Downregulation of PIF1, a potential new target of MYCN, induces apoptosis and inhibits cell migration in neuroblastoma cells.

Neuroblastoma (NB) is one of the most common malignant tumors in children. Chemotherapy resistance is one of the significant challenges in the treatment of high-risk NB patients, and it is necessary to search for new valid targets for NB treatment. This study aims to explore the possible role of PIF1 in NB by using bioinformatic analysis and downregulation of PIF1 with specific siRNA. Kyoto genome encyclopedia and R language based gene ontology was used to analyze the differentially expressed genes (DEGs) (including PIF1) when MYCN expression was silenced in NB cells. Analysis based on the R2 database showed a lower expression of PIF1 correlated with good prognosis in NB patients. Downregulation of MYCN expression by transfecting MYCN siRNA (#1, #2) into NB cells decreased the PIF1 expression at both mRNA and protein levels, while upregulation of MYCN expression by transfecting MYCN overexpressed plasmid increased the PIF1 expression. We further found that downregulation of PIF1 expression by transfecting PIF1 siRNA (#1, #2) into NB cells, increased the number of apoptotic cells, inhibited the cell survival, decreased the ability of cell migration and induced a cell cycle arrest at G1 phase. These data indicated that PIF1, as a potential new target of MYCN, maybe a novel target for NB treatment.