Project description:Prostate cancer is the second most occurring cancer in men worldwide, and with the advances made with screening for prostate-specific antigen, it has been prone to early diagnosis and over-treatment. To better understand the mechanisms of tumorigenesis and possible treatment responses, we developed a mathematical model of prostate cancer which considers the major signalling pathways known to be deregulated. The model includes pathways such as androgen receptor, MAPK, Wnt, NFkB, PI3K/AKT, MAPK, mTOR, SHH, the cell cycle, the epithelial-mesenchymal transition (EMT), apoptosis and DNA damage pathways. The final model accounts for 133 nodes and 449 edges. We applied a methodology to personalise this Boolean model to molecular data to reflect the heterogeneity and specific response to perturbations of cancer patients, using TCGA and GDSC datasets.
Project description:MicroRNAs are a class of small non-coding RNAs that control gene expression by targeting messenger RNAs and triggering either translation repression or RNA degradation. Their aberrant expression may be involved in human diseases, including cancer. Indeed, microRNA aberrant expression has been previously found in human chronic lymphocytic leukemias, where microRNA signatures were associated with specific clinico-biological features. Here, we show that, in comparison to normal breast tissue, microRNAs are also aberrantly expressed in human breast cancer. The overall microRNA expression could clearly separate normal versus cancer tissues, with the most significantly deregulated microRNAs being mir-125b, mir-145, mir-21, mir-155. Results were confirmed by microarray and Northern blot analyses. We could identify microRNAs whose expression was correlated with specific breast cancer bio-pathologic features, such as estrogen and progesterone receptor expression, tumor stage, vascular invasion or proliferation index.
Project description:Deregulated expression of ETS transcription factors with oncogenic and tumor suppressor function occurs frequently in prostate cancer leading to profound alterations of the cancer transcriptome. By integrating genomic and functional studies we identified key targets of the aberrantly expressed ETS factors, ERG and ESE3. Altered expression of ETS factors led to the induction of the polycomb group protein EZH2 and silencing of the tumor suppressor Nkx3.1. Nkx3.1 was controlled by ERG and ESE3 both directly via binding to ETS binding sites in the gene promoter and indirectly via EZH2-induced histone H3K27 methylation. This may represent a general mechanism linking aberrantly expressed ETS with deregulation of epigenetic pathways and global reprogramming of the prostate epithelial cell transcriptome in prostate tumorigenesis. Keywords: prostate cancer, gene expression profiling, ETS genes In this study we show that deregulated expression of ETS factors with opposite functions is highly frequent in prostate cancer. Our study uncovers a previously unrecognized link between aberrant expression of ETS factors, deregulation of epigenetic pathways and silencing of tumor suppressor genes in prostate cancer and shows that partially distinct transcriptional programs are associated with different ETS gene expression patterns. The presence of distinct prostate cancer subgroups with different biological features may have important clinical implications and suggests that assessment of ETS expression levels might be useful to distinguish tumors with different clinical outcome.
Project description:Deregulated expression of ETS transcription factors with oncogenic and tumor suppressor function occurs frequently in prostate cancer leading to profound alterations of the cancer transcriptome. By integrating genomic and functional studies we identified key targets of the aberrantly expressed ETS factors, ERG and ESE3. Altered expression of ETS factors led to the induction of the polycomb group protein EZH2 and silencing of the tumor suppressor Nkx3.1. Nkx3.1 was controlled by ERG and ESE3 both directly via binding to ETS binding sites in the gene promoter and indirectly via EZH2-induced histone H3K27 methylation. This may represent a general mechanism linking aberrantly expressed ETS with deregulation of epigenetic pathways and global reprogramming of the prostate epithelial cell transcriptome in prostate tumorigenesis. Keywords: prostate cancer, gene expression profiling, ETS genes