Cannabinoid Receptor-1 suppresses M2 macrophage polarization in colorectal cancer by downregulating EGFR

Abstract

Cannabinoid receptors, CB1 and CB2, have been implicated as emerging targets for cancer therapy. Herein, we investigated the potential regulation mechanism of CB1 and its implications in colorectal cancer. CB1 and EGFR expression were examined in colorectal cancer cell lines. The effects of CB1 agonist ACEA and its antagonist AM251 on the proliferation, migration and invasion of colorectal cancer cells and the expression of M1 and M2 macrophage markers were examined. EGFR overexpression was performed with plasmids containing EGFR gene. Tumor xenografts were constructed to explore the effects of CB1 activation on tumorigenesis. We showed that CB1 was downregulated while EGFR was upregulated in colorectal cancer cells. The activation of CB1 suppressed the proliferation, migration and invasion of colorectal cancer cells and the differentiation of M2 macrophages, while CB1 inhibition had opposite effects. Moreover, the alterations in tumorigenesis and M2 macrophage activation induced by CB1 activation were counteracted by EGFR overexpression. Besides, CB1 silencing promoted tumor cell proliferation and M2 polarization which was counteracted by EGFR knockdown. In vivo, CB1 activation also repressed tumorigenesis and M2 macrophage activation. The present study demonstrated that CB1 activation suppressed M2 macrophage through EGFR downregulation in colorectal cancers. These findings first unveiled the potential avenue of CB1 as a targeted therapy for colorectal cancer.

Combination Curcuma longa and Phyllanthus niruri Extract Potentiate Antiproliferative in Triple Negative Breast Cancer MDAMB-231 Cells

“…Another study revealed that EGFR silencing inhibits TNBC cell proliferation and increase apoptosis through the suppression of STAT3 (Song et al, 2020b). Nude mouse tumor formation assays verified that EGFR silencing could suppress tumor cell growth (Song et al, 2020b;Deng et al, 2022).…”

Cannabinoids’ Role in Modulating Central and Peripheral Immunity in Neurodegenerative Diseases

“…CB1Rs are immunomodulators in macrophages [ 51 , 53 ], T cells [ 52 , 54 ], neutrophils [ 55 ], mast cells [ 56 ], and dendritic cells [ 57 ].…”

“…CB2Rs regulate cytokines and ROS production, cell proliferation, apoptosis, and phagocytosis [ 17 , 53 , 54 , 90 , 92 , 93 , 94 ]. These effects occur via signal transduction pathways such as adenylyl cyclase inhibition, p38 and ERK1/2 activation, and nuclear factor kappa B (NF-κB) [ 17 , 70 , 94 ].…”

Phytochemicals as Immunomodulatory Molecules in Cancer Therapeutics

“…IL-4, IL-13, CD206, Fizz1, and PPARγ protein levels are blocked by fenretinide, which finally inhibits M2 polarization without any effect on M1 polarization. Cannabinoids can modulate macrophage activity by reducing the expression of TNFα and IL-1β, suggesting its anticancer potential in xenograft tumors for colorectal cancer cells (HTC116, SW480, SW620, and HT29) [162,180]. Echinacea, on the other hand, enhances cytokine production (TNF-α, IL-1, IFN-β), activates macrophages by increasing the expression of CD80, CD86, MHCII molecules, and phagocytosis in murine bone marrow-derived macrophages [165,181].…”