Fig. 3

Induction and formation of LNM by FAO. FAO is implicated in multiple aspects of tumorigenesis including cancer cell growth, survival, drug resistance, and metastasis. Once migration into circulation system, the first challenge for the survival of cancer cells is to restrain apoptosis and cancer cells utilize fatty acids to fuel the growth. Then, FAO in tumor-associated immune cells and endothelial cells is also reprogrammed to contribute to immune suppression and the formation of tumor-promoting microenvironment. Lymph nodes are induced by cancer cells to establish pre-metastatic niches where FAO is involved in lymphangiogenesis, the recruitment of immunosuppressive cells, the up-regulation of chemokines and cytokines as well as vascular remodeling, indicating that FAO may play roles in formation of lymph node pre-metastatic niches. Once cancer cells colonize within lymph nodes, LNM is formed successfully