Search results for "programmed cell death"
showing 10 items of 609 documents
Endoplasmic reticulum stress is involved in response of human laryngeal carcinoma cells to carboplatin but is absent in carboplatin resistant cells
2013
The major obstacle of successful tumor treatment with carboplatin (CBP) is the development of drug resistance. In the present study, we found that following treatment with CBP the amount of platinum which enters the human laryngeal carcinoma (HEp2)-derived CBP- resistant (7T) cells is reduced relative to the parental HEp2. As a consequence, the formation of reactive oxidative species (ROS) is reduced, the induction of endoplasmic reticulum (ER) stress is diminished, the amount of inter- and intrastrand cross-links is lower, and the induction of apoptosis is depressed. In HEp2 cells, ROS scavenger tempol, inhibitor of ER stress salubrinal, as well as gene silencing of ER stress marker CCAAT/…
Programmed cell death in the embryonic central nervous system of Drosophila melanogaster.
2006
Although programmed cell death (PCD) plays a crucial role throughout Drosophila CNS development, its pattern and incidence remain largely uninvestigated. We provide here a detailed analysis of the occurrence of PCD in the embryonic ventral nerve cord (VNC). We traced the spatio-temporal pattern of PCD and compared the appearance of, and total cell numbers in,thoracic and abdominal neuromeres of wild-type and PCD-deficient H99mutant embryos. Furthermore, we have examined the clonal origin and fate of superfluous cells in H99 mutants by DiI labeling almost all neuroblasts, with special attention to segment-specific differences within the individually identified neuroblast lineages. Our data r…
Anandamide-induced apoptosis in Chang liver cells involves ceramide and JNK/AP-1 pathway
2006
In the present study we demonstrate that anandamide, the most important endogenous cannabinoid, markedly induced apoptosis in Chang liver cells, an immortalized non-tumor cell line derived from normal liver tissue, while it induced only modest effects in a number of hepatoma cell lines. The apoptotic effect was reduced by methyl-beta-cyclodextrin, a membrane cholesterol depletor, suggesting an interaction between anandamide and the membrane microdomains named lipid rafts. Anandamide effects were mediated by the production of ceramide, as demonstrated by experiments performed with the sphingomyelinase inhibitor, desipramine, or with the sphingomyelinase activator, melittin. This conclusion w…
ATRIP protects progenitor cells against DNA damage in vivo
2020
AbstractThe maintenance of genomic stability during the cell cycle of progenitor cells is essential for the faithful transmission of genetic information. Mutations in genes that ensure genome stability lead to human developmental syndromes. Mutations in Ataxia Telangiectasia and Rad3-related (ATR) or in ATR-interacting protein (ATRIP) lead to Seckel syndrome, which is characterized by developmental malformations and short life expectancy. While the roles of ATR in replicative stress response and chromosomal segregation are well established, it is unknown how ATRIP contributes to maintaining genomic stability in progenitor cells in vivo. Here, we generated the first mouse model to investigat…
Plastid-nuclear complexes in the photosynthesizing cells from their mitosis up to programmed death
2013
Permanent plastid-nuclear complexes (PNCs) exist in tobacco cells from their mitosis up to programmed cell death (PCD). PNCs in senescing cells of tobacco leaves were typical by enclosure of peroxisomes and mitochondria among chloroplasts which were in contact with nucleus. Such a complex position provides simultaneous interaction of these organelles and direct regulation of metabolism and PCD avoiding the cytosol.
Impact Of Hypoxic And Acidic Extracellular Conditions On Cytotoxicity Of Chemotherapeutic Drugs
2007
In the microenvironment of solid growing tumors, pronounced hypoxia or extracellular acidosis is commonly found The aim of this study was the analysis of the cytotoxic effect of different chemotherapeutic agents (cisplatin, daunorubicin, docetaxel) under these conditions in vitro Prostate carcinoma cells (R3327-AT1) were exposed to hypoxia (pO 2 05 mmHg) or extracellular acidosis (pH=66) for 6h After 3h, cytotoxic drugs were added The cytotoxic effect was assessed by measuring caspase 3-activity (apoptosis), LDH release (necrosis) and repopulation of the cells after chemotherapy (cell death) Compared to aerobic control conditions, severe hypoxia over 6h per se led to a slight increase in ap…
Impact of Hypoxia-Related Tumor Acidosis on Cytotoxicity of Different Chemotherapeutic Drugs In Vitro and In Vivo
2014
Extracellular acidosis in tumors leads to an activation of the p-glycoprotein (Pgp) drug transporter. In the present study the cytotoxicity of different chemotherapeutic drugs and its dependence on the Pgp activity during acidosis were analyzed in vitro and in vivo. Treating R3327-AT1, Pgp-positive tumor cells at pH 7.4 with daunorubicin, cisplatin or docetaxel led to marked apoptosis induction and cell death. Under acidic (pH 6.6) conditions cytotoxicity of daunorubicin or docetaxel was significantly reduced whereas cisplatin-induced cell death was almost pH-independent. Inhibiting Pgp with verapamil reversed the acidosis-induced chemoresistance against daunorubicin and docetaxel. The Pgp …
Low doses of paclitaxel potently induce apoptosis in human retinoblastoma Y79 cells by up-regulating E2F1.
2008
Paclitaxel (PTX) is an anticancer drug currently in phase II clinical trials. This study shows for the first time that low doses of PTX (5 nM) potently induce apoptosis in human retinoblastoma Y79 cells. The effect of PTX is accompanied by a potent induction of E2F1 which appears to play a critical role in the effects induced by PTX. PTX induced a dose- and time-dependent effect, with G2/M arrest, cyclines A, E and B1 accumulation and a marked modification in the status of Cdc2-cyclin B1 complex, the major player of the G2/M checkpoint. Apoptosis followed G2/M arrest. An early and prolonged increase in p53 expression with its stabilization by phosphorylation and acetylation and its nuclear …
Multiple modes of cell death in neuroendocrine tumors induced by artesunate.
2020
Abstract Background The paucity of effective treatment in neuroendocrine tumors (NETs) encouraged us to investigate the therapeutic value of artesunate (ART) promised by its inhibitory effect against various tumors and broad safety profile. Methods We evaluated the impact of ART on three NET cell lines, BON-1, QGP-1 and NCI-H727 on cellular and molecular levels. Results Our results showed that ART induced endoplasmic reticulum (ER) stress through phosphorylation of eIF2α, which further gave rise to autophagy in all three NET cell lines. Specifically, apoptosis and ferroptosis were also observed in BON-1 cells, which made BON-1 cell line more vulnerable upon ART treatment. The different sens…
Activated kRas protects colon cancer cells from cucurbitacin-induced apoptosis: The role of p53 and p21
2008
Cucurbitacins have been shown to inhibit proliferation in a variety of cancer cell lines. The aim of this study was to determine their biological activity in colon cancer cell lines that do not harbor activated STAT3, the key target of cucurbitacin. In order to establish the role of activated kRas in the responsiveness of cells to cucurbitacins, we performed experiments in isogenic colon cancer cell lines, HCT116 and Hke-3, which differ only by the presence of an activated kRas allele. We compared the activity of 23, 24-dihydrocucurbitacin B (DHCB) and cucurbitacin R (CCR), two cucurbitacins that we recently isolated, with cucurbitacin I (CCI), a cucurbitacin with established antitumorigeni…