Adult skin cells al­ter de­bate over em­bry­onic stem cells

The Washington Times Weekly - - National - By Amy Fa­gan

Sci­en­tists from Ja­pan and the United States have changed hu­man skin cells into cells that look and be­have like em­bry­onic stem cells, a de­vel­op­ment that could be a turn­ing point in the con­tentious de­bate over hu­man em­bry­onic stem-cell re­search.

“It’s prob­a­bly the be­gin­ning of the end for that con­tro­versy,” said James Thompson, a stem-cell sci­en­tist at the Univer­sity of Wis­con­sin-Madi­son whose lab was used by the U.S. re­search team. “I do be­lieve that over time th­ese new cells will be used by more and more labs, and em­bry­onic stem cells will be grad­u­ally used by fewer and fewer labs.”

The idea is that th­ese new cells — pro­duced with­out harm­ing or us­ing any hu­man em­bryos — even­tu­ally could yield the same med­i­cal prom­ise as em­bry­onic stem cells.

The news had im­me­di­ate po­lit­i­cal im­pact, as op­po­nents of em­bry­onic stem-cell re­search said the need for such con­tro­ver­sial work is now gone.

“We have no re­al­is­tic need to de­stroy em­bryos,” said Sen. Sam Brown­back, Kansas Repub­li­can.

Oth­ers said that al­though the news is stun­ning, em­bry­onic stem­cell re­search should con­tinue.

“It’s a very im­por­tant sci­en­tific dis­cov­ery. It’s not one that ob­vi­ates the need for em­bry­onic stem­cell re­search,” said Sean Tip­ton, pres­i­dent of the Coali­tion for the Ad­vance­ment of Med­i­cal Re­search, a group that has led the charge for fed­eral fund­ing of stem-cell re­search.

The White House, mean­while, seemed vin­di­cated by the an­nounce­ment. Pres­i­dent Bush has twice ve­toed leg­is­la­tion that would have al­lowed fed­eral fund­ing to flow to even more em­bry­onic stem­cell re­search. In­stead, Mr. Bush has en­cour­aged other av­enues of re­search, in­clud­ing adult stem cells and al­ter­na­tive tech­niques such as the ones used in the stud­ies.

The Thompson team’s re­search was funded, in part, with fed­eral money from the Na­tional In­sti­tutes of Health.

A White House spokesman said Mr. Bush is “very pleased” with the dis­cov­er­ies.

“By avoid­ing tech­niques that de­stroy life, while vig­or­ously sup­port­ing al­ter­na­tive ap­proaches, Pres­i­dent Bush is en­cour­ag­ing sci­en­tific ad­vance­ment within eth­i­cal bound­aries,” the spokesman said.

Hu­man em­bry­onic stem cells are highly val­ued be­cause of their abil­ity to de­velop into es­sen­tially any body cell — a trait sci­en­tists think even­tu­ally could be used to treat a range of dis­eases. The catch is that hu­man em­bryos — which are some­times left over from in­vitro-fer­til­iza­tion clin­ics or pro­duced through a cloning tech­nique — must be de­stroyed in or­der to ex­tract their stem cells for the re­search. This has un­leashed a storm of con­tro­versy from the halls of Congress to the liv­ing rooms of Amer­ica, as peo­ple weigh the po­ten­tial med­i­cal prom­ise of stem cells against the value of hu­man em­bryos.

But the two sep­a­rate teams — one led by Dr. Shinya Ya­manaka of Ky­oto Univer­sity and the other led by Jun­y­ing Yu in Mr. Thompson’s lab — may have found a way to side­step that de­bate. Each team used viruses to in­ject a recipe of genes into hu­man skin cells and re­pro­gram the cells to act like em­bry­onic stem cells.

The Ya­manaka team, whose re­search is be­ing pub­lished in the jour­nal Cell, used four genes to re­pro­gram skin cells taken from a 36-year-old wo­man and a 69-yearold man. The Yu team, whose re­search is be­ing pub­lished in the jour­nal Science, also used four genes to re­pro­gram cells from fe­tal skin and from the fore­skin of a baby boy. The new cells are called in­duced pluripo­tent stem (IPS) cells.

The Ya­manaka team in June cre­ated mouse cells that were vir­tu­ally iden­ti­cal to stem cells, but this took the work a step fur­ther.

“Our study has opened an av­enue to gen­er­ate pa­tient- and dis­ease-spe­cific pluripo­tent stem cells,” the Ya­manaka team re­ported. The hu­man IPS cells are use­ful for un­der­stand­ing dis­ease mech­a­nisms, drug screen­ing and tox­i­col­ogy and “fur­ther stud­ies are es­sen­tial” to de­ter­mine whether they can re­place em­bry­onic stem cells in med­i­cal ap­pli­ca­tions, the re­searchers stated.

The new tech­nique car­ries with it some prob­lems, in­clud­ing the po­ten­tial for de­vel­op­ing can­cer.

Mr. Thompson, who first gained no­to­ri­ety for coax­ing stem cells from hu­man em­bryos in 1998, agreed more work is needed to en­sure safety. And he said it does- n’t mean the end of em­bry­onic stem-cell re­search. But he said “the world has changed” be­cause of it.

The news evoked praise from sci­en­tists, ethi­cists and law­mak­ers alike.

“This is ex­tremely sig­nif­i­cant re­search be­cause what they’ve done is pro­duce em­bry­onic-type stem cells with­out any of the eth­i­cal bag­gage,” said David Pren­tice, se­nior fel­low for life sci­ences at Fam­ily Re­search Coun­cil. “They don’t cre­ate or de­stroy any em­bryos; they don’t have to do any cloning; they don’t need any eggs.”

Some well-known sci­en­tists al­ready have be­gun to shift to­ward this new tech­nique.

Dr. Ian Wil­mut, the Bri­tish sci­en­tist who cloned Dolly the sheep, re­cently told the Tele­graph that he will aban­don the cloning method that pro­duced the an­i­mal in fa­vor of Dr. Ya­manaka’s method of pro­duc­ing cells.

But oth­ers warned that em­bry­onic stem-cell re­search is still just as im­por­tant.

“Th­ese sci­en­tists have per­formed truly ground­break­ing and his­toric ac­com­plish­ments. Still, our top re­searchers rec­og­nize that this new de­vel­op­ment does not mean that we should dis­con­tinue study­ing em­bry­onic stem cells,” said Sen. Tom Harkin, Iowa Demo­crat and a stem-cell re­search pro­po­nent.

Cloning em­bryos to pro­duce stem cells is still too pow­er­ful a tool to aban­don, agreed Ru­dolf Jaenisch, a stem-cell sci­en­tist at the White­head In­sti­tute.

Mr. Tip­ton said al­though the re­cent dis­cov­er­ies in­tro­duce more “com­pe­ti­tion” into the field, “we need to let sci­en­tists tell us what the best source is” — an out­come that only time will tell.

This ar­ti­cle is based in part on wire ser­vice re­ports.

As­so­ci­ated Press

Mouse cells that were nearly iden­ti­cal to stem cells were cre­ated in June by a re­search team led by Dr. Shinya Ya­manaka of Ky­oto Univer­sity. New re­search has taken that work a step fur­ther.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.