Department of General Surgery, Nanjing Medical University Affiliated Changzhou No. 2 Hospital, Changzhou, Jiangsu 213164, P.R. China.
Mol Med Rep. 2018 Feb;17(2):2853-2860. doi: 10.3892/mmr.2017.8192. Epub 2017 Dec 5.
Gastric cancer (GC) is one of the most common malignancies in the world. It is essential to develop novel targets and therapeutic approaches for GC, which requires identification of novel functional molecules. WW‑domain containing transcription regulator 1 (WWTR1) may activate many transcriptional factors and exhibit an important role in the development of various tissues in mammals. The results of the present study demonstrated that mRNA and protein levels of WWTR1 are increased in GC tissues and cell lines. The SGC7901 cell line was selected to perform RNA interference (RNAi) targeting WWTR1, and for subsequent study. Compared with control groups (cells without any treatment) and mock groups (cells treated with nonspecific siRNA), cell proliferation of siWWTR1 cells (cells treated with WWTR1 siRNA) was detected using a Cell Counting Kit‑8 assay at 12, 24 and 48 h, and decreased in a time‑dependent manner. Cell cycle and apoptosis status were determined by flow cytometry, and it was demonstrated that G1/S transition was blocked in the cell cycle and apoptosis promoted in siWWTR1 cells, compared with control and mock cells. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to detect the mRNA and protein levels of cell cycle and apoptosis‑associated factors. The expression of Cyclin D1, cancer Myc and B cell lymphoma/leukemia‑2 (Bcl‑2) decreased and Bcl‑2 associated X protein increased significantly in siWWRT1 cells, at the mRNA and protein level, compared with control and mock cells. With the exception of the Hippo pathway, siWWTR1 regulated downstream factors, including mothers against decapentaplegic homolog family member 3 (SMAD3) and inhibitor of DNA binding 1, HLH protein (ID1), HLH protein in the transforming growth factor (TGF)‑β pathway. The expression of asparagine synthetase was decreased whereas ID1, SMAD3 (proteins that participate in intracellular TGF‑β transduction) and betacellulin increased notably in siWWRT1 cells. In conclusion, WWTR1 promotes cell proliferation and inhibits apoptosis of GC cells by regulating cell cycle/apoptosis‑associated factors, and effectors in the TGF‑β pathway.
胃癌（GC）是世界上最常见的恶性肿瘤之一。开发用于 GC 的新型靶点和治疗方法至关重要，这需要鉴定新型功能分子。含 WW 结构域的转录调节剂 1（WWTR1）可激活许多转录因子，并在哺乳动物各种组织的发育中发挥重要作用。本研究结果表明，GC 组织和细胞系中 WWTR1 的 mRNA 和蛋白水平升高。选择 SGC7901 细胞系进行针对 WWTR1 的 RNA 干扰（RNAi），并进行后续研究。与对照组（未经任何处理的细胞）和 mock 组（用非特异性 siRNA 处理的细胞）相比，用 Cell Counting Kit-8 检测 siWWTR1 细胞（用 WWTR1 siRNA 处理的细胞）在 12、24 和 48 h 的细胞增殖情况，发现细胞增殖呈时间依赖性下降。通过流式细胞术检测细胞周期和凋亡状态，结果表明与对照和 mock 细胞相比，siWWTR1 细胞的 G1/S 期转换受阻，促进了细胞凋亡。逆转录-定量聚合酶链反应和蛋白质印迹法检测细胞周期和凋亡相关因子的 mRNA 和蛋白水平。与对照和 mock 细胞相比，siWWTR1 细胞中细胞周期和凋亡相关因子的 mRNA 和蛋白水平均显著下调 Cyclin D1、癌基因 Myc 和 B 细胞淋巴瘤/白血病-2（Bcl-2），上调 Bcl-2 相关 X 蛋白。除了 Hippo 通路外，siWWTR1 还调节下游因子，包括母亲抗 Decapentaplegic 同源物家族成员 3（SMAD3）和 DNA 结合抑制因子 1、转化生长因子（TGF）-β 通路中的 HLH 蛋白 ID1。siWWTR1 细胞中天冬酰胺合成酶表达下调，而 ID1、SMAD3（参与细胞内 TGF-β转导的蛋白）和β细胞素表达显著增加。综上所述，WWTR1 通过调节细胞周期/凋亡相关因子和 TGF-β 通路中的效应物促进 GC 细胞的增殖并抑制其凋亡。
