Farastuk Bozorgmehr

Glyoxalase-1 prevents mitochondrial protein modification and enhances lifespan in Caenorhabditis elegans

Studies of mutations affecting lifespan in Caenorhabditis elegans show that mitochondrial generation of reactive oxygen species (ROS) plays a major causative role in organismal aging. Here, we describe a novel mechanism for regulating mitochondrial ROS production and lifespan in C. elegans: progressive mitochondrial protein modification by the glycolysis‐derived dicarbonyl metabolite methylglyoxal (MG). We demonstrate that the activity of glyoxalase‐1, an enzyme detoxifying MG, is markedly reduced with age despite unchanged levels of glyoxalase‐1 mRNA. The decrease in enzymatic activity promotes accumulation of MG‐derived adducts and oxidative stress markers, which cause further inhibition of glyoxalase‐1 expression. Over‐expression of the C. elegans glyoxalase‐1 orthologue CeGly decreases MG modifications of mitochondrial proteins and mitochondrial ROS production, and prolongs C. elegans lifespan. In contrast, knock‐down of CeGly increases MG modifications of mitochondrial proteins and mitochondrial ROS production, and decreases C. elegans lifespan.

C. elegans as Model for the Study of High Glucose– Mediated Life Span Reduction

OBJECTIVE Establishing Caenorhabditis elegans as a model for glucose toxicity–mediated life span reduction. RESEARCH DESIGN AND METHODS C. elegans were maintained to achieve glucose concentrations resembling the hyperglycemic conditions in diabetic patients. The effects of high glucose on life span, glyoxalase-1 activity, advanced glycation end products (AGEs), and reactive oxygen species (ROS) formation and on mitochondrial function were studied. RESULTS High glucose conditions reduced mean life span from 18.5 ± 0.4 to 16.5 ± 0.6 days and maximum life span from 25.9 ± 0.4 to 23.2 ± 0.4 days, independent of glucose effects on cuticle or bacterial metabolization of glucose. The formation of methylglyoxal-modified mitochondrial proteins and ROS was significantly increased by high glucose conditions and reduced by mitochondrial uncoupling and complex IIIQo inhibition. Overexpression of the methylglyoxal–detoxifying enzyme glyoxalase-1 attenuated the life-shortening effect of glucose by reducing AGE accumulation (by 65%) and ROS formation (by 50%) and restored mean (16.5 ± 0.6 to 20.6 ± 0.4 days) and maximum life span (23.2 ± 0.4 to 27.7 ± 2.3 days). In contrast, inhibition of glyoxalase-1 by RNAi further reduced mean (16.5 ± 0.6 to 13.9 ± 0.7 days) and maximum life span (23.2 ± 0.4 to 20.3 ± 1.1 days). The life span reduction by glyoxalase-1 inhibition was independent from the insulin signaling pathway because high glucose conditions also affected daf-2 knockdown animals in a similar manner. CONCLUSIONS C. elegans is a suitable model organism to study glucose toxicity, in which high glucose conditions limit the life span by increasing ROS formation and AGE modification of mitochondrial proteins in a daf-2 independent manner. Most importantly, glucose toxicity can be prevented by improving glyoxalase-1–dependent methylglyoxal detoxification or preventing mitochondrial dysfunction.

Apurinic/apyrimidinic endonuclease 1, p53, and thioredoxin are linked in control of aging in C. elegans.

Deletions in mitochondrial DNA (mtDNA) accumulate during aging. Expression of the Caenorhabditis elegans apurinic/apyrimidinic endonuclease 1 (APE1) ortholog exo‐3, involved in DNA repair, is reduced by 45% (P < 0.05) during aging of C. elegans. Suppression of exo‐3 by treatment with RNAi resulted in a threefold increase in mtDNA deletions (P < 0.05), twofold enhanced generation of reactive oxygen species (ROS) (P < 0.01), distortion of the structural integrity of the nervous system, reduction of head motility by 43% (P < 0.01) and whole animal motility by 38% (P < 0.05). Suppression of exo‐3 significantly reduced life span: mean life span decreased from 18.5 ± 0.4 to 15.4 ± 0.1 days (P < 0.001) and maximum life span from 25.9 ± 0.4 to 23.2 ± 0.1 days (P = 0.001). Additional treatment of exo‐3‐suppressed animals with a mitochondrial uncoupler decreased ROS levels, reduced neuronal damage, and increased motility and life span. Additional suppression of the C. elegans p53 ortholog cep‐1 in exo‐3 RNAi‐treated animals similarly decreased ROS levels, preserved neuronal integrity, and increased motility and life span. In wild‐type animals, suppression of cep‐1, involved in downregulation of exo‐3, increased expression of exo‐3 without a significant effect on ROS levels, preserved neuronal integrity, and increased motility and life span. Suppression of the C. elegans thioredoxin orthologs trx‐1 and trx‐2, involved in the redox chaperone activity of exo‐3, overrides the protective effect of cep‐1 RNAi treatment on neuronal integrity, neuronal function, mean and maximum life span. These results show that APE1/EXO‐3, p53/CEP‐1, and thioredoxin affect each other and that these interactions determine aging as well as neuronal structure and function.

Retrospective Study in 23 Patients of the Self-Expanding Sinus-XL Stent for Treatment of Malignant Superior Vena Cava Obstruction Caused by Non–Small Cell Lung Cancer

PURPOSE To evaluate retrospectively the self-expanding nitinol Sinus-XL stent (OptiMed, Ettlingen, Germany) for the treatment of superior vena cava (SVC) obstruction caused by non-small cell lung cancer (NSCLC). MATERIALS AND METHODS Between October 2009 and December 2012, 23 patients (7 women and 16 men; age, 62.5 y ± 8.5) with stage IIIA (1 patient), IIIB (4 patients) or IV (18 patients) NSCLC and acute SVC obstruction were scheduled for urgent stent implantation. The primary study endpoints were technical success (defined as accurate stent placement with complete coverage of the obstructed SVC), residual stenosis < 30%, and clinical efficacy. Complications were assessed as a secondary study endpoint. RESULTS There were 26 stents implanted in 23 patients. The technical success was 100%. Stent dilation was performed after deployment in 18 cases (78%). Stent migration into the right atrium occurred immediately after deployment in one patient; however, this stent was successfully repositioned and stabilized by a second stent. The clinical symptoms improved at least one category according to the International Consensus Committee on Chronic Venous Disease after stent implantation in all but one patient. The mean clinical follow-up was 66 days ± 83 (range, 1-305 d). Three minor complications (13%) and one major complication (4%) occurred. CONCLUSIONS Implantation of the self-expanding Sinus-XL stent for treatment of SVC obstruction caused by NSCLC is a safe and effective urgent treatment in this palliative setting.

Nine-year Experience: Prophylactic Cranial Irradiation in Extensive Disease Small-cell Lung Cancer

Background In 2007, the European Organization for Research and Treatment of Cancer (EORTC) study (ClinicalTrials.gov identifier, NCT00016211) demonstrated a beneficial effect on overall survival (OS) with the use of prophylactic cranial irradiation (PCI) for extensive disease (ED) small‐cell lung cancer (SCLC). Nevertheless, debate is ongoing regarding the role of PCI, because the patients in that trial did not undergo magnetic resonance imaging (MRI) of the brain before treatment. Also, a recent Japanese randomized trial showed a detrimental effect of PCI on OS in patients with negative pretreatment brain MRI findings. Materials and Methods We examined the medical records of 136 patients with ED SCLC who had initially responded to chemotherapy and undergone PCI from 2007 to 2015. The outcomes, radiation toxicity, neurologic progression‐free survival, and OS after PCI were analyzed. Survival and correlations were calculated using log‐rank and univariate Cox proportional hazard ratio analyses. Results The median OS and the median neurologic progression‐free survival after PCI was 12 and 19 months, respectively. No significant survival difference was seen for patients who had undergone MRI before PCI compared with patients who had undergone contrast‐enhanced computed tomography (P = .20). Univariate analysis for OS did not show a statistically significant effect for known cofactors. Conclusion In the present cohort, PCI was associated with improved survival compared with the PCI arm of the EORTC trial, with a nearly doubled median OS period. Also, the median OS was prolonged by 2 months compared with the irradiation arm of the Japanese trial. Micro‐Abstract In 2007, a European Organization for Research and Treatment of Cancer (EORTC) study demonstrated a beneficial effect on overall survival (OS) with the use of prophylactic cranial irradiation (PCI) in extensive disease small‐cell lung cancer. Nevertheless, debate is ongoing regarding the role of PCI, because the patients in that trial did not undergo imaging of the brain before treatment. Also, a recent Japanese randomized trial showed a detrimental effect of PCI on OS in patients with negative pretreatment brain magnetic resonance imaging findings. Of our patients, 87% underwent brain imaging before PCI. In the present retrospective analysis, we found that PCI leads to a nearly doubled median OS compared with the irradiation arm of the EORTC trial, with a 2‐month prolonged median OS compared with the irradiation arm of the Japanese trial.

Invasive lung cancer staging: influence of CT-guided core needle biopsy on onset of pleural carcinomatosis

In lung cancer patients with single peripheral lesions, CT-guided needle biopsies (CTNBs) are common for histological sampling. Recently published studies showed conflicting results for the influence of CTNB on the onset of pleural carcinomatosis (PC). In order to estimate the influence of CTNB on pleural tumor spread, 146 histologically confirmed cases of lung cancer diagnosed by CTNB were retrospectively compared to 112 control lung cancer patients diagnosed by non-CTNB. CTNB was not associated with an earlier onset of PC, identifying CTNB as a safe procedure for minimally invasive lung cancer staging.

Outcome in patients with small cell lung cancer re-irradiated for brain metastases after prior prophylactic cranial irradiation

OBJECTIVES Patients with brain metastases from small-cell lung cancer (SCLC) who underwent prior prophylactic cranial irradiation (PCI) are often treated with a second course of whole brain radiation therapy (Re-WBRT) or stereotactic radiosurgery (SRS) for purposes of palliation in symptomatic patients, hope for increased life expectancy or even as an alternative to untolerated steroids. Up to date there is only limited data available regarding the effect of this treatment. This study examines outcomes in patients in a single institution who underwent cerebral re-irradiation after prior PCI. METHODS We examined the medical records of 76 patients with brain metastases who had initially received PCI between 2008 and 2015 and were subsequently irradiated with a second course of cerebral radiotherapy. Patients underwent re-irradiation using either Re-WBRT (88%) or SRS (17%). The outcomes, including symptom palliation, radiation toxicity, and overall survival (OS) following re-irradiation were analyzed. Survival and correlations were calculated using log-rank, univariate, and multivariate Cox proportional hazards-ratio analyses. Treatment-related toxicity was classified according to CTCAE v4.0. RESULTS Median OS of all patients was 3 months (range 0-12 months). Median OS after Re-WBRT was 3 months (range 0-12 months). Median OS after SRS was 5 months (range 0-12 months). Karnofsky performance status scale (KPS ≥50%) was significantly associated with improved OS in both univariate (HR 2772; p=0,009) and multivariate analyses (HR 2613; p=0,024) for patients receiving Re-WBRT. No unexpected toxicity was observed and the observed toxicity remained consistently low. Symptom palliation was achieved in 40% of symptomatic patients. CONCLUSIONS In conclusion, cerebral re-irradiation after prior PCI is beneficial for symptom palliation and is associated with minimal side effects in patients with SCLC. Our survival data suggests that it is primarily useful in patients with adequate performance status.

Generation of a New Disease-specific Prognostic Score for Patients With Brain Metastases From Small-cell Lung Cancer Treated With Whole Brain Radiotherapy (BMS-Score) and Validation of Two Other Indices

&NA; The purpose of this study was to develop a prognostic score for patients with brain metastases from SCLC treated with WBRT (BMS‐score). The new BMS score was more prognostic than the RPA and ds‐GPA score. BMS score and RPA showed the most significant differences between classes. Introduction: Patients with small‐cell lung cancer (SCLC) demonstrate an exception in the treatment of brain metastases (BM), because in patients with SCLC whole brain radiotherapy (WBRT) only is the preferred treatment modality. The purpose of this study was to develop a prognostic score for patients with brain metastases from SCLC treated with WBRT. Patients and Methods: The present study was conducted utilizing a single‐institution, previously described, retrospective database of patients with SCLC who were treated with WBRT (n = 221). Univariate and multivariate analyses were performed to generate the “brain metastases from SCLC score” (BMS score) based on favorable prognostic factors: Karnofsky performance status (KPS > 70), extracerebral disease status (stable disease/controlled), and time of appearance of BM (synchronous). Furthermore, the disease‐specific graded prognostic assessment score as well as the recursive partitioning analysis (RPA) were performed and compared with the new BMS score by using the log‐rank (Mantel‐Cox) test. Results: BMS score and RPA showed the most significant differences between classes (P < .001). BMS score revealed a mean overall survival (OS) of 2.62 months in group I (0‐1 points), 6.61 months in group II (2‐3 points), and 12.31 months in group III (4 points). The BMS score also identified the group with the shortest survival (2.62 months in group I), and the numbers of patients in each group were most equally distributed with the BMS score. Conclusion: The new BMS score was more prognostic than the RPA and disease‐specific graded prognostic assessment scores. The BMS score is easy to use and reflects known prognostic factors in contemporary patients with SCLC treated with WBRT. Future studies are necessary to validate these findings.

Large cell neuroendocrine lung carcinoma induces peripheral T-cell repertoire alterations with predictive and prognostic significance

OBJECTIVES This study was performed to evaluate for a potentially important role of T cells in the pathophysiology and treatment sensitivity of large cell neuroendocrine lung carcinoma (LCNEC), an orphan disease with poor prognosis and scarce data to guide novel therapeutic strategies. MATERIALS AND METHODS We performed T-cell receptor (TCR) β-chain spectratyping on blood samples of patients treated within the CRAD001KDE37 trial (n = 35) using age-matched current or former (n = 11) and never smokers (n = 10) as controls. The data were analyzed in conjunction with the complete blood counts of the probands as well as the data about response to treatment and overall survival in the clinical trial. RESULTS AND CONCLUSION Untreated stage IV LCNEC patients had significant T-cell repertoire alterations (p < 0.001) compared to age-matched smokers. These changes correlated positively with blood lymphocyte counts (r = 0.49, p < 0.01), suggesting antigen-induced T-cell proliferation as the causative mechanism. At the same time, LCNEC patients showed mild lymphopenia (1.54 vs. 2.51/nl in median, p < 0.01), which reveals a second, antigen-independent mechanism of systemic immune dysregulation. More pronounced T-cell repertoire alterations and higher blood lymphocyte counts at diagnosis were associated with a better treatment response by RECIST and with a longer overall survival (441 vs. 157 days in median, p = 0.019). A higher degree of T-cell repertoire normalization after 3 months of therapy also distinguished a patient group with more favourable prognosis (median overall survival 617 vs. 316 days, p = 0.036) independent of radiological response. Thus, LCNEC induces clinically relevant changes of the T-cell repertoire, which are measurable in the blood and could be exploited for prognostic, predictive and therapeutic purposes. Their pathogenesis appears to involve antigen-induced oligoclonal T-cell expansions superimposed on TCR-independent lymphopenia.

Synonymous EGFR variant p.Q787Q is neither prognostic nor predictive in patients with lung adenocarcinoma

Patients with non‐small cell lung cancer (NSCLC) harboring activating mutations in the Epidermal Growth Factor Receptor (EGFR) benefit from targeted therapies. A synonymous polymorphism (rs1050171, p.Q787Q) was shown to be associated with improved overall survival (OS) in colorectal cancer patients. As data in NSCLC are limited, we retrospectively analyzed associations of p.Q787Q with clinicopathological parameters including clinical response and outcome in patients with lung adenocarcinoma (ADC) who received tyrosine kinase inhibitor (TKI) therapy. Of 642 ADC patients whose tumors were profiled by next generation sequencing, 102 (15.9%) carried EGFR mutations targetable by TKIs (30.4% male patients, median age 65.1 y, 19.6% smokers with 12.8 median pack years). Seventy‐nine patients (77.5%) received TKI therapy either as a first‐ or second‐line therapy. Of the 102 EGFR‐mutant tumors, 72 (70.6%) exhibited the p.Q787Q polymorphism and another 12 (11.8%) cases with p.Q787Q harbored an additional TKI insensitive mutation (p.T790M). The polymorphism was neither associated with classic clinicopathological parameters nor with overall survival (21.1 months vs. 20.1 months; P‐value = 0.91) or clinical response (P‐value = 0.122). The patients with p.T790M had worse survival compared to EGFR activating mutation carriers with and without p.Q787Q when analyzed as a separate group (27.5 months, P‐value = 0.02). In conclusion, p.Q787Q is neither a suitable prognostic nor predictive biomarker for ADC patients receiving anti‐EGFR therapy in first‐ or second‐line of therapy.