title: Intercellular transfer of proteins as identified by stable isotope labeling of amino acids in cell culture.
abstract: 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 of basic cellular processes and components of the nucleosome remodeling and deacetylase complex, including metastasis associated protein 3 and retinoblastoma-binding protein 7. In further analysis we find that retinoblastoma-binding protein 7 is a transcriptional activator of E-cadherin and that its intercellular transfer leads to decreased gene expression of downstream targets such as N-cadherin and vimentin. SILAC-generated data sets offer a valuable tool to identify and validate potential paracrine networks that may impact relevant biologic processes associated with phenotypic and genotypic signatures of health and disease.
authors.affiliation: Laboratory of Retrovirology, Division of Infectious Diseases, Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, Rhode Island 02903, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Jason M
authors.initials: JM
authors.lastname: Aliotta
authors.forename: John M
authors.initials: JM
authors.lastname: Asara
authors.forename: Qian
authors.initials: Q
authors.lastname: Wu
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dooner
authors.forename: Lynne D
authors.initials: LD
authors.lastname: Tucker
authors.forename: Alan
authors.initials: A
authors.lastname: Wells
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Quesenberry
authors.forename: Bharat
authors.initials: B
authors.lastname: Ramratnam
mesh_terms: D000596:Amino Acids; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D008168:Lung / Q000737:chemistry* / Q000166:cytology / Q000528:radiation effects; D008297:Male; D051379:Mice; D019899:Paracrine Communication / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000378:metabolism; D011506:Proteins / Q000032:analysis* / Q000378:metabolism; D040901:Proteomics / Q000379:methods*
chemical_list: D000596:Amino Acids; D011506:Proteins