Single-cell RNA-sequencing revolutionizes our understanding of cancer biology

Cancer is a difficult to treat debilitating disease with a worldwide increasing trend. Tumor cells along with the cells in the tumor microenvironment contribute to cancer. Previously, cancer biology was studied at a tissue level which masked the tumor heterogeneity and interactions between different cell types in sustaining cancer. Single-cell RNA-sequencing is a recent revolutionary technique where mRNA can be measured in each individual cell in a tissue. Thus, every individual cell in a cancer tissue could now be transcriptionally profiled to study tumor complexity. Here, we discuss three recent examples where application of the single-cell technology has provided a wealth of knowledge of tumor heterogeneity, microenvironment diversity, how a change in microenvironment enables tumor growth, and how tumor-microenvironmental interactions sustain tumors. We also discuss the current challenges and future outlook.