Background: Colorectal cancer is a heterogeneous disease with complex genetic and epigenetic changes. LncRNA has recently been regarded as the biomarker in cancers. Novel biomarkers in colon cancer need to be identified.
Purpose: The objective of this study was to identify the differentially expressed lncRNAs between colon cancer tissue and adjacent tissue, as well as to explore its biological functions.
Patients and methods: There were 130 colon cancer patients included in this study. Of them, 6 colon cancer samples and 3 normal samples were selected for microarray profiling. Another 121 colon cancer samples with complete clinical information were used for immunohistochemical assay and survival analysis. Microarray analysis was performed to determine the differentially expressed lncRNAs between colon cancer tissue and adjacent tissue. Gain-of-function experiments was conducted in vitro and in vivo. In situ hybridization and survival analysis were applied to determine the prognostic impact on survival.
Results: LncRNA XIRP2-AS1 was significantly less expressed in colon cancer tissue. XIRP2-AS1 was remarkably downregulated in colon cancer tissues and cell lines. Functionally, XIRP2-AS1 could inhibit the proliferation and invasion ability of colon cancer cells in vitro and in vivo. Clinical sample analysis showed that XIRP2-AS1 had a favorable impact on the overall survival and progression free survival of patients with colon cancer. miR-182 was validated as the target of XIRP2-AS1 according to luciferase reporter assays, RNA immunoprecipitation and RNA pull down.
Conclusions: Our results suggested that XIRP2-AS1 may act as a favorable biomarker for patients with colon cancer.
Keywords: XIRP2-AS1; colon cancer; invasion; proliferation; survival.