Luo Zhuhe, Chen Ruijun, Hu Shen, Huang Xibin, Huang Zhenyi
Department of Pharmacy, Huizhou Central People's Hospital, Huizhou, Guangdong 516001, P.R. China.
Department of Gastrointestinal Surgery, Huizhou Central People's Hospital, Huizhou, Guangdong 516001, P.R. China.
Oncol Lett. 2022 Jun 24;24(2):280. doi: 10.3892/ol.2022.13400. eCollection 2022 Aug.
Drug resistance in tumors is a major issue, limiting the curative efficacy of currently available cancer chemotherapeutics. 5-Fluorouracil (5-FU) is a commonly applied therapeutic drug in colon cancer patient regimens; however, the majority of patients develop resistance to 5-FU in the later stages of the disease, rendering this chemotherapy ineffective. Drug resistance is the main factor underlying the poor prognosis of patients with colon cancer. In recent years, a number of studies have confirmed that long non-coding (lnc)RNAs may play vital roles in tumor resistance. In the present study, the Gene Expression Omnibus (GEO) and lncRNADisease2 databases were screened for colon cancer-associated expression patterns of lncRNA plasmacytoma variant translocation 1 (PVT1). Subsequently, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect changes in PVT1 expression in resistant cell lines, and a Cell Counting Kit-8 (CCK-8) assay kit was used to assess the effects of PVT1 knockdown on the half maximal inhibitory concentrations of parental and 5-FU-resistant HCT116 cells. Subsequently, CCK-8, clone formation, and flow cytometric assays were performed to investigate the effects of PVT1 knockdown on the sensitivity of HCT116-5FU-resistant cells to 5-FU. Dual-luciferase assay, RNA pull-down and RNA immunoprecipitation assays verified the interactive regulation of PVT1, miR-486-5p and cyclin dependent kinase 4 (CDK4). PVT1 was highly expressed in HCT116-5FU-resistant cells, as compared to its expression in HCT116 parental cells. PVT1 knockdown significantly reduced the resistance of HCT116-5FU-resistant cells to 5-FU. In addition, PVT1 upregulated CDK4 expression by adsorbing miR-486-5p; however, CDK4 overexpression restored the effects of miR-486-5p inhibition on HCT116-5-FU-resistant cells. Additionally, PVT1 knockdown partially rescued CDK4 overexpression in HCT116-5-FU-resistant cells. On the whole, the findings of the present study suggest that PVT1 promotes the resistance of colon cancer cells to 5-FU by regulating the miR-486-5p/CDK4 axis. Therefore, PVT1 may prove to be a potential target for counteracting resistance to 5-FU in colon cancer therapy.
肿瘤中的耐药性是一个主要问题,限制了目前可用的癌症化疗药物的疗效。5-氟尿嘧啶(5-FU)是结肠癌患者治疗方案中常用的治疗药物;然而,大多数患者在疾病后期对5-FU产生耐药性,导致这种化疗无效。耐药性是结肠癌患者预后不良的主要因素。近年来,多项研究证实长链非编码(lnc)RNA可能在肿瘤耐药中发挥重要作用。在本研究中,对基因表达综合数据库(GEO)和lncRNADisease2数据库进行筛选,以寻找与结肠癌相关的lncRNA浆细胞瘤变体易位1(PVT1)的表达模式。随后,采用逆转录定量聚合酶链反应(RT-qPCR)检测耐药细胞系中PVT1表达的变化,并使用细胞计数试剂盒-8(CCK-8)检测试剂盒评估敲低PVT1对亲本和5-FU耐药HCT116细胞半数最大抑制浓度的影响。随后,进行CCK-8、克隆形成和流式细胞术检测,以研究敲低PVT1对HCT116-5FU耐药细胞对5-FU敏感性的影响。双荧光素酶检测、RNA下拉和RNA免疫沉淀检测验证了PVT1、miR-486-5p和细胞周期蛋白依赖性激酶4(CDK4)之间的相互调控。与HCT116亲本细胞中的表达相比,PVT1在HCT116-5FU耐药细胞中高表达。敲低PVT1显著降低了HCT116-5FU耐药细胞对5-FU的耐药性。此外,PVT1通过吸附miR-486-5p上调CDK4的表达;然而,CDK4过表达恢复了miR-486-5p抑制对HCT116-5-FU耐药细胞的影响。此外,敲低PVT1部分挽救了HCT116-5-FU耐药细胞中CDK4的过表达。总体而言,本研究结果表明,PVT1通过调节miR-486-5p/CDK4轴促进结肠癌细胞对5-FU的耐药性。因此,PVT1可能被证明是克服结肠癌治疗中对5-FU耐药性的潜在靶点。