4Mu Decreases CD47 Expression on Hepatic Cancer Stem Cells and Primes a Potent Antitumor T Cell Response Induced by Interleukin-12.

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.

Targets and Strategies for Cancer Immunoprevention.

The immune system plays a key role in cancer prevention, initiation, and progression. Antitumoral immune responses can be boosted by harnessing antitumorigenic immune activators and/or blocking tumorigenic proinflammatory factors. Here we define these targets as well as the strategies that could be developed for effective cancer immunoprevention.

The influence of physical activity in the anti-tumor immune response in experimental breast tumor.

This study aimed to investigate the influence of physical activity in innate immunity to conduce to an effective antitumoral immune response analyzing the phenotype and activation status of infiltrating cells. We analysed the intracellular cytokines and the transcription factors of tumor infiltrating lymphocytes (TILS) and spleen leukocytes. The Nos2 gene expression was evaluated in spleen cells and futhermore the ROS production was measured and spleen cells; another cell evaluated was dendritic cells (TIDCs), their cytokines expression and membrane molecules; finally to understood the results obtained, we analysed the dendritic cells obtained from bone marrow. Were used female Balb/c mice divided into 4 groups: two controls without tumor, sedentary (GI) and trained (GII) and two groups with tumor, sedentary (GIII) or trained (GIV). The physical activity (PA) was realized acoording swimming protocol. Tumor was induced by injection of 4T1 cells. All experiments were performed in biological triplicate. After the experimental period, the tumor was removed and the cells were identified by flow cytometry with labeling to CD4, CD8, CD11c, CD11b, CD80, CD86 and Ia, and intracelular staining IL-10, IL-12, TNF-α, IFN-γ, IL-17, Tbet, GATA3, RORγt and FoxP3. The bone marrow of the animals was obtained to analyse the derivated DCs by flow cytometry and culture cells to obtain the supernatant to measure the cytokines. Our results demonstrated that the PA inhibit the tumoral growth although not to change the number of TILS, but reduced expression of GATA-3, ROR-γT, related with poor prognosis, and TNF-α intracellular; however occur one significantly reduction in TIDCS, but these cells expressed more co-stimulatory and presentation molecules. Furthermore, we observed that the induced PA stimulated the gene expression of Tbet and the production of inflammatory cytokines suggesting an increase of Th1 systemic response. The results evaluating the systemic influence in DCs showed that the PA improve significantly the number of those cells in bone marrow as well the number of co-stimulatory molecules. Therefore, we could conclude that PA influence the innate immunity by interfering to promote in process of maturation of DCs both in tumor and systemically, that by its turn promote a modification in acquired immune cells, representing by T helper to induce an important alteration transcription factors that are responsible to maintain a suppressive microenviroment, and thereby, allowing the latter cells can thus activate antitumor immune response. The PA was able improve the Th1 systemic response by enhance to Tbet gene expression, promote a slightly increased of Th1-type cytokines and decrease Gata3 and Foxp3 gene expression in which can inhibit the Th1 immune response.