MicroRNA-149-3p expression correlates with outcomes of adrenocortical tumor patients and affects proliferation and cell cycle progression of H295A adrenocortical cancer cell line

Pediatric adrenocortical tumor (ACT) is a rare and aggressive neoplasm, with incidence in southern and southeastern Brazil 10–15 times higher than worldwide. Although microRNAs (miRNAs) have been reported to act as tumor suppressors or oncogenes in several cancers, the role of miR-149-3p in ACT remains unknown. In this study, we evaluated the expression of miR-149-3p in 67 pediatric ACT samples and 19 non-neoplastic adrenal tissues. The overexpression of miR-149-3p was induced in H295A cell line, and cell viability, proliferation, colony formation, and cell cycle were assessed by in miR-149-3p mimic or mimic control. In silico analysis were used to predict miR-149-3p putative target genes. CDKN1A expression at the mRNA and protein levels was evaluated by qRT-PCR and western blot, respectively. Higher miR-149-3p expression was associated with unfavorable ACT outcomes. Compared to the mimic control, miR-149-3p overexpression increased cell viability and colony formation, and affected cell cycle progression. Also, we identified CDKN1A as a potential miR-149-3p target gene, with decreased expression at both the gene and protein levels in miR-149-3p mimic cells. Collectively, these findings suggest that miR-149-3p promotes H295A cell viability by downregulating CDKN1A and provide evidence that miR-149-3p may be useful as a novel therapeutic target for pediatric ACT