Enhanced adhesion of early endothelial progenitor cells to radiation-induced senescence-like vascular endothelial cells in vitro.
The effects of ionizing radiation (IR) on tumor neovascularization are still unclear. We previously reported that vascular endothelial cells (ECs) expressing the IR-induced senescence-like (IRSL) phenotype exhibit a significant decrease in angiogenic activity in vitro. In this study, we examined the effects of the IRSL phenotype on adhesion to early endothelial progenitor cells (early EPCs). Adhesion of human peripheral blood-derived early EPCs to human umbilical vein endothelial cells (HUVECs) expressing the IRSL phenotype was evaluated by an adhesion assay under static conditions. It was revealed that the IRSL HUVECs supported significantly more adhesion of early EPCs than normal HUVECs. Expressions of ICAM-1, VCAM-1 and E-selectin were up-regulated in IRSL HUVECs. Pre-treatment of IRSL HUVECs with adhesion-blocking monoclonal antibodies against E-selectin and VCAM-1 significantly reduced early EPC adhesion to IRSL HUVECs, suggesting a potential role for the E-selectin and VCAM-1 in the adhesion between IRSL ECs and early EPCs. Therefore, the IRSL phenotype expressed in ECs may enhance neovascularization via increased homing of early EPCs. Our findings are first to implicate the complex effects of this phenotype on tumor neovascularization following irradiation.
Sermsathanasawadi
Nuttawut
N
Department of Vascular and Applied Surgery, Tokyo Medical and Dental University, Tokyo, Japan.
Ishii
Hideto
H
Igarashi
Kaori
K
Miura
Masahiko
M
Yoshida
Masayuki
M
Inoue
Yoshinori
Y
Iwai
Takehisa
T
D002448:Cell Adhesion / Q000528:radiation effects*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000528:radiation effects*; D042783:Endothelial Cells / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology* / Q000528:radiation effects
D015815:Cell Adhesion Molecules