title: Identification of proteins expressed differently among surgically resected stage I lung adenocarcinomas.
abstract: BACKGROUND
  Among patients with surgically resected stage I lung adenocarcinoma, some succumb to early recurrence, while others survive for more than 5 years. Few markers to predict prognoses in these patients have been accepted. Recent advances in proteomic methodologies offer a unique chance to identify new candidate biomarkers. The aim of this study is to find differences in protein expression in resected lung cancer tissue of stage I adenocarcinoma from patients with no recurrence for more than 5 years and from those with early recurrence.
  
  
  METHODS
  Lung cancer tissues were obtained from 15 patients with pathologically confirmed stage I adenocarcinoma. The patients were divided into two groups, those with recurrence within 36 months (early recurrence group, n=9) and those that were disease-free for over 5 years (disease free group, n=6). Tissue proteins were separated by a two-dimensional electrophoresis long gel system (30 × 40 cm) with set ranges (3-10 NL) and examined by nano-LC-ESI-MS/MS. Western blot assays were performed to validate these proteins.
  
  
  RESULTS
  Twelve protein spots were up-regulated and 8 were down-regulated in the disease-free group as compared with the recurrence group. Of the 12 up-regulated proteins, haptoglubin, tau-tubulin kinase-2 (TTBK2), thymidine phosphorylase, annexin-1, PIN1, CAPG, and SEC23 were validated by Western blot. Among the 8 down-regulated proteins, serpinB6 and trangelin-2 were validated.
  
  
  CONCLUSIONS
  A total of 9 differentially expressed proteins were successfully extracted, identified, and confirmed from stage I lung adenocarcinoma tissues. The increased or decreased expression of these proteins according to prognosis may be the basis for further studies of proteomics in developing prognostic biomarkers.
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
authors.forename: Eun Sil
authors.initials: ES
authors.lastname: Ha
authors.forename: Seonyoung
authors.initials: S
authors.lastname: Choi
authors.forename: Kwang Ho
authors.initials: KH
authors.lastname: In
authors.forename: Seung Hyeun
authors.initials: SH
authors.lastname: Lee
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Lee
authors.forename: Sang Yeub
authors.initials: SY
authors.lastname: Lee
authors.forename: Je Hyeong
authors.initials: JH
authors.lastname: Kim
authors.forename: Chol
authors.initials: C
authors.lastname: Shin
authors.forename: Jae Jeong
authors.initials: JJ
authors.lastname: Shim
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Kang
authors.forename: Sohee
authors.initials: S
authors.lastname: Phark
authors.forename: Donggeun
authors.initials: D
authors.lastname: Sul
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D015870:Gene Expression; D006801:Humans; D007525:Isoelectric Focusing; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000378:metabolism*; D009367:Neoplasm Staging; D020543:Proteome / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; D020543:Proteome