primegen-logo-205px.gifLast week, the Irvine, Calif., startup PrimeGen Biotech made a startling claim: It had successfully transformed adult skin, kidney and retina cells into stem cells, without using viral gene therapy that could trigger cancer. That would represent a significant advance over the discovery last year (see our coverage) that inserting just four genes into ordinary cells could reawaken their ability to transform themselves into any type of tissue, potentially opening the door to regenerative medicine that doesn’t rely on stem cells derived from five-day-old embryos.

But there’s no shortage of reasons to treat PrimeGen’s claims with skepticism, starting with the fact that it chose to announce them at last week’s Stem Cell Summit, an investment conference in New York whose Web site already seems to be defunct. Add in the facts that PrimeGen has been making similar claims for more than two years but hasn’t ever published its findings in a scientific journal, that it only seems to present actual data at obscure overseas meetings — one organized by the Pontifical Academy for Life and the World Federation of Catholic Medical Associations, for instance, and another arranged by Serono Symposia International, a producer of continuing medical educational events — and that it appeared inordinately tickled when a pro-life U.S. Senator praised its work as “the greatest thing on the horizon” in a 2006 congressional hearing, and you have an awfully good basis for suspicion.

PrimeGen also stands out as a very odd duck in the world of stem-cell startups. The company has largely been bankrolled by two tech-industry entrepreneurs, Kingston Technology co-founder John Tu and AST Research co-founder Thomas C.K. Yuen, neither of whom have any background in biology or medicine so far as I can tell — or even a history of supporting such work. Yuen, in fact, serves as PrimeGen’s chairman and CEO, another discordant note. The company’s Web site is an amateurish mess rife with scientific vaguery of the highest order, meaningless puffery — did you know that PrimeGen is “the global leader” in stem-cell research and regenerative medicine? Me neither — and executive bios that tout routine biomedical accomplishments such as “being a Principle[sic] Investigator of NIH grants” as if they were the Nobel Prize.

That’s all shaky enough, but none of it gave much pause to mainstream publications such as the U.K. magazine New Scientist and the Philadelphia Inquirer, which played up the company’s unsubstantiated claims in recent articles (see here and here). Only the Inquirer offers a few reasons to question PrimeGen’s alleged achievement — in particular, pointing out that research now suggests it takes about two weeks to turn normal cells into what are technically callled “induced pluripotent stem cells,” whereas PrimeGen claims to do it in five to seven days.

The New Scientist piece, which goes into the most detail about PrimeGen’s technique, says the company used stretches of DNA that “code” for the same four genes used in one of last November’s gene-therapy experiments plus a fifth gene called Nanog. The company’s scientists supposedly attached the DNA to carbon nanoparticles that it mixed with the adult cells to reprogram them into iPS cells. Using the proteins coded by the genes allegedly had the same effect.

All this is certainly plausible — but so were other stem-cell “breakthroughs” that never panned out, most notably fabricated research touted by in 2005 by South Korean researcher Hwang Woo Suk, who claimed to have produced embryonic stem cells from adult tissue via cloning. Of course, it’s impossible to rule out the possibility that PrimeGen can indeed do exactly what it says here, but the signs aren’t auspicious. PrimeGen says it has submitted its latest results to a stem-cell meeting in Philadelphia this summer, and its science had better match or exceed its hype if it wants to be anything but a colossal vanity project.