Association of ring box-1 protein overexpression with clinicopathologic prognostic parameters in prostate carcinoma

To determine the expression of Ring Box-1 (RBX-1) protein in prostate carcinoma (PCa) and the association between RBX-1 expression and clinicopathologic prognostic parameters.

Relevant data such as age, preoperative serum PSA values, and tumor stage were obtained from 51 patients' with PCa record who underwent radical prostatectomy between January 2010 and March 2014. Hematoxylin-eosin stained pathology slides were evaluated by 2 pathologists blinded to patients' data in order to determine Gleason grade groups, tumor stage, tumor volume, capsule invasion, lymphovascular invasion, perineural invasion, and seminal vesicle invasion. Immunoreactivity scoring system (IRS) was used to determine RBX-1 expressions.

A statistically significant difference was determined in terms of RBX-1 expression between non tumoral prostate tissue, high grade prostatic intraepithelial neoplasia (H-PIN) and carcinoma foci (P = 0.001). RBX-1 expression in the Gleason pattern 4 was higher than the Gleason pattern 3 and H-PIN foci as well as non tumoral prostate tissue. Likewise, in cases with PSA levels of>10.1ng/ml, RBX-1 expression was higher than those≤10ng/ml. Moreover, RBX-1 expression of stage II cases was higher than stage I (P = 0.019), RBX-1 expression of stage III higher than stage I cases (P = 0.044). However, RBX-1 expression was not related with clinicopathologic parameters including patient age, tumor volume, lymphovascular invasion, perineural invasion, seminal vesicle invasion, or capsule invasion.

RBX-1 protein is overexpressed in PCa and associated with clinicopathologic prognostic parameters related with biological potential of the aggressive disease. Further studies of basic and molecular science are needed to reveal clinical and therapeutic implications of RBX-1 in PCa.