• Bulletin of Food Technology
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• v.23 no.4
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• pp.535-543
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• 2010

장관은 우리 몸에서 가장 넓은 표면적을 가지고 있으며, 외부로부터 침입하는 이물에 대항하여 면역세포의 배치가 필수적이다. 항원과 만난 적이 없는 naive lymphocyte는 임파절 등 2차 임파기관의 수지세포(dendritic cell)가 임파구에 항원을 제시할 때 레티노인산(retinoic acid)을 생산하여 제공함으로써, 소장 조직에 특이적으로 임파구가 호밍(homing)하는 능력을 부여한다. 한편, 장에 있어서는 식품항원에 대한 면역반응을 억제할 필요가 있는데, RA는 T세포의 기능분화를 억제하여 면역관용의 성립에도 관여함이 밝혀졌다.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.211-218
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• 2010

Purpose: All-trans retinoic acid (ATRA) has anti proliferative effects against brain tumor cells. Recently, ATRA has been reported to induce catalase. We investigated whether catalase induction by ATRA is associated with its anti proliferative effects. Materials and Methods: 36B10 cells were exposed to 0~50${\mu}M$ ATRA for 24 or 48 hours and mRNA, protein, and activity of catalase were measured. Reactive oxygen species (ROS) were measured using 2',7'-dichlorofluorescin diacetate. A clonogenic assay was used to confirm the cytotoxic effect. Results: The mRNA, protein, and activity of catalase were found to increase in a concentration- and incubationtime-dependent manner. The increase in catalase activity induced by ATRA was decreased by the addition of 3-amino-1,2,4-triazole (ATZ). ROS was also increased with ATRA and decreased by the addition of ATZ. The decrease in cell survival induced by ATRA was partly rescued by ATZ. Conclusion: Catalase induction by ATRA is involved in ROS overproduction and thus inhibits the proliferation of 36B10 cells.

• Radiation Oncology Journal
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• v.23 no.4
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• pp.211-216
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• 2005

Purpose: It has been reported that all-trans retinoic acid (ATRA) can inhibit glioma growing in vitro. However, clinical trials with ATRA alone in gliomas revealed modest results. ATRA has been shown to increase radiosensitivity in other tumor types, so combining radiation and ATRA would be one of alternatives to increase therapeutic efficacy in malignant gliomas. Thus, we intended to know the role of catalase, which is induced by ATRA, for radiosensitivity if radiation-reduced reactive oxygen species (ROS) is removed by catalase, the effect of radiation will be reduced. Materials and Methods: A rat glioma cell line (36B10) was used for this study. The change of catalase activity and radiosensitivity by ATRA, with or without 3-amino-1, 2, 4-triazole (ATZ), a chemical inhibitor of catalase were measured. Catalase activity was measured by the decomposition of $H_2O_2$ spectrophotometrically Radiosensitivity was measured with clonogenic assay. Also ROS was measured using a 2, 7-dichlorofluorescein diacetate spectrophotometrically. Results: When 36B10 cells were exposed to 10, 25 and $50{\mu}M$ of ATRA for 48 h, the expression of catalase activity were increased with increasing concentration and incubation time of ATRA. Catalase activity was decreased with increasing the concentration of AT (1, $10{\mu}M$) dose-dependently. ROS was increased with ATRA and it was augmented with the combination of ATRA and radiation. ATZ decreased ROS production and increased cell survival in combination of ATRA and radiation despite the reduction of catalase. Conclusion: The increase of ROS is one of the reasons for the increased radiosensitivity in combination with ATRA. The catalase that is induced by ATRA doesn't decrease ROS production and radiosensitivity.