Abstract 4207: Secreted proteins from breast cancer cell lines as a source of cancer biomarkers

Introduction: Breast cancer is a heterogeneous disease whose molecular diversity is not well reflected in clinical and microscopic markers used for prognostic information and treatment decisions. Traditionally, most biomarkers are based on tissue samples. To increase efficiency, precise liquid biopsies are needed to detect breast cancer at an early stage including its molecular phenotype, to monitor disease progression, and to predict treatment response. Cell line secretomes are enriched with proteins already linked to tumorigenesis, many of which will be present in biological fluids. Methods: Here, we studied the secreted proteins in conditioned media (CM) from two basal-like (HS-578, MB-231) and two luminal-like breast cancer cell lines (MCF-7, BT-474), using liquid chromatography-tandem mass spectrometry. The resulting data were analyzed using SearchGUI, PeptideShaker, Progenesis software and DAVID. Results: In total, 954 proteins were identified, of which 93 significantly differentially abundant (P-value ≤ 0.05 Mann-Whitney U, two or more peptides quantified) in the CM between basal-like and luminal-like cell lines. 76 proteins were more abundant in the CM from basal-like cell lines, including several proteins related to angiogenesis and extra-cellular matrix remodeling. Conclusion: This study shows the potential for using the secretome of breast cancer cell lines combined with mass-spectrometry for biomarker discovery. Citation Format: Even Birkeland, Monica Mannelqvist, Lars Andreas Akslen. Secreted proteins from breast cancer cell lines as a source of cancer biomarkers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4207. doi:10.1158/1538-7445.AM2015-4207