Objective      To determine the biological behavior and angiogenesis of residual hepatoma cells filtered by insufficient ablation of high intensity focused ultrasound (HIFU).       Methods      The relationship of temperature-time of HIFU irradiation to hepatoma SMMC7721 cells was firstly identified under a sound power of 5 W. Based on the determined temperature

a subline of SMMC7721 cells that can survive from HIFU treatment was screened under HIFU irradiation and then established and expanded. The proliferative rate and heat tolerance of the obtained cell subline was tested by CKK-8 assay

cell migration and invasion was measured by cell scratch assay and transwell chamber assay.       Results      With the time elapse of HIFU irradiation

the temperature was increased and the mortality was increased gradually. All SMMC7721 cells died at 48 ℃. The best cell subline generated at 47 ℃ had higher proliferation rate and stronger heat tolerance than control hepatoma cells (P0.05)

but had no significant alteration in movement and infiltration capacities

and could promot the proliferation

migration and lumen formation in human umbilical vein endothelial cells (P0.05).       Conclusion      HIFU radiation can kill hepatoma cells

however

insufficient HIFU ablation results in transformation of some survival cells and promotion of angiogenesis.