Immunoexpression of p53 and hMSH2 in oral squamous cell carcinoma and oral dysplastic lesions in Yemen: relationship to oral risk habits and prognostic factors.

Although several studies analyzed p53 and mismatch repair (MMR) gene expression separately in oral squamous cell carcinoma (SCC), no reports of combined assessment of both proteins in this cancer. The aim of this study was to investigate the roles of p53 and hMSH2 proteins in oral SCC as well as in oral dysplastic lesions (DL) in Yemen. Immunohistochemistry was used to examine the pattern of expression of p53 and hmsh2 proteins in 70 oral SCC and 21 oral DL obtained from Yemeni patients. p53 Immunoexpression was detected in 24 of the 70 oral SCC (34.3%) and 3 of 21 DL (14.3%) with no significant difference between the two groups. On the other hand, reduced expression of hMSH2 was detected in 26 of the 70 oral SCC (37.1%) and 2 of 21 oral DL (9.5%) with a statistically significant difference (P=0.03). Both proteins were significantly related to the grade of tumor differentiation (P=0.007 and 0.02, respectively). There was an inverse correlation between the levels of p53 and hMSH2 immunoexpression in the oral SCC (r=0.42, P=0.01). This study suggested that p53 may play a role in the early stages of oral carcinogenesis, while hMSH2 may be altered in the late stages. More importantly, the roles of p53 and hMSH2 in oral carcinogenesis seem to be interrelated in the pathogenetic pathway of oral SCC. Such a relationship has not been published previously in this type of cancer and needs to be clarified in future studies.

Human papilloma virus and p53 expression in bladder cancer in Egypt: relationship to schistosomiasis and clinicopathologic factors.

The aim of the current study was to compare the role of p53 and human papillomavirus (HPV) in schistosomiasis-related and schistosomiasis-unrelated carcinoma of the urinary bladder. To achieve this aim, we investigated 114 bladder carcinomas for p53 oncoprotein expression by immunohistochemistry and for human papillomavirus by in situ hybridization technique. The results revealed that 64 tumors (56.1%) were schistosomiasis-associated. Sixty seven (58.8%) were transitional cell carcinomas and 32 (28%) were squamous cell carcinomas. The remaining 15 tumors (13.2%) included adenocarcinomas and sarcomatoid carcinomas. In both schistosomiasis-associated and non-associated carcinomas, p53 oncoprotein expression was significantly higher in poorly differentiated tumors. However, it was significantly higher in locally more invasive tumors in the schistosomal carcinomas only. HPV types 16/18 could be detected in 1 of the 114 bladder carcinomas (0.95%), which was schistosomiasis-related squamous cell carcinoma in situ. These results suggest that p53 immunohistochemistry can be a prognostic factor in both schistosomal and nonschistosomal bladder cancer. More importantly, HPV does not seem to play a role in the pathogenesis of either type of bladder cancer in our country.