GENE THERAPY

[seminar class]

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INTRODUCTION
 It is a technique for correcting defective genes
 There are four approaches:
 A normal gene inserted to compensate for a nonfunctional gene.
 An abnormal gene traded for a normal gene
 An abnormal gene repaired through selective reverse mutation
 Change the regulation of gene pairs.
what is gene ?
 Gene is the biological unit of heredity
 A gene is a part of DNA molecule
 Genes determine obvious traits, such as hairs and eye colour
 Gene carry instructions that allow to cells to produce
 specific proteins, such as enzymes.
HISTORY OF GENE THERAPY
• 1972- In 1972 Friedmann and Roblin authored a paper in Science Ref. Friedmann 1972 Gene|"Gene therapy for human genetic disease?".
• 2002- Sickle cell disease is successfully treated in mice. See ''Murine Gene Therapy Corrects Symptoms of Sickle Cell Disease'' from March 18, 2002, issue of The Scientist.
• 2003- In 2003 a University of California research team inserted genes into the brain using liposomes coated in a polymer called polyethylene glycol (PEG). The transfer of genes into the brain is a significant achievement because viral vectors are too big to get across the blood-brain barrier.
• 2006- Scientists at the National Institutes of Health (Bethesda) have successfully treated metastatic melanoma in two patients using killer T cells genetically retargeted to attack the cancer cells. This study constitutes the first demonstration that gene therapy can be effective in treating cancer.
• 2009- In September of 2009, the journal Nature reported that researchers at the University of Washington and University of Florida were able to give trichromatic vision to squirrel monkeys using gene therapy, a hopeful precursor to a treatment for color blindness in humans.
Types of gene therapy
1. Germ line gene therapy: -Involve the genetic modification of germ cells.
2. SOMATIC GENE THERAPYL:-This involve the genetic modification of somatic cell’.
How does gene therapy work ?
 In most gene therapy studies, normal gene is inserted into the genome to replace an “abnormal diseases causing gene.
 This could be in vivo or ex vivo
 A carrier molecule called a vector must be used to delivered the therapeutic gene to the patient target cells.
 The most common vector is a virus that has been genetically altered to carry normal human DNA.