A study on the correlation between M2 macrophages and regulatory T cells in the progression of colorectal cancer

Abstract

Background M2 macrophages and regulatory T cells (Tregs) can promote tumors and development by inhibiting the anti-tumor immune response. This study investigated the effect of CD163-positive M2 macrophages and Foxp3-positive Tregs in the progression of colorectal cancer and lymph node metastasis. It also investigated the correlation between M2 macrophages and Tregs. Methods Postoperative tissue specimens and clinical data were collected from 197 patients with colorectal cancer who underwent initial surgical treatment in The Second Ward of Colorectal Surgery of the First Affiliated Hospital of Jinzhou Medical University from March 2020 to December 2020. Immunohistochemical methods were used to detect the expression levels of CD163 protein-labeled M2 macrophages and Foxp3 protein-labeled Tregs in colorectal cancer tissues, matched paracancer tissues, and lymph node tissues. The correlation between CD163 and Foxp3 in cancer tissues and lymph node tissues were analyzed, as well as the relationship between clinicopathological characteristics and preoperative tumor markers. Results M2 macrophages and Tregs were importantly positively correlated in cancer and lymph node tissues, which significantly increased in cancer and metastatic lymph node tissues. Interestingly, M2 macrophages in non-metastatic lymph nodes also increased significantly in patients with metastatic lymph nodes. In addition, both CD163 and Foxp3 were upregulated with increasing tumor node metastasis stage, depth of infiltration, and lymphatic metastasis; and both were positively correlated with carcinoembryonic antigen. Conclusion CD163 may be a good predictor of pre-metastatic status of colorectal cancer lymph nodes. carcinoembryonic antigen affects the distribution of M2 macrophages and Tregs in colorectal cancer. There is a certain correlation between the two types of cells. It is possible that M2 macrophages, together with suppressor Tregs cells, promote an immunosuppressive environment.

The Role of Regulatory T Cells in Cancer Treatment Resistance

“…TAMs are one of the main mediators of immunosuppression, next to Tregs [ 49 ]. They suppress Teff’s function and promote tumor growth, creating an immunosuppressive environment [ 49 , 50 ]. These properties are typical for alternatively activated M2 macrophages.…”

Mismatch repair gene MSH6 correlates with the prognosis, immune status and immune checkpoint inhibitors response of endometrial cancer

“…It is worth noting that when using CIBERSORT to analyze the relationship between MSH6 and immune cell infiltration, we found that the trend of Tregs infiltration was consistent with CD8 + T cells but opposite to M2 macrophages. Previous studies on the immune microenvironment of various tumor types, such as nasopharyngeal cancer ( 31 ), colorectal cancer ( 32 ), and prostate cancer ( 33 ), have suggested that Tregs are positively correlated with M2 macrophages, and when they highly infiltrate tumor tissue, they usually indicate a poor prognosis. Research by Sun ( 34 ) and Tiemessen ( 35 ) also found that Tregs can promote the differentiation of monocytes into M2 macrophages.…”

Do Elevated YKL-40 Levels Drive the Immunosuppressive Tumor Microenvironment in Colorectal Cancer? Assessment of the Association of the Expression of YKL-40, MMP-8, IL17A, and PD-L1 with Coexisting Type 2 Diabetes, Obesity, and Active Smoking

“…These findings suggest that YKL-40 may play a role in regulating the immune response and promoting tumor growth in colorectal cancer. The different types of immune cells, including M0, M1, M2 macrophages, and Tregs, play a crucial role in regulating the immune response in colorectal cancer [ 62 , 63 , 64 ]. M1 macrophages have a proinflammatory role and can help the immune system to attack cancer cells, while Tregs are known to suppress the immune response.…”