To determine whether amifostine can induce elevated manganese superoxide dismutase (SOD2) in murine tissues and a transplantable SA-NH tumor, resulting in a delayed tumor cell radioprotective effect.
...SA-NH tumor-bearing C3H mice were treated with a single 400 mg/kg or three daily 50 mg/kg doses of amifostine administered intraperitoneally. At selected time intervals after the last injection, the heart, liver, lung, pancreas, small intestine, spleen, and SA-NH tumor were removed and analyzed for SOD2, catalase, and glutathione peroxidase (GPx) enzymatic activity. The effect of elevated SOD2 enzymatic activity on the radiation response of SA-NH cells was determined.
SOD2 activity was significantly elevated in selected tissues and a tumor 24 h after amifostine treatment. Catalase and GPx activities remained unchanged except for significant elevations in the spleen. GPx was also elevated in the pancreas. SA-NH tumor cells exhibited a twofold elevation in SOD2 activity and a 27% elevation in radiation resistance. Amifostine administered in three daily fractions of 50 mg/kg each also resulted in significant elevations of these antioxidant enzymes.
Amifostine can induce a delayed radioprotective effect that correlates with elevated levels of SOD2 activity in SA-NH tumor. If limited to normal tissues, this delayed radioprotective effect offers an additional potential for overall radiation protection. However, amifostine-induced elevation of SOD2 activity in tumors could have an unanticipated deleterious effect on tumor responses to fractionated radiation therapy, given that the radioprotector is administered daily just before each 2-Gy fractionated dose.
Retinoids are signaling molecules that are involved in proliferation, differentiation, and apoptosis during development. Retinoids exert their effects, in part, by binding to nuclear receptors, ...thereby altering gene expression. Clinical use of retinoids in the treatment of neuroblastoma is of interest due to their success in management of acute promyelocytic leukemia. Using the SK-N-SH human neuroblastoma cell line we investigated the effects of the differentiation agent all-trans-retinoic acid (ATRA) on the expression of manganese superoxide dismutase (MnSOD), an enzyme previously shown to enhance differentiation in vitro. Manganese superoxide dismutase mRNA, protein, and activity levels increased in a time-dependent manner upon treatment with ATRA. Nuclear levels of the NF-κB proteins p50 and p65 increased within 24 h of ATRA administration. This increase paralleled the degradation of the cytoplasmic inhibitor IκB-β. Furthermore an increase in DNA binding to a NF-κB element occurred within a 342-bp enhancer (I2E) of the SOD2 gene with 10 μM ATRA treatment. Reporter analysis showed that ATRA-mediated I2E-dependent luciferase expression was attenuated upon mutation of the NF-κB element, suggesting a contribution of this transcription factor to retinoid-mediated upregulation of MnSOD. This study identifies SOD2 as a retinoid-responsive gene and demonstrates activation of the NF-κB pathway in response to ATRA treatment of SK-N-SH cells. These results suggest that signaling events involving NF-κB and SOD2 may contribute to the effects of retinoids used in cancer therapy.
Abstract The AS04-adjuvanted human papillomavirus (HPV)16/18 vaccine, an L1-based vaccine, provides strong vaccine efficacy (VE) against vaccine-targeted type infections, and partial cross-protection ...to phylogenetically-related types, which may be affected by variant-level heterogeneity. We compared VE against incident HPV31, 33, 35, and 45 detections between lineages and SNPs in the L1 region among 2846 HPV-vaccinated and 5465 HPV-unvaccinated women through 11-years of follow-up in the Costa Rica HPV Vaccine Trial. VE was lower against HPV31-lineage-B (VE=60.7%;95%CI = 23.4%,82.8%) compared to HPV31-lineage-A (VE=94.3%;95%CI = 83.7%,100.0%) (VE-ratio = 0.64;95%CI = 0.25,0.90). Differential VE was observed at several lineage-associated HPV31-L1-SNPs, including a nonsynonymous substitution at position 6372 on the FG-loop, an important neutralization domain. For HPV35, the only SNP-level difference was at position 5939 on the DE-loop, with significant VE against nucleotide-G (VE=65.0%;95%CI = 28.0,87.8) but not for more the common nucleotide-A (VE=7.4%;95%CI = −34.1,36.7). Because of the known heterogeneity in precancer/cancer risk across cross-protected HPV genotype variants by race and region, our results of differential variant-level AS04-adjuvanted HPV16/18 vaccine efficacy has global health implications.
Abstract
Background
Testicular germ cell tumors (TGCTs) affect approximately 6 in 100,000 men with peak incidence in men 15 to 40 years of age. Established risk factors include family history of ...disease, undescended testis, contralateral TGCT, impaired fertility, and 21 GWAS susceptibility loci. Recent evidence suggests a 1.6 Mb deletion in the AZFc region (“gr/gr” deletion) of chromosome Y previously associated with male infertility is also associated with two- and three-fold increased risks of sporadic and familial TGCT, respectively. Furthermore, population-based studies have suggested mosaic chromosome Y loss in blood-derived DNA may be associated with increased risk of various solid tumors. Our aim was to investigate if mosaic loss across the entire Y chromosome is a TGCT risk factor.
Methods
We obtained blood and buccal-derived DNA from two studies: the NCI Familial Testicular Cancer Study (FTC, Cases = 172, Controls = 163) and NCI's US Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study (STEED, Cases = 506, Controls = 611). We designed a quantitative polymerase chain reaction (qPCR) with 15 probes spanning the Y chromosome to assess Y loss. Samples were run in triplicate across three batches and normalized to a standard curve. We quantified probe signals as a target to reference (T/R) ratio, and averaged ratios across the 15 probes to yield an overall Y chromosome signal.
Results
On average, men with TGCT had slightly lower mean T/R ratios compared with control men lacking TGCT (1.02 vs. 1.03). Multivariate logistic regression models adjusted for study batch effects detected no significant relationship between mean Y chromosome T/R ratio and TGCT risk (OR = 0.34, 95% CI = 0.10-1.17, P = 0.09). A similar null relationship was observed when using a threshold of 1.5 standard deviations below the mean T/R ratio to dichotomize between mosaic Y loss and no mosaic Y loss (OR = 0.59, 95% CI = 0.21-1.63, P = 0.31).
Conclusion
Our study suggests that mosaic chromosome Y loss, as measured by 15 probes spanning the Y chromosome, is not associated with either sporadic or familial TGCT risk. Further studies aimed at investigating the AZFc region of the Y chromosome are needed to better assess whether this locus is directly associated with TGCT risk or is indirectly associated by means of a shared relationship with impaired fertility.
Citation Format: Mitchell J. Machiela, Casey L. Dagnall, Anand Pathak, Jennifer T. Loud, Stephen J. Chanock, Mark H. Greene, Katherine A. McGlynn, Douglas R. Stewart. Mosaic chromosome Y loss is not associated with testicular germ cell tumor risk. abstract. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 811.
We examined the prevalence and nature of perceived problems in the interaction between physicians and patients diagnosed with hepatitis C virus (HCV) infection. This cross‐sectional study included ...322 outpatients diagnosed with chronic HCV infection and treated at a tertiary referral hospital's hepatology clinic. Patients were asked to provide demographic information and to complete a semistructured interview, the Sickness Impact Profile (SIP) and Hospital Anxiety Depression (HAD) scale. A team of two blinded coders analyzed the interviews. A total of 131 (41%) study patients reported communication difficulties with physicians involved in their care. The main difficulties were the poor communication skills of physicians (91 28%), physician incompetence regarding the diagnosis and treatment of HCV infection (74 23%), feelings of being misdiagnosed, misled, or abandoned (51 16%), or being stigmatized by their physician (29 9%). Patients were twice as likely to report difficulties with subspecialists as compared with generalists. Nonresponse with antiviral therapy correlated with perceived physician conflict even after adjusting for treatment in relation to the time of interview, whereas previous or ongoing substance abuse and mode of acquisition did not. In a multivariate model, patients' psychosocial problems were the best predictors of communication difficulties. In conclusion, a substantial number of patients with HCV infection report difficulties when interacting with physicians, which may be due to coexisting emotional or social problems. However, perceived stigmatization by physicians and a sense of abandonment reflect the need for further educational efforts. These should target both specialists and primary care providers to inform them about the psychosocial challenges facing these patients. (HEPATOLOGY 2004;39:999–1007.)
Increased reactive oxygen species (ROS) such as superoxide have been implicated as causal elements of oncogenesis. A variety of cancers have displayed changes in steady-state levels of key ...antioxidant enzymes, with the mitochondrial form of superoxide dismutase (MnSOD) being commonly implicated. Increasing MnSOD expression suppresses the malignant phenotype in various cancer cell lines and suppresses tumor formation in xenograft and transgenic mouse models. We examined the impact of MnSOD expression in the development of T cell lymphoma in mice expressing proapoptotic Bax. Lck-Bax38/1 transgenic mice were crossed to mice overexpressing MnSOD (Lck-MnSOD) as well as MnSOD+/− mice. The effects of MnSOD on apoptosis, cell cycle, chromosomal instability (CIN), and lymphoma development were determined. The apoptotic and cell cycle phenotypes observed in thymocytes from control and Bax transgenic mice were unaffected by variations in MnSOD levels. Remarkably, increased gene dosage of MnSOD significantly decreased aneuploidy in premalignant thymocytes as well as the onset of tumor formation in Lck-Bax38/1 mice. The observed effects of MnSOD support a role for ROS in CIN and tumor formation in this mouse model of T cell lymphoma.
Although β thalassemia is considered to be a classic monogenic disease, it is clear that there is considerable clinical variability between patients who inherit identical β globin gene mutations, ...suggesting that there may be a variety of genetic determinants influencing different clinical phenotypes. It has been suggested that variations in the structure or amounts of a highly expressed red cell protein (alpha hemoglobin stabilizing protein AHSP), which can stabilize free α globin chains in vitro, could influence disease severity in patients with β thalassemia. To address this hypothesis, we studied 120 patients with Hb E-β thalassemia with mild, moderate, or severe clinical phenotypes. Using gene mapping, direct genomic sequencing, and extended haplotype analysis, we found no mutation or specific association between haplotypes of AHSP and disease severity in these patients, suggesting that AHSP is not a disease modifier in Hb E-β thalassemia. It remains to be seen if any association between AHSP and clinical severity is present in other population groups with a high frequency of β thalassemia. (Blood. 2004;103:3296-3299)
This article integrates geological, biological, ethnographic, and archaeological lines of evidence to reconstruct fishing patterns between approximately 4100 and 500 BC in the northern Gulf of ...California. In addition to shell collecting along the coast, several species of fish were captured, mainly endemic sciaenids of the upper gulf. Our study focuses on the northern Sonoran coast where recent archaeological studies have discovered scores of otoliths (fish ear bones) in archaeological contexts. We report the species composition (chano, corvina, totoaba) and relative size of the prehistoric catch and discuss the modern biology of these species known to inhabit this area. Our evidence suggests that this area offered an important resource for Archaic hunters and gatherers who were drawn here to exploit fish at certain times of the year. Following sea level stabilization around 6,000 years ago, particular geomorphic settings provided opportunities to easily harvest large quantities of fish by spearing, netting, or hand catching them.
Nucleoside diphosphate kinases (NDKs) are implicated in a wide variety of cellular functions owing to their enzymatic conversion of NDP to NTP. NDK from Borrelia burgdorferi (BbNDK) was selected for ...functional and structural analysis to determine whether its activity is required for infection and to assess its potential for therapeutic inhibition. The Seattle Structural Genomics Center for Infectious Diseases (SSGCID) expressed recombinant BbNDK protein. The protein was crystallized and structures were solved of both the apoenzyme and a liganded form with ADP and vanadate ligands. This provided two structures and allowed the elucidation of changes between the apo and ligand‐bound enzymes. Infectivity studies with ndk transposon mutants demonstrated that NDK function was important for establishing a robust infection in mice, and provided a rationale for therapeutic targeting of BbNDK. The protein structure was compared with other NDK structures found in the Protein Data Bank and was found to have similar primary, secondary, tertiary and quaternary structures, with conserved residues acting as the catalytic pocket, primarily using His132 as the phosphohistidine‐transfer residue. Vanadate and ADP complexes model the transition state of this phosphoryl‐transfer reaction, demonstrating that the pocket closes when bound to ADP, while allowing the addition or removal of a γ‐phosphate. This analysis provides a framework for the design of potential therapeutics targeting BbNDK inhibition.
Structures of Borrelia burgdorferi nucleoside diphosphate kinase have been solved both in the native state and bound to ADP and vanadate to characterize its catalytic action. Visualization strategies and models demonstrate dynamic relationships of the enzyme and ligands, and help to define phosphate transfer by the enzyme. This reaction is important for infection within a mouse model and is a potential target for the development of therapeutics for Lyme disease.
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