2.1 Murine tumor model

The murine oral cancer (MOC) model is a carcinogen-induced model of oral cavity cancer that is transplantable into fully immunocompetent C57BL/6 (B6) mice [9]. MOC1 cells were provided by Dr. R. Uppaluri (Washington University School of Medicine). MOC cells were cultured as previously described [10]. All animal experiments were approved by the NIDCD Animal Care and Use Committee (ASP #1364-14). To generate syngeneic tumor-bearing mice, 4×10⁶ MOC1 cells were injected subcutaneously in matrigel into the flank of WT C57BL/6 (B6) mice. Tumors were engrafted and allowed to reach at least 500 mm³ before MDSC isolation.