Stem Cells

Abstract

1. The object of this Paper is to provide an independent assessment of the Donaldson Committee's Recommendations in light of the most recent advances in stem cell research.

2. Stem cells should be defined by their ability to renew themselves and diversify into other cell types.

3. There are several readily accessible sources of stem cells. Strict criteria apply to the use of these sources in medical research.

4. Stem cells have wide potential application in medicine. "Adult" stem cells have already been used in the world's first recorded case of successful gene therapy "surgery".

5. The views expressed by the Donaldson Committee's on the limitations of "adult" stem cells are now defunct.

6. Unlike "embryonic" stem cells, "adult" stem cells have already been used extensively in the successful treatment of a range of degenerative diseases and conditions and have outstanding development potential.

7. The objections to the use of "adult" stem cells advanced by the National Institutes of Health in the U.S. have been overcome, according to the most up-to-date research.

8. "Adult" stem cells have now surpassed all other sources of stem cells in terms of widespread clinical application, safety, availability and potential.

Introduction

Following the publication of stem cell research: Medical Progress with Responsibility, the long-awaited Report of the Chief Medical Officer's Expert Advisory Group on Therapeutic Cloning (August 2000), a fierce debate has ensued over the Government's decision to "accept the Report's recommendations in full."

Focusing on the first Recommendation made by the Advisory Group (otherwise known as the Donaldson Committee) that:

"Research using human embryos (whether created by in vitro fertilization or cell nuclear replacement) to increase understanding about human disease and disorders and their cell based treatments should be permitted, subject to the controls in the Human Fertilization and Embryology Act 1990."

serious ethical objections have been raised to the proposal to deliberately create and clone human embryos for the purpose of stem cell extraction, particularly in view of what opponents claim is a clearly defined and ethical alternative in adult stem cells.

However, the Donaldson Committee's Report clearly states that the ethical objections to the cloning of human embryos for this purpose are "outweighed by the potential benefits" of using embryonic stem cells to advance research into the treatment of degenerative diseases.

Submitted to the Department of Health as long ago as January 2000, the Report's recommendations are based on the most up-to-date scientific evidence available to the Donaldson Committee between January and December 1999, no less than nine months ago. And such is the pace of advances in the field of stem cell research, many experts, including scientists and medical doctors, have since challenged the basis for the Report's findings.

The object of this Briefing Paper, therefore, is to provide independent and informed analysis of the most up-to-date, cutting-edge stem cell research, in order to better inform those Members of the United Kingdom Parliament who intend to vote on whether to accept the Recommendations made by the Donaldson Committee.

Background

The Chief Medical Officer's Advisory Group defined stem cells as "unspecialized cells which have not yet differentiated into any specific type of tissue."3 This definition is consistent with the one applied by the National Institutes of Health, the body appointed by President Clinton to consider the value of research using Human Pluripotent Stem Cells (HPSCs).

However, the limitations of this definition were made clear by David A. Prentice, Professor of Medical and Molecular Genetics at Indiana State University, in his testimony before the American Congress in February 2000. Dr Prentice defined stem cells as:

"...cells that can proliferate with almost unlimited potential, maintaining a pool of growing and dividing cells, with the added ability that some of the daughter cells can differentiate into specific cell types."4

This definition accords greater significance to the unique capacity of stem cells to constantly renew themselves, whilst maintaining an ability to adapt to the specific cell types needed by the human body. It is these unique properties that distinguish stem cells from other cell-types in terms of clinical application and that are central to the debate over the use of embryonic versus adult stem cells.

The human body is a stem cell "gold mine", providing an almost unlimited source of stem cells. However, the problem lies not in locating these cells, but in isolating them from their source.

With this in mind, scientists have isolated several key "ready-made" sources of stem cells, often referred to as "reservoirs". The following sources fall within this category:

Blastocysts - embryos after six days of growth.

Early embryos created by human cloning.

Fetal Tissue.

Adult or child tissue.

Adult or child cells that can be grown into stem cells.

To date, only stem cells taken from adults or children (known generically as "adult stem cells") have been used extensively and effectively in the treatment of degenerative diseases.

There are over 4,000 registered diseases specifically linked to genetic abnormalities, as well as a host of others which are thought to have a genetic component. Yet, although stem cells are unlikely to provide fast-track miracle cures for these conditions - and are even less likely to lead to a cure for all known human disease, as certain commentators have speculated - they are unique in their potential application to a large number of these diseases. As tiny factories that have an ability to "re-stock" themselves when required and develop a wide range of specialties, stem cells meet the technical specifications for use in gene therapy..

Indeed, in many pioneering research projects, completed since the turn of the Millennium, scientists have demonstrated that stem cells can be used to replenish or rejuvenate damaged