Immunohistochemical analysis of bcl-2, bax, mcl-1, and bcl-X expression in ovarian surface epithelial tumors

• Published in: International journal of gynecological pathology Vol. 17; no. 3; p. 255
• Main Authors: Wehrli, B M, Krajewski, S, Gascoyne, R D, Reed, J C, Gilks, C B
• Format: Journal Article
• Language: English
• Published: United States 01-07-1998
• Subjects: Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Female; Humans; Immunohistochemistry; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins - analysis; Neoplasms, Glandular and Epithelial - chemistry; Neoplasms, Glandular and Epithelial - pathology; Ovarian Neoplasms - chemistry; Ovarian Neoplasms - pathology; Proto-Oncogene Proteins - analysis; Proto-Oncogene Proteins c-bcl-2 - analysis
• ISSN: 0277-1691
• DOI: 10.1097/00004347-199807000-00010

Cell survival may be enhanced in tumors by the inhibition of apoptosis, which allows tumor promotors to exert their effects. The bcl-2 related genes have been shown to contribute to either the inhibition or induction of apoptosis in a variety of neoplasms; therefore, it was hypothesized that the expression of these genes might contribute to malignant transformation in ovarian surface epithelial tumors. The expression of bcl-2 family proteins was investigated in 28 ovarian surface epithelial tumors, including serous and mucinous benign, borderline, and malignant tumors by immunohistochemical staining with antibodies to bcl-2, bax, bcl-X, and mcl-1 proteins. Staining intensity was scored on a 1+ to 3+ scale and the benign, borderline, and malignant tumors were compared. Significantly less immunoreactive bcl-2 and bcl-X proteins were present in malignant serous tumors compared to their benign counterparts. No difference was seen in immunostaining for bax or mcl-1 when benign, borderline, or malignant serous tumors were compared. In the mucinous tumors, no differences were seen in immunostaining for any of the bcl-2 family proteins between tumor types. The loss of expression of the antiapoptotic proto-oncogenes bcl-2 or bcl-X in serous carcinomas compared to benign serous tumors, together with previous demonstrations that the presence of bcl-2 in ovarian surface epithelial cancers is a favorable prognostic indicator, suggests that bcl-2 and bcl-X have biological functions in the ovary other than inducing apoptosis, acting instead as tumor suppressor proteins.