ABSTRACT: Increased expression of GLI1 is associated with poor prognosis for some breast cancer subtypes. A conditional transgenic GLI1 expressing mouse model, with or without heterozygous deletion of Trp53, was used to generate and study GLI1 induced mammary gland tumours. Tumour tissue was serially orthotopically transplanted for at least 10 generations in NSG mice.
Project description:To identify early events of erbB2-induced mammary tumorigenesis, we compared datasets from 14 genechip experiments including MMTV-neu tumors, preneoplastic neu mammary gland (adjacent neu), and age-matched, wild-type control mammary glands
Project description:The aim of the experiment was to analyse gene expression profiles in Brca1 tumours arising from different mammary epithelial cell populations use a Cre-loxP based conditional knockout system. K14 promoter driving Cre expression caused Brca1 knockout in basal stem cells and thus stem cell origin tumours whereas Blg promoter driving Cre expression caused Brca1 knockout in luminal progenitor cells and thus progenitor origin tumours. Individual arrays were carried out on labelled cDNA made from RNA isolated from mouse mammary tumours. Only cDNA passing Almac diagnostics QC criteria were hybridised to arrays. Only arrays passing QC criteria after hybrisiation were subsequently analysed.
Project description:SWATH-MS enables accurate and reproducible label-free quantification of proteomes including in extensively studied model organisms such as the mouse. Here we present a comprehensive mouse reference spectral library (MouseRefSWATH) that allows quantification of up to 10,597 proteins (62.2% of mouse proteome) by SWATH-MS. We exploit MouseRefSWATH to develop an analytical pipeline for species-specific deconvolution of proteomic alterations in human tumour xenografts (XenoSWATH). This method overcomes the challenge of high protein sequence similarity between the mouse and human, facilitating the study of host microenvironment-tumour interactions from ‘bulk tumour’ measurements. We apply XenoSWATH to characterise a xenograft model of breast ductal carcinoma in-situ and uncover complex regulation of cell migration pathways that is not restricted to the tumour cells but also operates in the mouse stromal upon progression to invasive disease. MouseRefSWATH and XenoSWATH opens new possibilities for in-depth proteomic assessment to address wide-ranging biological questions involving this important model organism.
Project description:Sonic hedgehog (Shh) signals via Gli transcription factors to stimulate proliferation of granule neuron precursor cells (GNPs) in the cerebellum. Deregulation of Shh target genes often results in unrestrained GNP proliferation and eventually medulloblastoma (MB), the most common pediatric brain malignancy. Gene expression profiling was coupled with transcription factor binding location analysis to determine the Gli1-controlled transcriptional regulatory networks in GNPs and medulloblastoma cells. We detected significant overlap, as well as differences, in the Gli1-controlled transcriptional regulatory networks in GNPs and MBs. We determined the presence of gene expression in each dataset. There were 9260 genes expressed in Gli1-FLAG GNPs and 9185 genes expressed in Gli1-FLAG;Ptc+/- tumors; 8691 of which are in common. The large overlap is consistent with the cellular origin of these tumors. When the genes detectably expressed were intersected with our binding data, there were only 132 putative Gli1 target genes shared by both cell populations. Due to the heightened activation of the Hh pathway in tumors relative to GNPs, we further deduced direct Gli1 target genes exclusive to tumors by determining significantly induced genes in tumors versus in Ptc+/- GNPs. We identified at least 116 tumor-specific Gli1 target genes. These data suggest that tumor formation is accompanied by a tremendous change in the battery of Gli target genes. Presence of gene expression was determined for all samples: Gli1-FLAG-expressing GNPs, Ptc+/- GNPs, and Gli1-FLAG;Ptc+/-medulloblastomas. These datasets were intersected with chIP-chip data to determine potential direct Gli1 target genes. Differential gene expression was determined by comparing expression profiles from medulloblastoma tumors to those from Ptc+/- GNPs.
Project description:ErbB-2 overexpression and amplification occurs in 15 - 30% of human invasive breast carcinomas associated with poor clinical prognosis. Previously, we have demonstrated that four ErbB-2/Neu tyrosine-autophosphorylation sites within the cytoplasmic tail of the receptor recruit distinct adaptor proteins and are sufficient to mediate transforming signals in vitro. Two of these sites representing the Grb2 (Neu-YB) and Shc (Neu-YD) binding sites can induce mammary tumourigenesis and metastasis. Here we show that Neu-YC and Neu-YE transgenic mice develop metastatic mammary tumours. A detailed comparison of pathological and transcriptional profiles among all Neu mutant mouse models revealed that Neu-YC, -YD and -YE mammary tumours shared similar pathological and transcriptional features correlating with their capacity to signal through a common adaptor like Shc. In contrast, the Neu-YB mouse model displayed a unique pathology with a high metastatic potential that correlates with a distinct transcriptional profile. We identified genes specifically expressed in YB-induced mammary tumours, including CXCL12/SDF-1α that promotes malignant tumour progression. Furthermore, Neu-YB tumour epithelial cells showed abundant intracellular CXCL12/SDF-1α protein, which may reflect the more aggressive phenotype among all Neu mutant mouse models. These findings indicate that activation of distinct Neu-coupled signalling pathways has a deep impact on the biological behaviour of Neu-induced tumours. Experiment Overall Design: Total RNA was isolated from 10 individual flash frozen mammary tumour samples derived from our MMTV/neundl-NYPD, -YB, -YC, -YD, -YE and the parental MMTV/neu NDL2-5 strains. Two RNA pools, containing equal amount of total RNA from five individual tumours, were generated from each strain and functioned as a biological repeat. Five hundred nanograms of total RNA from each pool was subjected to one round of T7 linear amplification using the Amino Allyl MessageAmpTM aRNA Kit (Ambion, Austin, Texas). Ten micrograms of the resulting aRNA was labelled with Cy3 and Cy5 dyes. Each of the 12 Samples represents a dyeswap pair.
Project description:Sonic hedgehog (Shh) signals via Gli transcription factors to promote maintenance and proliferation of neural stem cells in the adult mouse forebrain. We have analyzed the gene expression pattern in neurogenic Shh-responding astroglia (= neural stem cells ) in the subventicular zone of the lateral ventricle and dentate gyrus of the hippocampus in comparison to the non-neurogenic Shh-responding glia (=Bergman glia) in the cerebellum to identify the genes specifically involved in neurogenic function downstream of Shh signaling. In this dataset, we include the expression data obtained from FACS-sorted Gli1+ GFAP+ cells from microdissected SVZ, hippocampus and cerebellum. GFAP expression is based on hGFAP-GFP reporter line and Gli1 expression is lineage marked using Gli1-CreER;ROSA26-tdTomato mice. 15 Total samples were analyzed. We compared expression levels of SVZ vs. Cerebellum, Hippocampus vs. Cerebelllum to identify genes which had more than 4 fold change in expression levels with p < 0.01. From this narrowed list, we compared between SVZ and Hippocampus to identify the common genes up and down regulated. In addition, we also identified commonly expressed genes in hippocampus and SVZ at high level.
Project description:Tomato-traced single cells from the interfollicular epidermis including the touch dome (Gli1-Tomato+/Sca1+) and the hair follicle (Gli1-Tomato+/Sca1-) were FACS-sorted, randomly sequenced and clustered into epidermal (sub-)populations.
Project description:We propose a new pipeline for the refinement of spectrum-peptide assignment, designed specifically for MHC ligand identification. By modeling the peptidome as a collection of a limited number of specificities, corresponding to the MHC alleles of the cell line, our method achieves increased sequencing depth, while at the same time removing potential experimental outliers and contaminants.