What role does the enzyme DICER play in miRNA biology?

DICER is a ribonuclease enzyme that is essential for the maturation of miRNA. In the cytoplasm, DICER cleaves the pre-miRNA stem-loop into a short RNA duplex of approximately 22 nucleotides. One strand of this duplex becomes the mature, functional miRNA that is loaded into the RISC complex to regulate target mRNAs. DICER function is dysregulated in many cancers — and interestingly, reduced DICER activity can paradoxically lead to overexpression of certain oncogenic miRNAs while reducing tumor-suppressive miRNAs, contributing to the cancer-associated miRNA expression patterns that OncuraKit detects. Mutations in DICER itself have been associated with a rare inherited cancer syndrome (DICER1 syndrome) affecting multiple organ systems.