Long noncoding RNA GAS5-AS1 suppresses growth and metastasis of cervical cancer by increasing GAS5 stability

Cervical cancer (CC) is the second most common cancer and the fourth leading cause of cancer-related death in women worldwide. Up to date, only a few of long noncoding RNAs (lncRNAs) have been functionally characterized. Here, we aimed to discover the functional roles of lncRNA GAS5-AS1. The GAS5-AS1 expression in CC tissues was markedly decreased when compared with that in the adjacent normal tissues. The downregulation of GAS5-AS1 was significantly correlated with the advanced FIGO stage, distant metastasis, lymphatic metastasis and poor prognosis in patients with CC. Functionally, GAS5-AS1 drastically reduced CC cell proliferation, migration and invasion in vitro, and remarkably suppressed CC tumorigenicity and metastasis in vivo. Mechanistically, it was found that GAS5-AS1 interacted with the tumor suppressor GAS5, and increased its stability by interacting with RNA demethylase ALKBH5 and decreasing GAS5 N6-methyladenosine (m(6)A) modification. Moreover, it was shown that m(6)A-mediated GAS5 RNA degradation relied on the m(6)A reader protein YTHDF2-dependent pathway. Our findings reveal an important mechanism of epigenetic alteration in CC carcinogenesis and metastasis.