Project description:Genome-wide association studies have identified a locus within the second intron of the FGFR2 gene that is consistently the most strongly associated with estrogen receptor-poisive breast cancer risk. However, we know little about the mechanisms by which the FGFR2 locus mediates risk or the pathways in which multiple risk loci may combine to cause disease. Previously, a systems biology approach was adopted to elucidate the regulatory networks operating in MCF-7 breast cancer cells in order to examine the role of FGFR2 in mediating risk. Here, the same approach has been employed using MCF-7 cells that have been treated with siRNA directed against FGFR2, in order to knock-down FGFR2 expression, to confirm that the differential gene expression that we see when FGF10 signalling is perturbed, on a background of estrogen signalling, is mediated via FGFR2 stimulation.
Project description:To study the effect of FOXA1 knock-down on DNA methylation patterns, we performed DNA methylation profiling of MCF-7 cells in three conditions, (1) control cell line, (2) cell line subjected to siRNA-mediated knockdown of endogenous FOXA1 expression and (3) cell line whose endogenous FOXA1 knockdown is rescued with transient expression of FOXA1-V5.
Project description:By survival analysis of breast cancer patients, JMJD6 was found to be significantly associated with poor prognosis. Over-expression and knock-down of JMJD6 in breast cancer cell lines suggested a role in proliferation. In order to study the transcriptional events that occur following JMJD6 expression changes, siRNA-mediated knock-down of JMJD6 was performed in MCF-7 and MDA-MB231 and stable over-expression of JMJD6 was performed in MCF-7.
Project description:By survival analysis of breast cancer patients, JMJD6 was found to be significantly associated with poor prognosis. Over-expression and knock-down of JMJD6 in breast cancer cell lines suggested a role in proliferation. In order to study the transcriptional events that occur following JMJD6 expression changes, siRNA-mediated knock-down of JMJD6 was performed in MCF-7 and MDA-MB231 and stable over-expression of JMJD6 was performed in MCF-7. There are 2 different siRNA-mediated knock-downs of JMJD6 with 2 biological replicates in MCF-7 and MDA-MB231; 3 clones of JMJD6 over-expression with 3 biological replicates in MCF-7. The control for the knock-downs is scrambled siRNA-treated MCF-7 and MDA-MB231 and the control for JMJD6 over-expression is empty vector over-expression in MCF-7.
Project description:Fibroblast Growth Factor (FGF) dependent signalling is frequently activated in cancer by a variety of different mechanisms. However, the downstream signal transduction pathways involved are poorly characterised. Here a quantitative differential phosphoproteomics approach, SILAC, is applied to identify FGF-regulated phosphorylation events in two triple- negative breast tumour cell lines, MFM223 and SUM52PE, that exhibit amplified expression of FGF receptor 2 (FGFR2) and are dependent on continued FGFR2 signalling for cell viability. Comparative Gene Ontology proteome analysis revealed that SUM52PE cells were enriched in proteins associated with cell metabolism and MFM223 cells enriched in proteins associated with cell adhesion and migration. FGFR2 inhibition by SU5402 impacts a significant fraction of the observed phosphoproteome of these cells. This study expands the known landscape of FGF signalling and identifies many new targets for functional investigation. FGF signalling pathways are found to be flexible in architecture as both shared, and divergent, responses to inhibition of FGFR2 kinase activity in the canonical RAF/MAPK/ERK/RSK and PI3K/AKT/PDK/mTOR/S6K pathways are identified. Inhibition of phosphorylation-dependent negative-feedback pathways is observed, defining mechanisms of intrinsic resistance to FGFR2 inhibition. These findings have implications for the therapeutic application of FGFR inhibitors as they identify both common and divergent responses in cells harbouring the same genetic lesion and pathways of drug resistance.