Tetrabromobisphenol A (TBBPA), an emerging organic pollutant widely detected in human samples, has a positive correlation with the development of endometrial cancer (EC), but its underlying mechanisms have not yet been fully elucidated. Tumor-associated macrophages (TAM), one of the most vital components in tumor microenvironment (TME), play regulatory roles in the progression of EC. Consequently, this study mainly focuses on the macrophage polarization in TME to unveil the influence of TBBPA on the progression of EC and involved mechanisms. Primarily, low doses of TBBPA treatment up-regulated M2-like phenotype biomarkers in macrophage. The data from in vitro co-culture models suggested TBBPA-driven M2 macrophage polarization was responsible for the EC deterioration. Results from in vivo study further confirmed the malignant proliferation of EC promoted by TBBPA. Mechanistically, TBBPA-mediated miR-19a bound to the 3?-UTR regions of SOCS1, resulting in down-regulation of SOCS1 followed by the phosphorylation of JAK and STAT6. The present study not only revealed for the first time the molecular mechanism of TBBPA-induced EC?s deterioration based on macrophage polarization, but also established co-culture models, thus providing a further evaluation method for the exploration of environmental pollutants-induced tumor effects from the role of TME.
Tetrabromobisphenol A (TBBPA), one of the highly common industrial brominated flame retardants (BFRs), has been recently reported to influence the progression of endometrial carcinoma. However, the underlying mechanism between them has not been fully illuminated. Our findings demonstrated that treatment with low concentrations of TBBPA significantly induced the proliferation of Ishikawa cells in a concentration- and time-dependent manner. Mechanically, TBBPA stimulation led to the elevation of NF-κB expression, accompanied by the occurrence of ubiquitin-mediated IκB′ degradation. Additionally, the upregulation of pro-inflammatory cytokines upon TBBPA exposure was observed in both mRNA and protein levels. Interestingly, the above toxic effects of TBBPA on Ishikawa cells were markedly attenuated by the addition of MG-132, a proteasome inhibitor, suggesting the crucial role of ubiquitin-mediated IκB′ degradation in the TBBPA-stimulated proliferation of Ishikawa cells. Confirmation using in vivo model was also presented in this work. Accordingly, our data indicated that ubiquitin-mediated IκB′ degradation and inflammatory response could serve as critical and sensitive biomarkers for the TBBPA-induced endometrial carcinoma, which would be helpful for the future carcinogenic risk assessments of TBBPA exposure on uterus.
Due to the extensive applications and deleterious effects of Tetrabromobisphenol A (TBBPA), the health risk and possible mechanisms have been a topic of concern. However, the knowledge on carcinogenic risk of TBBPA and corresponding mechanisms remains scarce. In this study, endometrial cancer cells were exposed to low doses of TBBPA and its main derivatives including TBBPA bis (2,3-dibromopropyl ether) (TBBPA-BDBPE) and TBBPA bis (2-hydroxyethyl ether) (TBBPA-BHEE). The data from wound healing and transwell assays demonstrated that TBBPA treatment exhibited the strongest enhanced effect on cell migration among other tested treatments. Of note, the process of invasion rather than epithelial-mesenchymal transition (EMT) was accompanied by the occurrence of migration elevated by TBBPA. Furthermore, the levels of several metabolite indicators were measured to assess the underlying mechanisms involved in TBBPA-induced cell migration. The findings suggested that NADPH oxidase (NOX)-driven ROS instead of energy metabolism was sensitive to TBBPA stimulation. In addition, molecular docking supported a link between TBBPA ligand and NOX receptor. Accordingly, this study has provided new insights for TBBPA-induced carcinogenic effects and may arise peoples' vigilance to environmental pollution of brominated flame retardant.
Tetrabromobisphenol A (TBBPA) and its derivatives are the common flame-retardants that may increase the risk of development of many types of cancers, including liver cancer. However, the effects of TBBPA in the development and progression of liver cancer remains unknown. This study investigated the potential effects of TBBPA on a metastatic phenotype of hepatocellular carcinoma cell line-HepG2. Our results revealed that TBBPA significantly promoted the migration and invasion via affecting the number and distribution of lysosomes in HepG2 cells in a dose-dependent manner. Moreover, TBBPA decreased the intracellular protein levels of Beta-Hexosaminidase (HEXB), Cathepsin B (CTSB) and Cathepsin D (CTSD) while increased the extracellular CTSB and CTSD. It entailed that TBBPA exposure could promote the lysosomal exocytosis in cancer cells. The reversal results were obtained after adding lysosomal exocytosis inhibitor vacuolin-1. Docking results suggested that TBBPA could bind to TRPML1. It was consistent with the binding position of agonist ML-SA1. TRPML1 knockdown significantly decreased the invasion and migration, and the results were reversed when TBBPA was added. The results were indicated that TRPML1 was critical in lysosomal exocytosis. In addition, our results showed that TBBPA-TRPML1 complex regulated the calcium-mediated lysosomal exocytosis, thereby promoting the metastasis in liver cancer cells. It was expected that our data could provide important basis for understanding the molecular mechanism(s) of TBBPA promoting invasion and migration of hepatoma cells and give rise to profound concerns of TBBPA exposure on human health.
Fine particulate matter is one of the leading threats to cardiovascular health worldwide. The exploration of novel and sensitive biomarkers to detect damaging effect of fine particulate matter on cardiac tissues is of great importance in the better understanding of haze-caused myocardial injury. A link between heart failure and PPARα-regulated energy metabolism has been confirmed previously. Herein, the study intends to reveal the critical biomarkers of fine particulate matter induced myocardial damage from the PPARα-regulated energy metabolism. Ambient fine particulate matter induced severe pathological alterations in cultured cells, accompanied by the decrease in ATP content. Additionally, the expressions of CPT1/CPT2 and levels of CS and MDH, crucial members in β-oxidation and the TCA cycle, were significantly decreased. In direct contrast, fine particulate matter increased the biomarkers of glycolysis, as measured by the accumulation of pyruvate and lactate contents, and the enhanced activities of HK and PKM1/2. Importantly, fine particulate matter-exposed cardiomyocytes exhibited the reduced PPARα level, that increased when cardiomyocytes were co-incubation with WY-14643 and fine particulate matter. Simultaneously, the adverse impact of fine particulate matter on critical biomarkers were observed in β-oxidation, TCA cycle and glycolysis, associated with WY-14643 additional complement. Fine particulate matter caused the myocardial energy metabolism transformation through the regulation of PPARα expression and translation, which provided novel and critical biomarkers for haze particles-caused myocardial damage.
Airborne fine particles, generating from human activities, have drawn increasing attention due to their potential lung health hazards. The currently available toxicological data on fine particles is still not sufficient to explain their cause-and-effect. Based on well reported critical role of ATP on maintaining lung structure and function, the alterations of ATP production and energy metabolism in lungs of rats exposed to different dosages of seasonal PM2.5 were investigated. Haze dosage PM2.5 exposure was demonstrated to reduce the ATP production. Activity of critical enzymes in TCA cycle, such as malate dehydrogenase (MDH) and citrate synthase (CS), and expression of mitochondrial respiration chain genes were attenuated in groups exposed to haze dosage PM2.5. In contrast, there was prominent augment of glycolytic markers at haze dosage PM2.5, including metabolite contents (pyruvate and lactic acid), enzyme activities (hexokinase (HK) and pyruvate kinase (PKM)), along with mRNA levels of PKM and LDH. Consequently, sub-chronic exposure to seasonal haze PM2.5 caused reduction in ATP generation and metabolic rewiring from TCA cycle to glycolysis. Our findings can help better understand the toxicological mechanism of lung disease caused by particulate air pollution.