Gene link to higher rates of bowel cancer in men
Scientists have shown for the first time that one of the sex chromosomes is involved in the development of a cancer that can afflict both genders. The finding may help explain why men have higher rates of bowel cancer than women.
The international collaboration - led by Professor Richard Houlston at the ICR, along with the University of Oxford and Edinburgh University – carried out a genome wide association study to find changes to the DNA code that increase the risk of bowel cancer. For the first time, they identified an alteration on the x-chromosome, one of two chromosomes that determine gender.
The ‘faulty’ region on the x-chromosome is linked to lower levels of a gene called SHROOM2 that controls how cells develop and take shape. Mutations in this gene have previously been linked to cancer.
The scientists have suggested that in women, the ‘faulty’ x-chromosome version is hidden by a normally-functioning version. But in men, who only have one copy of the x-chromosome, there is no normal version to mask this ‘faulty’ copy.
The discovery of the x-chromosome link, along with a further two risk variants, brings the total number of regions on the genome found to increase the risk of bowel cancer to 20.
The second variant found in this study is within the CDKN1A gene on chromosome 6, while the third variant discovered is located on chromosome 11, within a gene called POLD3.
