High levels of nm23 expression are related to cell proliferation in human prostate cancer.

Reduced expression of the nm23 gene has been correlated with high metastatic potential in rodent mammary tumors and human breast cancer. The expression of this gene was studied in human prostate cancer tissue from 43 patients by immunohistochemistry using anti-nm23-H1 antibodies. Intense immunostaining was observed in 71.4% of the patients with clinical stage D disease as compared to 23.1% in clinical stage B and 18.7% in stage C disease (P < 0.05). Similarly intense immunostaining was present in 75% of poorly differentiated cancers versus only 28.6% in men with moderately differentiated cancer. nm23-H1 mRNA expression was measured by Northern blot analysis during phases of the cell cycle in DU 145, PC-3, LNCaP, and TSU-Prl human prostate cancer cell lines. Cells were synchronized in G0-G1 phases by serum deprivation and at the G1-S boundary by aphidicolin. nm23-H1 mRNA levels declined during serum deprivation and increased rapidly following serum addition. Although nm23-H1 was expressed continuously throughout the cell cycle, higher expression was observed in late G1, early S, and G2-M phases. These results indicate that nm23-H1 gene expression is related to the proliferative phase of cell growth.