18 July 2012
Scientists at The Institute of Cancer Research (ICR) in London have identified a heritable gene variant associated with an increased risk of developing chronic lymphocytic leukaemia (CLL).
CLL is the most common form of leukaemia in Western countries, with around 3,300 people in the UK diagnosed with the disease every year. For some time it has been known that the risk of developing CLL is increased in certain families, but the genetic basis for inherited predisposition to CLL is only just coming to light.
Recent studies by the ICR team have shown that while there is no single ‘cancer gene’ for CLL, susceptibility can be explained by the co-inheritance of multiple risk variants that increase risk when inherited in combination.
Ultimately, the scientists, who were funded by Leukaemia & Lymphoma Research, hope that increasing our understanding of the inheritable genetic factors driving cancer development may help us discover new drugs or develop screening programmes that target high-risk individuals.
In a new study published in the journal Blood, the ICR team identified another key region of the genome linked to inheritance of CLL.
Studies that look for new genetic associations with diseases are known as genome wide association studies (GWAS). The scientists combined data generated by three GWAS independent studies in what is called a ‘meta-analysis’. This allowed the analysis of genetic information from 1,121 leukaemia patients and 3,745 healthy controls. As a result a new CLL ‘risk’ inherited variant was identified positioned at a very specific point on a single chromosome encoded as 6p21.33.
Study leader Professor Richard Houlston, leader of the molecular and population genetics team at The Institute of Cancer Research, said: “We investigated the combined effect of this newly found risk variation and other known CLL related variants. There was no evidence of interaction between the genes, indicating that each locus plays an independent role in increasing risk.
“These gene variations contribute significantly to the development of CLL. While risks associated with each variant are individually modest, these variations are frequently carried by individuals of European ancestry. This variant is the thirteenth that we have discovered – so while each one alone has a small effect on the risk of developing CLL, in combination these risks are important. The genetic variants we have found so far account for around 16 per cent of the inherited risk of CLL, so we believe there are more genetic variants still to be found.”
The researchers established that a strong relationship exists between the ‘risk’ locus positioned at 6p21.33 and reduced expression of the BAK1 gene found at that location. BAK1 plays a key role in the maintenance of levels of healthy immune cells, called B cells, in the blood. Deficiency in BAK1 was observed to inhibit natural cell death, leading to an accumulation of immature and mature B cells. This finding provides a fascinating insight into the biological basis of how CLL develops.
Professor Chris Bunce, Research Director of Leukaemia & Lymphoma Research, said: “This study offers more compelling evidence for the role of inheritable risk genes in hijacking the natural cell cycle. More research is needed to establish just how significant this newly discovered risk gene variant is in the development of CLL.”
Media contact: Henry Winter at Leukaemia & Lymphoma Research Press Office on 020 7269 9019, 07824 375880 or [email protected] or ICR Science Communications Manager Jane Bunce on 0207 153 5106
Notes to editors
The report is published online in the journal Blood under the title ”Common variation at 6p21.31 (BAK1) influences the risk of chronic lymphocytic leukemia”. Principal author: Professor Richard Houlston of The Institute of Cancer Research, London
Leukaemia & Lymphoma Research is dedicated to saving the lives of blood cancer patients through the promotion and assistance of research into causes, diagnosis and treatment. We are committed to advancing the interests of patients and increasing public understanding of blood cancers.
Around 30,000 people of all ages, from children and teenagers to adults are diagnosed with blood cancers like leukaemia, lymphoma and myeloma in the UK every year.
We receive no government funding and rely entirely on voluntary support. In the next five years we need to raise £120 million to continue our lifesaving work. Further information, including patient information booklets, is available from beatingbloodcancers.org.uk or on 020 7405 0101.
The Institute of Cancer Research (ICR) is one of the world’s most influential cancer research institutes.
Scientists and clinicians at the ICR are working every day to make a real impact on cancer patients’ lives. Through its unique partnership with The Royal Marsden Hospital and ‘bench-to-bedside’ approach, the ICR is able to create and deliver results in a way that other institutions cannot. Together the two organisations are rated in the top four cancer centres globally.
The ICR has an outstanding record of achievement dating back more than 100 years. It provided the first convincing evidence that DNA damage is the basic cause of cancer, laying the foundation for the now universally accepted idea that cancer is a genetic disease. Today it leads the world at isolating cancer-related genes and discovering new targeted drugs for personalised cancer treatment. The Cancer Therapeutics Unit and Drug Development Unit at the ICR and The Royal Marsden were recently honoured with the 2012 American Association for Cancer Research Team Science Award for the “tremendous impact” of their preclinical and clinical studies.
As a college of the University of London, the ICR provides postgraduate higher education of international distinction. It has charitable status and relies on support from partner organisations, charities and the general public.
The ICR’s mission is to make the discoveries that defeat cancer. For more information visit www.icr.ac.uk