The anti-angiogenic potential of (±) gossypol in comparison to suramin

The chick embryo chorioallantoic membrane model: a research approach for ex vivo and in vivo experiments

BACKGROUND

The chick chorioallantoic membrane (CAM) model has attracted a great deal of interest in pharmaceutical and biological research as an alternative or complementary in vivo assay to animal models. Traditionally, CAM assay has been widely used to perform some toxicological studies, specifically to evaluate the skin, ocular and embryo toxicity of new drugs and formulations, and perform angiogenesis studies. Due to the possibility to generate the tumors onto the CAM, this model has also become an excellent strategy to evaluate the metastatic potential of different tumours and test the efficacy of novel anticancer therapies in vivo. Moreover, in the recent years, its use has considerably grown in other research areas, including the evaluation of new anti-infective agents, the development of biodistribution studies and tissue engineering research.

OBJECTIVES

This manuscript provides a critical overview of the use of CAM model in pharmaceutical and biological research, especially to test the toxicity of new drugs and formulations and the biodistribution and the efficacy of novel anticancer and anti-infective therapies, analyzing its advantages and disadvantages compared to animal models.

CONCLUSION

The chick chorioallantoic membrane model shows great utility in several research areas, such as cancer, toxicology, biodistribution studies and anti-infective therapies. In fact, it has become an intermediate stage between in vitro experiments and animal studies, and, in the case of toxicological studies (skin and ocular toxicity), has even replaced the animal models.

Antiangiogenic properties of lichen secondary metabolites

Lichens are symbiotic organisms which are composed fungi and algae and/or cyanobacteria. They produce a variety of characteristic secondary metabolites. Such substances have various biological properties including antimicrobial, antiviral, and antitumor activities. Angiogenesis, the growth of new vessels from pre-existing vessels, contributes to numerous diseases including cancer, arthritis, atherosclerosis, infectious, and immune disorders. Antiangiogenic therapy is a promising approach for the treatment of such diseases by inhibiting the new vessel formation. Technological advances have led to the development of various antiangiogenic agents and have made possible antiangiogenic therapy in many diseases associated with angiogenesis. Some lichens and their metabolites are used in the drug industry, but many have not yet been tested for their antiangiogenic effects. The cytotoxic and angiogenic capacities of lichen-derived small molecules have been demonstrated in vivo and in vitro experiments. Therefore, some of them may be used as antiangiogenic agents in the future. The secondary compounds of lichen whose antiangiogenic effect has been studied in the literature are usnic acid, barbatolic acid, vulpinic acid, olivetoric acid, emodin, secalonic acid D, and parietin. In this article, we review the antiangiogenic effects and cellular targets of these lichen-derived metabolites.

Endothelial Cell Glucose Metabolism and Angiogenesis

Angiogenesis, a process of new blood vessel formation from the pre-existing vascular bed, is a critical event in various physiological and pathological settings. Over the last few years, the role of endothelial cell (EC) metabolism in angiogenesis has received considerable attention. Accumulating studies suggest that ECs rely on aerobic glycolysis, rather than the oxidative phosphorylation pathway, to produce ATP during angiogenesis. To date, numerous critical regulators of glucose metabolism, fatty acid oxidation, and glutamine metabolism have been identified to modulate the EC angiogenic switch and pathological angiogenesis. The unique glycolytic feature of ECs is critical for cell proliferation, migration, and responses to environmental changes. In this review, we provide an overview of recent EC glucose metabolism studies, particularly glycolysis, in quiescent and angiogenic ECs. We also summarize and discuss potential therapeutic strategies that take advantage of EC metabolism. The elucidation of metabolic regulation and the precise underlying mechanisms could facilitate drug development targeting EC metabolism to treat angiogenesis-related diseases.

Nanoparticles Incorporating a Fluorescence Turn-on Reporter for Real-Time Drug Release Monitoring, a Chemoenhancer and a Stealth Agent: Poseidon's Trident against Cancer?

The rate and extent of drug release under physiological conditions is a key factor influencing the therapeutic activity of a formulation. Real-time detection of drug release by conventional pharmacokinetics approaches is confounded by low sensitivity, particularly in the case of tissue-targeted novel drug delivery systems, where low concentrations of the drug reach systemic circulation. We present a novel fluorescence turn-on platform for real-time monitoring of drug release from nanoparticles based on reversible fluorescence quenching in fluorescein esters. Fluorescein-conjugated carbon nanotubes (CNTs) were esterified with methotrexate in solution and solid phase, followed by supramolecular functionalization with a chemoenhancer (suramin) or/and a stealth agent (dextran sulfate). Suramin was found to increase the cytotoxicity of methotrexate in A549 cells. On the other hand, dextran sulfate exhibited no effect on cytotoxicity or cellular uptake of CNTs by A549 cells, while a decrease in cellular uptake of CNTs and cytotoxicity of methotrexate was observed in macrophages (RAW 264.7 cells). Similar results were also obtained when CNTs were replaced with graphene. Docking studies revealed that the conjugates are not internalized by folate receptors/transporters. Further, docking and molecular dynamics studies revealed the conjugates do not exhibit affinity toward the methotrexate target, dihydrofolate reductase. Molecular dynamics studies also revealed that distinct features of dextran-CNT and suramin-CNT interactions, characterized by π-π interactions between CNTs and dextran/suramin. Our study provides a simple, cost-effective, and scalable method for the synthesis of nanoparticles conferred with the ability to monitor drug release in real-time. This method could also be extended to other drugs and other types of nanoparticles.

Dihydroartemisinin Inhibits Proliferation and Induces Apoptosis of Human Hepatocellular Carcinoma Cell by Upregulating Tumor Necrosis Factor via JNK/NF-κB Pathways

Background

Dihydroartemisinin (DHA) is a predominant compound in Artemisia annua L., and it has been shown to inhibit tumorigenesis.

Methods

In this study, the antitumor potential of DHA was investigated in the MHCC97-L hepatocellular carcinoma cell line. Cells were treated at various concentrations of DHA, and then the cell cycle, viability, and DNA synthesis were measured to evaluate cell proliferation. Furthermore, the expression of genes and proteins related to proliferation and apoptosis was measured to determine the effects of DHA. Finally, the mechanism was investigated using RNA-sequencing to identify differentially expressed genes and signaling pathways, and JNK/NF-κB pathways were evaluated with Western blotting.

Results

Cells were treated with a concentration range of DHA from 1 to 100 μM, and cell proliferation was suppressed in a dose-dependent manner. In addition, the genes and proteins involved in typical cellular functions of MHCC97-L cells were significantly inhibited. DHA treatment downregulated the angiogenic gene ANGPTL2 and the cell proliferation genes CCND1, E2F1, PCNA, and BCL2. DHA treatment significantly upregulated the apoptotic genes CASP3, CASP8, CASP9, and TNF. Global gene expression profiles identified 2064 differentially expressed genes (DEGs). Among them, 744 were upregulated and 1320 were downregulated. Furthermore, MAPK, NF-kappa B, and TNF pathways were enriched based on the DEGs, and the consensus DEG was identified as TNF using a Venn diagram of those pathways. DHA promoted phosphorylation of JNK, inhibited nuclear p65, and then significantly induced TNF-α synthesis.

Conclusion

DHA inhibited cell proliferation and induced apoptosis in human hepatocellular carcinoma cells by upregulating TNF expression via JNK/NF-κB pathways.