yulius hermanto
Human Gene Therapy: A New Hope
Disease is part of human life, we may avoid certain kind of diseases such as infectious, trauma or injury, lifestyle related diseases; but how about the genetic diseases. The genetic diseases often related with mutant genes; the mutant genes lead to production of malfunction protein thus disrupt cell function.
Most of the genetic disease occurs through embryonic development, except cancer. Eventhough, the current knowledge of inheritance of gene can predict the occurance of the disease in the offsprings, but it just percentage or chance of having the disease. Early diagnostic of certain genetic disease during embryonic period may leads to abortion in certain countries.
People who suffer the genetic disease often frustated since they will experience their abnormality for their entire life, without a chance to get away from it. The cost of the treatment is quite expensive and often supportive.
Eventhough gene therapy is still at an early stage of development, a large amount of research has already been conducted. Many of them are aimed at alleviating inherited human diseases.
Illustration of Genetic Disease
Thalassemia, is a disease that caused by abnormal protein of hemoglobin that decreases the lifespan of red blood cell. The patient with thalassemia needs monthly transfusion for entire life. And may suffering the complication of transfusion especially high iron deposit in tissues.
Duschenne Muscular Dystrophy is a disease that caused by lack of specific protein in muscle cell that leads to muscle degeneration. Patient will experience deteriorate of the their condition, and may lead to death in 30 years of age. Most of the therapy is supportive.
Concept of Gene Therapy
The concept of gene therapy is to transfer of cloned gene to the cells of people. The scientists transfer normal gene to the cells in order to replace abnormal gene. Normal gene in cell not only replace the location of abnormal gene, but may produce sufficient amount of functional protein. Another approach is by inserting suppressor gene, this gene suppress the production of abnormal protein.
There are two methods of transferring genetic material to living cells: liposomes and virus.
Liposomes is a kind of vesicle that being designed to deliver genetic material. The advantage of using liposomes is that liposomes don't elicit an immune response, but the efficiency of gene transfer may be low.
The modification of viral genome has led to the development of gene therapy vevtors with a capacity to infect tissues and integrate the genetic material but unable to replicate in cell. The advantage of using viral vectors is their ability to efficiently transfer cloned genes to a variety of human cells. However, a major disadvantage of viral mediated gene therapy is the potential to evoke an undesirable immune response when injected into a patient.
The Trials of Gene Therapy
Only few trials of gene therapy that have been done in human, most of them in laboratory settings (in vitro). In 2000, French study about gene therapy in Severe Combined Immunodefficiency (SCID) involved 10 patients. The study found 2 patient with gene therapy obtain the level of immunity comparable to normal individuals. This trial was the first clear demonstration that gene therapy can offer clinical benefit.
However, in that study 3 of 10 patients developed leukemia, after evaluation the disease is caused by integration of retroviral vector next to a particular gene in the patients.
From above, we can see that there is a hope for gene therapy that can treat the patient up to normal correction of the phenotype. But, it still needs to be study since we still lack of understanding of gene interaction in living tissues.
Most of the genetic disease occurs through embryonic development, except cancer. Eventhough, the current knowledge of inheritance of gene can predict the occurance of the disease in the offsprings, but it just percentage or chance of having the disease. Early diagnostic of certain genetic disease during embryonic period may leads to abortion in certain countries.
People who suffer the genetic disease often frustated since they will experience their abnormality for their entire life, without a chance to get away from it. The cost of the treatment is quite expensive and often supportive.
Eventhough gene therapy is still at an early stage of development, a large amount of research has already been conducted. Many of them are aimed at alleviating inherited human diseases.
Illustration of Genetic Disease
Thalassemia, is a disease that caused by abnormal protein of hemoglobin that decreases the lifespan of red blood cell. The patient with thalassemia needs monthly transfusion for entire life. And may suffering the complication of transfusion especially high iron deposit in tissues.
Duschenne Muscular Dystrophy is a disease that caused by lack of specific protein in muscle cell that leads to muscle degeneration. Patient will experience deteriorate of the their condition, and may lead to death in 30 years of age. Most of the therapy is supportive.
Concept of Gene Therapy
The concept of gene therapy is to transfer of cloned gene to the cells of people. The scientists transfer normal gene to the cells in order to replace abnormal gene. Normal gene in cell not only replace the location of abnormal gene, but may produce sufficient amount of functional protein. Another approach is by inserting suppressor gene, this gene suppress the production of abnormal protein.
There are two methods of transferring genetic material to living cells: liposomes and virus.
Liposomes is a kind of vesicle that being designed to deliver genetic material. The advantage of using liposomes is that liposomes don't elicit an immune response, but the efficiency of gene transfer may be low.
The modification of viral genome has led to the development of gene therapy vevtors with a capacity to infect tissues and integrate the genetic material but unable to replicate in cell. The advantage of using viral vectors is their ability to efficiently transfer cloned genes to a variety of human cells. However, a major disadvantage of viral mediated gene therapy is the potential to evoke an undesirable immune response when injected into a patient.
The Trials of Gene Therapy
Only few trials of gene therapy that have been done in human, most of them in laboratory settings (in vitro). In 2000, French study about gene therapy in Severe Combined Immunodefficiency (SCID) involved 10 patients. The study found 2 patient with gene therapy obtain the level of immunity comparable to normal individuals. This trial was the first clear demonstration that gene therapy can offer clinical benefit.
However, in that study 3 of 10 patients developed leukemia, after evaluation the disease is caused by integration of retroviral vector next to a particular gene in the patients.
From above, we can see that there is a hope for gene therapy that can treat the patient up to normal correction of the phenotype. But, it still needs to be study since we still lack of understanding of gene interaction in living tissues.
