SAR131675 Receptor Tyrosine Kinase Inhibitor Induces Apoptosis through Bcl-2/Bax/Cyto c Mitochondrial Pathway in Human Umbilical Vein Endothelial Cells

Chondroitin sulfate-based universal nanoparticle delivers angiogenic inhibitor and paclitaxel to exhibit a combination of chemotherapy and anti-angiogenic therapy

Blocking the tumor nutrient supply through angiogenic inhibitors is an effective treatment approach for malignant tumors. However, using angiogenic inhibitors alone may not be enough to achieve a significant tumor response. Therefore, we recently designed a universal drug delivery system combining chemotherapy and anti-angiogenic therapy to target tumor cells while minimizing drug-related side effects. This system (termed as PCCE) is composed of biomaterial chondroitin sulfate (CS), the anti-angiogenic peptide ES2, and paclitaxel (PTX), which collectively enhance antitumor properties. Interestingly, the PCCE system is conferred exceptional cell membrane permeability due to inherent characteristics of CS, including CD44 receptor-mediated endocytosis. The PCCE could respond to the acidic and high glutathione conditions, thereby releasing PTX and ES2. PCCE could effectively inhibit the proliferation, migration, and invasion of tumor cells and cause apoptosis, while PCCE can affect the endothelial cells tube formation and exert anti-angiogenic function. Consistently, more potent in vivo antitumor efficacy and non-toxic sides were demonstrated in B16F10 xenograft mouse models. PCCE can achieve excellent antitumor activity via modulating angiogenic and apoptosis-related factors. In summary, we have successfully developed an intelligent and responsive CS-based nanocarrier known as PCCE for delivering various antitumor drugs, offering a promising strategy for treating malignant tumors.

SAR131675 exhibits anticancer activity on human ovarian cancer cells through inhibition of VEGFR-3/ERK1/2/AKT signaling pathway

Vascular endothelial growth factor receptor-3 (VEGFR-3) is known to participate in tumorigenesis and lymphangiogenesis, and as such, has the potential to serve as a molecular target for cancer therapy. SAR131675 is a highly selective VEGFR-3 antagonist that has an inhibitive effect on lymphatic cell growth. However, the anticancer effects and underlying mechanisms of SAR131675 in ovarian cancer remain poorly understood. In this study, we investigated the pathological role of VEGFR-3, and the effects of SAR131675 on proliferation, cell cycle, migration, and apoptosis in ovarian cancer cells. Our results showed that the mRNA and protein of VEGFR-3 were expressed in OVCAR3 and SKOV3 ovarian cancer cells, and this receptor was activated following stimulation with 50 ng/ml VEGF-C Cys156Ser (VEGF-CS), a selective ligand for VEGFR-3. Enhancing VEGFR-3 phosphorylation by treatment of ovarian cancer cells with VEGF-CS resulted in increased levels of phosphorylated extracellular signal-regulated kinases 1/2 (ERK1/2) and AKT. Moreover, our data demonstrated that SAR131675 inhibited VEGF-CS-mediated proliferation, colony formation, and migration of cancer cells in a dose-dependent manner. In addition, inhibition of VEGFR-3 activation with SAR131675 significantly increased cell cycle arrest and promoted apoptosis in both OVCAR3 and SKOV3 cells. Mechanistically, SAR131675 effectively suppressed the VEGF-CS-induced phosphorylation of VEGFR-3 and its downstream effectors including activated ERK1/2 and AKT in ovarian cancer cells. Our results reveal an anticancer activity of SAR131675 on the growth and migration of ovarian cancer cells, which may be through inhibiting VEGFR-3/ERK1/2/AKT pathway. SAR131675 may serve as an effective targeted drug for ovarian cancer.

Potential Role of Individual and Combined Effects of T-2 Toxin, HT-2 Toxin and Neosolaniol on the Apoptosis of Porcine Leydig Cells

T-2 toxin usually co-occurs with HT-2 toxin and neosolaniol (NEO) in the grains and feed. Our previous studies found that T-2 toxin and its metabolites’ binary or ternary combination exposure to porcine Leydig cells (LCs) displayed synergism in certain range of dosage and cannot be predicted based on individual toxicity. However, the possible mechanism of these mycotoxins’ combined exposure to cell lesions remains unknown. Based on 50% cell viability, the mechanism of apoptosis in porcine Leydig cells was investigated after exposure to T-2, HT-2, NEO individual and binary or ternary combinations. Compared with control, the adenosine triphosphate (ATP) content decreased, reactive oxygen species (ROS) level increased, and mitochondrial membrane potential (MMP) decreased in all treated groups. Additionally, the cell apoptosis rates were significantly increased in test groups (p < 0.05), and the B-cell lymphoma 2 (Bcl-2) Associated X (Bax)/Bcl-2 ratio and the expression of caspase 3, caspase 8, cytochrome c (Cytc) in the treated group are all significantly higher than the control group. Moreover, the expression of Cytc and caspase 8 gene in NEO and T-2+NEO groups was significantly higher than that in other individual and combined groups. It can be concluded that the toxicities of T-2, HT-2, and NEO individually and in combination can induce apoptosis related to the oxidative stress and mitochondrial damage, and the synergistic effect between toxins may be greater than a single toxin effect, which is beneficial for assessing the possible risk of the co-occurrences in foodstuffs to human and animal health.