Research could lead to new prostate cancer drugs

Dr Cynthia K Miranti will investigate the mechanism that controls alterations in cells in the prostate gland and the possibility that prostate cancer arises because of some form of mistaken change happening to these cells.

This sort of 'mistaken change' has been found to be the cause of at least one type of leukemia, which can now be treated with drugs to force the cells to complete the proper change.

If Dr Miranti and her team at the Van Andel Research Institute, in Grand Rapids, Michigan, find that theory to be correct, it could lead to new drugs to fight prostate cancer being designed.

The prostate gland is composed of two layers, the lower comprises the smaller basal cells and the upper layer the larger, secretory cells.

Dr Miranti recently discovered that a hormone-like molecule called KGF could make the basal cells develop into secretory cells, suggesting that, in the healthy prostate gland, as the secretory cells wear out and die, they are replaced by cells from the basal layer undergoing this change. This discovery also suggests a possible new explanation for how prostate cancer arises.

Prostate cancer cells have some of the characteristics of basal cells and some of the characteristics of secretory cells. Should the process of changing from one cell type to another go wrong, it could create an early form of a prostate cancer cell.

Said Dr Miranti: "It is not a simple switch, multiple steps are involved when basal cells change into secretory cells.

"We are investigating which specific molecules are responsible for this change in the normal, healthy gland and trying to map the order of the events involved. At the same time, we are determining where within this sequence of events things start to go wrong to cause prostate cancer. We are doing this by looking at genes that are known to be involved in prostate cancer and examining how these genes interfere with the ability of the cells to complete the change. Very little is known about how prostate cancer initially arises and our studies will help answer that question.

"It is currently difficult to determine whether a patient's tumour will grow slowly and not harm the patient, or whether it will be more aggressive and spread around their body. One possible outcome of our studies is that we could use our findings to design treatments that "push" the tumour cells to complete the change into secretory cells, similar to what is done in some leukemia. This would greatly reduce the aggressiveness of the cancer and reduce the risk of cancer spread and ultimately, death."

Dr Mark Matfield, AICR's scientific co-ordinator said: "The more we understand about the basic mechanisms of all the different cancers, the more likely we are to find potential new ways to treat it. This is exactly what Dr Miranti has done with her important discoveries about basal and secretory cells in the prostate."

Funding is provided by a £179,532 grant from the Association for International Cancer Research (AICR).