US President George W. Bush has delivered on his pledge to veto the Stem Cell Research Enhancement Act of 2007.

Confirming the veto earlier this week, President Bush also announced an executive order ensuring federal funding would be available for research using pluripotent stem cells generated without recourse to human embryos. However, supporters of the stem cell research bill dismissed the order as a distraction that provided no new federal funding for stem cell research and added nothing to activities already permitted under existing restrictions.

Congressional backers of the Stem Cell Research Enhancement Act, which was approved with bipartisan majorities in the Senate and the House of Representatives, are now examining their options for pushing through legislation that would ease the current tight limitations on federal funding for stem cell research using discarded human embryos. An immediate but interim possibility is amendments to a federal spending bill that would move forward by nearly six years the cut-off point for stem cell lines eligible for government research funding.

Second rejection

This is the second time President Bush has thrown out legislation aimed at improving conditions for stem cell research using human embryos. The Stem Cell Research and Enhancement Act of 2005 was vetoed by the president on ethical grounds in July 2006. At a briefing last Wednesday, Bush said the revived bill would “compel American taxpayers – for the first time in our history – to support the deliberate destruction of human embryos. I made it clear to Congress and the American people that I will not allow our nation to cross this moral line.”

According to the president, his administration has made more than $130 million available for research with stem cells “derived from embryos that had already been destroyed” since August 2001, when Bush issued an executive order restricting government funding to research using the small pool of embryonic stem cell lines then available for study. Another $3 billion has been provided for research on all forms of stem cells, including those from adult or other non-embryonic sources.

The president also claimed his new executive order would “encourage scientists to expand the frontiers of stem cell research”. The order on Expanding Approved Stem Cell Lines in Ethically Responsible Ways directs the Secretary of Health and Human Services to “conduct and support research on the isolation, derivation, production and testing of stem cells that are capable of producing all or almost all of the cell types of the developing body … but are derived without creating a human embryo for research purposes or destroying, discarding or subjecting to harm a human embryo or foetus”.

It also renames the Human Embryonic Stem Cell Registry to the Human Pluripotent Stem Cell Registry and adds to the registry human pluripotent stem cell lines (those with potential to develop into any of the three major tissue types) that “clearly meet” the conditions detailed above.

On the boil

In the meantime, Democrats and other congressional supporters the Stem Cell Research Enhancement Act of 2007 are determined to keep the legislation on the boil. While at present neither chamber of Congress has the two-thirds majority needed to override the presidential veto, the bill’s sponsors insist they are in for the long term and that stem cell research will be an election issue in 2008.

In the shorter term, Tom Harkin, Democrat Senator for Iowa state, has inserted a new provision into an appropriations bill for the US Departments of Labor, Education and Health and Human Services that would extend federal funding to embryonic stem cell lines created before 15 June 2007.

The results of a survey conducted by researchers from Johns Hopkins and Duke University have bolstered accusations that President Bush is out of step with the bulk of the US public in his intractable opposition to the use of embryonic stem cells. The findings are due to be published in the 6 July issue of the journal Science.

Out of 1,020 couples with frozen embryos in storage from fertility treatments who responded to the survey, 49% said they were somewhat or very likely to donate unused embryos to medical research while 60% gave the same answer for stem cell research specifically. The infertility patients were far more likely to donate their embryos to scientists for stem cell research than to other couples for adoption (22%).