Potencial antineoplásico da crotoxina isolada do veneno da serpente Crotalus durissus terrificus: análise bioinformática e funcional no carcinoma epidermoide de boca

Abstract

Oral squamous cell carcinoma (OSCC) is a serious public health problem in several countries around the world and accounts for more than 90% of all malignant oral neoplasms. Treatments through chemotherapy and chemotherapy kill neoplastic cells and block biochemical mechanisms that promote tumor growth, promoting control of disease progression. Despite the advances obtained in the different treatment modalities, cases of therapeutic resistance and difficulty in treatment. In this sense, it is necessary to carry out the necessary research for the development of complementary therapies. The venoms obtained from animals of the Brazilian fauna are promising for the discovery of new antineoplastic agents. Crotoxin (CrTX) is a toxin isolated from the venom of the South American rattlesnake Crotalus durissus terrificus. It exerts immunomodulatory, anti-inflammatory, antimicrobial, antitumor and analgesic effects. With this in mind, two areas of work were investigated in this study. The first aimed to investigate, through bioinformatics analysis, the possible role of CrTX in oral cancer. For this, String, GeneCards and Cytoscape data were used for analysis of gene base analysis networks, leader gene and analysis between the genes involved in the mechanism of action of CrTX and oral carcinogenesis. The results showed a potential effect of the toxin on the apoptotic pathway on oral cancer, through the genes CYCS (Cytochrome C), CASP9, APAF1, tumor necrosis factor (TNF) and the apoptosis regulators, including BCL-2 and BIRC2 genes. The CYCS was identified as the leader gene related to the action of CrTX. After the development of the theoretical study of bioinformatics, the second aspect was developed, whose objective was to evaluate the antineoplastic potential of CrTX in oral squamous cell carcinoma, through phenotypic and functional assays in vitro and in vivo, in order to corroborate the results obtained. in the first study. Immortalized cells of CEB, SCC-4 and SCC-9, were treated with CrTX purified from Crotalus durissus terrificus snake venom, followed by cell viability and cell death assays, clonogenic formation, DNA fragmentation, migration assay and gene expression. with decreased expression of MMP2, MMP9, COL1A1, and increased CASP3. In the animal model, after induction of oral cancer by the carcinogen 4-nitroquinoline-1-oxide, mice were treated with CrTX to investigate its effects on tumor development in the tongue and oral mucosa. Crotoxin inhibited cell proliferation, viability, colony formation and migration, favoring cell death. In addition, it increased caspase-3 expression, decreased Ki-67 protein, mRNA expression of MMP2, MMP9 and COL1A1. The animals treated with CrTX at 10 µg/kg showed no alteration in the biochemical parameters of total cholesterol, very low density lipoprotein, high density lipoprotein, hepatic transaminases, glycemia, creatinine and urea. Treatment at this concentration significantly reduced the frequency of OSCC lesions by 50%. Thus, this study highlights CrTX as a promising chemotherapeutic substance, considering its effects in controlling the population of neoplastic cells, reducing cell migration and inhibiting tumor development. Clinical studies are needed to better understand the potential effects of this toxin as a potential adjuvant therapeutic agent for oral cancer patients.