1.3.1 LncRNA represses miRNA expression
LncRNA bind with miRNA and suppress its expression by common binding sites, or lncRNA directly suppressing miRNA precursors or primary miRNAs, thereby lowering transcription product creation. Lnc-PFAR stems pre-miR-141 maturation by binding with pre-miR-141 in 72 Nucleotide binding domain, thus reducing miR-141 expression[15]. Rather than direct bind and interact with mature miRNA, lnc uc.173 combined with pri-miR-195 in its central stem region, destabilizing and enhancing degradation of pri-miR-195, thus inhibiting Dorsha-mediated pri-miRNA processing to pre-miRNA, and deregulate the expression of miR-195[16]. In addition, the binding of lncRNA to miRNA, or miRNA binding sponge, exerts a role in inhibiting miRNA function, while further affect the mRNA levels of miRNA downstream targets, and this mechanism of interaction by competitively binding miRNA to mRNA is known as the ceRNA mechanism.