Functional Defect of the Fas Mutants Detected in Gastric Cancers

위암에서 발견된 돌연변이형 Fas 단백의 기능적 결함

  • Park Won Sang (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Cho Young Gu (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Kim Chang Jae (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Park Cho Hyun (Departments of Surgery, College of Medicine, The Catholic University of Korea) ;
  • Kim Young Sil (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Kim Su Young (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Nam Suk Woo (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Lee Sug Hyung (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Yoo Nam Jin (Departments of Pathology College of Medicine, The Catholic University of Korea) ;
  • Lee Jung Young (Departments of Pathology College of Medicine, The Catholic University of Korea)
  • 박원상 (가톨릭대학교 의과대학 병리학교실) ;
  • 조용구 (가톨릭대학교 의과대학 병리학교실) ;
  • 김창재 (가톨릭대학교 의과대학 병리학교실) ;
  • 박조현 (가톨릭대학교 의과대학 외과학교실) ;
  • 김영실 (가톨릭대학교 의과대학 병리학교실) ;
  • 김수영 (가톨릭대학교 의과대학 병리학교실) ;
  • 남석우 (가톨릭대학교 의과대학 병리학교실) ;
  • 이석형 (가톨릭대학교 의과대학 병리학교실) ;
  • 유남진 (가톨릭대학교 의과대학 병리학교실) ;
  • 이정용 (가톨릭대학교 의과대학 병리학교실)
  • Published : 2003.12.01

Abstract

Purpose: The balance between cell proliferation and apoptosis is crucial for homeostatic maintenance in a cell population. Decreased apoptosis or uncontrolled proliferation can lead to cancer. The Fas receptor signal through a cytoplasmic death domain is very important in the apoptotic pathway. To identify the effect of the death domain of the Fas gene in the development and/or progression of gastric cancer, we examined the apoptotic potential of five known Fas mutants detected in gastric cancers. Materials and Methods: A wild-type Fas gene was cloned with cDNA from normal liver tissue and full length Fas was sequenced. Mutants of the gene were generated with sitedirected mutagenesis by using the wild-type gene and specific primers. Wild- and mutant-type genes were transfected to HEK293 cells. Forty-eight hours after transfection the cells were stained with DAPI and cell death was counted under fluorescent microscopy. Results: In wild-type Fas-transfected cells, the percentage of apoptotic cells was $85.9\pm3.6\%$, and significant cell death and classic morphologic signs of apoptosis were observed. However, the percentages of apoptotic cells transfected with N239D, E240G, D244V, and R263H of tumor-derived mutant Fas were $29.5\pm2.08\%,\;28.5\pm3.34\%,\;25.225\pm2.06\%,\;and\;36.625\pm4.49\%$, respectively. Conclusion: These results suggest that inactivation of Fas caused by mutations in the death domain of the Fas gene may be one of the possible escape mechanisms against Fas-mediated apoptosis and that inactivating mutation of the Fas may contribute to the development or progression of gastric cancers.

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