Indentifying Epigenetic Biomarkers From Peripheral Blood of Advanced Osteosarcoma Patients, Who Recieve Famitinib and Camrelizumab Based on hMe-Seal Technique

hMe-Seal is a low-input whole-genome cell-free 5hmC sequencing method based on selective chemical labeling. It uses β-glucosyltransferase (βGT) to selectively label 5hmC with a biotin via an azide-modified glucose for pull-down of 5hmC-containing DNA fragments for sequencing. After selectively constructing 5hmC library, highthroughput-sequencing will be performed on an Illumina Nextseq-500 instrument. By ways of Rawdata processing, differential loci between Osteosarcoma group and control group will be detected to indentify specific epigenetic biomarkers of Osteosarcoma. From our previous trials, we identify geno sequencing related to beta-catenin pathways might have some relationship with osteosaroma primary or secondary drug resistance. Thus in this trial we try to further explore the drug resistance mechanism for advaced osteosarcoma second resistance to the combination therapy of Famitinib and Camrelizumab.