MALDI MS profiles distinguish ER-negative breast cancers from lung adenocarcinoma

Abstract

Background: There is an unmet need for tissue-specific biomarkers that distinguish estrogen receptor (ER)negative breast cancers from primary lung adenocarcinomas. Methods: To identify proteins that differ between primary breast and lung cancers, frozen resected samples collected from 10 ER-negative breast and 18 lung adenocarcinomas patients were analyzed using Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry (MS). Results: MALDI MS profiles were significantly different between primary breast and lung adenocarcinomas. Importantly, 4 peaks that differentially expressed between breast and lung adenocarcinomas correctly predicted the class label of a lung metastasis of breast cancer. A peak at m/z 10,093, which was significantly overexpressed in primary lung cancer, was identified as S100A6. According to immunohistochemistry study using commercially available tissue microarray slides, S100A6 expression was significantly lower in breast cancer samples than in lung adenocarcinomas samples. Conclusion: We identified MALDI MS profiles that may distinguish primary lung adenocarcinoma from ERnegative breast adenocarcinoma. S100A6 was identified as one of the informative peaks in the MALDI MS profiles. © 2013 Reyzer ML, et al.