Gene expression profiles of luteal phase fallopian tube epithelium from BRCA mutation carriers resemble high-grade serous carcinoma

Purpose: To identify molecular alterations potentially involved in predisposition to adnexal serous carcinoma (SerCa) in the nonmalignant fallopian tube epithelium (FTE) of BRCA1/2 mutation carriers, given recent evidence implicating the distal FTE as a common source for SerCa. Experimental Design: We obtained and compared gene expression profiles of laser capture microdissected nonmalignant distal FTE from 12 known BRCA1/2 mutation carriers (FTEb) and 12 control women (FTEn) during the luteal and follicular phase, as well as 13 high-grade tubal and ovarian SerCa. Results: Gene expression profiles of tubal and ovarian SerCa specimens were indistinguishable by unsupervised cluster analysis and significance analysis of microarrays. FTEb samples as a group, and four individual FTEb samples from the luteal phase in particular, clustered closely with SerCa rather than normal control FTE. Differentially expressed genes from these four samples relative to other FTEb samples, as well as differentially expressed genes in all FTEb luteal samples relative to follicular samples, were mapped to the 12D protein-protein interaction database, revealing a complex network affecting signaling pathways previously implicated in tumorigenesis. Two candidates, disabled homolog 2 mitogen-responsive phosphoprotein (DAB2) and Ski-like (SKIL), were further validated by real-time reverse transcription - PCR and tissue arrays. FTEb luteal and SerCa samples expressed higher levels of oncogenic SKIL and decreased levels of tumor suppressor DAB2, relative to FTEb follicular samples. Conclusions: These findings support a common molecular pathway for adnexal SerCa and implicate factors associated with the luteal phase in predisposition to ovarian cancer in BRCA mutation carriers.