Alveolar rhabdomyosarcoma (aRMS) is an aggressive sarcoma of skeletal muscle characterized by expression of the PAX3-FOXO1 fusion gene. Despite its discovery over almost 20 years ago, PAX3-FOXO1 remains an enigmatic tumor driver. Previously, we reported that PAX3-FOXO1 supports aRMS initiation by enabling bypass of cellular senescence. Here, we show that bypass occurs in part by PAX3-FOXO1-mediated upregulation of RASSF4, a Ras-association domain family (RASSF) member, which then suppresses the evolutionarily conserved mammalian Hippo/Mst1 pathway. RASSF4 loss-of-function activates Hippo/Mst1 and inhibits downstream YAP, causing aRMS cell cycle arrest and senescence. This is the first evidence for an oncogenic role for RASSF4, and a novel mechanism for Hippo signaling suppression in human cancer.
Alveolar rhabdomyosarcoma-associated PAX3-FOXO1 promotes tumorigenesis via Hippo pathway suppression.
Cell line, TreatmentView Samples
Shiga toxins (Stxs) are bacterial cytotoxins produced by the enteric pathogens Shigella dysenteriae serotype 1 and some serotypes of Escherichia coli that cause bacillary dysentery and hemorrhagic colitis, respectively. To date, approaches to studying the capacity of Stxs to alter gene expression in intoxicated cells have been limited to individual genes. However, it is known that many of the signaling pathways activated by Stxs regulate the expression of multiple genes in mammalian cells. To expand the scope of analysis of gene expression and to better understand the underlying mechanisms for the various effects of Stxs on cell functions, we carried out comparative microarray analyses to characterize the global transcriptional response of human macrophage-like THP-1 cells to Shiga toxin type 1 (Stx1) and LPS. Data were analyzed using a rigorous combinatorial approach with three separate statistical algorithms. Thirty-six genes met the criteria of up-regulated expression in response to Stx1 treatment with 14 genes uniquely up-regulated by Stx1. Microarray data were validated by real time RT-PCR for genes encoding Egr-1 (transcriptional regulator), COX-2 (inflammation), and DUSP1, 5 and 10 (regulation of MAPK signaling). Stx1-mediated signaling through ERK1/2 and Egr-1 appears to be involved in the increased expression of the proinflammatory mediator TNF-. Activation of COX-2 expression is associated with the increased production of proinflammatory and vasoactive eicosanoids. However, the capacity of Stx1 to increase the expression of genes encoding phosphatases suggests that mechanisms to dampen the macrophage proinflammatory response may be built into host response to the toxins.
Global transcriptional response of macrophage-like THP-1 cells to Shiga toxin type 1.
Specimen part, Cell lineView Samples
Mesothelia, which cover all coelomic organs and body cavities in vertebrates, perform diverse functions in embryonic and adult life. Yet, mesothelia are traditionally viewed as simple, uniform epithelia.
Autotaxin signaling governs phenotypic heterogeneity in visceral and parietal mesothelia.
Specimen partView Samples
Swiss-Webster female mice (Charles River Laboratories, Wilmington, MA) 5-6 weeks of age were infected intranasally with 5 LD50 of either WT or lpp mutant of Y. pestis CO92. Uninfected mice were used as controls. At either 12 or 48 h post infection (p.i.), 3 mice per group were euthanized and the lungs, livers, and spleens were harvested and homogenized in 1 ml of RNALater (Ambion/Applied Biosystems, Austin, TX) using 50-ml tissue homogenizers (Kendell, Mansfield, MA). RNA was isolated from the tissue homogenates and purified using RNAqueous (Ambion). After an overnight precipitation, the RNA was resuspended in 20 ul of diethylpyrocarbonate (DEPC)-treated water and hybridized to Affymetrix GeneChip Mouse Genome 430 2.0 arrays, performed by the Molecular Genomics Core at UTMB Galveston, Texas, per manufacture protocols. The arrays had 45,000 probe sets representing more than 39,000 transcripts derived from ~34,000 well-substantiated mouse genes. The experiments were performed in triplicate (biological replicates), generating a total of 45 arrays.
Comparative Analyses of Transcriptional Profiles in Mouse Organs Using a Pneumonic Plague Model after Infection with Wild-Type Yersinia pestis CO92 and Its Braun Lipoprotein Mutant.
Sex, Specimen part, TimeView Samples
Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infection causes an immune-mediated disease. We have recently shown that SARS-CoV-induced epithelial Calu-3 cytokines could exacerbate and dampen host inflammatory and T cell responses, respectively, through modulating the functions of macrophages and dendritic cells, thereby suggesting that not only are lung epithelial cells the primary cells of SARS-CoV infection, but they also involve in initiating and orchestrating the host innate and adaptive immunity. Comprehensive evaluation of the complex epithelial signaling to SARS-CoV is, thus, crucial for paving the way to better understand SARS pathogenesis and develop the innovative therapeutics against SARS. Here, based on the microarray-based functional genomics, we reported that 2B4 cells, a clonal derivative of Calu-3 cells, elicited a temporal and spatial activation of nuclear factor (NF)kappaB, activator protein (AP)-1 (ATF2/c-Jun), and interferon regulatory factor (IRF)-3/-7 at 12-, 24-, and 48-hrs post infection (p.i.), respectively, resulting in the activation of many antiviral genes, including interferon (IFN)-, -s, SARS-related inflammatory mediators, and various IFN-stimulated genes (ISGs). While elevated responses of IFN- and IFN-s were not detected until 48-hrs p.i., as a consequence of a delayed IRF-3/-7 activation, we showed, for the first time, that both types of IFNs exerted previously under-described non-redundant, complementary, and/or synergistic effects on the epithelial defense against SARS-CoV. Collectively, our results highlight the molecular mechanisms of the sequential activation of virus- and IFN-dependent signaling of lung epithelial cells against SARS-CoV and identify novel cellular targets for future studies, aiming at advancing strategies against SARS.
Dynamic innate immune responses of human bronchial epithelial cells to severe acute respiratory syndrome-associated coronavirus infection.
Cell line, TimeView Samples
Activation of Sonic Hedgehog signaling through expression of a constitutively active Smoothened allele under control of an aP2 adipocyte-restricted transgene in mice gives rise to aggressive skeletal muscle tumors that display the histologic and molecular characteristics of human embryonal rhabdomyosarcoma with high penetrance.
A mouse model of rhabdomyosarcoma originating from the adipocyte lineage.
Specimen partView Samples
Copper-based chemotherapeutic compounds Casiopeinas, have been presented as able to promote selective programmed cell death in cancer cells, thus being proper candidates for targeted cancer therapy. DNA fragmentation and apoptosis -in a process mediated by reactive oxygen species- for a number of tumor cells, have been argued to be the main mechanisms. However, a detailed functional mechanism (a model) is still to be defined and interrogated for a wide variety of cellular conditions; before establishing settings and parameters needed for their wide clinical application.
Whole genome gene expression analysis reveals casiopeína-induced apoptosis pathways.
Cell lineView Samples
Aortic valve calcification is the most common form of valvular heart disease, but the mechanisms of calcific aortic valve disease (CAVD) are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. The aim of this study was to investigate the molecular changes that occur with inhibition of Notch signaling in the aortic valve. Notch signaling pathway members are expressed in adult aortic valve cusps, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs).
Inhibitory role of Notch1 in calcific aortic valve disease.
Specimen partView Samples
Brucella suis infects macrophages and dendritic cells. Wild boars act as reservoirs and carriers of Brucella suis biovar 2, and there is evidence that wild boar can be the main source of infection for domestic pigs through the venereal route. Transmission through this route could be an important path for disesease dissemination. The result from this study will contribute to the overall understanding of the molecular pathogenic mechanisms involved during Brucella suis infection in European wild boar.
Gene expression changes in spleens of the wildlife reservoir species, Eurasian wild boar (Sus scrofa), naturally infected with Brucella suis biovar 2.
Specimen part, DiseaseView Samples
We performed microarray analyses on RNA from mice with isoproterenol-induced cardiac hypertrophy and mice with exercise-induced physiological hypertrophy and identified 865 and 2,534 genes that were significantly altered in pathological and physiological cardiac hypertrophy models, respectively.
Transcriptional profile of isoproterenol-induced cardiomyopathy and comparison to exercise-induced cardiac hypertrophy and human cardiac failure.
Specimen partView Samples