Many repetitive regions of the genome have been considered "junk DNA" because the technologies available did not allow them to be studied at sufficient resolution. This is the case with the SST1/NBL2 macrosatellites, considered irrelevant and, until now, virtually invisible, which could have a more complex and decisive biological role than previously thought in nuclear organization, genome regulation, chromosomal instability and even cancer.
This is the conclusion of an article published in the journal Trends in Genetics , led by researchers Sonia V. Forcales, from the Faculty of Medicine and Health Sciences at the University of Barcelona and the Bellvitge Biomedical Research Institute (IDIBELL), and Gabrijela Dumbović, from Goethe University Frankfurt (Germany).
The study, published in the Forum section of the journal, gathers evidence accumulated over years with the most recent advances in structural genomics on these largely unknown components of the human genome. Since SST1/NBL2 are primate-specific sequences, the study may also help to answer evolutionary questions about the biological function of repetitive DNA in humans and other primates.
Repetitive and altered regions in human tumours
The SST1/NBL2 satellites have been associated with cancer, particularly through epigenetic and transcriptional alterations. They are located mainly on acrocentric chromosomes (with unequal arms) and are a highly valuable model "because they concentrate many of the extreme characteristics of the human repetitive genome: they are large tandemly repeated sequences, with high structural complexity, dynamic epigenetic regulation and the production of non-coding RNAs," says Sonia V. Forcales, of the Department of Pathology and Experimental Therapeutics at the UB and principal investigator of the Immunity, Inflammation and Cancer research group at IDIBELL.
