Tumor Associated Macrophages Promote The Invasion And Metastasis In Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma(OSCC),the most common cancer in the head and neck,can cause patients to eat,language,respiratory and other dysfunction and appearance,psychological changes.Local invasiveness and distant metastasis are critical factors that associate with OSCC-related deaths.In recent years,it is well established that the tumor microenvironment(TME)contributes to cancer progression.Tumor-associated macrophages(TAMs),as the main stromal cells,can induce epithelial to mesenchymal transition(EMT)in OSCC,and show significant correlation with poor prognosis.Objective:To investigate the expression of CD68 and CD163 in OSCC and its relationship with clinicopathological features,prognosis and EMT,and to explore the possible mechanism of EMT induced by TAMs in oral cancer cells.Methods:We detected the expression of macrophages markers CD68,CD163 and EMT-related markers in 127 OSCC patients by using semi-quantitative immunohistochemistry.The relationship between the expression of these markers and clinicopathological parameters and prognosis were analyzed statistically.Then we polarized THP-1 cells to M1 and M2 type in vitro,and the phenotype was identified by real-time quantitative PCR,immunoblotting and immunofluorescence.Different inflammatory microenvironment was established and was treated with the cancer cells.The EMT-related marker expression,invasion and proliferation were detected by real-time quantitative PCR,immunoblotting,immunofluorescence,invasion assays and wound healing.The mechanism of EMT induced by TAMs in the progression of OSCC was further explored.Results:The high number of CD68-positive macrophages was correlated with poor overall survival.Meanwhile,the expression of CD 163 both in macrophages and in cancer cells was associated with poor overall survival and had a significant prognostic impact in OSCC.Importantly,CD68 and CD 163 were expressed not only in macrophages,but also in oral cancer cells,and the expression of CD 163 in oral cancer cells was significantly correlated with EMT markers E-cadherin and vimentin,suggesting that TAMs are closely related to EMT in OSCC.In vitro,the expression of CD68 on macrophages increased after stimulation with GM-CSF,and the expression of CD163,CD206 and IL10 on macrophages increased after stimulation with M-CSF.Ml-type macrophages and M2-type macrophages were established.Furthermore,the different conditioned medium(CM)was collected and was treated with the cal27.M2-type CM could induce the cancer cell undergo EMT,and enhance the cancer cells invation and metastasis.Meanwhile,addition of TGF-P cytokines to the Ml-type CM resulted in the induction of EMT and enhanced invasion and metastasis of ca127.However,the ability of EMT and invasion of oral cancer cells were decreased with the addition of TGF-? to M2-type CM.On the contrary,the EMT and invasion and metastasis ability of ca127 were decreased after addition of TGF-? inhibitor to the both M1-type and M2-type CM.Conclusions:Our results indicate that TAMs associated with the progression andprognosis of OSCC.The possible mechanism is that different inflammatory microenvironment can induce EMT in oral cancer cells and promote its invasion andmetastasis,TGF-? may play a key role in this process.