Gene therapy attempts to fix a problem with the genetic structure or function of a cell. As one of the most promising emerging treatments today, gene therapy is actively being tested in clinical trials to treat mesothelioma and other types of cancer.
The concept behind cancer gene therapy is easy to grasp. Cancer is generally caused by a genetic malfunction or mutation of some kind that causes cells to multiply more rapidly than normal cells. Gene therapy works by replacing the faulty genes in these cells with one that work as they are supposed to.
Types of Gene Therapy
There are potentially a great many types of gene therapy available; however, in practice, only a few genetic approaches to treating cancer have shown any effectiveness. The most common approaches are summarized below.
Gene transfer works by injecting foreign genetic material into cancer cells to trigger certain effects, such as programmed death (“suicide genes”) or statis
This treatment focuses on stopping angiogenesis – the growth of new blood cells – effectively “starving” tumors. This can slow tumor growth, and in some cases even shrink the tumors.
This form of therapy uses genetically modified viruses to seek out and destroy cancer cells. These oncolytic (“cancer-killing”) viruses are designed to be harmless to healthy cells.
One of the most common ways of delivering gene therapy is through the use of viral vectors – that is, viruses that are genetically modified to attack only cancer cells. Viruses that have been used as viral vectors include adenovirus, retrovirus, lentiviruses, and vaccinia.
How Gene Therapy Can Treat Mesothelioma
Gene therapy has undergone considerable research as a treatment for mesothelioma. Although still considered to be emerging treatments, various types of gene therapy are clinical trialscontinuing to study the effects of different types of gene therapy on an ongoing basis.
Suicide Gene Therapy
One of the most interesting ways that gene therapy has been used is through triggering so-called “suicide” genes – that is, genes that cause the cell to die when activated. With one specific type of suicide gene therapy, called gene-directed enzyme-producing therapy (GDEPT), cancer cells are modified to produce an enzyme that causes their own death.
Cytokine Gene Therapy
Cytokines are proteins released by some cells that act as signals for the cells around them. Cytokine gene therapy focuses on triggering immune-related cytokines release in tumor cells, which causes the immune system to attack those cells.
Tumor-Based p53 Gene Therapy
The p53 protein is known to be defective in nearly all forms of cancer, leading some researchers to believe that the ability to repair the p53 gene sequence could be the key to finding a cure – or at least a much more effective treatment – for cancer.
Gene Therapy, Immunotherapy, and Immunogenic Therapy
While gene therapy and immunotherapy are sometimes thought of as separate forms of mesothelioma treatment, in actuality they can be one and the same thing. Gene therapy has to do with modifying genetic code, and immunotherapy uses the body’s immune to attack cancer cells.
There are some types of gene therapy that trigger the body’s immune system response, making those treatments both gene therapy and immunotherapy – or immunogenic therapy, as it is sometimes called. Cytokine gene therapy is one example of immunogenic therapy, as the purpose of the genetic modification is to induce an immune system response.
Author: Linda Molinari
Editor in Chief, Mesothelioma Cancer AllianceRead about Linda
Reviewer: Annette Charlevois
Patient Support CoordinatorRead about Annette
American Cancer Society. What’s new in malignant mesothelioma research and treatment? Cancer.org. Created May 18, 2015. Updated February 17, 2016.
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