The action of Amblyomma cajennense tick saliva in compounds of the hemostatic system and cytotoxicity in tumor cell lines

Abstract

Ticks are blood-feeding arthropods that secrete anticoagulant molecules to maintain the fluidity of the blood during its feeding. Tick saliva has many compounds with biological activities that interact directly with host systems, such as blood clotting, platelet aggregation, cell death, among others. Some reports show that there are proteins with anticancer properties in tick saliva. This paper reports some of the biological roles of the Amblyomma cajennense tick saliva, including Factor Xa and thrombin inhibition, action on platelet aggregation, and also preliminary cytotoxic effects on tumor cell lines. The crude saliva was tested in the coagulation, fibrinolysis and platelet aggregation systems. The protein profile of the crude saliva was examined through anion exchange chromatography performed in a FPLC system. The chromatography separated seven protein fractions (Pools I to VII), which biological activities were evaluated. Moreover, the cytotoxic effects of the crude saliva were evaluated on SK-MEL-28 (melanoma cells) and MIA PaCa-2 (pancreas adenocarcinoma cells) using the MTT assay, flow cytometry and fluorescence microscopy. The crude saliva was able to induce cell death on both cancer cells lines, and, interestingly, the cytotoxic effects were not observed on human fibroblasts, which were used as control. The present work opens perspectives for the characterization and development of new molecules involved in the hemostatic system and in cancer control.