Glycosylated 4-methylumbelliferone as a targeted therapy for hepatocellular carcinoma.

BACKGROUND & AIMS: Reaching efficacious drug delivery to target cells/tissues represents a major obstacle in the current treatment of solid malignancies including hepatocellular carcinoma (HCC). In this study, we developed a pipeline to selective add complex-sugars to the aglycone 4-methylumbelliferone (4MU) to help their bioavailability and tumour cell intake. METHODS: The therapeutic efficacy of sugar-modified rutinosyl-4-methylumbelliferone (4MUR) and 4MU were compared in vitro and in an orthotopic HCC model established in fibrotic livers. The mechanistic bases of its selective target to liver tumour cells were evaluated by the interaction with asialoglycoprotein receptor (ASGPR), the mRNA expression of hyaluronan synthases (HAS2 or HAS3) and hyaluronan deposition. RESULTS: 4MUR showed a significant antiproliferative effect on liver tumoural cells as compared to non-tumoural cells in a dose-dependent manner. Further analysis showed that 4MUR is incorporated mostly into HCC cells by interaction with ASGPR, a receptor commonly overexpressed in HCC cells. 4MUR-treatment decreased the levels of HAS2 and HAS3 and the cytoplasmic deposition of hyaluronan. Moreover, 4MUR reduced CFSC-2G activation, hence reducing the fibrosis. In vivo efficacy showed that 4MUR treatment displayed a greater tumour growth inhibition and increased survival in comparison to 4MU. 4MUR administration was associated with a significant reduction of liver fibrosis without any signs of tissue damage. Further, 60% of 4MUR treated mice did not present macroscopically tumour mass post-treatment. CONCLUSION: Our results provide evidence that 4MUR may be used as an effective HCC therapy, without damaging non-tumoural cells or other organs, most probably due to the specific targeting.

Antitumor effects of hyaluronic acid inhibitor 4-methylumbelliferone in an orthotopic hepatocellular carcinoma model in mice.

Liver cirrhosis is characterized by an excessive accumulation of extracellular matrix components, including hyaluronan (HA). In addition, cirrhosis is considered a pre-neoplastic disease for hepatocellular carcinoma (HCC). Altered HA biosynthesis is associated with cancer progression but its role in HCC is unknown. 4-Methylumbelliferone (4-MU), an orally available agent, is an HA synthesis inhibitor with anticancer properties. In this work, we used an orthotopic Hepa129 HCC model established in fibrotic livers induced by thioacetamide. We evaluated 4-MU effects on HCC cells and hepatic stellate cells (HSCs) in vitro by proliferation, apoptosis and cytotoxicity assays; tumor growth and fibrogenesis were also analyzed in vivo. Our results showed that treatment of HCC cells with 4-MU significantly reduced tumor cell proliferation and induced apoptosis, while primary cultured hepatocytes remained unaffected. 4-MU therapy reduced hepatic and systemic levels of HA. Tumors systemically treated with 4-MU showed the extensive areas of necrosis, inflammatory infiltrate and 2-3-fold reduced number of tumor satellites. No signs of toxicity were observed after 4-MU therapy. Animals treated with 4-MU developed a reduced fibrosis degree compared with controls (F1-2 vs F2-3, respectively). Importantly, 4-MU induced the apoptosis of HSCs in vitro and decreased the amount of activated HSCs in vivo. In conclusion, our results suggest a role for 4-MU as an anticancer agent for HCC associated with advanced fibrosis.