Introduction and Objectives: Prostate cancer is a leading cause of cancer-related death in males. The current method of screening involves measuring serum prostate specific antigen (PSA), but it suffers from poor specificity and sensitivity. Other tests are invasive to the patients and not well tolerated. Early detection and the development of candidate biomarkers is a major goal. Here we use microarrays of Cluster of Differentiation (CD) antibodies to monitor difference in populations of peripheral blood mononuclear cells (PBMCs) between healthy and prostate cancer patients with varying stages of disease. Here we aim to develop a diagnostic test that detects clinically significant from clinically insignificant PCa with improved sensitivity and specificity that requires only a small sample (5-10mL) of venous blood.
Methods: Venous blood is collected from patients enrolled at the Sydney Adventist Hospital. PBMCs (lymphocytes, monocytes) are isolated on a Ficoll density gradient. 1x106 cells are incubated for 30 min on a cancer-specific microarray where immobilized CD antibodies “capture” cells expressing the corresponding CD surface antigens. Confocal microscopy and flow cytometry analysis is used to verify and validate significantly up-regulated and down-regulated proteins identified by antibody microarray technology.
Results: A meta-analysis was performed on 60 test samples, revealing a set of consistent and statistically significant expression patterns. Preliminary data identified a number of features that appear to separate different stages of malignancy. These were further validated using flow cytometry.
Conclusion: Based on the statistical analysis, we can conclude that the microarray can discriminate between cancer and healthy. The patterns of PBMC’s provide an immuno-phenotype that is diagnostic of the disease state.