Brazil edges toward therapeutic cloning

The Brazilian government is to provide about US$2 million to support research involving the use of tissues to replace damaged tissues and organs. Such tissue could be taken from cloned human embryos, a process referred to as ‘therapeutic cloning’.

The money will be used primarily to strengthen the links between medical research centres already active in this field of research, which is expected to lead to improved treatment for various degenerative diseases, such as Alzheimer’s disease and muscular dystrophy.

In addition, according to Wim Degrave, a geneticist at the Oswaldo Cruz Foundation (Fiocruz) in Rio de Janeiro, it can help the recovery of cells and tissues damaged by cancer, heart attacks, car accidents, and burns.

The new fund is part of the Millennium Science Initiative, which has been launched jointly by the Brazilian government and the World Bank, and aims to develop networks of prominent research groups in important areas of science.

“The goal of this project, which links together 13 scientific centres throughout Brazil, is to support the country’s capability in a new medical area”, says the minister of Science and Technology, Ronaldo Sardenberg.

Speaking at a seminar organised by the Federal Senate in the national capital, Brasilia, earlier this month, Sardenberg announced his support for human therapeutic cloning, stressing its potential contribution to improving public health.

The seminar was intended to help the Brazilian Congress analyse various proposals that are being made to change the law on human cloning. At present, this is regulated indirectly through a law covering research on genetically modified organisms.

In addition, the National Technical Commission in Biosafety (CTNBio) has established guidelines for its employees on how to deal with human cloning.

Under current legislation, genetic manipulation of both germ cells and totipotent cells — undifferentiated cells that can develop into the specific tissues and organs that make up the human body — is forbidden. But there is no constraint on such work if it does not involve genetic modification.

Government officials now think that, with recent biomedical advances in regenerative medicine, the law should be changed. “The law is too restrictive in terms of experiments involving cellular nuclear transfer”, says Ésper Carvalheiro, president of CTNBio, and a neuroscientist at the Federal University of São Paulo (UNIFESP).

Nine separate proposals for a new law on human cloning have been submitted to the Brazilian Congress. The main bill was proposed in 1999 by centre-left Senator Sebastião Rocha.

This would ban all forms of human cloning, whether for therapeutic or reproductive purposes. Also, anyone involved in such an experiment, including scientists and representatives of funding agencies, would be prosecuted.

Rocha now says that he accepts that there are significant differences between therapeutic and reproductive human cloning, and is re-writing the proposed law. “We are working to allow human therapeutic cloning and to prohibit human reproductive cloning”, says Rocha.

The Brazilian government has chosen to support amendments to Rocha’s bill, rather than present its own legislative proposals. To achieve this, it has set up a working group to analyse the text, and is due to submit its report to Rocha shortly.

Several research groups in Brazil are already working on totipotent cells. Those at an advanced stage who are ready to use undifferentiated stem cells in humans are dealing with non-genetic diseases, such as heart diseases caused by Chagas’ disease and heart attacks

“These groups are studying so-called ‘self-graft’,” explains Mayana Zatz, a geneticist of University of São Paulo (USP), referring to the way that researchers take cells from a patient (for example from the spinal cord), and then reprogramme the cells and re-implant them into the patient.

In contrast for genetic diseases, points out Zatz, cells need to be obtained from other individuals who do not have the mutation carrying the disease. Suitable cells can be taken from the spinal cord, umbilical cord, and discarded embryos, but the use of the latter in research is causing controversy in Brazil, as elsewhere.

© SciDev.Net 2002