Inducible positive amplification regulation coupled with the double-strand specific nuclease for FzD5 mRNA assay

Frizzled receptor 5 (FzD5) is a significant protein receptor in the Wingless/Int-1 (WNT) signaling pathway, which plays a crucial role in the genesis and development of breast cancer. Here, we constructed a biosensor based on Inducible positive amplification regulation (IPAR) amplification mode coupled with the Double-strand Specific Nuclease (DSN) for sensitive detection of FzD5 mRNA. IPAR as a mode of gene expression regulation in prokaryotes, organically integrated the Rolling circle amplification (RCA) and strand displacement amplification (SDA) for improving amplification efficiency. By clever design, the RCA and SDA cycles were linked to each other to produce large amounts of single-stranded DNA (ssDNA). And DSN as a terminal signal output sheared perfectly paired double-stranded DNA (dsDNA) of probes and ssDNA, greatly improving the specificity of the biosensor. Taking full advantage of the IPAR mode with high amplification efficiency, the detection limit of the biosensor was as low as 99 fM. Therefore, the biosensor was a promising tool in the detection of cancer markers. And it provided new ideas for RCA and SDA applications and new application value for IPAR mode.

Automated summary

A biosensor based on IPAR amplification mode and DSN was constructed for sensitive detection of FzD5 mRNA. The biosensor, utilizing the high amplification efficiency of IPAR mode, achieved a detection limit as low as 99 fM, showing promising potential in cancer marker detection.