Decreased RNA-binding protein IGF2BP2 downregulates NT5DC2, which suppresses cell proliferation, and induces cell cycle arrest and apoptosis in diffuse large B-cell lymphoma cells by regulating the p53 signaling pathway

Diffuse large B-cell lymphoma (DLBCL) remains difficult to treat clinically due to its highly aggressive characteristics. Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) and 5′-nucleotidase domain-containing 2 (NT5DC2) have been suggested as potential regulators in numerous types of cancer. The present study aimed to determine whether downregulation of IGF2BP2 and NT5DC2 suppresses cell proliferation, and induces cell cycle arrest and apoptosis in DLBCL cells by regulating the p53 signaling pathway. The expression levels of IGF2BP2 and NT5DC2 in DLBCL cells were determined by reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis. Transfection of cells with IGF2BP2 overexpressing plasmids and NT5DC2 interference plasmids was performed, and the efficacy of transfection was confirmed by RT-qPCR and western blot analysis. The viability, proliferation, cell cycle progression and apoptosis of DLBCL cells were analyzed by Cell Counting Kit-8 assay, 5-bromo-2-deoxyuridine staining and flow cytometry. RNA pull-down and immunoprecipitation assays were used to verify the binding of IGF2BP2 and NT5DC2. The expression levels of apoptosis, cell cycle and p53 pathway-associated proteins were determined by western blotting. The results revealed that NT5DC2 expression was increased in DLBCL cell lines and was the highest in OCI-Ly7 cells. IGF2BP2 expression was also increased in OCI-Ly7 cells and IGF2BP2 bound to NT5DC2. Knockdown of NT5DC2 suppressed cell viability and proliferation, induced cell cycle arrest and promoted apoptosis in DLBCL cells, which was reversed by upregulation of IGF2BP2. In addition, knockdown of NT5DC2 increased the expression of p53 and p21, but suppressed the expression of proliferating cell nuclear antigen, CDK4 and cyclin D1; these effects were reversed by upregulation of IGF2BP2. In conclusion, knockdown of NT5DC2 suppressed cell viability and proliferation, induced cell cycle arrest and promoted apoptosis in DLBCL cells by regulating the p53 signaling pathway and these effects were reversed by upregulation of IGF2BP2.