Apostle MiniMax technology has been applied in world-class research and development projects of novel liquid biopsy technologies. Some examples include:
Multiplex assays, involving the simultaneous use of multiple circulating tumor DNA (ctDNA) markers, can improve the performance of liquid biopsies so that they are highly predictive of cancer recurrence. We have developed a single-tube methylation-specific quantitative PCR assay (mqMSP) that uses 10 different methylation markers and is capable of quantitative analysis of plasma samples with as little as 0.05% tumor DNA. In a cohort of 179 plasma samples from colorectal cancer (CRC) patients, adenoma patients, and healthy controls, the sensitivity and specificity of the mqMSP assay were 84.9% and 83.3%, respectively. In a head-to-head comparative study, the mqMSP assay also performed better for detecting early-stage (stage I and II) and premalignant polyps than a published SEPT9 assay. In an independent longitudinal cohort of 182 plasma samples (preoperative, postoperative, and follow-up) from 82 CRC patients, the mqMSP assay detected ctDNA in 73 (89.0%) of the preoperative plasma samples. Postoperative detection of ctDNA (within 2 wk of surgery) identified 11 of the 20 recurrence patients and was associated with poorer recurrence-free survival (hazard ratio, 4.20; P = 0.0005). With subsequent longitudinal monitoring, 14 patients (70%) had detectable ctDNA before recurrence, with a median lead time of 8.0 mo earlier than seen with radiologic imaging. The mqMSP assay is cost-effective and easily implementable for routine clinical monitoring of CRC recurrence, which can lead to better patient management after surgery.
We developed a computational program whereby available SD regions can be processed and analyzed efficiently for their potential use as biomarkers of the aneuploidy of interest. For the five common aneuploidies, i.e., trisomy 13, 18, 21, and two sex chromosome aneuploidies, a total of 21,772 candidate SD biomarker sequences together with their corresponding primer/probe sets were generated. The primer/probe sets were tested using a real-time PCR-based multicolour melting curve analysis for simultaneous detection of the five common aneuploidies, and yielded 100% clinical sensitivity and 99.64% specificity when subjected to a clinical evaluation. Following the observations that the SD biomarkers for aneuploidy could be better detected by digital PCR with improved accuracy, we established a noninvasive prenatal testing protocol for trisomy 21 and attained 100% concordance with next generation sequencing.
Our study confirmed that SD regions are preferred biomarkers for aneuploidy detection and in particular SD-based digital PCR could find potential use for NIPT of trisomy. A similar strategy can be applied to other chromosomal abnormality and genetic disorders.
