The Effect And Molecular Mechanism Of Cyclooxygenase-2in Tumor-associated Macrophages On Progression Of Breast Cancer

PART ITHE EXPRSSION AND CLINICAL SIGNIFICANCE OF COX-2IN TUMOR-ASSOCIATED MACROPHAGES OF BREASTCANCERObjective: To investigate the COX-2expression in TAM among breasttissue chip and analyze the correlation between the COX-2+TAM andclinicopathological features.Methods: In this study, the breast tissue chip carried160breast cancertissue specimens and10paracarcinoma tissue specimens.Immunofluorescent assay was carried out to detect the expression ofCOX-2in TAM. Paired sample t test was used to analyze the correlationbetween COX-2+TAM expression and other pathological characteristics.The Kaplan-Meier survival analysis and multivariate Cox regression analysis were used to evaluate the prognostic influences of relevantparameter.Results: Compared with that in paracarcinoma tissue, the expression ofCOX-2+TAM was increased in breast tissues (t=13.02，p＜0.001), theoverexpression of COX-2in TAM was correlated to pathology stage, clinicstage and lymph node metastasis. Moreover, the obtained data showed thatthere was a strong correlation between the density of COX-2+TAM andKi67expression (r=0.449，p＜0.001). The Kaplan-Meier survival analysisand multivariate Cox regression analysis showed that COX-2+TAMs coulddecrease the10-year overall survival and be an independent prognosticfactor for breast cancer patient outcomes.Conclusion: All foundings revealed that the increased densities ofCOX-2+TAMs were demonstrated to be an independent prognostic factorfor breast cancer patient outcomes. PART IITHE EFFECT OF COX-2+TAMS ON PROLIFERATION ANDINVISION OF BREAST CANCER CELLSObjective: To investigate the effect of COX-2+TAMs on proliferation andinvision of breast cancer cells.Methods: In this study, Human THP-1cells, after treated with phorbolmyristate acetate (PMA) and macrophage colony-stimulating factor, weredifferentiated to TAM with M2functional profiles. The COX-2gene inmacrophages was up-regulated or silenced by adenovirus vector system.After that, we investigated the proliferation, migration and invasion ofMDA-MB-231and MCF-7cells cultured alone or co-cultured with varioustreated TAM. The abilities of proliferation, migration and invasion weredetected by CCK-8kit, colony-forming assay, wound-healing and transwellinvasion assay respectively. In vivo study, the tumor weights of mice weremeasured to observe the proliferate ability of different treated MCF-7cells.Results: The colony-forming rate and the ability of migration of breastcancer cells co-cultured with TAM were higher than that cultured alone,respectively (p＜0.01). The abilities of proliferation and invasion of breastcancer cells co-cultured with COX-2+TAM were strongest than other groups, while these abilities in breast cancer cells cocultured withsiRNA-COX-2TAM were declined significantly. The vivo study alsoshowed that the tumor weight in TAM group was larger than alone group,while COX-2TAM increased this effect and siRNA-COX-2TAMdecreased it.Conclusion: All foundings revealed that the COX-2+TAM could enhancethe abilities of proliferation, migration and invasion in breast cancer. PART IIITHE MOLECULAR MECHANISMS OF COX-2+TAMINDUCING PROLIFERATION AND INVISION OF BREASTCANCER CELLSObjective: To further explore the potential mechanisms of related signalingpathways in COX-2+TAM which induced proliferation and invasion ofbreast cancer.Methods: In this part, we analyzed the activation of PI3K/Akt and ERKsignal pathway in different treated breast cancer cells by western-blot.Immunohistochemistry was used to investigate the expression anddistribution of p-Akt and p-ERK protein in xenograft tumor tissues.PI3K/Akt and ERK/MAPK signal pathways were inhibited by wortmanninand U0126respectively. Following that, we investigated the proliferationand invasion of various treated breast cancer cells by CCK-8and transwellinvasion assay.Results: The results of western-blot showed that the PI3K/Akt and ERKsignal pathways in breast cancer cells were significantly activated byCOX-2+TAM. In vivo study, the expression of p-Akt and p-ERK wasincreased in xenograft tumor tissues, where breast cancer cells were treated with COX-2+TAM, while decreased in siRNA-COX-2TAM group. WhenPI3K/Akt and ERK/MAPK signal pathways were inhibited by wortmanninand U0126respectively, the abilities of proliferation, migration andinvasion in breast cancer cells were declined as well.Conclusion: The over-expression of COX-2in TAM could activatePI3K/Akt and ERK signaling pathway, resulting in promotion ofproliferation and migration in breast cancer.