Homeobox A5 activates p53 pathway to inhibit proliferation and promote apoptosis of adrenocortical carcinoma cells by inducing Aldo-Keto reductase family 1 member B10 expression.

Aldo-Keto Reductase Family 1 Member B10 (AKR1B10) and Homeobox A5 (HOXA5) are both down-regulated in adrenocortical carcinoma (ACC), and HOXA5 is predicted to bind to the promoter of AKR1B10. We aimed to investigate whether HOXA5 could bind to AKR1B10 to regulate ACC cells proliferation and apoptosis. The expression of AKR1B10 and HOXA5 in ACC patients and the relationship of their expression between ACC prognosis were evaluated by searching database. Then, NCI-H295R cells were overexpressed to detect the alteration of cell proliferation, apoptosis and the expression of p53 and p21 proteins. The interaction between AKR1B10 and HOXA5 was validated by luciferase report and chromatin immunoprecipitation. Finally, NCI-H295R cells were silenced with HOXA5 in the presence of AKR1B10 overexpression, and then cell proliferation and apoptosis were also assessed. Results revealed that AKR1B10 and HOXA5 are down-regulated in ACC patients and the low expression of it is correlated with low percent of overall survival (OS) and disease free survival (DFS). Compared with Y1 cells, SW-13 and NCI-H295R cells exerted lower expression of AKR1B10 and HOXA5. AKR1B10 significantly inhibited cell viability, colony formation and expression of Ki67 and PCNA, but promoted apoptosis and expression of p53 and p21 in NCI-H295R cells. HOXA5 could interact with AKR1B10 and enhance AKR1B10 expression. Furthermore, HOXA5 knockdown obviously blocked the effect of AKR1B10 overexpression on NCI-H295R cells proliferation and apoptosis. In conclusion, HOXA5 could bind to AKR1B10 promotor to increase its expression, activate p53 signaling, thereby inhibiting proliferation and promoting apoptosis of ACC cells.