Long noncoding RNA HCG22 suppresses proliferation and metastasis of bladder cancer cells by regulation of PTBP1

Multifarious biological functions of long noncoding RNAs (lncRNAs) have been reported in various cancers including bladder cancer (BCa). This study aims to determine the biological role of a certain lncRNA in BCa. Consistent with the data of The Cancer Genome Atlas database, it was validated that lncRNA HLA complex group 22 (HCG22) was weakly expressed in BCa samples and lowly expressed HCG22 was closely correlated with low overall survival of the BCa patient. To verify the role of HCG22 in BCa progression, functional experiments were carried out in two representative BCa cells (J82 and T24) and the negative effects of HCG22 expression on the cell proliferation, migration, and epithelial-mesenchymal transition were identified. Mechanistically, polypyrimidine tract-binding protein 1 (PTBP1), which was highly expressed in BCa tissues and cell lines, was negatively regulated by HCG22 and the PTBP1-mediated Warburg effect was also obstructed by HCG22. Furthermore, HCG22 modulated the expression of PTBP1 through destabilizing human antigen R (HuR). And functional rescue assays confirmed that HCG22 functioned in bladder cancer through downregulating PTBP1. In conclusion, the present study revealed that HCG22 inhibited BCa progression via the HuR/PTBP1 axis, opening new prospects for potent therapeutic regimens for BCa patients.