LncRNA TDRG1 functions as an oncogene in cervical cancer through sponging miR-330-5p to modulate ELK1 expression

摘要

OBJECTIVE: Increasing evidence shows that long non-coding RNAs (lncRNAs) play important roles in the development and progression of human carcinoma. TDRG1 was a recently identified lncRNA which was reported to promote the progression of several carcinomas. However, its function in cervical cancer remains unknown. MATERIALS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay was performed to determine the mRNA expression. siRNA for lncRNA TDRG1, miR-330-5p, and the corresponding negative control were conducted. The cell function analysis was evaluated by CCK-8 assay, colony formation assay, transwell assay, scratch assay, and flow cytometry analysis. RNA-binding protein immunoprecipitation (RIP), Dual-Luciferase reporter assay, and RNA pull-down assay were used to determine the potential targets of TDRG1 or miR-330-5p. Western blot and Immunohistochemistry (IHC) analysis were used to examine the protein expression. The effect of TDRG1 on tumor growth was evaluated in vivo. RESULTS: LncRNA TDRG1 expression was notably increased in cervical cancer tissues and cancer cells. LncRNA TDRG1 promoted the proliferation and migration of cervical cancer cells. Mechanism investigation suggested that lncRNA TDRG1 up-regulated the expression of ELK1 by acting as a competing endogenous RNA (CeRNA) of miR-330-5p. Rescue experiments indicated that miR-330-5p-inhibitor reversed the si-TDRG1-induced cell activity changes. This in vivo study proved that the down-regulation of lncRNA TDRG1 inhibited cervical tumor growth by regulating miR-330-5p/ELK1. CONCLUSIONS: The present study reveals that lncRNA TDRG1 promotes cervical cancer progression by acting as a CeRNA of miR-330-5p to modulate the expression levels of ELK1 and may be explored as a novel target for developing therapeutic strategies for the treatment of cervical cancer.