Search results for "mito"
showing 10 items of 2513 documents
Evidence for cryptic glacial refugia from North American mountain sheep mitochondrial DNA
2006
The separation of populations by ice sheets into large refugia can account for much of the genetic diversity found in present day populations. The evolutionary implications of small glacial refugia have not been as thoroughly explored. To examine refugial origins of North American mountain sheep Ovis spp., we analyzed a 604 bp portion of the mitochondrial DNA (mtDNA) control region from 223 O. dalli and O. canadensis. Major refugia were identified in eastern Beringia and southern North America, and we found evidence for two smaller refugia situated between the Laurentide and Cordilleran glaciers. Our results are the first to demonstrate support for survival of any organism in the latter two…
X Chromosome Contribution to the Genetic Architecture of Primary Biliary Cholangitis
2021
Background & aims: Genome-wide association studies in primary biliary cholangitis (PBC) have failed to find X chromosome (chrX) variants associated with the disease. Here, we specifically explore the chrX contribution to PBC, a sexually dimorphic complex autoimmune disease. Methods: We performed a chrX-wide association study, including genotype data from 5 genome-wide association studies (from Italy, United Kingdom, Canada, China, and Japan; 5244 case patients and 11,875 control individuals). Results: Single-marker association analyses found approximately 100 loci displaying P < 5 × 10-4, with the most significant being a signal within the OTUD5 gene (rs3027490; P = 4.80 × 10-6; odds…
SAHA induces apoptosis in hepatoma cells and synergistically interacts with the proteasome inhibitor Bortezomib.
2007
Histone deacetylase (HDAC) inhibitors represent a promising group of anticancer agents. This paper shows that the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) stimulated at 5-10 microM apoptosis in human hepatoma HepG2 and Huh6 cells, but was ineffective in primary human hepatocytes (PHH). In HepG2 cells SAHA induced the extrinsic apoptotic pathway, increasing the expression of both FasL and FasL receptor and causing the activation of caspase-8. Moreover, SAHA enhanced the level of Bim proteins, stimulated alternative splicing of the Bcl-X transcript with the expression of the proapoptotic Bcl-Xs isoform, induced degradation of Bid into the apoptotic factor t-Bid and dephosphorylat…
Ionizing radiation but not anticancer drugs causes cell cycle arrest and failure to activate the mitochondrial death pathway in MCF-7 breast carcinom…
2001
There is considerable evidence that ionizing radiation (IR) and chemotherapeutic drugs mediate apoptosis through the intrinsic death pathway via the release of mitochondrial cytochrome c and activation of caspases -9 and -3. Here we show that MCF-7 cells that lack caspase-3 undergo a caspase-dependent apoptotic cell death in the absence of DNA fragmentation and alpha-fodrin cleavage following treatment with etoposide or doxorubicin, but not after exposure to IR. Re-expression of caspase-3 restored DNA fragmentation and alpha-fodrin cleavage following drug treatment, but it did not alter the radiation-resistant phenotype of these cells. In contrast to the anticancer drugs, IR failed to induc…
Abstract 4662: Shikonin causes cancer cell death by inducing mitochondrial dysfunction
2012
Abstract Shikonin, a naturally occurring napthoquinone, has been used in herbal formulations for the treatment of several inflammatory diseases in Traditional Chinese Medicine since decades. In recent studies, shikonin revealed remarkable anticancer activities and thereby is a promising candidate for cancer chemotherapy. However, the underlying cellular mechanisms and targets of shikonin are still unknown. Here, we showed that shikonin indeed exhibits strong cytotoxic effects on a panel of 15 different cancer cell lines also containing multi-drug resistant cells. The strongest effects were obtained on U937 leukemia cells. To better understand the underlying mechanisms, we performed a whole …
Mitochondrial chaperones in cancer: From molecular biology to clinical diagnostics
2006
Mitochondria are cell organelles involved in processes of cell life and death, and therefore also in tumoral transformation. Indeed, mitochondria dysfunction is a prominent feature of cancer cells. Mitochondrial proteins and DNA have also been previously studied as markers of tumorigenesis. Heat shock proteins (HSPs) are ubiquitous evolutionary conserved proteins. HSPs enhance their expression in stressed cells and they are involved in gene expression regulation, DNA replication, signal transduction, differentiation, apoptosis, cellular senescence or immortalization. This review reflects recent views on the role of some mitochondrial molecular chaperones as prohibitin, mortalin and HSP60/HS…
Ultraviolet light-induced DNA damage triggers apoptosis in nucleotide excision repair-deficient cells via Bcl-2 decline and caspase-3/-8 activation.
2001
Ultraviolet (UV) light is a potent mutagenic and genotoxic agent. Whereas DNA damage induced by UV light is known to be responsible for UV-induced genotoxicity, its role in triggering apoptosis is still unclear. We addressed this issue by comparing nucleotide excision repair (NER) deficient 27-1 and 43-3B Chinese hamster (CHO) cells with the corresponding wild-type and ERCC-1 complemented cells. It is shown that NER deficient cells are dramatically hypersensitive to UV-C induced apoptosis, indicating that DNA damage is the major stimulus for the apoptotic response. Apoptosis triggered by UV-C induced DNA damage is related to caspase- and proteosome-dependent degradation of Bcl-2 protein. Th…
Autophagy and mitochondrial alterations in human retinal pigment epithelial cells induced by ethanol: implications of 4-hydroxy-nonenal
2014
Retinal pigment epithelium has a crucial role in the physiology and pathophysiology of the retina due to its location and metabolism. Oxidative damage has been demonstrated as a pathogenic mechanism in several retinal diseases, and reactive oxygen species are certainly important by-products of ethanol (EtOH) metabolism. Autophagy has been shown to exert a protective effect in different cellular and animal models. Thus, in our model, EtOH treatment increases autophagy flux, in a concentration-dependent manner. Mitochondrial morphology seems to be clearly altered under EtOH exposure, leading to an apparent increase in mitochondrial fission. An increase in 2′,7′-dichlorofluorescein fluorescenc…
Multivalent DR5 peptides activate the TRAIL death pathway and exert tumoricidal activity.
2010
Abstract Ongoing clinical trials are exploring anticancer approaches based on signaling by TRAIL, a ligand for the cell death receptors DR4 and DR5. In this study, we report on the selective apoptotic effects of multivalent DR5 binding peptides (TRAILmim/DR5) on cancer cells in vitro and in vivo. Surface plasmon resonance revealed up to several thousand-fold increased affinities of TRAILmim/DR5-receptor complexes on generation of divalent and trivalent molecules, the latter of which was achieved with a conformationally restricted adamantane core. Notably, only multivalent molecules triggered a substantial DR5-dependent apoptotic response in vitro. In tumor models derived from human embryoni…
WIN induces apoptotic cell death in human colon cancer cells through a block of autophagic flux dependent on PPARγ down-regulation.
2014
Cannabinoids have been reported to possess anti-tumorigenic activity in cancer models although their mechanism of action is not well understood. Here, we show that the synthetic cannabinoid WIN55,212-2 (WIN)-induced apoptosis in colon cancer cell lines is accompanied by endoplasmic reticulum stress induction. The formation of acidic vacuoles and the increase in LC3-II protein indicated the involvement of autophagic process which seemed to play a pro-survival role against the cytotoxic effects of the drug. However, the enhanced lysosomal membrane permeabilization (LMP) blocked the autophagic flux after the formation of autophagosomes as demonstrated by the accumulation of p62 and LC3, two ma…