Dutch biotechnology company Crucell has started a programme with Medarex of the US to evaluate the STAR technology for the production of antibodies and other proteins, acquired by the latter firm when it bought ChromaGenics in March 2004.
The STAR technology is based on the concept of epigenetics - the study of cellular factors (usually DNA and protein factors) that are involved in the regulation of gene expression.
In man, 80 to 90 per cent of genes are switched off, or silenced, because they code for proteins that are not essential for the functioning of cells. In fact, genes are silenced by default in cells, and those that need to remain active only do so because of the action of regulatory sequences.
This means that when cells are transformed with the DNA sequence required to make a protein, the most likely occurrence is that that they end up in a silent part of the genome - one of the principle reasons why creating cell lines to make proteinsis such a hit and miss affair. Crucell's solution is to use regulatory sequences - known as STAR elements - on either side of the protein-coding sequence (transgene), to create a non-silent portion of the genome.
The Medarex project aims to optimise the application of STAR in a bioreactor culture used to make a fully human antibody developed using Medarex's UltiMAb technology. Further details were not disclosed.
In January of this year, Crucell started a similar evaluation programme for the STAR technology with US biotechnology firm Genentech. And in March the Dutch firm was awarded its first patent for the technology.