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Matti Narkia

Mitochondrially Targeted Effects of Berberine [Natural Yellow 18, 5,6-dihydro-9,10-dime... - 0 views

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    Mitochondrially targeted effects of berberine [Natural Yellow 18, 5,6-dihydro-9,10-dimethoxybenzo(g)-1,3-benzodioxolo(5,6-a) quinolizinium] on K1735-M2 mouse melanoma cells: comparison with direct effects on isolated mitochondrial fractions. Pereira GC, Branco AF, Matos JA, Pereira SL, Parke D, Perkins EL, Serafim TL, Sardão VA, Santos MS, Moreno AJ, Holy J, Oliveira PJ. J Pharmacol Exp Ther. 2007 Nov;323(2):636-49. Epub 2007 Aug 17. PMID: 17704354 doi: 10.1124/jpet.107.128017 The present work shows that berberine is accumulated by mitochondria of a mouse melanoma cell line, leading to mitochondrial fragmentation and dysfunction, accompanied by decreased cellular energy charge. When the effect was compared with the results obtained on isolated mitochondrial fractions, it is observed that regardless of the system used, berberine is toxic for mitochondria. One major limitation of the present study (as in many others) is the lack of knowledge of the real concentration of berberine that reaches mitochondria in intact cells. Although we do not possess data regarding this aspect, it is wise to speculate that mitochondrial berberine concentrations will be much higher than in the bulk cytosol due to electrophoretic accumulation. We believe that the range of berberine concentrations accumulated by mitochondria in intact cells is within the range of concentrations used on isolated mitochondrial fractions in the present study. The present work not only provides insights on the mechanism by which berberine interferes with tumor cell proliferation, demonstrating previously unknown effects on mitochondrial physiology, but also raises a note of caution on the use of berberine as a nontoxic "natural" over-the-counter medication.
Matti Narkia

DCA and vanadium combination - The DCA Site - Updating You on DCA and Cancer - Dichloro... - 1 views

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    Simultaneously Blocking Glycolysis and Fat Metabolism Can the use of DCA and a fatty acid metabolism blocker together force more cancer cells into using aerobic metabolism? Tim McGough used green tea extract, which contains EGCG, in his fantastic response. DCA works by reactivating mitochondria and shifts metabolism from glycolysis to glucose oxidation. Hopefully the cancer cell will then undergo apoptosis. However, cancer cells have an alternate energy source: fat metabolism. This page explores to possibility of blocking fat metabolism to help force the cell into apoptosis. Oral squamous cell carcinoma is a cancer that does not respond well to DCA. This study, Head and Neck Cancer Cell Lines Are Resistant to Mitochondrial-Depolarization-Induced Apoptosis states: "Results: ΔΨm in head and neck cell lines started to show slight loss of ΔΨm, while HL-60 showed significant loss of ΔΨm after 30 min of treatment. All cell lines demonstrated complete mitochondrial depolarization within 24 h, however, only the control cell line HL-60 underwent apoptosis. In addition, HNSCC cell lines did not demonstrate cytoplasmic cytochrome c release despite significant mitochondrial membrane depolarization, while HL-60 cell initiated apoptosis and cytochcrome c release after 24 h of treatment. Conclusions: Head and neck cancer cell lines exhibit defects in mitochondrial-membrane-depolarization-induced apoptosis as well as impaired release of cytochrome c despite significant mitochondrial membrane depolarization. Proximal defects in the mitochondrial apoptosis pathway are a feature of HNSCC.(head and neck squamous cell carcinoma)" Note that although the cell lines were depolarized, apoptosis did not occur. So I checked to see if fatty acid metabolism is used by squamous cell carcinoma.
Matti Narkia

Dichloroacetate (DCA) as a potential metabolic-targeting therapy for cancer - British J... - 1 views

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    Dichloroacetate (DCA) as a potential metabolic-targeting therapy for cancer. Michelakis ED, Webster L, Mackey JR. Br J Cancer. 2008 Oct 7;99(7):989-94. Epub 2008 Sep 2. Review. PMID: 18766181 doi:10.1038/sj.bjc.6604554 The unique metabolism of most solid tumours (aerobic glycolysis, i.e., Warburg effect) is not only the basis of diagnosing cancer with metabolic imaging but might also be associated with the resistance to apoptosis that characterises cancer. The glycolytic phenotype in cancer appears to be the common denominator of diverse molecular abnormalities in cancer and may be associated with a (potentially reversible) suppression of mitochondrial function. The generic drug dichloroacetate is an orally available small molecule that, by inhibiting the pyruvate dehydrogenase kinase, increases the flux of pyruvate into the mitochondria, promoting glucose oxidation over glycolysis. This reverses the suppressed mitochondrial apoptosis in cancer and results in suppression of tumour growth in vitro and in vivo. Here, we review the scientific and clinical rationale supporting the rapid translation of this promising metabolic modulator in early-phase cancer clinical trials More than 40 nonrandomised trials of DCA in small cohorts of patients have been reported, but the first two randomised control trials of chronic oral therapy with DCA in congenital mitochondrial diseases were reported in 2006. In the first, a blinded placebo-controlled study was performed with oral DCA administered at 25 mg kg-1 day-1 in 30 patients with MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) (Kaufmann et al, 2006). Most patients enrolled in the DCA arm developed symptomatic peripheral neuropathy, compared with 4 out of 15 in the placebo arm, leading to the termination of the study. Seventeen out of 19 patients had at least partial resolution of peripheral neurological symptoms by 9 months after discontinuation of DCA. This neurotoxicity res
Matti Narkia

Mechanisms of Berberine (Natural Yellow 18)-Induced Mitochondrial Dysfunction: Interact... - 0 views

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    Mechanisms of berberine (natural yellow 18)-induced mitochondrial dysfunction: interaction with the adenine nucleotide translocator. Pereira CV, Machado NG, Oliveira PJ. Toxicol Sci. 2008 Oct;105(2):408-17. Epub 2008 Jul 3. PMID: 18599498 doi: 10.1124/jpet.107.128017 The data from the present work appear to show that berberine also presents some degree of toxicity to "nontumor" systems, which should be carefully understood. ANT inhibition in nontumor cells by berberine would be responsible for a decrease in energy production and could also result in MPT induction. To the best of our knowledge, no full toxicity assessment exists for berberine in humans, although its use in several commercially available supplements suggests that the compound may present a relatively wide safety interval. In fact, a study with patients with congestive heart failure treated with 1.2 g/day of oral berberine revealed low toxicity and resulted into an average plasma concentration of 0.11 mg/l which would translate into 0.3µM (Zeng and Zeng, 1999Go). Repeated cumulative treatments, alternative forms of formulation (e.g., topical application vs. injection) or more importantly, active mitochondrial accumulation due to its positive charge would be expected to increase its concentration in cells into the range of concentrations used in this study. Empirical data from nontraditional medicines plus the use of extensive clinical assays would allow the use of berberine as a promising antimelanoma agent while maintaining its safety for humans. In radial/vertical forms of melanoma, a possible topical application of berberine would also be possible, thus minimizing side effects on other organs. In conclusion, the present work identifies the ANT as an important target for berberine, with clear relevance for its proposed antitumor effects.
Matti Narkia

Berberine inhibits growth, induces G1 arrest and apoptosis in human epidermoid carcinom... - 0 views

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    Berberine inhibits growth, induces G1 arrest and apoptosis in human epidermoid carcinoma A431 cells by regulating Cdki-Cdk-cyclin cascade, disruption of mitochondrial membrane potential and cleavage of caspase 3 and PARP. Mantena SK, Sharma SD, Katiyar SK. Carcinogenesis. 2006 Oct;27(10):2018-27. Epub 2006 Apr 18. PMID: 16621886 doi:10.1093/carcin/bgl043 In the present investigation, we show that berberine, which is present abundantly in Berberis plant species, significantly inhibits the viability, proliferation and induces cell death in human epidermoid carcinoma A431 cells (Figure 1), but this effect was not found in normal human epidermal keratinocytes under the identical conditions, except for a non-significant reduction in cell viability at higher concentrations of berberine (50 and 75 µM) and treatment of cells for a longer period of time (72 h). These data suggested that berberine may be examined as an effective chemotherapeutic agent against non-melanoma skin cancers. In conclusion, our study indicates that berberine inhibits growth, induces G1 arrest and apoptotic cell death of human epidermoid carcinoma A431 cells. We also provide mechanistic evidences that berberine-induced apoptosis in human epidermoid carcinoma cells is mediated through disruption of mitochondrial membrane potential and activation of caspase 3 pathway, although other pathways may have a role and that require further investigation. Moreover, further in vivo studies are required to determine whether berberine could be an effective chemotherapeutic agent for the prevention of non-melanoma skin cancers.
Matti Narkia

The cancer 'TRAP' - 2 views

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    "Worcester, MA - Current research suggests that TNF-receptor associated protein-1 (TRAP-1) may prevent cancer cell death. The related report by Leav et al, "Cytoprotective Mitochondrial Chaperone TRAP-1 as a Novel Molecular Target in Localized and Metastatic Prostate Cancer," appears in the January 2010 issue of the American Journal of Pathology. Prostate cancer cells are often resistant to cell death. Researchers led by Dr. Dario C. Altieri of the University of Massachusetts Medical School, therefore, explored the role of TRAP-1, a protein thought to regulate cell death, in prostate cancer survival. TRAP-1 was highly expressed in both high-grade human prostate cancer lesions and mouse models of prostate cancer, but not in benign or normal prostate tissue. In addition, TRAP-1 overexpression in non-cancer prostate cells inhibited cell death, whereas TRAP-1-deficient prostate cancer cells had enhanced levels of cell death. Moreover, treatment with Gamitrinib, which inhibits TRAP-1, resulted in prostate cancer cell death, but not death of non-cancerous prostate cells. Therefore, targeting TRAP-1 via Gamitrinib treatment may be a viable therapeutic strategy for patients with advanced prostate cancer."
Matti Narkia

Berberine, a natural product, induces G1-phase cell cycle arrest and caspase-3-dependen... - 0 views

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    Berberine, a natural product, induces G1-phase cell cycle arrest and caspase-3-dependent apoptosis in human prostate carcinoma cells. Mantena SK, Sharma SD, Katiyar SK. Mol Cancer Ther. 2006 Feb;5(2):296-308. PMID: 16505103 doi: 10.1158/1535-7163.MCT-05-0448 The effectiveness of berberine in checking the growth of androgen-insensitive, as well as androgen-sensitive, prostate cancer cells without affecting the growth of normal prostate epithelial cells indicates that it may be a promising candidate for prostate cancer therapy. The evaluation of ancient herbal medicines may indicate novel strategies for the treatment of prostate cancer, which remains the leading cause of cancer-related deaths in American men (1). In our present investigation, we show that a naturally occurring isoquinoline alkaloid, berberine, significantly inhibits the proliferation and reduces the viability of DU145 and PC-3 as well as LNCaP cells (Fig. 1), which suggests that berberine may be an effective chemotherapeutic agent against both androgen-sensitive and androgen-insensitive prostate cancer cells. Importantly, we found that berberine did not exhibit toxicity to nonneoplastic human prostate epithelial cells under the conditions used, except for a moderate reduction in cell viability at higher concentrations when cells were treated in vitro for an extended period of time. In conclusion, the results of the present study indicate that berberine inhibits proliferation and induces G1-phase arrest and apoptosis in human prostate cancer cells but not in normal human prostate epithelial cells. In addition, we provide mechanistic evidence that berberine-induced apoptosis in prostate carcinoma cells, particularly hormone-refractory prostate carcinoma cells, is mediated through enhanced expression of Bax, disruption of the mitochondrial membrane potential, and activation of caspase-3.
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