OBJECTIVETo investigate the relation of vascular endothelial growth factor receptor 1 (VEGFR1)-positive hematopoietic progenitor cell with the metastasis of human colorectal carcinoma.

METHODSHuman colorectal cancer cells SW480/M5 were implanted into BALB/c nude mice, and the tumor tissue blocks were re-implanted into the colon of nude mice. The quantity and percentage of VEGFR1-positive hematopoietic progenitor cells and human colorectal cancer cells in the pre-metastatic location were observed with flow cytometry, and the expression of metastasis-related factors was detected using Western blotting.

RESULTSBone marrow-derived hematopoietic progenitor cells expressing VEGFR1 were found in the common pre-metastatic sites and formed cell clusters before the arrival of the tumor cells, but these cells were not detected in nude mice without tumor implantation. In the course of tumor metastasis, the expression of the proteinases including matrix metalloproteinase 9 and stromal cell-derived factor 1 gradually intensified within the metastatic niche.

CONCLUSIONThe formation of VEGFR1-positive hematopoietic progenitor cellular clusters is accompanied by the metastasis of human colorectal cancer, and may enhance the expression of metastasis-related factors, suggesting its important role in the invasion and metastasis of colorectal cancer.