Quantitative Fluorescence Imaging Analysis for Cancer Biomarker Discovery: Application to β-Catenin in Archived Prostate Specimens

• Published in: Cancer epidemiology, biomarkers & prevention Vol. 16; no. 7; pp. 1371 - 1381
• Main Authors: DALI HUANG, CASALE, George P, JUN TIAN, WEHBI, Nizar K, ABRAHAMS, Neil A, KALEEM, Zahid, SMITH, Lynette M, JOHANSSON, Sonny L, ELKAHWAJI, Johny E, HEMSTREET, George P
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.07.2007
• Subjects: Aged; Archives; beta Catenin - metabolism; Biological and medical sciences; Biomarkers, Tumor - metabolism; Case-Control Studies; Cross-Sectional Studies; Fluorescence; Humans; Image Processing, Computer-Assisted; Immunoenzyme Techniques; Male; Medical sciences; Microscopy, Fluorescence - methods; Middle Aged; Nephrology. Urinary tract diseases; Prognosis; Prostate; Prostate - metabolism; Prostate - pathology; Prostatectomy; Prostatic Hyperplasia - metabolism; Prostatic Hyperplasia - pathology; Prostatic Hyperplasia - surgery; Prostatic Neoplasms - metabolism; Prostatic Neoplasms - pathology; Prostatic Neoplasms - surgery; Protein Array Analysis; Proteometry; Reproducibility of Results; Risk Factors; Sensitivity and Specificity; Staining and Labeling; Survival Rate; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland; β-Catenin; Human; Nephrology; Urinary system disease; Prostate disease; Fluorescence; Biological marker; Biological indicator; Malignant tumor; Urology; Cancerology; β Catenin; Diagnosis; Male genital diseases; Prostate cancer; Public health; Quantitative analysis
• ISSN: 1055-9965; 1538-7755
• DOI: 10.1158/1055-9965.EPI-06-0718

The surprising disparity between the number of protein-encoding genes (∼30,000) in the human genome and the number of proteins (∼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 flourescence imaging analysis (QFIA) for accurate, reproducible quantification of proteins in slide-mounted tissues. The method has been validated for the analysis of β-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 β-catenin in methacarn-fixed prostate specimens analyzed by reverse-phase protein array analysis and QFIA ( r = 0.97). QFIA of β-catenin in formaldehyde-fixed tissues correlated directly with β-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 β-catenin as a potential field marker for PC. Receiver operating characteristic plots revealed that β-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 β-catenin expression as a biomarker for PC. (Cancer Epidemiol Biomarkers Prev 2007;16(7):1371–81)