Tumor-Associated Macrophages as Treatment Target in Colorectal Cancer

Abstract

Colorectal cancer (CRC) is one of the common malignant tumors in the digestive tract, and its treatment and prognosis are affected by many factors. Macrophages are cells that participate in innate immunity. Macrophages are cells that participate in innate immunity, maintain the body and resist the invasion of foreign pathogens, and play a supporting role in different organs and tissues. In the tumor microenvironment (TME), macrophages are called tumor-associated macrophages (TAMs), and they play an important role in tumor cell proliferation, metastasis, angiogenesis, and immunosuppression. In this article, we reviewed the interaction between TAMs and tumor cells, discussed the origin and polarization of TAMs, and described the role of TAMs in tumorigenesis and development, invasion and metastasis, and immunosuppression. Finally, we briefly summarized tumor treatment options targeting TAMs to provide new ideas for subsequent tumor research and treatment.

7S,15R-Dihydroxy-16S,17S-epoxy-docosapentaenoic Acid Overcomes Chemoresistance of 5-Fluorouracil by Suppressing the Infiltration of Tumor-Associated Macrophages and Inhibiting the Activation of Cancer Stem Cells in a Colorectal Cancer Xenograft Model

“…Recently, it has been proposed that CSCs can directly or indirectly interact with several immune cell populations within the tumor microenvironment, which are thought to markedly influence tumor progression [ 32 , 33 ]. Therefore, strategies aimed at depleting TAMs carry the promise of increasing chemotherapy efficiency and decreasing anti-cancer drug resistance [ 3 , 9 , 34 ]. In this study, we found that diHEP-DPA significantly inhibited the infiltration of TAMs and decreased the secretion of MMP2, MMP9, VEGF, IL-6, and TNF-α in tumor tissue.…”

“…Similarly, the 5-FU treatment significantly increased the infiltration of TAMs, and produced ornithine decarboxylase-dependent putrescine to confer resistance to further chemotherapy with 5-FU in CRC [ 7 ]. The 5-FU treatment induced the activation of NF-κB and upregulated CSCs in HCT116 high-density tumor microenvironment co-cultures, which were abolished by curcumin [ 34 ]. NF-κB is overactivated in tumors and controls tumor survival, metastasis, and chemoresistance.…”