Hepatocellular Carcinoma Cells and Their Fibrotic Microenvironment Modulate Bone Marrow-Derived Mesenchymal Stromal Cell Migration in Vitro and in Vivo

Abstract

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third cause of cancer-related death. Fibrogenesis is an active process characterized by the production of several proinflammatory cytokines, chemokines and growth factors. It involves the activation of hepatic stellate cells (HSCs) which accumulate at the site of injury and are the main source of the extracellular matrix deposits. There are no curative treatments for advanced HCC, thus, new therapies are urgently needed. Mesenchymal stromal cells (MSCs) have the ability to migrate to sites of injury or to remodeling tissues after in vivo administration; however, in several cancer models they demonstrated limited efficacy to eradicate experimental tumors partially due to poor engraftment. Thus, the aim of this work was to analyze the capacity of human MSCs (hMSCs) to migrate and anchor to HCC tumors. We observed that HCC and HSCs, but not nontumoral stroma, produce factors that induce hMSC migration in vitro. Conditioned media (CM) generated from established HCC cell lines were found to induce higher levels of hMSC migration than CM derived from fresh patient tumor samples. In addition, after exposure to CM from HCC cells or HSCs, hMSCs demonstrated adhesion and invasion capability to endothelial cells, type IV collagen and fibrinogen. Consistently, these cells were found to increase metalloproteinase-2 activity. In vivo studies with subcutaneous and orthotopic HCC models indicated that intravenously infused hMSCs migrated to lungs, spleen and liver. Seven days post-hMSC infusion cells were located also in the tumor in both models, but the signal intensity was significantly higher in orthotopic than in subcutaneous model. Interestingly, when orthotopic HCC tumors where established in noncirrhotic or cirrhotic livers, the amount of hMSCs localized in the liver was higher in comparison with healthy animals. A very low signal was found in lungs and spleens, indicating that liver tumors are able to recruit them at high efficiency. Taken together our results indicate that HCC and HSC cells produce factors that efficiently induce hMSC migration toward tumor microenvironment in vitro and in vivo and make MSCs candidates for cell-based therapeutic strategies to hepatocellular carcinoma associated with fibrosis.

Inflammatory Chemokines MIP-1δ and MIP-3α Are Involved in the Migration of Multipotent Mesenchymal Stromal Cells Induced by Hepatoma Cells

“…In line with others [60], we observed that conditioned medium from the human cell line Huh-7 was able to induce efficient migration in MSC similar to PDGF-BB, whereas conditioned medium from freshly isolated human hepatocytes and another hepatoma cell line, HepG2, did not. Therefore, the effect observed with the Huh-7 CM is specific to this type of cell line and is probably related to their unique secretory profile that we have analyzed.…”

Mesenchymal Stromal Cells Engineered to Produce IGF-I by Recombinant Adenovirus Ameliorate Liver Fibrosis in Mice

“…In vivo tracking of MSCs was performed as previously described [18]. In brief, MSCs were stained with CMDil for histological analysis and DiR (Molecular Probes, Invitrogen) for fluorescence imaging (FI).…”

A Specific Subpopulation of Mesenchymal Stromal Cell Carriers Overrides Melanoma Resistance to an Oncolytic Adenovirus

“…Once again MO-MSCs were shown to overexpress integrins that bind different collagens, including type I. Interestingly, both MD-MBA-231 breast cancer and A375N xenografts elicited an enhanced in vivo recruitment of MO-MSCs despite the fact that MDA-MB231 cells were not as efficient as melanoma cells to chemoattract MO-MSCs in vitro, suggesting that tumor-associated stromal cells might play a paracrine role in chemoattracting MO-MSCs in vivo. Further, the in vivo recruitment of MO-MSCs by experimental hepatocellular carcinoma was recently demonstrated by our group indicating that tumors with rather different types of stroma might all recruit MO-MSCs probably due to their enhanced capacity to adhere and migrate toward tumor stimulus [62]. Upon MO-MSCs systemic delivery, lungs and spleens showed minimal levels of engrafted MO-MSCs, with lung engraftment possibly related to initial microvascular trapping [63].…”