Department of General Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.
Oncol Rep. 2018 Oct;40(4):2067-2078. doi: 10.3892/or.2018.6636. Epub 2018 Aug 7.
Colorectal cancer (CRC) is among the most common malignancies of the digestive system. Dysregulation of miRNAs and the farnesoid X receptor (FXR) are involved in the progression of CRC. In the present study, the effects of FXR and miR‑135A1 in CRC were evaluated. Reverse transcription quantitative‑polymerase chain reaction (RT‑qPCR) was used to examine the expression of miR‑135A1 in patient CRC tissues and adjacent non‑tumor tissues, as well as cell lines. The association between miR‑135A1 and clinical characteristics of patients with CRC was also investigated. RT‑qPCR and western blotting were used to evaluate the expression of miR‑135A1 targets. Regulation of cyclin G2 (CCNG2) by miR‑135A1was confirmed using luciferase assays. The biological effects of miR‑135A1 were assessed in transfected and untransfected CRC cell lines using colony formation assays, cell‑cycle analysis by flow cytometry, and CCK‑8 assays. miR‑135A1 was upregulated in CRC specimens and cell lines. miR‑135A1 expression was strongly associated with poor cell differentiation, high expression of carbohydrate antigen (CA)125, CA199, carcinoembryonic antigen and survival rate of patients with CRC. Expression of CCNG2 was downregulated in CRC patients and cell lines, and was further demonstrated to be among the downstream targets of miR‑135A1. The present study indicated that inhibition of miR‑135A1 expression leads to cell cycle arrest and inhibition of proliferation of CRC cells via increasing CCNG2 expression. In the present study, activation of FXR by GW4064 increased CCNG2 expression via suppression of miR‑135A1 expression, and the FXR/miR‑135A1/CCNG2 axis was demonstrated to be involved in mediating cell proliferation. In conclusion, activation of FXR by GW4064 suppresses cell proliferation and causes cell cycle arrest in CRC, and the miR‑135A1/CCNG2 pathway was suggested to be involved in this step.
结直肠癌（CRC）是消化系统最常见的恶性肿瘤之一。miRNA 和法尼醇 X 受体（FXR）的失调参与了结直肠癌的进展。在本研究中，评估了 FXR 和 miR-135A1 在 CRC 中的作用。逆转录定量聚合酶链反应（RT-qPCR）用于检测患者 CRC 组织和相邻非肿瘤组织以及细胞系中 miR-135A1 的表达。还研究了 miR-135A1 与 CRC 患者临床特征之间的关联。RT-qPCR 和 Western blot 用于评估 miR-135A1 靶标的表达。使用荧光素酶测定法证实了 miR-135A1 对细胞周期 G2（CCNG2）的调节作用。使用集落形成测定、流式细胞术的细胞周期分析和 CCK-8 测定评估转染和未转染 CRC 细胞系中 miR-135A1 的生物学效应。miR-135A1 在 CRC 标本和细胞系中上调。miR-135A1 的表达与患者 CRC 中细胞分化不良、碳水化合物抗原（CA）125、CA199、癌胚抗原表达高和生存率差强烈相关。CCNG2 在 CRC 患者和细胞系中的表达下调，并进一步证明是 miR-135A1 的下游靶标之一。本研究表明，抑制 miR-135A1 的表达通过增加 CCNG2 的表达导致 CRC 细胞的细胞周期停滞和增殖抑制。在本研究中，GW4064 通过抑制 miR-135A1 的表达激活 FXR，从而增加 CCNG2 的表达，并且证明 FXR/miR-135A1/CCNG2 轴参与介导细胞增殖。总之，GW4064 激活 FXR 可抑制 CRC 中的细胞增殖并导致细胞周期停滞，并且提示 miR-135A1/CCNG2 通路参与这一步骤。
