Shen Lei, Zhang Pingping, Wang Jianbing, Ji Peng
Department of Oncology, The Third People's Hospital of Hefei, Hefei, Anhui 230051, P.R. China.
Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, P.R. China.
Exp Ther Med. 2020 Nov;20(5):113. doi: 10.3892/etm.2020.9241. Epub 2020 Sep 18.
Gastric cancer is one of the most common types of malignancy worldwide. Tac2-N (TC2N) has been reported to serve as either an oncogene or tumor suppressor in numerous different types of cancer; however, the role of TC2N in gastric cancer remains poorly understood. The present study aimed to investigate the role of TC2N in gastric cancer and reveal its regulatory mechanism. A Cell Counting Kit-8 assay was used to analyze the cell proliferation rate, while wound healing and Transwell Matrigel assays were performed to determine the cell migratory and invasive abilities, respectively. Cell cycle distribution was determined by flow cytometric analysis, and the expression levels of TC2N, P-glycoprotein (P-gp), cyclin D1, CDK4, cyclin E1, MMP2, MMP9 and N-Myc downstream regulated gene 1 were analyzed using reverse transcription-quantitative PCR or western blotting. Bioinformatics analysis revealed a high expression of TC2N in patients with gastric cancer. The experimental results revealed that TC2N expression levels were significantly unregulated in gastric cancer cell lines. The knockdown of TC2N in AGS cells significantly inhibited the cell proliferation rate and induced cell cycle arrest at the G0/G1 phase, while downregulating cyclin E1, cyclin D1 and CDK4 expression levels. The knockdown of TC2N also inhibited cell migration and invasion. Furthermore, the knockdown of TC2N improved the sensitivity of AGS cells to cisplatin, paclitaxel and 5-fluorouracil, and downregulated the protein expression levels of P-gp. By contrast, TC2N overexpression exerted the opposite effects in AGS cells. In conclusion, the findings of the present study indicated that the genetic knockdown of TC2N may inhibit cell proliferation, migration and invasion, while inducing cell cycle arrest in the G1/S phase and reversing the drug resistance of AGS cells, which may be partly through inhibiting P-gp expression levels. Thus, TC2N may serve as a novel diagnostic marker and therapeutic target for patients with gastric cancer.
胃癌是全球最常见的恶性肿瘤类型之一。据报道，Tac2-N（TC2N）在多种不同类型的癌症中既作为癌基因又作为肿瘤抑制因子发挥作用；然而，TC2N在胃癌中的作用仍知之甚少。本研究旨在探讨TC2N在胃癌中的作用并揭示其调控机制。使用细胞计数试剂盒-8分析细胞增殖率，同时分别进行伤口愈合试验和Transwell基质胶试验以确定细胞迁移和侵袭能力。通过流式细胞术分析确定细胞周期分布，并使用逆转录定量PCR或蛋白质印迹法分析TC2N、P-糖蛋白（P-gp）、细胞周期蛋白D1、细胞周期蛋白依赖性激酶4（CDK4）、细胞周期蛋白E1、基质金属蛋白酶2（MMP2）、基质金属蛋白酶9（MMP9）和N-Myc下游调节基因1的表达水平。生物信息学分析显示胃癌患者中TC2N高表达。实验结果表明，胃癌细胞系中TC2N表达水平明显失调。在AGS细胞中敲低TC2N可显著抑制细胞增殖率并诱导细胞周期停滞在G₀/G₁期，同时下调细胞周期蛋白E1、细胞周期蛋白D1和CDK4的表达水平。敲低TC2N也抑制细胞迁移和侵袭。此外，敲低TC2N提高了AGS细胞对顺铂、紫杉醇和5-氟尿嘧啶的敏感性，并下调了P-gp的蛋白表达水平。相比之下，TC2N过表达在AGS细胞中产生相反的作用。总之，本研究结果表明，基因敲低TC2N可能抑制细胞增殖、迁移和侵袭，同时诱导细胞周期停滞在G₁/S期并逆转AGS细胞的耐药性，这可能部分是通过抑制P-gp表达水平实现的。因此，TC2N可能作为胃癌患者的一种新型诊断标志物和治疗靶点。
