Identificação de novas orto-aminoanilidas planejadas como inibidores multialvo de HDACs de classe I e PAN-PI3K para o tratamento antitumoral

Abstract

The objectives of this study were the rational design, synthesis, and biochemical evaluation of new molecular hybrids designed as multi-target inhibitors of phosphatidylinositol-3-kinase (PI3K) and class I histone deacetylases (HDACs). The development of the new inhibitors originated from structural modifications to LASSBio-2208, a potent inhibitor of PI3Ks and HDAC6/8. Based on this prototype, eight novel compounds were designed through the molecular hybridization of LASSBio-2208 with mocetinostate. The synthesis began with cyanuric chloride, which underwent aromatic nucleophilic substitution reactions with cyclic or aromatic amines and, subsequently, a Suzuki-type carbon-carbon coupling reaction. The tri-substituted triazine intermediates underwent an amidation reaction with activating agents and subsequent treatment with functionalized amines, resulting in the final amides with overall yields ranging from 18% to 60%. The thermodynamic solubility of the compounds in water was determined, revealing them to be insoluble at concentrations ≥ 3 μM. Next, the permeation profile was studied using the parallel artificial membrane permeability assay (PAMPA), simulating the gastrointestinal tract (GIT) and blood-brain barrier (BBB). In this assay, most compounds were able to permeate the BBB, while exhibiting low permeation through the GIT. The compounds were then evaluated for their enzymatic inhibition profiles against PI3Kα and HDAC1 and/or 2, leading to the identification of LASSBio-2402, LASSBio-2403, and LASSBio -2404 as potent morpholino-triazine hybrids containing the ortho-aminoanilide moiety, exhibiting potency against PI3Kα of 17, 368, and 14 nM, respectively, and against HDAC1/2 of 170/5200, 235/656, and 69/137 nM, respectively. Molecular docking studies suggested the main expected pharmacophore interactions for the most promising compounds in the series. Once the potency and desired multi-target profile were confirmed, the compounds were tested in a cellular model, studying their cytotoxic response in a 72-hour MTT assay against human solid tumor cell lines (MCF7, PC3, and U-87) and hematological neoplasms (CCRF-CEM and MOLT-4). The compounds exhibited cytotoxic potency ranging from 0.20 to 7.23 μM across the different cell lines, proving to be more potent than the starting prototypes mocetinostate and LASSBio-2208.