MIR152, MIR200B, and MIR338, human positional and functional neuroblastoma candidates, are involved in neuroblast differentiation and apoptosis

MicroRNAs (MIRs) perform critical regulatory functions within cell networks, both in physiology as well as in pathology. Through the positional gene candidate approach, we have identified three MIRs (MIR152, MIR200B, and MIR338) that are located in regions frequently altered in neuroblastoma (NB) and target mRNAs encoding proteins involved in cell proliferation, neuroblast differentiation, neuroblast migration, and apoptosis. Expression analysis in NB biopsies and NB cell lines showed that these MIRs are dysregulated. We have characterized a CpG island, close to the gene encoding MIR200B and hypermethylated in NB samples, that explains its negative regulation. Expression of MIR152, MIR200B, and MIR338 is specifically modulated in NB cell lines during differentiation and apoptosis. Functional genomic experiments through enforced expression of MIR200B and knockdown of MIR152 resulted in a significant decrease of the invasion activity of SH-SY5Y cells. Reconstruction of a NB network comprising MIR152, MIR200B, and MIR338 allowed us to confirm their role in the control of NB cell stemness and apoptosis: This suggests that altered regulation of these MIRs could have a role in NB pathogenesis by interfering with the molecular mechanisms, which physiologically control differentiation and death of neuroblasts. Accordingly, they could be considered as new NB biomarkers and potential targets of antagomirs or epigenetic therapies.