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Updated: Oct 21, 2025
Colorectal Cancer Cell Surface Protein Profiling Using an Antibody Microarray and Fluorescence Multiplexing
Published on: September 25, 2011
The myeloid cell biomarker EMR1 is ectopically expressed in colon cancer
Haytham Ali1,2,3, Lina Olsson1, Gudrun Lindmark4
1Department of Clinical Microbiology, Infection and Immunology, Umeå University, SE-90185, Umeå, Sweden.
Objective:
The microenvironment of colon cancer (CC) is heterogeneous including cells of myeloid lineage affecting tumor growth and metastasis. Two functional subtypes of myeloid cells have been identified; one (M1) is tumor-inhibitory and the other one (M2) is tumor-promoting. Whether the three myeloid markers EMR1, CD206 and CD86 are expressed only in the infiltrating myeloid cells or also in the tumor cells was investigated.
Methods:
Expression of the myeloid markers was investigated in CC at the mRNA and protein levels in primary tumors and lymph nodes. mRNA expression was also determined in 5 CC cell lines. Protein expression was investigated by two-color immunofluorescence and consecutive-sections-immune-staining combined with morphometry using specific antibodies for the myeloid cell markers and the epithelial cell markers CEACAM5 and EpCAM.
Results:
EMR1 and CD86, but not CD206, mRNA levels were significantly higher in CC primary tumors compared to apparently normal colon tissue (P < 0.0001). EMR1 mRNA levels were significantly higher in both hematoxylin-eosin positive (H&E(+)) and H&E(-) lymph nodes of CC patients compared to control nodes (P = 0.03 and P = 0.01, respectively). EMR1 and CD206 mRNAs were expressed in 4/5 and 5/5 CC cell lines, respectively, while CD86 mRNA was not expressed. Immuno-morphometry revealed that about 20% of the tumor cells expressed EMR1 and CD206. Positive cells were tumor cells as revealed by anti-CEACAM5 and anti-EpCAM staining. The number of EMR1, CD206 and CD86 positive cells were significantly increased in CC primary tumors compared to normal colon tissue (P < 0.0001). However, CD206 was also expressed in normal colonocytes. Only EMR1 showed significantly increased numbers of positive tumor cells in H&E(+) nodes compared to H&E(-) nodes (P = 0.001). EMR1 expression in CC tumor cells correlated with CXCL17 expressing tumor cells.
Conclusion:
EMR1, like the chemokine CXCL17, is ectopically expressed in colon cancer possibly in the same cancer cells.
