The somatic cells of every human are made of 46 chromosomes, two sets of 23 pairs chromosomes, each set inherited from one of our parents.Chromosomes are thread-like structures composed of double stranded DNA. The double stranded DNA is build using four types of nucleotides, each of them defined by a particular nitrogenous base: adenine (A), thymine (T), cytosine (C) and guanine (G). These nitrogenous bases pair in a specific order which makes the DNA base pairing the genetic blueprint of humans and subsequently distinguishes humans from the other species.Studies in the past have concluded that our chromosomes are made up of around 20,000 -25,000 genes. Protein formation is the main role of DNA replication and if only one of the base pairs is mutated the protein is altered and this initiates a disease.
A rich source of possibilities to identify novel disease treatments is the identification of the mutation that is responsible for the disease. Knowing the cause of the disease can allow scientists and doctors to work through the pathway and determine how the gene product is altered.After having established where the pathway was altered a gene based therapy could be use to treat the disease. There are a few approaches that can be followed to treat these types of problems among which most promising ones are:
- Gene-transfer therapy
- Stem cell therapy
Gene-transfer therapy
Gene-transfer therapy can be used to cure diseasesby inserting corrective genes into the genetic material of the diseased cells. Insertion of the wild type (non-diseased) gene would restore proper functioning of the gene and mitigate the disease.To date, there are two approaches to edit mutated genes:
In vivo approach- which means inside; mutated genes are corrected while still in the patient’s body. Using this method, wild-type genes are transferred into a patient’s affected organ, tissue or cell population and thus alleviating the disease.
Ex vivo approach- which means outside; mutated genes are corrected outside of the patient’s body. Using this method, a population of affected cells are removed from the patient’s body and are modified to carry the healthy gene and then transplanted into the patient’s body again.
Gene based therapy is not very widespread because it is still being tested in laboratories but so far it has proven to be effective and successful and it is a very revolutionary method in curing diseases nowadays.
Stem Cell Therapy
On the genetic perspective, the usage of stem cell therapy seems to be the equivalent of the modern-day organ transplantation. Unlike organs, that are composed of specialized mature cells with characteristics that are specific to the tissue found in, stem cells are immature cells which are not tissue specific and do not have specific functions yet but can divide and mature into many different tissue types.
Stem cell therapy stimulates the reparative response of dysfunctional tissue using stem cells. The principle of this therapy is similar to organ transplants using cells rather than donor organs.Stem cells are grown in the lab and then manipulated to mature into specific types of cells like blood cells, nerve cells, and heart muscle cells. When they specialize to perform a particular function cells are injected into a person. For example, a patient suffering from heart disease could get muscle heart cells injected, which then would repair the faulty heart muscle.
There is continues research dedicated to stem cells therapy but researchers have shown that adult cells from bone marrow can become heart muscle cells with the ability to repair heart tissue problems.
As gene and cell based therapies advance, multimodal strategies to cure human malady will emerge. Genetic medicine is in its early stages of development but it will require multidisciplinary methods along with collaborations, which will surely be accompanied by unanticipated, life changing innovations.
COPYRIGHT: This article is property of We Speak Science, a non profit institution co-fonded by Dr. Detina Zalli (Harvard University) and Dr. Argita Zalli (Imperial College London). The article is written by Kristjana Frangaj (Cornell University) under supervision of Dr. Detina Zalli.
References:
- Hartwell, L. H. (2011). Genetics: From genes to genomes. New York: McGraw-Hill
- Vorobice, M. E., & Valentin, F. E. (2015). Genetics and molecular biology. New York: Delve Publishing
- http://www.mayoclinic.org/
- http://www.nature.com/
- http://www.genetics.org/
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