Transcriptomic analysis of tumor self-seeded cells, primary tumor cells, and circulating tumor cells in liver cancer

Recent studies have indicated a multi-directional seeding of circulating tumor cells (CTCs). Apart from seeding to distant tissues (cancer metastases), CTCs can also reinfiltrate and colonize already established tumors. This process of “tumor self-seeding” provides new insights into the dynamics of tumor progression, and has been indicated to promote tumor growth, angiogenesis, and invasion. Thus, therapeutic targeting of tumor self-seeded cells (TSCs) may provide effective strategies for preventing tumor progression. However, TSCs have not been well identified and characterized due to unsuitable animal models. Therefore, this study aims to develop a novel animal model to recapitulate the process of tumor self-seeding and characterize the transcriptional and functional profiles of TSCs in liver cancer. Using our tumor self-seeding model, TSCs, primary tumor cells (PCs), and CTCs were identified and isolated by fluorescence-activated cell sorting (FACS). RNA sequencing of the purified cells identified TSCs as a subpopulation of PCs. Further analyses showed that TSCs were enriched with gene sets of cancer metastasis and invasiveness, suggesting TSCs may provide novel cell targets with diagnostic, prognostic, or therapeutic potential.