Hunt for RNA biomarkers for prostate cancer and other diseases
19 December 2013
The RIBOLUTION project in Germany is developing a platform for the identification and validation of RNA biomarkers for prostate cancer and selected diseases based on genome-spanning screening.
The project is a research alliance of five Fraunhofer institutes and supported by the Fraunhofer Future Foundation in cooperation with several universities. The project aims to identify not only RNA biomarkers, including so-called non-coding RNA, as indicators of disease, but also to monitor disease progression and predict response to therapy.
To find biomarkers the scientists compare healthy and tumorous tissue. Physicians at the University Hospital Dresden led by Prof. Manfred Wirth have been storing specimens in liquid nitrogen for fifteen years and documenting the course of the disease in patients even after they are released. They cleaved every tissue sample into 150 ultra-thin sections – each only a few thousandths of a millimeter thick – and classified them anew. There are more than 100,000 tissue sections that are unambiguously classified.
The team has sequenced the complete genome for 64 of these specimens and decoded 300,000 RNAs which has created 50 terabytes of data. They have aready found 4,000 RNAs that could turn out to be biomarkers. They will check these again against a larger group of patients and trim the selection down further.
If the results of RIBOLUTION are confirmed, then a corresponding biomarker test kit, could be on the market in few years.
Why a biomarker is needed
Diagnosing prostate cancer is currently dependent on clues provided by the prostate-specific antigen PSA, which is measured in a sample of blood. If the prostate gland is attacked by cancer, it releases more of this protein into the bloodstream. However, this test is very imprecise. If it yields an elevated value, patients have to undergo a biopsy. This involves the practitioner taking several tissue samples using a biopsy needle and having them examined by a pathologist. This entails certain risks, just like any intervention. It can lead to infections in rare cases.
If the physicians detect malignant tumour tissue in the biopsy, they usually have to remove the prostate. However, besides the aggressive form of prostate cancer, there is also a type that only grows very slowly and may not need to be operated on. It has been difficult to differentiate it from the aggressively growing tumours until now, though, so the majority of the 70,000 people in Germany who are diagnosed with prostate cancer every year are given surgery to make sure. With a better diagnostic tool, such as an accurate biomarker, some of these could be avoided.