Comparative Metabolite Extraction Protocols from Breast Cancer Mouse Lung Tissue for LC-MS/MS Analysis

Abstract

Triple-negative breast cancer (TNBC) stands out for its heightened invasiveness, leading to distant metastasis in nearly 46% of cases, with common targets being the brain, lungs, and bones. This subtype is associated with significantly shorter median survival compared to other breast cancer types. Analyzing metabolic compounds in lung tissues affected by breast cancer metastasis provides valuable insights into biological information and regulatory processes. Despite the recognized severity of TNBC spreading to other sites, there are limited reported studies investigating metabolome information in distant organ tissues, particularly the lungs. Therefore, accurately quantifying the abundance of metabolites requires careful extraction procedures. This study aims to investigate and compare extraction protocols for lung tissue metabolites in TNBC mice using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Left lung tissues were collected from mice xenografted with breast cancer. Three different extraction methods were evaluated to assess their metabolite coverage and biochemical compound classes. Our findings revealed distinct differences in metabolite compositions among the three methods. The extraction solvent comprising isopropanol, acetonitrile, and water in a 3:2:2 ratio proved most suitable for studying breast cancer metastasis to lung tissues. This extraction solvent could serve as a protocol for future studies analyzing the lung cancer metabolome in mice.