• Molecules and Cells
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• 제41권7호
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• pp.653-664
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• 2018

The RNA-binding protein tristetraprolin (TTP) binds to adenosine-uridine AU-rich elements in the 3'-untranslated region of messenger RNAs and facilitates rapid degradation of the target mRNAs. Therefore, it regulates the expression of multiple cancer and immunity-associated transcripts. Furthermore, a lack of TTP in cancer cells influences cancer progression and predicts poor survival. Although the functions of TTP on cancer cells have previously been researched, the mechanism of TTP on the interaction between cancer cells with their micro-environment remains undiscovered. In this study, we admed to determine the role of cancer cell TTP during the interaction between tumor and immune cells, specifically regulatory T cells (Tregs). We evaluate the capability of TTP to modulate the antitumor immunity of GC and explored the underlying mechanism. The overexpression of TTP in GC cells dramatically increased peripheral blood mononuclear lymphocyte (PBML) -mediated cytotoxicity against GC cells. Increased cytotoxicity against TTP-overexpressed GC cells by PBMLs was determined by Treg development and infiltration. Surprisingly, we found the stabilization of programmed death-ligand 1 (PD-L1) mRNA was declining while TTP was elevated. The PD-L1 protein level was reduced in TTP-abundant GC cells. PD-L1 gas been found to play a pivotal role in Treg development and functional maintenance in immune system. Taken together, our results suggest the overexpression of TTP in GC cells not only affects cell survival and apoptosis but also increases PBMLs -mediated cytotoxicity against GC cells to decelerate tumor progression. Moreover, we identified PD-L1 as a critical TTP-regulated factor that contributes to inhibiting antitumor immunity.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.117-121
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• 1999

The anititumor and immunologic activities of the glycoproteins extracted from sea cucumber (Stichopus japonicus) on mice bearing sarcoma 180 cells were investigated . Maximum tumor suppression (64%) occurred at the dose of 100mg glycoprotein/kg. The highest prolongation ratio was achieved at the level of 100mg/kg an dincreased by 395 more than that of control. Glycoproteins from sea cucumber exhibited direct cytotoxic effect on the tumor cells. Dose dependent increase of leucocyte, peritoneal exudate cell and weights of immunoorgans revealed the improvement of immunity. When the glycoportein-administered group was compared with the control, a significant difference was not noted in the clinico-chemical values such as S-GOT, S-GPT , alkaline phoshatse activity, total protein, cholesterol, triglyceride, urea nitrogen and glucose levels in blood. These results suggests that the antitumor activity of sea cucumber glycoprotein is associated with activation of cells in the immune system.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 공동 춘계학술대회
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• pp.68.2-68
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• 1999

No Abstract, See Full Text

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 춘계총회 및 학술대회
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• pp.145.2-145.2
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• 2000

• 생약학회지
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• 제29권2호
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• pp.110-119
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• 1998

Sa-Mul-Tang(SMT) consist of Rehmanniae Radix Preparata, Paeoniae Radix Alba, Cnidii Rhizoma and Angelicae Gigantis Radix. In L1210 cells-transplanted BALB/c mice, T-lymphocyte apoptosis, $CD8^+T_C$ cells population in thymocyte and nitric oxide production in macrophage were enhanced, but phagocytic activity was decreased. SMT suppressed T-lymphocyte apoptosis and enhanced CD^4+T_H$ cells population, but did not affect nitric oxide production and phagocytic activity in L1210 cells-transplanted mice. In antitumor drugs-injected mice, T-lymphocyte apoptosis was enhanced, but $CD4^+T_H/CD8^+T_C$, cells population and T-lymphocyte proliferation were decreased. SMT suppressed T-lymphocyte apoptosis, and enhanced $CD8^+T_C$ cells population, T-lymphocyte proliferation and phagocytic activity in vincristine-injected mice. These results suggest that SMT enhances T cell-mediated immunity in L1210 cell-transplanted mice, and enhances T cell-mediated immunity and phagocytic activity in vincristine-injected mice.

• BMB Reports
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• 제50권5호
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• pp.263-268
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• 2017

${\beta}$-Agarase cleaves the ${\beta}$-1,4 linkages of agar to produce neoagarooligosaccharides (NAO), which are associated with various physiological functions. However, the immunological functions of NAO are still unclear. In this study, we demonstrated that ${\beta}$-agarase DagA-produced neoagarohexaose (DP6), an NAO product, promoted the maturation of dendritic cells (DCs) by Toll-like receptor 4 (TLR4). DP6 directly and indirectly enhanced the activation of natural killer (NK) cells in a TLR4-dependent manner in vitro and in vivo. Finally, the antitumor activity of DP6 against B16F1 melanoma cells was inhibited in NK cell-depletion systems by using NK-cell depleting antibodies in vivo. Collectively, the results indicated that DP6 augments antitumor immunity against B16F1 melanoma cells via the activation of DC-mediated NK cells in a TLR4-dependent manner. Thus, DP6 is a potential candidate adjuvant that acts as an immune cell modulator for the treatment of melanoma.

• 한국식품위생안전성학회지
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• 제4권2호
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• pp.109-118
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• 1989

한국산 담자균류인 갓버섯 Lepiota procera의 균사를 액내 배양하여 항암성분인 단백성 다당체를 분리하였다. 이 성분은 DEAE-Sephadex A-50 이온교환수지와 Sepharose-4B gel Filtration을 이용하여 정제하여 Fraction C1을 얻었으며 이 Fr, Cr은 단백질과 다당체로 구성되어 있으며 항암 효과는 10mg/kg/day 투여군에서 64%의 저지유을 나타내었다. 이러한 항암작용의 기전을 밝히기 위한 연구의 일환으로 면역에 미치는 영향을 실험함 결과 이 단백다당체는 용혈반형성 세포수를 증가시켰으며, 저하된 지연성 과민반응을 회복시켰을 뿐만 아니라, carrageenan 투여에 의해 억제된 면역능을 다시 증강시켰음을 알 수 있었다. 이러한 결과들은 이 버섯의 항암작용이 세포독성에 의한 것이 아니라 종양에 대한 면역능을 강화시켜 발휘됨을 제시하고 있다.

• 생약학회지
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• 제38권2호통권149호
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• pp.117-122
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• 2007

The specific activation of the immune system to control cancer growth in vivo has been a long-standing goal in cancer immunology. Whole tumor Iysates have been used either alone or combined with adjuvants to induce specific immune response in vivo. Here, we examined whether freezing/thawing (F/T) colon26-M3.1 tumor cell admixed with EN-3, glycoprotein purified from Acanthopanx Senticosus, could stimulate in vivo immunity by using a murine experimental tumor metastasis model produced by colon26-M3.1 carcinoma cells. Vaccination of mice with F/T treated colon26-M3.1 carcinoma cells in combination with EN-3 as an adjuvant resulted in a significant inhibition in tumor metastasis of mice against live colon26-M3.1 carcinoma challenge. In addition, the splenocytes from vaccinated mice exhibited a higher proliferating activity and secreted interferon-${\gamma}$. These results suggest that EN-3 can be applied to immunoadjuvant to enhance the antitumor immunity in vivo.

• IMMUNE NETWORK
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• 제11권4호
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• pp.210-215
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• 2011

It is already known that high concentration of vitamin C induces apoptosis on tumor cells. However, there is no report regarding the function of vitamin C on the modulation of immune susceptibility of cancer. Therefore, we investigated whether vitamin C can modulate immune susceptibility of tumor cells, especially on the induction of Fas-mediated apoptosis. First, the optimal concentration of vitamin C, which cannot induce damages on tumor cells for 36 hrs. We found that 2 mM of vitamin C did not show harmful effect. In addition, the optimal concentration of agonistic anti-Fas Abs for 18 hrs was examined. As a result, 400 ng/ml of agonistic anti-Fas Abs did not induce apoptosis on tumor cells. Next, we tried to find the effect of 2 mM of vitamin C on the modulation of the susceptibility to agonistic anti-Fas Abs. When tumor cells were cultured with 400 ng/ml of agonistic anti-Fas Abs for 18 hrs, after pre-treatment with 2 mM of vitamin C for 24 hrs, viability of cells was decreased. Interestingly, we found that the expression of Fas (CD95) and MHC class I was increased by the treatment of vitamin C. Taken together, vitamin C increases the susceptibility of tumor cells to anti-Fas Abs and the expression of Fas (CD95) and MHC class I on tumor cells.

• Archives of Pharmacal Research
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• 제2권2호
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• pp.145-151
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• 1979

The carpophores of three Korean mushrooms, Coriolus versicolor, Pleurotus ostreatus and Lentinus edodes were respectively extracted with hot water and the extracts were dialyzed through Visking tube. They were found to exert an antitumor activity against sarcoma-180 implanted in mice. Especially, the inhibition ratio of the extract of Coriolus versicolor (100 mg/ Kg.i.p) was almost 100% . But all the extracts did not affect the growth of leukemia L517Y cells in vitro. Therefore these facts indicate that the extracts appear to stimulate cell-mediated immunity.