The Mechanism Of Tumor Associated Neutrophils Adjust Thegeneration And Progression Of Gastric Cancer

Objective: To study the relationship of tumor associated neutrophils(TANs) with the occurrence and progression of gastric cancer, and its molecular mechanism.Methods: Collecting gastric tumor tissues and adjacent noncancerous tissues from 48 patients with final diagnosis of gastric cancer. Immunohistochemistry method was used to detect the number of TANs and the levels of NE and CXCL-1. The correlations between TANs and CXCL-1, NE, MMP-9, LOX, angiogenesis in gastric cancer tissues were evaluated with Pearson correlation analysis. Peripheral blood neutrophils of normal person were separated, and induced through IFN-β antibody with concentration of 5ug/ml(IFN-β antibody group) and 50% tumor cultivation mediums(tumor cultivation mediums group). The RNA and proteins of LOX、MMP-2、MMP-9 generating from neutrophils were detected using real-time PCR and ELISA. And enzymatic activity of MMP-2 and MMP-9 were analyzed with gelatin zymography assay.Results:1) Compared with the group of adjacent noncancerous tissues, the number of TANs in gastric cancer group was more, p<0.05. But the number of TANs in the group of metastasis was similar with that in the group of non-metastasis(P>0.05); the number of TANs in the group of T3T4 also was similar with that in the group of T1T2(P>0.05).2) The expression levels of NE and CXCL-1 in gastric cancer group were increased than that in group of adjacent noncancerous tissues, p<0.05. And the expression level of NE and CXCL-1 in the group of metastasis was similar with that in the group of non-metastasis(P>0.05); the expression levels of NE and CXCL-1 in the group of T3T4 was similar with that in the group of T1T2(P>0.05).3) The number of TANs were positively correlated with the expression levels of NE and CXCL-1(r=0.382,P<0.01;r=0.512, P<0.01). And the number of TANs were positively correlated with the expression levels of LOX(r=0.418,P<0.01)and VEGF(r=0.660,P<0.01). The number of TANs was positively correlated with the tumor angiogenesis(r=0.370,P<0.01).4) After induced the neutrophils from normal person with IFN-β antibody and tumor cultivation mediums, the RNA and proteins of MMP-9, MMP-2 and LOX expressing by neutrophils were higher significantly, P<0.05. The enzymatic activities of MMP-2 and MMP-9 secreting by neutrophils also stronger significantly after induced with IFN-β antibody and tumor cultivation mediums, P<0.05.Conclusions : The number of TANs was more in gastric cancer tissue than that in adjacent noncancerous tissues; the number of TANs were positively correlated with the expression levels of NE, CXCL-1, LOX, VEGF and tumor angiogenesis; when the neuphils from normal person were induced to N2 type, the amounts of MMP-9, MMP-2 and LOX secreting by neuphils were increased significantly; suggesting that the most of tumor associated neutrophils in gastric cancer were N2 type, they adjust the angiogenesis and occurrence of gastric cancer through NE, CXCL-1, LOX, MMP-2, MMP-9 and VEGF.