Liver activation of Hepatocellular Nuclear Factor-4α by small activating RNA rescues dyslipidemia and improves metabolic profile

Abstract Low-density lipoprotein receptor (LDL-R) is a cell surface receptor protein expressed in a variety of solid cancers including lung, colon, breast, brain and liver, therefore opens up opportunities to deliver lysosome sensitive anti-cancer agents, especially synthetic nucleic acid-based therapeutic molecules. In this study, we focused on developing novel nucleic acid molecules specific to LDL-R. For this purpose, we performed in vitro selection procedure via SELEX methodologies using mammalian cell-expressed human recombinant LDL-R protein as a target. After ten rounds of selections, we identified a novel DNA oligonucleotide aptamer, RNV-L7, that can bind specifically to LDL-R protein with high affinity and specificity (Kd = 19.6 nM). Furthermore, flow cytometry and fluorescence imaging assays demonstrated efficient binding to LDL-R over-expressed human cancer cells including Huh-7 liver cancer cells and MDA-MB-231 breast cancer cells with a binding affinity of ∼200 nM. Furthermore, we evaluated the functional potential of the developed LDL-R aptamer RNV-L7 by conjugating with a previously reported miR-21 targeting DNAzyme for inhibiting miR-21 expression. The results showed that the miR-21 DNAzyme-RNV-L7 aptamer chimera efficiently reduced the expression of miR-21 in Huh-7 liver cancer cells. As currently there are no reports on LDL-R aptamer development, we believe that RNV-L7 could be beneficial towards the development of targeted cancer therapeutics.