In vivo and in vitro study of migratory capability of human mesenchymal stromal cells towards hepatocellular carcinoma and fibrosis

BAYO FINA, J; FIORE, E; PICCIONI, F; MARRODAN, M; BOLONTRADE, MF; PEIXOTO, E; LLOYD, R; RIZZO, M; ALANIZ, L; AQUINO, JB; PODHAJCER, O ; GARCIA, MG; MAZZOLINI, G

Boston

Simposio; 11th Annual Meeting. International Society for Stem Cell Research (ISSCR); 2013

International Society for Stem Cell Research (ISSCR)

Hepatocellular carcinoma (HCC) represents 85% to 90% of liver primary tumors and is the third-leading cause of cancer-related death in the world. Moreover, the incidence and mortality associated with HCC continues increasing worldwide. In most cases, HCC is developed in patients with liver cirrhosis; for this reason this condition is considered a preneoplasic stage. The hepatocarcinogenesis process involves an extensive exchange of signals between the tumor cells and their microenvironment, which is composed by several cell types, including hepatic stellate cells. Particulary, several proinflammatory cytokines, chemokines and growth factors, which are produced by tumor and stroma cells, are involved in this crosstalk. It is known that mesenchymal stromal cells (MSCs) have the ability to migrate in response to most of these soluble factors. The aim of this work was to study the in vitro and in vivo migration capability of MSCs towards HCC in order to use them for delivery of therapeutic genes. For that purpose, in vitro migration was studied by modified Boyden chamber, obserVing that MSC displayed a higher migration towards conditioned medium (CM) derived from fresh human samples of HCC compared with CM derived from non tumoral tissue. MSCs also showed a high ability to migrate towards CM derived from ex vivo tumors generated in nude mice by the inoculation of HuH? cell lines or a primary culture of HCC (HC-PT-5). We also found an increased migration to CM derived from liver or tumors derived from animals with liver fibrosis and intrahepatic tumors, when compared with the CM obtained from healthy mice. In order to evaluate hMSC in vivo migration, HCC cell line HuH7 was inoculated subcutaneously (s.c.) or intrahepatically (i.h.) in BALB/c nude mice. HuH7 tumors were also developed by intrahepatic inoculation in animals with subjacent fibrosis, induced by the administration of thioacetamide (i.h. TAA). Once tumors have developed, CMDil-DiR-labeled hMSCs were intravenously injected and biodistribution was monitored by fluorescence imaging (Xenogen In Vivo Imaging System). Seven days later, healthy and tumor bearing mice were sacrificed and MSCs were found in spleen, liver and lungs. Animals with tumors also presented MSCs signal in tumors. Moreover, liver and tumors from i.h. TM mice showed a stronger signal compared with the other groups. These results were confirmed by microscopy fluorescence visualization of CMDil+ cells in the isolated organs. Our results indicate that factors produced by HCC and fibrotic liver induce higher hMSC migration both in vivo and in vitro, compared with lungs and spleen, which showed a lower signal. Taking  together,our results indicates that soluble factors present in the tumor milieu induce the recruitment of MSC to HCC, making these cells a promising candidate for effective cellular delivery of therapeutic genes, not only against HCC but also fibrosis.