Long non-coding RNA DLX6-AS1 facilitates bladder cancer progression through modulating miR-195-5p/VEGFA signaling pathway

In this study, we aim at investigating the expression and regulation role of long non-coding RNA (lncRNA) DLX6-AS1 in bladder cancer (BC). DLX6-AS1 was highly expressed in BC tissues and significant negative correlation with the 5-year survival in the BC patients. The results showed that the proliferation, migration and invasion activities of BC cells were promoted by DLX6-AS1 overexpression, while cell apoptosis was repressed. However, knockdown DLX6-AS1 presented an opposite regulatory effect, and DLX6-AS1 knockdown delayed tumor in vivo. The potential target of DLX6-AS1 in BC was predicted and verified by RIP, RNA pull-down, and dual-luciferase reporter assays as miR-195-5p. The results showed that miR-195-5p was down-regulated in BC tissues, the expression of which was significantly negative correlated with DLX6-AS1 expression. In addition, the results also showed that miR-195-5p targeted and down-regulated the VEGFA. Knockdown of DLX6-AS1 up-regulated miR-195-5p expression and down-regulated VEGFA expression. Moreover, down-regulation of VEGFA expression caused by DLX6-AS1 inhibited phosphorylation of Raf-1, MEK1/2, and ERK1/2, while miR-195-5p inhibitors abolished the effect of silencing DLX6-AS1 expression. Our study demonstrated that DLX6-AS1 played an oncogenic role in BC through miR-195-5p-mediated VEGFA/Ras/Raf/MEK/ERK pathway.