RESUMO
Oral mucositis refers to lesions of the oral mucosa observed in patients with cancer being treated with radiation with or without chemotherapy, and can significantly affect quality of life. There is a large unmet medical need to prevent oral mucositis that can occur with radiation either alone or in combination with chemotherapy. We investigated the efficacy of locally administered heparin-binding epidermal growth factor-like growth factor (HB-EGF), a potent epithelial proliferation and migration stimulator of the oral mucosa as a potential therapy to prevent radiation induced oral mucositis. Using a single dose (20 Gy) of radiation to the oral cavity of female C57BL/6 J mice, we evaluated the efficacy of HB-EGF treatment (5 µl of 10 µg/ml) solution. The results show that HB-EGF delivered post radiation, significantly increased the area of epithelial thickness on the tongue (dorsal tongue (42,106 vs 53,493 µm2, p < 0.01), ventral tongue (30,793 vs 39,095 µm2, *p < 0.05)) compared to vehicle control, enhanced new epithelial cell division, and increased the quality and quantity of desmosomes in the oral mucosa measured in the tongue and buccal mucosa. This data provides the proof of concept that local administration of HB-EGF has the potential to be developed as a topical treatment to mitigate oral mucositis following radiation.
Assuntos
Fator de Crescimento Semelhante a EGF de Ligação à Heparina/administração & dosagem , Radioterapia/efeitos adversos , Estomatite/prevenção & controle , Administração Tópica , Animais , Camundongos , Camundongos Endogâmicos C57BL , Estomatite/etiologia , Língua/efeitos da radiaçãoRESUMO
Responses to immuno-oncology agents are often subject to misinterpretation as apparent tumor growth due to immune infiltration leads to the appearance of progressive disease and can result in the discontinuation of effective therapeutic agents. Better statistical strategies to determine experimental outcomes are needed to distinguish between true and pseudoprogression. We applied time-to-event statistical analyses methods that account for study design features and capture the longitudinal and panoramic aspects of pseudoprogression to test superiority of a combination of RRx-001, a novel tumor-associated macrophage polarizing agent in Phase 2, and an anti-PD-L1 antibody in a myeloma preclinical model, comparing to traditional, mean-based mixed effects modeling approaches that did not show statistical significance. Nonparametric p values for the difference of cumulative incidence rates of time to ≥ 50% tumor growth reduction and its associated restricted mean survival times are computed and found to be statistically significant. Kaplan-Meier description of time-to-volume reduction (≥ 50%) coupled with Cox's proportional hazards model follows the data longitudinally and therefore permits an analysis of immune infiltration resolution, making it an improved method for analysis of preclinical experiments with immuno-oncology agents.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Carga Tumoral/efeitos dos fármacos , Progressão da Doença , Humanos , Estimativa de Kaplan-Meier , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Modelos de Riscos ProporcionaisRESUMO
BACKGROUND: RRx-001, a dinitroazetidine derivative, is a novel anticancer agent currently in phase II clinical trials. It mediates immunomodulatory effects either directly through polarization of tumor associated macrophages or indirectly through vascular normalization and increased T-lymphocyte infiltration. With multiple additional mechanisms of action including upregulation of oxidative stress, depletion of GSH and NADPH, anti-angiogenesis and epigenetic modulation, RRx-001 is being studied as a radio- and chemo-sensitizer to resensitize tumors to prior therapy and to prime tumors to respond to radiation, chemotherapy and immunotherapy in combination therapy studies. Here, we identified another mechanism, viral mimicry, which refers to the "unsilencing" of epigenetically repressed viral genes present in the tumor that provokes an immune response and may contribute to the anticancer activity of RRx-001. RESULTS: RRx-001 inhibited the growth of colon cancer cells (HCT 116) and decreased levels of the DNA methyltransferases DNMT1 and DNMT3a in a time and dose-dependent manner. Treatment of HCT 116 cells with 0.5 µM RRx-001 for 24 h significantly increased transcripts of interferon (IFN)-responsive genes and this induction was sustained for up to 4 weeks after transient exposure to RRx-001. ELISA assays showed that RRx-001 increased secretion of type I and III IFNs by HCT 116 cells, and these IFNs were confirmed to be bioactive. Transcription of endogenous retrovirus ERV-Fc2 and LTRs from the ERV-L family (MLT2B4 and MLT1C49) was induced by RRx-001. The induction of ERV-Fc2-env was through demethylation of ERV-Fc2 LTR as determined by methylation-specific polymerase chain reaction and combined bisulfite restriction analysis. Immunofluorescence staining with J2 antibody confirmed induction of double-stranded RNA. CONCLUSIONS: Transient exposure of HCT 116 cells to low-dose RRx-001 induced transcription of silenced retroviral genes present in the cancer cell DNA with subsequent synthesis of IFN in response to this "pseudo-pathogenic" stimulus, mimicking an antiviral defense. RRx-001-mediated IFN induction may have the potential to improve the efficacy of immunotherapies as well as radiotherapy, standard chemotherapies and molecularly targeted agents when used in combination. The striking safety profile of RRx-001 in comparison to other more toxic epigenetic and immunomodulatory agents such as azacitidine makes it a leading candidate for such clinical applications.
Assuntos
Azetidinas/farmacologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/imunologia , Interferons/imunologia , Nitrocompostos/farmacologia , Antineoplásicos/farmacologia , Azacitidina/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/enzimologia , Neoplasias do Colo/genética , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Retrovirus Endógenos/genética , Retrovirus Endógenos/imunologia , Epigênese Genética/efeitos dos fármacos , Células HCT116 , Humanos , Fatores Imunológicos/farmacologia , Interferons/biossíntese , Interferons/genética , Mimetismo Molecular , Transcrição Gênica , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologiaRESUMO
INTRODUCTION: According to Hanahan and Weinberg, cancer manifests as six essential physiologic hallmarks: (1) self-sufficiency in growth signals, (2) insensitivity to growth-inhibitory signals, (3) evasion of programmed cell death, (4) limitless replicative potential, (5) sustained angiogenesis, and (6) invasion and metastasis. As a facilitator of these traits as well as immunosuppression and chemoresistance, the presence of tumor-associated macrophages (TAMs) may serve as the seventh hallmark of cancer. Anticancer agents that successfully reprogram TAMs to target rather than support tumor cells may hold the key to better therapeutic outcomes. Areas covered: This article summarizes the characteristics of the macrophage-stimulating agent RRx-001, a molecular iconoclast, sourced from the aerospace industry, with a particular emphasis on the cell-to-cell transfer mechanism of action (RBCs to TAMs) underlying its antitumor activity as well as its chemo and radioprotective properties, consolidated from various preclinical and clinical studies. Expert opinion: RRx-001 is macrophage-stimulating agent with the potential to synergize with chemotherapy, radiotherapy and immunotherapy while simultaneously protecting normal tissues from their cytotoxic effects. Given the promising indications of activity in multiple tumor types and these normal tissue protective properties, RRx-001 may be used to treat a broad spectrum of malignancies, if it is approved in the future.
Assuntos
Azetidinas/uso terapêutico , Macrófagos/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Nitrocompostos/uso terapêutico , Animais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Azetidinas/efeitos adversos , Azetidinas/farmacologia , Morte Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Macrófagos/metabolismo , Neoplasias/patologia , Nitrocompostos/efeitos adversos , Nitrocompostos/farmacologiaRESUMO
From Adam and Eve, to Darwinism, origin stories attempt to fill in the blanks, connect the dots, and define the turning points that are fundamental to subsequent developments. The purpose of this review is to present the origin story of a one-of-a-kind anticancer agent, RRx-001, which emerged from the aerospace industry as a putative radiosensitizer; not since the dynamite-to-dilator transformation of nitroglycerin in 1878 or the post-World War II explosive-to-elixir conversion of hydralazine, an ingredient in rocket fuel, to an antihypertensive, an antidepressant and an antituberculant, has energetic chemistry been harnessed for therapeutic purposes. This is Part 1 of the radiosensitization story; Parts 2 and 3, which detail the crossover activity of RRx-001 as a chemosensitizer in multiple tumor types and disease states including malaria, hemorrhagic shock and sickle cell anemia, are the subject of future reviews.
Assuntos
Antineoplásicos/química , Azetidinas/química , Neoplasias/radioterapia , Nitrocompostos/química , Radiossensibilizantes/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Azetidinas/farmacologia , Azetidinas/uso terapêutico , Hipóxia Celular/efeitos dos fármacos , Epigênese Genética , Substâncias Explosivas/química , Humanos , Neoplasias/irrigação sanguínea , Nitrocompostos/farmacologia , Nitrocompostos/uso terapêutico , Radiossensibilizantes/farmacologia , Radiossensibilizantes/uso terapêuticoRESUMO
The 'holy grail' in radiation oncology is to improve the outcome of radiation therapy (RT) with a radiosensitizer-a systemic chemical/biochemical agent that additively or synergistically sensitizes tumor cells to radiation in the absence of significant toxicity. Similar to the oxygen effect, in which DNA bases modified by reactive oxygen species prevent repair of the cellular radiation damage, these compounds in general magnify free radical formation, leading to the permanent "fixation" of the resultant chemical change in the DNA structure. The purpose of this review is to present the origin story of the radiosensitizer, RRx-001, which emerged from the aerospace industry. The activity of RRx-001 as a chemosensitizer in multiple tumor types and disease states including malaria, hemorrhagic shock and sickle cell anemia, are the subject of future reviews.
Assuntos
Azetidinas/administração & dosagem , Neoplasias/terapia , Nitrocompostos/administração & dosagem , Radiossensibilizantes/administração & dosagem , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Azetidinas/farmacologia , Humanos , Neoplasias/patologia , Nitrocompostos/farmacologia , Radiossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
RRx-001 is a novel aerospace-derived compound currently under investigation in several ongoing Phase II studies. In a Phase I trial, it demonstrated anti-cancer activity and evidence of resensitization to formerly effective therapies in heavily pre-treated patients with relapsed/refractory solid tumors. RRx-001 generates reactive oxygen and nitrogen species (ROS and RNS) and nitric oxide (NO), elicits changes in intracellular redox status, modulates tumor blood flow, hypoxia and vascular function and triggers apoptosis in cancer cells. We investigated the effect of RRx-001 on the epigenome of SCC VII cancer cells. RRx-001 at 0.5 and 2 µM significantly decreased global DNA methylation, i.e., 5-methylcytosine levels, in SCC VII cells. Consistently, 0.5-5 µM RRx-001 significantly decreased Dnmt1 and Dnmt3a protein expression in a dose- and time-dependent manner. In addition, global methylation profiling identified differentially methylated genes in SCC VII cells treated with 0.5, 2, and 5 µM RRx-001 compared to control cells. Twenty-three target sites were hypomethylated and 22 hypermethylated by >10% in the presence of at least two different concentrations of RRx-001. Moreover, RRx-001 at 2 µM significantly increased global acetylated histone H3 and H4 levels in SCC VII cells after 24 hour treatment, suggesting that RRx-001 regulates global acetylation in cancer cells. These results demonstrate that, in contrast to the traditional "one drug one target" paradigm, RRx-001 has multi(epi)target features, which contribute to its anti-cancer activity and may rationalize the resensitization to previously effective therapies observed in clinical trials and serve as a unifying mechanism for its anticancer activity.
Assuntos
Antineoplásicos/farmacologia , Azetidinas/farmacologia , Carcinoma de Células Escamosas/patologia , Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Nitrocompostos/farmacologia , Acetilação/efeitos dos fármacos , Animais , Western Blotting , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Humanos , Camundongos , Análise de Sequência com Séries de OligonucleotídeosRESUMO
BACKGROUND: Epigenetic alterations have been strongly associated with tumour formation and resistance to chemotherapeutic drugs, and epigenetic modifications are an attractive target in cancer research. RRx-001 is activated by hypoxia and induces the generation of reactive oxygen and nitrogen species that can epigenetically modulate DNA methylation, histone deacetylation, and lysine demethylation. The aim of this phase 1 study was to assess the safety, tolerability, and pharmacokinetics of RRx-001. METHODS: In this open-label, dose-escalation, phase 1 study, we recruited adult patients (aged >18 years) with histologically or cytologically confirmed diagnosis of advanced, malignant, incurable solid tumours from University of California at San Diego, CA, USA, and Sarah Cannon Research Institute, Nashville, TN, USA. Key eligibility criteria included evaluable disease, Eastern Cooperative Group performance status of 2 or less, an estimated life expectancy of at least 12 weeks, adequate laboratory parameters, discontinuation of all previous antineoplastic therapies at least 6 weeks before intervention, and no residual side-effects from previous therapies. Patients were assigned to receive intravenous infusions of RRx-001 at increasing doses (10 mg/m(2), 16·7 mg/m(2), 24·6 mg/m(2), 33 mg/m(2), 55 mg/m(2), and 83 mg/m(2)) either once or twice-weekly for at least 4 weeks, with at least three patients per dose cohort and allowing a 2-week observation period before dose escalation. Samples for safety and pharmacokinetics analysis, including standard chemistry and haematological panels, were taken on each treatment day. The primary objective was to assess safety, tolerability, and dose-limiting toxic effects of RRx-001, to determine single-dose pharmacokinetics, and to identify a recommended dose for phase 2 trials. All analyses were done per protocol. Accrual is complete and follow-up is still on-going. This trial is registered with ClinicalTrials.gov, number NCT01359982. FINDINGS: Between Oct 10, 2011, and March 18, 2013, we enrolled 25 patients and treated six patients in the 10 mg/m(2) cohort, three patients in the 16·7 mg/m(2) cohort, three patients in the 24·6 mg/m(2) cohort, four patients in the 33 mg/m(2) cohort, three patients in the 55 mg/m(2), and six patients in the 83 mg/m(2) cohort. Pain at the injection site, mostly grade 1 and grade 2, was the most common adverse event related to treatment, experienced by 21 (84%) patients. Other common drug-related adverse events included arm swelling or oedema (eight [32%] patients), and vein hardening (seven [28%] patients). No dose-limiting toxicities were observed. Time constraints related to management of infusion pain from RRx-001 resulted in a maximally feasible dose of 83 mg/m(2). Of the 21 evaluable patients, one (5%) patient had a partial response, 14 (67%) patients had stable disease, and six (29%) patients had progressive disease; all responses were across a variety of tumour types. Four patients who had received RRx-001 were subsequently rechallenged with a treatment that they had become refractory to; all four responded to the rechallenge. INTERPRETATION: RRx-001 is a well-tolerated novel compound without clinically significant toxic effects at the tested doses. Preliminary evidence of activity is promising and, on the basis of all findings, a dose of 16·7 mg/m(2) was recommended as the targeted dose for phase 2 trials. FUNDING: EpicentRx (formerly RadioRx).
Assuntos
Azetidinas/administração & dosagem , Epigênese Genética/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Nitrocompostos/administração & dosagem , Adulto , Idoso , Azetidinas/efeitos adversos , Azetidinas/farmacocinética , Relação Dose-Resposta a Droga , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Epigênese Genética/genética , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/patologia , Nitrocompostos/efeitos adversos , Nitrocompostos/farmacocinética , Prognóstico , Resultado do TratamentoRESUMO
Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulatory transcription factor that plays an important role in the antioxidant response pathway against anticancer drug-induced cytotoxic effects. RRx-001 is a new anticancer agent that generates reactive oxygen and nitrogen species, and leads to epigenetic alterations in cancer cells. Here we report the RRx-001 mediated nuclear translocation of Nrf2 and the activation of expression of its downstream enzymes HO-1 and NQO1 in tumor cells. Inhibition of intrinsic Nrf2 expression by Nrf2-specific siRNA increased cell sensitivity to RRx-001. Molecular imaging of tumor cells co-expressing pARE-Firefly luciferase and pCMV-Renilla luciferase-mRFP in vitro and in vivo in mice revealed that RRx-001 significantly increased ARE-FLUC signal in cells in a dose- and time-dependent manner, suggesting that RRx-001 is an effective activator of the Nrf2-ARE signaling pathway. The pre-treatment level of ARE-FLUC signal in cells, reflecting basal activity of Nrf2, negatively correlated with the tumor response to RRx-001. The results support the concept that RRx-001 activates Nrf2-ARE antioxidant signaling pathways in tumor cells. Hence measurement of Nrf2-mediated activation of downstream target genes through ARE signaling may constitute a useful molecular biomarker for the early prediction of response to RRx-001 treatment, and thereby guide therapeutic decision-making.
Assuntos
Antineoplásicos/química , Azetidinas/química , Biomarcadores Tumorais/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Nitrocompostos/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Relação Dose-Resposta a Droga , Epigênese Genética , Regulação da Expressão Gênica , Heme Oxigenase-1/metabolismo , Luciferases/metabolismo , Luminescência , Proteínas Luminescentes/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Nus , NAD(P)H Desidrogenase (Quinona)/metabolismo , Transplante de Neoplasias , Estresse Oxidativo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Proteína Vermelha FluorescenteRESUMO
The endogenous mediator of vasodilation, nitric oxide (NO), has been shown to be a potent radiosensitizer. However, the underlying mode of action for its role as a radiosensitizer - while not entirely understood - is believed to arise from increased tumor blood flow, effects on cellular respiration, on cell signaling, and on the production of reactive oxygen and nitrogen species (RONS), that can act as radiosensitizers in their own right. NO activity is surprisingly long-lived and more potent in comparison to oxygen. Reports of the effects of NO with radiation have often been contradictory leading to confusion about the true radiosensitizing nature of NO. Whether increasing or decreasing tumor blood flow, acting as radiosensitizer or radioprotector, the effects of NO have been controversial. Key to understanding the role of NO as a radiosensitizer is to recognize the importance of biological context. With a very short half-life and potent activity, the local effects of NO need to be carefully considered and understood when using NO as a radiosensitizer. The systemic effects of NO donors can cause extensive side effects, and also affect the local tumor microenvironment, both directly and indirectly. To minimize systemic effects and maximize effects on tumors, agents that deliver NO on demand selectively to tumors using hypoxia as a trigger may be of greater interest as radiosensitizers. Herein we discuss the multiple effects of NO and focus on the clinical molecule RRx-001, a hypoxia-activated NO donor currently being investigated as a radiosensitizer in the clinic.
Assuntos
Antineoplásicos/farmacologia , Azetidinas/farmacologia , Neoplasias/terapia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/farmacologia , Nitrocompostos/farmacologia , Radiossensibilizantes/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Azetidinas/química , Azetidinas/metabolismo , Epigênese Genética , Raios gama/uso terapêutico , Hemoglobinas/química , Hemoglobinas/metabolismo , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/patologia , Hipóxia/terapia , Camundongos , Modelos Moleculares , Neoplasias/irrigação sanguínea , Neoplasias/genética , Neoplasias/metabolismo , Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Nitrocompostos/química , Nitrocompostos/metabolismo , Oxirredução , Oxigênio/metabolismo , Ligação Proteica , Radiossensibilizantes/química , Radiossensibilizantes/metabolismoRESUMO
BACKGROUND: RRx-001 is a novel NO and hypoxia mediated anticancer agent with epigenetic activity. In the first-in-human, Phase I trial, 5/5 patients who progressed on RRx-001 treatment were resensitized to previously refractory therapy, hinting at a generalized resensitization effect. AIMS: A randomized open-label multi-part, multi-center phase II trial of RRx-001 versus regorafenib (ROCKET) has commenced to explore the resensitization and/or 'episensitization' potential in irinotecan refractory tumors and its impact on overall survival. METHODS: Patients with irinotecan-refractory metastatic colorectal cancer with an ECOG PS 0-1 who progressed on oxaliplatin-, and irinotecan-based regimens with or without bevacizumab, cetuximab or panitumumab are randomized 2:1 to receive RRx-001 16.5mg/m2 IV 1x/week or regorafenib 160mg orally 21 of 28 days until progression or unacceptable toxicity followed by treatment with refractory irinotecan-based therapies. RESULTS: To date, 26 patients have been randomized with 18 patients evaluable for resensitization. Post RRx-001 patients demonstrated marked decreases in CEA in 12/13 patients as compared to 5 patients receiving regorafenib who were too systemically unwell to proceed to subsequent treatment. Progression free survival (ongoing) for RRx-001+irinotecan is 4.9 months compared 1.8 months on Regorafenib+irinotecan. CONCLUSION: Early results in the ROCKET study suggest that RRx-001-mediated resensitization to previously refractory therapies may have a generalized effect, independent of KRAS or p53 status. These early results are intriguing, suggesting improved QOL and overall survival over currently approved therapy in the chemotherapy refractory colorectal cancer.
Assuntos
Azetidinas/administração & dosagem , Azetidinas/farmacocinética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Nitrocompostos/administração & dosagem , Nitrocompostos/farmacocinética , Anticorpos Monoclonais/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Bevacizumab/administração & dosagem , Bevacizumab/farmacocinética , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Cetuximab/administração & dosagem , Cetuximab/farmacocinética , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Feminino , Humanos , Irinotecano , Masculino , Metástase Neoplásica , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/farmacocinética , Oxaliplatina , Panitumumabe , Compostos de Fenilureia/administração & dosagem , Compostos de Fenilureia/farmacocinética , Piridinas/administração & dosagem , Piridinas/farmacocinética , Taxa de SobrevidaRESUMO
Selective release of nitric oxide (NO) in tumors could improve the tumor blood flow and drug delivery for chemotherapeutic agents and radiotherapy, thereby increasing the therapeutic index. Glycidyl nitrate (GLYN) is a NO generating small molecule, and has ability to release NO on bioactivation in SCC VII tumor cells. GLYN-induced intracellular NO generation was significantly attenuated by NO scavenger carboxy-PTIO (cPTIO) and NAC. GLYN significantly increases tumor blood flow, but has no effect on the blood flow of normal tissues in tumor-bearing mice. When used with cisplatin, GLYN significantly increased the tumor growth inhibition effect of cisplatin. GLYN also had a modest radiosensitizing effect in vitro and in vivo. GLYN was well tolerated and there were no acute toxicities found at its effective therapeutic doses in preclinical studies. These results suggest that GLYN is a promising new drug for use with chemotherapy and radiotherapy, and provide a compelling rationale for future studies of GLYN and related compounds.
Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Compostos de Epóxi/uso terapêutico , Neoplasias/terapia , Nitratos/uso terapêutico , Doadores de Óxido Nítrico/uso terapêutico , Óxido Nítrico/metabolismo , Radiossensibilizantes/uso terapêutico , Fluxo Sanguíneo Regional/efeitos dos fármacos , Animais , Benzoatos/farmacologia , Linhagem Celular Tumoral , Células HT29 , Humanos , Imidazóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Neoplasias/irrigação sanguínea , Neoplasias/tratamento farmacológico , Neoplasias/radioterapiaRESUMO
Nuclear factor-κB (NF-κB) regulates cellular responses to inflammation and aging, and alterations in NF-κB signaling underlie the pathogenesis of multiple human diseases. Effective clinical therapeutics targeting this pathway remain unavailable. In primary human keratinocytes, we found that hypochlorite (HOCl) reversibly inhibited the expression of CCL2 and SOD2, two NF-κB-dependent genes. In cultured cells, HOCl inhibited the activity of inhibitor of NF-κB kinase (IKK), a key regulator of NF-κB activation, by oxidizing cysteine residues Cys114 and Cys115. In NF-κB reporter mice, topical HOCl reduced LPS-induced NF-κB signaling in skin. We further evaluated topical HOCl use in two mouse models of NF-κB-driven epidermal disease. For mice with acute radiation dermatitis, topical HOCl inhibited the expression of NF-κB-dependent genes, decreased disease severity, and prevented skin ulceration. In aged mice, topical HOCl attenuated age-dependent production of p16INK4a and expression of the DNA repair gene Rad50. Additionally, skin of aged HOCl-treated mice acquired enhanced epidermal thickness and proliferation, comparable to skin in juvenile animals. These data suggest that topical HOCl reduces NF-κB-mediated epidermal pathology in radiation dermatitis and skin aging through IKK modulation and motivate the exploration of HOCl use for clinical aims.
Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Hipocloroso/uso terapêutico , NF-kappa B/fisiologia , Oxidantes/uso terapêutico , Envelhecimento da Pele/efeitos dos fármacos , Dermatopatias/tratamento farmacológico , Transportadores de Cassetes de Ligação de ATP/biossíntese , Transportadores de Cassetes de Ligação de ATP/genética , Hidrolases Anidrido Ácido , Administração Cutânea , Substituição de Aminoácidos , Animais , Células Cultivadas , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/genética , Cisteína/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA , Avaliação Pré-Clínica de Medicamentos , Feminino , Genes Reporter , Humanos , Ácido Hipocloroso/administração & dosagem , Quinase I-kappa B/antagonistas & inibidores , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/genética , Oxidantes/administração & dosagem , Oxirredução , Radiodermite/tratamento farmacológico , Radiodermite/patologia , Dermatopatias/genética , Dermatopatias/metabolismo , Dermatopatias/patologia , Úlcera Cutânea/prevenção & controle , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genética , Transcrição Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
In an effort to develop cancer therapies that maximize cytotoxicity, while minimizing unwanted side effects, we studied a series of novel compounds based on the highly energetic heterocyclic scaffold, dinitroazetidine. In this study, we report the preclinical validation of 1-bromoacetyl-3,3-dinitroazetidine (ABDNAZ), a representative lead compound currently in a phase I clinical trial in patients with cancer. In tumor cell culture, ABDNAZ generated reactive free radicals in a concentration- and time-dependent manner, modulating intracellular redox status and triggering apoptosis. When administered to mice as a single agent, ABDNAZ exhibited greater cytotoxicity than cisplatin or tirapazamine under hypoxic conditions. However, compared with cisplatin, ABDNAZ was better tolerated at submaximal doses, yielding significant tumor growth inhibition in the absence of systemic toxicity. Similarly, when combined with radiation, ABDNAZ accentuated antitumor efficacy along with the therapeutic index. Toxicity studies indicated that ABDNAZ was not myelosuppressive and no dose-limiting toxicity was apparent following daily administration for 14 days. Taken together, our findings offer preclinical proof-of-concept for ABDNAZ as a promising new anticancer agent with a favorable toxicity profile, either as a chemotherapeutic agent or a radiosensitizer.
Assuntos
Antineoplásicos/uso terapêutico , Azetidinas/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Nitrocompostos/farmacologia , Radiossensibilizantes/uso terapêutico , Animais , Antineoplásicos/efeitos adversos , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Terapia Combinada , Avaliação Pré-Clínica de Medicamentos/métodos , Radicais Livres/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C3HRESUMO
Radiation-induced dermatitis is a debilitating clinical problem in cancer patients undergoing cancer radiation therapy. It is also a possible outcome of exposure to high levels of radiation due to accident or hostile activity. We report that activation of aldehyde dehydrogenase 2 (ALDH2) enzymatic activity using the allosteric agonist, Alda-1, significantly reduced 4-hydroxynonenal adducts accumulation, delayed the onset of radiation dermatitis and substantially reduced symptoms in a clinically-relevant model of radiation-induced dermatitis. Importantly, Alda-1 did not radioprotect tumors in mice. Rather, it increased the sensitivity of the tumors to radiation therapy. This is the first report of reactive aldehydes playing a role in the intrinsic radiosensitivity of normal and tumor tissues. Our findings suggest that ALDH2 represents a novel target for the treatment of radiation dermatitis without reducing the benefit of radiotherapy.
Assuntos
Aldeído Desidrogenase/metabolismo , Benzamidas/farmacologia , Benzodioxóis/farmacologia , Radiodermite/tratamento farmacológico , Aldeído-Desidrogenase Mitocondrial , Aldeídos/metabolismo , Animais , Benzamidas/administração & dosagem , Benzodioxóis/administração & dosagem , Ativação Enzimática , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Radiodermite/enzimologia , Pele/enzimologia , Pele/patologiaRESUMO
We previously reported that intetumumab (CNTO 95), a fully human anti-αv integrin monoclonal antibody, is a radiosensitizer in mice with xenograft tumors. Because intetumumab does not cross-react with mouse integrins, but has cross-reactivity with rat integrins, we next studied the potential combined use of radiation therapy and intetumumab in human cancer xenograft models in nude rats to assess effects on both tumor cells and the tumor microenvironment. Nude rats bearing human head and neck cancer and non-small cell lung cancer (NSCLC) xenografts were treated with intetumumab and fractionated local tumor radiotherapy. Effects on tumor growth and metastasis, blood perfusion, oxygenation, and gastrointestinal toxicity were studied. Intetumumab alone had a moderate effect on tumor growth. When combined with fractionated radiation therapy, intetumumab significantly inhibited tumor growth and produced a tumor response rate that was significantly better than with radiation therapy alone. Treatment with intetumumab also significantly reduced lung metastasis in the A549 NSCLC xenograft model. The oxygenation and blood perfusion in xenograft tumors measured by microbubble-enhanced ultrasound imaging were substantially increased after treatment with intetumumab. The combined use of intetumumab and radiation therapy reduced the microvessel density and increased apoptosis in tumor cells and the tumor microenvironment. Toxicity studies showed that treatment with intetumumab did not cause the histopathologic changes in the lungs and did not sensitize the sensitive gastrointestinal epithelium to the effect of radiation therapy. Intetumumab can potentiate the efficacy of fractionated radiation therapy in human cancer xenograft tumors in nude rats without increased toxicity.
Assuntos
Anticorpos Monoclonais/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Radiossensibilizantes/farmacologia , Animais , Anticorpos Monoclonais Humanizados , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/secundário , Linhagem Celular Tumoral , Terapia Combinada , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Integrina alfaV/imunologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Mucosa Intestinal/efeitos da radiação , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/secundário , Masculino , Neoplasias/irrigação sanguínea , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos da radiação , Oxigênio/sangue , Oxigênio/metabolismo , Ratos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Somatostatin analogs are a mainstay of medical therapy in patients with GH producing human pituitary tumors, and it has been suggested that somatostatin analogs may be radioprotective. We utilized GH secreting rat GH3 cells to investigate whether a somatostatin analog may limit the effects of radiation on proliferation and apoptosis in vitro and on tumor growth in vivo. Treatment with lanreotide alone at doses of either 100 or 1000 nM for 48 h reduced clonogenic survival by 5-10%. Radiation alone produced a dose-dependent survival curve with a SF2 of 48-55%, and lanreotide had no effect on this curve. The addition of lanreotide resulted in a 23% increase in the proportion of apoptotic sub-G1 cells following irradiation (P<0.01). In a mouse GH3 tumor xenograft model, lanreotide 10 mg/kg moderately inhibited the growth of GH3 tumors, with a 4x tumor growth delay (TGD) time that ranged from 4.5 to 8.3 days. Fractionated local tumor radiation alone significantly inhibited tumor growth and produced a TGD of 35.1+/-5.7 days for 250 cGy fractions. The combination of lanreotide, either antecedent to or concurrent, with radiation of 250, 200 or 150 cGy/fraction for 5 days inhibited tumor growth and produced the TGD times that were similar to radiation alone (P>0.05). Pretreatment with lanreotide had the most significant radiosensitizing effect. These studies demonstrate that the somatostatin analog lanreotide is not radioprotective in GH3 cells, and further studies are necessary to determine the impact of lanreotide on apoptosis.
Assuntos
Adenoma/patologia , Apoptose/efeitos dos fármacos , Adenoma Hipofisário Secretor de Hormônio do Crescimento/patologia , Peptídeos Cíclicos/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Somatostatina/análogos & derivados , Somatotrofos/patologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta a Droga , Raios gama , Masculino , Camundongos , Camundongos Nus , Doses de Radiação , Protetores contra Radiação/farmacologia , Ratos , Somatostatina/farmacologia , Somatotrofos/efeitos dos fármacos , Somatotrofos/efeitos da radiação , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Selective targeting of up-regulated integrins on tumor cells is a novel antiangiogenesis strategy for treating solid tumors. CNTO 95 is a fully human anti-alpha(v) integrin monoclonal antibody and has shown antitumor activity when used as a single agent in preclinical studies. We previously showed that radiation combined with an integrin alpha(v)beta(3) antagonist cRGD peptide increased the therapeutic efficacy of radiation in preclinical tumor models. We hypothesized that the combination of radiation and CNTO 95 would synergistically enhance the efficacy of radiation therapy. The in vitro studies showed that CNTO 95 radiosensitized and induced apoptosis in M21 cells in vitronectin-coated dishes. In mice bearing established human cancer xenograft tumors, CNTO 95 alone had only a moderate effect on tumor growth. The combined therapy of CNTO 95 and fractionated radiation significantly inhibited tumor growth and produced the longer tumor growth delay time in multiple tumor models. Maintenance dosing of CNTO 95 following irradiation contributed to efficacy and was important for continued inhibition of tumor regrowth. Immunohistochemistry studies showed that the combined use of CNTO 95 and radiation reduced the alpha(v) integrin and vascular endothelial growth factor receptor expression and the microvessel density and increased apoptosis in tumor cells and the tumor microenvironment. CNTO 95 alone and in combination with radiation did not produce any obvious signs of systemic toxicity. These results show that CNTO 95 can potentiate the efficacy of fractionated radiation therapy in a variety of human cancer xenograft tumor types in nude mice. These findings are very promising and may have high translational relevance for the treatment of patients with solid tumors.
Assuntos
Anticorpos Monoclonais/farmacologia , Fracionamento da Dose de Radiação , Integrinas/imunologia , Radioimunoterapia , Animais , Anticorpos Monoclonais Humanizados , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular , Terapia Combinada , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Nus , Neovascularização Patológica , Fatores de TempoRESUMO
The integrins and PI3K/Akt are important mediators of the signal transduction pathways involved in tumor angiogenesis and cell survival after exposure to ionizing radiation. Selective targeting of either integrins or PI3K/Akt can radiosensitize tumors. In this study, we tested the hypothesis that the combined inhibition of integrin alphanubeta3 by cRGD and PI3K/Akt by LY294002 would significantly enhance radiation-induced inhibition of angiogenesis by vascular endothelial cells. Treatment with cRGD inhibited the adhesion and tube formation of human umbilical vein endothelial cells (HUVECs). The inhibitory effect was further increased when cRGD and LY294002 were applied simultaneously. Both radiation and cRGD induced Akt phosphorylation, up-regulated COX2 expression, and increased PGE2 production in HUVECs. Treatment with LY294002 effectively inhibited radiation- and cRGD-induced Akt phosphorylation and up-regulation of COX2 and increased apoptosis of HUVECs. The combined use of cRGD and LY294002 enhanced radiation-induced cell killing. The clonogenic survival of HUVECs was decreased from 34% with 2 Gy radiation to 4% with these agents combined. These results demonstrate that combined use of ionizing radiation, cRGD and LY294002 inhibited multiple signaling transduction pathways involved in tumor angiogenesis and enhanced radiation-induced effects on vascular endothelial cells.
Assuntos
Integrinas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos da radiação , Adesão Celular/efeitos dos fármacos , Adesão Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Cromonas/farmacologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/biossíntese , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/efeitos da radiação , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/efeitos da radiação , Humanos , Proteínas de Membrana/metabolismo , Morfolinas/farmacologia , Neovascularização Fisiológica/efeitos da radiação , Peptídeos Cíclicos/farmacologia , Transdução de Sinais/efeitos dos fármacosRESUMO
PURPOSE: The primary objective was to optimize the combined treatment regimen using arsenic trioxide (ATO) and fractionated radiotherapy for the treatment of malignant glioma. METHODS AND MATERIALS: Nude mice with human glioma xenograft tumors were treated with fractionated local tumor radiation of 250 cGy/fraction/day and 5 mg/kg ATO for 5-10 days. RESULTS: Time course experiments demonstrated that maximal tumor growth delay occurred when ATO was administered between 0 and 4 h after radiation. The combination treatment of ATO and radiation synergistically inhibited tumor growth and produced a tumor growth delay time of 13.2 days, compared with 1.4 days and 6.5 days for ATO and radiation alone (p < 0.01), respectively. The use of concurrent therapy of radiation and ATO initially, followed by ATO as maintenance therapy, was superior to the use of preloading with ATO before combined therapy and produced a tumor growth delay time of 22.7 days as compared with 11.7 days for the ATO preloading regimen (p < 0.01). The maintenance dose of ATO after concurrent therapy was effective and important for continued inhibition of tumor growth. CONCLUSIONS: The combined use of fractionated radiation and ATO is effective for the treatment of glioma xenograft tumors. ATO was most effective when administered 0-4 h after radiation without pretreatment with ATO. These results have important implications for the optimization of treatment regimen using ATO and fractionated radiotherapy for the treatment of brain tumors.