Prostatic carcinoma is a common public health problem in aging people. Cyclin D1 proto-oncogene is an important regulator of G1 to S phase progression in many different cell types. It is believed to play an important role in both tumorigenesis and grading of many cancers including prostatic carcinoma; high levels of these proteins have been reported in certain human malignancies and have been implicated in aberrant cell division and dysregulated tumor growth. The aims of this study was to examine the immunohistochemical expression of Cyclin D1 in prostatic carcinoma and to demonstrate the association or relation between Cyclin D1 expressions and to determine the aggressiveness of the malignant tumors by Gleason Score. In this study, 50 samples, 25 cases of prostatic cancer and 25 cases of benign prostatic tissues, were studied for Cyclin D1 expression using an immunohistochemical technique which was performed on routinely processed, formalin-fixed, and paraffin-embedded tissues; the tissues were then sectioned into thickness of (3–5 µm) with rotary microtome instrument, and immunohistochemical expression of Cyclin D1 was evaluated in all cases. All of the primary human prostatic cancer samples revealed in different ranges of intensity from weak (+1), moderate (+2) to strongly positive nuclear staining (+3) for Cyclin D1. In this study, we revealed no nuclear staining in the benign prostatic hyperplasia (PBH) disease (+0) in 21 cases (84%), and 4 cases (16%) were ranged in different color intensity; 3 (12%) were weak (1+) and 1 (4%) was moderate (2+), while prostatic cancer cases were also evaluated in different colour intensity; 13 cases (52%) were (+3), 7 (28%) were (+2), 3 were (12%) were (+1), and only two (8%) were negative. There was no significance correlation between Gleason's score and the intensity of Cyclin D1 expression. Conclusively, it can be said that Cyclin D1 may be helpful in the differentiation between BPH and prostate cancer, the correlation between the intensity of Cyclin D1 expression and prostatic diseases was statistically highly significant (p-value = 0.00). The authors recommend to use Cyclin D1 as a tumor marker to prostatic carcinoma.
Keywords: prostatic carcinoma, Cyclin D1, immunohistochemistry