György Losonczy

Resveratrol induces mitochondrial biogenesis in endothelial cells

Pathways that regulate mitochondrial biogenesis are potential therapeutic targets for the amelioration of endothelial dysfunction and vascular disease. Resveratrol was shown to impact mitochondrial function in skeletal muscle and the liver, but its role in mitochondrial biogenesis in endothelial cells remains poorly defined. The present study determined whether resveratrol induces mitochondrial biogenesis in cultured human coronary arterial endothelial cells (CAECs). In CAECs resveratrol increased mitochondrial mass and mitochondrial DNA content, upregulated protein expression of electron transport chain constituents, and induced mitochondrial biogenesis factors (proliferator-activated receptor-coactivator-1alpha, nuclear respiratory factor-1, mitochondrial transcription factor A). Sirtuin 1 (SIRT1) was induced, and endothelial nitric oxide (NO) synthase (eNOS) was upregulated in a SIRT1-dependent manner. Knockdown of SIRT1 (small interfering RNA) or inhibition of NO synthesis prevented resveratrol-induced mitochondrial biogenesis. In aortas of type 2 diabetic (db/db) mice impaired mitochondrial biogenesis was normalized by chronic resveratrol treatment, showing the in vivo relevance of our findings. Resveratrol increases mitochondrial content in endothelial cells via activating SIRT1. We propose that SIRT1, via a pathway that involves the upregulation of eNOS, induces mitochondrial biogenesis. Resveratrol induced mitochondrial biogenesis in the aortas of type 2 diabetic mice, suggesting the potential for new treatment approaches targeting endothelial mitochondria in metabolic diseases.

Oxidative stress and accelerated vascular aging: Implications for cigarette smoking

Cigarette smoking is the major cause of preventable morbidity and mortality in the United States and constitutes a major risk factor for atherosclerotic vascular disease, including coronary artery disease and stroke. Increasing evidence supports the hypothesis that oxidative stress and inflammation provide the pathophysiological link between cigarette smoking and CAD. Previous studies have shown that cigarette smoke activates leukocytes to release reactive oxygen and nitrogen species (ROS/RNS) and secrete pro-inflammatory cytokines, increases the adherence of monocytes to the endothelium and elicits airway inflammation. Here we present an overview of the direct effects of water-soluble cigarette smoke constituents on endothelial function, vascular ROS production and inflammatory gene expression. The potential pathogenetic role of peroxynitrite formation, and downstream mechanisms including poly(ADP-ribose) polymerase (PARP) activation in cardiovascular complications in smokers are also discussed.

Necitumumab plus gemcitabine and cisplatin versus gemcitabine and cisplatin alone as first-line therapy in patients with stage IV squamous non-small-cell lung cancer (SQUIRE): an open-label, randomised, controlled phase 3 trial

BACKGROUND Necitumumab is a second-generation, recombinant, human immunoglobulin G1 EGFR antibody. In this study, we aimed to compare treatment with necitumumab plus gemcitabine and cisplatin versus gemcitabine and cisplatin alone in patients with previously untreated stage IV squamous non-small-cell lung cancer. METHODS We did this open-label, randomised phase 3 study at 184 investigative sites in 26 countries. Patients aged 18 years or older with histologically or cytologically confirmed stage IV squamous non-small-cell lung cancer, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 and adequate organ function and who had not received previous chemotherapy for their disease were eligible for inclusion. Enrolled patients were randomly assigned centrally 1:1 to a maximum of six 3-week cycles of gemcitabine and cisplastin chemotherapy with or without necitumumab according to a block randomisation scheme (block size of four) by a telephone-based interactive voice response system or interactive web response system. Chemotherapy was gemcitabine 1250 mg/m(2) administered intravenously over 30 min on days 1 and 8 of a 3-week cycle and cisplatin 75 mg/m(2) administered intravenously over 120 min on day 1 of a 3-week cycle. Necitumumab 800 mg, administered intravenously over a minimum of 50 min on days 1 and 8, was continued after the end of chemotherapy until disease progression or intolerable toxic side-effects occurred. Randomisation was stratified by ECOG performance status and geographical region. Neither physicians nor patients were masked to group assignment because of the expected occurrence of acne-like rash--a class effect of EGFR antibodies--that would have unmasked most patients and investigators to treatment. The primary endpoint was overall survival, analysed by intention to treat. We report the final clinical analysis. This study is registered with ClinicalTrials.gov, number NCT00981058. FINDINGS Between Jan 7, 2010, and Feb 22, 2012, we enrolled 1093 patients and randomly assigned them to receive necitumumab plus gemcitabine and cisplatin (n=545) or gemcitabine and cisplatin (n=548). Overall survival was significantly longer in the necitumumab plus gemcitabine and cisplatin group than in the gemcitabine and cisplatin alone group (median 11·5 months [95% CI 10·4-12·6]) vs 9·9 months [8·9-11·1]; stratified hazard ratio 0·84 [95% CI 0·74-0·96; p=0·01]). In the necitumumab plus gemcitabine and cisplatin group, the number of patients with at least one grade 3 or worse adverse event was higher (388 [72%] of 538 patients) than in the gemcitabine and cisplatin group (333 [62%] of 541), as was the incidence of serious adverse events (257 [48%] of 538 patients vs 203 [38%] of 541). More patients in the necitumumab plus gemcitabine and cisplatin group had grade 3-4 hypomagnesaemia (47 [9%] of 538 patients in the necitumumab plus gemcitabine and cisplatin group vs six [1%] of 541 in the gemcitabine and cisplatin group) and grade 3 rash (20 [4%] vs one [<1%]). Including events related to disease progression, adverse events with an outcome of death were reported for 66 (12%) of 538 patients in the necitumumab plus gemcitabine and cisplatin group and 57 (11%) of 541 patients in the gemcitabine and cisplatin group; these were deemed to be related to study drugs in 15 (3%) and ten (2%) patients, respectively. Overall, we found that the safety profile of necitumumab plus gemcitabine and cisplatin was acceptable and in line with expectations. INTERPRETATION Our findings show that the addition of necitumumab to gemcitabine and cisplatin chemotherapy improves overall survival in patients with advanced squamous non-small-cell lung cancer and represents a new first-line treatment option for this disease. FUNDING Eli Lilly and Company.

Exhaled biomarkers in lung cancer

Lung cancer is the leading cause of cancer death. Results of therapeutic interventions are particularly discouraging when the disease is discovered in an advanced stage. Early diagnosis is limited by the fact that the disease usually develops asymptomatically and available screening methods do not fulfil the requirements for reliable discrimination between patients with lung cancer and subjects not suffering from the disease. Breath sampling is completely noninvasive and provides a potentially useful approach to screening lung cancer. Exhaled biomarkers contain both volatile and nonvolatile molecules. The profile of volatile organic compounds is different in patients with lung cancer than in control subjects. In exhaled breath condensate, the proteomic profile of breath from cancer patients differs from that of healthy smokers. We reviewed the scientific evidence demonstrating that a unique chemical signature can be detected in the breath of patients with lung cancer and that the exhaled breath biomarker profile could aid clinical decision making.

Anti-oxidative and anti-inflammatory vasoprotective effects of caloric restriction in aging: Role of circulating factors and SIRT1

Endothelial dysfunction, oxidative stress and inflammation are associated with vascular aging and promote the development of cardiovascular disease. Caloric restriction (CR) mitigates conditions associated with aging, but its effects on vascular dysfunction during aging remain poorly defined. To determine whether CR exerts vasoprotective effects in aging, aortas of ad libitum (AL) fed young and aged and CR-aged F344 rats were compared. Aging in AL-rats was associated with impaired acetylcholine-induced relaxation, vascular oxidative stress and increased NF-kappaB activity. Lifelong CR significantly improved endothelial function, attenuated vascular ROS production, inhibited NF-kappaB activity and down-regulated inflammatory genes. To elucidate the role of circulating factors in mediation of the vasoprotective effects of CR, we determined whether sera obtained from CR animals can confer anti-oxidant and anti-inflammatory effects in cultured coronary arterial endothelial cells (CAECs), mimicking the effects of CR. In CAECs cultured in the presence of AL serum TNFalpha elicited oxidative stress, NF-kappaB activation and inflammatory gene expression. By contrast, treatment of CAECs with CR serum attenuated TNFalpha-induced ROS generation and prevented NF-kappaB activation and induction of inflammatory genes. siRNA knockdown of SIRT1 mitigated the anti-oxidant and anti-inflammatory effects of CR serum. CR exerts anti-oxidant and anti-inflammatory vascular effects, which are likely mediated by circulating factors, in part, via a SIRT1-dependent pathway.

Resveratrol Prevents Monocrotaline-induced Pulmonary Hypertension in Rats

Proliferation of pulmonary arterial smooth muscle cells, endothelial dysfunction, oxidative stress, and inflammation promotes the development of pulmonary hypertension. Resveratrol is a polyphenolic compound that exerts antioxidant and anti-inflammatory protective effects in the systemic circulation, but its effects on pulmonary arteries remain poorly defined. The present study was undertaken to investigate the efficacy of resveratrol to prevent pulmonary hypertension. Rats injected with monocrotaline progressively developed pulmonary hypertension. Resveratrol treatment (25 mg/kg per day, PO, from day 1 postmonocrotaline) attenuated right ventricular systolic pressure and pulmonary arterial remodeling, decreased expression of inflammatory cytokines (tumor necrosis factor-α, interleukin 1β, interleukin 6, and platelet-derived growth factor-α/β), and limited leukocyte infiltration in the lung. Resveratrol also inhibited proliferation of pulmonary arterial smooth muscle cells. Treatment of rats with resveratrol increased expression of endothelial NO synthase, decreased oxidative stress, and improved endothelial function in small pulmonary arteries. Pulmonary hypertension was associated with an upregulation of NAD(P)H oxidase in small pulmonary arteries, which was significantly attenuated by resveratrol treatment. Our studies show that resveratrol exerts anti-inflammatory, antioxidant, and antiproliferative effects in the pulmonary arteries, which may contribute to the prevention of pulmonary hypertension.

Vascular oxidative stress in aging: A homeostatic failure due to dysregulation of NRF2-mediated antioxidant response

There is strong evidence showing that aging is associated with vascular oxidative stress, which has been causally linked to the development of cardiovascular diseases. NF-E2-related factor-2 (Nrf2) is a transcription factor, which is activated by reactive oxygen species in the vasculature of young animals leading to the upregulation of various antioxidant genes. The present study was designed to elucidate age-related changes in the homeostatic role of Nrf2-driven free radical detoxification mechanisms in the vasculature. We found that in the aorta of Fischer 344 × Brown Norway rats, aging results in a progressive increase in O(2)(·-) production, and downregulates protein and mRNA expression of Nrf2, which is associated with a decreased nuclear Nrf2 activity and a decrease in the Nrf2 target genes NAD(P)H:quinone oxidoreductase 1, γ-glutamylcysteine synthetase, and heme oxygenase-1. There was an inverse relationship between vascular expression of Nrf2 target genes and age-related increases in the expression of the NF-κB target genes ICAM-1 and IL-6, which was significant by regression analysis. In cultured aorta segments of young (3 mo old) rats treatment with H(2)O(2) and high glucose significantly increases nuclear translocation of Nrf2 and upregulates the expression of Nrf2 target genes. In contrast, in cultured aorta segments of aged (24 mo old) rats, the induction of Nrf2-dependent responses by H(2)O(2) and high glucose are blunted. High glucose-induced vascular oxidative stress was more severe in aortas of aged rats, as shown by the significantly increased H(2)O(2) production in these vessels, compared with responses obtained in aortas from young rats. Moreover, we found that aging progressively increases vascular sensitivity to the proapoptotic effects of H(2)O(2) and high glucose treatments. Taken together, aging is associated with Nrf2 dysfunction in the vasculature, which likely exacerbates age-related cellular oxidative stress and increases sensitivity of aged vessels to oxidative stress-induced cellular damage.

Adaptive induction of NF-E2-related factor-2-driven antioxidant genes in endothelial cells in response to hyperglycemia

Hyperglycemia in diabetes mellitus promotes oxidative stress in endothelial cells, which contributes to development of cardiovascular diseases. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a transcription factor activated by oxidative stress that regulates expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes. This study was designed to elucidate the homeostatic role of adaptive induction of Nrf2-driven free radical detoxification mechanisms in endothelial protection under diabetic conditions. Using a Nrf2/antioxidant response element (ARE)-driven luciferase reporter gene assay we found that in a cultured coronary arterial endothelial cell model hyperglycemia (10-30 mmol/l glucose) significantly increases transcriptional activity of Nrf2 and upregulates the expression of the Nrf2 target genes NQO1, GCLC, and HMOX1. These effects of high glucose were significantly attenuated by small interfering RNA (siRNA) downregulation of Nrf2 or overexpression of Keap-1, which inactivates Nrf2. High-glucose-induced upregulation of NQO1, GCLC, and HMOX1 was also prevented by pretreatment with polyethylene glycol (PEG)-catalase or N-acetylcysteine, whereas administration of H(2)O(2) mimicked the effect of high glucose. To test the effects of metabolic stress in vivo, Nrf2(+/+) and Nrf2(-/-) mice were fed a high-fat diet (HFD). HFD elicited significant increases in mRNA expression of Gclc and Hmox1 in aortas of Nrf2(+/+) mice, but not Nrf2(-/-) mice, compared with respective standard diet-fed control mice. Additionally, HFD-induced increases in vascular ROS levels were significantly greater in Nrf2(-/-) than Nrf2(+/+) mice. HFD-induced endothelial dysfunction was more severe in Nrf2(-/-) mice, as shown by the significantly diminished acetylcholine-induced relaxation of aorta of these animals compared with HFD-fed Nrf2(+/+) mice. Our results suggest that adaptive activation of the Nrf2/ARE pathway confers endothelial protection under diabetic conditions.

Disruption of Nrf2 Signaling Impairs Angiogenic Capacity of Endothelial Cells: Implications for Microvascular Aging

The redox-sensitive transcription factor NF-E2-related factor 2 (Nrf2) plays a key role in preserving a healthy endothelial phenotype and maintaining the functional integrity of the vasculature. Previous studies demonstrated that aging is associated with Nrf2 dysfunction in endothelial cells, which alters redox signaling and likely promotes the development of large vessel disease. Much less is known about the consequences of Nrf2 dysfunction at the level of the microcirculation. To test the hypothesis that Nrf2 regulates angiogenic capacity of endothelial cells, we determined whether disruption of Nrf2 signaling (by siRNA knockdown of Nrf2 and overexpression of Keap1, the cytosolic repressor of Nrf2) impairs angiogenic processes in cultured human coronary arterial endothelial cells stimulated with vascular endothelial growth factor and insulin-like growth factor-1. In the absence of functional Nrf2, coronary arterial endothelial cells exhibited impaired proliferation and adhesion to vitronectin and collagen. Disruption of Nrf2 signaling also reduced cellular migration (measured by a wound-healing assay using electric cell-substrate impedance sensing technology) and impaired the ability of coronary arterial endothelial cells to form capillary-like structures. Collectively, we find that Nrf2 is essential for normal endothelial angiogenic processes, suggesting that Nrf2 dysfunction may be a potential mechanism underlying impaired angiogenesis and microvascular rarefaction in aging.

TG4010 immunotherapy and first-line chemotherapy for advanced non-small-cell lung cancer (TIME): results from the phase 2b part of a randomised, double-blind, placebo-controlled, phase 2b/3 trial.

BACKGROUND MUC1 is a tumour-associated antigen expressed by many solid tumours, including non-small-cell lung cancer. TG4010 is a modified vaccinia Ankara expressing MUC1 and interleukin 2. In a previous study, TG4010 combined with chemotherapy showed activity in non-small-cell lung cancer and the baseline value of CD16, CD56, CD69 triple-positive activated lymphocytes (TrPAL) was shown to be potentially predictive of TG4010 efficacy. In this phase 2b part of the phase 2b/3 TIME trial, we further assess TG4010 in combination with first-line chemotherapy and use of the TrPAL biomarker in this setting. METHODS In this phase 2b part of a randomised, double-blind, placebo-controlled, phase 2b/3 trial, we recruited previously untreated patients aged 18 years or older with stage IV non-small-cell lung cancer without a known activating EGFR mutation and with MUC1 expression in at least 50% of tumoural cells. Patients were randomly allocated (1:1) by an external service provider to subcutaneous injections of 10(8) plaque-forming units of TG4010 or placebo from the beginning of chemotherapy every week for 6 weeks and then every 3 weeks up to progression, discontinuation for any reason, or toxic effects, stratified according to baseline value of TrPAL (≤ or > the upper limit of normal [ULN]) and, in addition, a dynamic minimisation procedure was used, taking into account chemotherapy regimen, histology, addition or not of bevacizumab, performance status, and centre. Patients, site staff, monitors, the study funder, data managers, and the statistician were masked to treatment identity. The primary endpoint was progression-free survival, assessed every 6 weeks, to validate the predictive value of the TrPAL biomarker. If patients with TrPAL values of less than or equal to the ULN had a Bayesian probability of more than 95% that the true hazard ratio (HR) for progression-free survival was less than 1, and if those with TrPAL values of greater than the ULN had a probability of more than 80% that the true HR for progression-free survival was more than 1, the TrPAL biomarker would be validated. We did primary analyses in the intention-to-treat population and safety analyses in those who had received at least one dose of study drug and had at least one valid post-baseline safety assessment. Monitors, site staff, and patients are still masked to treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT01383148. FINDINGS Between April 10, 2012, and Sept 12, 2014, we randomly allocated 222 patients (TG4010 and chemotherapy 111 [50%]; placebo and chemotherapy 111 [50%]). In the whole population, median progression-free survival was 5·9 months (95% CI 5·4-6·7) in the TG4010 group and 5·1 months (4·2-5·9) in the placebo group (HR 0·74 [95% CI 0·55-0·98]; one-sided p=0·019). In patients with TrPAL values of less than or equal to the ULN, the HR for progression-free survival was 0·75 (0·54-1·03); the posterior probability of the HR being less than 1 was 98·4%, and thus the primary endpoint was met. In patients with TrPAL values of greater than the ULN, the HR for progression-free survival was 0·77 (0·42-1·40); the posterior probability of the HR being greater than 1 was 31·3%, and the primary endpoint was not met. We noted grade 1-2 injection-site reactions in 36 (33%) of 110 patients in the TG4010 group versus four (4%) of 107 patients in the placebo group. We noted no grade 3 or 4 nor serious adverse events deemed to be related to TG4010 only. Four (4%) patients presented grade 3 or 4 adverse events related to TG4010 and other study treatments (chemotherapy or bevacizumab) versus 11 (10%) in the placebo group. No serious adverse event was related to the combination of TG4010 with other study treatments. The most frequent severe adverse events were neutropenia (grade 3 29 [26%], grade 4 13 [12%] in the TG4010 group vs grade 3 22 [21%], grade 4 11 [10%] in the placebo group), anaemia (grade 3 12 [11%] vs grade 3 16 [15%]), and fatigue (grade 3 12 [11%], grade 5 one [1%] vs grade 3 13 [12%]; no grade 4 events). INTERPRETATION TG4010 plus chemotherapy seems to improve progression-free survival relative to placebo plus chemotherapy. These data support the clinical value of the TrPAL biomarker in this clinical setting; because the primary endpoint was met, the trial is to continue into the phase 3 part. FUNDING Transgene, Avancées Diagnostiques pour de Nouvelles Approches Thérapeutiques (ADNA), and OSEO.