Choi Yoon Sung, Lee Kyung Eun
Department of Clinical Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Korea.
J Cancer Prev. 2015 Dec;20(4):268-74. doi: 10.15430/JCP.2015.20.4.268. Epub 2015 Dec 30.
A microRNA, miR-34a, plays a key role in inhibiting cellular transformation and carcinogenesis by controlling cell cycle regulation and cell proliferation in various human tumors. However, miR-34a has rarely been reported in endometrial cancer research in Korea. This study was undertaken to analyze miR-34a expression in simple endometrial hyperplasia and endometrial cancer, and to evaluate the relationship between expression of miR-34a and p16 and Ki-67 proteins in endometrial cancers.
A retrospective study was carried out on 66 formalin-fixed, paraffin-embedded tissues with simple endometrial hyperplasia (31 cases) and endometrial cancer (35 cases) patients. These were analyzed for miR-34a expression by quantitative real-time PCR, and the expression of p16 and Ki-67 proteins in endometrial cancers was evaluated by immunohistochemistry.
The miR-34a expression level was lower in endometrial cancer tissues (-0.71 ± 3.90) than in simple endometrial hyperplasia tissues (2.68 ± 8.62). The endometrial hyperplasia tissues showed underexpression of miR-34a in 13 of the 31 cases (41.9%) while the endometrial cancer tissues showed underexpression of miR-34a in 24 of 35 cases (68.6%). Thus, miR-34a was significantly underexpressed in endometrial cancer tissues when compared endometrial hyperplasia tissues (P = 0.046). Overexpression of p16 was detected in 25 (71.4%) and Ki-67 immunoreactivity was detected in 27 (77.1%) of the 35 endometrial cancers. Although not statistically significant, the frequency of p16 and Ki-67 overexpression tended to be lower in the cases with miR-34a underexpression than in cases with miR-34a overexpression.
These findings suggest that underexpression of miR-34a might be involved in endometrial carcinogenesis. Further studies are needed to define the relationship between miR-34a expression and tissue specific protein expression.
微小RNA miR-34a通过控制多种人类肿瘤的细胞周期调控和细胞增殖，在抑制细胞转化和致癌过程中发挥关键作用。然而，在韩国的子宫内膜癌研究中，miR-34a鲜有报道。本研究旨在分析miR-34a在单纯性子宫内膜增生和子宫内膜癌中的表达情况，并评估子宫内膜癌中miR-34a表达与p16和Ki-67蛋白表达之间的关系。
对66例经福尔马林固定、石蜡包埋的组织进行回顾性研究，其中包括单纯性子宫内膜增生患者31例和子宫内膜癌患者35例。通过定量实时PCR分析这些组织中miR-34a的表达情况，并通过免疫组织化学评估子宫内膜癌中p16和Ki-67蛋白的表达。
子宫内膜癌组织中miR-34a的表达水平（-0.71±3.90）低于单纯性子宫内膜增生组织（2.68±8.62）。31例单纯性子宫内膜增生组织中有13例（41.9%）miR-34a表达不足，而35例子宫内膜癌组织中有24例（68.6%）miR-34a表达不足。因此，与单纯性子宫内膜增生组织相比，子宫内膜癌组织中miR-34a明显表达不足（P = 0.046）。在35例子宫内膜癌中，25例（71.4%）检测到p16过表达，27例（77.1%）检测到Ki-67免疫反应性。尽管无统计学意义，但miR-34a表达不足的病例中p16和Ki-67过表达的频率往往低于miR-34a过表达的病例。
这些发现表明，miR-34a表达不足可能参与子宫内膜癌的发生。需要进一步研究来确定miR-34a表达与组织特异性蛋白表达之间的关系。
