Deep Quantitative Proteomics Identifies Conserved Proteome Alterations in Low and High-Grade Serous Ovarian Cancers
Low-grade serous ovarian carcinoma (LGSOC) is a rare and largely chemoresistant subtype of epithelial ovarian cancer. Unlike treatment for high-grade serous ovarian cancer (HGSOC), management options for LGSOC patients are limited, in part, due to a lack of deep molecular characterization of this disease. To address this limitation, we performed quantitative mass spectrometry-based proteomic analyses of whole tissue collections of tumors harvested from LGSOC (n=12) and HGSOC (n=24) patients or normal fallopian tube tissues (n=12) from women with benign disease. We quantified 7,043 proteins across all patient samples and unsupervised analyses revealed proteome alterations distinctly stratify fallopian tube tissue, LGSOC, and HGSOC tumors. Proteins elevated in LGSOC compared to HGSOC tumors (LIMMA adjusted p < 0.05) were enriched for pathways regulating cilium assembly and included a pathway regulating activation of FAK1 by MET, a therapeutic target in LGSOC. Using data from an independe