LncRNA CASC15 upregulates cyclin D1 by downregulating miR-365 in laryngeal squamous cell carcinoma to promote cell proliferation

BACKGROUND: This study investigated the role of lncRNA CASC15 in laryngeal squamous cell carcinoma (LSCC). METHODS: This study included 58 LSCC patients. Both tumor (LSCC) and adjacent (within 3 cm around tumors) non-tumor tissues from 3 different sites of each patient were collected. CCK-8 assay was used to determine cell proliferation. The expression levels of proteins and mRNAs were determined by Western blotting analysis and qRT-PCRs, respectively. RESULTS: CASC15 was upregulated in LSCC and high expression levels of CASC15 predicted poor survival. In LSCC tissues, CASC15 was negatively correlated with miR-365 but positively correlated with cyclin D1. In LSCC cells, overexpression of CASC15 resulted in downregulation of miR-365 and upregulation of cyclin D1. Overexpression of miR-365 did not affect the expression of CASC15 but downregulated cyclin D1. Overexpression of Cyclin D1 did not affect the expression of miR-365 and CASC15. Overexpression of CASC15 and cyclin D1 led to promoted, while overexpression of miR-365 led to inhibited LSCC cell proliferation. In addition, overexpression of miR-365 reduced the effects of overexpression of CASC15. CONCLUSION: Therefore, CASC15 upregulates cyclin D1 by downregulating miR-365 in LSCC to promote cell proliferation.