Project description:Basal-like breast cancer is a heterogeneous disease characterised by the expression of basal cell markers, no oestrogen or progesterone receptor expression and a lack of HER2 overexpression. Recent studies have linked activation of the Wnt/beta-catenin pathway to basal-like breast cancer. Transgenic mice expressing N-terminally truncated stabilised beta-catenin in the mammary basal/myoepithelial cell layer (K5deltaNbetacat strain) develop mammary hyperplasias that progress to invasive carcinomas. Histological and microarray analyses of these lesions have revealed their high similarity to a subset of basal-like human breast tumours with squamous differentiation. As in human basal-like carcinomas, the Myc pathway was found to be activated in the mammary lesions of K5deltaNbetacat mice. Mammosphere and transplantation assays showed that a basal cell population with stem/progenitor characteristics was amplified in K5deltaNbetacat mouse preneoplastic glands. Myc deletion from the mammary basal layer of K5deltaNbetacat mice abolished both basal cell regenerative capacity and tumorigenesis. These results show that Myc is essential for beta-catenin-induced stem cell amplification and tumorigenesis and that basal stem/progenitor cells may be at the origin of a subset of basal-like breast tumours. mammary tissue from K5M-NM-^TNM-NM-2cat mice were dissected at successive stages of development (small hyperplasia (n=5), large hyperplasia (n=5), tumor (n=11) and control (n=4)) for RNA extraction and hybridization on Affymetrix microarrays
Project description:Total RNA from trichomes of fifth and sixth rosette leaves of three-week-old wild-type and gtl1-1 mutants (Figure 3B) were extracted. We found a total number of 1,759 genes, corresponding to 1,694 probes on the ATH1 chip, that show differential expression of at least 1.3-fold. Out of these 1,694 genes, 47.2% are positively regulated and 52.8% are negatively regulated by GTL1. Compared gene expressions in fifth and sixth rosette leaves of three-week-old wild-type and gtl1-1 mutants
Project description:Purpose: To determine the 8-week disease control rate (DCR) of sorafenib monotherapy in patients with advanced non-small-cell lung cancer (NSCLC) in the BATTLE trial. Methods: Patients with pre-treated NSCLC consented to baseline biopsies for pre-specified biomarkers assessment and biomarker discovery. Sorafenib was given at 400 mg orally twice daily until tumor progression or unacceptable toxicity. Outcomes by pre-specified biomarkers were analyzed and a Sorafenib sensitivity signature developed using high-throughput gene expression profiles of NSCLC cell lines and baseline biopsies. Results: 105 patients were eligible and 98 patients were evaluable. Median age was 62 (range 34-81) years, 51% of patients were male, 75% were former/current smokers, and 89% had an ECOG performance status of 0-1. Median prior chemotherapies for stage IV NSCLC were two. Median follow-up was 9.4 (range: 1.3-32.2) months. Overall, 8-week DCR was 58.2%. Patients with EGFR mutations had significantly lower 8-week DCR compared to patients with wild-type tumors (23.1% vs. 64.2%, P=0.0119), and patients with K-RAS mutations had the highest 8-week DCR (67%). Most commonly reported treatment-related adverse events include hand-foot syndrome (59.6%), fatigue (42.3%), rash (40.4%), diarrhea (38.5%), and weight loss (38.5%). Sorafenib sensitivity signature developed in cell lines was associated with an improved outcome. Conclusion: Patients with wild-type EGFR, including those with K-RAS mutation, may benefit from sorafenib as opposed to patients with EGFR mutation. We identify a gene expression signature associated with an improved outcome in patients with wild-type EGFR treated with sorafenib. BATTLE-2 trial is ongoing to validate those results. ClinicalTrials.gov number, NCT00411671. Gene expression profiles were measured in 37 core biopsies from patients with refractory non-small cell lung cancer treated with sorafenib in the Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) trial. We report a Sorafenib sensitivity gene expression signature trained in vitro (separate GEO submission), and tested in baseline biopsies collected in the BATTLE trial.
Project description:We have shown previously that older flies are intrinsically more susceptible to Aβ42 toxicity. Building upon these findings, this study aimed to determine the mechanisms by which ageing increases this vulnerability to damage in the brain. A fixed dose of Aβ42 peptide was induced in young (5d) versus older (20d) fly neurons, and then gene and protein expression changes examined in dissected fly brains using microarray analyses. This unbiased approach has revealed genes and pathways that correlate with increased susceptibility of the ageing brain to proteotoxicity.
Project description:Originally linked with development and differentiation, the role of microRNAs (miRNAs) in many important biological processes has emerged and dysregulation of miRNA expression has been connected with cancer pathogenesis. The association between abnormal expression levels of miRNAs and colon cancer has been mainly demonstrated in primary tumors; more recently, non-overlapping sets of oncomirs, tumour suppressor miRNAs and metastamirs have been associated with distinct stages of colo-rectal cancer (CRC) progression. In an attempt to identify changes in both miRNA and gene expression levels along the colon mucosa - primary tumor - liver metastasis- sequence and to classify miRNAs into distinct functional networks according to the expression of their anti-correlated and differentially expressed target genes, we analyzed a large set of sample-matched miRNA and mRNA expression profiles, including the complete non tumor tissue, primary carcinoma and liver metastasis sequence from 8 patients. Our study shows that the largest changes in miRNA and gene expression levels occur in normal mucosa to tumor transition and are almost stably maintained in the subsequent tumor to metastasis transition. Only a few miRNAs were differentially expressed between liver metastasis and primary carcinoma; however, miRNA expression profiles classified better primary tumors and metastases compared to mRNA profiles. By integration of miRNAs and target genes expression data, we were able to infer regulatory networks modulated by miRNAs during colorectal tumorigenesis and metastatic process, and associate them to the affected biological pathways. In particular, we identified a combination of interconnected miRNAs, up- or down-regulated during tumorigenesis, which are organized into distinct sub-networks, each of which includes several regulatory relationships with differentially expressed genes. Among them, the relationship between miR-182, up-regulated in colon cancer, and the anti-correlated ENTPD5 gene was identified for the first time and confirmed in an independent set of samples. We determined miRNA expression profile for 78 samples comprising 23 normal adjacent mucosa (N), 31 primitive colorectal cancer (T) and 24 liver metastases (M), obtained from 45 patients who underwent surgery at University of Padova (Surgery Branch, Department of Oncological and Surgical Sciences) between March 1994 and September 2008. This dataset included 24 samples belonging to 8 patients with matched samples (N, T and M) from the same patients. We also examined the expression profiles for 80 samples, comprising 23 N, 30 T, 27 M, and including 27 per-patient matched samples from 9 patients. Considering both miRNAs and genes expression experiments, we obtained a set of 77 samples (23N, 30T, 24M) with matched miRNAs and genes expression data from the same biological sample, to reconstruct post-transcriptional regulatory networks.
Project description:The aim of this study was to develop human bronchial and nasal epithelium culture models that are relevant to investigate the impact of cigarette smoke (CS) observed in vivo in respiratory tract tissues in contact with inhaled CS. We used two organotypic cultures generated from primary cells derived from non-smoking donors that contain fibroblasts and epithelial cells in order to reproduce as closely as possible the in vivo situation. To mimic the smoking behavior of a moderate smoker during one day, human tissue cultures (bronchial and nasal epithelium) were exposed repeatedly and directly at the air/liquid interface (using the Vitrocell(R) System) to two doses (high 4.2 ug TPM/cm2 and low 2.2 ug TPM/cm2 per cigarette) of the whole smoke generated by one cigarette or to humidified air (sham). CS exposure was repeated four times with one hour intervals between each cigarette. Various endpoints (e.g., gene and microRNA expression, CYP activity, pro-inflammatory markers release, differential cell counts, cytotoxicity measurement) were then captured to assess the baseline (time 0) and early responses of the tissues after exposure (4 hours) as well as the recovery phase (24 and 48 hours).
Project description:Gene expression profiles among avascular region (around ventricular zone), highly vascularized region with honeycomb-patterned vascular plexus (around subventricular zone and intermediate zone), and cortical plate with vertically oriented vessels from laser-captured microdissected E14.5 neocortex were compared by microarray
Project description:As part of a study of the role of the aryl hydrocarbon receptor (Ahr) in maintenance and senescence of hematopoietic stem cells (HSC), global gene expression profiling was done with HSC isolated from Ahr-knockout and wild-type mice. HSC from young-adult (8 wk old) AhR-KO mice had changes in expression of many genes related to HSC maintenance, consistent with the phenotype observed in aging Ahr-KO mice: decreased survival rate, splenomegaly, increased circulating white blood cells, hematopoietic cell accumulation in tissues, anemia, increased numbers of stem/progenitor and lineage-committed cells in bone marrow, decreased erythroid progenitor cells in bone marrow, and decreased self-renewal capacity of HSC. 7 samples: 3 Ahr knockout, 4 wild-type
Project description:As part of a study of the role of the aryl hydrocarbon receptor (Ahr) in maintenance and senescence of hematopoietic stem cells (HSC), global gene expression profiling was done with HSC isolated from 18-month-old Ahr-knockout and wild-type mice. HSC from aged AhR-KO mice had changes in expression of many genes related to HSC maintenance, consistent with the phenotype observed in aging Ahr-KO mice: decreased survival rate, splenomegaly, increased circulating white blood cells, hematopoietic cell accumulation in tissues, anemia, increased numbers of stem/progenitor and lineage-committed cells in bone marrow, decreased erythroid progenitor cells in bone marrow, and decreased self-renewal capacity of HSC. 10 samples: 5 Ahr knockout, 5 wild-type