FXYD5 (dysadherin) upregulation predicts shorter survival and reveals platinum resistance in high-grade serous ovarian cancer

High-grade serous ovarian carcinoma (HGSOC) is generally associated with a very dismal prognosis. Nevertheless, patients with similar clinicopathological characteristics can have markedly different clinical outcomes. Our aim was the identification of novel molecular determinants influencing survival. Gene expression profiles of 12 HGSOC long-term and 27 short-term survivors (training set) were generated by microarray, and a prognostic signature was identified and further evaluated on an independent extensive HGSOC dataset through a meta-analysis approach. Snap-frozen tumor biopsies were obtained at primary surgery from 39 HGSOC patients: 27 short-term survivors, who lived less than 3 years after initial diagnosis, and 12 long-term survivors, who lived more than 7 years. Total RNA was extracted and hybridized to Affymetrix oligonucleotide microarray chips. On the basis of their Platinum Free Interval (PFI), defined as the time between the last dose of first-line carboplatin-based chemotherapy and the date of tumor progression, HGSOC patients were defined as “resistant” (PFI<6 months), “partially sensitive” (PFI 6-12 months), and “sensitive” (PFI>12 months).