Fig. 1: Proposed lncRNA regulation of IGF-1 and IGF-2.
From: Noncoding RNA actions through IGFs and IGF binding proteins in cancer
LncRNA NEAT1 increases oncogenic IGF1R signaling by competing against miRNA Let-7a, which targets IGF-2 [25]. Let-7 also potentially downregulates IGF-1 [26]. LncRNA NR2F1-AS1 can also lead to IGF1R activation by sponging miR-338-3p, which downegulates IGF-1 [27]. LncRNA CCLM interacts with the RNA-binding protein STAU-1, promoting its degradation of IGF-1 mRNA [28]. H19 suppression by promoter methylation leads to an increase in IGF-2 expression [31]. H19 also increases IGF-1 by downregulating miR-18b, which targets IGF-1 [32].
