Effect of targeting tumor-infiltrating myeloid cells on tumor progression in pancreatic adenocarcinoma.

298 Background: Human pancreas cancer (PC) is associated with a heavy desmoplastic reaction and influx of bone marrow derived myeloid cells. Recruitment of these cells by the tumor allows for PC to create a favorable microenvironment that is immunosuppressive. Our work demonstrates that the most abundant type of myeloid cell in PC is granulocytes, which are positive for the chemokine receptor CXCR2. This receptor is vital for the trafficking of granulocytes from the peripheral blood to the tumor, therefore selective targeting of these cells via CXCR2 blockade may lead to potential clinical benefit in patients with PC. Methods: Human samples were obtained under IRB approved protocol at Washington University.C57BL/6 mice were injected subcutaneously or orthotopically with syngeneic PC (KCKO) cells and treated with vehicle or inhibitor daily. Tumor size was determined by caliper measurements and weight. Flow cytometry was performed and samples analyzed for myeloid markers. Results: Human PC patients have ele...