Objective: beta-Catenin has been previously associated with oncogenic activity in human cancers. We evaluated whether beta-catenin also plays a role in papillary serous ovarian neoplasms.
Methods: Immunohistochemistry for beta-catenin was performed on the primary ovarian serous neoplasms of 105 women. Of these, 10 were low malignant potential (LMP) serous tumors, and 95 were serous cancers. Nuclear beta-catenin staining was correlated with grade of tumor and median survival. OVCAR-3, OVCA-420, OVCA-432, and MDAH-277-10c were evaluated for beta-catenin localization and transfected with a T-cell factor (TCF) responsive reporter to evaluate beta-catenin transcriptional activity.
Results: Of 105 serous tumors, 13 (12.3%) demonstrated beta-catenin nuclear staining. Eleven of 48 high-grade serous carcinomas (23.0%) demonstrated nuclear staining compared with 1 low-grade serous carcinoma (2.1%) (P = 0.006). One LMP tumor had nuclear staining. beta-Catenin nuclear localization was undetectable in the cell lines tested. Furthermore, transient transfection of the cell lines with a TCF-responsive reporter did not demonstrate significant constitutive transcriptional activation.
Conclusions: We found a statistically significant correlation between beta-catenin nuclear localization and ovarian high-grade serous carcinomas. Thus, deregulation of beta-catenin may play a role in the pathogenesis of ovarian high-grade serous carcinomas in contrast to ovarian low-grade serous carcinomas and LMP serous tumors.