Systematic Design of Multiplex Methylation-Specific qPCR for Cancer-Related Biomarkers

Analysis of circulating cell-free DNA (cfDNA) methylation abnormalities has emerged as a powerful strategy for detecting various diseases, particularly cancers. This study demonstrates a process for developing a multiplex methylation-specific qPCR assay for cancer biomarker detection. AbstractAnalysis of circulating cell-free DNA (cfDNA) methylation abnormalities has emerged as a promising strategy for detecting various diseases, including cancer. While single-biomarker approaches may lack sensitivity, comprehensive next-generation sequencing (NGS) can be cumbersome and expensive. Multiplex methylation qPCR assays offer a practical intermediate solution by providing accurate, accessible, and affordable methylation biomarker detection. In this study, we demonstrated a process for developing a multiplex methylation-specific qPCR assay using colorectal cancer (CRC) methylation biomarkers as a case study. Starting with a set of CRC methylation biomarkers, we developed the Multiplex Methylation-specific qPCR (MMqPCR) algorithm to scan differentially methylated regions (DMRs) for methylation-specific PCR primer and probe design. We then established a systematic process to eliminate assay cross-reactions, reduce background noise, and assess multiplex compatibility. Using a low concentration of hypermethylated DNA (0.1%) in a digital analysis, we demonstrated a 95.8% detection rate with the multiplex strategy, significantly outperforming the singleplex approach (47.9%). The multiplex qPCR development principles and automated primer design algorithm presented here provide valuable tools for developing disease screening, detection or monitoring methods based on methylation analysis.