Correlation of MCM2 detection with stage and virology of cervical cancer

The highly conserved mini-chromosome maintenance proteins (MCM) are important in the initiation of DNA replication. Few studies have correlated MCM expression with the progression of cancer. Objectives: (i) To analyze the expression of MCM2 in cervical cancer; (ii) to correlate MCM2 expression with the clinical tumor staging according to FIGO classification, and (iii) to relate HPV type to MCM2 expression. Methods: Tissue micro-arrays (TMA) from patients with invasive cervical cancer and controls were analyzed. Human papillomavirus (HPV) DNA detection and HPV types were determined by in situ hybridization, PCR, and sequencing. MCM2 expression was analyzed by immunohistochemistry. Results: The most prevalent HPV types found in invasive cancer were HPV 16 (66.6%), followed by HPV 33 (11.8%), and HPV 35 (3.6%). An increased (p<0.05) expression of MCM2 was found in invasive cervical cancers compared to controls. Moreover, a strong correlation was found between the MCM2-positive cells and the presence of HPV DNA detected by in situ hybridization. No statistically significant difference was observed between MCM2 expression and FIGO stage. Conclusions: The present study shows that HPV-infected cells strongly express MCM2; nevertheless, our data suggests that MCM2 is not a good biomarker when comparing the different clinical stages of cervical cancer.