| BackgroundColorectal cancer threaten the human health and is becoming more and more serious in China, which arouse broad concern. The study of colorectal cancer has found that tumor microenvironment plays an important role in tumorigenesis, it can act as the foundation of cancer cells, influence tumor evolution by regulating local immune and inflammatory response, and tumor associated macrophage is involved in that process.Macrophage which acts as an effector cells and antigen presenting cells, is an important part of human humoral immune and cell immune system, it participates in many acute and chronic inflammation reactions, Macrophages could polarize into two phenotypes M1and M2under different conditions. Recent study has shown that TAM include both phenotypes and it could act on T cells or tumor cells through complex autocrine and paracrine pathways, and is closely related to malignant proliferation and apoptosis of tumor consequently. So far, it is still not clear about the underlying mechanism of interaction between TAM and tumor cells.Inflammasome plays an important role in human immune response and inflammatory process as a part of body innate immune system, the most investigated one among which is the Nod-like Receptor pyrin domain containing-3protein(NLRP3) could provoke caspase1producing IL-1β once it was activated. Since it has been generally accepted that chronic inflammation is a important cause of tumorigenesis, relationship between inflammasome and tumor draw much attention in recent years, and some studies report that NLRP3might be potential targets in cancer treatment. NLRP3inflammasome therefore influence the tumorigenesis, invasion and metastasis.Another biochemical character of malignant tumor is a active glycolysis under low oxygen environment, which has been named as "Warburg effect", its producing ATP offers an indispensable energy supply to tumor cells despite its low efficiency compared to aerobic respiration. The glycolysis activity is regulated by several cytokines, and then influences tumor process accordingly.Here, we try to find out the influence of M2macrophage on colorectal cancer cells, and laying a foundation of the complicated regulatory mechanism between macrophage and colorectal cancer.ObjectiveTo discuss the influence of LoVo on macrophage differentiation, to induce and identify the differentiation of macrophage in vitro, we try to find out the effect of M2macrophage on LoVo biological function, and we make a further investigation of its underlying molecular mechanism.Methods1.We stimulated macrophage in vitro by using PMA and IL-4, and we identified different phenotypes of macrophage by detecting the expression of CD206, ARG1and iNOS using Western Blot and related kit2.Coculture macrophage to colorectal cancer cells by transwell3.The proliferation of cells was measured by MTT assay4.The migration capabilities was measured by scratch test5.The activity of caspasel was tested by related kits.6.The activity of PK and HK was tested by related kits.Results1.Lovo could induce the differentiation of macrophage towards M2phenotype2.We induced and identified the M2phenotype with high expression of CD206、 ARG1and low expression of iNOS 3.MTT assay showed that the proliferation of cancer cells was increasingly inhibited under the coculture environment, along with a increasing dose of adding nutrient solution which has cultivated macrophage before coculture; Scratch test showed that the migration ability of cancer cells was inhibited after coculture with macrophage4.After coculture, the caspase1activity was up-regulated in M2macrophage, while little difference was measured in colorectal cancer cells; The activity of HK, PK in colorectal cancer cells was down-regulated after coculture.ConclusionAfter coculture with M2macrophage, colorectal cancer cell LoVo showed a inhibited proliferation and migration ability, and the two key enzymes of glycolysis:PK, HK was also down-regulated, this effect may be ascribed to the activation of inflammasome pathway to produce Il-1β in macrophage. |
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