N-myc downstream regulated gene-1/Cap43 may play an important role in malignant progression of prostate cancer, in its close association with E-cadherin

N-myc downstream regulated gene-1 (NDRG1)/Cap43 plays an important role in tumor progression and metastases in many kinds of cancers. Recently, it was reported that NDRG1/Cap43 is involved in the aggressiveness of prostate cancer and also that its expression is associated with the expression of E-cadherin in prostate carcinoma cell lines. In the current study, to elucidate the functional and pathologic roles of NDRG1/Cap43 in prostate cancer, we investigated whether the expression of NDRG1/Cap43 is associated with the clinicopathologic parameters of prostate cancer or E-cadherin expression. NDRG1/Cap43 expression and E-cadherin expression were examined immunohistochemically in 148 patients with prostate cancer. We investigated the correlation between membranous or cytoplasmic expression of NDRG1/Cap43 and E-cadherin and evaluated the prognostic or clinicopathologic significance of the expression of NDRG1/Cap43. The patients with decreased NDRG1/Cap43 membranous expression showed significantly lower disease-free survival rates compared with the patients with preserved NDRG1/Cap43 membranous expression. Decreased membranous and high cytoplasmic NDRG1/Cap43 expression was also correlated with a higher Gleason score. A significant correlation was observed between NDRG1/Cap43 membranous expression and E-cadherin membranous expression (r = 0.7130; P < .0001) and between NDRG1/Cap43 cytoplasmic expression and E-cadherin cytoplasmic expression (r = 0.5847; P < .0001). Decreased NDRG1/Cap43 membranous expression had a significant impact on patient disease-free survival in multivariate analysis (P = .0175). NDRG1/Cap43 could be a novel marker for malignant progression and poor prognosis in prostate cancer, plausibly in its close association with the down-regulation of E-cadherin expression.