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1.
J Nutr Biochem ; 122: 109456, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37788725

RESUMO

Diets high in fruit and vegetables are perceived to be beneficial for intestinal homeostasis, in health as well as in the context of inflammatory bowel diseases (IBDs). Recent breakthroughs in the field of immunology have highlighted the importance of the ligand-activated transcription factor aryl hydrocarbon receptor (AhR) as a critical regulator of mucosal immunity, including the intestinal trafficking of CD4+ helper T cells, an immune cell subset implicated in a wide range of homeostatic and pathogenic processes. Specifically, the AhR has been shown to directly regulate the expression of the chemoattractant receptor G Protein-Coupled Receptor 15 (GPR15) on CD4+ T cells. GPR15 is an important gut homing marker whose expression on CD4+ T cells in the peripheral circulation is elevated in patients suffering from ulcerative colitis, raising the possibility that, in this setting, the beneficial effect of a diet rich in fruits and vegetables may be mediated through the modulation of GPR15 expression. To address this, we screened physiologically-relevant polyphenol and glucosinolate metabolites for their ability to affect both AhR activity and GPR15 expression. Our complementary approach and associated findings suggest that polyphenol and glucosinolate metabolites can regulate GPR15 expression on human CD4+ T cells in an AhR-dependent manner.


Assuntos
Linfócitos T CD4-Positivos , Colite Ulcerativa , Humanos , Linfócitos T CD4-Positivos/metabolismo , Glucosinolatos/farmacologia , Receptores de Hidrocarboneto Arílico , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Peptídeos
2.
Support Care Cancer ; 31(9): 524, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37584828

RESUMO

PURPOSE: This systematic review and meta-analysis aimed to evaluate the efficacy of Mepitel film in preventing or treating acute radiation dermatitis (RD) in patients with breast cancer in randomized controlled trials (RCTs). METHODS: Embase, APA PsychInfo, Journals@Ovid Full Text, Ovid MEDLINE, PubMed, and Cochrane Trials were searched until December 12, 2022, to identify RCTs on the use of Mepitel film for preventing or treating acute RD from breast cancer radiotherapy. Per-protocol analysis was used to compare outcomes, calculate pooled effect sizes, odds ratio (OR), and 95% confidence intervals (CI), and to create forest plots using random effects analysis in RevMan 5.4. RESULTS: Three RCTs were included in this review. Mepitel film significantly reduced the incidence of grade 3 RD (OR 0.15 95% CI 0.06, 0.37, p<0.0001) and grade 2 or 3 RD (OR 0.16 95% CI 0.04, 0.65, p=0.01) as scored on either the CTCAE or the RTOG scale. Additionally, Mepitel film significantly reduced RISRAS mean scores assessed by patients and combined researcher and patient (standardized mean difference (SMD) -7.59, 95% CI -14.42, -0.76, p=0.03; SMD -15.36, 95% CI -30.01, -0.71 p=0.04) but not the researcher component of the assessment tool (SMD -17.55, 95% CI -36.94, 1.84, p=0.08). CONCLUSION: Mepitel film reduced the incidence of acute RD and improved patient-reported outcomes with minimal side effects, the main one being itchiness. Future research should assess the feasibility of Mepitel film with respect to specific patient-reported outcomes such as health-related quality of life issues associated with its use.


Assuntos
Neoplasias da Mama , Radiodermite , Humanos , Feminino , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias da Mama/radioterapia , Neoplasias da Mama/complicações , Silicones , Radiodermite/prevenção & controle , Radiodermite/etiologia
3.
Front Oncol ; 12: 857686, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35372069

RESUMO

The ability of cancer cells to adjust their metabolism in response to environmental changes is a well-recognized hallmark of cancer. Diverse cancer and non-cancer cells within tumors compete for metabolic resources. Metabolic demands change frequently during tumor initiation, progression and metastasis, challenging our quest to better understand tumor biology and develop novel therapeutics. Vascularization, physical constraints, immune responses and genetic instability promote tumor evolution resulting in immune evasion, opportunities to breach basement membrane barriers and spread through the circulation and lymphatics. In addition, the unfolded protein response linked to the ubiquitin proteasome system is a key player in addressing stoichiometric imbalances between nuclear and mitochondrially-encoded protein subunits of respiratory complexes, and nuclear-encoded mitochondrial ribosomal protein subunits. While progressive genetic changes, some of which affect metabolic adaptability, contribute to tumorigenesis and metastasis through clonal expansion, epigenetic changes are also important and more dynamic in nature. Understanding the role of stromal and immune cells in the tumor microenvironment in remodeling cancer cell energy metabolism has become an increasingly important area of research. In this perspective, we discuss the adaptations made by cancer cells to balance mitochondrial and glycolytic energy metabolism. We discuss how hypoxia and nutrient limitations affect reductive and oxidative stress through changes in mitochondrial electron transport activity. We propose that integrated responses to cellular stress in cancer cells are central to metabolic flexibility in general and bioenergetic adaptability in particular and are paramount in tumor progression and metastasis.

4.
N Z Med J ; 134(1543): 113-122, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34695082

RESUMO

AIM: The aim of this study was to review and report on radiation therapy injury claims lodged with the Accident Compensation Corporation (ACC) in New Zealand in the last decade. METHODS: ACC's treatment injury database was used to identify injury claims decided between 1 July 2009 and 30 June 2019. The associated structured and unstructured data, including claim lodgement information and medical records, were reviewed. RESULTS: Of 121,168 treatment injuries, only 975 (0.8%) were radiation therapy injury claims, with 519 claims accepted for cover. Most declined claims were considered "ordinary consequences of treatment" rather than treatment injuries. Of the 519 accepted claims, ACC classified 21 as fatal and eight as serious, which indicates a need for lifelong ACC support. Injuries correlated with the age and gender of the most common cancers treated with radiation therapy in New Zealand. More treatment injury claims were submitted and accepted for New Zealand European patients compared with Maori and Pasifika patients. CONCLUSION: Radiation therapy injury claims make up a very small proportion of the total number of ACC treatment injury claims. A better understanding of the claim process may assist injured individuals better by improving appropriate claim lodgement and claim acceptance rates.


Assuntos
Lesões por Radiação/epidemiologia , Radioterapia/efeitos adversos , Lesões Acidentais/economia , Lesões Acidentais/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Compensação e Reparação , Efeitos Psicossociais da Doença , Feminino , Humanos , Lactente , Recém-Nascido , Formulário de Reclamação de Seguro , Masculino , Pessoa de Meia-Idade , Havaiano Nativo ou Outro Ilhéu do Pacífico , Neoplasias/radioterapia , Nova Zelândia/epidemiologia , Lesões por Radiação/economia , Adulto Jovem
5.
J Agric Food Chem ; 69(31): 8625-8633, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34338516

RESUMO

The ligand-activated aryl hydrocarbon receptor (AhR) is an important molecular regulator of immune function, whose activity can be modulated by dietary glucosinolate- and tryptophan-derived metabolites. In contrast, the potential use of polyphenols as dietary regulators of AhR-dependent immunity remains unclear. In this perspective, we discuss how cellular metabolism may alter the net effect of polyphenols on AhR, thus potentially reconciling some of the conflicting observations reported in the literature. We further provide a methodological roadmap, across the fields of immunology, metabolomics, and gut microbial ecology, to explore the potential effects of polyphenol-rich diets on AhR-regulated immune function in humans.


Assuntos
Imunidade , Polifenóis , Receptores de Hidrocarboneto Arílico , Humanos , Ligantes , Polifenóis/farmacologia , Receptores de Hidrocarboneto Arílico/genética , Triptofano
6.
Biochem Biophys Rep ; 24: 100858, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33294636

RESUMO

PURPOSE: Cancer cells rapidly adjust their balance between glycolytic and mitochondrial ATP production in response to changes in their microenvironment and to treatments like radiation and chemotherapy. Reliable, simple, high throughput assays that measure the levels of mitochondrial energy metabolism in cells are useful determinants of treatment effects. Mitochondrial metabolism is routinely determined by measuring the rate of oxygen consumption (OCR). We have previously shown that indirect inhibition of plasma membrane electron transport (PMET) by the mitochondrial uncoupler, FCCP, may also be a reliable measure of mitochondrial energy metabolism. Here, we aimed to validate these earlier findings by exploring the relationship between stimulation of oxygen consumption by FCCP and inhibition of PMET. METHODS: We measured PMET by reduction of the cell impermeable tetrazolium salt WST-1/PMS. We characterised the effect of different growth conditions on the extent of PMET inhibition by FCCP. Next, we compared FCCP-mediated PMET inhibition with FCCP-mediated stimulation of OCR using the Seahorse XF96e flux analyser, in a panel of cancer cell lines. RESULTS: We found a strong inverse correlation between stimulation of OCR and PMET inhibition by FCCP. PMET and OCR were much more severely affected by FCCP in cells that rely on mitochondrial energy production than in cells with a more glycolytic phenotype. CONCLUSION: Indirect inhibition of PMET by FCCP is a reliable, simple and inexpensive high throughput assay to determine the level of mitochondrial energy metabolism in cancer cells.

7.
Front Physiol ; 11: 543962, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33329014

RESUMO

Tumor cells without mitochondrial (mt) DNA (ρ0 cells) are auxotrophic for uridine, and their growth is supported by pyruvate. While ATP synthesis in ρ0 cells relies on glycolysis, they fail to form tumors unless they acquire mitochondria from stromal cells. Mitochondrial acquisition restores respiration that is essential for de novo pyrimidine biosynthesis and for mitochondrial ATP production. The physiological processes that underpin intercellular mitochondrial transfer to tumor cells lacking mtDNA and the metabolic remodeling and restored tumorigenic properties of cells that acquire mitochondria are not well understood. Here, we investigated the changes in mitochondrial and nuclear gene expression that accompany mtDNA deletion and acquisition in metastatic murine 4T1 breast cancer cells. Loss of mitochondrial gene expression in 4T1ρ0 cells was restored in cells recovered from subcutaneous tumors that grew from 4T1ρ0 cells following acquisition of mtDNA from host cells. In contrast, the expression of most nuclear genes that encode respiratory complex subunits and mitochondrial ribosomal subunits was not greatly affected by loss of mtDNA, indicating ineffective mitochondria-to-nucleus communication systems for these nuclear genes. Further, analysis of nuclear genes whose expression was compromised in 4T1ρ0 cells showed that immune- and stress-related genes were the most highly differentially expressed, representing over 70% of those with greater than 16-fold higher expression in 4T1 compared with 4T1ρ0 cells. The monocyte recruiting chemokine, Ccl2, and Psmb8, a subunit of the immunoproteasome that generates MHCI-binding peptides, were the most highly differentially expressed. Early monocyte/macrophage recruitment into the tumor mass was compromised in 4T1ρ0 cells but recovered before mtDNA could be detected. Taken together, our results show that mitochondrial acquisition by tumor cells without mtDNA results in bioenergetic remodeling and re-expression of genes involved in immune function and stress adaptation.

8.
J Med Radiat Sci ; 67(3): 208-216, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32475079

RESUMO

INTRODUCTION: We previously showed that Mepitel Film decreased the severity of acute radiation-induced skin reactions in head and neck cancer patients. In the current study, we compared the effect of Mepitel Film and Biafine cream on skin reaction severity in a larger cohort of head and neck cancer patients. METHODS: A total of 44 head and neck cancer patients were recruited with 39 patients contributing full data sets for analysis. Patients received a dose of 50 Gy in 25 fractions to the bilateral lymph nodes in the neck. Left and right lymph node areas were randomised to either Mepitel Film or Biafine cream, applied prophylactically. Skin reaction severity was measured using Radiation-Induced Skin Reaction Assessment Scale (RISRAS) and expanded Radiation Oncology group (RTOG) grades. Skin dose was measured using gafchromic Film. RESULTS: Skin reaction severity (combined RISRAS score) underneath Mepitel Film was decreased by 30% (P < 0.001) and moist desquamation rates by 41% (P < 0.001). Skin dose underneath Mepitel Film and Biafine cream was similar (P = 0.925) and unlikely to have affected skin reaction severity. The vast majority (80%) of patients preferred Mepitel Film over Biafine cream. Negative aspects of Mepitel Film included poor adherence (11/39) and discomfort (16/39) during hot weather and showering and itchy skin underneath Mepitel Film (12/39). CONCLUSIONS: Mepitel Film was superior to Biafine cream in reducing the severity of acute radiation-induced skin reactions and moist desquamation incidence in our head and neck patient cohort.


Assuntos
Emulsões/farmacologia , Neoplasias de Cabeça e Pescoço/radioterapia , Lipídeos/farmacologia , Lesões por Radiação/tratamento farmacológico , Lesões por Radiação/etiologia , Silicones/farmacologia , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Idoso , Emulsões/uso terapêutico , Feminino , Humanos , Lipídeos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Silicones/uso terapêutico , Creme para a Pele/farmacologia , Creme para a Pele/uso terapêutico
9.
Radiother Oncol ; 149: 117-123, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32413530

RESUMO

PURPOSE: Acute radiation cystitis affects the quality of life of many prostate cancer patients. A previous pilot study suggested that cranberry capsules may decrease some of the symptoms of acute radiation cystitis. Here we further test their effectiveness in a multicentre double blinded placebo-controlled clinical trial. MATERIAL AND METHODS: A total of 108 prostate cancer patients were recruited at three New Zealand hospitals between September 2016 and January 2019. Out of this cohort, 101 patients provided datasets for analysis (51 men on cranberry capsules and 50 men on beetroot-containing placebo capsules). Patients took two capsules each morning during RT and for 2 weeks after completion of RT. Three measures were used to assess cystitis severity: modified RTOG, O'Leary interstitial cystitis scale and a sensitive novel radiation induced cystitis assessment scale (RICAS). Cystitis severity was scored at baseline and weekly thereafter during RT and for two weeks after completion of RT. Radiation protocols were stratified to conventional fractionation or hypo-fractionated radiation therapy (CHHiP) to the prostate or radiation to the prostate bed. RESULTS: Cranberry capsules performed significantly worse than placebo capsules with respect to day time frequency and bladder control, using the more sensitive RICAS scale. No significant difference in cystitis severity was seen between patients receiving hypofractionation and those receiving conventional fractionation to the prostate gland. CONCLUSION: Cranberry capsules were not superior to beetroot-containing placebo capsules in managing radiation cystitis in our prostate patient cohort. RICAS may be a useful tool for measuring radiation cystitis in future studies.


Assuntos
Cistite , Neoplasias da Próstata , Lesões por Radiação , Vaccinium macrocarpon , Cápsulas , Cistite/etiologia , Método Duplo-Cego , Humanos , Masculino , Nova Zelândia , Projetos Piloto , Neoplasias da Próstata/radioterapia , Qualidade de Vida , Lesões por Radiação/terapia , Resultado do Tratamento
10.
Front Oncol ; 8: 344, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30211122

RESUMO

Intercellular communication between cancer cells and other cells in the tumor microenvironment plays a defining role in tumor development. Tumors contain infiltrates of stromal cells and immune cells that can either promote or inhibit tumor growth, depending on the cytokine/chemokine milieu of the tumor microenvironment and their effect on cell activation status. Recent research has shown that stromal cells can also affect tumor growth through the donation of mitochondria to respiration-deficient tumor cells, restoring normal respiration. Nuclear and mitochondrial DNA mutations affecting mitochondrial respiration lead to some level of respiratory incompetence, forcing cells to generate more energy by glycolysis. Highly glycolytic cancer cells tend to be very aggressive and invasive with poor patient prognosis. However, purely glycolytic cancer cells devoid of mitochondrial DNA cannot form tumors unless they acquire mitochondrial DNA from adjacent cells. This perspective article will address this apparent conundrum of highly glycolytic cells and cover aspects of intercellular communication between tumor cells and cells of the microenvironment with particular emphasis on intercellular mitochondrial transfer.

11.
Radiother Oncol ; 127(2): 183-189, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29395288

RESUMO

BACKGROUND AND PURPOSE: A remarkable improvement in patient positioning was observed after the implementation of various process changes aiming to increase the consistency of patient positioning throughout the radiotherapy treatment chain. However, no tool was available to describe these changes over time in a standardised way. This study reports on the feasibility of Statistical Process Control (SPC) to highlight changes in patient positioning accuracy and facilitate correlation of these changes with the underlying process changes. MATERIALS AND METHODS: Metrics were designed to quantify the systematic and random patient deformation as input for the SPC charts. These metrics were based on data obtained from multiple local ROI matches for 191 patients who were treated for head-and-neck cancer during the period 2011-2016. RESULTS: SPC highlighted a significant improvement in patient positioning that coincided with multiple intentional process changes. The observed improvements could be described as a combination of a reduction in outliers and a systematic improvement in the patient positioning accuracy of all patients. CONCLUSION: SPC is able to track changes in the reproducibility of patient positioning in head-and-neck radiation oncology, and distinguish between systematic and random process changes. Identification of process changes underlying these trends requires additional statistical analysis and seems only possible when the changes do not overlap in time.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Posicionamento do Paciente/métodos , Cabeça/efeitos da radiação , Humanos , Pescoço/efeitos da radiação , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Reprodutibilidade dos Testes , Estatística como Assunto
12.
Br J Radiol ; 91(1081): 20170298, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29072852

RESUMO

OBJECTIVE: Mepitel Film significantly decreases acute radiation-induced skin reactions in breast cancer patients. Here we investigated the feasibility of using Mepitel Film in head and neck cancer patients (ACTRN12614000932662). METHODS: Out of a total of 36 head and neck cancer patients from New Zealand (NZ) (n = 24) and China (n = 12) recruited between June 2015 and December 2016, 33 patients complied with protocol. Of these, 11 NZ patients followed a management protocol; 11 NZ patients and 11 Chinese patients followed a prophylactic protocol. An area of the neck receiving a homogenous radiation dose of > 35 Gy was divided into two equal halves; one half was randomized to Film and the other to either Sorbolene cream (NZ) or Biafine cream (China). Skin reaction severity was measured by Radiation Induced Skin Reaction Assessment Scale and expanded Radiation Therapy Oncology Group toxicity criteria. Skin dose was measured by thermoluminescent dosimeters or gafchromic film. RESULTS: Film decreased overall skin reaction severity (combined Radiation Induced Skin Reaction Assessment Scale score) by 29% and moist desquamation rates by 37% in the Chinese cohort and by 27 and 28%, respectively in the NZ cohort. Mepitel Film did not affect head movements but did not adhere well to the skin, particularly in males with heavy beard stubble, and caused itchiness, particularly in Chinese patients. CONCLUSION: Mepitel Film reduced acute radiation-induced skin reactions in our head and neck cancer patients, particularly in patients without heavy stubble. Advances in knowledge: This is the first study to confirm the feasibility of using Mepitel Film in head and neck cancer patients.


Assuntos
Neoplasias de Cabeça e Pescoço/radioterapia , Curativos Oclusivos , Protetores contra Radiação , Radiodermite/prevenção & controle , Silicones , Carcinoma de Células Escamosas/radioterapia , Estudos de Viabilidade , Feminino , Humanos , Masculino
13.
Artigo em Inglês | MEDLINE | ID: mdl-29163365

RESUMO

The ability to rapidly adapt cellular bioenergetic capabilities to meet rapidly changing environmental conditions is mandatory for normal cellular function and for cancer progression. Any loss of this adaptive response has the potential to compromise cellular function and render the cell more susceptible to external stressors such as oxidative stress, radiation, chemotherapeutic drugs, and hypoxia. Mitochondria play a vital role in bioenergetic and biosynthetic pathways and can rapidly adjust to meet the metabolic needs of the cell. Increased demand is met by mitochondrial biogenesis and fusion of individual mitochondria into dynamic networks, whereas a decrease in demand results in the removal of superfluous mitochondria through fission and mitophagy. Effective communication between nucleus and mitochondria (mito-nuclear cross talk), involving the generation of different mitochondrial stress signals as well as the nuclear stress response pathways to deal with these stressors, maintains bioenergetic homeostasis under most conditions. However, when mitochondrial DNA (mtDNA) mutations accumulate and mito-nuclear cross talk falters, mitochondria fail to deliver critical functional outputs. Mutations in mtDNA have been implicated in neuromuscular and neurodegenerative mitochondriopathies and complex diseases such as diabetes, cardiovascular diseases, gastrointestinal disorders, skin disorders, aging, and cancer. In some cases, drastic measures such as acquisition of new mitochondria from donor cells occurs to ensure cell survival. This review starts with a brief discussion of the evolutionary origin of mitochondria and summarizes how mutations in mtDNA lead to mitochondriopathies and other degenerative diseases. Mito-nuclear cross talk, including various stress signals generated by mitochondria and corresponding stress response pathways activated by the nucleus are summarized. We also introduce and discuss a small family of recently discovered hormone-like mitopeptides that modulate body metabolism. Under conditions of severe mitochondrial stress, mitochondria have been shown to traffic between cells, replacing mitochondria in cells with damaged and malfunctional mtDNA. Understanding the processes involved in cellular bioenergetics and metabolic adaptation has the potential to generate new knowledge that will lead to improved treatment of many of the metabolic, degenerative, and age-related inflammatory diseases that characterize modern societies.

14.
PLoS One ; 12(9): e0184250, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28873460

RESUMO

BACKGROUND: Tumour hypoxia limits the effectiveness of radiation therapy. Delivering normobaric or hyperbaric oxygen therapy elevates pO2 in both tumour and normal brain tissue. However, pO2 levels return to baseline within 15 minutes of stopping therapy. AIM: To investigate the effect of perfluorocarbon (PFC) emulsions on hypoxia in subcutaneous and intracranial mouse gliomas and their radiosensitising effect in orthotopic gliomas in mice breathing carbogen (95%O2 and 5%CO2). RESULTS: PFC emulsions completely abrogated hypoxia in both subcutaneous and intracranial GL261 models and conferred a significant survival advantage orthotopically (Mantel Cox: p = 0.048) in carbogen breathing mice injected intravenously (IV) with PFC emulsions before radiation versus mice receiving radiation alone. Carbogen alone decreased hypoxia levels substantially and conferred a smaller but not statistically significant survival advantage over and above radiation alone. CONCLUSION: IV injections of PFC emulsions followed by 1h carbogen breathing, radiosensitises GL261 intracranial tumors.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Dióxido de Carbono/uso terapêutico , Fluorocarbonos/uso terapêutico , Glioma/tratamento farmacológico , Oxigênio/uso terapêutico , Radiossensibilizantes/uso terapêutico , Animais , Neoplasias Encefálicas/patologia , Dióxido de Carbono/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Emulsões , Fluorocarbonos/farmacologia , Glioma/patologia , Camundongos Endogâmicos C57BL , Oxigênio/farmacologia , Radiossensibilizantes/farmacologia , Análise de Sobrevida , Hipóxia Tumoral/efeitos dos fármacos
15.
Antioxidants (Basel) ; 6(3)2017 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-28737676

RESUMO

We have previously shown that exposure to high dose ascorbate causes double stranded breaks (DSBs) and a build-up in S-phase in glioblastoma (GBM) cell lines. Here we investigated whether or not this was due to genotoxic stress as well as metabolic stress generated by exposure to high dose ascorbate, radiation, ascorbate plus radiation and H2O2 in established and primary GBM cell lines. Genotoxic stress was measured as phosphorylation of the variant histone protein, H2AX, 8-oxo-7,8-dihydroguanine (8OH-dG) positive cells and cells with comet tails. Metabolic stress was measured as a decrease in NADH flux, mitochondrial membrane potential (by CMXRos), ATP levels (by ATP luminescence) and mitochondrial superoxide production (by mitoSOX). High dose ascorbate, ascorbate plus radiation, and H2O2 treatments induced both genotoxic and metabolic stress. Exposure to high dose ascorbate blocked DNA synthesis in both DNA damaged and undamaged cell of ascorbate sensitive GBM cell lines. H2O2 treatment blocked DNA synthesis in all cell lines with and without DNA damage. DNA synthesis arrest in cells with damaged DNA is likely due to both genotoxic and metabolic stress. However, arrest in DNA synthesis in cells with undamaged DNA is likely due to oxidative damage to components of the mitochondrial energy metabolism pathway.

16.
Support Care Cancer ; 23(1): 95-102, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24993395

RESUMO

PURPOSE: Acute radiation cystitis, inflammation of the bladder, is a common side effect in men receiving external beam radiation for prostate cancer. Although several treatments provide symptomatic relief, there is no effective treatment to prevent or treat radiation cystitis. Cranberry products have been associated with urinary tract health. This study aimed to determine the effect of highly standardized cranberry capsules (containing 72 mg proanthocyanidins [PACS]) compared with that of placebo capsules on the incidence and severity of radiation cystitis. METHODS: Forty-one men with prostate cancer participated in a double blinded randomized placebo controlled study. Men took one capsule a day at breakfast during treatment and for 2 weeks after treatment completion. Severity of urinary symptoms and the bother these caused were measured using the individual items of the urinary domain of the Modified Expanded Prostate Index Composite (EPIC). RESULTS: The incidence of cystitis was lower in men taking cranberry capsules (65%) compared with those that took placebo capsules (90%) (p = 0.058); severe cystitis was seen in 30% of men in the cranberry arm and 45% in the placebo arm (p = 0.30). Overall, the incidence of pain/burning was significantly lower in the cranberry cohort (p = 0.045). Men on the low hydration regimen who took cranberry had less pain/burning (p = 0.038), stronger urine steam (p = 0.030) and used significantly fewer pads/liners (p = 0.042), which was significantly different from those on the high hydration regimen (p = 0.028). CONCLUSION: Men receiving radiation therapy for prostate cancer may benefit from using cranberry capsules, particularly those on low hydration regimens or with baseline urinary symptoms.


Assuntos
Cistite/prevenção & controle , Preparações de Plantas/uso terapêutico , Lesões por Radiação/prevenção & controle , Radioterapia de Intensidade Modulada/efeitos adversos , Bexiga Urinária/efeitos da radiação , Vaccinium macrocarpon , Idoso , Idoso de 80 Anos ou mais , Cistite/etiologia , Método Duplo-Cego , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Projetos Piloto , Placebos , Neoplasias da Próstata/radioterapia , Resultado do Tratamento , Bexiga Urinária/imunologia , Bexiga Urinária/patologia , Infecções Urinárias/prevenção & controle
17.
Free Radic Biol Med ; 74: 200-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24992837

RESUMO

We previously showed that 5 mM ascorbate radiosensitized early passage radioresistant glioblastoma multiforme (GBM) cells derived from one patient tumor. Here we investigate the sensitivity of a panel of cell lines to 5 mM ascorbate and 6 Gy ionizing radiation, made up of three primary human GBM cells, three GBM cell lines, a human glial cell line, and primary human vascular endothelial cells. The response of different cells lines to ascorbate and/or radiation was determined by measuring viability, colony-forming ability, generation and repair of double-stranded DNA breaks (DSBs), cell cycle progression, antioxidant capacity and generation of reactive oxygen species. Individually, radiation and ascorbate both decreased viability and clonogenicity by inducing DNA damage, but had differential effects on cell cycle progression. Radiation led to G2/M arrest in most cells whereas ascorbate caused accumulation in S phase, which was moderately associated with poor DSB repair. While high dose ascorbate radiosensitized all cell lines in clonogenic assays, the sensitivity to radiation, high dose ascorbate, and combined treatment varied between cell lines. Normal glial cells were similar to GBM cells with respect to free radical scavenging potential and effect of treatment on DNA damage and repair, viability, and clonogenicity. Both GBM cells and normal cells coped equally poorly with oxidative stress caused by radiation and/or high dose ascorbate, dependent primarily on their antioxidant and DSB repair capacity.


Assuntos
Ácido Ascórbico/farmacologia , Quimiorradioterapia/métodos , Células Endoteliais/fisiologia , Glioblastoma/terapia , Neuroglia/fisiologia , Radiossensibilizantes/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular , Ensaio de Unidades Formadoras de Colônias , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/efeitos da radiação , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/efeitos da radiação , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Glioblastoma/patologia , Humanos , Neuroglia/efeitos dos fármacos , Neuroglia/efeitos da radiação , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Radiação Ionizante , Espécies Reativas de Oxigênio/metabolismo
18.
Sci Transl Med ; 6(222): 222fs6, 2014 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-24500402

RESUMO

The addition of high-dose ascorbate to existing anticancer treatment strategies can improve efficacy and decrease toxicity--but not in all patients or with all combination therapies (Ma et al., this issue).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ácido Ascórbico/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Sinergismo Farmacológico , Humanos
19.
Radiother Oncol ; 110(1): 137-43, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24486117

RESUMO

PURPOSE: Safetac-based soft silicone dressings used in a management setting decrease the severity of radiation-induced acute skin reactions but do not affect moist desquamation rates. Here we investigate the prophylactic use of another Safetac product, Mepitel Film, on moist desquamation rates. MATERIAL AND METHODS: A total of 80 breast cancer patients receiving radiation therapy were recruited between October 2012 and April 2013; 78 participants contributed data for analysis. Lateral and medial halves of the skin areas to be irradiated were randomised to Mepitel Film or aqueous cream; skin dose was measured using thermoluminescent dosimeters; skin reaction severity was assessed using RISRAS and RTOG scales. RESULTS: Overall skin reaction severity was reduced by 92% (p<0.0001) in favour of Mepitel Film (RISRAS). All patients developed some form of reaction in cream-treated skin which progressed to moist desquamation in 26% of patients (RTOG grades I: 28%; IIA: 46%; IIB: 18%; III: 8%). Only 44% of patients had a skin reaction under the Film, which did not progress to moist desquamation in any of the patients (RTOG grades I: 36%; IIA: 8%). CONCLUSIONS: Mepitel Film completely prevented moist desquamation and reduced skin reaction severity by 92% when used prophylactically in our cohort.


Assuntos
Neoplasias da Mama/radioterapia , Radiodermite/prevenção & controle , Silicones/administração & dosagem , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Curativos Oclusivos , Pele/efeitos dos fármacos , Pele/efeitos da radiação
20.
J Med Radiat Sci ; 61(2): 119-25, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26229646

RESUMO

Radiation-induced skin reactions are an unavoidable side effect of external beam radiation therapy, particularly in areas prone to friction and excess moisture such as the axilla, head and neck region, perineum and skin folds. Clinical studies investigating interventions for preventing or managing these reactions have largely focussed on formulations with moisturising, anti-inflammatory, anti-microbial and wound healing properties. However, none of these interventions has emerged as a consistent candidate for best practice. Much less emphasis has been placed on evaluating ways to protect the radiation-damaged skin from friction and excess moisture. This mini review analyses the clinical evidence for barrier products that form a protective layer by adhering very closely to the skin folds and do not cause further trauma to the radiation-damaged skin upon removal. A database search identified only two types of barrier products that fitted these criteria and these were tested in two case series and six controlled clinical trials. Friction protection was most effective when the interventions were used from the start of treatment and continued for several weeks after completion of treatment. Soft silicone dressings (Mepilex Lite and Mepitel Film) and Cavilon No Sting Barrier Film, but not Cavilon Moisturizing Barrier Cream, decreased skin reaction severity, most likely due to differences in formulation and skin build-up properties. It seems that prophylactic use of friction protection of areas at risk could be a worthwhile addition to routine care of radiation-damaged skin.

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