World's first rat embryonic stem cells

Can transgenic rats aid drug discovery?

Martin Harvey/Getty Images

In what is believed to be a world first, germ-line transmission from embryonic stem cells in rats has been achieved, which will enable the creation of transgenic rats. The full scientific reports on this breakthrough have been independently verified and submitted to a major scientific journal for publication.

The work was conducted by Stem Cells Sciences (UK), which exclusively licensed the technology that made the achievement possible from Edinburgh University (UK). The company plans to engage in confidential discussions with interested parties seeking a sublicence to use rat embryonic stem cells in their commercial drug discovery programmes.

"This remarkable breakthrough will enable the generation of transgenic rat models for drug discovery in a very similar manner to the already widely used transgenic mice models," says Alastair Riddell, CEO of Stem Cell Sciences. "The advantage is that rats are viewed as more predictable human models than mice for several psychiatric neurological and cardiovascular drug targets. The ability to knock-in human genes should also enable drug metabolism studies to be undertaken with higher predictability in rats than previously available. We believe this opens the way to new and more effective drug discovery."

An exclusive interview with Tim Allsopp, Chief Scientific Officer of Stem Cell Sciences, can be read at: http://www.ptemag.com/stemcells/

Searching for misprediction

A new bioinformatics tool is capable of identifying and correcting abnormal, incomplete and mispredicted protein annotations in public databases. The tool will help save the huge amount of time and effort that would otherwise be spent in further investigation of erroneously identified genes. "Recent studies have shown that a significant portion of eukaryotic genes are mispredicted at the transcript level," says Laszlo Patthy, who led the team that developed the approach.

The MisPred tool, developed by a team at the Institute of Enzymology of the Hungarian Academy of Sciences, uses five principals to identify suspect proteins: extracellular or transmembrane proteins must have appropriate secretory signals; a protein with infra-and extracellular parts must have a transmembrane segment; extracellular and nuclear domains must not occur in a single protein; the number of amino acid residues in closely related members of a globular domain family must fall into a relatively narrow range; and a protein must be encoded by exons located on a single chromosome. However, there are some exceptions to these rules. "Some secreted proteins may lack true secretory signal peptides as they are subject to leaderless protein secretion," says Patthy. "Similarly, it cannot be excluded at present that transchromosomal chimeras can be formed and may have normal physiological functions. Nevertheless, MisPred analyses of protein sequences of the Swiss-Prot database identified very few such exceptions, indicating that the rules of MisPred are generally valid."

http://www.biomedcentral.com/

News bites

Direct cell transformation

A team of researchers claims to have turned mouse exocrine cells directly into rare insulin-producing beta cells. The breakthrough has been hailed as a major step forward in the search for a treatment for Type II, and eventually Type I, diabetes. However, there is still a long way to go before a treatment can be tested in humans.

Read more at: http://www.ptemag.com/insulincells/

Nature does it best

The best place to seek novel compounds for pharmaceutical drugs is within natural systems, according to a discussion at a conference organized by the European Science Foundation. Such products would combine more effective treatment with reduced side-effects.

Read more at: http://www.ptemag.com/nature/

Precise protein production

A technique developed by UK researchers may lead to purer and more effective protein-based drugs. The technique allows drug developers to achieve 'chemical post-translational modification', which is vital for the manufacture of therapeutic proteins as it controls the way proteins are transported around the body.

http://www.isis-innovation.com/

Halt!

Following an imbalance of deaths, Cell Genesys has urgently halted the second of two Phase III clinical trials for its immunotherapy for prostrate cancer. The trial was designed to compare GVAX immunotherapy combined with Taxotere against Taxotere plus prednisone in patients with advanced-stage prostrate cancer. Of the114 deaths that occurred, 67 were in the GVAX plus Taxotere combination treatment arm. At this time, a cause for the deaths has not been identified.

http://www.cellgenesys.com/