Mesenchymal stromal cells priming with autocrine motility factor increase their recruitment towards hepatocellular carcinoma.

BAYO J; FIORE E; PICCIONI F; BOLONTRADE M; SGANGA L; MALVICINI M; PEIXOTO E; RIZZO M; ALANIZ L; AQUINO JB; ANDRIANI O; PODHAJCER O; GARCIA MG; MAZZOLINI G

Congreso; 12º Reunión Anual de ISSCR (International Society for Stem Cell Research).; 2014

Incidence and mortality of hepatocellular carcinoma (HCC) continues increasing, and curative therapies can only be applied to a minority of patients. Particularly, several proinflammatory cytokines, chemokines and growth factors produced by tumor stroma have the ability to reclute the mesenchymal stromal cells. However, the mechanisms involved in human MSCs (hMSCs) migration and anchorage to HCC are not fully elucidated. Moreover, MSC were used as carriers of antitumoral genes towards HCC exploiting their capability of homing into HCC, however enhance their recruitment into tumor is a need. In this context Autocrine Motility Factor (AMF) a cytokine released by HCC cells can stimulate tumor cells motility, MMPs secretion, and enhancement of integrin β-1 activity. The aim of this study was analyze the role of AMF in MSC migration towards HCC For that purpose, in vitro migration was studied by modified Boyden chambers, observing that MSC not only migrate to recombinant AMF (rAMF) but also the AMF blocking with an specific antibody reduce their migration toward conditioned medium (CM) derived from HCC tumors developed in mice (HuH7 y HC-PT-5). Similarly zymography assays shown that MMP-2 activity is induced by the stimulation of MSC with rAMF or HuH7-CM. Moreover the specific blocking of AMF in HuH7-CM reduces the MMP-2 activity increasement. Finally, MSC were primed with rAMF (MSC-rAMF) and compared their migration capability with unstimulated MSC. MSC-rAMF shown an increased in vitro migration towards CM derived from both HCC tumors, and an increased adhesion to endothelial cells. MSC-rAMF also have an induction in the mRNA levels of AMF receptor, MMP-3, CAV-1, CAV-2 and the inhibition of GDI-2. Western blot shown that MSC-rAMF have an increased protein level of AMFR, JNK, p-JNK, c-Fos, p-c-Fos and p-CREB. In order to evaluate MSC in vivo migration, HCC cell line HuH7 was subcutaneously inoculated in BALB/c nude mice and then CMDiI-DiR-labeled hMSCs were intravenously injected. Three days later mice were sacrificed, tumor, liver, spleen and lung dissected and analyzed by using the Xenogen In Vivo Imaging System. In-vivo migration shown those tumors from animals with MSC-rAMF have an increased signal in comparison with control mice. Liver, lung or spleen do not have difference in their signal levels comparing both groups. Moreover, the presence of CM-DiI (+) MSC in tumors were confirmed by fluorescent microscopy. Our results shown not only that AMF plays a critical role in MSC recruitment to HCC, but also that MSC priming with rAMF enhance their migration to hepatocellular carcinoma becoming a promising strategy for improve their therapeutic efficacy.