Bronchiectasis Nontuberculous mycobacterium (NTMnb) infection is an emerging health problem in breast cancer (BCa) patients. We measured sera exosome proteome in BCa-NTMnb subjects and controls by Mass Spectroscopy. Extracellular matrix protein 1 (ECM1) was detected exclusively in the circulating exosomes of 82% of the BCa-NTMnb cases. Co-culture of ECM1+ exosomes with normal human mammary epithelial cells induced epithelial to mesenchymal transition accompanied by increased Vimentin/CDH1 expression ratio and Glutamate production. Co-culture of the ECM1+ exosomes with normal human T cells modulated their cytokine production. The ECM1+ exosomes were markedly higher in sera obtained from BCa-NTMnb subjects. Exclusive expression of APN, APOC4 and AZGP1 was evident in the circulating exosomes of these BCa-NTMnb cases, which predicts disease prevalence independent of the body max index in concert with ECM1. Monitoring ECM1, APN, APOC4 and AZGP1 in the circulating exosomes could be beneficial for risk assessment, monitoring and surveillance of BCa-NTMnb.
Keywords: ECM1; biomarker; breast cancer; exosomes; nontuberculous Mycobacterium.