A proteomic study on human lung adenocarcinoma cell line A549 by 2-DE and MALDI-TOF-MS

Objective: To analyze protein profiles in human lung adenocarcinoma cell line A549 cell and to investigate molecular mechanism of pulmonary adenocarcinoma genesis at the level of proteomics. Methods: Two dimensional gel electrophoresis (2-DE) was used to separate totally soluble proteins extracted from A549 cell, and peptide mass fingerprintings (PMFs) were obtained and then some spots on 2-DE gels were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) combined with bioinformatics. Results: The average total number of proteins spots was 1138 ± 49, average paired spots 986 ± 32, and matched rate 85.8% among the three gels. 20 spots with high resolution and reproducibility were analyzed using MALDI-TOF-MS, 18 spots yielded PMFs, and 15 proteins were preliminarily identified and further classified into 7 categories based on their functions: Circled digit one enzymes related to cell metabolism: fructose-bisphosphate aldolase A, retinal dehydrogenase 1(RALDH1), pyridoxal kinase; Circled digit two cytoskeleton proteins: type II cytoskeletal 8(CK8) , tubulin beta-2 chain; Circled digit three proteins related to stress: protein disulfide-isomerase A3 (PDIA3); Circled digit four signal tranduction molecules: annexin A1(ANX1) and annexin A4(ANX2); Circled digit five chaperones: 60 ku heat shock protein(HSP60), heat shock protein beta-1, prohibitin (PHB); Circled digit six proteins related to transcription and translation: heterogeneous nuclear ribonucleoprotein H (hnRNP H); Circled digit seven others: Rgr protein, nucleophosmin (NPM), poly (rC)-binding protein 1 (PCBP1). Conclusion: A clear, well-resolved protein profile in A549 cell was obtained by 2-DE and 15 proteins were identified using PMFs.