• Parasites, Hosts and Diseases
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• v.52 no.6
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• pp.605-612
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• 2014

Toxoplasma gondii is an intracellular protozoan parasite that causes a Th1 cellular immunity. Our previous study showed that T. gondii lysate antigen (TLA) treatment in S180 tumor-bearing mice resulted in tumor reduction by suppressing CD31 expression, a marker of angiogenesis. In the present study, to investigate tumor suppressive effect of TLA under the absence of T lymphocytes, athymic nude mice were compared with euthymic mice in the anti-tumorigenic effect triggered by TLA in CT26 tumors. According to the results, intratumorally injected TLA reduced tumor growth and TIMP-1 level, a metastatic marker, in both euthymic and athymic mice. TLA treatment led to a sharp increase in IL-12 expression in serum cytokine profiling of athymic mice, and increased MyD88 signals in macrophages derived from the bone marrow, implying the activation of innate immunity. The selective induction of IL-12 by TLA treatment had an anti-tumorigenic effect.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3815-3819
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• 2012

The CD4+CD25+ regulatory T cell (Treg) is a special kind of T cell subset. Studies have showed that Treg cells are involved in a number of physiological processes and pathologic conditions such as autoimmune diseases, transplantation tolerance and cancer. Tregs with unique capacity for immune inhibition can impair anti-tumour immunity and help tumor cells to escape from immune surveillance. The aim of our study was to investigate whether Tregs are involved in hepatocellular carcinoma (HCC). A BABL/C mouse with HCC in situ model was established to evaluate the Treg existence in carcinoma tissues and the changes of Tregs in spleen using flow cytometry and immunohistochemistry methods. Granzyme B expression in carcinoma tissues was analyzed by immunohistochemistry to investigate the tumor local immune status.The proportion of CD4+CD25+/CD4+ spleen lymphocytes of tumor bearing mice ($18.8%{\pm}1.26%$) was found to be significantly higher than that in normal mice ($9.99%{\pm}1.90%$) (P<0.01 ). Immunohistochemistry of spleen tissue also confirmed that there was an increase in Treg in tumor-bearing mice, while in carcinomas it showed Treg cells to be present in tumor infiltrating lymphocyte areas while Granzyme B was rarely observed. Anti-tumour immunity was suppressed, and this might be associated with the increase of Tregs. Our observations suggest that the CD4+CD25+Treg/CD4+ proportion in spleen lymphocytes can be a sensitive index to evaluate the change of Tregs in hepatocellular carcinoma mice and the Treg may be a promising therapeutic target for cancer.

• BMB Reports
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• v.43 no.12
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• pp.773-780
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• 2010

Cancers are still difficult targets despite recent advances in cancer therapy. Due to the heterogeneity of cancer, a single-treatment modality is insufficient for the complete elimination of cancer cells. Therapeutic strategies from various aspects are needed. Gene therapy has been expected to bring a breakthrough to cancer therapy, but it has not yet been successful. Gene therapy also should be combined with other treatments to enhance multiple therapeutic pathways. In this view, gene delivery vector itself should be equipped with intrinsic anti-cancer activities. HVJ (hemagglutinating virus of Japan; Sendai virus) envelope vector (HVJ-E) was developed to deliver therapeutic molecules. HVJ-E itself possessed anti-tumor activities such as the generation of anti-tumor immunities and the induction of cancer-selective apoptosis. In addition to the intrinsic anti-tumor activities, therapeutic molecules incorporated into HVJ-E enabled to achieve multi-modal therapeutic strategies in cancer treatment. Tumor-targeting HVJ-E was also developed. Thus, HVJ-E will be a novel promising tool for cancer treatment.

• Genomics & Informatics
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• v.13 no.2
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• pp.26-30
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• 2015

nc886 (=vtRNA2-1, pre-miR-886, or CBL3) is a newly identified non-coding RNA (ncRNA) that represses the activity of protein kinase R (PKR). nc886 is transcribed by RNA polymerase III (Pol III) and is intriguingly the first case of a Pol III gene whose expression is silenced by CpG DNA hypermethylation in several types of cancer. PKR is a sensor protein that recognizes evading viruses and induces apoptosis to eliminate infected cells. Like viral infection, nc886 silencing activates PKR and induces apoptosis. Thus, the significance of the nc886:PKR pathway in cancer is to sense and eliminate pre-malignant cells, which is analogous to PKR's role in cellular innate immunity. Beyond this tumor sensing role, nc886 plays a putative tumor suppressor role as supported by experimental evidence. Collectively, nc886 provides a novel example how epigenetic silencing of a ncRNA contributes to tumorigenesis by controlling the activity of its protein ligand.

• IMMUNE NETWORK
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• v.24 no.1
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• pp.5.1-5.19
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• 2024

The key role of T cells in cancer immunotherapy is well established and is highlighted by the remarkable capacity of Ab-mediated checkpoint blockade to overcome T-cell exhaustion and amplify anti-tumor responses. However, total or partial tumor remission following checkpoint blockade is still limited to only a few types of tumors. Hence, concerted attempts are being made to devise new methods for improving tumor immunity. Currently, much attention is being focused on therapy with IL-2. This cytokine is a powerful growth factor for T cells and optimises their effector functions. When used at therapeutic doses for cancer treatment, however, IL-2 is highly toxic. Nevertheless, recent work has shown that modifying the structure or presentation of IL-2 can reduce toxicity and lead to effective anti-tumor responses in synergy with checkpoint blockade. Here, we review the complex interaction of IL-2 with T cells: first during normal homeostasis, then during responses to pathogens, and finally in anti-tumor responses.

• IMMUNE NETWORK
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• v.9 no.5
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• pp.147-152
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• 2009

Ascorbate (vitamin C) is a cofactor for a number of metabolic enzymes and is an indisputable essential vitamin C for humans. However, the potential of ascorbate as an anticancer agent has been a topic of controversy. A number of previous reports have addressed both positive aspects and limitations of ascorbate in cancer therapy. In this review, we briefly summarize the potential antitumor effects of ascorbate and its prospects for clinical use.

• IMMUNE NETWORK
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• v.9 no.4
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• pp.122-126
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• 2009

Transforming growth factor-$\beta$ (TGF-$\beta$) is a highly pleiotropic cytokine playing pivotal roles in immune regulation. TGF-$\beta$ facilitates tumor cell survival and metastasis by targeting multiple cellular components. Focusing on its immunosuppressive functions, TGF-$\beta$ antagonists have been employed for cancer treatment to enhance tumor immunity. TGF-$\beta$ antagonists exert anti-tumor effects through #1 activating effector cells such as NK cells and cytotoxic $CD8^+$ Tcells (CTLs), #2 inhibiting regulatory/suppressor cell populations, #3 making tumor cells visible to immune cells, #4 inhibiting the production of tumor growth factors. This review focuses on the effect of TGF-$\beta$ on T cells, which are differentiated into effector T cells or newly identified tumor-supporting T cells.

• IMMUNE NETWORK
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• v.4 no.4
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• pp.205-215
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• 2004

In the early host defense system, effector function of natural killer (NK) cells results in natural killing against target cells such as microbe-infected, malignant, and certain allogenic cells without prior stimulation. NK cell cytotoxicity is selectively regulated by homeostatic prevalence between a repertoire of both activating and inhibitory receptors, and the discrimination of untransformed cells is achieved by recognition of major histocompatibility complex (MHC) class I alleles through inhibitory signals. Although it is well known that the bipotential T/NK progenitors are derived from the common precusor, functional mechanisms in terms of the development of NK cells remain to be further investigated. NK cells are mainly involved in innate immunity, but recent studies have been reported that they also play a critical role in adaptive immune responses through interaction with dendritic cells (DC). This interaction will provide effector functions and development of NK cells, and elucidation of its precise mechanism may lead to therapeutic strategies for effective treatment of several immune diseases.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.1
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• pp.26-37
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• 2008

Objective : The present study was carried out to investigate the effects of NaisoOkseol-Tang (NOT) on solid tumor in mice in terms of immune-potentiating and direct cytotoxic action of NOT in vitro and vivo study. Methods: The present author investigated thymocyte proliferation and NO production to confirm immune-potentiating activity of NOT and also investigated body/tumor weight and survival rates in tumor bearing mice. In this study, administration of NOT decreased tumor/weight ratio significantly, and prolonged survival duration compared to non-treated control. Treatment with NOT also elevated proliferation rates of thymocytes isolated from tumor bearing mice. Results: In vitro study, treatment with NOT suppressed proliferation rate of Sarcoma 180 (S-180) cells. Contrary, treatment with NOT elevated proliferation rate of thymocytes. These results were co-related with in vivo study. In addition, NO production from abdominal macrophages isolated from normal mice was not affected by treatment with NOT. Conclusion : NOT is useful to treat patient with solid tumor, because NOT has direct toxic action for tumor cell and immune-potentiating action for T cells.

• Journal of Ginseng Research
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• v.18 no.3
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• pp.151-159
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• 1994

To evaluate the anticarcinogenic effect and its mechanism of red ginseng, the mice were treated with red ginseng and received subcutaneous Bl6 melanoma cell line injection on the back. Tumor incidence was same (100%) both in water and red ginseng-treated groups, but tumor production was delayed in red ginseng-treated group. Survival time was somewhat longer in red ginseng-treated group. The histopathological findings were similar in both groups, but lymphocytic infiltration around the tumor and melanin production in the tumor cells were prominent in the red ginseng-treated group. Flow cytometric analysis on T lymphocytes and natural killer cells revealed increased $T_H$/$T_S$ ratio and increased NK cells in red ginseng-treated group. These results suggest that the anticarcinogenic effect of red ginseng may be exerted by the increased cell-mediated immunity and natural killer cell activity.