Application of CRISPR/Cas9-based mutant enrichment technique to improve the clinical sensitivity of plasma EGFR testing in patients with non-small cell lung cancer

Cancer Cell International

Boyeon Kim¹  Kyung-A. Lee¹  Yoonjung Kim¹  Seung-Tae Lee²  Saeam Shin²  Jae Yong Cho³ 

[1] Department of Laboratory Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine;Department of Laboratory Medicine, Yonsei University College of Medicine;Division of Medical Oncology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine;

关键词: Cell-free nucleic acids;    EGFR gene;    Liquid biopsy;    CRISPR-Cas System;    Non-small cell lung cancer;   

DOI  :  10.1186/s12935-022-02504-2

来源: DOAJ

【 摘 要 】

Abstract Background Approximately 50%–60% of secondary resistance to primary EGFR- tyrosine kinase inhibitors (TKI) therapy is caused by acquired p.Thr790Met (T790M) mutation; however, highly fragmented, low-quantity circulating tumor DNA is an obstacle for detecting mutations. Therefore, more sensitive mutation detection techniques are required. Here, we report a new mutant enrichment technology, the CRISPR system combined with post-polymerase chain reaction (PCR) cell-free DNA (cfDNA) (CRISPR-CPPC) to detect the T790M mutation using droplet digital PCR (ddPCR) from cfDNA. Methods The CRISPR-CPPC process comprises the following three steps: (1) cfDNA PCR, (2) assembly of post-PCR cfDNA and CRISPR/CRISPR associated protein 9 complex, and (3) enrichment of the target DNA template. After CRISPR-CPPC, the target DNA was detected using ddPCR. We optimized and validated CRISPR-CPPC using reference cfDNA standards and cfDNA from patients with non-small cell lung cancer who underwent TKI therapy. We then compared the detection sensitivity of CRISPR-CPPC assay with the results of real-time PCR and those of ddPCR. Results CRISPR-CPPC aided detection of T790M with 93.9% sensitivity and 100% specificity. T790M mutant copies were sensitively detected achieving an approximately 13-fold increase in the detected allele frequency. Furthermore, positive rate of detecting a low T790M copy number (< 10 copies/mL) were 93.8% (15/16) and 43.8% (7/16) for CRISPR-CPPC assay and ddPCR, respectively. Conclusions CRISPR-CPPC is a useful mutant enrichment tool for the sensitive detection of target mutation. When tested in patients with progressive disease, the diagnostic performance of CRISPR-CPPC assay is exceptionally better than that of any other currently available methods.

【 授权许可】

Unknown