Background: Gq-coupled G protein-coupled receptors (GPCR) mediate the actions of a variety of messengers that are key regulators of cardiovascular function. Enhanced Gaq-mediated signaling plays an important role in cardiac hypertrophy and in the transition to heart failure. We have recently described that Gaq acts as an adaptor protein that facilitates PKCz-mediated activation of ERK5 in epithelial cells. Since the ERK5 cascade is known to be involved in cardiac hypertrophy, we have investigated the potential relevance of this pathway in Gq-dependent signaling in cardiac cells.
Protein kinase C (PKC)ζ-mediated Gαq stimulation of ERK5 protein pathway in cardiomyocytes and cardiac fibroblasts.
Sex, Age, Specimen part
View SamplesA permantly active form of the oncogene Akt was expressed in the keratinocytes of the basal proliferative layer of the epidermis. Stem cells of the hair follicle expressing the cell surface marker CD34 were isolated. RNA form the CD34(+) and CD34(-) keratinocytes was extracted and and hybridized to Mouse Genome 430 2.0 Affymetrix arrays.
Akt signaling leads to stem cell activation and promotes tumor development in epidermis.
Specimen part
View SamplesThe epidermal specific ablation of Trp53 gene leads to the spontaneous development of aggressive tumors in mice through a process that is accelerated by the simultaneous ablation of Rb gene. Since alterations of p53-dependent pathway are common hallmarks of aggressive, poor prognostic human cancers, these mouse models can recapitulate the molecular features of some of these human malignancies. To evaluate this possibility, gene expression microarray analysis was performed in mouse samples. The mouse tumors display increased expression of cell cycle and chromosomal instability associated genes. Remarkably, they are also enriched in human embryonic stem cell gene signatures, a characteristic feature of human aggressive tumors. Using cross-species comparison and meta-analytical approaches, we also observed that spontaneous mouse tumors display robust similarities with gene expression profiles of human tumors bearing mutated TP53, or displaying poor prognostic outcome, from multiple body tissues. We have obtained a 20-gene signature whose genes are overexpressed in mouse tumors and can identify human tumors with poor outcome from breast cancer, astrocytoma and multiple myeloma. This signature was consistently overexpressed in additional mouse tumors using microarray analysis. Two of the genes of this signature, AURKA and UBE2C, were validated in human breast and cervical cancer as potential biomarkers of malignancy. Our analyses demonstrate that these mouse models are promising preclinical tools aimed to search for malignancy biomarkers and to test targeted therapies of prospective use in human aggressive tumors and/or with p53 mutation or inactivation.
Gene expression profiling of mouse p53-deficient epidermal carcinoma defines molecular determinants of human cancer malignancy.
Age, Specimen part
View SamplesThe specific ablation of Rb1 gene in stratified epithelia (RbF/F;K14cre) promotes proliferation and altered differentiation but is insufficient to produce spontaneous tumors. The pRb relative, p107, compensates some of the functions of pRb in these tissues, however RbF/F;K14cre;p107-/- mice die postnatally. Acute pRb loss in stratified epithelia, using an inducible mouse model (RbF/F;K14creERTM), shows that p107 exerts specific tumor suppressor functions in its absence. After simultaneous absence of pRb and p107, p53 transcriptional function is impaired and Pten expression is reduced. All mutant mice develop spontaneous squamous tumors carcinomas rapidly. Gene expression analysis of mouse tumors, besides supporting the impaired p53 function and the susceptibility to Akt/mTOR inhibitors, also revealed significant overlap with human squamous carcinomas. Thus, RbF/F;K14creERTM;p107-/- may constitute a new mouse model for these malignancies. Collectively, these data demonstrate the existence of a previously unreported functional connection between pRb, Pten and p53 tumor suppressors, through p107, of a particular relevance in squamous tumor development.
A novel tumor suppressor network in squamous malignancies.
Specimen part
View SamplesHomologue of Enhancer-of-split 1 (Hes1) is a transcription factor that regulates neuronal plasticity, promoting the growth of dendrites and increasing the GABAergic input. A higher expression of Hes1 also results in neuronal resistance against the noxious activity of amyloid beta, the main agent in the advent and progression of the Alzheimer's disease. As a transcription factor, Hes1 controls de expression of many genes. Using the microarray technology we have detected that the expression of one secreted synaptic protein, cerebellin 4 (Cbln4) was particularly increased upon overexpression of Hes1. We also present evidence that Cbln4 plays an essential role in the formation and maintenance of inhibitory GABAergic connections and that either overexpression of Cbln4 in cultured hippocampal neurons or the application of recombinant Cbln4 to the cultures increased the number of GABAergic varicosities and rescued neurons from amyloid beta induced cell death.
Cerebellin 4, a synaptic protein, enhances inhibitory activity and resistance of neurons to amyloid-β toxicity.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Expression of MALT1 oncogene in hematopoietic stem/progenitor cells recapitulates the pathogenesis of human lymphoma in mice.
Specimen part, Disease
View SamplesEndothelin-1 (ET-1) plays a critical role in connective tissue remodeling by fibroblasts during tissue repair and fibrosis. We investigated the molecular pathways in the transmission of ET-1 signals that lead to features of connective tissue remodeling, in particular the role of FAK (focal adhesion kinase).
Inhibition of focal adhesion kinase prevents experimental lung fibrosis and myofibroblast formation.
Specimen part, Treatment
View SamplesWe are investigating the transcriptional response of mice infected with Helicobacter hepaticus and links to liver cancer
Genetic susceptibility to chronic hepatitis is inherited codominantly in Helicobacter hepaticus-infected AB6F1 and B6AF1 hybrid male mice, and progression to hepatocellular carcinoma is linked to hepatic expression of lipogenic genes and immune function-associated networks.
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View SamplesMale C57Bl/6J mice were fed 45%kcal fat diet (HF) or regular rodent chow (NC) from 4 weeks to 16 weeks of age. Gene expression was compared between RNA obtained from pancreatic islets of HF fed mice and NC mice.
Alterations of pancreatic islet structure, metabolism and gene expression in diet-induced obese C57BL/6J mice.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Foxl2 functions in sex determination and histogenesis throughout mouse ovary development.
Sex, Subject
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