A Role Of STAT3 Signaling Of Tomor-Associated Macrophages In Immune Tolerance To Breast Cancer

TAMs are able to promote tumor growth directly by inducing immunosuppress or secreting mitogens, such as epidermal growth factor, and indirectly by stimulating tumor angiogenesis and metastasis. But the mechanism that macrophages transform from immune response phenotype to immune tolerance and pro-tumor phenotype has been poorly known. Signal transducer and activators of transcription (STATs) are cytoplasmic transcription factors that are key mediators of cytokine and growth factor signaling pathways. Recently, one of the members of the STATs family, STAT3, has emerged as a negative regulator of inflammatory responses. Targeted disruption of STAT3 signaling in macrophages resulted in priming of immune response to a tolerogenic stimulus in mice. Accordingly, in this study, we evaluated roles of STAT3 signaling of TAMs in rat immune response to breast cancer. This study was composed of three portions described as follows:1. TAMs in 53 primary breast cancers were also examined by immunohistochemistry with anti-CD68 antibodies and anti-p-STAT3...