Single-Cell Multiplexed Signal Amplification Strategy Based on Catalytic Hairpin Self-Assembly and CRISPR/Cas12a for Exploring the Relationship between lncRNA HOTAIR and miRNA-122 in Individual Hepatocytes.

The long noncoding RNA (lncRNA) HOTAIR has been shown to act as an oncogene in a variety of cancers, including hepatocellular carcinoma (HCC). MicroRNA-122 (miR-122) is a key liver-specific miRNA that is frequently inhibited in HCC and is associated with poor prognosis. However, a potential relationship between HOTAIR and miR-122 in individual hepatocytes has not been explored. To this end, we propose here an intracellular catalytic hairpin self-assembly-CRISPR/Cas12a tandem multiplexed signal amplification strategy for the simultaneous quantification of HOTAIR and miRNA-122 in a single hepatocyte. We applied this method to analyze both normal HL-7702 liver cells and HepG2 HCC cells, and found that HL-7702 cells contained large amounts of miRNA-122, while the content of miRNA-122 in HepG2 cells was low. However, the level of HOTAIR in HepG2 cells was much higher than that in HL-7702 cells, confirming the overexpression of HOTAIR in HCC cells. We achieved the simultaneous absolute quantification of HOTAIR and miRNA-122 in single cells, providing an important method to study the relationships between these two RNA molecules in individual cells.