Novel human cancer biomarkers identified by blood cells gene expression

4530 Background: Gene signatures from malignant tumors have prognostic and diagnostic importance. Little is known, however, about the gene expression profiles of blood cells that circulate throughout the body coming in close contact with host tissues and cells. We hypothesized that such a blood analysis may provide diagnostic clues for different types and stages of cancer. Methods: Total RNA’s from blood of 34 patients (pts) with genitourinary cancers (10 testicular, 9 renal, 10 superficial bladder and 5 metastatic bladder) and of 10 healthy subjects were profiled on Affymetrix U133Plus2.0 GeneChips. Differentially expressed genes were identified using the non-parametric, Wilcoxon-Mann-Whitney test, some confirmed by real time RT-PCR, and analyzed by Hierarchical Clustering to assess the correlation between samples. Logistic regression and two-gene ratios were used to assess the ability of linear combinations of specific transcripts to appropriately group the samples. The diagnostic power for each combina...