Cells are constantly exposed to stress. Most of those stresses do not necessarily cause cell death or visible damage. The present study explores the way the immune system responds to such sub lethal stressed cells.
Cells exposed to sublethal oxidative stress selectively attract monocytes/macrophages via scavenger receptors and MyD88-mediated signaling.
Specimen part, Treatment
View SamplesApproximately 5% of all breast cancers can be attributed to an inherited mutation in one of two cancer susceptibility genes, BRCA1 and BRCA2. We searched for genes that have the potential to distinguish healthy BRCA1 and BRCA2 mutation carriers from non-carriers based on differences in expression profiling. Using expression microarrays we compared gene expression of irradiated lymphocytes from BRCA1 and BRCA2 mutation carriers versus control non-carriers. We identified 137 probe sets in BRCA1 carriers and 1345 in BRCA2 carriers with differential gene expression. Gene Ontology analysis revealed that most of these genes relate to regulation pathways of DNA repair processes, cell cycle regulation and apoptosis. Real-time PCR was performed on the 36 genes which were most prominently differentially expressed in the microarray assay; 21 genes were shown to be significantly differentially expressed in BRCA1 or BRCA2 mutation carriers as compared to controls (p<0.05). Based on a validation study with 40 mutation carriers and 17 non-carriers, a multiplex model that included six or more coincidental genes of 18 selected genes was constructed in order to predict the risk of carrying a mutation. The results using this model showed sensitivity 95% and specificity 88%. In summary, our study provides insight into the biological effect of heterozygous mutations in BRCA1 and BRCA2 genes in response to ionizing irradiation induced DNA damage. We also suggest a set of 18 genes that can be used as a prediction and screening tool for BRCA1 or BRCA2 mutational carriers by using easily obtained lymphocytes.
Determination of molecular markers for BRCA1 and BRCA2 heterozygosity using gene expression profiling.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Sex, Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Specific genomic and transcriptomic aberrations in tumors induced by partial hepatectomy of a chronically inflamed murine liver.
Sex, Specimen part, Treatment
View SamplesSurgical resection is the preferred treatment for Hepatocellular carcinoma; however, it induces tumor recurrence. Our objective was to understand the molecular mechanisms linking liver regeneration under chronic-inflammation to tumorigenesis. Mdr2-knockout mice, a model of inflammation-associated cancer, underwent partial-hepatectomy which led to enhanced hepatocarcinogenesis. Yet, liver regeneration in these mice was severely attenuated. We demonstrate the activation of the DNA damage response machinery and altered genomic instability during early liver inflammatory stages resulting in hepatocyte apoptosis and cell-cycle arrest, and suggest their involvement in tumor recurrence subsequent to partial hepatectomy. We propose that under the regenerative proliferative stress induced by liver resection, the genomic unstable hepatocytes generated during chronic-inflammation, escape apoptosis and reenter the cell-cycle, triggering the enhanced tumorigenesis
Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.
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View SamplesChronic inflammation is a common underlying condition associated with tumor development, accounting for approximately 20% of human cancers. This association is especially apparent in Hepatocellular carcinoma (HCC), which often develops on the background of chronic hepatitis and hepatic fibrosis, slowly unfolding on a background of chronic inflammation. HCC is one of the most common tumors worldwide, exhibiting a very poor prognosis and high mortality rate with limited available therapeutic tools. The etiology of liver cancer is well known, however there is still a lack of precise knowledge about pathogenesis of HCC. IL-6 have been shown to be of importance for liver protection and prevention of liver injury in animal models of acute sclerosing cholangitis and correlate with increased HCC in human patients. Using a murine model of chronic cholangitis based on the ablation of the Mdr2 gene, this study has examined the role of IL-6 signaling in chronic hepatitis and in the subsequent development of liver cancer. The main observations of this study are that IL-6 signaling in female Mdr2-KO mice protects from the development of liver injury and fibrosis, but simultaneously rduced tumor initiation.
No associated publication
Sex, Age
View SamplesFetal mice (16 days gestation) were administered feline immunodeficiency virus (FIV)-based lentiviral viral particles containing the gene encoding GFP. Six liver tumors developed in three mice between the ages of 273 and 484 days, each mouse developed 2 tumors. These tumors and non-tumorous liver tissue from the same animals and animals that did not develop tumors and untransduced controls were harvested and microarrays were performed on total RNA extracted from these samples. We were interested in investigating the link between lentiviral integration and gene expression.
Transduction of fetal mice with a feline lentiviral vector induces liver tumors which exhibit an E2F activation signature.
Sex, Age, Specimen part
View SamplesThe liver is a multifunctional organ, which undergoes rapid changes during the developmental period and relies on tightly-regulated gene expression. Little is known regarding the complex expression patterns of mRNAs during the early stages of human liver development in comparison to post-natal livers.
Comprehensive gene and microRNA expression profiling reveals a role for microRNAs in human liver development.
Specimen part
View SamplesWnt signaling, which drives the rapid self-renewal of the gut epithelium is causally associated with intestinal neoplasia. Here we show that CKIalpha is a activation depends on p53 and p21Waf1/Cip1: CKI ablation provokes activation of p53 and p21, which assume a pivotal role in suppressing invasive cancer. Dual loss of CKIalpha and either p53 or p21 results in rapid, rampant malignant signature denoted p53supinv (p53-suppressed invasiveness) that is conditionally induction of invasiveness. Like invasiveness control, the transcriptional suppression of p53supinv genes is largely mediated by p21, independently of cell cycle control, representing a novel tumor suppressor function of wild-type p53.
No associated publication
Specimen part
View SamplesBackground & Aims. Resection of hepatocellular carcinoma (HCC) tumors by partial hepatectomy (PHx) is associated with promoting hepatocarcinogenesis. We have previously reported that PHx promotes hepatocarcinogenesis in the Mdr2-knockout (Mdr2-KO) mouse, a model for inflammation-mediated HCC. Now, we explored the molecular mechanisms underlying the tumor-promoting effect of PHx in these mice. Methods. Using microarrays-based techniques, we compared genomic and transcriptomic profiles of HCC tumors developing in the Mdr2-KO mice either spontaneously or following PHx. Results. PHx accelerated HCC development in these mice by four months. PHx-induced tumors had only amplifications affecting multiple chromosomes and locating mainly near the acrocentric centromeres of murine chromosomes. Four different chromosomal regions were amplified each in at least three tumors. All tumors of untreated mice had chromosomal aberrations, including both deletions and amplifications. Comparison of gene expression profiles revealed a significantly enriched expression of oncogenes, chromosomal instability markers and E2F1 targets in the post-PHx compared to spontaneous tumors. Both tumor groups shared the same frequent amplification at chromosome 18. Here, we demonstrated that one of the regulatory genes encoded by this amplified region, Crem, was over-expressed in the nuclei of murine and human HCC cells in vivo, and that it stimulated proliferation of human HCC cells in vitro. Conclusions: PHx of a chronically inflamed liver directed tumor development to a discrete pathway characterized by amplification of specific chromosomal regions and expression of specific tumor-promoting genes. Crem is a new candidate HCC oncogene frequently amplified in this model and frequently over-expressed in human HCC.
Specific genomic and transcriptomic aberrations in tumors induced by partial hepatectomy of a chronically inflamed murine liver.
Specimen part, Treatment
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