Expression and significance of Id1 in prostate cancer

Objective:It has been proved recently that Id1 (inhibitor of differentiation or inhibitor of DNA binding)is related to tumorigenesis, invasion and metastasis in some cancers. This study was to explore the expression of Id1 protein in human prostate cancer, and to analysze its potential clinical signifi cance. Methods: By SP immunohistochemistry, the expression of Id1 protein were detected in paraffin-embeded specimens of 43 prostate cancer(PC) cases, 12 benign prostatic hyperplasia (BPH) cases and 2 normal prostate. Results:There were no Id1 expression in normal prostate tissue, and negative to weak expression of Id1 in BPH(5/12). In contrast, all of prostate cancer (43/43) tissues showed moderate to high positive Id1 expression, which was significantly higher than that of BPH (P0.01) . Furthermore, Id1 overexpression was correlated with the increasing of Gleason grade (P0.01). Conclusion: In prostate cancer, Id1 protein is overexpressed and the level of Id1 expressed is positive correlated with Gleason grade, suggesting that Id1 is associated with prostate tumor malignancy. Id1 might be used as a new marker of PC for diagnosis and therapy.