Dual use of a single Wilms' tumor 1 immunohistochemistry in evaluation of ovarian tumors: a preliminary study of 20 cases

Our previous studies revealed that a single Wilms' tumor 1 (WT-1) immunohistochemistry can be used to elucidate both the myoepithelial cells and blood vessels of human breast tumors. As the human ovary is rich in blood vessels, and WT-1 has been used as a biomarker for ovarian tumors, our current study attempted to assess if a single WT-1 immunohistochemistry has dual usages in evaluation of ovarian tumor and endothelial cells. Paraffin-embedded tissue sections were prepared from 20 cases of ovarian tumors. A set of four consecutive sections from each case were subjected to immunohistochemistry with a mouse monoclonal antibody against the human WT-1 protein, a well defined ovarian tumor marker, CA-125, and a endothelial cell phenotypic marker, CD34, respectively. From each case, 4-5 randomly selected fields were photographed, and expression of these molecules in the same structures were compared. Distinct WT-1 immunoreactivities were seen in both ovarian tumor and endothelial cells. Over 90% of WT-1 positive tumor and endothelial cells were positive for CA-125 and CD34, respectively. Similarly, over 90% of CA-125 or CD34 positive cells co-express WT-1 in tumor or endothelial cells, respectively. Our findings suggest that a single WT-1 immunohistochemistry can be used to assess both the tumor cells and micro-vascular density in ovarian tumors. Our findings also suggest that as WT-1 is expressed in both tumor and endothelial cells, the development of therapeutic agents to target WT-1 may provide an effective treatment option for ovarian cancer.