STATES CHRONICLE – A recent long term clinical trial shows that suicide gene therapy aptly fights cancer cells. The trial was carried out on prostate cancer, but it might engender a new way of treating all types of cancer.
This method presupposes that a person’s own immune system is used to kill the cancer cells. The immune system is designed to do this anyway, but cancer cells have various methods of evading its destructive influence.
Cancer is caused by erratic, incontrollable cell proliferation which is the result of some changes at the level of the genes.
Suicide gene therapy also entails the alteration of gene cells, but in a manner that determines the immune system to attack and destroy cancer. And the study has shown that this therapy, used in combination with radiotherapy and with hormonal therapy not only has produced encouraging results, but it is also completely harmless to healthy cells.
The gene therapy entailed the following steps. First, a herpes virus gene was directly introduced into the diseased cells. This gene produces an enzyme called thymidine kinase, a suicide agent.
Next, the gene started secreting the enzyme and the researchers responded by administering the patients some anti-herpes medication.
The result was that the herpes DNA was shattered and the tumor cells that had produced the enzyme began to self-destruct. Thus, the anti-herpes drug killed the herpes-containing cancer cells. The patient’s immune system was also prompted to attack the diseased cells.
The trial (1999-2003) was done with 62 males that were divided into two groups. The men in the first group had cancers restricted to the prostate, while the second group had more extensive cancers.
The first group was treated with two rounds of gene therapy and radiation, while the second group, with three rounds of the experimental therapy, radiation and hormonal therapy.
These results are far more promising than those obtained only with radiation.
Two years after the treatment, the biopsy results were negative for prostate cancer in 83% of the first group and in 79% of the second group, while after an additional three years, there was no sign of cancer in 94% of the first group and 91% of the second.
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