, and LAC cell lines H1437, H1975, A549 and PC14/B. The cell line with lowest expression was respectively transfected with miR-148b mimics and miR-148b control. Then, the effect of miR-148b on proliferation, colony formation and invasion ability were ana-lyzed by MTT, low-density cell colony formation and transwell experiments. Results The average relative expression of miR-148b in LAC tissues and adjacent normal tissues were 0. 61±0. 42 and 0. 91±0. 32 （P〈0. 05）. The expression levels of miR-148b in the H1437, H1975, A549, PC14/B cell lines were 0. 42±0. 08,0. 38±0. 02,0. 29±0. 03 and 0. 21±0. 04, lower than that in HBE cell line （ the expression level was set as 1. 00） with significance （ P〈0. 05） . PC14/B cell line was selected for the following experiments. MTT analysis showed that the absorbance value of miR-148b mimics group was much lower than that of miR-148b control group from the 3th day of the test （ P〈0. 05） . As for the low-density cell colony formation analysis, the relative colony formation number of PC14/B cells transfected with miR-148b mimics was 47±8, which was decreased significantly compared with miR-148b control group （set as 100） with significance （ P〈0. 05） . Transwell test showed that there was significant difference in the relative numbers of cells migrated through the basement membrane between miR-148b mimics group （82±22） and miR-148b control group （200±34） with significance （ P〈0. 05） . Conclusion The expression of miR-148b is down-regulated in both LAC tissue and cell lines. It can suppress the cell proliferation,colony formation and invasion ability of PC1