김현주, 정선용 임규빈 2017-08 26016 https://aurora.ajou.ac.kr/handle/2018.oak/19099 학위논문(석사)--아주대학교 일반대학원 :의생명과학과,2017. 8 I. INTRODUCTION 1 II. MATERIALS AND METHODS 7 A. Tumor tissue samples 7 B. Primary tissue-cultured cells and cell lines 7 C. Hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) 8 D. Plasmid constructs and small interfering RNAs (siRNAs) 9 E. Reverse transcription-PCR (RT-PCR) 10 F. Western blot analysis 10 G. Ras activation assay 11 H. Cell viability assay 12 III. RESULTS 14 A. Downregulation of IFITM1 in MPNST tissues of patients with NF1 14 B. Downregulation of IFITM1 in MPNST cells from NF1 patients and MPNST cell lines 17 C. Correlation of IFITM1 expression and Ras activation levels in primary MPNST cells and MPNST cell lines 19 D. Effects of interferon-γ on enhancing IFITM1 expression and reducing Ras and Erk1/2 activation in MPNST cells 21 E. Sensitization effects of interferon-gamma on enhancing cytotoxicity of the MPNST cells co treated with cisplatin and gemcitabine 23 IV. DISCUSSION 26 V. CONCLUSION 29 REFERENCES 30 국문요약 37 eng The Graduate School, Ajou University 아주대학교 논문은 저작권에 의해 보호받습니다. 제1형 신경섬유종증의 종양 악성화에 관여하는 IFITM1 유전자의 역할 The role of IFITM1 in malignant progression of neurofibromas in NF1 Thesis 아주대학교 일반대학원 일반대학원 의생명과학과 2017. 8 Master http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000026016 NF1 IFITM1 Neurofibromatosis type 1 (NF1) is one of the most commonly inherited autosomal dominant human genetic disorder with an incidence of approximately 1 in 3000~3500 individuals worldwide. NF1 is caused by loss-of-function mutations in the NF1 gene encoding neurofibromin, a GTPase-activating protein. Because the pathogenesis of the tumor progression of benign plexiform neurofibromas (PNs) to malignant peripheral nerve sheath tumors (MPNSTs) remained unclear, genetic and epigenetic changes involved in MPNST pathogenesis. Here I found that interferon-induced transmembrane protein 1 (IFITM1) was downregulated in MPNST tissues compared to that in PN tissues from NF1 patients by immunohistological staining and/or Western blot analysis. Overexpression of IFITM1 in the NF1-deficient MPNST tumor cells resulted in a decrease in Ras activation (GTP-Ras), while downregulation of IFITM1 by treatment of small interfering RNA in normal-phenotypic NF1-deficient cells caused an increase in Erk1/2 activation (phosphorylated Erk1/2), indicating that expression level of IFITM1 is closely related with tumor progression in NF1. Treatment of interferon-γ (INF-γ) in the MPNST cells caused elevated expression of IFITM1, thereby leading to a decrease in the Ras activation and its downstream Erk1/2 activation. Notably, INF-γ produced a sensitization effect on enhancing cytotoxicity of MPNST cells by cotreatment of low-dose cisplatin and gemcitabine. These results provide a new potential target for chemotherapy in the NF1 patients with MPNSTs.