Discovery Metabolomics of Early-Stage Ovarian Cancer in a Dicer-Pten Double Knockout Murine Model

LAURA WINALSKI; CHRISTINA M. JONES; MARÍA EUGENIA MONGE; JAEYEON KIM; MARTIN M. MATZUK; FACUNDO M. FERNÁNDEZ

Atlanta

Conferencia; Pittcon 2016 Conference & Expo; 2016

A Dicer-Pten double-knockout (DKO) mouse model of high-grade serous ovarian cancer (HGSC) has proved to be a valuable means for understanding the molecular basis of the deadliest gynecological cancer among women, with a global 5-year survival rate of only 44.2%. Characterized by rapid growing tumors, most cases remain undiagnosed until the cancer is late-stage. Using ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry (MS), our team is studying early metabolome changes identifiable in DKO mouse serum which could aid in early detection of this highly aggressive disease. Blood serum samples were collected from control and early-stage DKO mice. Metabolites were extracted after protein precipitation using methanol in a 3:1 (v/v) dilution ratio to serum. Metabolite extracts were then lyophilized and reconstituted in the initial composition of the chromatographic mobile phase. High resolution mass spectra were acquired in positive electrospray ionization mode for the m/z 50-1200 range. Analysis was conducted using a Waters ACCQUITY H Class system coupled to a Xevo G2 QTOF mass spectrometer. Metabolic features were extracted using MZmine 2.10 software. With 17 metabolites selected from these profiles using genetic algorithms for variable selection, orthogonal projection to latent structures-discriminant analysis (oPLS-DA) separated early-stage DKO mice from control mice with 98% accuracy and sensitivity, and 100% specificity. Continuing work involves identifying these 17 discriminating features utilizing UPLC tandem MS, retention time, and ion mobility collisional cross section matching to chemical standards for further validation, thereby providing insight into the metabolic alterations associated with the developments and proliferation of HGSC.