Study On The Mechanism Of M-CSF Recruitment Of Macrophages And Screen Of Genes Affecting The Prognosis In Triple Negative Breast Cancer

Objective:Triple negative breast cancer(TNBC)has become a research focus in breast cancer because of its high invasiveness,poor prognosis,and lack of targeted treatment.Tumor microenvironment(TME),as the environment for tumor growth,has a crucial effect on tumorigenesis and development.Macrophages are one of the common cells in TME,which often play a role in promoting tumors.In order to find out why TNBC has a worse prognosis than non-triple negative breast cancer(nTNBC),we first started from the perspective of TME,compared the degree of macrophage infiltration in TNBC and nTNBC,and explored the mechanism of difference;Secondly,through bioinformatics,predict differential genes in TNBC that affect patients' prognosis,with a view to laying the foundation for subsequent TNBC research.Methods:Immunohistochemical experiments were used to detect macrophage marker CD68 in cancerous paraffin tissues of breast cancer patients and mice xenografts;Transwell migration test,scratch test,and cytoskeleton staining were used to determine the ability of TNBC cells to migrate to macrophages;Use bioinformatics to predict the key genes that affect macrophage migration in TNBC and verify them in vitro.Finally,use differential gene analysis,pathway enrichment,survival analysis and other methods to perform key genes affecting TNBC patients' prognosis prediction.Results:Through immunohistochemical analysis,we found that macrophage infiltration in TNBC tissue was stronger than infiltration in nTNBC.In addition,the conditioned medium(CM)of MDA-MB-231 and HCC1937(TNBC cell lines)had a significant migration promotion effect on macrophages,while the macrophage migration promotion ability of nTNBC cell line MCF-7 was significantly weaker TNBC cells.Mechanistically,MDA-MB-231 and HCC1937 cells secreted more macrophage colony-stimulating factor(M-CSF)than MCF-7,and the secreted M-CSF promoted macrophage skeleton deformation.In vivo,there were more macrophages in TNBC transplanted tumors than nTNBC.Therefore,TNBCspecific secretion of M-CSF is an important reason for its promotion of macrophage aggregation.In addition,we predicted that the ADAM9 gene was significantly associated with poor prognosis in TNBC patients(P<0.05),and it was only related to the prognosis of TNBC patients and was not related to other types of breast cancer.Conclusion:TNBC can promote the accumulation of macrophages in TME by secreting more MCSF,and then play the role of macrophages in promoting TME;In addition,the ADAM9 gene has been shown to be related to the poor prognosis of TNBC patients.It is considered as a possible key gene that causes lymph node metastasis in TNBC patients and eventually has a poor prognosis.