Department of Pathology, Xing Yuan (4th) Hospital of Yulin, Yulin, Shaanxi 719000, P.R. China.
Department of Gynecology, Ankang Hospital of Traditional Chinese Medicine, Ankang, Shaanxi 725000, P.R. China.
Int J Mol Med. 2020 Feb;45(2):623-633. doi: 10.3892/ijmm.2019.4438. Epub 2019 Dec 23.
The objective of the present study was to investigate the molecular mechanism underlying the role of metformin (Met) in reducing the risk of endometrial hyperplasia (EH). Reverse transcription‑quantitative polymerase chain reaction, western blot and immunohistochemistry (IHC) assays were used to study the effects of Met and tamoxifen on the expression levels of urothelial cancer associated 1 (UCA1), microRNA‑144 (miR‑144) and other factors along the transforming growth factor‑β1 (TGF‑β1)/protein kinase B (AKT) signaling pathway. In addition, MTT and flow cytometry assays were performed to detect the effect of Met on cell proliferation and apoptosis. Tamoxifen treatment increased the weight of the uterus and the level of UCA1, while decreasing the expression of miR‑144. In addition, treatment with tamoxifen (2.0 and 3.5 µg) upregulated the protein expression levels of TGF‑β and p‑AKT, while downregulating the protein expression of active Caspase‑3 in a dose‑dependent manner. By contrast, Met reduced cell viability, promoted cell apoptosis, and reduced the expression levels of UCA1, TGF‑β and p‑AKT, while upregulating the expression of miR‑144 and active Caspase‑3 in a dose‑dependent manner. Furthermore, Met also reduced the weight of uterus. However, tamoxifen and Met did not exert any effect on the protein levels of total AKT and total Caspase‑3. The levels of TGF‑β and p‑AKT proteins in the EH group were much higher when compared with those in the sham group, while Met treatment reduced these protein levels to a certain extent. In addition, the expression of active Caspase‑3 in the EH group was much lower than that in the sham group, while Met treatment increased its level to a certain extent. In conclusion, the current study suggested that Met reduces the risk of EH by reducing the expression levels of UCA1, TGF‑β and p‑AKT, while increasing the levels of miR‑144 and active Caspase‑3 in a dose‑dependent manner.
本研究旨在探讨二甲双胍（Met）降低子宫内膜增生（EH）风险的作用机制。采用逆转录-定量聚合酶链反应、western blot 和免疫组织化学（IHC）检测 Met 和他莫昔芬对尿路上皮癌相关 1（UCA1）、微小 RNA-144（miR-144）及转化生长因子-β1（TGF-β1）/蛋白激酶 B（AKT）信号通路相关其他因子表达水平的影响。此外，采用 MTT 和流式细胞术检测 Met 对细胞增殖和凋亡的影响。他莫昔芬处理增加了子宫重量和 UCA1 水平，同时降低了 miR-144 的表达。此外，他莫昔芬（2.0 和 3.5μg）处理呈剂量依赖性地上调 TGF-β 和 p-AKT 蛋白表达水平，同时下调活性 Caspase-3 蛋白表达水平。相反，Met 降低细胞活力，促进细胞凋亡，并呈剂量依赖性地下调 UCA1、TGF-β 和 p-AKT 表达水平，同时上调 miR-144 和活性 Caspase-3 表达水平。此外，Met 还降低了子宫重量。然而，他莫昔芬和 Met 对总 AKT 和总 Caspase-3 的蛋白水平没有任何影响。EH 组 TGF-β 和 p-AKT 蛋白水平明显高于假手术组，而 Met 处理在一定程度上降低了这些蛋白水平。此外，EH 组活性 Caspase-3 的表达明显低于假手术组，而 Met 处理在一定程度上增加了其水平。综上所述，本研究表明 Met 通过降低 UCA1、TGF-β 和 p-AKT 的表达水平，同时增加 miR-144 和活性 Caspase-3 的水平，从而降低 EH 的发生风险。
