Designer immune cells winning the fight against prostate cancer
By Lucy Galletly 42050050
By Lucy Galletly 42050050
Every year nearly 3000 Australian men lose their lives to prostate cancer. This dire situation could soon be coming to an end with breakthroughs in genetic engineering of immune cells appearing to have helped two advanced prostate cancer patients. Prostate cancer is very volatile, spreading quickly and often not being stopped via the removal of the prostate. This makes complete eradication difficult, which makes this possibility of a complete cure a definite bright spot on the horizon of cancer research.
Modified T Lymphocyte immune cells attacking prostate cellsThe breakthrough was made by genetic re-engineering of the patients’ T lymphocytes (commonly referred to as T cells), a type of white blood cell(See above picture). The rationale behind the re-engineering was that white blood cells rapidly fight infections in the body. The researchers inserted genes which target prostate cells into the white blood cells by means of a virus. The re-engineered T cells recognize a protein called prostate-specific membrane antigen (PSMA) found exclusively on the membrane of prostate cells and can therefore exclusively target these cells.
The study would not have been possible until recently, due to the short life span of a T cell. Recent research has found a solution to this problem: patient’s bodies are given chemotherapy which depletes the white blood cell count and thus makes room for new T cells in the body – this allows the re-engineered cells to stay months or even years in the body’s system.
There are definite safety and expense issues regarding this seemingly miracle research. One issue is that, while the T cells are designed to attack only prostate cells, the intervention is using a ‘living drug’ that cannot be removed from the body is a cause for concern, e.g., it is possible that the T cells could attack other healthy cells and organs in the body. While it can be counter-acted by keeping the modified T cell count low, this would also decrease effectiveness. A further issue is the expense of these personally designed immunity cells, with leading immunotherapy researcher Mark Dudley (2005) saying that until guarantees of success are 100% it isn’t a viable medical path.
While there are certainly some negatives and uncertainties with regard to this innovative cure for prostate cancer, this advantageous breakthrough does seem to hold potential for the future, perhaps not just for prostate cancer, but for a whole range of cancers.
Article Reviewed:
Powell, K. (2009) “Designer Immune Cells Fight Prostate Cancer”, Nature.
Reference:
Dudley, M. E. et al. (2005) “Adoptive Cell Transfer Therapy Following Non-Myeloablative but Lymphodepleting Chemotherapy for the Treatment of Patients With Refractory Metastatic Melanoma” Journal of Clinical Oncology. 23(10), 2346-2357.
