Proteomic analysis of lung adenocarcinoma: identification of a highly expressed set of proteins in tumors.

PURPOSE The goal of this study was to identify potential protein markers in lung adenocarcinomas. EXPERIMENTAL DESIGN A series of 93 lung adenocarcinomas (64 stage I and 29 stage III) and 10 uninvolved lung samples were examined for quantitative differences in protein expression using two-dimensional PAGE. Candidate proteins were identified using matrix-assisted laser desorption/ionization mass spectrometry or peptide sequencing. The levels of the individual isoforms of nine proteins found to be overexpressed in the lung tumors were examined. Potential mechanisms for overexpression were examined by comparing mRNA expression levels, assessed using oligonucleotide arrays, to the protein values in the same samples. RESULTS Antioxidant enzyme AOE372, ATP synthase subunit d (ATP5D), beta1,4-galactosyltransferase, cytosolic inorganic pyrophosphatase, glucose-regulated M(r) 58,000 protein, glutathione-S-transferase M4, prolyl 4-hydroxylase beta subunit, triosephosphate isomerase, and ubiquitin thiolesterase (UCHL1) were identified as being significantly overexpressed in lung adenocarcinomas. The expression of these proteins was increased from 1.4- to 10.6-fold as compared with uninvolved lung tissue. The expression of the individual protein isoforms was correlated with 10 clinicopathological variables as well as with each gene's mRNA level in the same sample. Both isoforms of glucose-regulated M(r) 58,000 protein were found to be significantly correlated with their mRNA expression profiles (P < 0.05), indicating that increased transcription likely underlies the increased expression of these proteins. CONCLUSIONS Two-dimensional PAGE and mass spectrometry can identify proteins showing increased expression in lung adenocarcinoma. The association of specific isoforms of these proteins with clinical variables and understanding the regulation of their expression will aid in determination of their potential use as biomarkers in this cancer.

[1]  R. Kuick,et al.  Data base analysis of protein expression patterns during T-cell ontogeny and activation. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[2]  R D Kuick,et al.  A two‐dimensional electrophoresis‐related laboratory information processing system: Spot matching , 1991, Electrophoresis.

[3]  S. Goodman,et al.  PGP9.5 as a candidate tumor marker for non-small-cell lung cancer. , 1999, The American journal of pathology.

[4]  G Rennert,et al.  Organ-specific molecular classification of primary lung, colon, and ovarian adenocarcinomas using gene expression profiles. , 2001, The American journal of pathology.

[5]  R. Kuick,et al.  A comparison of some adjustment techniques for use with quantitative spot data from two‐dimensional gels , 1987 .

[6]  M. Stefanini.  Enzymes, isozymes, and enzyme variants in the diagnosis of cancer. A short review , 1985, Cancer.

[7]  A. Palotie,et al.  Structures of the human gene for the protein disulfide isomerase-related polypeptide ERp60 and a processed gene and assignment of these genes to 15q15 and 1q21. , 1997, Genomics.

[8]  M. Schwartz.  Enzyme patterns in cancer. , 1977, Annals of clinical and laboratory science.

[9]  Thomas E. Creighton,et al.  Protein structure : a practical approach , 1997 .

[10]  F. Peale,et al.  Detection of novel gene expression in paraffin‐embedded tissues by isotopic in situ hybridization in tissue microarrays , 2001, The Journal of pathology.

[11]  C. Merril,et al.  A rapid sensitive silver stain for polypeptides in polyacrylamide gels. , 1981, Analytical biochemistry.

[12]  T. Hirano,et al.  Characterization of gene expression in clinical lung cancer materials by two‐dimensional polyacrylamide gel electrophoresis , 1994, Electrophoresis.

[13]  R. Álvarez-Sala Walther,et al.  [Tumor markers in lung cancer]. , 2001, Anales de medicina interna.

[14]  T. Tanaka,et al.  Molecular cloning of the human glucose-regulated protein ERp57/GRP58, a thiol-dependent reductase. Identification of its secretory form and inducible expression by the oncogenic transformation. , 1995, European journal of biochemistry.

[15]  T. Petty,et al.  Five year survival and later outcome of patients with X-ray occult lung cancer detected by sputum cytology. , 2000, Lung cancer.

[16]  S. Gygi,et al.  Correlation between Protein and mRNA Abundance in Yeast , 1999, Molecular and Cellular Biology.

[17]  S. Hanash,et al.  Proteomics-based identification of protein gene product 9.5 as a tumor antigen that induces a humoral immune response in lung cancer. , 2001, Cancer research.

[18]  L. Maquat,et al.  Characterization of the functional gene and several processed pseudogenes in the human triosephosphate isomerase gene family , 1985, Molecular and cellular biology.

[19]  G. Auer,et al.  Cancer proteomics: From identification of novel markers to creation of artifical learning models for tumor classification , 2000, Electrophoresis.

[20]  T. Ørntoft,et al.  Gene expression profiling: monitoring transcription and translation products using DNA microarrays and proteomics , 2000, FEBS letters.

[21]  J. Kononen,et al.  Tissue microarrays for high-throughput molecular profiling of tumor specimens , 1998, Nature Medicine.

[22]  S. Yasuda,et al.  Detection of tumor cells in the portal and peripheral blood of patients with colorectal carcinoma using competitive reverse transcriptase‐polymerase chain reaction , 2001, Cancer.

[23]  C. Bennett,et al.  The 28K protein in urinary bladder, squamous metaplasia and urine is triosephosphate isomerase. , 1997, Clinical biochemistry.

[24]  O. Stoeltzing,et al.  Multiple molecular marker testing (p53, C-Ki-ras, c-erbB-2) improves estimation of prognosis in potentially curative resected non-small cell lung cancer , 2000, British Journal of Cancer.

[25]  J. Wu.  Review of circulating tumor markers: from enzyme, carcinoembryonic protein to oncogene and suppressor gene. , 1999, Annals of clinical and laboratory science.