“DNA-based cancer diagnosis expected to become more widespread” 

Joint team led by Professor Na Sungsoo of KU and Prof. Park Jinsung of Sungkyunkwan University develops Korea’s first highly sensitive sensor for variant cancer DNA detection
using gene scissor and nucleic acid amplification

▲ (From left) Park Hyunjun, doctoral student of Department of Mechanical Engineering; You Junseok, doctoral student of Department of Mechanical Engineering; Park Jinsung, professor of Department of Biomechatronics Engineering at Sungkyunkwan University; Na Sungsoo, professor of Department of Mechanical Engineering at Korea University

The joint research team led by Na Sungsoo, professor of the Department of Mechanical Engineering at Korea University, and Park Jinsung, professor of the Department of Biomechatronics Engineering at Sungkyunkwan University, succeeded in detecting variant cancer DNA by incorporating a gene scissor into the nucleic acid amplification process for the first time in Korea.

Supported by the National Research Foundation of Korea, the study was published online in Biosensors and Bioelectronics (Impact factor: 12.545), a top 3% journal in the field of biosensors, on January 10, 2023.

Title: Sensitive and selective DNA detecting electrochemical sensor via double cleaving CRISPR Cas12a and dual polymerization on hyperbranched rolling circle amplification

The joint team incorporated the CRISPR Cas12a gene scissor in the hyperbranched rolling circle amplification (HRCA) process, and developed a technique for detecting single point mutations or single nucleotide polymorphisms using an electrochemical sensor.

■ Hyperbranched rolling circle amplification (HRCA): A method of isothermal nucleic acid amplification that allows faster amplification through amplification in various directions.

■ Gene scissor (CIRSPR Cas12a): A protein that has caused a sensation in recent years; used to cut and paste DNA at specific locations.

The joint team conducted research into sensor development for the detection of circulating tumor DNA in the blood plasma of cancer patients for early cancer diagnosis and post-treatment monitoring.

▲ Fig. 1. HRCA process of target cancer nucleic acid and sensing mechanism of electrochemical sensor

The existing next-generation sequencing (NGS) technique is expensive and time-consuming. Variant cancers are associated with single point mutations or single nucleotide polymorphisms, and the single-stranded products. and require the use of high-performance equipment such as NGS as they are difficult to distinguish using PCR.

The team became the first in Korea to incorporate the gene scissor technique into HCRA, and applied their DNA amplification technique to detecting single-stranded HRCA products.

After detecting single-stranded HRCA products, the amplified DNA was bound to the probe DNA on the surface of the electrochemical sensor. In this way, the team succeeded in detecting variant DNA at a concentration of 10 aM (atto molar, 10-18) and showed that single point mutations can be detected at 0.01% selectivity.

Professor Na said, “Our results are expected to make DNA-based cancer diagnosis more widespread. We hope to see it being used in general hospitals and public health centers.”