Newly discovered testosterone action may act on prostate cancer

Testosterone has been associated with a higher rate of certain cancers. Classically, testosterone passes through the cell membrane to act inside the cell. However recent work has indicated that testosterone may also act at the cell surface, through membrane androgen binding sites called Ambs.

Now a team lead by Professors Stournaras, Castanas and Gravanis at the Medical School of the University of Crete Heraklion, Greece, has discovered that activating these cell-surface testosterone binding sites can significantly reduce the size of prostate cancer tumours in animal models.

When testosterone is bound to another protein such as BSA, it does not enter the cell, and so can only be expressed at the cell membrane, activating newly identified specific signalling pathways. The University of Crete team treated mice, which had been given prostate cancer through inoculation with LNCaP cancer cells. They found that after one month of treatment with testosterone bound to the protein BSA (Bovine Serum Albumin) there was a 60% reduction in tumour size, with no apparent side-effects.

Professor Stournaras said:

This work strongly supports the concept that testosterone-protein conjugates, which activate membrane androgen receptors may represent a new class of experimental anti-tumour agents in prostate cancer. This is a new concept, and we need to make sure that these results can be transferred to humans in a satisfactory way. But if we can develop drugs that act safely on these Ambs (androgen membrane binding sites) then we may have a completely new therapeutic option for prostate cancer.