Organoid-based single cell sequencing revealed the lineage evolution during docetaxel treatment in gastric cancer.

Docetaxel resistance in gastric cancer poses a major therapeutic challenge. In this study, we established docetaxel-sensitive and -resistant gastric cancer organoids and performed single-cell RNA sequencing to identify cellular and molecular alterations. We observed significant shifts in cell populations, with increased secretory, immune-chemotactic, and transitional gastric cancer cells in the resistant group. Key resistance-related genes, including FOS, IFI27, and PTTG1IP, were upregulated in resistant organoids and gastric cancer patients. A pseudo-time trajectory analysis revealed that resistant cells predominantly occupied terminal differentiation stages. Knocking down FOS, IFI27, and PTTG1IP enhanced docetaxel sensitivity in both cell lines and organoids, regulating ROS production, autophagy, and apoptosis. In vivo, silencing these genes reduced tumor growth in response to docetaxel. These findings suggest that targeting FOS, IFI27, and PTTG1IP could overcome resistance and improve treatment outcomes for gastric cancer patients.