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British Journal of Pharmacology Jan 2014Hypoxia in tumours is known to cause resistance to conventional chemotherapeutic drugs. In contrast, little is known about the effects of hypoxia on targeted anti-cancer...
BACKGROUND AND PURPOSE
Hypoxia in tumours is known to cause resistance to conventional chemotherapeutic drugs. In contrast, little is known about the effects of hypoxia on targeted anti-cancer drugs. This study evaluated the effect of hypoxia on a series of clinically approved tyrosine kinase inhibitors (TKIs).
EXPERIMENTAL APPROACH
The effect of hypoxia (0.1% oxygen) on the activity of conventional cytotoxic drugs (5-fluorouracil, doxorubicin and vinblastine), the hypoxia-activated prodrug tirapazamine and 9 TKIs was determined in a panel of cell lines. Where hypoxia had a marked effect on chemosensitivity, Western blot analysis was conducted to determine the effect of hypoxia on target expression and the effect of TKIs on cell signalling response under aerobic and hypoxic conditions.
KEY RESULTS
Three patterns of chemosensitivity were observed: resistance under hypoxia, equitoxic activity against hypoxic and aerobic cells, and preferential cytotoxicity to hypoxic cells. Significant hypoxia selectivity (independent of HIF1) was observed in the case of dasatinib and this correlated with the ability of dasatinib to inhibit phosphorylation of Src at tyrosine 530. Sorafenib was significantly less effective under hypoxic conditions but resistance did not correlate with hypoxia-induced changes in Raf/MEK/ERK signalling.
CONCLUSIONS AND IMPLICATIONS
Hypoxia influences the activity of TKIs but in contrast to conventional cytotoxic drugs, preferential activity against hypoxic cells can occur. The search for hypoxia-targeted therapies has been long and fruitless and this study suggests that some clinically approved TKIs could preferentially target the hypoxic fraction of some tumour types.
Topics: Antineoplastic Agents; Apoptosis; Cell Hypoxia; Cell Survival; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Humans; Inhibitory Concentration 50; MAP Kinase Kinase Kinases; MCF-7 Cells; Molecular Targeted Therapy; Neoplasms; Oxygen; Phosphorylation; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Signal Transduction; raf Kinases; src-Family Kinases
PubMed: 24117380
DOI: 10.1111/bph.12438 -
Chinese Journal of Cancer Feb 2014Hypoxia, a state of low oxygen, is a common feature of solid tumors and is associated with disease progression as well as resistance to radiotherapy and certain... (Review)
Review
Hypoxia, a state of low oxygen, is a common feature of solid tumors and is associated with disease progression as well as resistance to radiotherapy and certain chemotherapeutic drugs. Hypoxic regions in tumors, therefore, represent attractive targets for cancer therapy. To date, five distinct classes of bioreactive prodrugs have been developed to target hypoxic cells in solid tumors. These hypoxia-activated prodrugs, including nitro compounds, N-oxides, quinones, and metal complexes, generally share a common mechanism of activation whereby they are reduced by intracellular oxidoreductases in an oxygen-sensitive manner to form cytotoxins. Several examples including PR-104, TH-302, and EO9 are currently undergoing phase II and phase III clinical evaluation. In this review, we discuss the nature of tumor hypoxia as a therapeutic target, focusing on the development of bioreductive prodrugs. We also describe the current knowledge of how each prodrug class is activated and detail the clinical progress of leading examples.
Topics: Anthraquinones; Antineoplastic Agents; Aziridines; Cell Hypoxia; Humans; Indolequinones; Molecular Structure; NAD(P)H Dehydrogenase (Quinone); Neoplasms; Nitrogen Mustard Compounds; Nitroimidazoles; Phosphoramide Mustards; Prodrugs; Tirapazamine; Triazines
PubMed: 23845143
DOI: 10.5732/cjc.012.10285 -
BMC Cancer Jul 2013Environment inside even a small tumor is characterized by total (anoxia) or partial oxygen deprivation, (hypoxia). It has been shown that radiotherapy and some...
BACKGROUND
Environment inside even a small tumor is characterized by total (anoxia) or partial oxygen deprivation, (hypoxia). It has been shown that radiotherapy and some conventional chemotherapies may be less effective in hypoxia, and therefore it is important to investigate how different drugs act in different microenvironments. In this study we perform a large screening of the effects of 19 clinically used or experimental chemotherapeutic drugs on five different cell lines in conditions of normoxia, hypoxia and anoxia.
METHODS
A panel of 19 commercially available drugs: 5-fluorouracil, acriflavine, bortezomib, cisplatin, digitoxin, digoxin, docetaxel, doxorubicin, etoposide, gemcitabine, irinotecan, melphalan, mitomycin c, rapamycin, sorafenib, thalidomide, tirapazamine, topotecan and vincristine were tested for cytotoxic activity on the cancer cell lines A2780 (ovarian), ACHN (renal), MCF-7 (breast), H69 (SCLC) and U-937 (lymphoma). Parallel aliquots of the cells were grown at different oxygen pressures and after 72 hours of drug exposure viability was measured with the fluorometric microculture cytotoxicity assay (FMCA).
RESULTS
Sorafenib, irinotecan and docetaxel were in general more effective in an oxygenated environment, while cisplatin, mitomycin c and tirapazamine were more effective in a low oxygen environment. Surprisingly, hypoxia in H69 and MCF-7 cells mostly rendered higher drug sensitivity. In contrast ACHN appeared more sensitive to hypoxia, giving slower proliferating cells, and consequently, was more resistant to most drugs.
CONCLUSIONS
A panel of standard cytotoxic agents was tested against five different human cancer cell lines cultivated at normoxic, hypoxic and anoxic conditions. Results show that impaired chemosensitivity is not universal, in contrast different cell lines behave different and some drugs appear even less effective in normoxia than hypoxia.
Topics: Antineoplastic Agents; Cell Hypoxia; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Humans; Neoplasms
PubMed: 23829203
DOI: 10.1186/1471-2407-13-331 -
International Journal of Hyperthermia :... 2012To evaluate the usefulness of combined treatment with continuous administration of a hypoxic cytotoxin, tirapazamine (TPZ), and mild temperature hyperthermia (MTH) in...
Usefulness of combined treatment with continuous administration of tirapazamine and mild temperature hyperthermia in γ-ray irradiation in terms of local tumour response and lung metastatic potential.
PURPOSE
To evaluate the usefulness of combined treatment with continuous administration of a hypoxic cytotoxin, tirapazamine (TPZ), and mild temperature hyperthermia (MTH) in γ-ray irradiation in terms of local tumour response and lung metastatic potential, referring to the response of intratumour quiescent (Q) cells.
MATERIALS AND METHODS
B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumour-bearing mice then received γ-ray irradiation after a single intraperitoneal injection or 24 h continuous subcutaneous infusion of TPZ, either with or without MTH. Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (= P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, 17 days after irradiation, macroscopic lung metastases were enumerated.
RESULTS
Continuous administration elevated the sensitivity of both the total and Q cells, especially the total cells. MTH raised the sensitivity of Q cells more remarkably in both single and continuous administrations, probably because of more exposure to TPZ in intermediately hypoxic areas derived mainly from chronic hypoxia through MTH. With or without irradiation, TPZ, especially administered continuously and combined with MTH, decreased the number of lung metastases.
CONCLUSION
The combination of continuous long-term administration of TPZ and MTH in γ-ray irradiation was thought to be promising because of its potential to enhance local tumour response and repress lung metastatic potential.
Topics: Animals; Antineoplastic Agents; Combined Modality Therapy; Female; Gamma Rays; Hyperthermia, Induced; Lung Neoplasms; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Tirapazamine; Triazines; Tumor Burden
PubMed: 22946564
DOI: 10.3109/02656736.2012.714517 -
Journal of Medicinal Chemistry Jul 2012Compounds bactericidal against both replicating and nonreplicating Mtb may shorten the length of TB treatment regimens by eliminating infections more rapidly. Screening...
Compounds bactericidal against both replicating and nonreplicating Mtb may shorten the length of TB treatment regimens by eliminating infections more rapidly. Screening of a panel of antimicrobial and anticancer drug classes that are bioreduced into cytotoxic species revealed that 1,2,4-benzotriazine di-N-oxides (BTOs) are potently bactericidal against replicating and nonreplicating Mtb. Medicinal chemistry optimization, guided by semiempirical molecular orbital calculations, identified a new lead compound (20q) from this series with an MIC of 0.31 μg/mL against H37Rv and a cytotoxicity (CC(50)) against Vero cells of 25 μg/mL. 20q also had equivalent potency against a panel of single-drug resistant strains of Mtb and remarkably selective activity for Mtb over a panel of other pathogenic bacterial strains. 20q was also negative in a L5178Y MOLY assay, indicating low potential for genetic toxicity. These data along with measurements of the physiochemical properties and pharmacokinetic profile demonstrate that BTOs have the potential to be developed into a new class of antitubercular drugs.
Topics: Animals; Antitubercular Agents; Chlorocebus aethiops; Drug Discovery; Female; Isomerism; Mice; Mice, Inbred BALB C; Microbial Sensitivity Tests; Molecular Structure; Mycobacterium tuberculosis; Nitrofurans; Nitroimidazoles; Oxides; Quinoxalines; Rats; Tirapazamine; Triazines; Tuberculosis; Vero Cells
PubMed: 22691154
DOI: 10.1021/jm300123s -
Oxidative Medicine and Cellular... 2012Doxorubicin (DOX) causes long-term cardiomyopathy that is dependent on oxidative stress and contractility disorders. Tirapazamine (TP), an experimental adjuvant drug,...
Doxorubicin (DOX) causes long-term cardiomyopathy that is dependent on oxidative stress and contractility disorders. Tirapazamine (TP), an experimental adjuvant drug, passes the same red-ox transformation as DOX. The aim of the study was to evaluate an effect of tirapazamine on oxidative stress, contractile protein level, and cardiomyocyte necrosis in rats administered doxorubicin. Rats were intraperitoneally injected six times once a week with tirapazamine in two doses, 5 (5TP) and 10 mg/kg (10TP), while doxorubicin was administered in dose 1.8 mg/kg (DOX). Subsequent two groups received both drugs simultaneously (5TP+DOX and 10TP+DOX). Tirapazamine reduced heart lipid peroxidation and normalised RyR2 protein level altered by doxorubicin. There were no significant changes in GSH/GSSG ratio, total glutathione, cTnI, AST, and SERCA2 level between DOX and TP+DOX groups. Cardiomyocyte necrosis was observed in groups 10TP and 10TP+DOX.
Topics: Animals; Aspartate Aminotransferases; Biomarkers; Blotting, Western; Calcium; DNA; Doxorubicin; Drug Interactions; Eosinophilia; Male; Myocardium; Myocytes, Cardiac; Oxidation-Reduction; Oxidative Stress; Proteins; Rats; Rats, Wistar; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Tirapazamine; Triazines; Troponin I
PubMed: 22666522
DOI: 10.1155/2012/890826 -
Clinical Cancer Research : An Official... Mar 2012Hepatocyte growth factor (HGF) is a hypoxia-induced secreted protein that binds to cMet and regulates interleukin (IL)-8 expression. We evaluated the role of circulating... (Randomized Controlled Trial)
Randomized Controlled Trial
Prognostic and predictive significance of plasma HGF and IL-8 in a phase III trial of chemoradiation with or without tirapazamine in locoregionally advanced head and neck cancer.
PURPOSE
Hepatocyte growth factor (HGF) is a hypoxia-induced secreted protein that binds to cMet and regulates interleukin (IL)-8 expression. We evaluated the role of circulating HGF and IL-8 as prognostic and predictive factors for efficacy of tirapazamine (TPZ), a hypoxic cell cytotoxin.
EXPERIMENTAL DESIGN
Patients with stages III to IV head and neck cancer were randomized to receive radiotherapy with cisplatin (CIS) or CIS plus TPZ (TPZ/CIS). Eligibility for the substudy included plasma sample availability for HGF and IL-8 assay by ELISA and no major radiation deviations (N = 498). Analyses included adjustment for major prognostic factors. p16(INK4A) staining (human papillomavirus surrogate) was carried out on available tumors. Thirty-nine patients had hypoxia imaging with (18)F-fluoroazomycin arabinoside ((18)FAZA)-positron emission tomography.
RESULTS
Elevated IL-8 level was associated with worse overall survival (OS) irrespective of treatment. There was an interaction between HGF and treatment arm (P = 0.053); elevated HGF was associated with worse OS in the control but not in the TPZ/CIS arm. Similar trends were observed in analyses restricted to p16(INK4A)-negative patients. Four subgroups defined by high and low HGF/IL-8 levels were examined for TPZ effect; the test for interaction with arm was P = 0.099. TPZ/CIS seemed to be beneficial for patients with high HGF and IL-8 but adverse for low HGF and high IL-8. Only HGF correlated with (18)FAZA tumor standard uptake value.
CONCLUSIONS
IL-8 is an independent prognostic factor irrespective of treatment. There is an interaction between HGF and treatment arm. Certain subgroups based on IL-8/HGF levels seemed to do better with TPZ/CIS while others did worse, highlighting the complexity of hypoxia targeting in unselected patients.
Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Carcinoma, Squamous Cell; Chemoradiotherapy; Female; Head and Neck Neoplasms; Hepatocyte Growth Factor; Humans; Interleukin-8; Male; Middle Aged; Positron-Emission Tomography; Tirapazamine; Triazines
PubMed: 22383739
DOI: 10.1158/1078-0432.CCR-11-2094 -
Clinical Cancer Research : An Official... Jan 2012High plasma osteopontin (OPN) levels have been reported to be an adverse prognostic factor in head and neck squamous cell carcinomas (HNSCC), correlate with tumor... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
High plasma osteopontin (OPN) levels have been reported to be an adverse prognostic factor in head and neck squamous cell carcinomas (HNSCC), correlate with tumor hypoxia, and be predictive of benefit from hypoxia-targeted therapy. We sought to confirm the prognostic and predictive significance of OPN in patients treated on a large international trial.
EXPERIMENTAL DESIGN
Patients with stage III/IV HNSCC were randomized to receive definitive radiotherapy concurrently with cisplatin or cisplatin plus the hypoxic cell cytotoxin, tirapazamine (TPZ). Eligibility criteria for this prospective substudy included plasma sample availability for OPN assay by ELISA and absence of major radiation therapy deviations (N = 578). OPN concentrations were analyzed for overall survival (OS) and time to locoregional failure (TTLRF), adjusting for known prognostic factors. Additional analysis was carried out in patients with available tumor p16(INK4A) staining status.
RESULTS
The median OPN level was 544 ng/mL (range: 7-2,640). High OPN levels were not associated with worse OS (relative HR, 1.03 for highest tertile) or TTLRF (relative HR 0.91 for highest tertile). There was no interaction between OPN and treatment arm for OS or TTLRF (P = 0.93 for OS; P = 0.87 for TTLRF). For the highest tertile the 2-year OS was 66% on control arm and 67% on TPZ arm (HR = 1.11, P = 0.67). Similarly for p16(INK4A) negative patients in the highest tertile, the 2-year OS was 61% on control arm and 63% on TPZ arm (HR = 1.05, P = 0.86).
CONCLUSIONS
We found no evidence that high plasma OPN levels were associated with an adverse prognosis in HNSCC, or were predictive of benefit with hypoxia targeting therapy.
Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cisplatin; Cyclin-Dependent Kinase Inhibitor p16; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Head and Neck Neoplasms; Humans; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Recurrence, Local; Neoplasm Staging; Osteopontin; Prospective Studies; Survival Rate; Tirapazamine; Treatment Outcome; Triazines
PubMed: 22096023
DOI: 10.1158/1078-0432.CCR-11-2295 -
Methods and Findings in Experimental... Dec 2010Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from...
Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Trials Knowledge Area of Thomson Reuters Integrity(SM), the drug discovery and development portal, http://www.thomsonreutersintegrity.com. This issue focuses on the following selection of drugs: 17-Hydroxyprogesterone caproate; Abacavir sulfate/lamivudine, Aclidinium bromide, Adalimumab, Adefovir, Alemtuzumab, Alkaline phosphatase, Amlodipine, Apilimod mesylate, Aripiprazole, Axitinib, Azacitidine; Belotecan hydrochloride, Berberine iodide, Bevacizumab, Bortezomib, Bosentan, Bryostatin 1; Calcipotriol/hydrocortisone, Carglumic acid, Certolizumab pegol, Cetuximab, Cinacalcet hydrochloride, Cixutumumab, Coumarin, Custirsen sodium; Darbepoetin alfa, Darifenacin hydrobromide, Darunavir, Dasatinib, Denibulin hydrochloride, Denosumab, Diacetylmorphine, Dulanermin, Duloxetine hydrochloride; Ecogramostim, Enfuvirtide, Entecavir, Enzastaurin hydrochloride, Eplerenone, Escitalopram oxalate, Esomeprazole sodium, Etravirine, Everolimus, Ezetimibe; Fenofibrate/pravastatin sodium, Ferric carboxymaltose, Flavangenol, Fondaparinux sodium; Glutamine, GSK-1024850A; Hepatitis B hyperimmunoglobulin, Hib-MenC, HIV-LIPO-5; Immunoglobulin intravenous (human), Indacaterol maleate, Indibulin, Indium 111 (¹¹¹In) ibritumomab tiuxetan, Influenza A (H1N1) 2009 Monovalent vaccine, Inhalable human insulin, Insulin glulisine; Lapatinib ditosylate, Leucovorin/UFT; Maraviroc, Mecasermin, MMR-V, Morphine hydrochloride, Morphine sulfate/naltrexone hydrochloride, Mycophenolic acid sodium salt; Naproxen/esomeprazole magnesium, Natalizumab; Oncolytic HSV; Paliperidone, PAN-811, Paroxetine, Pegfilgrastim, Peginterferon alfa-2a, Peginterferon alfa-2b/ribavirin, Pegvisomant, Pemetrexed disodium, Pimecrolimus, Posaconazole, Pregabalin; Raltegravir potassium, Ranelic acid distrontium salt, Rasburicase, Rilpivirine hydrochloride; Sertindole, Sivelestat sodium hydrate, Sorafenib, Sumatriptan succinate/naproxen sodium, Sunitinib malate; Tafluprost, Telithromycin, Temsirolimus, Tenofovir disoproxil fumavate, Tenofovir disoproxil fumarate/emtricitabine, Teriparatide, Ticagrelor, Tigecycline, Tipranavir, Tirapazamine, Trimetrexate; Ulipristal acetate; Valganciclovir hydrochloride, Vicriviroc, Vorinostat; Yttrium 90 (90Y) ibritumomab tiuxetan.
Topics: Clinical Trials as Topic; Humans
PubMed: 21225012
DOI: 10.1358/mf.2010.32.10.1573763 -
Basic & Clinical Pharmacology &... Jun 2011Bioreductive drugs can cause retinal toxicity, mediated by extensive apoptosis in the outer retina of rodents and monkeys. In the present study, we have investigated... (Comparative Study)
Comparative Study
Bioreductive drugs can cause retinal toxicity, mediated by extensive apoptosis in the outer retina of rodents and monkeys. In the present study, we have investigated whether or not the novel and promising hypoxia-selective cytotoxin 4-[3-(2-nitro-1-imidazolyl)-propylamino]-7-chloroquinoline hydrochloride (NLCQ-1, NSC 709257) can cause hypoxia-dependent retinal toxicity in BALB/c mice alone or in combination with cyclophosphamide (CPM), one of the anti-cancer agents that acts synergistically with NLCQ-1 against mouse tumours and human xenografts. The bioreductive agent tirapazamine (TPZ) was included for comparison purposes. Retinal damage was quantified by morphometric analysis of histological sections following IP treatment of female BALB/c mice. No retinal toxicity was observed with 10 or 22 mg/kg of NLCQ-1 or 23 mg/kg TPZ alone, whereas statistically significant retinal toxicity was observed with the higher TPZ dose of 52 mg/kg (p < 0.001). Thus, a normalized photoreceptor layer thickness (NPT) value of 0.50 ± 0.04, 0.48 ± 0.03 and 0.33 ± 0.06 was determined for untreated, NLCQ-1 and TPZ-treated mice at the highest dose, respectively. Marginal retinal toxicity was observed with the lower dose of TPZ in combination with CPM.
Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cyclophosphamide; Cytotoxins; Dose-Response Relationship, Drug; Drug Synergism; Female; Humans; Hypoxia; Imidazoles; Mice; Mice, Inbred BALB C; Neoplasms; Quinolines; Retina; Tirapazamine; Triazines
PubMed: 21205223
DOI: 10.1111/j.1742-7843.2010.00667.x