Avaliação da atividade antifibrótica e antineoplásica hepáticas do composto CPBMF65, inibidor da enzima uridina fosforilase 1 humana : um estudo in vitro e in vivo

Abstract

Hepatic fibrosis, which was once considered to be merely the accumulation of scar tissue, is now recognized as being a dynamic process that can progress over time. However, although potentially reversible during the early stages, a significant number of patients progress to advanced fibrosis and terminal cirrhosis, increasing the risk of hepatocellular carcinoma (HCC). The search for new treatments with metabolic routes as defined molecular targets becomes evident and among the routes is the salvage pathway of pyrimidines, involved in the metabolism of nucleotides, precursors of DNA and RNA. The human uridine phosphorylase 1 (UPP1) enzyme plays an important role in this pathway, being responsible for the homeostatic concentration of uridine (Urd). The new synthetic molecule CPBMF65, inhibitor of UPP1 enzyme, has already demonstrated its biological effect by reducing the adverse effects caused by the chemotherapeutic 5-fluorouracil (5-FU). Urd levels are reduced in chronic liver diseases and UPP1 expression is increased in tumors when compared to normal tissues. In addition, Urd has been shown to inhibit inflammation and fibrosis in bleomycin-induced lung injury, decreasing collagen production. For these reasons, we believe that the compound CPBMF65 can demonstrate effects on the proliferation of hepatic stellate cells (GRX) and human hepatocarcinoma cells (HepG2), in addition to exerting a protective effect on hepatic fibrosis induced by carbon tetrachloride (CCl4) in mice C57BL/6. In this work, we demonstrated that the compound CPBMF65 caused the decrease of the cellular proliferation in the GRX and HepG2 lines without inducing cytotoxicity. GRX cells presented cell cycle arrest, significant increase in the percentage of senescent cells, increase of lipids droplets and decrease of cellular contraction. HepG2 cells also showed decreased proliferation and had similar increase of senescent cells. In addition, the subject compound has been shown to maintain the antiproliferative effect on HepG2 cells during prolonged treatment. C57BL/6 mice treated simultaneously with CCl4 and the molecule under study, had significant decrease of ALT, exhibiting anti-inflammatory and anti-fibrotic properties and decreased formation of collagen I and α-SMA. Considering its hepatoprotective effects, CPBMF65 can be considered a potential agent for treatment of both fibrosis and hepatocarcinoma.