CA125 expression in spontaneous ovarian adenocarcinomas from laying hens.

OBJECTIVE Currently, there is not a fully characterized model for human ovarian cancer; however, 2- to 4-year-old laying hens spontaneously develop ovarian tumors. CA125 expression is a hallmark of ovarian cancer in women. The major objective of this study was to characterize the in vitro growth of avian ovarian tumor cells, and CA125 expression in avian ovarian tumors. METHODS Immunohistochemistry was employed to evaluate CA125 expression in avian ovarian tumor tissue. A high temperature antigen retrieval step was an essential part of the CA125 staining procedure. In vitro growth curves were constructed for avian ovarian cancer cells. Western blotting was used to estimate the size of the CA125 reactive protein and to confirm CA125 expression. RESULTS The growth of avian tumors in culture fits a sigmoidal curve for cell growth and suggests a cell cycle time of 28 h. The tumors taken from the chicken stained positive for CA125. Approximately 90% of cells isolated from avian ovarian tumors also stained positive for CA125. Western blots show a band of approximately 25 kDa when immunodetected with CA125. CONCLUSIONS Similar to human ovarian tumors, chicken ovarian tumors express CA125. Cultured chicken ovarian cancer cells express CA125 and CA125 expression does not appear to change with time in culture.