Overexpression of LncRNA AFAP1-AS1 predicts poor prognosis and promotes cells proliferation and invasion in gallbladder cancer.

BACKGROUND: Long non-coding RNA actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been elucidated to be associated with some kinds of human cancers. However, whether lncRNA AFAP1-AS1 implicates in tumor development of gallbladder cancer (GBC) remains largely unknown. This study aims to elucidate the tumorigenic role and regulatory function of lncRNA AFAP1-AS1 in gallbladder cancer.

METHODS: We analyzed lncRNA AFAP1-AS1 expression by quantitative real time PCR (qRT-PCR) in 40 gallbladder cancer tissue and adjacent normal tissues, survival plots were generated by Kaplan-Meier analysis and the log-rank test. The expression levels of transcription factor Twist1 and epithelial-to mesenchymal transition (EMT) makers (E-cadherin and Vimentin) were detected by quantitative real time PCR and western blotting analysis after knockdown of lncRNA AFAP1-AS1.

RESULTS: The expression levels of lncRNA AFAP1-AS1 were significantly elevated in GBC tissues and GBC cell lines. In addition, the expression level of lncRNA AFAP1-AS1 was significantly associated with tumor sizes and the higher expression of lncRNA AFAP1-AS1 was correlated with poor prognosis in GBC patients. Knockdown of LncRNA AFAP1-AS1 suppressed cell growth and invasion in NOZ and GBC-SD cells. Furthermore, we found that knockdown of LncRNA AFAP1-AS1 in GBC cells inhibited EMT by down-regulating the transcription factor Twist1 and Vimentin and up-regulated the E-cadherin.

CONCLUSIONS: Our results suggested lncRNA AFAP1-AS1 was correlated with poor prognosis in GBC patients and lncRNA AFAP1-AS1 might be novel therapeutic target in gallbladder cancer.