Induction of DT-diaphorase by doxorubicin and combination therapy with mitomycin C in vitro

1995 ◽  
Vol 50 (8) ◽  
pp. 1281-1286 ◽  
Author(s):  
Asher Begleiter ◽  
Marsha K. Leith
Keyword(s):  
Combination Therapy ◽  
Mitomycin C ◽  
Dt Diaphorase

An in Vitro System for Evaluation of Oxidative Stress and the Effects of Antioxidants

1997 ◽  
Vol 25 (3) ◽  
pp. 279-287 ◽  
Author(s):  
Benedikte Brogaard ◽  
Jergen Clausen
Keyword(s):  
Oxidative Stress ◽  
Free Radicals ◽  
Glutathione Peroxidase ◽  
Mitomycin C ◽  
Total Protein ◽  
Human Lymphocytes ◽  
Diaphorase Activity ◽  
Induced Stress ◽  
Dt Diaphorase

Oxidative stress is defined as an imbalance between prooxidants and antioxidants. There is a need for a simple in vitro method for evaluation of the effects of oxidative stress and the effects of antioxidants. In the present study, we used primary cultures of human lymphocytes exposed to either paraquat (PQ) or mitomycin C., two prooxidants generating two different types of free-radicals formed either by P450-reductase or by DT-diaphorase, respectively. The toxicity was measured by estimation of DT-diaphorase and glutathione peroxidase (GSH-Px) activity, and by estimation of the level of malondialdehyde (MDA) as a function of time and increasing doses of the two prooxidants. The enzyme activities were related to both total DNA content and total protein content of cellular homogenate. All estimations were made by exposing human lymphocytes to increasing concentrations (up to 100μM) of the two prooxidants. However, since cellular death occurred at concentrations above 60μM, only data for exposure to concentrations below 70μM are presented. When the enzyme activities were expressed per cellular unit (i.e. per gram DNA) 30μM mitomycin C induced a 30% increase in DT-diaphorase activity. Similarly, a dose-dependent increase (maximum 100% increase) in DT-diaphorase activity was found after exposure to PQ (up to 60μM). Similar data were obtained when data were related to the total protein. Only a minor increase (11%) in GSH-Px activity was induced by 50μM mitomycin C., whereas 20-70μM PQ induced a 41% increase in GSH-Px activity. Both prooxidants induced more than a doubling in the cellular MDA concentration. These findings demonstrate that both DT-diaphorase and GSH-Px are up-regulated during oxidative stress. However, sensitivity to prooxidant-induced stress seems to depend to some extent on the chemistry of the free-radicals generated. Thus, the single-electron pyridium cations generated by PQ seem to be more toxic than the single-electron semi-quinones generated by mitomycin C. The same cellular system was used to evaluate the effects of antioxidants. Quercetin, a naturally occuring flavone, and selenium (sodium selenite), which is an essential part of glutathione peroxidase, were selected. PQ-induced stress and exposure to 5μg/ml quercetin for 4 hours decreased the MDA level in the medium by 11% and in the cells by 33%. PQ-induced stress and exposure to 160μg/l selenium for 18 hours reduced MDA levels similarly, by 19% in the medium and 14% in the cells. Both antioxidants induced a 50% reduction in GSH-Px activity.

Relevance of DT-diaphorase activity to mitomycin C (MMC) efficacy on human cancer cells: Differences in in vitro and in vivo systems

2009 ◽  
Vol 53 (6) ◽  
pp. 1013-1016 ◽  
Author(s):  
Masahiko Nishiyama ◽  
Shuji Saeki ◽  
Kenjiro Aogi ◽  
Naoki Hirabayashi ◽  
Tetsuya Toge
Keyword(s):  
Cancer Cells ◽  
Mitomycin C ◽  
Human Cancer ◽  
Human Cancer Cells ◽  
Diaphorase Activity ◽  
Dt Diaphorase

Neuroprotective and anti-amnestic effects of a combination therapy in a model of photochemical ischemic damage in the prefrontal cortex

2018 ◽  
pp. 39-45
Author(s):  
Ф.М. Шакова ◽  
Т.И. Калинина ◽  
М.В. Гуляев ◽  
Г.А. Романова
Keyword(s):  
Prefrontal Cortex ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Combination Therapy ◽  
Neuroprotective Effect ◽  
Regulatory Protein ◽  
Human Growth ◽  
Neuroprotective Effects ◽  
Nerve Growth

Цель исследования - изучение влияния комбинированной терапии (мутантные молекулы эритропоэтина (EPO) и дипептидный миметик фактора роста нервов ГК-2H) на воспроизведение условного рефлекса пассивного избегания (УРПИ) и объем поражения коры мозга у крыс с двусторонним ишемическим повреждением префронтальной коры. Методика. Мутантные молекулы EPO (MЕРО-TR и MЕPО-Fc) с значительно редуцированной эритропоэтической и выраженной цитопротекторной активностью созданы методом генной инженерии. Используемый миметик фактора роста нервов человека, эндогенного регуляторного белка, в экспериментах in vitro проявлял отчетливые нейропротективные свойства. Двустороннюю фокальную ишемию префронтальной коры головного мозга крыс создавали методом фотохимического тромбоза. Выработку и оценку УРПИ проводили по стандартной методике. Объем повреждения мозга оценивался при помощи МРТ. MEPO-TR и MEPO-Fc (50 мкг/кг) вводили интраназально однократно через 1 ч после фототромбоза, ГК-2Н (1 мг/кг) - внутрибрюшинно через 4 ч после фототромбоза и далее в течение 4 послеоперационных суток. Результаты. Выявлено статистически значимое сохранение выработанного до ишемии УРПИ, а также значимое снижение объема повреждения коры при комплексной терапии. Полученные данные свидетельствуют об антиамнестическом и нейропротекторном эффектах примененной комбинированной терапии, которые наиболее отчетливо выражены в дозах: МEPO-Fc (50 мкг/кг) и ГК-2Н (1 мг/кг). Заключение. Подтвержден нейропротекторный эффект и усиление антиамнестического эффекта при сочетанном применении мутантных производных эритропоэтина - MEPO-TR и MEPO-Fc и дипептидного миметика фактора роста нервов человека ГК-2H. The aim of this study was to investigate the effect of combination therapy, including mutant erythropoietin molecules (EPO) and a dipeptide mimetic of the nerve growth factor, GK-2H, on the conditioned passive avoidance (PA) reflex and the volume of injury induced by bilateral ischemia of the prefrontal cortex in rats. Using the method of genetic engineering the mutant molecules of EPO, MERO-TR and MEPO-Fc, with strongly reduced erythropoietic and pronounced cytoprotective activity were created. The used human nerve growth factor mimetic, an endogenous regulatory protein based on the b-bend of loop 4, which is a dimeric substituted dipeptide of bis- (N-monosuccinyl-glycyl-lysine) hexamethylenediamine, GK-2 human (GK-2H), has proven neuroprotective in in vitro experiments. Methods. Bilateral focal ischemic infarction was modeled in the rat prefrontal cortex by photochemically induced thrombosis. The PA test was performed according to a standard method. Volume of brain injury was estimated using MRI. MEPO-TR, and MEPO-Fc (50 mg/kg, intranasally) were administered once, one hour after the injury. GK-2Н (1 mg/kg, i.p.) was injected four hours after the injury and then for next four days. Results. The study showed that the complex therapy provided statistically significant retention of the PA reflex developed prior to ischemia and a significant decrease in the volume of injury. The anti-amnestic and neuroprotective effects of combination therapy were most pronounced at doses of MEPO-Fc 50 mg/kg and GK-2H 1 mg/kg. Conclusion. This study has confirmed the neuroprotective effect and enhancement of the anti-amnestic effect exerted by the combination of mutant erythropoietin derivatives, MEPO-TR and MEPO-Fc, and the dipeptide mimetic of human growth factor GK-2H.

scholarly journals The effect of platelet-rich fibrin on normal dermal fibroblast proliferation after mitomycin-c treatment: An in vitro study

2021 ◽  
Vol 62 ◽  
pp. 473-476
Author(s):  
Ishandono Dachlan ◽  
Hendy Satrya Kurniawan ◽  
Aditya Wicaksana ◽  
Aditya Rifqi Fauzi ◽  
Firdian Makrufardi ◽  
...  
Keyword(s):  
Mitomycin C ◽  
Dermal Fibroblast ◽  
In Vitro Study ◽  
Vitro Study ◽  
Fibroblast Proliferation ◽  
Platelet Rich Fibrin

scholarly journals ABL001, a Bispecific Antibody Targeting VEGF and DLL4, with Chemotherapy, Synergistically Inhibits Tumor Progression in Xenograft Models

2020 ◽  
Vol 22 (1) ◽  
pp. 241
Author(s):  
Dong-Hoon Yeom ◽  
Yo-Seob Lee ◽  
Ilhwan Ryu ◽  
Sunju Lee ◽  
Byungje Sung ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Tumor Progression ◽  
Cancer Patients ◽  
Bispecific Antibody ◽  
Phase 1 ◽  
Tumor Vessel ◽  
Vegf Inhibitors ◽  
Xenograft Models ◽  
Antibody Targeting

Delta-like-ligand 4 (DLL4) is a promising target to augment the effects of VEGF inhibitors. A simultaneous blockade of VEGF/VEGFR and DLL4/Notch signaling pathways leads to more potent anti-cancer effects by synergistic anti-angiogenic mechanisms in xenograft models. A bispecific antibody targeting VEGF and DLL4 (ABL001/NOV1501/TR009) demonstrates more potent in vitro and in vivo biological activity compared to VEGF or DLL4 targeting monoclonal antibodies alone and is currently being evaluated in a phase 1 clinical study of heavy chemotherapy or targeted therapy pre-treated cancer patients (ClinicalTrials.gov Identifier: NCT03292783). However, the effects of a combination of ABL001 and chemotherapy on tumor vessels and tumors are not known. Hence, the effects of ABL001, with or without paclitaxel and irinotecan were evaluated in human gastric or colon cancer xenograft models. The combination treatment synergistically inhibited tumor progression compared to each monotherapy. More tumor vessel regression and apoptotic tumor cell induction were observed in tumors treated with the combination therapy, which might be due to tumor vessel normalization. Overall, these findings suggest that the combination therapy of ABL001 with paclitaxel or irinotecan would be a better clinical strategy for the treatment of cancer patients.

Emergence of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae in vivo

2019 ◽  
Vol 74 (11) ◽  
pp. 3211-3216 ◽  
Author(s):  
Stephan Göttig ◽  
Denia Frank ◽  
Eleonora Mungo ◽  
Anika Nolte ◽  
Michael Hogardt ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Klebsiella Pneumoniae ◽  
Selection Pressure ◽  
Galleria Mellonella ◽  
Phenotypic Characterization ◽  
Infection Model ◽  
Development Of Resistance ◽  
Time Kill

Abstract Objectives The β-lactam/β-lactamase inhibitor combination ceftazidime/avibactam is active against KPC-producing Enterobacterales. Herein, we present molecular and phenotypic characterization of ceftazidime/avibactam resistance in KPC-3-producing Klebsiella pneumoniae that emerged in vivo and in vitro. Methods Sequence analysis of blaKPC-3 was performed from clinical and in vitro-generated ceftazidime/avibactam-resistant K. pneumoniae isolates. Time–kill kinetics and the Galleria mellonella infection model were applied to evaluate the activity of ceftazidime/avibactam and imipenem alone and in combination. Results The ceftazidime/avibactam-resistant clinical K. pneumoniae isolate revealed the amino acid change D179Y in KPC-3. Sixteen novel mutational changes in KPC-3 among in vitro-selected ceftazidime/avibactam-resistant isolates were described. Time–kill kinetics showed the emergence of a resistant subpopulation under selection pressure with either imipenem or ceftazidime/avibactam. However, combined selection pressure with imipenem plus ceftazidime/avibactam prevented the development of resistance and resulted in bactericidal activity. Concordantly, the G. mellonella infection model revealed that monotherapy with ceftazidime/avibactam is prone to select for resistance in vivo and that combination therapy with imipenem results in significantly better survival. Conclusions Ceftazidime/avibactam is a valuable antibiotic against MDR and carbapenem-resistant Enterobacterales. Based on time–kill kinetics as well as an in vivo infection model we postulate a combination therapy of ceftazidime/avibactam and imipenem as a strategy to prevent the development of ceftazidime/avibactam resistance in KPC-producing Enterobacterales in vivo.

scholarly journals STEM-20. RADIO-SENSITIZING GLIOBLASTOMA CANCER STEM CELLS BY INHIBITION OF FACT

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi237-vi238
Author(s):  
Miranda Montgomery ◽  
Abigail Zalenski ◽  
Amanda Deighen ◽  
Sherry Mortach ◽  
Treg Grubb ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dna Damage ◽  
Cancer Stem Cells ◽  
Combination Therapy ◽  
High Rate ◽  
Primary Role ◽  
Cancer Cell Growth ◽  
Treatment Paradigm

Abstract Glioblastoma (GBM) has a particularly high rate of recurrence with a 5-year overall survival rate of approximately 5%. This is in part due to a sub-population of cancer stem cells (CSC), which are both radioresistant and chemotherapeutically resistant to conventional treatments. Here we investigated CBL0137, a small molecule form of curaxin, in combination with radiotherapy as a means to radiosensitize CSCs. CBL0137 sequesters FACT (facilitates chromatin transcription) complex to chromatin, which leads to activation of p53 and inhibition of NF-κB. This sequestering of FACT results in cytotoxicity especially within tumor cells and prevents FACT from performing its primary role as a histone chaperone, as well as inhibits its part in the DNA damage response pathway. We show that when combined with radiotherapy, CBL0137 administration limited the ability of CSCs to identify and repair damaged DNA. CSCs treated in vitro with CBL0137 and irradiation showed an increased inhibition of cancer cell growth and decreased viability compared to irradiation or drug alone. Combination therapy also showed more DNA damage in the CSCs than with either agent alone. Based on our in vitro evidence for the efficacy of combination therapy to target CSCs, we moved forward to test the treatment in vivo. Using a subcutaneous model, we show that the amount of CD133+ cells (a marker for GMB CSCs) was reduced in irradiation plus CBL0137 compared to either treatment alone. Survival studies demonstrated that irradiation plus CBL0137 compared to irradiation alone or CBL0137 alone increase lifespan. Here we show the ability of CBL0137, in combination with irradiation, to target patient GBM CSCs both in vitro and in vivo. This work establishes a new treatment paradigm for GBM that inclusively targets CSCs and may ultimately reduce tumor recurrence.

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