Single cell proteomics. Potential applications in Head and Neck oncology

In-depth transcriptomic and proteomic analyses are crucial for understanding normal and pathological biology. Next-generation sequencing technology (NGS) is used to assess gene expression, but protein abundance cannot be scaled up due to the lack of methods like PCR. This presents a major obstacle to proteomics at the single-cell level, as protein expression dictates cell state. Biochemists are interested in single-cell analysis of proteins, as analyzing tissues with diverse cell types hides cell-to-cell differences, making it difficult to interpret the resulting data. Single-cell proteomics is a promising field that provides direct yet comprehensive molecular insights into cellular functions without averaging effects. However, protein adsorption loss (PAL) has been a technical challenge, and mitigations have been generic, with efficacy evaluated by the size of the resolved proteome without specificity on individual proteins. Advances in sample processing, separations, and mass spectrometry have made it possible to quantify >1000 proteins from individual mammalian cells, a level of coverage that required thousands of cells just a few years ago.