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.