Search results for " Suppressor"
showing 10 items of 462 documents
Tumor suppression inDrosophila is causally related to the function of thelethal(2)tumorous imaginal discs gene, adnaJ homolog
1995
The Drosophila melanogaster tumor suppressor gene lethal(2)tumorous imaginal discs (l(2)tid) causes in homozygotes malignant growth of cells of the imaginal discs and the death of the mutant larvae at the time of puparium formation. We describe the molecular cloning of the l(2)tid+ gene and its temporal expression pattern in the wild-type and mutant alleles. Germ line rescue of the tumor phenotype was achieved with a 7.0 kb Hindlll-fragment derived from the polytene chromosome band 59F5. The l(2)tid+ gene spans approximately 2.5 kb of genomic DNA. The protein coding region, 1,696 bps long, is divided by an intron into two exons. The predicted Tid56 protein contains 518 amino acids and posse…
Cloning, structure, cellular localization, and possible function of the tumor suppressor gene lethal(3)malignant blood neoplasm-1 of Drosophila melan…
1994
The tumor suppressor gene, lethal(3)malignant blood neoplasm-1+, of Drosophila melanogaster is required for the differentiation of the phagocytic blood-cell type, the plasmatocyte. In the homozygously mutated state it causes the malignant transformation of these blood cells. We present here the cloning, sequencing, structure, and expression of the l(3)mbn-1+ gene during development. The cloned gene was identified by germ-line transformation, generation of revertants, and the detection of the corresponding mRNA in blood cells and other tissues. Homologies of the G-S-rich C-terminus of the putative MBN83 protein to human cytokeratins K1, K10, and mouse loricrin were found. The structure and p…
The human p53 gene mutated at position 249per se is not sufficient to immortalize human liver cells
1999
A particular point mutation of the tumor suppressor gene p53, namely a G→T transversion at the third base of codon 249, is frequently detected in primary hepatocellular carcinomas from patients living in areas where the levels of dietary exposure to aflatoxin B 1 and the rates of infection with the hepatitis B virus are very high. Very recently, a nontumorigenic liver epithelial cell line (HACL-1) with a finite life-span and expressing a number of hepatocyte-specific markers was established from a human hepatocellular adenoma in our laboratory. To analyze the role of mutated p53 in the immortalization of human liver cells, we transfected HACL-1 cells with an expression vector containing a h…
Cytotoxic Activity of Organotin(IV) Derivatives with Triazolopyrimidine Containing Exocyclic Oxygen Atoms
2020
In this study cytotoxicity of organotin(IV) compounds with 1,2,4-triazolo[1,5-a]pyrimidines, Me3Sn(5tpO) (1), n-Bu3Sn(5tpO) (2), Me3Sn(mtpO) (3), n-Bu3Sn(mtpO) (4), n-Bu3Sn(HtpO2) (5), Ph3Sn(HtpO2) (6) where 5HtpO = 4,5-dihydro-5-oxo-[1,2,4]triazolo-[1,5-a]pyrimidine, HmtpO = 4,7-dihydro-5-methyl-7-oxo-[1,2,4]triazolo-[1,5-a]pyrimidine, and H2tpO2 = 4,5,6,7-tetrahydro-5,7- dioxo-[1,2,4]triazolo-[1,5-a]-pyrimidine, was assessed on three different human tumor cell lines: HCT-116 (colorectal carcinoma), HepG2 (hepatocarcinoma) and MCF-7 (breast cancer). While 1 and 3 were inactive, compounds 2, 4, 5 and 6 inhibited the growth of the three tumor cell lines with IC50 values in the submicromolar …
Topoisomerase II{alpha}-dependent and -independent apoptotic effects of dexrazoxane and doxorubicin.
2009
Abstract Coadministration of the iron chelator dexrazoxane reduces by 80% the incidence of heart failure in cancer patients treated with anthracyclines. The clinical application of dexrazoxane is limited, however, because its ability to inhibit topoisomerase IIα (TOP2A) is feared to adversely affect anthracycline chemotherapy, which involves TOP2A-mediated generation of DNA double-strand breaks (DSB). Here, we investigated the apoptotic effects of dexrazoxane and the anthracycline doxorubicin, alone and in combination, in a tumor cell line with conditionally regulated expression of TOP2A. Each drug caused apoptosis that was only partly dependent on TOP2A. Unexpectedly, dexrazoxane was found…
Mitochondrial localization and temporal expression of the Drosophila melanogaster DnaJ homologous tumor suppressor Tid50
1998
The Drosophila melanogaster tumor suppressor gene lethal(2)tumorous imaginal discs (tid) was identified as a homolog of all dnaJ-like genes known to date which have been well preserved in evolution. Homozygous D. melanogaster l(2)tid mutants l(2)tid1, l(2)tid2 and l(2)tid3 are characterized by neoplastic transformation of the adult integumental primordia, the imaginal discs, and the death at the time of puparium formation. The first part of this study is concerned with the identification and subcellular localization of the l(2)tid-encoded protein, Tid50. The second part examines its tissue specific expression during wild-type development and in tumorous imaginal discs. To specify the functi…
A temperature-sensitive brain tumor suppressor mutation of Drosophila melanogaster: Developmental studies and molecular localization of the gene
1993
The recessive-lethal, temperature-sensitive (ts) mutation of the tumor suppressor gene lethal(3)malignant brain tumor (l(3)mbt) causes in a single step the malignant transformation of the adult optic neuroblasts and ganglion mother cells in the larval brain at the restrictive temperature of 29 degrees C. The transformed cells are differentiation-incompetent and grow autonomously in a lethal and invasive fashion in situ in the brain as well as after transplantation in vivo into wild-type adult hosts. The imaginal discs show epithelial overgrowth. At the permissive temperature of 22 degrees C development is completely normal. The ts-period of gene activity responsible for 100% brain tumor sup…
Lymphatic endothelial progenitors bud from the cardinal vein and intersomitic vessels in mammalian embryos.
2012
Abstract The lymphatic vasculature preserves tissue fluid balance by absorbing fluid and macromolecules and transporting them to the blood vessels for circulation. The stepwise process leading to the formation of the mammalian lymphatic vasculature starts by the expression of the gene Prox1 in a subpopulation of blood endothelial cells (BECs) on the cardinal vein (CV) at approximately E9.5. These Prox1-expressing lymphatic endothelial cells (LECs) will exit the CV to form lymph sacs, primitive structures from which the entire lymphatic network is derived. Until now, no conclusive information was available regarding the cellular processes by which these LEC progenitors exit the CV without co…
Effects of electrical and mechanical parameters on the transient voltage stability of a fixed speed wind turbine
2011
Abstract In this paper the dynamic behaviour of a wind turbine connected to the grid is examined. The model of the fixed speed wind turbine has been developed with the Simulink simulation tool (Matlab Inc.) It is composed of the induction generator, the shaft system, an aerodynamic model of the wind turbine rotor and the pitch control system. Using this model, a three-phase fault is applied close to the wind turbine and cleared by disconnecting the faulty line. The rigorous implementation of the simulink model allowed the authors to evaluate the exact dependence of various electrical parameters for the induction generator on voltage stability. Furthermore, the effects of wind turbine mechan…
Wind Turbine Mechanical Characteristics and Grid Parameters Influence on the Transient Voltage Stability of a Fixed Speed Wind Turbine
2008
This paper describes the effect of wind turbine mechanical characteristic of construction and grid parameters on the transient voltage stability of a fixed speed wind turbine (FSWT) connected to a simple grid. The model of FSWT has been developed in Matlab/Simulink. Using this model, a three-phase fault is applied close to the wind turbine (WT) and cleared by disconnecting the faulted line. The effects of mechanical construction of WT and of grid parameters on the voltage stability of this simple case are evaluated and discussed. The considered parameters are the inertia coefficient of the WT, the short-circuit power at the connection bus, the hub-generator resonant frequency, the wind spee…