ABSTRACT
BACKGROUND AND STUDY AIMS: Previous studies have suggested that lncRNAs impact cancer progression. The lncRNA AC125611.3 (also referred to as RP11-161H23.5) is highly expressed in colon cancer but rarely studied; understanding its regulation may provide novel insights on treating colon cancer. MATERIALS AND METHODS: qRT-PCR was performed to quantify RNAs. CCK-8 and EdU assays were performed to assess cell proliferation. Western blot analysis was used to detect levels of proteins related to cell apoptosis and EMT. Wound healing assay and Transwell invasion assay were conducted to evaluate cell migratory and invasive capabilities, respectively. Luciferase reporter assay, RIP assay, and pull-down assay were used to verify RNA-RNA and RNA-protein interactions. RESULTS: AC125611.3 was highly overexpressed in colon cancer cells. AC125611.3 depletion curbed cell proliferative, invasive, migratory, and EMT processes while enhancing apoptosis. Furthermore, AC125611.3 activated the Wnt signaling pathway in colon cancer cells by regulating catenin beta-1 (CTNNB1). Moreover, AC125611.3 recruited dyskeratosis congenita 1 (DKC1) to stabilize CTNNB1. CONCLUSION: AC125611.3 recruits DKC1 to stabilize CTNNB1 and activate Wnt signaling, thereby promoting the progression of colon cancer.
Subject(s)
Colonic Neoplasms , Dyskeratosis Congenita , RNA, Long Noncoding , Humans , Cell Line, Tumor , Dyskeratosis Congenita/genetics , Colonic Neoplasms/genetics , Colonic Neoplasms/metabolism , Wnt Signaling Pathway/genetics , RNA, Long Noncoding/genetics , Gene Expression Regulation, Neoplastic , Nuclear Proteins/genetics , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , beta Catenin/genetics , beta Catenin/metabolismABSTRACT
PURPOSE: The purpose of this study was to explore the possible role and mechanism of LINC00538 in the pathogenesis of colon cancer. METHODS: The expression levels of LINC00538 in 70 pairs of colon cancer tissue samples and adjacent ones were examined by qRT-PCR, and survival analysis of patients was performed according to the result. Meanwhile, colon cancer cell lines were screened. In addition, LINC00538 siRNA was transfected into colon cancer cells using liposome method, and then cell proliferation and cell cycle were examined by CCK8 and EDU assays, while cell apoptosis was detected by flow cytometry. Finally, the mechanism of LINC00538 in colon cancer was further explored by RNA-binding protein immunoprecipitation and chromatin immunoprecipitation. RESULTS: The expression of LINC00538 in colon cancer tissues was remarkably higher than that in normal ones, and the overall survival of patients with colon cancer was negatively correlated with the expression of LINC00538. After transfection of LINC00538 siRNA, the proliferation rate of colon cancer cell lines including HCT116 and RKO cells was weakened, the S phase of the cell cycle was shortened, while the cell apoptosis was elevated. In addition, further mechanism studies demonstrated that LINC00538 can bind to EZH2 and inhibit the expression of NKD2, thereby regulating the proliferation and apoptosis of colon cancer cells. CONCLUSIONS: This study demonstrated for the first time that LINC00538 was highly expressed in colon cancer and was associated with poor prognosis of patients. Knockdown of LINC00538 in colon cancer cell lines was able to inhibit the cell proliferation and cell cycle, while it promoted the apoptosis. It's mechanism of participating in the development of colon cancer may be through the down-regulation of NKD2 and the regulation of EZH2.
