Microarray profiling analysis of circular RNAs expression in bladder cancer [lncRNA profiling]

Background: Growing evidence has shown the association of long noncoding RNA/microRNA/mRNA is implicated in tumor initiation, development, and progression. Long noncoding RNA (lncRNA) HAND2-AS1 exhibits anti-cancer effects in diverse cancers. However, the knowledge of HAND-AS1 in bladder cancer remains largely unknown. The present study aims to investigate the effects and mechanisms of HAND-AS1 in bladder cancer progression. Methods: The expression of lncRNA was analyzed by RT2 lncRNA PCR Arrays. The differential expressed lncRNAs were further verified by qRT-PCR. The relationship between lncRNA expression and clinical features was evaluated with Spearman correlation test. Cell proliferation was measured by MTT assay. Cell apoptosis percentage was detected by ANNEXIN V-PI analysis. The promoter activity was illustrated by Luciferase assay, and the change of microRNA and protein was detected by qRT-PCR and western blot, separately. Results: The expression of HAND2-AS1 declined in bladder cancer and correlated with depth of invasion and grades negatively. Restoration of HAND2-AS1 hampered cell growth by provoking cell apoptosis. Furthermore, one of the HAND2-AS1 sponge, miR-146, was found overexpression in bladder cancer tissue and cell lines. Expression of miR-146 related to HAND2-AS1 expression negatively. One of the targeted genes of miR-146, retinoic acid receptor beta (RARB) was downregulated in bladder cancer. In addition, the expression of RARB related to miR-146 negatively. Lost-of-function and gain-of-function experiments were used to identify the mechanisms underlying association of lncRNA HAND2-AS1: miR-146: RARB. miR-146 targeted RARB directly and hindered RARB-mediate apoptosis. However, the hindrance was impaired by HAND2-AS1 notably. Conclusion: HAND2-AS1 diminished miR-146 expression, thereby releasing the suppression of miR-146 on RARB-mediated apoptosis, promoting bladder cancer regression. Three primary patients primary bladder cancer were recruited in the present study. Microarray based LncRNA expression profiles were obtained with Qiagen custom RT2 PCR Arrays.