MMP9 and cancer: Previous studies have indicated that matrix metalloproteinase‐2 (MMP‐2) and matrix metalloproteinase‐9 (MMP‐9) disrupt the extracellular matrix (ECM) and then induce cancer cell migration and invasion.28, 29 In vitro, increased autocrine vascular endothelial growth factor (VEGF) is also considered to be one of the hallmarks of cancer invasion.30 Our results indicated that the combined treatment of 2‐DG and PD led to a significant inhibition of MMP9, MMP2 and VEGF expression compared with the control or individual treatment groups (Figure 2D,E).