[Apoptosis and uterine cervical carcinogenesis].

OBJECTIVE

To investigate the possible role of apoptosis in the development of uterine cervical carcinoma.

METHODS

Formalin-fixed, paraffin-embedded samples from 190 patients [41 patients with severe dysplasia (SD); 37 with carcinoma in situ(CIS); 31 with microinvasive carcinoma (MIC), 40 with fran invasive large cell non-keratinizing epidermoid carcinoma (IC)], and 41 samples from normal cervical squamous epithelium (NE) were studied. The number of apoptotic cells was assessed in situ by the TDT-mediated dUTP-biotin nick end labeling (TUNEL) method. PCNA, p53 and bcl-2 were demonstrated immunohistochemically.

RESULTS

(1) In NE, TUNEL-positive cells were found in the superficial layer and PCNA-positive cells were confined in the lamina profunda, while in cervical neoplasia these cells were irregulasly scattered throughout the cervical lesions. (2) The TUNEL staining index decreased while PCNA increased with progression of the neoplasm, showing a significant negative correlation between apoptosis and proliferation. (3) In patients with SD and CIS who had overexpression of p53 and bcl-2 proteins, the cells positively stained by TUNEL were significantly less in number than in these with negative p53 and bcl-2 expression. No such observation for PCNA expression.

CONCLUSION

These results suggest that apoptosis is associated with the early process of cervical carcinogenesis and apoptosis is closely correlated with overexpression of p53 and bcl-2 proteins.