Project description:Surgery still remains the mainstay of treatment for localized colorectal cancer. However, nearly 30% of patients with localized colorectal cancer (stage II and stage III) will present with recurrence. Tumor progression is mediated by both intrinsic genetic changes and by extrinsic epigenetic and host environmental factors, including interactions with the immune system. Several studies demonstrated that tumor infiltrating memory T-cells and type, density and location of infiltrating T cells are better predictors of disease-free survival in patients with CRC compared to the standard TNM staging. These data suggest that tumor invasion and progression are more accurately predicted by immune response in the primary tumor. In addition, mismatch repair (MMR)-deficient tumors are characterized a priori by a higher frequency of tumor infiltrating lymphocytes and are associated with significantly improved prognosis. Recently, Stotz et al showed that the preoperative lymphocyte to monocyte ratio in peripheral blood samples predicts clinical outcome in patients with stage III colon cancer. So far there is no comprehensive analysis of the immune-landscape in CRC.
The aim of the current project is to identify a comprehensive panel of immunomarkers in localized colorectal cancer (stage II and stage III) applicable for the detection of patients at high risk of recurrence. For the first time, specific tumor-infiltrating immune cells, mismatch repair protein expression in tumor tissue and preoperative blood based inflammatory markers from routine blood counts in corresponding peripheral blood samples and known clinicopathological features will be correlated with outcome in 300 localized CRC patients.
Project description:Genome-wide association studies (GWAS) have revolutionized the field of cancer genetics, but the causal links between increased genetic risk and onset/progression of disease processes remain to be identified. Here we report the first step in such an endeavor for prostate cancer. We provide a comprehensive annotation of the 77 known risk loci, based upon highly correlated variants in biologically relevant chromatin annotations- we identified 727 such potentially functional SNPs. We also provide a detailed account of possible protein disruption, microRNA target sequence disruption and regulatory response element disruption of all correlated SNPs at r^2≥0.5. Greater than 88% of the 727 SNPs fall within putative enhancers, many of which alter critical residues in the response elements of transcription factors known to be involved in prostate biology. We define as risk enhancers those regions with enhancer chromatin biofeatures in prostate-derived cell lines with prostate-cancer correlated SNPs. To aid in the identification of these enhancers, we performed genomewide ChIP-seq for H3K27-acetylation, a mark of actively engaged enhancer regions, as well as the transcription factor TCF7L2. We analyzed in depth three variants in risk enhancers, two of which show significantly altered androgen sensitivity in LNCaP cells. This includes rs4907792, that is in linkage disequilibrium (r^2=0.91) with an eQTL for NUDT11 (on the X chromosome) in prostate tissue, and rs10486567, the index SNP in intron 3 of the JAZF1 gene on chromosome 7. Rs4907792 is within a critical residue of a strong consensus androgen response element that is interrupted in the protective allele, resulting in a 56% decrease in its androgen sensitivity, whereas rs10486567 affects both NKX3-1 and FOXA-AR motifs where the risk allele results in a 39% increase in basal activity and a 28% fold-increase in androgen stimulated enhancer activity. Identification of such enhancer variants and their potential target genes represents a preliminary step in connecting risk to disease process. ChIP-seq analysis of H3K27Ac in LNCaP charcoal-stripped serum, H3K27Ac in LNCaP charcoal-stripped serum +DHT, TCF7L2 in LNCaP
Project description:Prostate cancer (PCa) is the leading cancer among men in the United States, with genetic factors contributing to ~42% of the susceptibility to PCa. To understand the causal genetic factors associated with PCa, we have focused on a PCa risk region located at 7p15.2. We performed Hi-C analysis and demonstrated that this region has long range interactions with the HOXA locus, located ~873 kb away. Using the CRISPR/Cas9 system, we deleted a 4 kb region encompassing several prostate cancer risk-associated SNPs and performed RNA-seq to investigate transcriptomic changes in RWPE1 prostate cells lacking the regulatory element. Our results suggest that the risk element affects the expression of HOXA13 and HOTTIP, but not other genes in the HOXA locus, via a repressive loop. Forced expression of HOXA13 was also performed to gain insight into the mechanisms by which this risk element affects prostate cancer risk.
Project description:Characterization of the prostate cancer transcriptome and genome has identified chromosomal rearrangements and copy number gains/losses, including ETS gene fusions, PTEN loss and androgen receptor (AR) amplification, that drive prostate cancer development and progression to lethal, metastatic castrate resistant prostate cancer (CRPC)1. As less is known about the role of mutations2-4, here we sequenced the exomes of 50 lethal, heavily-pretreated metastatic CRPCs obtained at rapid autopsy (including three different foci from the same patient) and 11 treatment naïve, high-grade localized prostate cancers. We identified low overall mutation rates even in heavily treated CRPC (2.00/Mb) and confirmed the monoclonal origin of lethal CRPC. Integrating exome copy number analysis identified disruptions of CHD1, which define a subtype of ETS? prostate cancer. Similarly, we demonstrate that ETS2, which is deleted in ~1/3 of CRPCs (commonly through TMPRSS2:ERG fusions), is a prostate cancer tumor suppressor that can also be deregulated through mutation. Further, we identified recurrent mutations in multiple chromatin/histone modifying genes, including MLL2 (mutated in 8.6% of prostate cancers), and demonstrate interaction of the MLL complex with AR, which is required for AR mediated signaling. We also identified novel recurrent mutations in the AR collaborating factor FOXA1, which is mutated in 5 of 147 (3.4%) prostate cancers (both untreated localized prostate cancer and CRPC) , and showed that mutated FOXA1 represses androgen signaling and increases tumor growth in vitro and in vivo. Proteins that physically interact with AR, such as the ERG gene fusion product, FOXA1, MLL2, UTX, and ASXL1 were found to be mutated in CRPC, suggesting novel drivers of prostate cancer progression and potential resistance mechanisms to anti-androgen therapies. In summary, we describe the mutational landscape of a heavily treated metastatic cancer, identify novel mechanisms of AR signaling deregulated in prostate cancer, and prioritize candidates for future study. Gene expression profiling and array CGH (aCGH) was performed on matched benign prostate tissues (n=28), localized prostate cancer (n=59), and metastatic castrate resistant prostate cancer (CRPC, n=35). For gene expression profiling, frozen prostate tissue samples (channel 2), were hybridized against a commercial pool of benign prostate tissue (Clontech, channel 1). For aCGH, frozen prostate tissue samples (channel 2) were hybridized against a commerical sample of Human Male Genomic DNA (Promega, channel 1).
Project description:There are remarkable disparities among patients of different races with prostate cancer; however, the mechanism underlying this difference remains unclear. Here, we present a comprehensive landscape of the transcriptome profiles of 14 primary prostate cancers and their paired normal counterparts from the Chinese population using RNA-seq, revealing tremendous diversity across prostate cancer transcriptomes with respect to gene fusions, long noncoding RNAs (long ncRNA), alternative splicing and somatic mutations. Three of the 14 tumors (21.4%) harbored a TMPRSS2-ERG fusion, and the low prevalence of this fusion in Chinese patients was further confirmed in an additional tumor set (10/54=18.5%). Notably, two novel gene fusions, CTAGE5-KHDRBS3 (20/54=37%) and USP9Y-TTTY15 (19/54=35.2%), occurred frequently in our patient cohort. Further systematic transcriptional profiling identified numerous long ncRNAs that were differentially expressed in the tumors. An analysis of the correlation between expression of long ncRNA and genes suggested that long ncRNAs may have functions beyond transcriptional regulation. This study yielded new insights into the pathogenesis of prostate cancer in the Chinese population.Cell Research advance online publication 21 February 2012; doi:10.1038/cr.2012.30.