巨噬细胞STAT3途径在诱导乳腺癌免疫抑制中的作用

Role of STAT3 signal of macrophages in inducing immunosuppression to breast cancer

Objective To investigate correlation between immunosuppression effect of macrophages and STAT3 signal of cells in breast cancer.Mehtods After incubated with supernatant of culture medium of SHZ-88, a rat breast cancer cell strain, rat peritoneal macrophages were treated with tyrphostin AG490 and lipopolysaccharide. Expression of STAT3, p-STAT3 and STAT3 activity of those cells were determined. Meanwhile, cytotoxicity and antigen-presenting function of macrophages were tested.Results Expression of STAT3, p-STAT3 protein and STAT3 DNA-binding activity in macrophages induced by supernatant of culture medium of SHZ-88 cells were significantly higher than those in control group respectively, but when treated with tyrphostin AG490, protein level of STAT3, p-STAT3 and STAT3 activity was significantly lower than control group respectively; Cytotoxicity and antigen-presenting function of macrophages induced by supernatant of culture medium of SHZ-88 cells were significantly attenuated compared with control group, but when treated with tyrphostinAG490, cytotoxicity and antigen-presenting function of macrophages were significantly enhanced compared with control group.Conclusion STAT3 over-activation in tumor-associated macrophages may cause immunosuppression in breast cancer. To inhibit STAT3 signal of tumor-associated macrophages can recover and enhance the immune function of macrophages to breast cancer.