Expression of fos and jun proto-oncogenes in benign versus malignant humanuterine tissue

Objective. The objective of this study was to evaluate expression of fos an d jun proto-oncogenes in benign human uterine tissue compared with malignan t uterine tissue. Methods. Forty-two endometrial tissue specimens were obtained at the time o f hysterectomy. Tissue samples from different phases of the menstrual cycle and from postmenopausal patients were stained using immunohistochemical me thods to detect Fos and Jun proteins, estrogen and progesterone receptor st atus, and Ki67 (detects a nuclear antigen associated with proliferating cel ls). Tissue was examined microscopically for nuclear staining in endometria l epithelium and stroma. The endometrium was based on the patient's last me nstrual period, pathologic dating, and proliferative versus nonproliferativ e status as determined by Ki67. Benign and malignant specimens were subject ed to Northern blot analysis to evaluate levels of expression of c-fos, c-j un, and jun-B mRNA. The pattern of c-fos mRNA expression in malignant sampl es was further evaluated using in situ hybridization. Results. In proliferative, secretory, postmenopausal, and progesterone-infl uenced, uterine specimens immunohistochemically stained and examined, the e ndometrial and stromal nuclei stained for both Fos and Jun in varying inten sities. However, no pattern was found in the variation of intensity accordi ng to the phase of the endometrium. Similarly, in malignant and benign endo metrial tissue examined by Northern blot and in situ hybridization analyses , expression of proto-oncogene mRNAs was readily detectable, but no statist ical correlation between type of tissue examined, grade of adenocarcinoma, and stage of endometrial cancer was found in this study. Conclusions. In rodent models, control of uterine cell proliferation is rel ated to change in expression of fos and jun protooncogenes. Our results ind icate that hormonal control is likely to be different in human endometrium and probably involves genes other than the proto-oncogenes under study. Exp ression of Fos and Jun do not correlate with endometrial cancer stage and g rade. (C) 2000 Academic Press.