Research progress and application of single-cell sequencing in head and neck malignant tumors

Abstract

Single-cell sequencing (SCS) is a technology that separates thousands of cells from the organism and accurately analyzes the genetic material expressed in each cell using high-throughput sequencing technology. Unlike the traditional bulk sequencing approach, which can only provide the average value of a cell population and cannot obtain specific single-cell data, single-cell sequencing can identify the gene sequence and expression changes of a single cell, and reflects the differences between genetic material and protein between cells, and ultimately the role played by the tumor microenvironment. single-cell sequencing can further explore the pathogenesis of head and neck malignancies from the single-cell biological level and provides a theoretical basis for the clinical diagnosis and treatment of head and neck malignancies. This article will systematically introduce the latest progress and application of single-cell sequencing in malignant head and neck tumors.

Fig. 1. Single-cell sequencing flow chart.

The main process of single-cell sequencing technology includes sample preparation, single-cell isolation, nucleic acid amplification, library construction, single-cell sequencing and data analysis.

Fig. 2. The origin of tumor and the role of tumor microenvironment.

The interaction between malignant and nonmalignant cells generates tumor microenvironment, which affects the development and invasion of cancer. Tregs inhibit antitumor immunity by killing effector T cells; Bregs inhibit B cells and promote the proliferation of Tregs by releasing IL-2 and IL-35; TAMs promote tumor angiogenesis by producing VEGF-A and EGF, and the lactic acid produced by tumor cells in turn promotes the formation of TAMs; CAFs secrete CXCL1 and CXCL8 to promote the metastasis of tumor cells; MDSCs can be activated and expanded under the action of tumor-derived exosomes (TEXs) to help tumor angiogenesis and immune escape. Tumor stem cells have the ability of self-replication and multi-cell differentiation, which is the root of tumor formation and recurrence. In the process of cancer progression, driver mutations have a selective advantage, and different subclones of each gene can show significant phenotypic variation.