An international team of scientists has discovered that x-chromosome - one of two chromosomes that determine gender - is involved in the development of cancer. They discovered this when they analysed changes in DNA code that increases the risk of bowel cancer.
"To our knowledge, this is the first time that anyone has shown that one of the sex chromosomes is involved in the development of a cancer that can afflict both sexes. This may help explain why bowel cancer is slightly more common in men. Ultimately, it could also help us target screening to those who are more at risk of the disease," said Professor Richard Houlston, researcher at the Institute of Cancer Research, in a statement.
Scientists have found a "faulty" region on the x-chromosome is linked to lower levels of a gene called SHROOM2. The SHROOM2 gene controls how cells develop and take shape. Mutations in this gene have previously been linked to cancer.
To identify this gene scientists had studied Single Nucleotide Polymorphisms (SNP) - pieces of DNA that vary between individuals - from five previous international studies. They were studying SNPs among a group of people who had cancer. They found that this gene played a major role in the development of bowel cancer.
Bowel Cancer is a cancer that starts in the large intestine or rectum. Bowel Cancer is also known as colorectal cancer. Bowel cancer starts in the lining of the colon and the rectum. The cancer is the third most common cancer in the UK - each year around 41,000 people are diagnosed with the disease, around 22,700 men and 18,400 women.
To identify these genetic alterations the researchers studied SNPs (single nucleotide polymorphisms) - pieces of DNA that vary between individuals - from five previous international studies, looking for SNPs that were more common in cancer cases than healthy individuals.
The second variant found in this study is within the CDKN1A gene on chromosome 6. CDK1NA codes for a protein that is a key controller of a number of tumour suppressor pathways in the cell. It also blocks the creation of new strands of DNA which is needed in cancer cells as they grow and divide.
The third variant discovered is located on chromosome 11, within a gene called POLD3. This gene plays a key role in two pathways that repair DNA damage, and which are defective in some bowel cancers.
"Cancer Research UK funded scientists have led the world in discovering genes that increase the risk of bowel cancer. This research adds to this understanding and shows how a range of genes could be behaving in bowel cancer, potentially leading to new treatments for the disease," said Dr Lesley Walker, director of cancer information at the Cancer Research UK, in a statement.