Transcription profiling by array of xenografted tumors derived from human ovarian cell line model A2780 and its cisplatin resistant variant A2780cis
ABSTRACT: Molecular mechanisms underlying the development of resistance to platinum treatment in patients with ovarian cancer remain poorly understood. This is mainly due to the lack of appropriate in vivo models allowing identification of factors that are regulated during initial treatment and of acquired resistance-related genes. In this study, we used whole genome microarrays and linear model analysis to identify potential resistance-related genes by comparing the expression profiles of the parental human ovarian cancer model A2780 and its cisplatin-resistant variant A2780cis, before and after carboplatin treatment in vivo.
Project description:Although amyloid-beta42 (Abeta42) has long been implicated in the pathogenesis of Alzheimer disease (AD), the biological basis of its effects remains uncertain. Intraneuronal Abeta accumulation in brains of patients with AD or Down syndrome, in animal models, and in cultured cells has suggested an early pathophysiological role specific for intracellular Abeta40 and Abeta42. As a consequence of intraneuronal oligomerization, cell death can result from ER stress, endosomal/lysosomal leakage, and mitochondrial dysfunction. A possible nuclear role of intraneuronal Abeta has remained unexplored so far. We here study the role of intranuclear Abeta40 versus Abeta42 and Abeta42_G33A, and an untreated vehicle control in synchronized SH-SY5Y cells. RNA samples for microarray gene expression profiling were collected at t=0, 2, 6, 8 and 12 hours after incubation with Abeta40, Abeta42 and Abeta42_G33A peptides, respectively.'
Project description:Human uterine fibroids are benign tumors derived from the smooth muscle layers of the uterus. Fibroid disease impacts up to 50% of premenopausal women in their daily life, and accounts for up to 50% of hysterectomies in the United States. Despite the health burden they impose, the development of these tumors is barely understood. To improve our understanding of this disease, we developed and characterized a patient-derived xenograft models by transplanting small pieces of human uterine fibroid tissue subcutaneously into immunodeficient mice. Growth of the fibroid grafts was dependent on 17beta-estradiol and progesterone supplementation and maintained for up to 60 days. A gene expression profiling study was performed in order to determine molecular characteristis of well-grown compared to not-grown uterine fibroid xenografts.
Project description:Background: Current protocols for the treatment of ovarian cancer include combination chemotherapy with a platinating agent and a taxane. However, many patients experience relapse of their cancer and the development of drug resistance is not uncommon, making successful second line therapy difficult to achieve. The objective of this study was to develop a cell line resistant to both carboplatin and docetaxel (dual drug resistant ovarian cell line A2780CBNDXL), along with single agent resistant lines (docetaxel resistant A2780DXL and carboplatin resistant A2780CBN), to investigate the mechanisms which underlie the development of dual drug resistance. Methods: The A2780 epithelial ovarian cancer cell line was used to select for isogenic carboplatin, docetaxel and dual drug resistant cell lines. A selection method of gradually increasing drug doses was implemented to avoid clonal selection. Resistance was confirmed using a clonogenic assay. Changes in gene expression associated with the development of drug resistance were determined by microarray analysis compared to parental co-culture control A2780CC. Changes in selected genes were validated by QPCR and immunoblotting. Results: Three isogenic cell lines were developed and resistance to each drug or the combination of drugs was confirmed. Development of resistance was accompanied by a reduced growth rate. The microarray and QPCR analyses showed that unique changes in gene expression occurred in the dual drug resistant cell line and that genes known to be involved in resistance could be identified in all cell lines. Conclusions: Novel changes in gene expression can occur in the development of dual drug resistance, indicating that dual drug resistance is not a simple combination of the changes occurring in single agent resistance Carboplatin, docetaxel (GSE26129) and carboplatin/docetaxel dual resistant cell lines of ovarian A2780 were generated for gene expression profilling. Two colour microarray of Agilent whole human genome nucleotide arrays was conducted with two replicate of both forward and reverse labellings for each cell line. Four arrays were used for this experiments. And it was four replicate of both forward and reverse labellings for A2780 cells. Eight arrays were used for this experiments
Project description:The patient-derived xenograft (PDX) model retains the heterogeneity of patient tumors, allowing a means to not only examine efficacy of a therapy across a population, but also study crucial aspects of cancer biology in response to treatment. Herein we describe the development and characterization of an ovarian-PDX model in order to study the development of chemoresistance. We demonstrate that PDX tumors are not simply composed of tumor-initiating cells, but recapitulate the original tumor’s heterogeneity, oncogene expression profiles, and clinical response to chemotherapy. Combined carboplatin/paclitaxel treatment of PDX tumors enriches the cancer stem cell populations, but persistent tumors are not entirely composed of these populations. RNA-Seq analysis of treated PDX tumors compared to untreated tumors demonstrates a consistently contrasting genetic profile after therapy, suggesting similar, but few, pathways are mediating chemoresistance. The pathways most significantly altered included Protein Kinase A signaling, GNRH signaling, and sphingosine-1-phosphate signaling. Pathways and genes identified by this methodology represent novel approaches to targeting the chemoresistant population in ovarian cancer 6 pairs of Patient-Derived Xenografts (PDX) were ananlyzed using RNA-seq for a total of 12 samples. Each pair consists of a treated and untreated PDX of ovarian cancer. Treated Ovarian cancer PDXs were treated with 4 weeks of a combination of carboplatin and taxol. RNA was isolated and converted to cDNA. RNA-seq was conductred on the Illumina HiSeq 2000 with 50 bp paired end sequencing
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. We carry out Chromatin immunoprecipitation (ChIP) prior to sequencing on Illumina Hiseq 2500 to report on the genome-wide H3K27me3 patterns in normal mouse liver, 12 week Phenobarbital exposed mouse livers and 35 week pehonbarbital exposed liver tumours.
Project description:A ""Cartes d'Identite des Tumeurs"" (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net). 73 samples (60 tumoral, 6 normal kidneys (NK), 3 fetal kidneys (FK) and 4 cell lines (L)), hybridized on Affymetrix HG-U133A GeneChips.Tumor classification based on a characterization of WT1 and Betacatenin. Identification of major differences between two categories of Wilms' Tumors defined according to WT1 and CTNNB1 genomic and expression features. First large scale study based on post-chemotherapy resected tumors, according to the SIOP protocoles.
Project description:Different cancer cell lines treated with the cell penetrating peptide APIM, alone and in combinatorial treatment with cytostatika. Low dose experiments over time, and higher dose over short time.
Project description:Serum-dependent transcriptional networks identify distinct functional roles for H-ras and N-ras during initial stages of the cell cycle; Using oligonucleotide microarrays, we compared gene expression transcriptional profiles corresponding to the initial cell cycle stages of mouse fibroblasts lacking H-Ras and/or NRas with those of matching, WT controls. The similarity of transcription profiles among serum-starved fibroblasts of all different WT and ras knockout genotypes tested, indicated that H-Ras and N-Ras do not play significant roles in control of transcriptional responses to serum deprivation stress. In contrast, genomic disruption of H-ras or N-ras, individually or in combination, determined highly specific, differential gene expression profiles in response to post-starvation stimulation with serum for 1 hour (G0/G1 transition) or for 8 hours (mid-G1 progression). The absence of N-Ras caused significantly higher changes than the absence of H-Ras on the wave of transcriptional activation linked to G0/G1 transition. In contrast, the absence of H-Ras affected more potently the profile of the transcriptional wave detected during mid-G1 progression. Functional analysis demonstrated a predominant functional association of H-Ras with growth and proliferation, whereas N-Ras exhibited a closer functional link to development or cell cycle regulation as well as immunomodulation and apoptosis. Mechanistic analysis indicated that ERK-dependent activation of Stat1 mediates the regulatory effect of N-Ras on defense and immunity, whereas the pro-apoptotic effects of N-Ras are mediated through ERK and p38 signaling. Our observations support previous reports of an absolute requirement for different peaks of Ras activity during the initial stages of the cell cycle and confirm the notion of functional specificity for the H-Ras and N-Ras isoforms. Experiment Overall Design: Mus musculus cell lines from the appropriate ras genotype were harvested on Dulbecco’s modified Eagle’s medium (DMEM) supplemented with fetal bovine serum (10% FBS), glutamine (2mM), penicillin (100 U/ml) and streptomycin (100 mg/ml). Cultures were grown in a humidified CO2 (5%) atmosphere at 37°C and when subconfluent cells were starved for 24 hours. After starvation cells were either used for RNA isolation, or induced for 1 hour or 8 hours with 20% fetal bovine serum and then RNA extraction and isolation was carried out for hybridization on Affymetrix microarrays.
Project description:A mouse model of asthma mimicking acute or chronic asthma disease was used to select genes undergoing a modulation in both acute and chronic conditions. Mice were exposed to ovalbumin during 1, 5 and 10 weeks (short, intermediate and long term model (ST, IT, LT)) and gene expression in the lung was studied using an Affymetrix 430 2.0 genome wide microarray compared to PBS exposed mice.