Gene Therapy – alsa.org
Posted: January 3, 2017 at 10:40 am
In amyotrophic lateral sclerosis (ALS), gene therapy may help if it can deliver a beneficial protein to salvage dying nerve cells. Gene therapy can be simply a means to boost on site production of a helpful factor, at places where nerve cells are in trouble. Researchers can disarm many types of viruses, and put in the genetic instructions to make therapeutic protein. The redesigned viruses are called vectors. They are simply carriers for therapeutic genes. Knowledge of the SOD1 mutations linked to some forms of ALS has produced a vast body of evidence, pointing to a general strategy for the disease that might be successfully implemented through gene therapy.
Gene therapy is the use of genetic instructions to produce a protein to treat a disorder or deficiency. It can aid in a disease even if the therapy is not directly targeting a gene defect that causes the disease. In amyotrophic lateral sclerosis (ALS), gene therapy may help if it can deliver a beneficial protein, to salvage dying nerve cells. The gene therapy simply is a means to boost on site production of a trophic (growth enhancing) factor, at places where nerve cells are in trouble.
Genes are the molecules in all cells of our bodies that carry the instructions to make all of the materials that comprise the body. In the 1950s, scientists determined that genes code precisely for proteins, with a sequence that specifies the order of the building blocks of proteins, the amino acids. Each gene corresponds to a protein. Each base in a gene codes for an amino acid. The order of bases in a gene produces the ordered chain of amino acids that produce a working protein.
At the turn of the current century, scientists determined, in rough draft form, the sequence of all of the human genes. By this time, they also knew how to create a gene construct, and move that construct into cells, to get the cells to make the corresponding protein.
In some diseases, researchers already know that a defective gene is not able to work. They have the potential means to cure the disease, by replacing the defective gene with a correct, working copy. In ALS, only a few percent of patients have a known gene defect. For the rest, it may be one undiscovered gene that is the problem, or it may be several. But gene therapy can still be designed to aid patients with ALS by providing supportive proteins for nerve cells.
Genes normally reside in the nucleus, the core of a cell, separated from the surrounding materials by a membrane. The chromosomes are the structures within the cell nucleus that contain the DNA that comprises the genes. It is very challenging to get a gene made in the lab to cross both the outer envelope of a cell, and the nuclear membrane as well, to reach the chromosomes.
Scientists studying viruses have discovered natures own solution to the problem of moving genes. Viruses are essentially genes that have evolved to hijack cells, instead of forming cells for themselves. So viruses have strategies to enter cells and take over the protein production process, to produce instead, the virus. Researchers have figured out how to use viruses as Trojan horses, to bring in genes that can then carry out genetic repairs, replacing defective DNA.
For many viruses, researchers can disarm the genes responsible for the damaging properties and put in, instead, genetic instructions to make therapeutic proteins. These viruses, redesigned by researchers, are called vectors. They are simply a means to smuggle in therapeutic genes.
Investigators must demonstrate that the viral vector is not going to revert back to an infectious form, or cause any side effects.
Genes normally are read out only when a protein is needed, and operate under feedback control. If adequate amounts of protein are already there, then the gene is turned off. Scientists have to be able to devise the proper switch elements to accompany a therapeutic gene, to make sure that a gene is expressed in proper amounts, and only in an intended target tissue.
To gauge adequate delivery of the vector, and sufficient levels of gene expression, researchers have to have animal models that reflect the key manifestations of a human disease. Despite preclinical work with animals, it is not always possible to extrapolate to patients.
A patients immune system may mount an attack on viral vectors (after all, that is what the immune system is primed to do), or on the newly introduced therapeutic gene product.
In ALS, a few percent of patients have a known defect in a gene. This genetic mistake, in the gene coding for the SOD1 protein, produces disease no different from any other form of ALS, inherited or not. Gene therapy might be designed for a particular SOD1 defect, but that therapy may or may not work for other ALS patients.
What is encouraging is that the knowledge of the SOD1 mutations has produced a vast body of evidence for what does go wrong in other cases of ALS. And that evidence is pointing to a general strategy that might be successfully implemented through gene therapy.
ALS research has produced the notion that the neighborhood surrounding the motor neurons can be nurturing or detrimental to these crucial cells affected in ALS. Even if a neuron carries a mutated SOD1 gene, that nerve cell can survive if neighboring support cells, the glia, have the normal gene (see section on Cell Targets).
Glial cells surround neurons. Some glial functions produce the hallmarks of damage in the nervous system, either inflammation or scarring. Other glial actions are protective, for instance, sweeping away excess excitatory signal molecules before they can do damage. Gene therapy in ALS may be able to target the glial cells as well as neurons, to produce positive effects.
Studies in animal models of ALS show increased survival after treatment with trophic factors (see section on trophic factors), small proteins that support the growth and metabolic activities of nerve cells, most recently with IGF-1 and also after vascular endothelial growth factor (VEGF). However, clinical trials of trophic factors in ALS patients have been disappointing. The challenge of delivering these proteins to the site of damage is likely the underlying cause of the failures in the clinic.
Gene therapy may be the way to provide a steady supply of trophic factors to neurons damaged in ALS, directly at the place where the damage exists. The ALS Association is supporting various avenues of research that seek to implement gene therapies to deliver trophic factors, and is encouraging entry into clinical trials as quickly as possible.
View original post here:
Gene Therapy - alsa.org
- Gene Therapy Could Prevent Blindness [Last Updated On: June 10th, 2010] [Originally Added On: June 10th, 2010]
- Gene Brodland Sits with Cambridge Who's Who in a Revealing Interview [Last Updated On: June 16th, 2010] [Originally Added On: June 16th, 2010]
- Researchers Make Colon Cancer Breakthrough [Last Updated On: July 20th, 2010] [Originally Added On: July 20th, 2010]
- Pro abortion- Antiabortion myth8 - Fly to India for safe abortion! [Last Updated On: October 16th, 2010] [Originally Added On: October 16th, 2010]
- New Fertility Test / Whooping Cough Alert / Gene Therapy for Depression [Last Updated On: October 21st, 2010] [Originally Added On: October 21st, 2010]
- Alzheimer's Breakthrough? [Last Updated On: October 23rd, 2010] [Originally Added On: October 23rd, 2010]
- Audio Genetics Lab - Native Flute - MP3Tera Forums [Last Updated On: December 8th, 2010] [Originally Added On: December 8th, 2010]
- Gene Therapy - Cortical Studios [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- There Shall Be Physicians for the Spirit: USC Institute for Genetic Medicine Art Gallery [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- IRRI: Rice genetic diversity and discovery [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Research Symposium: Mork Depart - 2006 - Video 1 [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Mendelian Genetics [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Ayurveda [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Drs. Kaspar and MacKenzie discuss the promise and path forward for SMA Gene Therapy [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- 3. Genetic Engineering [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Prof. Martinez Cruzado Lecture Part 3 "Amerindian Gene Study In Puerto Rico" [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Gene Therapy Research Makes Nationwide Children's Worthy of Wellstone Center [Last Updated On: May 8th, 2011] [Originally Added On: May 8th, 2011]
- Gene Therapy Example [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Sweet Tooth Gene [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- OHSU's video of new gene therapy method developed at the Oregon National Primate Research Center [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Gregor Mendel's Punnett Squares [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Ethical Concerns With Genetic Engineering [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Dr. Laura Niklason on the importance of her AFAR grants for telomerase gene therapy research [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- What is the future of genetic medicine? [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Prof. Martinez Cruzado Lecture Part 2 "Amerindian Gene Study In Puerto Rico" [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Jewish DNA - Genetic Research and The Origins of the Jewish People [Last Updated On: May 9th, 2011] [Originally Added On: May 9th, 2011]
- Future of genetic engineering - by Futurist Dr Patrick Dixon. Genetic mutations and genetic disorders. Gene science by conference keynote speaker [Last Updated On: May 11th, 2011] [Originally Added On: May 11th, 2011]
- annstewart82's Genetic Medicine and God [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Genetic research could unlock breeding seasons in sheep [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Genetics 101 Part 1: What are genes? [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Molecular and Cellular Foundations of Medicine, 1 of 2 [Last Updated On: May 13th, 2011] [Originally Added On: May 13th, 2011]
- Dan Arking of Johns Hopkins Medicine [Last Updated On: May 17th, 2011] [Originally Added On: May 17th, 2011]
- Genetics : How Is Gene Therapy Done? [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Gene Therapy Shows Promise for Blindness [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Tomato suicide gene therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Cancer Alternative Treatment - Gene Therapy for Cancer a Report from Channel 4 News [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Muscular Dystrophy Gene Therapy: ScienCentral News Video [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Sickle Cell Anemia -- Hope from Gene Therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Challenges of gene therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Pain Gene Therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Gene therapy success 'reverses' blindness [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- DNA Gene Therapy [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- The Neural Circuitry of Perception [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Resetting Metabolism- Nuclear Receptors and AMPK: A Lecture by Ronald Evans, PhD [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Islands at Risk (Part 2) - Genetic Engineering in Hawai'i [Last Updated On: May 19th, 2011] [Originally Added On: May 19th, 2011]
- Gene Therapy journal videocast from ASGCT 2011 Xiao Xiao on gene therapy for muscular dystrophy [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- HYBRID HUMANS-Hair Follicle Gene Therapy [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Genetics 101 Part 4: What is phenotype? [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Lloyd Pye - Ancient Genetic Engineering [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Study Designs: Genetic Association Studies [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Gene Therapy for Genetic Disease: The Long and Winding Road [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Introduction to Population Genetics [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Islands at Risk (Part 1) - Genetic Engineering in Hawai'i [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Genetics Based Research on Treatment-Resistant Epilepsy [Last Updated On: May 20th, 2011] [Originally Added On: May 20th, 2011]
- Science in Action: Gene Therapy for Color Blindness [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- Gregg Semenza of Johns Hopkins Medicine on HIF 1 [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- The Sleepiness Gene [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- Blind Gene Therapy [Last Updated On: May 21st, 2011] [Originally Added On: May 21st, 2011]
- Richard Dawkins and Dr Yan on genetic ancestry (extended version) - Bang Goes the Theory - BBC One [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Joshua Mendell of Johns Hopkins Medicine [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Genetic/Genomic Faculty Champion Initiative (PM session) [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- euronews science - Epigenetics [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- The Genetic Age, Panel 1 [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Biobanking and Bioethics: When Genetics Research Hits the Courts [Last Updated On: May 22nd, 2011] [Originally Added On: May 22nd, 2011]
- Gene Therapy journal videocast from ASGCT 2011 Darren Wolfe on gene therapy for pain.m4v [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Genetics 101 Part 3: Where do your genes come from? [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- ASHG 2010 Mtg.: "Complex Disease Genetics Research in Populations" (Dr. Carlos Bustamente) [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Public Talk - Prof Leonard Seymour, Oxford [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- A New Era in Medicine: Genetics [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Genetic Engineering Animation [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Linda Brzustowicz - Genetic Causes of Schizophrenia [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Hadassah Gene Therapy Center [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Gene Therapy journal videocast from ASGCT 2011 Robin Ali on gene therapy for retinal disease [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- UF cardiologists study gene-modified stem cells to help Dobermans with common heart condition [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Akhilesh Pandey of Johns Hopkins Medicine [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- China's Cancer Drug - China [Last Updated On: May 23rd, 2011] [Originally Added On: May 23rd, 2011]
- Genetic Therapy Restored Boy's Sight [Last Updated On: May 24th, 2011] [Originally Added On: May 24th, 2011]
- Molecular and Cellular Foundations of Medicine Class, 2 of 2 [Last Updated On: May 24th, 2011] [Originally Added On: May 24th, 2011]
- Talking Research - Professor George Ebers - Vitamin D and genetics in MS [Last Updated On: May 24th, 2011] [Originally Added On: May 24th, 2011]
- Designing Humanity - Genetic Engineering [Last Updated On: May 30th, 2011] [Originally Added On: May 30th, 2011]