Fingerprinting prostate cancer

Two new genes which are active in prostate cancer have been identified by US researchers. At a molecular level, cancer tissue differs markedly from normal healthy tissue in its pattern of gene activity. Researchers have now developed the tools that can visualise analyse these 'molecular fingerprints' that characterise the cancerous cell. Using microarray technology, it's now possible to analyse thousands of genes in one experiments.

Doctors at the University of Michigan have now produced the first ever molecular fingerprint of prostate cancer. They examined more than 700 prostate tissue samples from more than 50 men - covering normal tissue, tissue with benign change, and also tissues from both localised and aggressive prostate cancer. They found that more than 200 genes were expressed differently between normal and cancer tissue. Of these, some are already known to be involved in cancer, while others were completely new.

Of particular interest were two genes - hepsin and pim-1. The highest levels of hepsin were found in pre-cancerous tissue just before cancer develops, and the lowest in benign prostate tissue. Hepsin play a main role in tumour development. Pim-1, a known cancer-causing gene, was also highly expressed in prostate cancer tissue. Levels of hepsin and Pim-1 were significantly linked to prognosis, when the men's clinical histories were checked.

The researchers say that the discovery of prostate cancer's molecular fingerprint could lead to many new diagnostic tests. These could offer more to the patient than the current PSA (prostate specific antigen) test and can be used as a useful diagnostic tool.