Increased frequency and clinical significance of myeloid-derived suppressor cells in human colorectal carcinoma.
OBJECTIVE
To investigate the frequency and clinical significance of the myeloid-derived suppressor cells (MDSC) in human colorectal carcinoma (CRC).


METHODS
Samples of peripheral blood and tumor tissue from 49 CRC patients were analyzed. Mononuclear cells were isolated by Ficoll-Hypaque density gradient centrifugation and were subjected to a flow cytometry-based immunophenotypic analysis.


RESULTS
A considerable increase in the percentage of CD33⁺HLA-DR⁻ MDSCs was observed in the peripheral blood (1.89% ± 0.75%) and tumor tissues (2.99% ± 1.29%) of CRC patients as compared with that in the peripheral blood of healthy controls (0.54% ± 0.35%). This expanded CD33⁺HLA-DR⁻ subset exhibited immature myeloid cell markers, but not lineage markers, and showed up-regulation of CD18/CD11b expression as compared with the MDSCs from healthy donors. Further studies showed that the MDSC proportion in CRC peripheral blood was correlated with nodal metastasis(P = 0.023), whereas that in tumor tissues was correlated with nodal/distant metastasis (P = 0.016/P = 0.047) and tumor stage (P = 0.028), suggesting the involvement of MDSCs in CRC tumor development.


CONCLUSIONS
Characterization of MDSCs in CRC suggests the clinical significance of circulating and tumor-infiltrating MDSCs and may provide new insights into the CRC immunotherapy targeting MDSCs.
Department of Hematology, Wuxi People's Hospital, Wuxi 214023, Jiangsu Province, China.
Hong-Li
HL
Sun
Xin
X
Zhou
Yi-Feng
YF
Xue
Ke
K
Wang
Yun-Feng
YF
Shen
Jing-Jue
JJ
Mao
Hong-Feng
HF
Guo
Zong-Ning
ZN
Miao
D014408:Biomarkers, Tumor / Q000032:analysis; D039481:CD11b Antigen / Q000032:analysis; D018821:CD18 Antigens / Q000032:analysis; D002277:Carcinoma / Q000276:immunology* / Q000556:secondary; D016022:Case-Control Studies; D002469:Cell Separation / Q000379:methods; D002499:Centrifugation, Density Gradient; D016009:Chi-Square Distribution; D002681:China; D015179:Colorectal Neoplasms / Q000276:immunology* / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D016130:Immunophenotyping; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D022423:Myeloid Cells / Q000276:immunology*; D009367:Neoplasm Staging; D010641:Phenotype; D063268:Sialic Acid Binding Ig-like Lectin 3 / Q000032:analysis; D019139:Tumor Escape
D014408:Biomarkers, Tumor; D039481:CD11b Antigen; D018821:CD18 Antigens; C571163:CD33 protein, human; D006684:HLA-DR Antigens; C509295:ITGAM protein, human; D063268:Sialic Acid Binding Ig-like Lectin 3