title: Phloroglucinol Inhibits the in vitro Differentiation Potential of CD34 Positive Cells into Endothelial Progenitor Cells.
abstract: Inhibiting the bioactivities of circulating endothelial progenitor cells (EPCs) results in significant inhibition of neovessel formation during tumor angiogenesis. To investigate the potential effect of phloroglucinol as an EPC inhibitor, we performed several in vitro functional assays using CD34(+) cells isolated from human umbilical cord blood (HUCB). Although a high treatment dose of phloroglucinol did not show any cell toxicity, it specifically induced the cell death of EPCs under serum free conditions through apoptosis. In the EPC colony-forming assay (EPC-CFA), we observed a significant decreased in the small EPC-CFUs for the phloroglucinol group, implying that phloroglucinol inhibited the early stage of EPC commitment. In addition, in the in vitro expansion assay using CD34(+) cells, treatment with phloroglucinol was shown to inhibit endothelial lineage commitment, as demonstrated by the decrease in endothelial surface markers of EPCs including CD34(+), CD34(+)/CD133(+), CD34(+)/CD31(+) and CD34(+)/CXCR4(+). This is the first report to demonstrate that phloroglucinol can inhibit the functional bioactivities of EPCs, indicating that phloroglucinol may be used as an EPC inhibitor in the development of biosafe anti-tumor drugs that target tumor angiogenesis.
authors.affiliation: Department of Biomedical Science, Laboratory for Functional Foods & Nutrigenomics, Department of Food Science and Biotechnology, CHA University, Seongnam 463-836.
authors.forename: Yi-Hong
authors.initials: YH
authors.lastname: Kwon
authors.forename: Jun-Hee
authors.initials: JH
authors.lastname: Lee
authors.forename: Seok-Yun
authors.initials: SY
authors.lastname: Jung
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Dong-Hyung
authors.initials: DH
authors.lastname: Lee
authors.forename: Kyu-Sup
authors.initials: KS
authors.lastname: Lee
authors.forename: Boo-Yong
authors.initials: BY
authors.lastname: Lee
authors.forename: Sang-Mo
authors.initials: SM
authors.lastname: Kwon
keywords: Colony forming assay; Endothelial progenitor cell; Phloroglucinol; Tumor angiogenesis