Inhibition of hyaluronic acid synthesis by 4-methylumbelliferone (4MU) reduces fibrosis in a murine model of orthotopic hepatocellular carcinoma (HCC) associated to liver fibrosis

PICCIONI FV; MALVICINI M; RIZZO MM; KIPPES N; ATORRASAGASTI C; RODRIGUEZ A; AMANTE M; FIORE E; BAYO J; AQUINO J; GARCÍA MG; ALANIZ L; MAZZOLINI G

Berlín

Congreso; 46th Annual Meeting - EASL; 2011

European Association for the Study of the Liver (EASL)

Liver fibrogenesis is characterized by an excessive production and deposition of extracellular matrix (ECM) components such as hyaluronic acid (HA), mainly produced by hepatic stellate cells (HSCs) that had transdifferentiated into myofibroblasts. These cells also increase alpha-smooth muscle actin (a-SMA) expression according to the degree of their activation state. The aim of this work was to analyze if HA synthesis inhibition by 4-methylumbelliferone (4MU) might reduce fibrosis development, and as a consequence, tumoral progression of HCC. For this aim, the Hepa129 HCC model was established in fibrotic livers, previously induced by repeated application of thioacetamide. 4MU effects on HSCs (LX2, CFSC-2G) were evaluated in vitro by analyzing proliferation and apoptosis, as well as on primary cultured hepatocytes. Fibrogenesis was also analyzed in vivo by performing Masson´s trichrome and Sirious Red stainings, labeling collagen fiber deposits, and by a-SMA immunohistochemistry. Morphometric analyses were applied for quantification. Results: 4MU treatment resulted in a 2-3 fold reduction in number of tumor satellites, and a reduction in proliferation (64% and 24%; for CFSC-2G and LX2 cells, respectively) and a induction in apoptosis of HSCs when compared to cultured hepatocytes, which remained unaffected. Animals treated with 4MU developed a reduced fibrosis degree when compared to control (F1-2 vs F2-3; Metavir). Consistently, the amount of collagen deposits were reduced in 4MU treated mice when compared to control, as seen by morphometric analyses and quantifying the a-SMA immunostained area.