New research published in the British Journal of Cancer has identified a link between the so-called “junk DNA” and the risk of developing cancer. Junk DNA refers to regions of DNA that don’t code for proteins but are thought to play a role in gene expression regulation. As much as 98% of our genome is composed of junk DNA, however, its exact role in disease development is still unknown. This work explored the role that junk DNA may have on regulating the genome and its association with cancer risk.

The study investigated 846 single nucleotide polymorphisms (SNPs) within non-coding regions that had been identified in previous genome-wide association studies (GWAS) to be associated with 41 cancer types. It’s difficult to interpret the biological role of SNPs in non-coding regions and fully understand how they can influence disease development, progression and response to therapy. In the population, some non-coding SNPs associated with a cancer risk are more common. However even with these SNPs, the cancer risk is only slightly increased. Other mutations found in genes such as the BRCA gene are rarer in the population, but raise the cancer risk significantly.

Looking at 13 different body tissues, a correlation was found between the SNPs and the expression of certain genes. Cancer risk SNPs were mainly identified in regions associated with oncogene expression and tumour suppressor genes, and likewise in those that regulate tissue-specific processes and immune system. These SNPs were mainly located within promoter regions of oncogenes and tumour suppressor genes and are likely to be a factor that affects its expression levels.

The researchers hope to develop AI models that can be used to better predict cancer risk and identify the areas of DNA that play a part in gene regulation. A deeper understanding of factors at play during cancer formation is crucial for the development of novel therapies.