Lebein, a snake venom disintegrin, suppresses human colon cancer cells proliferation and tumor-induced angiogenesis through cell cycle arrest, apoptosis induction and inhibition of VEGF expression

Abstract

Lebein, is an heterodimeric disintegrin isolated from Macrovipera lebetina snake venom that was previously characterized as an inhibitor of ADP-induced platelet aggregation. In this study, we investigated the effect of Lebein on the p53-dependent growth of human colon adenocarcinoma cell lines. We found that Lebein significantly inhibited LS174 (p53wt), HCT116 (p53wt), and HT29 (p53mut) colon cancer cell viability by inducing cell cycle arrest through the modulation of expression levels of the tumor suppression factor p53, cell cycle regulating proteins cyclin D1, CDK2, CDK4, retinoblastoma (Rb), CDK1, and cyclin-dependent kinase inhibitors p21 and p27. Interestingly, Lebein-induced apoptosis of colon cancer cells was dependent on their p53 status. Thus, in LS174 cells, cell death was associated with PARP cleavage and the activation of caspases 3 and 8 while in HCT116 cells, Lebein induced caspase-independent apoptosis through increased expression of apoptosis inducing factor (AIF). In LS174 cells, Lebein triggers the activation of the MAPK ERK1/2 pathway through induction of reactive oxygen species (ROS). It also decreased cell adhesion and migration to fibronectin through down regulation of α5β1 integrin. Moreover, Lebein significantly reduced the expression of two angiogenesis stimulators, Vascular Endothelial Growth Factor (VEGF) and Neuropilin 1 (NRP1). It inhibited the VEGF-induced neovascularization process in the quail embryonic CAM system and blocked the development of human colon adenocarcinoma in nude mice. Overall, our work indicates that Lebein may be useful to design a new therapy against colon cancer. © 2016 Wiley Periodicals, Inc.

Evodiamine Induces Apoptosis, G2/M Cell Cycle Arrest, and Inhibition of Cell Migration and Invasion in Human Osteosarcoma Cells via Raf/MEK/ERK Signalling Pathway

“…Apoptosis is an important and highly conserved type of cell death that is considered imperative for normal developmental processes, host defense, and inhibition of oncogenesis [17]. Deregulated apoptosis is a characteristic of cancer cells, and molecules that stimulate apoptosis in cancer cells may prove beneficial in the development anticancer chemotherapy [18]. Interestingly, in the present study, Evodiamine did induce apoptosis in U2OS osteosarcoma cells.…”

Asteraceae Artemisia campestris and Artemisia herba-alba Essential Oils Trigger Apoptosis and Cell Cycle Arrest in Leishmania infantum Promastigotes

“…The lactate dehydrogenase (LDH) is a stable cytoplasmic enzyme that is rapidly released into the cell-culture supernatant when the plasma membrane is damaged [37]. Parasites (10 6 /mL) were cultured in 24-well plates and stimulated with both essential oils at the highest concentrations tested (0.5  μ L/mL), while vehicle- (0.05% DMSO-) treated cells were used as controls.…”

“…Parasites (10 6 /mL) were treated with increasing concentrations of both essential oils for 24 and 72 h. At each time point, cells were fixed with 70% chilled ethanol and kept at −20°C until analysis. After washing twice with PBS, cells were treated with DNase-free ribonuclease (20  μ g/mL) and stained with 20  μ g propidium iodide (PI) for 15 min at room temperature in the dark [37]. Data acquisition was carried out using a FACS flow cytometer and analyzed using CellQuest software.…”

“…After 24 and 72 h incubation with essential oils, promastigotes (10 6 cells/mL) were washed in phosphate-buffered saline (PBS) and centrifuged at 1800 rpm (630 g) for 10 min. Then, they were stained with annexin V-PE/7-AAD for 15 min in the dark at room temperature [37]. Acquisition was performed using a BD Biosciences flow cytometer.…”

“…The cells were cultured at 37°C and 5% CO 2 (6 × 10 5 cells/mL) in 96-well plates (200  μ L/well) for MTT assay and in 24-well plates (1 mL/well) for coloration. Cells were allowed to adhere for 24 h. After washing with PBS to eliminate nonadherent cells, macrophages were stimulated with different concentrations of essential oils (0–240  μ g/mL) for 24 h. Cytotoxicity was evaluated by adding MTT (1 mg/mL each well) [37] to the 96-well plates. The supernatant was discarded and the formazan crystals were dissolved with 100  μ L DMSO/well.…”