Expression of Nucleophosmin/NPM1 correlates with migration and invasiveness of colon cancer cells

BACKGROUND: We aimed to examine the expression level of Nucleophosmin (NPM1) protein in colon cancer tissues and to investigate the potential role of NPM1 in the regulation of cell migration and invasiveness. METHODS: Immunohistochemical assay was performed to examine the expression pattern of NPM1 in 31 groups of colonic carcinoma samples, including colon tumors, adjacent normal tissues, and matched metastatic lymph nodes from the same patients. Small interfering RNA technique and exogenous expression of wild type NPM1 methods were used to further verify the function of NPM1. RESULTS: High-expression of NPM1 correlates with lymph node metastasis (P = 0.0003) and poor survival rate of human colon cancer patients (P = 0.017). SiRNA-mediated reduction of NPM1 was also shown to inhibit the migration and invasiveness of metastatic colon cancer HCT116 cell line. In addition, the exogenous expression of NPM1 in HT29 cells, a NPM1 low expression and low invasive colon cancer cell line, enhanced cell migration and invasiveness along with increased cell proliferation. CONCLUSIONS: The current study uncovered the critical role of NPM1 in the regulation of colon cancer cells migration and invasion, and NPM1 may serve as a potential marker for the prognosis of colon cancer patients.