Combined effects of GSTM1 and GSTT1 polymorphisms on breast cancer risk: A MOOSE-compliant meta-analysis and false-positive report probabilities test

Mitochondrial Glutathione in Cellular Redox Homeostasis and Disease Manifestation

Mitochondria are critical for providing energy to maintain cell viability. Oxidative phosphorylation involves the transfer of electrons from energy substrates to oxygen to produce adenosine triphosphate. Mitochondria also regulate cell proliferation, metastasis, and deterioration. The flow of electrons in the mitochondrial respiratory chain generates reactive oxygen species (ROS), which are harmful to cells at high levels. Oxidative stress caused by ROS accumulation has been associated with an increased risk of cancer, and cardiovascular and liver diseases. Glutathione (GSH) is an abundant cellular antioxidant that is primarily synthesized in the cytoplasm and delivered to the mitochondria. Mitochondrial glutathione (mGSH) metabolizes hydrogen peroxide within the mitochondria. A long-term imbalance in the ratio of mitochondrial ROS to mGSH can cause cell dysfunction, apoptosis, necroptosis, and ferroptosis, which may lead to disease. This study aimed to review the physiological functions, anabolism, variations in organ tissue accumulation, and delivery of GSH to the mitochondria and the relationships between mGSH levels, the GSH/GSH disulfide (GSSG) ratio, programmed cell death, and ferroptosis. We also discuss diseases caused by mGSH deficiency and related therapeutics.

Evaluation of molecular markers GSTM1 and GSTT1 and clinical factors in breast cancer: case-control study and literature review

The study was conducted to evaluate the frequency of polymorphisms in GSTM1 and GSTT1 genes in patients with breast cancer compared with individuals without history of cancer, and the association of these polymorphisms with clinical/epidemiological parameters.There were evaluated 752 women (219 patients and 533 controls). Molecular analysis was performed by the Polymerase Chain Reaction (PCR). Statistical analysis was used multiple logistic regression and descriptive statistics.Age ≥50 years (OR =3.22, 95% CI =2.30 - 4.51, p <0.001) and alcohol consumption (OR =1.60, 95% CI =1.13 - 2.27, p = 0.008) were associated to the development of breast cancer, while smoking and null genotypes GSTM1 and GSTT1 presented no association. GSTM1 and GSTT1 polymorphisms presented no relationship with the clinical and histopathological parameters or molecular subtypes of breast cancer. Ninety-two percent of tumors were invasive ductal, 66% were grade II, 65% were larger than 2 cm, the stages II (35.3%) and III (31.2%) were the most prevalent, and 47.7% were molecular subtype luminal B.Individuals aged ≥50 years and alcohol consumers have more chance to developing breast cancer. GSTM1 and GSTT1 polymorphisms are not associated to the risk of breast cancer.

A Pooling Genome-Wide Association Study Identifies Susceptibility Loci and Signaling Pathways of Immune Thrombocytopenia in Chinese Han Population

Immune thrombocytopenia (ITP) is an acquired bleeding disease due to immune-mediated destruction of antilogous platelets and ineffective thrombopoiesis. Although the etiology of ITP remains unknown, genetic variants are thought to predispose individuals to the disease. Several candidate gene analyses have identified several loci that increased ITP susceptibility, but no systematic genetic analysis on a genome-wide scope. To extend the genetic evidence and to identify novel candidates of ITP, we performed a pooling genome-wide association study (GWAS) by IlluminaHumanOmniZhongHua-8 combining pathway analysis in 200 ITP cases and 200 controls from Chinese Han population (CHP). The results revealed that 4 novel loci (rs117503120, rs5998634, rs4483616, and rs16866133) were strongly associated with ITP (P < 1.0 × 10⁻⁷). Expect for rs4483616, other three loci were validated by the TaqMan probe genotyping assay (P < 0.05) in another cohort including 250 ITP cases and 250 controls. And rs5998634 T allele was more sensitive to glucocorticoids for ITP patients (χ² = 7.30, P < 0.05). Moreover, we identified three overrepresented signaling pathways including the neuroactive ligand-receptor interaction, pathways in cancer, and the JAK-STAT pathway, which involved in the etiology of ITP. In conclusion, our results revealed four novel loci and three pathways related to ITP and provided new clues to explore the pathogenesis of ITP.