Search results for "Phenotype"

A role for the transcription intermediary factor 2 in zebrafish myelopoiesis.

2007

Objective TIF2 is fused with MOZ in the inv(8)(p11q13) acute myeloid leukemia. TIF2, member of the p160 family, is a histone acetyl transferase (HAT). Deletion of p160 genes were performed in mice. Some observations suggest that p160 family members may perform overlapping functions in mice. Therefore, we decided to choose the zebrafish model to study TIF2. The aim of this study was to characterize the role of this HAT during embryonic development. Material and Methods We use antisense, morpholino-modified oligomers to transiently knockdown tif2 gene, thus determining whether TIF2 plays a role in zebrafish early development. Results We show that tif2 is involved in embryogenesis and in primi…

Abstract 766: Suppression of gefitinib-induced EMT in EGFR mutant NSCLC preferentially selects for acquired T790M

2015

Abstract Activating EGFR mutations in non-small lung cancer (NSCLC) confer sensitivity to reversible EGFR tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib. Despite promising initial response acquired resistance develops mediated by the emergence of the secondary T790M mutation or by focal amplification of MET. An epithelial-to-mesenchymal transition (EMT) is clinically linked to NSCLCs with acquired EGFR TKI resistance. The exact mechanisms of EGFR TKI resistance with EMT phenotype remain elusive; therefore, we attempted to develop a strategy to prevent the emergence of EGFR TKI resistance with EMT phenotype. In order to mimic the development of acquired EGFR TKI resista…

Parathyroid Hormone-Related Protein (PTHrP): A Key Regulator of Life/Death Decisions by Tumor Cells with Potential Clinical Applications

2010

Parathyroid hormone-related protein (PTHrP), classically regarded as the mediator of the humoral hypercalcemia of malignancy syndrome, is a polyhormone that undergoes proteolytic processing into smaller bioactive forms. These bioactive forms comprise an N-terminal- as well as midregion- and C-terminal peptides, which have been shown to regulate various biological events, such as survival, proliferation and differentiation, in diverse cell model systems, both normal and pathological. A number of experimental data have demonstrated that PTHrP is also able to modulate tumor-relevant phenotypic expressions, thereby playing a role in early and advanced tumorigenesis, and in the response to treat…

O78. Which phenotype adds to cardiovascular risk assessment? Lessons from the Gutenberg heart study: A prospective, population-based cohort study in …

2008

Intestinal epithelial HuR modulates distinct pathways of proliferation and apoptosis and attenuates small intestinal and colonic tumor development.

2014

Abstract HuR is a ubiquitous nucleocytoplasmic RNA-binding protein that exerts pleiotropic effects on cell growth and tumorigenesis. In this study, we explored the impact of conditional, tissue-specific genetic deletion of HuR on intestinal growth and tumorigenesis in mice. Mice lacking intestinal expression of HuR (Hur IKO mice) displayed reduced levels of cell proliferation in the small intestine and increased sensitivity to doxorubicin-induced acute intestinal injury, as evidenced by decreased villus height and a compensatory shift in proliferating cells. In the context of Apcmin/+ mice, a transgenic model of intestinal tumorigenesis, intestinal deletion of the HuR gene caused a three-fo…

Abstract 3193: Development of a colon cancer model system reveals epithelial contribution to poor-prognosis gene signatures

2016

Abstract Background: Recent consensus on molecular classification categorizes colorectal cancer (CRC) into 4 robust subtypes: CMS1 (epithelial-MSI), CMS2 (epithelial-canonical), CMS3 (epithelial-metabolic) and CMS4 (mesenchymal)1. CMS4 is linked to poor cancer prognosis and characterized by mesenchymal and epithelial-to-mesenchymal transition (EMT) gene expression2,3. Recent attempts to deconvolute the transcriptome from CRC tumors have suggested that the mesenchymal gene expression results from a large stromal compartment and is not due to epithelial cells with EMT-like features4,5. This challenges the classic notion that tumor cells activate the EMT program to undergo trans-differentiatio…

Bmi1 and Cell of Origin Determinants of Brain Tumor Phenotype

2007

Glioblastomas frequently express oncogenic EGFR and loss of the Ink4a/Arf locus. Bmi1, a positive regulator of stem cell self renewal, may be critical to drive brain tumor growth. In this issue of Cancer Cell, Bruggeman and colleagues suggest that brain tumors with these molecular alterations can be initiated in both neural precursor and differentiated cell compartments in the absence of Bmi1; however, tumorigenicity is reduced, and tumors contain fewer precursor cells. Surprisingly, tumors appear less malignant when initiated in precursor cells. Bmi1-deficient tumors also had fewer neuronal lineage cells, suggesting a role for Bmi1 in determination of cell lineage and tumor phenotype.

Partial restoration of pre-transformation levels of lysyl oxidase and transin mRNAs in phenotypic ras revertants.

1995

Neoplastic transformation mediated by ras oncogenes is associated with deregulated expression of genes encoding, for example, various proteases, lysyl oxidase, and smooth-muscle α-actin. To define the role of these genes in the initiation or maintenance of the ras-transformed state, we compared their steady-state mRNA levels in two different sets of preneoplastic fibroblast lines, ras-transformed clones, and phenotypic revertants derived from them. Compared with the preneoplastic fibroblasts, the ras-transformed derivatives exhibited elevated levels of cathepsin L (major excreted protein), transin (stromelysin I, matrix metalloproteinase–3), and collagenase I (matrix metalloproteinase–1) mR…

Abstract LB-C21: CXCR7 expression is necessary for the maintenance of mesenchymal phenotype in acquired EGFR TKI resistance in NSCLC

2015

Abstract Activating EGFR mutations in non-small lung cancer (NSCLC) confer sensitivity to reversible EGFR tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib. Despite promising initial response, acquired resistance develops mediated by the emergence of the secondary T790M mutation or by focal amplification of MET. An epithelial-to-mesenchymal transition (EMT) is clinically linked to NSCLCs with acquired EGFR TKI resistance. The exact mechanisms of EGFR TKI resistance with EMT phenotype remain elusive; therefore, we have engineered EGFR-mutated NSCLC cell lines with mesenchymal phenotype by stably depleting E-Cadherin or by overexpressing Snail or chronically exposing the ce…

Tracheal development and the von Hippel-Lindau tumor suppressor homolog in Drosophila.

2000

von Hippel-Lindau disease is a hereditary cancer syndrome. Mutations in the VHL tumor suppressor gene predispose individuals to highly vascularized tumors. However, VHL-deficient mice die in utero due to a lack of vascularization in the placenta. To resolve the contradiction, we cloned the Drosophila VHL homologue (d-VHL) and studied its function. It showed an overall 50% similarity to the human counterpart and 76% similarity in the crucial functional domain: the elongin C binding site. The putative d-VHL protein can bind Drosophila elongin C in vitro. During embryogenesis, d-VHL is expressed in the developing tracheal regions where tube outgrowth no longer occurs. Reduced d-VHL activity (u…