Abstract. Certain microRNAs (miRNAs) play a key role in cancer cell chemoresistance. However, the pleiotropic functions of exosome-derived miRNAs on developing chemoresistance remain unknown. In the present study, we aimed to construct potential networks of miRNAs, which derived from the exosome of chemoresistant prostate cancer (PCa) cells, with their known target genes using miRNA expression profiling and bioinformatic tools. Global miRNA expression profiles were measured by microarray. Twelve miRNAs were initially selected and validated by qRT-PCR. Known targets of deregulated miRNAs were utilized using DIANA-TarBase database v6.0. The incorporation of deregulated miRNAs and target genes into KEGG pathways were utilized using DIANA-mirPath software. To construct potential miRNA regulatory networks, the overlapping parts of miRNAs and their targer genes from the selected KEGG pathway 'PCa progression (hsa05215)' were visualized by Cytoscape software. We identified 29 deregulated miRNAs, including 19 upregulated and 10 downregulated, in exosome samples derived from two kinds of paclitaxel resistance PCa cells (PC3-TXR and DU145-TXR) compared with their parental cells (PC3 and DU145). The enrichment results of deregulated miRNAs and known target genes showed that a few pathways were correlated with several critical cell signaling pathways. We found that hub hsa-miR3176, -141-3p, -5004-5p, -16-5p, -3915, -488-3p, -23c, -3673 and -3654 were potential targets to hub gene androgen receptor (AR) and phosphatase and tensin homolog (PTEN). Hub gene T-cell factors/lymphoid enhancer-binding factors 4 (TCF4) target genes were mainly regulated by hub hsa-miR-32-5, -141-3p, -606, -381 and -429. These results may provide a linkage between PCa chemoresistance and exosome regulatory networks and thus lead us to propose that AR, PTEN and TCF4 genes may be the important genes which are regulated by exosome miRNAs in chemoresistance cancer cells.

Cryptotanshinone (CPT), is a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miotiorrhiza bunge. Numerous researchers have found that it could work as a potent antitumor agent to inhibit tumor growth in vitro, buith there has been much less emphasis on its in vivo role against breast tumors. Using a mouse tumor model of MCF7 cells, we showed that CPT strongly inhibited MCF7 cell growth in vivo with polarization of immune reactions toward Th1-type responses, stimulation of naive CD4+ T cell proliferation, and also increased IFN-γ and perforin production of CD4+ T cells in response to tumor-activated splenocytes. Furthermore, data revealed that the cytotoxic activity of CD4+ T cells induced by CPT was markedly abrogated by concanamycin A(CMA), a perforin inhibitor, but not IFN-γ Ab. On the other hand, after depletion of CD4+ T cells or blocked perforin with CMA in a tumor-bearing model, CPT could not effectively suppress tumor growth, but this phenomenon could be reversed by injecting naive CD4+ T cells. Thus, our results suggested that CPT mainly inhibited breast tumor growth through inducing cytotoxic CD4+ T cells to secrete perforin. We further found that CPT enhanced perforin production of CD4+ T cells by up-regulating JAK2 and STAT4 phosphorylation. These findings suggest a novel potential therapeutic role for CPT in tumor therapy, and demonstrate that CPT performs its antitumor functions through cytotoxic CD4+ T cells.

The adaptive immune response against hepatocellular carcinoma (HCC) could be a therapeutic target to restrain HCC initiation and growth. The interactions between hepatoma cells and immune cells modify the anti-tumor immunity to influence hepatoma cell survival. To explore the potential interplay between hepatoma cells and anti-HCC T-cells, we conducted a HCC induction mouse model to analyze the phenotypic and functional alterations of T-cell subsets. We found that both hepatoma tissues and hepatoma cell lines substantially produced higher leptin, which is an adipokine usually expressed in fat tissue, than normal liver tissue or hepatocytes. We also found that regulatory T-cells (Tregs), effector CD4(+) T-cells and CD8(+) T-cells upregulated expression of leptin receptor (LEPR) in spleens and livers after HCC induction. In vitro study showed that macrophages and dendritic cells isolated from HCC livers upregulated LEPR expression on T-cells. Leptin inhibited Treg activation and function in vitro, demonstrated by lower expression of TGF-β, IL-10, CTLA4 and GITR in Tregs, as wells weaker suppression of CD8(+) T-cell proliferation and production of cytotoxic mediators. In addition, silencing LEPR in Tregs favored tumor growth in a hepatoma cell line allograft model. Taken together, our study suggests that hepatoma cells could enhance anti-HCC immunity through secreting leptin to down-regulate Treg activity and subsequently promote CD8(+) T-cell response.

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ABSTRACT. In this study, the functions and mechanisms of γ δ T cells were analyzed in patients infected with Helicobacter pylori. Peripheral blood was collected from gastritis patients in the Gastroenterology Department of Ningbo No. 2 Hospital. Preliminary analyses revealed 24 H. pylori-positive and 17 H. pylori-negative patients. The wild-type and γ δ T knockout mice were infected with cultured H. pylori cells (obtained from the H. pylori-positive patients). H. pylori in mice was quantified by polymerase chain reaction; gastritis was confirmed by hematoxylin and eosin staining. The TCR-δ -/-mice were treated with vein adoptive immunotherapy 24 h prior to H. pylori inoculation; the same method was used to detect the extent of gastritis and bacterial colonization. The γ δ T knockout mice showed high levels of H. pylori infection than the wild-type mice; in addition, the knockout mice showed severe disease pathology. γ δ T knockout mice also displayed increased matrix metalloproteinase-9 (MMP-9) and decreased MMP-7 expression in the gastric mucosa. γ δ T cells play a protective role in patients infected with H. pylori. γ δ T cell [responsible for the production of interleukin-17 (IL-17) and IL-22] expression was increased in H. 10544T.E. Chen et al. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 10543-10552 (2015) pylori-positive patients, indicating statistical significance. However, there was no significant difference in interferon-gamma + γ δ T expression between the positive and negative patients. This study demonstrated the probable involvement of γ δ T cells in the immune response of an organism, via the secretion of IL-17 and IL-22.