INHIBIN AND ACTIVIN ARE DEMONSTRABLE BY IMMUNOHISTOCHEMISTRY IN OVARIAN TUMOR-TISSUE

Elevated serum immunoreactive inhibin concentrations have been reporte d in patients with mucinous and granulosa cell tumors of the ovary, Th e present study aimed to determine whether the inhibins and/or the rel ated peptides, the activins, were demonstrable within ovarian tumor ti ssue. Immunohistochemical analyses were performed on 11 ovarian tumors , 5 mucinous, 3 serous, 1 granulosa, 1 clear cell, and 1 metastatic co lonic cancer, Both monoclonal and polyclonal antisera specific for inh ibin-A, activin-a, and activin-B, and their alpha-, beta(A)-, and beta (B)-subunits were used. The mucinous cells of all five mucinous tumors showed positive staining for activin-A and activin-B, and their beta( A)- and beta(B)-subunits, and three stained positive for inhibin-A and the alpha -subunit. The granulosa cell tumor also showed positive sta ining for inhibin-A and the activins. The remaining tumors were negati ve. The findings are consistent with the hypersecretion of inhibin (an d possibly activin) by some ovarian malignancies and suggest that immu nohistochemistry for the inhibins and the activins should be explored further in the classification of ovarian malignancies. (C) 1995 Academ ic Press, Inc.