Msh2, Mlh1, Fhit, p53, Bcl-2, and Bax expression in invasive and in situ squamous cell carcinoma of the uterine cervix.

To analyze relevant factors and their effects on neoplastic progression in cervical carcinoma, a panel of genetic markers was studied. Paraffin-embedded tissue sections were obtained from 37 patients with carcinoma of the uterine cervix, 14 noninvasive squamous cell carcinomas (NISCCs), and 23 invasive squamous cell carcinomas (ISCCs). Immunoreactivity of Msh2, Mlh1, Fhit, p53, Bcl-2, and Bax proteins was examined by immunohistochemical staining with appropriate antibodies. Positive staining of Msh2 was detected in 13 of 14 (92.9%) NISCCs and in 13 of 23 (56.5%) ISCCs (P < 0.02). Mlh1 immunoreactivity was observed in 10 of 14 (71.4%) NISCCs and in 8 of 23 (34.8%) ISCCs (P < 0.04). Overexpression of p53 protein was found in 4 of 14 (28.6%) NISCCs and in 16 of 23 (69.6%) ISCCs (P < 0.02). Bcl-2 overexpression was detected in 2 of 14 (14.3%) NISCCs and in 15 of 23 (65.2%) ISCCs (P < 0.003). No significant difference in the two types of lesion was found for Bax and Fhit expression. The relationship between Mlh1, Msh2, and p53 protein expression was significant (P < 0.001 and P < 0.001, respectively), as was that between Fhit and Bax immunoreactivity (P < 0.02). In conclusion, we consider that altered expression of Msh2, Mlh1, p53, and Bcl-2 may be a critical event during cervical cancer progression, whereas Fhit may be a component of a proapoptotic pathway.