Transcription profiling of human KNS42 cells treated with the dual pI3-kinas/mTOR inhibitor PI-103
ABSTRACT: Sensitivity to temozolomide (TMZ) is restricted to a subset of glioblastoma patients, with the major determinant of resistance a lack of promoter methylation of the gene encoding the DNA methyltransferase MGMT, although other mechanisms are thought to be active. In a genome-wide screen of paediatric and adult glioma cells, we identified a co-ordinated upregulation of HOX gene expression in the MGMT-independent cell line KNS42. As a recent study has proposed a mechanism for this observation whereby transcriptional activation of the HOXA cluster is reversible by a PI3-kinase inhibitor through an epigenetic mechanism involving histone H3K27 trimethylation, we sought to investigate whether this was active in our system. We thus treated KNS42 cells for 24 hours with the dual PI3-kinase / mTOR inhibitor PI-103 at 5x IC50 and carried out gene expression profiling using Illumina HT-12 microarrays.
Sensitivity to temozolomide is restricted to a subset of glioblastoma patients, with the major determinant of resistance being a lack of promoter methylation of the gene encoding the repair protein DNA methyltransferase MGMT, although other mechanisms are thought to be active. There are, however, limited preclinical data in model systems derived from pediatric glioma patients. We screened a series of cell lines for temozolomide efficacy in vitro, and investigated the differential mechanisms of r ...[more]
Project description:We have previously determined the insulin-like growth factor 1 receptor (IGF1R) to be amplified and overexpressed in paediatric glioblastoma. In order to probe the efficacy and mechanisms of action of various inhibitors of the receptor, we have carried out expression profiling of paediatric glioblastoma cells treated with 5x IC50 of the compounds PPP and NVP-AEW541 over a 24 hour time-course.
Project description:Constitutive signalling pathway activation is a key feature of primary tumours and cancer cell lines. The regulation of gene expression changes may be via both genomic and epigenetic means, and understanding the mechanisms by which signal transduction may be activated can provide rational targets for therapeutic intervention. We have previously carried out DNA copy and expression profiling on a unique panel of five paediatric glioma cell lines, and have noted only a limited influence of gene amplification on gene expression. In the present study we have extended our work to include a measure of global methylation changes as well as micro RNA profiling in the same cell lines. We noted various instances of signalling pathway activation associated with specific hypermethylation or miRNA regulation of gene expression at various effectors also observed in primary paediatric tumours. These data provide evidence for the multifaceted nature of gene expression changes in paediatric high grade glioma, and identify novel targets for targeted therapy in this treatment refractory disease.
Project description:We have previously determined the insulin-like growth factor 1 receptor (IGF1R) to be amplified and overexpressed in Wilms tumour. In order to probe the efficacy and mechanisms of action of various inhibitors of the receptor, we have carried out expression profiling of Wilms tumour cells treated with 5x IC50 of the compounds PPP and NVP-AEW541 over a 24 hour time-course.
Project description:To gain insights into the transcriptional differences between subgroups of grade III invasive ductal breast cancers, we performed gene expression profiling of a series of RNA extracted from microdissected frozen tissue from patients with breast cancer
Project description:To gain insights into the genetic program activated within the distinct vascular and inflammatory transplant microenvironments in Id1/Id3 deficient and WT mice, we performed a series of gene screening experiments using RNA from total graft tissue as well as from myeloid and endothelial (i.e., CD31+ and ISB4+) cells isolated from the grafts at 1 week post-transplantation.
Project description:Gene expression profiles were generated with Illumina arrays for untreated human mesenchymal stem cells and also Argonaute1 bound mRNAs in the same cells. In addition gene expression profiles were generated for the human embryo cell line H1 before and after differentiation along the neural lineage. NOTE: assays for human embryonic stem cells before and after differentiation were added in July 2014 and data files for the mesenchymal stem cells were updated.
Project description:We found a candidate region (with 55 known or predicted genes) that was found to linkage to the MACS syndrome. Because it is transmitted in an autosomal recessive fashion, and given the fact most recessive disorders are caused by loss-of-function mutations often resulting in decreased mRNA levels, we hypothesized that screening the expression of the various genes located within the disease interval may point to candidate genes of interest. We therefore established fibroblast cell lines from punch skin biopsies obtained from 2 patients and 4 ethnically matched healthy controls. We then compared global gene expression using microarrays in the 6 cell lines (all genes contained within the disease interval were represented on the array).