Certain genetic breakdowns or mutations in the DNA code of some cells lead to cancer in the human body. Some gene mutations are inherited. Others are acquired. Finding a mutation, you can choose the right medicine to destroy the tumour. To find it, it is necessary to conduct an in-depth study of the tumour genome.
What kinds of cancer can be treated by gene therapy?
Rituximab was the first drug implemented in gene therapy, its effectiveness was observed in the treatment of lymphoma and leukemia. Trastuzumab is an antibody that is used in breast cancer treatment. More specifically, it is used when the HER2 gene is detected. This kind of cancer is very aggressive and is peculiar with an unfavourable prognosis. Nonetheless, Trastuzumab helps to lengthen the life expectancy of patients suffering from this cancer.
Small-molecule drugs are another stage of gene therapy evolution. Therefore, it is becoming possible to effectively treat:
Over the past few years, studies have been conducted to determine the genetic profile of malformations. A genetic profile identifies specific gene mutations. Specific drugs are created in response to these mutations, which increases the life expectancy of patients for many years.
The following diseases are treated this way:
- Prostate cancer
- Ovarian cancer
- Brain cancer
- Lung's cancer
- Mammary gland cancer
- Nasopharyngeal carcinoma
- Bladder cancer
- Colorectal cancer
- Malignant mesothelioma
- Thyroid gland cancer
- Acute leukemia
- Oesophageal carcinoma
- Pancreatic cancer
- Bone cancer
New methods of gene therapy are being developed to hopefully cure many other malignant tumours. However, they are not yet implemented in medical practice and are still considered to be at a trial stage.
Gene therapy principle
When a changed or absent gene is detected the following treatment guidelines are applied:
- Replacement of the damaged DNA
- Block the mutated gene and stop the cell division
- Stimulation of the immune system, which effectively destroys atypical cells that have a specific gene mutation
- Insertion into the cells of “suicide genes” that cause cancer cells to self-destruct
- Introduction of “labelling genes” making cancer more susceptible to chemotherapy
Currently, the latest gene therapy involves the use of vectors to deliver new genetic material into the cells. Vectors can be viral and non-viral. Viral vectors presuppose the administration of viruses into the organism. Viruses build into the tumour cells and change its genetic material. Such vectors are used in the majority of cases.
Non-viral vectors are:
- DNA transfection means that genetic material is absorbed by cells and penetrates into the nucleus, where it is later subjected to transcription and translation.
- Gold-coated micro-particles coated with DNA increase the efficiency of the transfection.
- Liposomes means that DNA is placed into the organelle for its delivery to tissues. This way, you can enter large fragments of genetic code.
- DNA complexes with polymers means DNA is combined with some molecules, and then injected into the body. Polymers are destroyed in the blood and the DNA penetrates into the cells. The possibility of using this vector for brain cancer treatment is being explored.
Most non-viral vectors areo used only as models of cell cultures or in laboratory animals, and are not yet used in clinical practice.
Promising gene technology CRISPR / Cas9 has been used in the USA since 2016. Special enzymes are introduced into the body. The damaged DNA fragments are "cut out", determining them by the genetic code.
Where is gene therapy applied?
Gene therapy is applied in some medically advanced countries. It has attracted many people who are determined to get results, when the current treatment doesn't help. Some famous people who have had success with gene therapy, include, Jimmy Carter, the former US president. He has successfully cured cancer with gene therapy in Multicare Hospital in Gig Harbor, Washington.
In Israel some kinds of gene therapy are applied as experimental treatment method in the following hospitals:
German Eppendorf hospital uses individual gene therapy for prostate cancer treatment. After an analysis of tumour cells, DNA, and detection of mutations, individually selected drugs are used to block the damaged genetic sequences.
Gene therapy is one of the most promising areas of oncology. Researchers believe that with its help it will be possible to control even the most aggressive forms of oncologic diseases at the advanced stages. The diagnosis of cancer will no longer be a verdict. It will become just one of many chronic diseases - dangerous, sometimes incurable, but not fatal.
Choose treatment abroad and you will for sure get the best results!
Author: Dr. Nadezhda Ivanisova