Search results for "IAP"
showing 10 items of 554 documents
Expression of the IAPs in multidrug resistant tumor cells
2003
We have investigated the expression of the IAPs (inhibitory of apoptosis proteins) in the human HL-60 leukemia and in its multidrug resistant, P-glycoprotein (P-gp) over-expressing variant, HL-60R. HL-60R exhibits resistance to apoptosis induced from P-gp substrate drugs and also from other triggers (cisplatin, TNF-alpha, Fas ligation, TRAIL, IFN-gamma and serum starvation) not related to the multidrug transporter. Except for c-IAP-1 mRNA, HL-60R significantly over-expressed both the mRNAs and the proteins of all the IAPs studied, i.e. c-IAP-1, c-IAP-2, XIAP, NAIP and survivin. Determination of the DNA-binding capacity of NF-kappaB (p50 or p65 subunits) indicated that, while HL-60 cells sho…
Antitumor effects of curcumin, alone or in combination with cisplatin or doxorubicin, on human hepatic cancer cells. Analysis of their possible relat…
2005
The hepatic cancer HA22T/VGH cell line, which constitutively expresses activated nuclear factor-kappaB (NF-kB), was chosen as a model to examine the antitumor activity of curcumin, also in relationship to its possible influences on the activation of the transcription factor and on the expression of the inhibitory of apoptosis proteins (IAPs) and of other NF-kB target genes. Curcumin exerted cell growth inhibitory and apoptotic effects, related, at least part, to free radical generation and mainly dependent on caspase-9 and -3 activation. The combination of curcumin with cisplatin resulted in a synergistic antitumor activity and that with doxorubicin in additivity or sub-additivity. Curcumin…
Immune escape of AKT overexpressing ovarian cancer cells
2012
Platinum-resistance is the most crucial problem for treatment of ovarian cancer. There is a clinical need for new treatment strategies which overcome platinum resistance. As survival is strongly influenced by immunological parameters, immunotherapeutic strategies appear promising. Therefore a better understanding of the interaction between ovarian tumour cells and cells of the immune system is a necessary prerequisite. In the present study we aimed to enlighten the interactions between platinum resistant and platinum sensitive ovarian cancer cells and natural-killer (NK)-cells. Modified FATAL assay was used for determining the killing efficiency of NK-cells for the parental A2780 cells and …
Autocrine production of interleukin-4 and interleukin-10 is required for survival and growth of thyroid cancer cells.
2006
AbstractAlthough CD95 and its ligand are expressed in thyroid cancer, the tumor cell mass does not seem to be affected by such expression. We have recently shown that thyroid carcinomas produce interleukin (IL)-4 and IL-10, which promote resistance to chemotherapy through the up-regulation of Bcl-xL. Here, we show that freshly purified thyroid cancer cells were completely refractory to CD95-induced apoptosis despite the consistent expression of Fas-associated death domain and caspase-8. The analysis of potential molecules able to prevent caspase-8 activation in thyroid cancer cells revealed a remarkable up-regulation of cellular FLIPL (cFLIPL) and PED/PEA-15, two antiapoptotic proteins whos…
Changes in gene expression linked with adult reproductive diapause in a northern malt fly species: a candidate gene microarray study
2010
Abstract Background Insect diapause is an important biological process which involves many life-history parameters important for survival and reproductive fitness at both individual and population level. Drosophila montana, a species of D. virilis group, has a profound photoperiodic reproductive diapause that enables the adult flies to survive through the harsh winter conditions of high latitudes and altitudes. We created a custom-made microarray for D. montana with 101 genes known to affect traits important in diapause, photoperiodism, reproductive behaviour, circadian clock and stress tolerance in model Drosophila species. This array gave us a chance to filter out genes showing expression…
Neurosecretion in the Frontal Ganglion of the Stick Insect, Carausius morosus
1978
The presence of neurosecretory cells in the frontal ganglion (FG) has been demonstrated only in the Lepidoptera Bombyx (BOUNHIOL et al., 1953), Manduca (BORG et al., 1973; BELL et al., 1974), and Diatraea (YIN and CHIPPENDALE, 1975). In Manduca and Diatraea the neurosecretory material of the FG is apparently involved in the regulation of diapause.
Expression of IAPs and alternative splice variants in hepatocellular carcinoma tissues and cells.
2005
IAPs (inhibitors of apoptosis proteins) might have a major role in the apoptotic resistance that marks many cancers. The studies on IAPs in human HCC have focused on survivin or XIAP, indicating that their new or increased expression in this tumor is associated with a more unfavorable prognosis. The present results corroborate these findings, emphasizing the role that the coordinated expression of different IAPs and alternative splice variants might play in the adverse biology of hepatocellular carcinoma.
Resveratrol reduces oxidative stress and cell death and increases mitochondrial antioxidants and XIAP in PC6.3-cells.
2010
Resveratrol, a polyphenol derived e.g. from red grapes, has been shown to mediate several positive biological actions such as protection of cells against oxidative stress. It can also influence cell signaling, but the mechanisms behind its antioxidant properties are largely unknown. Here we show that RSV reduces oxidative stress and enhances cell survival in PC6.3 cells depending on the concentration. In these cells, RSV increased the levels of antioxidants, SOD2 and TRX2, and of X chromosome-linked inhibitor of apoptosis protein. RSV also activated NFκB signaling as shown using luciferase reporter constructs. These findings show that RSV regulates oxidative stress and mitochondrial antioxi…
MOLECULAR BASIS OF DRUG PHOTOTOXICITY: PHOTOSENSITIZED CELL DAMAGE BY THE MAJOR PHOTOPRODUCT OF TIAPROFENIC ACID
1994
Tiaprofenic acid is a photosensitizing nonsteroidal anti-inflammatory drug, whose major photoproduct (decarboxytiaprofenic acid) is also a potent photosensitizer. Because of the lack of the carboxylate moiety, this photoproduct is more lipophilic and might bind more efficiently to cell membranes, thereby causing phototoxic damage. To verify the feasibility of this hypothesis, we have prepared the 3H-labeled analogs of tiaprofenic acid and its photoproduct and examined the binding, persistence and phototoxicity of the photoproduct using poorly metabolizing (fibroblasts) and actively metabolizing cells (hepatocytes). The photoproduct of tiaprofenic acid accumulates in both cell types as it is…
Characterisation, analysis of expression and localisation of the opsin gene repertoire from the perspective of photoperiodism in the aphid Acyrthosip…
2017
Organisms exhibit a wide range of seasonal responses as adaptions to predictable annual changes in their environment. These changes are originally caused by the effect of the Earth's cycles around the sun and its axial tilt. Examples of seasonal responses include floration, migration, reproduction and diapause. In temperate climate zones, the most robust variable to predict seasons is the length of the day (i.e. the photoperiod). The first step to trigger photoperiodic driven responses involves measuring the duration of the light-dark phases, but the molecular clockwork performing this task is poorly characterized. Photopigments such as opsins are known to participate in light perception, b…