The invasion and metastasis is a complex process that is
regulated by many signaling molecules [20]. Among them,
matrix metalloproteinases (MMPs), especially MMP-2 and
MMP-9, have been demonstrated to play important roles in
this process by degrading the extracellular matrix [21, 22].We
previously reported that overexpression of GRP78 promoted
the invasion and metastasis of HCC and knockdown of
GRP78 reduced the activity of MMPs [23, 24]. However, the
role of cell surface GRP78 in the regulation of MMPs is still
unknown.