ABSTRACT
Hepatocellular carcinoma (HCC) arises in the setting of advanced liver fibrosis, a dynamic and complex inflammatory disease. The tumor microenvironment (TME) is a mixture of cellular components including cancer cells, cancer stem cells (CSCs), tumor-associated macrophages (TAM), and dendritic cells (DCs), which might drive to tumor progression and resistance to therapies. In this work, we study the effects of 4-methylumbelliferone (4Mu) on TME and how this change could be exploited to promote a potent immune response against HCC. First, we observed that 4Mu therapy induced a switch of hepatic macrophages (MÏ) towards an M1 type profile, and HCC cells (Hepa129 cells) exposed to conditioned medium (CM) derived from MÏ treated with 4Mu showed reduced expression of several CSCs markers and aggressiveness. HCC cells incubated with CM derived from MÏ treated with 4Mu grew in immunosuppressed mice while presented delayed tumor progression in immunocompetent mice. HCC cells treated with 4Mu were more susceptible to phagocytosis by DCs, and when DCs were pulsed with HCC cells previously treated with 4Mu displayed a potent antitumoral effect in therapeutic vaccination protocols. In conclusion, 4Mu has the ability to modulate TME into a less hostile milieu and to potentiate immunotherapeutic strategies against HCC.
Subject(s)
Carcinoma, Hepatocellular/drug therapy , Hymecromone/pharmacology , Liver Neoplasms/drug therapy , Tumor Microenvironment/drug effects , Animals , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Dendritic Cells/drug effects , Disease Models, Animal , Drug Resistance, Neoplasm/drug effects , Gene Expression Regulation, Neoplastic , Humans , Hymecromone/adverse effects , Immunity/drug effects , Liver Cirrhosis/drug therapy , Liver Cirrhosis/genetics , Liver Cirrhosis/pathology , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Mice , Neoplastic Stem Cells/drug effects , Phagocytosis/drug effects , Signal Transduction/drug effects , Tumor-Associated Macrophages/drug effects , Xenograft Model Antitumor AssaysABSTRACT
The tumor microenvironment (TME) represents a complex interplay between different cellular components, including tumor cells and cancer stem cells (CSCs), with the associated stroma; such interaction promotes tumor immune escape and sustains tumor growth. Several experimental approaches for cancer therapy are focused on TME remodeling, resulting in increased antitumor effects. We previously demonstrated that the hyaluronan synthesis inhibitor 4-methylumbelliferone (4Mu) decreases liver fibrosis and induces antitumor activity in hepatocellular carcinoma (HCC). In this work, 4Mu, in combination with an adenovirus encoding interleukin-12 genes (AdIL-12), elicited a potent antitumor effect and significantly prolonged animal survival (p < 0.05) in an orthotopic HCC model established in fibrotic livers. In assessing the presence of CSCs, we found reduced mRNA levels of CD133+, CD90+, EpCAM+, CD44+, and CD13+ CSC markers within HCC tumors (p < 0.01). Additionally, 4Mu downregulated the expression of the CSC marker CD47+ on HCC cells, promoted phagocytosis by antigen-presenting cells, and, combined with Ad-IL12, elicited a potent cytotoxic-specific T cell response. Finally, animal survival was increased when CD133low HCC cells, generated upon 4Mu treatment, were injected in a metastatic HCC model. In conclusion, the combined strategy ameliorates HCC aggressiveness by targeting CSCs and as a result of the induction of anticancer immunity.
Subject(s)
CD47 Antigen/genetics , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/metabolism , Interleukin-12/metabolism , Liver Neoplasms/etiology , Liver Neoplasms/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Animals , Antigen-Presenting Cells/drug effects , Antigen-Presenting Cells/immunology , Antigen-Presenting Cells/metabolism , Biomarkers , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/therapy , Cell Line, Tumor , Cytotoxicity, Immunologic , Disease Models, Animal , Disease Progression , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hymecromone/pharmacology , Interleukin-12/genetics , Liver Neoplasms/pathology , Liver Neoplasms/therapy , Lymphocytes, Tumor-Infiltrating/drug effects , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/metabolism , Mice , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Phagocytosis/immunology , T-Lymphocytes/drug effects , Tumor Microenvironment/drug effects , Tumor Microenvironment/genetics , Tumor Microenvironment/immunology , Xenograft Model Antitumor AssaysABSTRACT
In colorectal carcinoma patients, distant metastatic disease is present at initial diagnosis in nearly 25% of them. The majority of patients with metastatic colorectal carcinoma have incurable disease; therefore, new therapies are needed. Agents derived from medicinal plants have already demonstrated therapeutic activities in human cancer cells. Antartina is an antitumor agent isolated from Deschampsia antarctica Desv. This study aimed to evaluate the antitumor properties of Antartina in colorectal carcinoma models. We used human and murine colorectal carcinoma cell lines for investigating proliferation, apoptosis, and cell-cycle effects of Antartina therapy in vitro Avatar and immunocompetent colorectal carcinoma animal models were applied for evaluating the effects of Antartina in vivo Immune response against colorectal carcinoma model was investigated using CTL assay, analyzing dendritic cell activation and intratumor T-cell subpopulation, and by tumor rechallenge experiments. Antartina inhibits in vitro human colorectal carcinoma cell proliferation; however, in vivo experiments in Avatar colorectal carcinoma model Antartina display a limited antitumor effect. In an immunocompetent colorectal carcinoma mice model, Antartina potently inhibited tumor growth and liver metastases, leading to complete tumor regressions in >30% of mice and increased animal survival. In addition, Antartina induced a potent specific cytotoxic T-cell response against colorectal carcinoma and a long-lasting antitumor immunity. Interestingly, Antartina increased tumor immunogenicity and stimulated dendritic cell activation. No toxic effects were observed at the doses employed. Our findings showed that Antartina has the ability to induce antitumor immunity against colorectal carcinoma and can be used to develop new tools for the treatment of colorectal carcinoma. Mol Cancer Ther; 17(5); 966-76. ©2018 AACR.
