DNA structure may signal prostate cancer

Scientists at the Pacific Northwest Research Institute (PNRI), Seattle, US, have identified a DNA structure that could signal a high-risk for prostate cancer, and are touting it as a new biomarker for assessing prostate cancer risk and as a target for early intervention.

Working with cancerous prostate tissues of men over 55 years of age, the researchers found the DNA phenotype, which appears to be structurally stable having been confirmed as present in 'normal' tissues surrounding tumours, to be indistinguishable from the DNA structure identified in prostate tumours.

Lead researcher, Donald C Malins, says that 'the potential exists to inhibit or eliminate this cancer DNA phenotype with drug intervention, thereby reducing the risk for prostate cancer'.

Previous studies by the PNRI found mice injected with a known carcinogen to produce a comparable cancer DNA phenotype around eight weeks prior to tumour development. This phenotype was able to be 'virtually eliminated' and tumour formation was able to be 'substantially delayed' through intervention with cyclophosphamide.

Malins said that all the findings 'support the concept that cancer risk can be predicted by identifying the cancer DNA phenotype in normal tissues, long before any tumours appear. Exposure to oxidising chemical species, such as free radicals, that form in the body from environmental and/or dietary exposures to toxic chemicals are likely contribute to the development of the cancer DNA phenotype.'

The next step for the PNRI is to demonstrate that the phenotype can be used by physicians to predict the risk of prostate cancer. Drugs will also be assessed for their ability to eliminate or delay the formation of the phenotype before tumours start to form.