A better understanding of the genetic factors that contribute importantly to the risk of cancer will serve to perfect screening.
How much part, of the risk of getting cancer during life, is hereditary? Research by the University of Stanford brings an important contribution to the answer to this complex question, identifying just under 400 genetic variants present since conception which are essential to trigger or feed the growth of tumors.
According to the study, published on Nature Geneticsunderstanding better which genetic factors affect more than others on the predisposition to cancer could improve prevention, for example by refining the screening that evaluate the individual risk of developing certain types of tumors.
Synthesis work. “We summarized great collections of information from millions of people to whom any of the 13 most common types of cancer was diagnosed, which make up over 90% of all human neoplasms”, explains Paul Khavari, doctor, researcher and professor of dermatology to the Stanford Medicine. «This enormous contribution of data has allowed us to identify 380 variants that control the expression of one or more genes associated with cancer. Some variants, if you are unlucky enough to inherit them by the parents, can increase the risk of developing many types of cancer »continues Khavari, the first author of the study.
Always there. Compared to most of the studies on cancer and genetics, the new work has focused on the genetic sequences inherited at the time of conception, that is on the germtransmitted to birth, and not on the mutations that can be accumulated in the course of life with subsequent cell divisions. Example of the mutations sought by scientists are those on the BRCA1 and BRCA2 genes, which if present give a much higher risk of getting sick or ovary cancer. At the moment, in fact, few mutations are known so predictive for the development of tumors.
Traffic lights for genes. The almost 400 variants identified they are not found on coding genesthat is, codify the instructions to produce proteins. Instead, they are in the regulatory regions that control if, when and how genes are expressed In many cases close, in rarer cases in a distant region of DNA. These are variants at the level of a single nucleotide (SNV, single-nucleotide variants), DNA changes concerning nucleotides, that is, the repetitive units that constitute our genome.
Compared data. The authors of the study have studied more than 4000 genetic variants associated with cancer in previous associations on the whole genome (which establish what frequently appear certain variants in people with certain types of cancer, compared to people without cancers) to understand how much they were able to alter the genetic expression in the cells of 13 types of cancer – For example by testing the variants associated with lung cancer in human lung cells.
Cellular cleaning and inflammation. Some of the variants identified are involved in biological paths that concern cell death, such as cells interact with the surrounding environment or how they repair their DNA. Others regulate the functionality of the mitochondria, the energy plants of the cells, still others the inflammatory processes. “We expect this information to be incorporated In increasingly information genetic screening tests Which will be available in the next decade to help determine those who are most at risk for many types of genetically complex diseases, including cancer “, concludes Khavari.
