INVESTIGADORES
GARCIA Mariana Gabriela
congresos y reuniones científicas
Título:
Migration capacity of human mesenchymal stromal cells towards hepatocellular carcinoma.
Autor/es:
GARCÍA MG; BAYO J; BOLONTRADE M; MALVICINI M; ALANIZ L; AQUINO JB; RODRÍGUEZ A; LORENTI A; ANDRIANI O; PODHAJCER O; MAZZOLINI G
Lugar:
Ontario
Reunión:
Congreso; 9º Reunión Anual de ISSCR (International Society for Stem Cell Research); 2011
Resumen:
Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the third cause of cancer-related death worldwide. Unfortunately, the incidence and mortality associated with HCC is increasing steadily. In the majority of patients HCC is associated with advanced fibrosis or cirrhosis. Several proinflammatory cytokines, chemokines and growth factors are produced by tumor stroma and also by cirrhotic livers. It is known that mesenchymal stromal cells (MSCs) have the ability to migrate to sites of injury or to remodeling tissues after in vivo administration. The aim of this work was to study the mechanisms involved in human MSCs (hMSCs) migration and anchorage to HCC in order to use them for delivery of therapeutic genes. For that purpose, in vitro migration was studied by modified Boyden chambers, observing that MSC displayed a high migration towards conditioned medium (CM) derived from human HCC cell lines (Hep3B, HuH7, PLC/PRF/5, HC-PT-5), from human tumor samples and also from human hepatic stellate cells (LX-2 cell line), but not to components of the stroma such as fibroblast or endothelial cells. We also observed that CM obtained from monolayer tumor cells induced higher migration in hMSCs than CM obtained from ex vivo tumors and also from multicellular spheroids composed by tumor cells, endothelial cells and activated hepatic stellate cells. Adhesion of hMSCs was observed at 5 min after exposure to tumor CM to fibronectin and collagen and at 30 min to endothelial cells. To further characterize the effect of HCC CM on hMSCs, invasion assays were performed observing that CM from HCC cell lines and LX-2 induced hMSC invasion to fibronectin and collagen and also increased metalloproteinase activity (MMP-2). In order to evaluate hMSC in vivo migration, HCC cell line HuH7 was subcutaneously inoculated in BALB/c nude mice and then CMDiI-DiR-labeled hMSCs were intravenously injected. Biodistribution of hMSCs was monitored by bioluminescence imaging using the Xenogen In Vivo Imaging System. Within the first hour, hMSCs located into the lungs; after 24 hours cells were observed also in the liver and spleen and around 7 days hMSCs were identified within the tumors. However, CM derived from tumors but not from spleen, liver or lungs induced hMSC migration in vitro. Mice were sacrificed and the presence of hMSCs was confirmed by visualization of CMDiI positive cells in the isolated organs. Our results indicate that factors produced by HCC and activated stellate cells induced hMSC migration, adhesion to extracellular matrix components and invasion capacity. Our results also demonstrate that CM obtained from monolayers cultures induced higher levels of hMSC migration in comparison with CM obtained from fresh tumors, indicating the relevance of studying hMSC migration in “a real system”. A proper understanding of hMSC migratory mechanisms to the tumor sites could have important implications for effective cellular delivery of therapeutic agents in HCC therapies.