title: Quantitative fluorescence imaging analysis for cancer biomarker discovery: application to beta-catenin in archived prostate specimens.
abstract: The surprising disparity between the number of protein-encoding genes ( approximately 30,000) in the human genome and the number of proteins ( approximately 300,000) in the human proteome has inspired the development of translational proteomics aimed at protein expression profiling of disease states. Translational proteomics, which offers the promise of early disease detection and individualized therapy, requires new methods for the analysis of clinical specimens. We have developed quantitative fluorescence imaging analysis (QFIA) for accurate, reproducible quantification of proteins in slide-mounted tissues. The method has been validated for the analysis of beta-catenin in archived prostate specimens fixed in formalin. QFIA takes advantage of the linearity of fluorescence antibody signaling for tissue epitope content, a feature validated for beta-catenin in methacarn-fixed prostate specimens analyzed by reverse-phase protein array analysis and QFIA (r = 0.97). QFIA of beta-catenin in formaldehyde-fixed tissues correlated directly with beta-catenin content (r = 0.86). Application of QFIA in a cross-sectional study of biopsies from 42 prostate cancer (PC) cases and 42 matched controls identified beta-catenin as a potential field marker for PC. Receiver operating characteristic plots revealed that beta-catenin expression in the normal-appearing acini of cancerous glands identified 42% (95% confidence intervals, 26-57%) of cancer cases, with 88% (95% confidence intervals, 80-96%) specificity. The marker may contribute to a PC biomarker panel. In conclusion, we report the development and validation of a new method for fluorescence quantification of proteins in archived tissues and its application to archived specimens for an evaluation of beta-catenin expression as a biomarker for PC.
authors.affiliation: Department of Surgery, Urologic Surgery Section, 982360 Nebraska Medical Center, Omaha, NE 68198-2360, USA.
authors.forename: Dali
authors.initials: D
authors.lastname: Huang
authors.forename: George P
authors.initials: GP
authors.lastname: Casale
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.forename: Nizar K
authors.initials: NK
authors.lastname: Wehbi
authors.forename: Neil A
authors.initials: NA
authors.lastname: Abrahams
authors.forename: Zahid
authors.initials: Z
authors.lastname: Kaleem
authors.forename: Lynette M
authors.initials: LM
authors.lastname: Smith
authors.forename: Sonny L
authors.initials: SL
authors.lastname: Johansson
authors.forename: Johny E
authors.initials: JE
authors.lastname: Elkahwaji
authors.forename: George P
authors.initials: GP
authors.lastname: Hemstreet
mesh_terms: D000368:Aged; D001109:Archives; D014408:Biomarkers, Tumor / Q000378:metabolism*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods*; D008875:Middle Aged; D011379:Prognosis; D011467:Prostate / Q000378:metabolism / Q000473:pathology; D011468:Prostatectomy; D011470:Prostatic Hyperplasia / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D040081:Protein Array Analysis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D015996:Survival Rate; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; D051176:beta Catenin