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Freire JEC et al.
520 Rev Assoc Med Bras 2014; 60(6):520-524
Point of view
Bioethical conflicts of gene therapy: a brief critical review
Conflitos bioéticos da terapia gênica: uma breve opinião crítica
José E dnésio da Cruz Freire1*, Suelen Carneiro de Medeiros2, Antônio Viana Lopes Neto1, José Edvar Monteiro Júnior3,
Antônio Juscelino Sudário Sousa1, Antônio José Rocha1, Léa Maria Bezerra de Menezes4
1Department of Biochemistry and Molecular Biology, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
2Department of Clinical and Toxicology Analysis, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
3Biology Department, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
4Faculty of Pharmacy, Odontology and Nursing, Federal University of Ceará (UFC), Fortaleza, CE, Brazil
Summary
Study conducted at the Federal University
of Ceará, Fortaleza, CE
Article received: 3/26/2014
Accepted for publication: 6/3/2014
*Correspondence:
Address: Universidade Federal do Ceará,
Centro de Ciências, Departamento de
Biologia
Laboratório de Genética Molecular
Bloco 906, Campus do Pici
Av. Humberto Monte, s/n, PICI
Postal Code: 60455-970
Fortaleza – CE
Conflict of interest: none
Methods and techniques employed in gene therapy are reviewed in parallel with
pertinent ethical conflicts. Clinical interventions based on gene therapy techni-
ques preferentially use vectors for the transportation of therapeutic genes, howe-
ver little is known about the potential risks and damages to the patient. Thus, at-
tending carefully to the clinical complications arising as well as to security is
essential. Despite the scientific and technological advances, there are still many
uncertainties about the side effects of gene therapy. Moreover, there is a need, abo-
ve all, to understand the principles of bioethics as both science and ethics, in ac-
cordance with its socioecological responsibility, in order to prioritize the health
and welfare of man and nature, using properly natural resources and technology.
Therefore, it is hard to determine objective results and to which extent the inser-
tion of genes can affect the organism, as well as the ethical implications of it.
Keywords: gene transfer techniques, gene therapy, bioethics, ethics, clinical.
Introduction
The first scientific work involving gene transfer was des-
cribed in 1944 and involved two strains of Pneumococcus,
one pathogenic and the other nonpathogenic.1 However,
only in the 1950s the three-dimensional structure of DNA
was elucidated, allowing the emergence of what we now
know as genetic engineering. Since then, the possibility
of using the genes or gene fragments for different scien-
tific purposes emerged.2
About 10 years later, in 1963, the idea of anticipating
the in vitro culture of germ cells genetically engineered to
obtain direct control of these cells by selecting and inte-
grating specific genes in human chromosomes arises.3
Since then, numerous experimental designs in order to
establish safe methodologies to insert healthy genes into
defective cells were initiated.
However, the first successful in vitro gene correction
in mammalian cells occurred in 1977, using a viral vec-
tor as vehicle to transport the genetic material.4 The first
clinical trial of human gene therapy was performed in
1989 using a viral vector in five patients with metastatic
melanoma.5 This pioneering study in humans established
a number of important experimental designs for future
clinical interventions using gene transfer.
The method stimulated intense research in subse-
quent decades in an effort to optimize viral vectors for
the insertion of therapeutic DNA, leading to the possibi-
lity of clinical applications in humans.6-8 The choice of
viral vectors for the purpose occurred because these be-
ings possess the ability to recognize and infiltrate natu-
rally in the cell nucleus, and thus transfer the therapeu-
tic DNA into the host cell.9
Moreover, with the advent of human genome sequen-
cing and the development of new software tools for com-
paring genes, the diagnosis of almost all human diseases
related to genetic defects became possible. Thus, gene
therapy is currently the most efficient and promising cli-
nical tool available, being capable to predict with a high
level of accuracy if someone will develop a disease, as well
as to cure it.10
In general, gene therapy can be organized according
to its cellular target, being called somatic gene therapy
when the target is limited to somatic cells.11 This thera-