In patients with liver cancer, CCL2 is highly expressed and is a prognostic factor. Blockade of CCL2/CCR2 signalling suppresses murine liver tumour growth via activating T cell antitumour immune response. The results demonstrate the translational potential of CCL2/CCR2 blockade for treatment of HCCs.
Hepatocellular carcinoma (HCC) is a common malignant tumor in the digestive tract with limited therapeutic choices. Although sorafenib, an orally administered multikinase inhibitor, has produced survival benefits for patients with advanced HCC, favorable clinical outcomes are limited due to individual differences and resistance. The application of immunotherapy, a promising approach for HCC is urgently needed. Macrophage infiltration, mediated by the CCL2/CCR2 axis, is a potential immunotherapeutic target. Here, we report that a natural product from Abies georgei, named 747 and related in structure to kaempferol, exhibits sensitivity and selectivity as a CCR2 antagonist. The specificity of 747 on CCR2 was demonstrated via calcium flux, the binding domain of CCR2 was identified in an extracellular loop by chimera binding assay, and in vivo antagonistic activity of 747 was confirmed through a thioglycollate-induced peritonitis model. In animals, 747 elevated the number of CD8 + T cells in tumors via blocking tumor-infiltrating macrophage-mediated immunosuppression and inhibited orthotopic and subcutaneous tumor growth in a CD8 + T cell-dependent manner. Further, 747 enhanced the therapeutic efficacy of low-dose sorafenib without obvious toxicity, through elevating the numbers of intra-tumoral CD8 + T cells and increasing death of tumor cells. Thus, we have discovered a natural CCR2 antagonist and have provided a new perspective on development of this antagonist for treatment of HCC. In mouse models of HCC, 747 enhanced the tumor immunosuppressive microenvironment and potentiated the therapeutic effect of sorafenib, indicating that the combination of an immunomodulator with a chemotherapeutic drug could be a new approach for treating HCC.
In this paper, we propose a vehicle-scheduling model for electric transit buses with either battery swapping or fast charging at a battery station, and a vehicle-scheduling model with the maximum route distance constraint for compressed natural gas, diesel, or hybrid-diesel buses. Both of these scheduling models are NP-hard. We develop column-generation-based algorithms to solve the scheduling problems. We conduct extensive case studies based on real-world instances and instances randomly generated in a practical setting. Our computational experiments show that our algorithms demonstrate very good computational performances. We also use real-world transit data to systematically analyze the number of buses needed, the total operational costs, and the vehicle emissions generated when compressed natural gas, diesel, hybrid, or electric buses are used in service.
BackgroundBenzo[a]pyrene (B[a]P) is a common environmental and foodborne pollutant. Although the carcinogenicity of high-dose B[a]P has been extensively reported, the effects of long-term B[a]P exposure at lower environmental doses on cancer development are less understood.ObjectivesWe investigated the impact of B[a]P on human hepatocellular carcinoma (HCC) progression at various levels of exposure and identified a potential intervention target.MethodsWe used a model based on human HCC cells exposed to various concentrations of B[a]P (i.e., 0.01, 1, or 100 nM) for 1 month to examine the effects of B[a]P on cell growth, migration, invasion, and angiogenicity. A bioluminescent murine model was established to assess tumor metastasis in vivo.ResultsChronic B[a]P exposure did not alter HCC cell growth but promoted cell migration and invasion both in vitro and in vivo. There was an negative association between B[a]P exposure and the survival of tumor-bearing mice. In addition, B[a]P-treated HCC cells recruited vascular endothelial cells and promoted tumor angiogenesis, possibly through elevating vascular endothelial growth factor secretion. Furthermore, the NF-κB pathway may be an adverse outcome pathway associated with the cumulative effects of B[a]P on HCC metastasis.ConclusionsThese findings a) indicate that B[a]P has effects on HCC progression; b) identify a possible adverse outcome pathway; and c) contribute to a better understanding of the adverse effects of chronic exposure of B[a]P to human health.CitationBa Q, Li J, Huang C, Qiu H, Li J, Chu R, Zhang W, Xie D, Wu Y, Wang H. 2015. Effects of benzo[a]pyrene exposure on human hepatocellular carcinoma cell angiogenesis, metastasis, and NF-κB signaling. Environ Health Perspect 123:246–254; http://dx.doi.org/10.1289/ehp.1408524
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