MicroRNA-193b-3p represses neuroblastoma cell growth via downregulation of Cyclin D1, MCL-1 and MYCN

Neuroblastoma is the most common diagnosed tumor in infants and the second most common extracranial tumor of childhood. The survival rate of patients with high-risk neuroblastoma is still very low despite intensive multimodal treatments. Therefore, new treatment strategies are needed. In recent years, miRNA-based anticancer therapy has received growing attention. Advances in this novel treatment strategy strongly depends on the identification of candidate miRNAs with broad-spectrum antitumor activity. Here, we identify miR-193b as a miRNA with tumor suppressive properties. We show that miR-193b is expressed at low levels in neuroblastoma cell lines and primary tumor samples. Introduction of miR-193b mimics into nine neuroblastoma cell lines with distinct genetic characteristics significantly reduces cell growth in vitro independent of risk factors such as p53 functionality or MYCN amplification. Functionally, miR-193b induces a G1 cell cycle arrest and cell death in neuroblastoma cell lines by reducing the expression of MYCN, Cyclin D1 and MCL-1, three important oncogenes in neuroblastoma of which inhibition has shown promising results in preclinical testing. Therefore, we suggest that miR-193b may represent a new candidate for miRNA-based anticancer therapy in neuroblastoma.