Immunohistochemical study of ras oncogene expression in endometrial and cervical human lesions

The Y13 259 monoclonal antibody to the ras p21 protein was used in an immunohistochemical assay to study the levels of ras p21 in human uterine lesions as compared to normal tissue. Out of 73 hysterectomies obtained we have examined ras p21 expression in separately made sections from the endometrium, the cervix and leiomyomas found in the same specimens. A total of 155 tissue sections were finally evaluated and included: 55 endometrial mucosae (normal, hyperplastic and atrophic), 13 leiomyomas, 60 cervicitis (mild, moderate and severe with or without dysplasia), 3 in situ and 7 invasive carcinoma of the cervix, 12 invasive adenocarcinoma of the endometrium and 5 endometrial adenocarcinomas, which involved the cervical canal. Out of the 73 hysterectomy specimens 27 lesions were malignant and showed elevated expression of ras p21. The remaining 128 were normal or atrophic mucosae and benign or premalignant lesions, which were mostly negative. However, all cases of severe cervicitis and dysplasias and 6 out of the 12 hyperplastic endometrial lesions were found to be moderately or highly positive. Our results suggest that elevated expression of ras oncogenes may play an important role in the development of human uterine lesions.