Expression profile and down-regulation of argininosuccinate synthetase in hepatocellular carcinoma in a transgenic mouse model

CCUR > College of Environmental Planning & Bioresources > College of Agriculture > Department of Animal Science > monograph > Item 987654321/30860

Please use this identifier to cite or link to this item: https://irlib.pccu.edu.tw/handle/987654321/30860

Title:	Expression profile and down-regulation of argininosuccinate synthetase in hepatocellular carcinoma in a transgenic mouse model
Authors:	Shiue, Shih-Chang Huang, Miao-Zeng Tsai, Ting-Fen Chang, Alice Chien Choo, Kong Bung Huang, Chiu-Jung Su, Tsung-Sheng
Contributors:	Dept Anim Sci
Keywords:	Argininosuccinate synthetase Transgenic mouse model Hepatocellular carcinoma Embryo expression map Brain expression map Ventricular zone Subventricular zone Post-transcriptional regulation Bacterial artificial chromosome GFP reporter gene
Date:	2015-01
Issue Date:	2015-11-03 15:48:03 (UTC+8)
Abstract:	Background: Argininosuccinate synthetase (ASS) participates in urea and nitric oxide production and is a rate-limiting enzyme in arginine biosynthesis. Regulation of ASS expression appears complex and dynamic. In addition to transcriptional regulation, a novel post-transcriptional regulation affecting nuclear precursor RNA stability has been reported. Moreover, many cancers, including hepatocellular carcinoma (HCC), have been found not to express ASS mRNA; therefore, they are auxotrophic for arginine. To study when and where ASS is expressed and whether post-transcriptional regulation is undermined in particular temporal and spatial expression and in pathological events such as HCC, we set up a transgenic mouse system with modified BAC (bacterial artificial chromosome) carrying the human ASS gene tagged with an EGFP reporter. Results: We established and characterized the transgenic mouse models based on the use of two BAC-based EGFP reporter cassettes: a transcription reporter and a transcription/post-transcription coupled reporter. Using such a transgenic mouse system, EGFP fluorescence pattern in E14.5 embryo was examined. Profiles of fluorescence and that of Ass RNA in in situ hybridization were found to be in good agreement in general, yet our system has the advantages of sensitivity and direct fluorescence visualization. By comparing expression patterns between mice carrying the transcription reporter and those carrying the transcription/post-transcription couple reporter, a post-transcriptional up-regulation of ASS was found around the ventricular zone/subventricular zone of E14.5 embryonic brain. In the EGFP fluorescence pattern and mRNA level in adult tissues, tissue-specific regulation was found to be mainly controlled at transcriptional initiation. Furthermore, strong EGFP expression was found in brain regions of olfactory bulb, septum, habenular nucleus and choroid plexus of the young transgenic mice. On the other hand, in crossing to hepatitis B virus X protein (HBx)-transgenic mice, the Tg (ASS-EGFP, HBx) double transgenic mice developed HCC in which ASS expression was down-regulated, as in clinical samples. Conclusions: The BAC transgenic mouse model described is a valuable tool for studying ASS gene expression. Moreover, this mouse model is a close reproduction of clinical behavior of ASS in HCC and is useful in testing arginine-depleting agents and for studies of the role of ASS in tumorigenesis.
Relation:	JOURNAL OF BIOMEDICAL SCIENCE 卷: 22 文獻號碼: 10
Appears in Collections:	[Department of Animal Science] monograph

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	494	View/Open

View Licence

Loading...