Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization

Abstract Background Asymmetric dimethylarginine (ADMA), which is significantly elevated in the plasma of cancer patients, is formed via intracellular recycling of methylated proteins and serves as a precursor for resynthesis of arginine. However, the cause of ADMA elevation in cancers and its impact...

Full description

Bibliographic Details
Main Authors: Yi-Ling Chen, AKaychia T. Lowery, Samuel Lin, Ameae M. Walker, Kuan-Hui E. Chen
Format: Article
Language:English
Published: BMC 2022-11-01
Series:Cancer Cell International
Subjects:
Online Access:https://doi.org/10.1186/s12935-022-02769-7
_version_ 1811217082681917440
author Yi-Ling Chen
AKaychia T. Lowery
Samuel Lin
Ameae M. Walker
Kuan-Hui E. Chen
author_facet Yi-Ling Chen
AKaychia T. Lowery
Samuel Lin
Ameae M. Walker
Kuan-Hui E. Chen
author_sort Yi-Ling Chen
collection DOAJ
description Abstract Background Asymmetric dimethylarginine (ADMA), which is significantly elevated in the plasma of cancer patients, is formed via intracellular recycling of methylated proteins and serves as a precursor for resynthesis of arginine. However, the cause of ADMA elevation in cancers and its impact on the regulation of tumor immunity is not known. Methods Three mouse breast cell lines (normal breast epithelial HC11, breast cancer EMT6 and triple negative breast cancer 4T1) and their equivalent 3D stem cell culture were used to analyze the secretion of ADMA using ELISA and their responses to ADMA. Bone marrow-derived macrophages and/or RAW264.7 cells were used to determine the impact of increased extracellular ADMA on macrophage-tumor interactions. Gene/protein expression was analyzed through RNAseq, qPCR and flow cytometry. Protein functional analyses were conducted via fluorescent imaging (arginine uptake, tumor phagocytosis) and enzymatic assay (arginase activity). Cell viability was measured via MTS assay and/or direct cell counting using Countess III FL system. Results For macrophages, ADMA impaired proliferation and phagocytosis of tumor cells, and even caused death in cultures incubated without arginine. ADMA also led to an unusual macrophage phenotype, with increased expression of arginase, cd163 and cd206 but decreased expression of il10 and dectin-1. In contrast to the severely negative impacts on macrophages, ADMA had relatively minor effects on proliferation and survival of mouse normal epithelial HC11 cells, mouse breast cancer EMT6 and 4T1 cells, but there was increased expression of the mesenchymal markers, vimentin and snail2, and decreased expression of the epithelial marker, mucin-1 in EMT6 cells. When tumor cells were co-cultured ex vivo with tumor antigen in vivo-primed splenocytes, the tumor cells secreted more ADMA and there were alterations in the tumor cell arginine metabolic landscape, including increased expression of genes involved in arginine uptake, metabolism and methylation, and decreased expression of a gene that is responsible for arginine demethylation. Additionally, interferon-gamma, a cytokine involved in immune challenge, increased secretion of ADMA in tumor cells, a process attenuated by an autophagy inhibitor. Conclusion Our results suggest initial immune attack promotes autophagy in tumor cells, which then secrete ADMA to manipulate macrophage polarization favoring tumor tolerance.
first_indexed 2024-04-12T06:49:10Z
format Article
id doaj.art-7828f3ef35584a30b3ac90c51aec647c
institution Directory Open Access Journal
issn 1475-2867
language English
last_indexed 2024-04-12T06:49:10Z
publishDate 2022-11-01
publisher BMC
record_format Article
series Cancer Cell International
spelling doaj.art-7828f3ef35584a30b3ac90c51aec647c2022-12-22T03:43:26ZengBMCCancer Cell International1475-28672022-11-0122111810.1186/s12935-022-02769-7Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarizationYi-Ling Chen0AKaychia T. Lowery1Samuel Lin2Ameae M. Walker3Kuan-Hui E. Chen4Department of Electronic Engineering, National Kaohsiung University of Science and TechnologyDivision of Mathematics and Sciences, Delta State UniversityDivision of Biomedical Sciences, School of Medicine, University of California RiversideDivision of Biomedical Sciences, School of Medicine, University of California RiversideDivision of Mathematics and Sciences, Delta State UniversityAbstract Background Asymmetric dimethylarginine (ADMA), which is significantly elevated in the plasma of cancer patients, is formed via intracellular recycling of methylated proteins and serves as a precursor for resynthesis of arginine. However, the cause of ADMA elevation in cancers and its impact on the regulation of tumor immunity is not known. Methods Three mouse breast cell lines (normal breast epithelial HC11, breast cancer EMT6 and triple negative breast cancer 4T1) and their equivalent 3D stem cell culture were used to analyze the secretion of ADMA using ELISA and their responses to ADMA. Bone marrow-derived macrophages and/or RAW264.7 cells were used to determine the impact of increased extracellular ADMA on macrophage-tumor interactions. Gene/protein expression was analyzed through RNAseq, qPCR and flow cytometry. Protein functional analyses were conducted via fluorescent imaging (arginine uptake, tumor phagocytosis) and enzymatic assay (arginase activity). Cell viability was measured via MTS assay and/or direct cell counting using Countess III FL system. Results For macrophages, ADMA impaired proliferation and phagocytosis of tumor cells, and even caused death in cultures incubated without arginine. ADMA also led to an unusual macrophage phenotype, with increased expression of arginase, cd163 and cd206 but decreased expression of il10 and dectin-1. In contrast to the severely negative impacts on macrophages, ADMA had relatively minor effects on proliferation and survival of mouse normal epithelial HC11 cells, mouse breast cancer EMT6 and 4T1 cells, but there was increased expression of the mesenchymal markers, vimentin and snail2, and decreased expression of the epithelial marker, mucin-1 in EMT6 cells. When tumor cells were co-cultured ex vivo with tumor antigen in vivo-primed splenocytes, the tumor cells secreted more ADMA and there were alterations in the tumor cell arginine metabolic landscape, including increased expression of genes involved in arginine uptake, metabolism and methylation, and decreased expression of a gene that is responsible for arginine demethylation. Additionally, interferon-gamma, a cytokine involved in immune challenge, increased secretion of ADMA in tumor cells, a process attenuated by an autophagy inhibitor. Conclusion Our results suggest initial immune attack promotes autophagy in tumor cells, which then secrete ADMA to manipulate macrophage polarization favoring tumor tolerance.https://doi.org/10.1186/s12935-022-02769-7Arginine metabolismAsymmetric dimethylargininecancer stem cellsAutophagyMacrophage polarization
spellingShingle Yi-Ling Chen
AKaychia T. Lowery
Samuel Lin
Ameae M. Walker
Kuan-Hui E. Chen
Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization
Cancer Cell International
Arginine metabolism
Asymmetric dimethylarginine
cancer stem cells
Autophagy
Macrophage polarization
title Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization
title_full Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization
title_fullStr Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization
title_full_unstemmed Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization
title_short Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization
title_sort tumor cell derived asymmetric dimethylarginine regulates macrophage functions and polarization
topic Arginine metabolism
Asymmetric dimethylarginine
cancer stem cells
Autophagy
Macrophage polarization
url https://doi.org/10.1186/s12935-022-02769-7
work_keys_str_mv AT yilingchen tumorcellderivedasymmetricdimethylarginineregulatesmacrophagefunctionsandpolarization
AT akaychiatlowery tumorcellderivedasymmetricdimethylarginineregulatesmacrophagefunctionsandpolarization
AT samuellin tumorcellderivedasymmetricdimethylarginineregulatesmacrophagefunctionsandpolarization
AT ameaemwalker tumorcellderivedasymmetricdimethylarginineregulatesmacrophagefunctionsandpolarization
AT kuanhuiechen tumorcellderivedasymmetricdimethylarginineregulatesmacrophagefunctionsandpolarization