We previously demonstrated that alkyl gallates coupled to triphenylphosphine have a selective and efficient antiproliferative effect by inducing mitochondrial uncoupling in vitro due to the increased mitochondrial transmembrane potential of tumor cells. Therefore, in this work, the in vivo antitumor activities of alkyl gallate triphenylphosphonium derivatives (TPP(+)C8, TPP(+)C10 and TPP(+)C12) were evaluated in a syngeneic murine model of breast cancer. We found that TPP(+)C10 increased the cytosolic ADP/ATP ratio and significantly increased the AMP levels in a concentration-dependent manner in TA3/Ha murine mammary adenocarcinoma cells. Interestingly, TPP(+)C10 induced a decrease in the levels of cellular proliferation markers and promoted caspase-3 activation in tumor-bearing mice. Additionally, TPP(+)C10 inhibited tumor growth in the syngeneic mouse model. Importantly, 30days of intraperitoneal (i.p.) administration of the combination of TPP(+)C10 (10mg/kg/48h) and the antibiotic doxycycline (10mg/kg/24h) completely eliminated the subcutaneous tumor burden in mice (n=6), without any relapses at 60days post-treatment. This enhancement of the individual activities of TPP(+)C10 and doxycycline is due to the uncoupling of oxidative phosphorylation by TPP(+)C10 and the inhibition of mitochondrial biogenesis by doxycycline, as demonstrated by loss of mitochondrial mass and overexpression of PGC1-α as an adaptive response. Moreover, i.p. administration of TPP(+)C10 (10mg/kg/24h) to healthy mice did not produce toxicity or damage in organs important for drug metabolism and excretion, as indicated by hematological, biochemical and histological assessments. These findings suggest that the combination of TPP(+)C10 with doxycycline is a valuable candidate therapy for breast cancer management.

• MeSH
• adenokarcinom farmakoterapie   genetika   metabolismus   patologie   MeSH
• adenosintrifosfát metabolismus   MeSH
• antitumorózní látky farmakologie   MeSH
• apoptóza účinky léků   MeSH
• biogeneze organel MeSH
• časové faktory MeSH
• doxycyklin farmakologie   MeSH
• experimentální nádory mléčných žláz farmakoterapie   genetika   metabolismus   patologie   MeSH
• kaspasa 3 metabolismus   MeSH
• kyselina gallová analogy a deriváty   farmakologie   MeSH
• mitochondrie účinky léků   metabolismus   patologie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory prsu u mužů farmakoterapie   genetika   metabolismus   patologie   MeSH
• organofosforové sloučeniny farmakologie   MeSH
• oxidativní fosforylace účinky léků   MeSH
• proliferace buněk účinky léků   MeSH
• protokoly antitumorózní kombinované chemoterapie farmakologie   MeSH
• signální transdukce účinky léků   MeSH
• spotřeba kyslíku účinky léků   MeSH
• tumor burden účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Pancreatic cancer is one of the hardest-to-treat types of neoplastic diseases. Metformin, a widely prescribed drug against type 2 diabetes mellitus, is being trialed as an agent against pancreatic cancer, although its efficacy is low. With the idea of delivering metformin to its molecular target, the mitochondrial complex I (CI), we tagged the agent with the mitochondrial vector, triphenylphosphonium group. Mitochondrially targeted metformin (MitoMet) was found to kill a panel of pancreatic cancer cells three to four orders of magnitude more efficiently than found for the parental compound. Respiration assessment documented CI as the molecular target for MitoMet, which was corroborated by molecular modeling. MitoMet also efficiently suppressed pancreatic tumors in three mouse models. We propose that the novel mitochondrially targeted agent is clinically highly intriguing, and it has a potential to greatly improve the bleak prospects of patients with pancreatic cancer. Mol Cancer Ther; 15(12); 2875-86. ©2016 AACR.

• MeSH
• antimetabolity antitumorózní chemie   farmakologie   MeSH
• apoptóza účinky léků   MeSH
• cílená molekulární terapie MeSH
• koncentrace vodíkových iontů MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• membránový potenciál mitochondrií MeSH
• metformin chemie   farmakologie   MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• molekulární konformace MeSH
• molekulární modely MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory slinivky břišní farmakoterapie   metabolismus   patologie   MeSH
• proliferace buněk účinky léků   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• respirační komplex I antagonisté a inhibitory   chemie   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• spotřeba kyslíku MeSH
• tumor burden účinky léků   MeSH
• vazba proteinů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Mitochondria play a pivotal role in apoptosis: permeabilization of the outer mitochondrial membrane and the release of pro-apoptotic proteins from the intermembrane space of mitochondria are regarded as the key event in apoptosis induction. Here we demonstrate how non-toxic doses of the mitochondrial Complex II inhibitor thenoyltrifluoroacetone (TTFA), which specifically inhibits the ubiquinone-binding site of succinate dehydrogenase (SDH), synergistically stimulated cell death, induced by harmless doses of cisplatin in a panel of chemoresistant neuroblastoma cell lines. Apoptotic cell death was confirmed by cytochrome c release from the mitochondria, cleavage of poly ADP-ribose polymerase, processing of caspase-3, which is an important executive enzyme in apoptosis, and caspase-3-like activity. Methyl malonate, an inhibitor of the SDHA subunit partially reversed apoptosis stimulated by TTFA in SK-N-BE(2) neuroblastoma cells (NB), indicating that sensitization requires oxidation of succinate. In contrast, in IMR-32 NB cells, the same concentrations of TTFA markedly suppressed cisplatin-induced apoptosis. Comparison of oxygen consumption in cisplatin-resistant SK-N-BE(2) and cisplatin-sensitive IMR-32 cells clearly demonstrated impaired Complex II activity in IMR-32 cells. We also found that in SK-N-BE(2) cells co-treatment with cisplatin and TTFA markedly stimulated formation of reactive oxygen species (ROS), whereas in IMR cells, cisplatin-mediated ROS production was attenuated by TTFA, which explains apoptosis suppression in these cells. Thus, functionally active SDH is a prerequisite for the ROS-mediated sensitization to treatment by TTFA.

• MeSH
• antitumorózní látky farmakologie   MeSH
• apoptóza účinky léků   MeSH
• chemorezistence MeSH
• cílená molekulární terapie * MeSH
• cisplatina farmakologie   MeSH
• kyselina jantarová metabolismus   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• mitochondrie účinky léků   enzymologie   MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny antagonisté a inhibitory   MeSH
• neuroblastom patologie   MeSH
• oxidace-redukce MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• respirační komplex II antagonisté a inhibitory   MeSH
• spotřeba kyslíku účinky léků   MeSH
• superoxidy metabolismus   MeSH
• synergismus léků MeSH
• thenoyltrifluoraceton farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Synthetic caspase inhibitors and particularly broad-spectrum caspase inhibitors can prevent cells from death or at least slow down cell death process and abrogate some apoptotic hallmarks [Kitanaka, C., Kuchino, Y., 1999. Caspase-independent programmed cell death with necrotic morphology. Cell Death and Differentiation 6, 508-515]. However, not all synthetic caspase inhibitors diminish cell death. We have found that the broad-spectrum caspase inhibitor Boc-Asp-CMK induced cell death at micromolar concentrations in human leukaemia cells. Interestingly, low concentrations of Boc-Asp-CMK induced cell death with apoptotic hallmarks. Increasing concentrations of Boc-Asp-CMK led to necrotic cell death. The switch between apoptosis and necrosis seemed to depend upon the degree of inhibition of executioner caspases, including caspase-3/7 with Boc-Asp-CMK. Interestingly, caspase-3 processing was not inhibited even for the highest concentration of Boc-Asp-CMK used. We assume, that toxic properties of Boc-Asp-CMK can be attributed to the chloromethylketone residuum in its molecule, as its analogue Boc-Asp-FMK with fluoromethylketone residuum was more than 13 times less toxic. Our results further indicated that toxicity of Boc-Asp-CMK might arise from its interference with mitochondrial metabolism.

• MeSH
• apoptóza účinky léků   MeSH
• chloromethylketony aminokyselin farmakologie   MeSH
• financování organizované MeSH
• inhibitory enzymů farmakologie   MeSH
• kaspasa 3 antagonisté a inhibitory   metabolismus   MeSH
• lidé MeSH
• proliferace buněk účinky léků   MeSH
• spotřeba kyslíku účinky léků   MeSH
• U937 buňky enzymologie   patologie   MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé MeSH