Long noncoding RNA MAPKAPK5-AS1 promotes colorectal cancer proliferation by partly silencing p21 expression.

Colorectal cancer (CRC) is the third most common malignancy in the world, and long noncoding RNA (lncRNA) plays a critical role in carcinogenesis. Here, we report a novel lncRNA, MAPKAPK5-AS1, that acts as a critical oncogene in CRC. In addition, we attempted to explore the functions of MAPKAPK5-AS1 on tumor progression in vitro and in vivo. Quantitative RT-PCR was used to examine the expression of MAPKAPK5-AS1 in CRC tissues and cells. Expression of MAPKAPK5-AS1 was significantly upregulated in 50 CRC tissues, and increased expression of MAPKAPK5-AS1 was found to be associated with greater tumor size and advanced pathological stage in CRC patients. Knockdown of MAPKAPK5-AS1 significantly inhibited proliferation and caused apoptosis in CRC cells. We also found that p21 is a target of MAPKAPK5-AS1. In addition, we are the first to report that MAPKAPK5-AS1 plays a carcinogenic role in CRC. MAPKAPK5-AS1 is a novel prognostic biomarker and a potential therapeutic candidate for CRC cancer.