ABSTRACT: To study feasibility of gene expression profiling from FFPE tissues using NuGen amplified mRNA hybridized on Affymetrix GeneChip Human Gene 1.0 ST arrays, we designed a pilot study utilizing samples from prostate cancer cohort. We selected samples from large-scale epidemiologic studies and clinical trials representative of a wide variety of fixation times, block ages and block storage conditions. We profiled seven paired tumor and adjacent normal prostate tissue samples from three patients with Gleason score 8, one with Gleason score 7 and three with Gleason 6 disease. 11 samples had two or three technical replicates.
Project description:To study feasibility of gene expression profiling from FFPE tissues using NanoString nCounter platform, we designed a pilot study utilizing samples from prostate cancer cohort. We selected samples from large-scale epidemiologic studies and clinical trials representative of a wide variety of fixation times, block ages and block storage conditions. five paired tumor and adjacent normal prostate tissue speciemens with technical replicates
Project description:PSA screening has led to enormous overtreatment of prostate cancer, due to the inability to distinguish potentially lethal disease at diagnosis. We reasoned that by identifying an mRNA signature of Gleason grade, the best predictor of prognosis, we could improve prediction of lethal disease among men with moderate Gleason 7 tumors, the most common grade, and most indeterminate in terms of prognosis. Using the complementary DNA (cDNA)M-bM-^@M-^Smediated annealing, selection, extension, and ligation assay, we measured the mRNA expression of 6,100 genes in prostate tumor tissue in the Swedish Watchful Waiting cohort (N=358) and PhysiciansM-bM-^@M-^Y Health Study (PHS; N=109). We developed an mRNA signature of Gleason comparing individuals with Gleason M-bM-^IM-$6 to those with Gleason M-bM-^IM-%8 tumors, and applied the model among Gleason 7 cases to discriminate lethal cases. We built a157-gene signature using the Swedish data that predicted Gleason with low misclassification (AUC=0.91); when this signature was tested in the PHS validation set, the discriminatory ability remained high (AUC=0.94). In men with Gleason 7 tumors, who were excluded from the model building, the signature significantly improved the prediction of lethal disease beyond knowing whether the Gleason score was 4+3 or 3+4 (p=0.006). Our expression signature and the genes identified may improve our understanding of the de-differentiation process of prostate tumors. Additionally, the signature may have clinical applications among men with Gleason 7, by further estimating their risk of lethal prostate cancer and thereby guiding therapy decisions to improve outcomes and reduce overtreatment. 198 cases from the population-based Swedish-Watchful Waiting cohort. The cohort consists of men with localized prostate cancer (clinical stage T1-T2, Mx, N0); expression profiles from tumors with Gleason M-bM-^IM-%8 (N=89) were compared to those from tumors with Gleason M-bM-^IM-$6 (N=109)
Project description:Prostate cancer is one of the most frequently diagnosed cancers in men. Prostate tumor staging and disease aggressiveness are evaluated based on the Gleason scoring system, which is further used to direct clinical intervention. The Gleason scoring system provides an estimate of tumor aggressiveness through quantitation of the serum level of prostate specific antigen (PSA) and histologic assessment of Grade Group, determined by the Gleason Grade of the tumor specimen. To improve our understanding of the proteomic characteristics differentiating low- versus high-grade prostate cancer tumors, we performed a deep proteomic characterization of laser microdissected epithelial and stromal subpopulations from surgically resected tissue specimens from patients with Gleason 6 (n=23 specimens from n=15 patients) and Gleason 9 (n=15 specimens from n=15 patients) prostate cancer via quantitative high-resolution liquid chromatography-tandem mass spectrometry analysis.
Project description:From over 300 patients two groups were selected which had prostate tumors with either well differentiated (WD) or poorly differentiated (PD) after radical Prostatectomy. The PD group had Gleason score 8-9, seminal vesicle invasion, and poorly differentiated tumor cells; the WD group had Gleason score 6-7, no seminal vesicle invasion, and well to moderately differentiated tumor cells. LCM compatible specimens were selected from age and race (Caucasians) matched PD or WD patients with no family history of CaP. Matching normal epithelal cells were also selected for the analysis. From 40 patients specimens were obtained under an IRB-approved protocol from patients treated with radical prostatectomy (RP) at Walter Reed Army Medical Center (WRAMC).
Project description:Screening of differentially expressed genes between benign and prostate tumors with respect to different prostate cancer gleason score 6 and 8 Keywords: disease subtype analysis
Project description:Although many genes have been proposed to be involved in prostate carcinogenesis, no single gene or gene profile has shown to have prognostic value. The main challenge for clinical management is to distinguish slowly growing tumors from those that will relapse. In this study, we compared expression profiles of 18 prostate samples (7 with Gleason 6, 8 with Gleason 7 and 3 with Gleason score equal or higher than 8) and 5 non-neoplastic prostate samples, using the GeneChip® Human Exon Array 1.0 ST of Affymetrix. Microarray analysis revealed 99 genes showing statistically significant differences among tumors with Gleason score 6, 7 and 8. In addition, mRNA expression of 29 selected genes was analyzed by qRT-PCR with microfluidic cards in an extended series of 30 prostate tumors. From these, 29 were selected to be validated and the differential expression of 18 of them (62%) was independently confirmed by quantitative real-time RT-PCR (14 upregulated and 4 downregulated in higher Gleason scores) in the extended series. This list was further narrowed down to 12 genes that were differentially expressed in tumors with Gleason score of 6-7 vs 8. Finally, the protein levels of two genes from the 12-gene signature (SEC14L1 and TCEB1) were additionally validated by immunohistochemistry. Strong protein levels of both genes were correlated with Gleason score, stage, and PSA progression. We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process.
Project description:The identification of novel oncogenic and druggable targets in patient subgroups with poor prognosis may help to develop corresponding targeted therapy approaches. Microarray data analyses of 59 prostate cancer and 39 benign tissue samples revealed major transcriptional differences. More than 5.000 genes were identified to be differentially expressed between matched tumor and benign samples. In the prostate cancer samples we identified 144 differentially expressed associated with Gleason pattern. Illumina microarray experiments were done from of 59 prostate cancer and 39 matched benign tissue samples. We analyzed for differentially expressed genes between tumor and benign tissues, and between tumors with higher Gleason patter (4+3 and higher) against lower Gleason patter (3+4 and lower).
Project description:Although many genes have been proposed to be involved in prostate carcinogenesis, no single gene or gene profile has shown to have prognostic value. The main challenge for clinical management is to distinguish slowly growing tumors from those that will relapse. In this study, we compared expression profiles of 18 prostate samples (7 with Gleason 6, 8 with Gleason 7 and 3 with Gleason score equal or higher than 8) and 5 non-neoplastic prostate samples, using the GeneChip® Human Exon Array 1.0 ST of Affymetrix. Microarray analysis revealed 99 genes showing statistically significant differences among tumors with Gleason score 6, 7 and 8. In addition, mRNA expression of 29 selected genes was analyzed by qRT-PCR with microfluidic cards in an extended series of 30 prostate tumors. From these, 29 were selected to be validated and the differential expression of 18 of them (62%) was independently confirmed by quantitative real-time RT-PCR (14 upregulated and 4 downregulated in higher Gleason scores) in the extended series. This list was further narrowed down to 12 genes that were differentially expressed in tumors with Gleason score of 6-7 vs 8. Finally, the protein levels of two genes from the 12-gene signature (SEC14L1 and TCEB1) were additionally validated by immunohistochemistry. Strong protein levels of both genes were correlated with Gleason score, stage, and PSA progression. We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. 23 Samples were analyzed.