LASP1 Promotes Colorectal Cancer Progression By Enhancing M2 Polarization Of Macrophages

Background and Objective:Colorectal cancer is one of the most common gastrointestinal cancer.According to the National Cancer Center(NCC)of China in 2022,the colorectal cancer(CRC)ranks second in incidence and fourth in mortality,and its incidence and mortality are increasing year by year.Most patients with colorectal cancer are already in the middle and late stage when diagnosed,so it has important clinical significance to prevent the progression and metastasis of colorectal cancer effectively.LIM and SH3 protein 1(LASP-1)are one of the colorectal cancer metastasis-related proteins which was screened,identified and explored by our research group in the early stage,and play an important role in the occurrence,development and metastasis of colorectal cancer.Our research group has conducted a relatively in-depth exploration of its role in tumors in the early stage,but its mutual regulatory relationship with tumor immune microenvironment still needs to be further explored.In this study,we adopted a series of molecular biology and molecular pathology methods,and combined with patient tissue samples and biological methods to preliminarily explore and verify the regulatory network of LASP1 and immune microenvironment in vitro and in vivo,so as to provide a more sufficient scientific basis for elucidating the mechanism of LASP1 promoting the progression and metastasis of colorectal cancer.Methods:1.Immunohistochemistry(IHC)was used to analyze the correlation between LASP1 and tumor immune cell infiltration in colorectal cancer clinical samples.2.The changes of secreted cytokines in colorectal cancer supernatant after overexpression of LASP1 were detected by inflammatory cytokine protein chip.3.Construct the co-culture system of colorectal cancer cells and macrophage-like cells;Transwell migration and invasion assay was used to detect the effect of LASP1 on the migration and invasion ability of RKO cells.The effect of LASP1 on macrophage polarization was detected by electron microscopy.4.A mouse subcutaneous tumorigenesis model was constructed to explore the effect of LASP1 on the growth of colorectal cancer and the number of immune cell infiltration in vivo.Results:1.The expression of LASP1 was positively correlated with the number of M2 macrophages in human colorectal cancer tissue samples,and the difference was statistically significant.2.Overexpression of LASP1 promoted the secretion of macrophage-related inflammatory factor IL4 by RKO cells;KEGG analysis showed that IL14 receptorrelated signaling pathway was significantly enriched;Overexpression of LASP1 in colorectal cancer cells can induce the polarization of macrophages to M2 type.3.The effects of monocyte-induced macrophages on the migration and invasion of RKO cells were detected by transwell chamber culture method.4.The overexpression of LASP1 promotes colorectal cancer tumor growth,metastasis,and increased immune cell infiltration in vivo.Conclusion:This experimental results confirmed that the overexpression of LASP1 in colorectal cancer cells can promote tumor cells secrete inflammatory factors associated macrophage IL4,which stimulating IL4 receptor signaling pathways through inducing tumor associated macrophage to M2 polarization,M2 macrophages further promote settlement ability of invasion and metastasis of colorectal cancer cells,to promote tumor progression.