Glioblastoma Research By Multi-region And Single-cell Whole-genome Sequencing

With higher accuracy and sensitivity,the high-throughput sequencing technology is very important to biological research nowadays.The single-cell genome sequencing develops fast,which has been applied to complicated disease research widely,from diversity of microbial system to human cancer genomics.At the nucleotide level,non-population genome studies can achieve high sensitivity and specificity.This technology will bring great prospect for the application of research achievements,by using the information from the researches,like CNVs analysis across multiple tumor samples or single cell diversity.The analysis of the single region of the tumor can not fully explain the overall mutation for the complexity of internal tumor structure,especially the functional changes in the cell level,even the same tumor may exist intratumoral heterogeneity.It is difficult to understand the tumor mechanism or to realize effective prevention and treatment of tumor diseases and treatment.Glioblastoma multiforme(GBM)is the most common malignant primary brain tumor in adults.Because of its high degree of malignancy,the rapid occurrence and development,treatment often cannot be done in time,results in a high mortality rate.The high complex mechanism of GBM,including the internal and external heterogeneity,the clone specificity changes and the regional diversity,making the clinical treatment restricted.Different GBM patients may respond to completely different sensitivities to the same treatment plan,and also have large diversity in the prognosis.Under the clinical treatment,even under the most active treatment program,including surgical resection,integrated radiotherapy and chemotherapy,Median survival rate of GBM patients usually not more than 15 months.In this study,we extracted the tumor tissue samples form 3 regional sites of from one EGFR-positive GBM patients,and isolated the single cells from the tissues.With single-cell whole genome sequencing technology,this study overcomes the limitation of intracellular heterogeneity.Totally,219 cells were separated and with whole genome sequencing.We find consistency and heterogeneity between single cells and tissues on copy number variations show clonal and sub-clone evolution.TP53 and PTEN may happen early during tumor evolution,while KIT and ERCC4 happen late.PDGFRA gene amplification and deletion,showing the differential mutation of GBM disease.We emphasized the single-cell sequencing platform finds low-frequency mutations that cannot be detected at the tissue level,revealing that this technology has important prospect for tumor-targeted drugs.