Abstract

Background: Urinary bladder cancers are mostly affecting the older people, ranking the fifth most common in the western world, where the transitional cell (urothelial) carcinoma is the most common type. Human cytomegalovirus infects and on comodulates tumor cells, thereby increases their malignancy. Cyclin dependent kinase 2 (Cdk2) phosphorylates retinoblastoma protein which is important in transition from G1 to S phase, thus the inhibition of this protein results in apoptosis of the targeted tumorous cells.
Objective: To analyse of the co-expression of Cdk2 along with HCMV infection of a group of bladder transitional cell carcinoma tissues.
Patients and methods: Seventy formalin-fixed, paraffin- embedded bladder biopsies were enrolled in this study; 30 from bladder cancers , 25 from benign tumors and 15 bladder tissues with unremarkable pathological changes (as an apparently healthy control group). Chromogenic In Situ Hybridization (CISH) was done for detecting HCMV whereas immunohistochemistry (IHC) was used to assess the expression of Cdk2.
Results: CISH reactions for HCMV were detected in 56.7 % (17 out of 30) of bladder cancer biopsies and in 24 % (6 out of 25) of biopsies from benign bladder tumors. No positive– ISH reactions were detected in the control tissues. The positive Cdk2-IHC reactions were detected in 60% (18 out of 30) of bladder cancers and in 45% (13 out of 30) of benign bladder tumors biopsies. No IHC- signals were reported in the control tissues. Statistically, highly significant differences were present between each bladder tumors groups and the control group.
Conclusions: Detection of co-expressions of Cdk2 with HCMV in bladder transitional cell carcinoma could point both for a possible roles in bladder pathogenesis and /or carcinogenesis.

Key words: Bladder transitional cell carcinoma; HCMV; Cyclin dependent kinase 2; CISH; IHC.