LncRNA LINC00461 Promotes Colorectal Cancer Progression via miRNA-323b-3p/NFIB Axis

BACKGROUND: LncRNA LINC00461 has been reported to play crucial regulatory roles in a variety of biological processes, including cell migration, cell invasion and cancer progression. However, its biological role in colorectal cancer (CRC) is completely unknown. The aim of our study was to explore the function of LINC00461 on CRC cells and the underlying mechanism. MATERIALS AND METHODS: CRC tumor tissues and cell lines derived from hospital and corporation. The expression level of LINC00461 in CRC tissues and cell lines were analyzed by quantitative real-time PCR (qRT-PCR). The effect of LINC00461 on cell proliferation, colony formation, migration and invasion were detected by CCK-8 assay, colony formation and transwell assay, respectively. In addition, cell apoptosis was analyzed by flow cytometry, and the role of LINC00461 on tumor growth was investigated by tumor xenografts in nude mice. The targets of LINC00461 were predicted by starBase v3.0 and confirmed by a dual-luciferase reporter system. The expression level of transcription factors of nuclear factor I B (NFIB), p21 and CDK2 was determined by Western blot or qRT-PCR. The NFIB expression levels in CRC tissues and mice tumors were analyzed by immunofluorescence assay (IHC). RESULTS: We found that the expression of LINC00461 was significantly overexpressed in CRC tissues and different cell lines, and the high level of LINC00461 expression was associated with poor overall survival. Downregulation of LINC00461 expression significantly suppressed the proliferation, migration and invasion of CRC cells and promoted cell apoptosis. We also found that LINC00461 could directly interact with miR-323b-3p. In addition, LINC00461 significantly increased the expression NFIB and CDK2, but, p21 was inhibited. Finally, we found that the growth of tumors in nude mice was suppressed upon LINC00461 deletion. CONCLUSION: We demonstrated that LINC00461 may play an oncogenic role in CRC cells through NFIB signaling pathway by targeting miR-323b-3p. Our report showed that LINC00461 may be a prognostic biomarker and candidate therapeutic target for CRC.