Coupled with chemotherapy, suicide gene therapy has the ability to effectively destroy prostate cancer cells, according to new research out of Houston Methodist Hospital.
The idea behind coupling the two treatments is based on the belief that genetic modification of cancer cells can boost the effectiveness of chemotherapy, which in this case – is true.
In suicide gene therapy, self-destructive genes that trigger the body’s immune system to attack them are introduced into tumor cells, which green-lights the cells for eradication.
Cancer researchers behind the study, which was published on December 12 in the Journal of Radiation Oncology (JRO), compared two groups of patients — those with cancer confined to their prostate and those with aggressive prostate cancer — and found the addition of suicide gene therapy to improve the overall 5-year survival rates of both groups. The overall survival rates after five years were 94 and 97 percent.
E. Brian Butler, MD, senior author of the recently published paper, was quoted by EurekAlert as having explained that he and colleagues “strategically” introduced a herpes virus gene producing the enzyme thymidine kinase (TK) which, once delivered, was treated with an anti-herpes drug that attacked both the herpes DNA as well as the TK-producing tumor cells.
We strategically used an adenovirus, similar to the one that causes the common cold, to carry the therapy agent–a herpes virus gene that produces the enzyme thymidine kinase, or TK–directly into the tumor cells (…) Once the herpes virus gene was delivered and it started manufacturing TK, we gave patients a commonly used anti-herpes drug, valacyclovir. The combination attacked the herpes DNA, and the TK-producing tumor cells self-destructed, which is why the procedure is called ‘suicide gene therapy.
This type of gene therapy, according to the researchers, shows promise for treating prostate cancer patients with radiotherapy as well as with or without hormonal therapy.
This is extremely pleasing to us, considering we had patients enrolled in our protocol after other physicians deemed them incurable (…) We firmly believe this will be a viable treatment strategy.
Some of the patients involved in the study had been previously deemed “incurable” by other physicians, according to the paper’s lead author Bin Teh, M.D., vice chair of Houston Methodist’s Department of Radiation Oncology.
Dr. Teh noted that the trial’s participants experienced little to no side effects or complications as a result of the combined therapies.
Butler was quoted by United Press International as having said that he and his colleagues “have created a vaccine with the patient’s own cancer cells, a treatment that complements, and may even enhance, what we can achieve with traditional radiation and hormonal therapies.”
We have created a vaccine with the patient’s own cancer cells, a treatment that complements, and may even enhance, what we can achieve with traditional radiation and hormonal therapies
Researchers conducted a study unrelated to Houston Methodist’s recently reported that high doses of vitamin C can kill mutated tumor cells.