Abstract:
Objective To assess biological functions and underlying mechanisms of midkine (MK) in cell growth and differentiation of neuroblastoma TNB1 cells.
Methods First, the correlation between MK expression and survival rate was assessed in patients with neuroblastoma whose data were obtained from a clinical database. Furthermore, cell growth and differentiation ability of TNB1 cells were evaluated after treatment with MK shRNA-containing lentivirus in vitro. Second, the related gene of MK was screened out by analyzing data from the clinical database, and its expression in MK shRNA-treated TNB1 cells was assessed using real-time PCR. Finally, TNB1 cells were infected with MK shRNA- and downregulated in renal carcinoma 1 (DRR1) shRNA-containing lentivirus, and the effect of MK-DRR1 axis on cell differentiation and soft agar colony formation was evaluated.
Results Data from the clinical database revealed the negative correlation between MK expression and survival rate of patients with neuroblastoma (P<0.01). Downregulation of MK repressed cell growth and promoted TNB1 cell differentiation. Analysis of the clinical database revealed a negative correlation between MK expression and DRR1 expression (P<0.01). Real-time PCR results confirmed that DRR1 expression was increased in MK shRNA-treated TNB1 cells (P<0.01). Combined treatment with MK shRNA and DRR1 shRNA rescued the effect of MK shRNA on cell differentiation and soft agar colony formation(P<0.01).
Conclusions MK mediated the growth and differentiation of TNB1 cells by regulating DRR1 expression.