Atividade antitumoral e mecanismo de ação do derivado sintético 2-(3-hidroxi-1-metil-2-oxoindolin-3-il) acrilonitrila (CH3ISACN)

Abstract

With an estimated 704,000 new cases diagnosed in Brazil by 2025, cancer is currently one of the most prevalent diseases worldwide. Tumors that affect the Central Nervous System (CNS), such as gliomas, have a high mortality rate, among these, glioblastoma is the most common type in adults, with a patient survival rate of just 5% in up to 5 years. Despite the growing evolution of research involving the search for the treatment of these cases, the improvement in the clinical conditions of gliomas still remains unsatisfactory. In order to overcome this problem, the search for new substances with antineoplastic activity has grown, research carried out with isatin and its derivatives has shown a remarkable ability to inhibit the growth of cancer cells without affecting the normal development of healthy cells. Among these, the synthetic derivative of N-methylisatin (CH3ISACN), a synthetic derivative of isatin, is presented as a promising molecule, with antitumor activities in hepatocellular and lung cancer models already documented. The present study aimed to investigate the antitumor activity of the substance CH3ISACN, in experimental models of human glioblastoma, by carrying out cell viability assays using the U87 and U373-MG cell lines and investigating the mechanism of action of CH3ISACN using pharmacological blockers. In cytotoxicity assays, it was verified that CH3ISACN was cytotoxic to U373 and U87-MG cells, with IC50 of 24.26 and 24.23 µM, respectively. The selectivity index of the substance was calculated based on the IC50 of the human embryonic non-tumor cell (HEK-293), finding that CH3ISACN is 3 times more selective for tumor cells. In the assay using confocal microscopy, the morphologies of U87-MG tumor cells were verified at a concentration of 24 µM, indicating apoptosis as the type of death of tumor cells treated with the isatin derivative. CH3ISACN was able to reduce the formation of new colonies of U87MG cells, in addition to being able to disintegrate the spheroids (3D culture model), reducing the spheroid area to zero. An investigation of the cell death signaling pathway was carried out, through testing with pharmacological blockers and molecular docking, and the muscarinic and glutamatergic pathways do not participate in the substance's mechanism of action. In the molecular docking model, the MAPKs pathway was verified and the substance has a favorable interaction with the ERK protein.