Environmental Toxicology最新文献

This study aims to elucidate the role of minichromosome maintenance protein 4 (MCM4) in malignant melanoma (MM) and explore the underlying mechanism. Initially, data from The Cancer Genome Atlas (TCGA) database and the Molecular Signature Database (MSigDB) were used to investigate the biological impact of MCM4 on MM. Further, a prognostic model using Cox regression analysis was developed to predict the overall survival (OS) rate in the MM patients. The effects of MCM4 on the proliferation, migration, and invasion abilities of MM (B16F0 and A375) cells were demonstrated using the CCK-8, colony formation, EDU, wound scratch, and Transwell assays. In subcutaneous tumor models in C57BL/6 mice in vivo, the expression levels of MCM4 in MM cells and tumors were detected using Western blot and immunofluorescence approaches. The bioinformatics analysis indicated that MCM4 was expressed higher in MM tissues than in the normal tissues (p < 0.05). The established OS prediction model could significantly contribute to devising follow-up strategies and treating MM patients. MCM4 knockdown resulted in reduced proliferation, migration, and invasion abilities of MM cells, which were reversed by MCM4 overexpression (p < 0.05). Moreover, MCM4 could activate the phosphatidylinositol 3'-kinase (PI3K)/AKT pathway in MM cells. The PI3K inhibitor (LY294002) could reverse the effects of MCM4 on MM cells. MCM4 could substantially prompt the tumor growth of MM in mice through the PI3K/AKT pathway in vivo. In summary, MCM4 prompted the development and metastasis of MM by activating the PI3K/AKT pathway.

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignant tumor, and it ranks 2nd in terms of mortality rate among all malignancies in Taiwan. Sorafenib is a multiple tyrosine kinase inhibitor that suppresses tumor cell proliferation and angiogenesis around tumors via different pathways. However, the survival outcome of advanced HCC patients treated with sorafenib is still unsatisfactory. Unfortunately, there are no clinically applicable biomarkers to predict sorafenib therapeutic efficiency in HCC thus far. We found that serpin peptidase inhibitor, clade G, member 1 (SERPING1) is highly associated with overall and recurrence-free survival rates in HCC patients and is also highly correlated with several clinical parameters. SERPING1 expression was increased with sorafenib in both the HCC cell extract and conditioned medium, which was also observed in sorafenib-resistant HepG2 and Huh7 cells. Sorafenib decreased cell viability and migration, which was similar to the effect of SERPING1 in HCC progression. Moreover, sorafenib inhibited both MMP-2 and MMP-9 activity and enhanced the expression of p-ERK in HCC cells. In summary, sorafenib reduces HCC cancer progression might through the p-ERK-MMP-2-MMP-9 cascade via upregulation of SERPING1. In the present study, the roles and molecular mechanisms of SERPING1 and its value as a marker for predicting sorafenib resistance and progression in HCC patients were examined. The results of the present study provide a deep understanding of the roles of SERPING1 in HCC sorafenib resistance, which can be applied to develop early diagnosis and prognosis evaluation methods and establish novel therapeutic targets for specifically treating HCC.

Human oral squamous cell carcinoma (OSCC) poses a significant health challenge in Asia, with current therapeutic strategies failing to improve the survival rates for OSCC patients sufficiently. To elucidate the effects of Nimbolide on OSCC cell proliferation and apoptosis, we performed a series of experiments, including cell proliferation assays, annexin V/PI assays, and cell cycle analysis. We further investigated nimbolide's role in modulating endoplasmic reticulum (ER) stress, reactive oxygen species (ROS) production, and mitochondrial dysfunction using flow cytometry. Additionally, Western blotting was used to detect apoptosis-related protein expression. Our findings reveal that nimbolide exerts its anti-proliferative effects on OSCC cells by inducing apoptosis. The nimbolide increased intracellular ROS levels and acceleration of cellular calcium accumulation, respectively promoting endoplasmic reticulum stress and cancer cell apoptosis. Furthermore, nimbolide activates the caspase cascade by altering the mitochondrial membrane potential and apoptotic protein expression, thereby inhibiting the viability of tumor cells. Our data show that Nimbolide suppresses tumor growth through the induction of ROS production, ER stress, and mitochondrial dysfunction, resulting in apoptosis in OSCC cells. Overall, our study highlights nimbolide as a potential natural compound for OSCC therapy.

Patients with chronic kidney disease (CKD) frequently develop uremic cardiomyopathy, characterized by mitochondrial dysfunction as one of its pathologically significant mediators. Given that PM_2.5 specifically targets cardiac mitochondria, exacerbating toxicity, this study addresses the potential alterations in the severity of PM_2.5 toxicity in the context of CKD conditions. Female Wistar rats were exposed to PM_2.5 at a concentration of 250 μg/m³ daily for 3 h for 21 days after which an adenine-induced CKD model was developed. While both PM_2.5 exposure and the induction of CKD in rats lead to cardiomyopathy, the CKD animals exposed to PM_2.5 exhibited a notably severe extent of myocardial hypertrophy and fibrosis. ECG recordings in CKD+ PM_2.5 animals revealed a depressed ST segment and prolonged QRS interval, with both PM_2.5 and CKD animals displaying an elevated ST segment. Subcellular level analysis confirmed a significantly low mitochondrial copy number and a severe decline in mitochondrial bioenergetic function in the CKD+ PM_2.5 group. The prominent decline in PGC1-α further affirmed the severe mitochondrial functional deterioration in CKD+ PM_2.5 animals compared to other experimental groups. Additionally, myocardial calcification was enhanced in CKD+ PM_2.5 animals, heightening the susceptibility of CKD animals to PM_2.5 toxicity. In summary, our findings suggest that the increased vulnerability of CKD myocardium to PM_2.5-induced toxicity may be attributed to severe mitochondrial damage and increased calcification in the myocardium.

Mevastatin (MVS) is known for its anti-inflammatory effects, potentially achieved by upregulating heme oxygenase-1 (HO-1), an enzyme involved in cytoprotection against oxidative injury. Nonetheless, the specific processes by which MVS stimulates HO-1 expression in human cardiac fibroblasts (HCFs) are not yet fully understood. In this study, we found that MVS treatment increased HO-1 mRNA and protein levels in HCFs. This induction was inhibited by pretreatment with specific inhibitors of p38 MAPK, JNK1/2, and FoxO1, and by siRNAs targeting NOX2, p47^phox, p38, JNK1, FoxO1, Keap1, and Nrf2. MVS also triggered ROS generation and activated JNK1/2 and p38 MAPK, both attenuated by NADPH oxidase or ROS inhibitors. Additionally, MVS promoted the phosphorylation of FoxO1 and Nrf2, which was suppressed by p38 MAPK or JNK1/2 inhibitor. Furthermore, MVS inhibited TNF-α-induced NF-κB activation and vascular cell adhesion molecule-1 (VCAM-1) expression via the HO-1/CO pathway in HCFs. In summary, the induction of HO-1 expression in HCFs by MVS is mediated through two primary signaling pathways: NADPH oxidase/ROS/p38 MAPK, and JNK1/2/FoxO1 and Nrf2. This research illuminates the underlying processes through which MVS exerts its anti-inflammatory effects by modulating HO-1 in cardiac fibroblasts.