Basic Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2005; 11(45): 7104-7108
Published online Dec 7, 2005. doi: 10.3748/wjg.v11.i45.7104
A novel gain of function mutant in C-kit gene and its tumorigenesis in nude mice
Chen-Guang Bai, Xiao-Hong Liu, Qiang Xie, Fei Feng, Da-Lie Ma
Chen-Guang Bai, Qiang Xie, Fei Feng, Da-lie Ma, Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Xiao-Hong Liu, Institute of Thoracic Cardiac Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 30070743 and No. 30471702
Correspondence to: Da-Lie Ma, Professor of Department of Pathology, Changhai Hospital, Second Military Medical University, Changhai Road, Shanghai 200433, China. madalie@126.com
Telephone: +86-21-25074851 Fax: +86-21-25070660
Received: April 15, 2005
Revised: June 2, 2005
Accepted: June 6, 2005
Published online: December 7, 2005
Abstract

AIM: To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor (GIST).

METHODS: Eukaryotic expression vectors of pcDNA3-Kit-NW and pcDNA3-Kit-W were constructed. Then pcDNA3-Kit-NW and pcDNA3-Kit-W plasmids were transfected into human embryonic kidney cell line by Lipofectamine. The resistant clone was screened by G418 filtration and identified by sequencing, Western blotting, and immunocytochemical staining. Human embryonic kidney cells were divided into three groups including pcDNA3-Kit-NW, pcDNA3-Kit-W, and vector control groups. Absorbency value with a wavelength of 574 nm was detected by MTT analysis. Mice were injected with three groups of cells. Volume, mass, and histological examinations of the tumors in different groups were measured and compared.

RESULTS: The C-kit gene and mutant C-kit gene were successfully cloned into the eukaryotic expression vector pcDNA3. pcDNA3-Kit-NW and pcDNA3-Kit-W were successfully transfected into human embryonic kidney cell line and showed stable expression in this cell line. Cell proliferating activity had significant differences between pcDNA3-Kit-NW and pcDNA3, pcDNA3-Kit-NW and pcDNA3-Kit-W (P<0.05), respectively. Tumors were only observed in nude mice implanted with cells transfected with pcDNA3-Kit-NW.

CONCLUSION: Mutation of C-kit gene increases the proliferation activity of human cells and plays an important role in the malignant transformation of GIST.

Keywords: Gastrointestinal stromal tumors; Protooncogene C-kit; Gene mutation; Malignant transformation