A method for reliable detection of genomic point mutations based on single-cell target-sequencing

Abstract

The analysis of genomic point mutations is one of the research strategies to explore the clonal evolution of tumor cells. At present, clonal evolution of tumor cells is mainly determined by bulk sampling and sequencing of different sections of the tumor. Since this approach analyzes a mixture of different cell types, it may not accurately represent the clonal evolution of specific tumor cell populations and likely miss low frequency mutations, especially when the sequencing depths are not sufficient. To address this issue, we have developed a strategy to analyze genomic point mutations from prostate basal cell carcinoma (BCC) tissues at single-cell resolution. Firstly, we optimized the single-cell whole genome amplification procedure with HepG2 cells. Then the single cells from BCC tissue were captured by a microfluidic chip of Fluidigm and processed for whole-genome amplification. Both SCUBE3 and MST1L genomic mutations were obtained by whole exome sequencing. Finally, we examined the genomic mutations through single-cell targeted amplification and Sanger sequencing. The established method successfully reconfirmed the mutations of SCUBE3 and MST1L in BCC at single cell level. The strategy established in this study could provide a useful tool for determining the clonal evolution of tumor cells based on genomic mutations at single-cell resolution.