Niels-Peter Becker

Bio: Niels-Peter Becker is an academic researcher from Charité. The author has contributed to research in topics: Selenoprotein & Selenoprotein P. The author has an hindex of 11, co-authored 20 publications receiving 456 citations. Previous affiliations of Niels-Peter Becker include Humboldt University of Berlin.

Selenium status is associated with colorectal cancer risk in the European prospective investigation of cancer and nutrition cohort

Abstract: Suboptimal intakes of the micronutrient selenium (Se) are found in many parts of Europe. Low Se status may contribute to colorectal cancer (CRC) development. We assessed Se status by measuring seru ...

Pre-diagnostic copper and zinc biomarkers and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort

Abstract: Adequate intake of copper and zinc, two essential micronutrients, are important for antioxidant functions Their imbalance may have implications for development of diseases like colorectal cancer (CRC), where oxidative stress is thought to be etiologically involved As evidence from prospective epidemiologic studies is lacking, we conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort to investigate the association between circulating levels of copper and zinc, and their calculated ratio, with risk of CRC development Copper and zinc levels were measured by reflection X-ray fluorescence spectrometer in 966 cases and 966 matched controls Multivariable adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression and are presented for the fifth versus first quintile Higher circulating concentration of copper was associated with a raised CRC risk (OR = 150; 95% CI: 106, 213; P-trend = 002) whereas an inverse association with cancer risk was observed for higher zinc levels (OR = 065; 95% CI: 043, 097; P-trend = 007) Consequently, the ratio of copper/zinc was positively associated with CRC (OR = 170; 95% CI: 120, 240; P-trend = 00005) In subgroup analyses by follow-up time, the associations remained statistically significant only in those diagnosed within 2 years of blood collection In conclusion, these data suggest that copper or copper levels in relation to zinc (copper to zinc ratio) become imbalanced in the process of CRC development Mechanistic studies into the underlying mechanisms of regulation and action are required to further examine a possible role for higher copper and copper/zinc ratio levels in CRC development and progression

Cooking of meat and fish in Europe: Results from the European Prospective Investigation into Cancer and Nutrition (EPIC)

Abstract: Objectives: There is epidemiologic evidence that the consumption of fried, grilled or barbecued meat and fish that are well-done or browned may be associated with an increased cancer risk. These high-temperature cooking methods are thought to be surrogates for mutagens and carcinogens produced in meat and fish, eg heterocyclic amines or polycyclic hydrocarbons. Since data on food cooking methods are scarce, the aim of this study was to describe the variation in meat and fish cooking methods in different parts of Europe. Design: Using a standardized 24 h recall from a sub-sample of the EPIC cohort (35 644 persons, 35-75 y old), mean daily intake of meat and fish prepared by different cooking methods and the relative contribution of the cooking methods to the overall cooking of meat and fish was calculated. Results: Whereas frying was more often noted in northern Europe, roasting and stir frying were more often used in the south. Concerning high-temperature cooking methods, their frequency of application varies between 15% in the EPIC cohort of North-Italy and 49% in the cohort of The Netherlands. Average consumption of fried, grilled and barbecued meat and fish ranges from a low of 12 g/day in the centres in southern Spain to a high of 91 g/day in northern Spain. Conclusion: High variation in both the kind of meat/fish consumed as well as its cooking methods is observed within EPIC. In order to use this variation for the evaluation of the impact of cooking methods on cancer risk, a questionnaire on meat and fish cooking methods is being developed and could be applied in the whole EPIC cohort.

An Improved Nonradioactive Screening Method Identifies Genistein and Xanthohumol as Potent Inhibitors of Iodothyronine Deiodinases

Abstract: Background: Deiodinases (DIO1, 2, and 3) are key enzymes in thyroid hormone (TH) activation and inactivation with impact on energy metabolism, development, cell differentiation, and a number of other physiological processes. The three DIO isoenzymes thus constitute sensitive rate-limiting components within the TH axis, prone to dysregulation by endocrine disruptive compounds or disease state. In animal models and cell culture experiments, they serve as readout for local TH status and disarrangement of the hormonal axis. Furthermore, some human diseases are characterized by apparent deiodinase dysregulation (e.g., the low triiodothyronine syndrome in critical illness). Consequently, these enzymes are targets of interest for the development of pharmacological compounds with modulatory activities. Until now, the portfolio of inhibitors for these enzymes is limited. In the clinics, the DIO1-specific inhibitor propylthiouracil is in use for treatment of severe hyperthyroidism. Other well-known inhibitors (e.g....

Hypoxia reduces and redirects selenoprotein biosynthesis.

Abstract: Selenium deficiency constitutes a risk factor for the incidence and negative course of severe diseases including sepsis, stroke, autoimmune diseases or cancer. In this study, hypoxia is identified as a powerful stimulus to redirect selenoprotein biosynthesis causing reduced selenoprotein P expression and diminished selenium export from hepatocytes in favour of increased biosynthesis of the essential protective intracellular phospholipid hydroperoxide glutathione peroxidase GPX4. Specifically, hypoxia decreases transcript concentrations of central factors controlling selenium and selenocysteine metabolism including selenophosphate synthetase-2, phosphoseryl-tRNA(SerSec) kinase and selenocysteine lyase, which are all proven to be rate-limiting enzymes in selenoprotein biosynthesis. These effects are paralleled by a general decline of selenoprotein expression; however, not all selenoproteins are affected to the same extent by hypoxia, and GPX4 constitutes an exception as its expression becomes slightly increased. Supplemental selenium is able to overcome the hypoxia-dependent down regulation of selenoprotein expression in our cell culture model system, supporting the concept of using selenium as an adjuvant treatment option in severe diseases. Although it remains to be tested whether these effects constitute a hepatocyte-specific response, the selenium-dependent decline of selenoprotein P biosynthesis under hypoxic conditions may explain the progressive selenium deficit developing in severe diseases.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Meat, Fish, and Colorectal Cancer Risk: The European Prospective Investigation into Cancer and Nutrition

Abstract: Background: Current evidence suggests that high red meat intake is associated with increased colorectal cancer risk. High fi sh intake may be associated with a decreased risk, but the existing evidence is less convincing. Methods: We prospectively followed 478 040 men and women from 10 European countries who were free of cancer at enrollment between 1992 and 1998. Information on diet and lifestyle was collected at baseline. After a mean follow-up of 4.8 years, 1329 incident colorectal cancers were documented. We examined the relationship between intakes of red and processed meat, poultry, and fi sh and colorectal cancer risk using a proportional hazards model adjusted for age, sex, energy (nonfat and fat sources), height, weight, workrelated physical activity, smoking status, dietary fi ber and folate, and alcohol consumption, stratifi ed by center. A calibration substudy based on 36 994 subjects was used to correct hazard ratios (HRs) and 95% confi dence intervals (CIs) for diet measurement errors. All statistical tests were two-sided. Results: Colorectal cancer risk was positively associated with intake of red and processed meat (highest [>160 g/day] versus lowest [ 80 g/day versus <10 g/day, HR = 0.69, 95 % CI = 0.54 to 0.88; P trend <.001), but was not related to poultry intake. Correcting for measurement error strengthened the associations between colorectal cancer and red and processed meat intake (per 100-g increase HR = 1.25, 95% CI =1.09 to 1.41, P trend = .001 and HR = 1.55, 95% CI = 1.19 to 2.02, P trend = .001 before and after calibration, respectively) and for fi sh (per 100 g increase HR = 0.70, 95% CI = 0.57 to 0.87, P trend <.001 and HR = 0.46, 95% CI = 0.27 to 0.77, P trend = .003; before and after correction, respectively). In this study population, the absolute risk of development of colorectal cancer within 10 years for a study subject aged 50 years was 1.71% for the highest category of red and processed meat intake and 1.28% for the lowest category of intake and was 1.86% for subjects in the lowest category of fi sh intake and 1.28% for subjects in the highest category of fi sh intake. Conclusions: Our data confi rm that colorectal cancer risk is positively associated with high consumption of red and processed meat and support an inverse association with fi sh intake. [J Natl Cancer Inst 2005;97:906–16]

Global survey of cell death mechanisms reveals metabolic regulation of ferroptosis

Abstract: Modulatory profiling of lethal small-molecule compounds identified FIN56 as an inducer of ferroptosis. FIN56 promotes the degradation of glutathione peroxidase 4 and directly activates squalene synthase, an enzyme involved in cholesterol synthesis.