CXCR4+ circulating tumor cells (CTCs) accumulate in subcutaneous, immune suppressive, CXCL12-loaded-hydrogel.

CLG recovered-human lung (H460, A549), and ovarian cancer cells (IGROV-1) overexpressed the CXCL12 receptor, CXCR4, developed larger spheres and activate transcriptional programs of invasion and stemness. Interestingly, CLG-U87 glioblastoma cells highly expressed EpCAM and significantly upregulated the very specific NGFR, NTS, AQP1 and CMKLR1 genes, associated with cell proliferation, migration/invasion and metastasis.

In a syngeneic model, subcutaneous CLG significantly attracted GFP-Lewis lung carcinoma (LLC) cells impairing lung colonization within four hours from cell injection and up to twenty-one days. In lung, M1 macrophages rapidly increased post cancer cells injection while M2 prevailed after 10 days (T10). Neutrophils (Ly6Ghigh and Ly6Glow) infiltrated the lungs after ten days from cells injection with late expansion of immature Ly6Glow.