Stem cell specialist apologizes and resigns

TOKYO -- Hwang Woo Suk, one of the world's leading stem cell specialists whose South Korean team created the first cloned human embryo and the first cloned dog, apologized yesterday for ethical breaches at his lab and said he would resign from all his official posts.

Under mounting pressure from the international scientific community, Hwang, 52, admitted his team had used ova samples extracted from two of his junior scientists during research that led to the team's historic cloning of a human embryo in 2003.

Such practices are considered highly unethical in international scientific circles.

Choking back tears, Hwang said he had not known about the women's donations until the magazine Nature began investigating the source of his team's ova specimens early last year.

Even after discovering the truth, he denied the allegations out of fear that his project would be jeopardized, he said.

The women had asked that their privacy be maintained, he said.

''Being too focused on scientific development, I may not have seen all the ethical issues," Hwang said.

A national hero in South Korea, Hwang has recently been dogged by international allegations of ethical impropriety that have threatened to severely set back his work.

Last month, Hwang and several leading scientists launched the Seoul-based World Stem Cell Hub, a project aimed at seeking treatments for diseases that remain incurable.

But earlier this month, University of Pittsburgh researcher Gerald Schatten said he was pulling out of his association with Hwang, citing concerns about the way the group had obtained human eggs.

The difficulty in procuring the eggs is typically one of the most vexing obstacles to large-scale stem cell research.