Mechanism of tumor-associated macrophages promoting the progression of pancreatic cancer

Pancreatic cancer is a highly lethal disease due to rapid progression and poor response to chemotherapy and radiotherapy, and prognosis of patients with pancreatic cancer remains grim. Advances in tumor microenvironment researches uncovered the pivotal role of tumor associated macrophages (TAMs) in tumor microenvironment. Macrophages are polarized into TAMs expressing the M2 phenotype in response to the action of various cytokines and signaling pathways in the tumor microenvironment. TAMs could regulate the development of pancreatic cancer through multiple mechanisms, including promoting immune escape, fibrosis, angiogenesis, cell proliferation and cell invasion. In this study, we reviewed the mechanisms by which TAMs promote the progression of pancreatic ductal adenocarcinoma. Key words: Pancreatic ductal adenocarcinoma; Tumor microenvironment; Tumor associated macrophages; Immune escape