Differentiation of breast cancer stem cells into vascular endothelial cells and tumor angiogenesis / 西安交通大学学报(医学版)

ABSTRACT

Objective To explore the potential of breast cancer stem cells in differentiating into vascular endothelial cells and participating in the angiogenesis of breast tumor.Methods The expressions of mutant P53, CD31 ,VEGF and Her-2 amplification in tumor blood vessels were detected and the single cell suspension of breast cancer was prepared.CD44+/CD24-/low cells were selected and cultured in culture system.The expressions of CD31 and CD105 on endothelial cell surface were detected by EGM-2 endothelial cell culture medium.The ability of uptake of acetylated low-density lipoprotein was measured.The endothelial cells were cultured in vitro to observe their vascular structure.Results The expressions of CD31,VEGF and mutant P53 were found in paraffin sections of breast cancer tissue samples, and they were arranged along the vessel lumen or blood vessel sphere. Immunofluorescence showed that CD31 and DAPI signals were expressed intravascularly in breast cancer tissues. Four samples of Her-2 positive amplification and 9 cases of non-amplification were detected in the samples.The successful separation of breast cancer stem cells was carried out by immunomagnetic sorting.The percentage of CD44+ cells in the pre-sorting cells was (7.5±2.6)% and that of CD44+ cells was about (94.3±4.7)% after magnetic sorting (P<0.05).The ratio of CD24+ cells was (48.2±9.4)% before sorting,and that of CD24+ cells was (4.3±1.6)% after immunomagnetic bead sorting.The proportion of CD105+ cells in mammary gland cells was (4.5±0.9)% and the proportion of CD31+ cells was (6.2±1.3)%.After cultured for three generations,the percentages of CD105+ cells and CD31+ cells were (79.6±9.3)% and (84.1±10.7)%,respectively (P<0.05). DiL-Ac-LDL could be phagocytized by endothelial cells cultured in endothelial cell culture system.Vessel-like structure was found in the endothelial cell group while the control group did not have the tendency of vascular changes.Conclusion Breast cancer stem cell-derived endothelial cells differentiate into endothelial cells in vitro and have the ability of vascular formation,suggesting that breast cancer stem cells may be involved in the formation of tumor blood vessels.