Overexpression of lncRNA AFAP1-AS1 correlates with poor prognosis and promotes tumorigenesis in colorectal cancer.

Accumulating evidence has shown that long non-coding RNAs (lncRNAs) are emerging as key molecules in human malignancies. The lncRNA actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) was recently found deregulated in several cancers. However, its expression pattern, clinical performance and functional roles in colorectal cancer (CRC) had not been addressed. In this study, we found that AFAP1-AS1 was aberrantly over-expressed in CRC tissues and closely correlated with tumor size, TNM stage and distant metastasis. Kaplan-Meier analysis indicated that patients with high level of AFAP1-AS1 expression had poorer overall survival (OS) and disease-free survival (DFS). Univariate and multivariable Cox regression analyses further identified that up-regulated AFAP1-AS1 might act as an independent prognostic factor for CRC patients. Moreover, AFAP1-AS1 depletion resulted in the inhibition of CRC cell proliferation and colony formation. In addition, AFAP1-AS1 knockdown induced G0/G1 cell cycle arrest in CRC cells. Taken together, our findings indicate that AFAP1-AS1 is significantly up-regulated in CRC, which may act as an oncogene and correlate with tumor malignant progression and poor prognosis of CRC. This study may shed a new light on better understanding the pathogenesis of CRC. Moreover, AFAP1-AS1 also may be a promising diagnostic and therapeutic target for this deadly disease.