Proteomics-based identification of proteins secreted in apical surface fluid of squamous metaplastic human tracheobronchial epithelial cells cultured by three-dimensional organotypic air-liquid interface method.
Squamous cell carcinoma in the lung originates from bronchial epithelial cells that acquire increasingly abnormal phenotypes. Currently, no known biomarkers are clinically efficient for the early detection of premalignant lesions and lung cancer. We sought to identify secreted molecules produced from squamous bronchial epithelial cells cultured with organotypic culture methods. We analyzed protein expression patterns in the apical surface fluid (ASF) from aberrantly differentiated squamous metaplastic normal human tracheobronchial epithelial (NHTBE) and mucous NHTBE cells. Comparative two-dimensional PAGE analysis revealed 174 unique proteins in the ASF of squamous NHTBE cells compared with normal mucociliary differentiated NHTBE cells. Among them, 64 well-separated protein spots were identified by liquid chromatography-tandem mass spectrometry, revealing 22 different proteins in the ASF from squamous NHTBE cells. Expression of six of these proteins [SCC antigen 1 (SCCA1), SCC antigen 2 (SCCA2), S100A8, S100A9, Annexin I, and Annexin II] in the squamous NHTBE cells was further confirmed with immunoblot analysis. Notably, SCCA1 and SCCA2 were verified as being expressed in squamous metaplastic NHTBE cells but not in normal mucous NHTBE or normal bronchial epithelium. Moreover, SCCA1 and SCCA2 expression increased in in vitro lung carcinogenesis model cell lines with increasing malignancy. In summary, we identified proteins that are uniquely secreted from squamous metaplastic primary human bronchial epithelial cells cultured by the organotypic air-liquid interface method. These ASF proteins may be used to detect abnormal lesions in the lung without collecting invasive biopsy specimens.
Kim
Seung-Wook
SW
Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030-4009, USA. jskoo@mdanderson.org
Cheon
Kyounga
K
Kim
Chang-Hoon
CH
Yoon
Joo-Heon
JH
Hawke
David H
DH
Kobayashi
Ryuji
R
Prudkin
Ludmila
L
Wistuba
Ignacio I
II
Lotan
Reuben
R
Hong
Waun Ki
WK
Koo
Ja Seok
JS
D000388:Air; D000951:Antigens, Neoplasm / Q000096:biosynthesis; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008967:Molecular Biology / Q000379:methods*; D009362:Neoplasm Metastasis; D040081:Protein Array Analysis; D011506:Proteins / Q000737:chemistry*; D040901:Proteomics / Q000379:methods*; D015843:Serpins / Q000096:biosynthesis; D013499:Surface Properties; D014134:Tracheal Neoplasms / Q000378:metabolism*
D000951:Antigens, Neoplasm; D011506:Proteins; D015843:Serpins; C051072:squamous cell carcinoma-related antigen