Angiogenesis is a common process that is essential for tumor growth beyond 2 mm. Although numerous growth factors are involved, vascular endothelial growth factor (VEGF), particularly VEGF-A, has been shown to play an important role in tumor angiogenesis.
RNAi technology is evaluated not only as an extremely powerful instrument for functional genomic analyses but also as a potentially useful method to develop highly specific gene silencing therapeutic.
A research article to be published October 28 in the World Journal of Gastroenterology addresses the above issue. In this study, the researchers constructed vector-based expression systems in which sense and antisense strands of short VEGF sequences were transcribed into the hairpin structure under the control of the U6 promoter.
They demonstrate that siRNAs which targeted against VEGF efficiently reduced the transcript levels of VEGF mRNAs, ultimately resulting in a reduction in the levels of VEGF protein. Furthermore, this inhibition was shown to be highly selective and sequence-specific because control siRNAs had little inhibitory effects on expression and transcription of VEGF.
The researchers have further demonstrated that, in addition to the above-reported target sites in the VEGF genome, the specific 21-bp siRNAs targeting VEGF exerted efficient and specific inhibition on VEGF expression, suggesting a good method to inhibit the expression of VEGF.
Future studies will be centered on the evaluation of the anti-VEGF efficacy of RNAi vectors in valid animal models, as well as on the preclinical elucidation using the RNAi technology.
Reference: Li TJ, Song JN, Kang K, Tong SS, Hu ZL, He TC, Zhang BQ, Zhang CQ. RNA interference-mediated gene silencing of vascular endothelial growth factor in colon cancer cells. World J Gastroenterol 2007;13(40): 5312-5316
http://www.wjgnet.com/1007-9327/13/5312.asp
Correspondence to: Professor Cai-Quan Zhang, Department in General Surgery, the First Affiliated Hospital, Chongqing University of Medical Science, Chongqing 400016, China. cqltj001@163.com
Telephone: +86-23-89013259 Fax: +86-23-8901114
About World Journal of Gastroenterology
World Journal of Gastroenterology (WJG), a leading international journal in gastroenterology and hepatology, has established a reputation for publishing first class research on esophageal cancer, gastric cancer, liver cancer, viral hepatitis, colorectal cancer, and H pylori infection for providing a forum for both clinicians and scientists. WJG has been indexed and abstracted in Current Contents/Clinical Medicine, Science Citation Index Expanded (also known as SciSearch) and Journal Citation Reports/Science Edition, Index Medicus, MEDLINE and PubMed, Chemical Abstracts, EMBASE/Excerpta Medica, Abstracts Journals, Nature Clinical Practice Gastroenterology and Hepatology, CAB Abstracts and Global Health. ISI JCR 2003-2000 IF: 3.318, 2.532, 1.445 and 0.993. WJG is a weekly journal published by WJG Press. The publication dates are the 7th, 14th, 21st, and 28th day of every month. The WJG is supported by The National Natural Science Foundation of China, No. 30224801 and No. 30424812, and was founded with the name of China National Journal of New Gastroenterology on October 1, 1995, and renamed WJG on January 25, 1998.
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World Journal of Gastroenterology