Amersham Biosciences: New Study Reveals Significant Differences In Protein Expression Between Normal And Colorectal Cancer Samples Using Ettan DIGE Technology 
10/19/2005 5:10:33 PM

Vanderbilt University Medical Center Study Uncovers 52 Differences in Protein Expression between Normal and Colorectal Cancer Samples

PISCATAWAY, N.J.--(BUSINESS WIRE)--March 22, 2004-- A new study published this month in Proteomics(1) shows that two-dimensional difference gel electrophoresis (2-D DIGE) technology provided by Amersham Biosciences, the life sciences business of Amersham (LSE:, NYSE:, OSE: AHM), reveals statistically significant differences in protein abundance between normal and colorectal cancer samples that would not have been easily detected using classic 2-D gel separation. Ettan(TM) DIGE technology from Amersham Biosciences has significant benefits over classic 2-D electrophoresis, providing a very sensitive and accurate method for measuring differences in protein expression.

Researchers at Vanderbilt University Medical Center, including members of the GI SPORE, used 2-D DIGE coupled with mass spectrometry to investigate differences in protein expression between human colorectal cancers and normal mucosa. Cy(TM)5-labeled proteins isolated from the tumor tissue of six patients and Cy3-labeled proteins isolated from adjacent normal mucosa were mixed together and then separated on the same 2-D gel along with a Cy2-labeled mixture of all the samples. Comparison with the mixed sample internal standard enabled protein abundance in the tumor and normal samples to be inter-compared among six patients without interference from gel-to gel variation. Mass spectrometry and database interrogation were then used to identify those proteins that had a consistently different abundance in the tumor and normal samples

Using this method, 52 unique proteins were identified that had a statistically significant difference in abundance between tumor and normal samples. For 42 of these 52 proteins, the use of DIGE technology with a mixed sample internal standard enabled detection of protein abundance changes that would not have been evident if the Cy3-labelled and Cy5-labelled proteins from each patient had been compared separately.

"Identifying proteins that differ in abundance between normal and tumor samples may provide insight into critical events in cancer progression, or reveal proteins with potential value as therapeutic targets," said Dr David Friedman, the study's lead investigator. "DIGE technology with a mixed sample internal standard enables us to find differences in protein abundance that would otherwise be overlooked due to the large degree of variation inherent between normal and tumor samples."


(1). Friedman DB, Hill S, Keller JW, Merchant NB, Levy SE, Coffey RJ and Caprioli RM. Proteome analysis of human colon cancer by 2 dimensional difference gel electrophoresis and mass spectrometry. Proteomics 2004; 4(3): 793-811. Notes to Editors:

Ettan DIGE is a fully integrated system for 2-D difference gel electrophoresis which enables up to three protein samples to be labeled with novel CyDye(TM) fluors and co-separated on the same gel. The use of a mixed sample internal standard enables gel-to-gel variation to be eliminated, so that small (as low as 10%) differences in protein abundance between samples can be detected with greater than 95% statistical confidence. DeCyder(TM) analysis software is used for image analysis.

Amersham Biosciences, the life sciences business of Amersham (LSE: NYSE: OSE: AHM), is a world leader in developing and providing integrated systems and solutions for disease research, drug development and manufacture. Our systems are used to uncover the function of genes and proteins, for the discovery and development of drugs and for the manufacture of biopharmaceuticals. The customers for Amersham Biosciences' products and technology are pharmaceutical and biotechnology companies and research and academic institutions, principally in North America, Europe, Latin America and Asia. More information about Amersham Biosciences is available at

GI SPORE is the Gastro Intestinal Special Program Of Research Excellence, specialized program of research funded by the National Cancer Institute (NCI) of America.

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Amersham Biosciences: Europe tel: +44 (0) 1494 498 050 or CPR Worldwide, London Matthew Kent tel: +44 (0) 207 395 7133

Source: Amersham Biosciences