Recruitment Of Monocytes Into Oral Tumors Promote Formation Of Cancer Stem Cell-like Cells

Objective:Determine the recruitment of tumor associated macrophages(TAMs)in oral squamous cell carcinoma(OSCC)and detect its effect on the stem cell-like cells transformation of cancer cells.Methods:1.Transwell co-culture system was used to detect the chemotactic effect of different cell conditioned medium on monocytes(THP-1)with or without chemokine receptor inhibitor.Chemokines and M2-related markers were examined by Real-Time PCR.2.M2 macrophages induced by PMA and IL-4 were co-cultured with oral cancer cell line Cal-27.Stemness-related markers were detected with Real-Time PCR and immunofluorescence.Drug resistence and colony formation assay were conducted.Cell proliferation and apoptosis assay were detected with MTT and flow cytometry.Results:1.Compared with normal epithelial cells(Hacat)and oral cancer cell lines,cancer associated fibroblast(CAFs)could secrete more chemokines CXCL12 and recruit more monocytes.Chemotaxis decreased significantly with CXCR4 inhibitor(AMD3100).CAFs could also promote the expression of M2 related genes CD163?CD206 and Arg1.2.Compared with the control group,the expression of stemness-related genes and proteins Sox2?Oct4?Nanog?CD44 increased in co-culture group.The number of clones and drug resistence increased higher than control group.M2 could also promote proliferation and inhibit apoptosis.Conclusions:1.Cancer associated fibroblasts recruit monocytes through CXCL12/CXCR4 pathway.2.TAMs promotes the transformation of cancer stem cell-like cells.