[Relationship between expressions of telomerase genes and apoptosis related genes in mammary ductal atypical hyperplasia].

BACKGROUND & OBJECTIVE: Recent studies showed that the activating of telomerase and excessive expression of apoptosis suppressor genes were related to the development of many tumors. This study was designed to investigate the expression of telomerase genes (hTR, hTRT) and apoptosis related genes (p53, bcl-2) in mammary atypical ductal hyperplasia for exploring the change of telomerase activity and apoptosis related genes in the process of mammary ductal dysplasia to malignant transformation.

METHOD

Expressions of telomerase genes (hTR, hTRT) and apoptosis related genes (p53, bcl-2) were detected by in situ hybridization and expression of the mutant p53 protein was detected by immunohistochemistry were detected in 44 patients with mammary atypical ductal hyperplasia, those expression were compared with those of the 6 benign hyperplasia and 26 breast carcinoma.

RESULT

High expressions of telomerase genes (hTR, hTRT mRNA) in severe atypical ductal hyperplasia (60.9%, 52.1%) is of significantly difference from that in mild-medium atypical ductal hyperplasia (22.2%, 11.1%; 33.3%, 25.0%) and breast cancer (88.5%, 80.8%). The upgrading of atypia link with decreased expression of wild p53 mRNA (mild: 55.6%; medium: 41.7%; severe: 26.1%) and increased expression of the mutant p53 protein (mild: 11.1%; medium: 25.0%; severe: 34.8%). As for bcl-2 mRNA, it shows moderate expression, especially in severe atypical ductal hyperplasia.

CONCLUSION

Our study revealed significant correlation between expressions of telomerase genes (hTR, hTRT) and the state of malignant transformation in mammary atypical ductal hyperplasia. Decreased expression of wild p53 gene, increased expression of mutant p53 protein, and overexpression of bcl-2 gene were associated with telomerase.