In situ distribution of transforming growth factor alpha in normal human tissues and in malignant tumours of the ovary.

The distribution of transforming growth factor alpha (TGF-alpha) in human normal tissues from the uterus, Fallopian tube, ovary, small and large intestine, lung, spleen, kidney, and skin was studied by immunohistochemistry. TGF-alpha was found in epidermis, bronchial epithelium, intestinal mucosa, renal tubules, endo- as well as in exocervical and endometrial epithelium, and in the serous epithelium of the Fallopian tube. No TGF-alpha was detected in the stromal components of any of the tissues nor in any of the pre- and post-menopausal ovaries studied. Twenty-nine ovarian tumours including 23 ovarian carcinomas, one malignant mixed Mullerian tumour, two ovarian metastases of gastrointestinal carcinomas, one dysgerminoma, one sarcoma, and one fibroma were studied for TGF-alpha by the same immunohistochemical method. In 25 cases, specific cytoplasmic staining for TGF-alpha of epithelial tumour cells could be demonstrated. The pattern and intensity of the TGF-alpha immunostain varied among the TGF-alpha-positive tumours. No TGF-alpha was found by immunohistochemistry in the remaining four cases nor in the stromal tumour components of any of the lesions studied. Northern blot analysis for TGF-alpha mRNA was performed on 12 of the tumours. While the immunohistochemistry and blotting results correlated well in ten cases, discordant results were obtained in two lesions.