Low-dose radiation-induced enhancement of thymic lymphomagenesis in Lck-Bax mice is dependent on LET and gender

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

Serum essential trace elements and toxic metals in Chinese diabetic retinopathy patients

Trace elements are essential for the proper functioning of proteins, enzymes, and transcriptional factors. However, toxic metals will compete with essential trace elements, and damage enzymatic activities and various physiological functions. We aimed to investigate the status of serum essential trace elements and toxic metals in Chinese diabetic retinopathy (DR) patients, and to analyze their associations.This retrospective study included 33 normal subjects (normal group), 44 type 2 diabetes mellitus (T2D) patients with DR (DR group), and 58 T2D patients without DR (diabetes mellitus [DM] group). Serum levels of zinc (Zn), manganese (Mn), cadmium (Cd), and cesium (Cs), were measured for all participants using inductively coupled plasma-mass spectrometry.The serum concentrations of Mn (0.0226 μg/L) and Zn (98.162 μg/L) were significantly lower in DR group, compared with both the DM group and normal group (P < 0.05). In contrast, the serum levels of Cs (0.0354 μg/L) and Cd (0.0149 μg/L) were significantly higher in DR group, compared with the normal group (Cs: z = 3.136, P = .002; Cd: z = 3.766, P < .0001). Similarly, the serum Cs level in the DM group was 0.0323 μg/L, which was significantly higher than that in the normal group (0.0167 μg/L, z = 2.692, P = .007). Moreover, the area under the receiver-operating characteristic curve values of Mn (0.753 [95% confidence interval, CI 0.635-0.872, P = .002]), and Cd (0.797 [95% CI 0.643-0.952, P = .003]) were significantly greater than those of Zn and Cs, for DR identification.Our results suggest that deficient essential trace elements and accumulated toxic metals were highly associated with the presence of DR.

The role of mitochondrial sirtuins in health and disease

Mitochondria play a critical role in energy production, cell signalling and cell survival. Defects in mitochondrial function contribute to the ageing process and ageing-related disorders such as metabolic disease, cancer, and neurodegeneration. The sirtuin family of deacylase enzymes have a variety of subcellular localisations and have been found to remove a growing list of post-translational acyl modifications from target proteins. SIRT3, SIRT4, and SIRT5 are found primarily located in the mitochondria, and are involved in many of the key processes of this organelle. SIRT3 has been the subject of intense research and is primarily a deacetylase thought to function as a mitochondrial fidelity protein, with roles in mitochondrial substrate metabolism, protection against oxidative stress, and cell survival pathways. Less is known about the functional targets of SIRT4, which has deacetylase, ADP-ribosylase, and a newly-described lipoamidase function, although key roles in lipid and glutamine metabolism have been reported. SIRT5 modulates a host of newly-discovered acyl modifications including succinylation, malonylation, and glutarylation in both mitochondrial and extra-mitochondrial compartments, however the functional significance of SIRT5 in the regulation of many of its proposed target proteins remains to be discovered. Because of their influence on a broad range of pathways, SIRT3, SIRT4, and SIRT5 are implicated in a range of disease-states including metabolic disease such as diabetes, neurodegenerative diseases, cancer, and ageing-related disorders such as hearing-loss and cardiac dysfunction. We review the current knowledge on the function of the three mitochondrial sirtuins, their role in disease, and the current outstanding questions in the field.

Understanding cancer development processes after HZE-particle exposure: roles of ROS, DNA damage repair and inflammation

During space travel astronauts are exposed to a variety of radiations, including galactic cosmic rays composed of high-energy protons and high-energy charged (HZE) nuclei, and solar particle events containing low- to medium-energy protons. Risks from these exposures include carcinogenesis, central nervous system damage and degenerative tissue effects. Currently, career radiation limits are based on estimates of fatal cancer risks calculated using a model that incorporates human epidemiological data from exposed populations, estimates of relative biological effectiveness and dose-response data from relevant mammalian experimental models. A major goal of space radiation risk assessment is to link mechanistic data from biological studies at NASA Space Radiation Laboratory and other particle accelerators with risk models. Early phenotypes of HZE exposure, such as the induction of reactive oxygen species, DNA damage signaling and inflammation, are sensitive to HZE damage complexity. This review summarizes our current understanding of critical areas within the DNA damage and oxidative stress arena and provides insight into their mechanistic interdependence and their usefulness in accurately modeling cancer and other risks in astronauts exposed to space radiation. Our ultimate goals are to examine potential links and crosstalk between early response modules activated by charged particle exposure, to identify critical areas that require further research and to use these data to reduced uncertainties in modeling cancer risk for astronauts. A clearer understanding of the links between early mechanistic aspects of high-LET response and later surrogate cancer end points could reveal key nodes that can be therapeutically targeted to mitigate the health effects from charged particle exposures.