Evaluation of DNA mismatch repair system in cervical dysplasias and invasive carcinomas related to HPV infection.

UNLABELLED

The aim of this study was to answer the question whether the products of hMSH2 and hMLH1 genes take part in the mutation track of cervical carcinoma.

METHODS

IgG1 monoclonal antibodies (Pharmingen) detecting epitopes characteristic of hMLH1 and hMSH2 were used in the present study. The value of the half-quantitative H-score coefficient was calculated. Its threshold value was 0.4. Identification of 16 and 18 HPV types was performed by PCR.

RESULTS

An intensified hMLH1 protein expression was observed both in the squamous epithelial carcinomas and cervical adenocarcinomas (H-score of 1.44 and 0.98, respectively) as compared to the control (H-score of 0.9). However, a decreased expression of hMSH2 protein was observed in the analysed cases of carcinoma (0.9 and 0.7) as compared to the control group (1.2). An intensified expression in G3 for hMLH1 and higher hMLH1 in comparison to hMSH2 was observed.

CONCLUSIONS

1. A considerable expression of hMLH1 and hMLH1 proteins was observed in the tissues with invasive cervical carcinoma not only within epithelial but also in stromal cells. 2. More intense expression of hMLH1 and hMSH2 was observed in invasive carcinomas and CIN than in the non-neoplastic cervical tissue lesions (erosion). 3. A stronger expression was observed for the hMLH1 than for the hMSH2 proteins--contrary to the cases of carcinomas of the uterine corpus and endometrial carcinoma.