Objective: The reactivity of gynecologic cancer proteins with monoclonal antibody (MAb) directed
against the human immunodeficiency virus I (HIV-I) was tested.Methods: Cytoplasmic and nuclear proteins, extracted from a broad range of gynecologic cancers
obtained during standard surgical procedures, were tested in Western blotting with MAb 5023
developed against the amino acid sequences 308–322 of the envelope protein gp120 of HIV-I.Results: Three cell membrane proteins, Mrl20,000 (p120), Mr41,000 (p41), and Mr24,000 (p24), and
one chromatin protein, Mr24,000 (p24), were detected by MAb 5023 in invasive, poorly differentiated
cervical squamous-cell carcinoma; ovarian serous cystadenocarcinoma; poorly and well-differentiated
endometrial carcinoma; vulvar squamous-cell carcinoma; and malignant mixed müllerian tumor. The
same antigens were identified in cervical carcinoma cell line SiHa. Neither p120 nor p24 was recognized
by other MAbs directed against the variable loop of gp120. Antigens p120 and p41 were undetectable in
normal ovarian tissue and in biopsy samples of normal vaginal and rectal mucosa. Rectosigmoid cancer
as well as colon carcinoma, lung carcinoma, and melanoma cell lines all tested negative.Conclusions: The identified antigens may represent either the products of human genes (proto-onc-ogenes)
or, more likely, the products of an unknown virus specifically expressed in female cancer.
