title: Stage-specific analysis of plasma protein profiles in ovarian cancer: Difference in-gel electrophoresis analysis of pooled clinical samples.
abstract: BACKGROUND
  Ovarian cancer is the leading cause of death from gynecological cancer. Non-specific symptoms early in disease and the lack of specific biomarkers hinder early diagnosis. Multi-marker blood screening tests have shown promise for improving identification of early stage disease; however, available tests lack sensitivity, and specificity.
  
  
  METHODS
  In this study, pooled deeply-depleted plasma from women with Stage 1, 2 or 3 ovarian cancer and healthy controls were used to compare the 2-dimensional gel electrophoresis (2-DE) protein profiles and identify potential novel markers of ovarian cancer progression.
  
  
  CONCLUSIONS
  Stage-specific variation in biomarker expression was observed. For example, apolipoprotein A1 expression is relatively low in control and Stage 1, but shows a substantial increase in Stage 2 and 3, thus, potential of utility for disease confirmation rather than early detection. A better marker for early stage disease was tropomyosin 4 (TPM4). The expression of TPM4 increased by 2-fold in Stage 2 before returning to "normal" levels in Stage 3 disease. Multiple isoforms were also identified for some proteins and in some cases, displayed stage-specific expression. An interesting example was fibrinogen alpha, for which 8 isoforms were identified. Four displayed a moderate increase at Stage 1 and a substantial increase for Stages 2 and 3 while the other 4 showed only moderate increases.
  
  
  CONCLUSIONS
  Herein is provided an improved summary of blood protein profiles for women with ovarian cancer stratified by stage.
authors.affiliation: Zoetis, Veterinary Medicine Research and Development, Melbourne, Australia.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Bailey
authors.forename: Kristy L
authors.initials: KL
authors.lastname: Shield-Artin
authors.forename: Karen
authors.initials: K
authors.lastname: Oliva
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ayhan
authors.forename: Simone
authors.initials: S
authors.lastname: Reisman
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Rice
keywords: Difference in-gel electrophoresis; disease stage; ovarian cancer; protein depletion