Thoughts on The Differences Between Gene Therapy and Immunotherapy

As cancer medicine advances, more and more new therapies are being used to treat cancer. Gene therapy and immunotherapy are among the best. In fact, the two popular new treatments, immunotherapy and gene therapy represent two different treatment ideas, but there are also some overlaps.

Most diseases are not caused by mutations in a single gene, but by changes in the DNA sequence. But some rare genetic diseases may be caused by mutations in a single gene. Gene therapy, a relatively new treatment approach, has taken a pioneering step in treating these rare genetic diseases but remains largely experimental.

The principle of this therapy is to use genetic engineering technology to replace the faulty gene in the body that causes the corresponding disease. These genetic mutations cause cells to produce ineffective or dangerous proteins, leading to diseases such as severe combined immunodeficiency, sickle cell anemia, hemophilia, cystic fibrosis, spinal muscular atrophy and rare inherited blindness, among others.

Clinical trials of the effectiveness of gene therapy for other genetic diseases, such as severe combined immunodeficiency and blood disorders such as sickle cell anemia, are also underway.

The development of gene therapy is faster than people's imagination, and some diseases that have been helpless in the past have the hope of being cured. However, how to ensure the safety of the new therapy remains to be studied for a long time.

Most diseases are not caused by a single mutated gene (a change in the DNA sequence), but some mostly rare genetic diseases may be caused by mutations in a single gene. Gene therapy is a relatively new treatment for patients with these rare genetic diseases and is still largely considered experimental. This type of therapy aims to replace faulty genes in the body that cause disease. For example, scientists might deliver a copy of a normal gene into the body to replace a mutated gene that causes cells to produce ineffective or dangerous proteins. Some examples include severe combined immunodeficiency, sickle cell anemia and hemophilia, cystic fibrosis, spinal muscular atrophy and rare inherited blindness.

Researchers are currently testing the effectiveness of gene therapy against several genetic diseases, such as severe combined immunodeficiency, and blood disorders such as sickle cell anemia. Long-term studies are needed to prove that this method is safe. Gene therapy clinical trials at the Dana-Farber/Boston Children's Cancer and Blood Disorders Center include one for sickle cell disease and another for X-linked severe combined immunodeficiency disease.

Immunotherapy, on the other hand, is a strategy designed to improve the ability of the body's natural defense system (the immune system) to recognize and attack cancer cells. Scientists have spent decades trying to understand why the immune system -- especially specialized cells like T lymphocytes -- is sometimes successful in fighting cancer, but more often fails to recognize tumor cells or fight them effectively.

Building on major discoveries in the 1990s, scientists learned how cancer cells use natural molecules to shut down the body's immune response to tumors. This has led to insights on how to use drugs that can switch on the immune response again, harnessing its power to fight cancer.

The success of this strategy has pushed immunotherapy to the forefront of cancer research and treatment, although the treatment is only effective for a minority of patients. Several drugs known as checkpoint blockers have come into widespread use over the past few years and have had a dramatic impact on many patients with melanoma, lung cancer and other types of cancer.

One form of immunotherapy utilizes genetically modified T cells: in other words, it uses gene therapy for immunotherapy. CAR-T cell therapy uses a patient's own T cells that have been genetically modified in the laboratory to make a protein called a chimeric antigen receptor (CAR). When the modified T cells are returned to the patient, the CAR enables the T cells to seek out and destroy cancer cells anywhere in the body.