微小RNA-218在胃癌中的表达与作用

Reduced expression of miR-218 and its significance in gastric cancer

目的检测微小RNA-218（miR-218）在胃癌组织中的表达水平及其功能，探讨miR-218在胃癌发生、发展中的作用和意义。方法采用发夹状引物的逆转录聚合酶链反应（RT—PCR）技术，检测20例非贲门胃癌组织和正常胃黏膜组织中miR-218的表达水平。通过转染不同的外源性分子，改变胃上皮AGS细胞miR-218的表达水平，检测miR-218对细胞增殖、凋亡、细胞周期和侵袭能力的影响。结果与正常胃黏膜组织相比，miR-218在胃癌组织中呈低表达（P〈0．01），其比值平均为0．19（范围0．01～0．70）。流式细胞技术检测结果显示，转染miR-218前体的AGS细胞凋亡率（21．6％）明显增加，与转染阴性参照（10．4％）的AGS细胞差异有统计学意义（P〈0．05）。与转染阴性参照比较，转染miR-218前体可明显抑制细胞增殖（P〈0．01）。Transwell试验证实，AGS细胞在转染miR-218前体后，细胞侵袭能力明显减弱（P〈0．05）。结论在胃癌组织中，miR-218的表达降低，miR-218具有促进细胞凋亡、抑制细胞增殖和侵袭的功能。

Objective To investigate the expression and function of miR-218 in gastric cancer. Methods miR-218 levels were evaluated in 20 non-cardia gastric cancer tissues using TaqMan stem-loop real-time PCR analysis. Prc-miR-218 and anti-miR-218 inhibitor were used to change the miR-218 expression level and examine its effects on cell proliferation, apoptosis, cell cycle and cell invasion. Results Comparing with the corresponding normal tissues, miR-218 expression was significantly reduced in the gastric cancer tissue （P 〈0.01 ）. Forced expression of miR-218 increased apoptosis in AGS cells. The proportion of apoptosis cells induced by transfection of pre-miR-218 was greater than that induced by control （21.6% vs. 10.4% , P =0. 032）. Pre-miR-218 resulted in a significantly decreased cell growth activity （P 〈0.01 ） and cell invasion （ P 〈 0.05） of AGS cells compared with that of the control. Conclusion miR-218 expression is reduced in gastric cancer, miR-218 may function as a tumor suppressor in gastric carcinoma.