Abstract: 【Abstract】 Objective To investigate the effect of the key glycolysis enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 （PFKFB3） on the biological activity of hemangioma-derived endothelial cells （HemECs）. Methods Totally, 4 proliferating infantile hemangioma （IH） tissues and 4 involuting IH tissues were collected. Primary HemECs were isolated from the proliferating IH tissues, and human umbilical vein endothelial cells （HUVECs） served as controls. Immunohistochemical study and Western blot analysis were performed to determine the expression of PFKFB3 in the IH tissues and HemECs, respectively. Cell counting kit-8 （CCK8） assay was conducted to evaluate the effect of PFK15 （a specific inhibitor of PFKFB3） at concentrations of 0 - 10 μmol/L on the proliferation of HemECs, and HemECs treated without PFKFB3 served as the control group. Some in vitro cultured HemECs were treated with 5 μmol/L PFK15, and served as a PFK15 intervention group, while HemECs treated without PFK15 served as a control group; then, the migratory ability of HemECs was assessed by Transwell assay, and the apoptosis level of HemECs was detected by flow cytometry. Comparisons between groups were performed by using t test or analysis of variance. Results Immunohistochemical study showed that the positive rate of PFKFB3 was significantly higher in the proliferating IH tissues （74.34% ± 5.26%） than in the involuting IH tissues （41.46% ± 2.99%, t = 9.40, P < 0.001）. Western blot analysis showed that the relative expression level of PFKFB3 was also significantly higher in HemECs （0.73 ± 0.05） than in HUVECs （0.45 ± 0.04, t = 8.50, P < 0.001）. CCK8 assay revealed significantly decreased proliferative activity of HemECs in the 0.625-, 1.25-, 2.5-, 5-, and 10-μmol/L PFK15 groups compared with the control group （all P < 0.01）. Compared with the control group, the PFK15 intervention group showed significantly decreased number of migratory HemECs （297 ± 15 vs. 422 ± 8, t = 12.59, P < 0.001）, but significantly increased apoptosis rates of HemECs （6.69% ± 0.64% vs. 0.34% ± 0.07%, t = 17.07, P < 0.001）. Conclusion The key glycolytic enzyme PFKFB3 was highly expressed in the proliferating IH tissues and HemECs, and the PFKFB3 inhibitor PFK15 could suppress the proliferation, migration, and increase the apoptosis of HemECs.

Key words: Hemangioma, Hemangioma-derived endothelial cell, Glycolysis, Cell proliferation, Apoptosis, Cell migration, 6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 3