"Up until about two decades ago, one type of RNA, called microRNA, or just miRNA – by virtue of them being very short, only 18-25 letters long – were thought to be the junk mail of the genome, with no biological function. But today we know that these miRNA are actually not junk but play a very important role in regulating the activity of other parts of your DNA.
it turns out that the 98% of our genome that was regarded as “junk” might have a function after all.
The second miRNA was not discovered for another seven years. But since then, more than 1,800 human miRNAs have been found. We now understand that miRNA control numerous genes and processes vital for cellular life such as metabolism, development and the immune system.
One promising application of miRNAs is their potential as biomarkers and therapeutics in cancer.
A 2002 study found two miRNAs were deleted in 68% of chronic lymphocytic leukemias."
Pamela Ajuyah, PhD student in molecular biology and Nham Tran, Lab Head at University of Technology, Sydney explain more of how microRNA (miRNA) functions and how our growing understanding of how they function "suggests that the future of cancer therapy may lay with miRNA-based drugs that can target multiple genes, and therefore affect multiple pathways involved in cancer. This moves us on from the “one drug, one target” approach."