"Long before it's in the papers"
November 14, 2007

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Monkey embryos reported cloned

Nov. 14, 2007
Courtesy Nature
and World Science staff

Sci­en­tists are re­port­ing the first suc­cess­ful use of cloning to pro­duce mon­key em­bryos, which they then used to pro­duce “mas­ter” or stem cells that po­ten­tially could serve to treat dis­eases.

Al­though sev­er­al spe­cies have been cloned, sci­en­tists haven’t pre­vi­ously done it with pri­ma­tes. In the re­search jour­nal Na­ture this week, the re­search­ers re­ported us­ing a tech­nique called so­mat­ic cell nu­clear trans­fer to “re­pro­gram” cells from adult rhe­sus mon­keys in­to em­bry­on­ic stem cells.

The tech­nique in­volved in­ject­ing the nu­cle­us from an adult mon­key cell in­to an egg cell with its own nu­cle­us re­moved. The re­search­ers then in­duced an early-stage em­bry­o called a blas­to­cyst, and teased out and cul­ti­vat­ed stem cells.

Cre­at­ing em­bry­on­ic stem cells through this pro­cess has only been done in mice. It is thought that in hu­mans, such em­bry­on­ic stem cells could be used to treat a va­ri­e­ty of dis­eases with­out im­mune re­jec­tion, as they could be tai­lored to in­di­vid­ual pa­tients.

The sci­en­tists, led by Shoukhrat Mi­tal­ipov of Or­e­gon Health & Sci­ence Un­ivers­ity, said they gen­er­at­ed two em­bry­on­ic stem cell lines from 304 egg cells tak­en from 14 rhe­sus mon­keys. Their suc­cess with pri­ma­tes sug­gests this ap­proach might work in hu­mans for the pur­pose of gen­er­at­ing em­bry­on­ic stem cells de­rived from in­di­vid­ual pa­tients, they said.

In a re­lat­ed com­men­tary in the jour­nal, Ian Wilmut and Jane Tay­lor of the Un­ivers­ity of Ed­in­burgh, U.K., wrote that such cells have po­ten­tial not only for treat­ing dis­eases but for un­der­stand­ing the ge­net­ics of dis­ease. 

“In our haste to use patient-specific cells in ther­a­py,” they wrote, “we tend to over­look that they have great val­ue for bas­ic re­search and drug dis­cov­ery. For ex­am­ple, such cells could pro­vide new ways to study in­her­it­ed dis­eases.” An in­de­pend­ent team led by Da­vid Cram of Mo­nash Un­ivers­ity in Aus­tral­ia car­ried out an ex­pe­ri­men­tal val­ida­t­ion of the re­search, ac­cord­ing to the jour­nal.

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Scientists are reporting the first successful use of cloning to produce monkey embryos, which they then used to produce “master” or stem cells that potentially could serve to treat diseases. Although several species have been cloned, scientists haven’t previously done it with primates. In this week’s issue of the research journal Nature, the researchers reported using a technique called somatic cell nuclear transfer to “reprogram” cells from adult rhesus monkeys into embryonic stem cells. The technique involved injecting the nucleus from an adult monkey cell into an egg cell with its own nucleus removed. The researchers then induced an early-stage embryo called a blastocyst, and teased out and cultivated stem cells. Creating embryonic stem cells through this process has only been done in mice. It is thought that in humans, such embryonic stem cells could be used to treat a variety of diseases without immune rejection, as they could be tailored to individual patients. The scientists, led by Shoukhrat Mitalipov of Oregon Health & Science University, said they generated two embryonic stem cell lines from 304 egg cells taken from 14 rhesus monkeys. Their success with primates suggests this approach might work in humans for the purpose of generating embryonic stem cells derived from individual patients, they said. In a related commentary in the journal, Ian Wilmut and Jane Taylor of the University of Edinburgh, U.K., discussed the potential of such cells not only for treating diseases but to understand the genetics of disease. “In our haste to use patient-specific cells in therapy,” they wrote, “we tend to overlook that they have great value for basic research and drug discovery. For example, such cells could provide new ways to study inherited diseases.” An independent team led by David Cram of Monash University in Australia carried out an experimental validation of the research, according to the journal.