Identification of eccDNA associated with colorectal cancer metastasis by circle-seq

The purpose of this study is to detect the differential expression of eccDNA between metastatic colorectal cancer tissue and non-metastatic colon cancer tissue through Circle-Seq.Cancer tissue samples were collected from 5 patients with colorectal cancer metastasis and 5 patients with non-metastatic colorectal cancer, DNA was extracted from the tissue samples, linear DNA was digested with exonuclease, and circular DNA was processed using REPLI-g Mini Kit (Qiagen, 150023). Carry out rolling circle amplification, use a biorupter to ultrasonic break the rolling circle amplification product to about 200-300 bp, recover the fragmented products, and use the NEBNext Ultra DNA Library Prep Kit for Illumina to build a library. Subsequently sequenced using Illumina Novaseq 6000.