A protein present in normal body tissue can prevent further growth in tumours, researchers have found. A tumour can grow only if its blood supply also expands to provide it with essential nutrients. The protein, discovered by Bristol University researchers, appears to block the growth of blood vessels past a certain size. The researchers hope their work, published in Cancer Research, will lead to new cancer treatments. The key protein is one of a group known as vascular endothelial growth factors (VEGF). Most forms of VEGF stimulate blood vessel growth, including the new vessels formed as a tumour begins to develop. However, the Bristol team have identified a form called VEGF 165b, which appears to have the opposite effect by inhibiting the growth of new blood vessels required for tumours to grow above one millimetre in size. The researchers have also found that this form of VEGF is generally found in many normal parts of the body, including the prostate, but not in prostate cancer.
