ABSTRACT
Angiogenesis is considered one of the hallmarks of cancer, assisting tumor progression and metastasis. The mesoionic compound, MI-D, can induce cell death and provoke cytoskeletal and metabolic changes in cancer cells. Using in vitro and in vivo models, this study aimed to evaluate the effects of MI-D on the viability of human endothelial cells (EC) and its ability to inhibit tumor-induced angiogenesis induced by tumoral cells. For in vitro analysis, colon carcinoma (HT29) and endothelial (EA.hy926) cells were used as the tumoral and angiogenesis models, respectively. To evaluate cytotoxicity, methylene blue viability stain and annexin-V/7AAD tests were performed with both cell types. For the angiogenesis experiments, scratch wound healing and capillary tube-like formation assays were performed with the EC. The in vivo tests were performed with the chorioallantoic membrane (HET-CAM) methodology, wherein gelatin sponge implants containing MI-D (5, 25, and 50 µM), HT29 cells, or both were grafted in the CAM. Our data showed that MI-D induced apoptosis in both endothelial and colon carcinoma cells, with a strong cytotoxic effect on the tumoral lineage. The drug inhibited the EC's migration and capillary-like structure formation in vitro. In the HET-CAM assays, MI-D reduced the number of blood vessels in the membrane when grafted alone and accompanied by tumor cells. In this study, MI-D interfered in important steps of angiogenesis, such as maintenance of endothelial cell viability, migration, formation of capillary-like structures, as well tumor-induced neovascularization, reinforcing the hypothesis that MI-D might act as an inhibitor of angiogenesis, and a potential antitumor agent.
