We tracked the extracellular fate of proteins of pulmonary origin using the technique of
stable isotope labeling of amino acids in cell culture (SILAC) in cell-impermeable Transwell
culture systems. We find that irradiation to murine lung and lung-derived cells induces their
release of proteins that are capable of entering neighboring cells, including primary murine
bone marrow cells as well as prostate cancer and hematopoietic cell lines. The functional
classification of transferred proteins was broad and included transcription factors, mediators …