Novel findings for the development of drug therapy for various liver diseases: Current state and future prospects for our liver regeneration therapy using autologous bone marrow cells for decompensated liver cirrhosis patients.

We have developed an in vivo mouse model [the green fluorescent protein (GFP) / carbon tetrachloride (CCl(4)) model] and reported that infused GFP-positive bone marrow cells administered via a tail vein efficiently repopulated cirrhotic liver tissue under conditions of persistent liver damage induced by CCl(4). Moreover, bone marrow cells infused into the liver improved liver function and ameliorated liver fibrosis with higher expression of matrix metalloproteinase 9 (MMP-9), consistent with improved survival rate. Based on these findings, we started a multicenter clinical trial of autologous bone marrow cell infusion (ABMi) therapy for decompensated liver cirrhosis patients and demonstrated the efficacy of this approach without unexpected complications. However, this therapy involves bone marrow aspiration under general anesthesia and is not indicated for patients for whom general anesthesia is difficult. We therefore aimed to develop a new liver regeneration therapy in which cells having a curative effect on liver cirrhosis are isolated and cultured from a small amount of autologous bone marrow aspirated under local anesthesia and infused back into the same subject. Herein, we present results for the GFP/CCl(4) model and ABMi therapy and future prospects for a new liver regeneration therapy.