Single-cell next-generation sequencing and its applications in cancer biology

A complete set of DNA with its transcripts is defined as genome, which includes both the genes and the noncoding sequences of the DNA/RNA. After making advances in decoding different genomes across species, genomic techniques such as SNP microarrays and gene expression microarray have been synchronously developed to analyze the genomic functions. Now, scientists are able to take the study of genomics into deep consideration of biological evolution and mechanism of different diseases. However, there are still challenges with the genomic technology. Some tissues of human and animals, such as tumor tissues, contain multiple heterogeneous cells, making analysis extremely difficult. Additionally, some specimens have very few cells, such as circulating tumor cells. To fully study DNA genomic changes and its expression changes in cancer, single-cell genomic techniques have been broadly applied to fields such as cytogenomic diagnosis for specimens on glass slides, tumor cells in circulating blood, measurement of sensitivity and specificity of genomic analysis at tumor tissue level, mechanism of differentiation of cancer stem cell, etc. Recently, next-generation sequencing (NGS) has become an important tool in single-cell genomic analysis. Here, we systemically introduce single-cell NGS from single-cell sampling, single-cell NGS, and single-cell NGS-related bioinformatics into its application for tumor biology. This chapteralso describes some advantages of single-cell NGS and addresses some challenges of single-cell NGS for genomics analysis due to the specimen features.