Single-Cell Metabolomics-Based Strategy for Studying the Mechanisms of Drug Action

Studying the mechanisms of drug antitumor activity at the single-cell level can provide information about the responses of cell subpopulations to drug therapy, which is essential for the accurate treatment of cancer. Due to the small size of single cells and the low contents of metabolites, metabolomics-based approaches to studying the mechanisms of drug action at the single-cell level are lacking. Herein, we develop a label-free platform for studying the mechanisms of drug action based on single-cell metabolomics (sMDA-scM) by integrating intact living-cell electro-launching ionization mass spectrometry (ILCEI-MS) with metabolomics analysis. Using this platform, we reveal that non-small-cell lung cancer (NSCLC) cells treated by gefitinib can be clustered into two cell subpopulations with different metabolic responses. The glutathione metabolic pathway of the subpopulation containing 14.4% of the cells is not significantly affected by gefitinib, exhibiting certain resistance characteristics. The presence of these cells masked the judgment of whether cysteine and methionine metabolic pathway was remarkably influenced in the analysis of overall average results, revealing the heterogeneity of the response of single NSCLC cells to gefitinib treatment. The findings provide a basis for evaluating the early therapeutic effects of clinical medicines and insights for overcoming drug resistance in NSCLC subpopulations.

Automated summary

Studying the mechanisms of drug antitumor activity at the single-cell level is crucial for accurate cancer treatment. However, current metabolomics-based approaches are limited due to the small size and low metabolite contents of single cells. In this study, we develop a label-free platform, sMDA-scM, which combines intact living-cell electro-launching ionization mass spectrometry with metabolomics analysis, to investigate the drug action mechanisms. Using this platform, we identify different metabolic responses in subpopulations of non-small-cell lung cancer cells treated with gefitinib, providing insights for evaluating therapeutic effects and overcoming drug resistance.