Expression of CD44v6 and RCAS1 in Uterine Cervical Carcinoma Infected with Human Papillomavirus and Its Effect on Cell Proliferation and Differentiation

OBJECTIVE: To investigate the expression of CD44v6 and RCAS1 and the presence of HPV in cervical cancer tissues, to determine serum RCAS1 levels, and to evaluate these components in correlation with clinicopathologic features and survival. METHODS: A total of 52 patients consisting of 28 squamous cell carcinoma (SCC) and 24 adenocarcinoma cases, were studied. RCAS1 and CD44v6 expression was evaluated using immunohistochemical staining. HPV 16 and 18 E6 genes were detected using PCR, and serum RCAS1 concentrations were measured using ELISA. Associations between these factors and clinicopathologic features and survival were analyzed. RESULTS: CD44v6 expression was significantly higher in SCC compared with that in adenocarcinoma (P<0.001). It also showed a significant relation to histologic grade (P<0.001) and tumor size (P=0.03). RCAS1 expression was higher in adenocarcinoma than in SCC (P=0.001), and it showed a borderline relation with histological grade (P=0.057). Overall survival was not significantly different in both CD44v6 and RCAS1 expression; however, FIGO stage (P=0.025) and tumor size (P=0.042) resulted statistically different. The pre-surgical treatment serum RCAS1 levels were not associated with any clinicopathological variables. The presence of HPV 16 E6 was higher in SCC, while the presence of HPV 18 E6 was higher in adenocarcinoma (P<0.001). Detection of HPV 16 E6 was significantly associated with expression of CD44v6. The presence of HPV both HPV 16 E6 and HPV 18 E6 was found in cancer tissues with RCAS1 expression, but without any statistical significance. CONCLUSION: CD44v6 and RCAS1 expression seems to be involved in tumor proliferation and differentiation, but it is not implicated in the progression and invasion of cervical cancer infected by HPV. Pre-treatment levels of serum RCAS1 in cervical cancer are not a diagnostic and predictive biomarker.