Sunday, December 23, 2012

Viral therapy 'completely destroys' cancer

Cancer is a disease that is hard to treat. Most therapies aim at stopping growth and attempting to decrease the size of the tumour, but there are hardly any treatments that actually cure the patient. Most famous is of course the conventional chemotherapy which kills cancer cells just a bit faster than that it kills healthy cells. Novel therapies are more targeted, and one way to achieve that is by recruiting viruses. Curiously, HIV seems effective as a treatment for cancer, but scientists are also working with other viruses, such as those that appear effective in brain cancer patients. Now, it appears science has seen another breakthrough, as a group of scientists from the University of Sheffield developed a viral therapy that 'abolishes' prostate tumours.

According to the scientists, they used a so-called oncolytic virus that specifically targets the prostate. It basically means their virus kills only cancer cells associated with the prostate. Obviously, it is impossible to simply infect a patient with a virus without thinking of the consequences. First of all, the virus may be dangerous, but secondly, the body's immune system is desperately trying to stop viral infections. Therefore, the scientists first infected a group of white blood cells with the virus, which then hitched a ride into the body.

So far, the experimental viral therapy has only been tested in a mouse model. Mice with prostate cancer were first given radiation and chemotherapy. This results in tissue damage, and this attracts cells of the immune system, including the white blood cells that were previously loaded with the viruses. These white blood cells, called macrophages, traveled to the tumour site to perform their job. Consequently, the viruses present inside the cells were able to spread and infect the remaining cancer cells, which eventually destroyed them.

The experiments with mice showed that their method 'abolishes' the tumour, which means the viruses appear to be highly effective. While the first trials with human patients are still lacking, this may actually result in a therapy that is capable of curing a patient with prostate cancer, which is quite rare for a cancer treatment. In addition, this novel attempt is especially interesting because it uses viruses in conjunction with the body's immune system to target cancer cells. Perhaps we can also use it for other forms of cancer, by using viruses that target other cell types.
HIV (blue) infecting a macrophage (green). Obviously, in the natural situation, this is bad.

No comments:

Post a Comment