SPARC: A programmable molecular diagnostic platform based on a signal-triggered, self-supplied crRNA and tiered PER-transcription-CRISPR cascade for early detection of hepatocellular carcinoma.

[BACKGROUND] Accurate quantification of microRNAs (miRNAs) is essential for early cancer detection, yet remains challenging due to their short length, low abundance, and high sequence similarity. Existing assays often struggle to achieve sufficient sensitivity, specificity, and robustness for reliable clinical deployment.

[RESULTS] We introduce SPARC, a programmable molecular diagnostic platform that integrates a signal-triggered primer exchange reaction, self-supplied crRNA generation, and a tiered PER-transcription-CRISPR/Cas12a amplification cascade. Using miRNA-21 as a model, SPARC achieves an ultralow detection limit of 1.22 fM and a broad quantitative range from 1 fM to 100 nM. The system exhibits high specificity, strong analytical stability, and modular adaptability to diverse targets, including miRNA-122. Notably, the dual-directional profiling of oncogenic and tumor-suppressive miRNAs enhances diagnostic resolution. When applied to HCC cell lines and clinical tissues, SPARC accurately distinguished malignant from normal samples and showed excellent agreement with qRT-PCR measurements and histopathological assessments.

[SIGNIFICANCE] This streamlined and self-amplifying cascade system provides a scalable, robust, and clinically compatible platform for ultrasensitive miRNA detection. SPARC holds strong potential for early hepatocellular carcinoma screening, molecular subtyping, and broader precision oncology applications.