Abstract GMM-016: CEREBELLIN-2 (CBLN2) IS DIFFERENTIALLY EXPRESSED IN OVARIAN CANCER SUBTYPES

Abstract

BACKGROUND: Cerebellin-2 (CBLN2) is a 24 kDa cytoplasmic, membrane and secreted glycoprotein that forms intracellular and extracellular homodimer and heterodimers. CBLN29s role in ovarian cancer pathogenesis has not been studied. EXPERIMENTAL PROCEDURES: Serum-free conditioned media from twenty-two cell lines, represented by SV40 immortalized fallopian tube (FT-194, FT-190), SV40 immortalized ovarian surface epithelium (1816-575), low-grade serous adenocarcinoma (HEY), high-grade serous adenocarcinoma (TOV-1946), clear cell adenocarcinoma (TOV21G), cisplatin-sensitive high-grade serous adenocarcinoma (A2780-S) and cisplatin-resistant high-grade serous adenocarcinoma (A2780-CP), were prepared. Eight cell lines were submitted for isobaric tagging for relative and absolute quantification (iTRAQ®) differential expression analysis. Briefly, each of the eight secretomes were trypsin-digested and labeled with one of eight iTRAQ® 8-plex reagents and subsequently submitted for either two-dimensional capillary liquid chromatography direct data dependent peptide tandem mass spectrometry on an Orbitrap Velos system or one-dimensional mass spectrometry analysis. Western blot validation using an anti-CBLN2 antibody was used for protein validation. RESULTS: Overexpression of CBLN2 in A2708-CP ranged from 6.4 to 12.3 times greater when compared to ovarian and fallopian tube control cell lines and 5.4 times greater when to compared to the cisplatin-sensitive cell line A2780-S. Western Blot demonstrated a differentially expressed 24 kDa band amongst subtypes. CONCLUSIONS: CBLN2 is upregulated in the chemoresistant high grade serous carcinoma cell line A2780-CP compared to normal fallopian tube and ovarian surface epithelial cell lines. These results are promising for a marker for chemoresistance and further experiments in serum validation and characterization are warranted. The views expressed in this abstract are those of the author and do not reflect the official policy of the Department of Army/Navy/Air Force, Department of Defense, or U.S. Government. Citation Format: John D. Andersen, DO, CPT(P), MC, USA, Najerie S. McMillian, BSc, William R. Andersen, MS, MBA Sean Kimbro, PhD. CEREBELLIN-2 (CBLN2) IS DIFFERENTIALLY EXPRESSED IN OVARIAN CANCER SUBTYPES [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr GMM-016.