Abstract: Objective To explore the effect of specifically down-regulating glucose-regulated protein 78 on invasion and metastasis capability of adenoid cystic carcinoma. Methods Applying small interfering RNA (siRNA) technology to specifically downregulate the expression of GRP78 and analyzing the difference between ACC-2 and si-GRP78 treated ACC-2 by wound healing, Transwell assay, MTT and cytoskeleton staining. Then we detected the effect of down-regulating GRP78 in ACC-2 on matrix metalloproteinases(MMP)-2,MMP-9,tissue inhibitors of metalloproteinase(TIMP)1 and TIMP-2 by Western blotting technology to compare the ACC-2, control siRNA treated ACC-2 and siGRP78 treated ACC-2. Results Wound healing assay revealed down-regulating GRP78 in ACC-2 could inhibit the wound healing. From Transwell assay, we found that the penetrated cells number decreased significantly by down-regulating GRP78. Cytoskeleton staining showed the fibers of si-GRP78 treated ACC-2 were thickening and distinct obviously, and the fibers of ACC-2 and control siRNA treated ACC-2 were thin and blurred. MTT assay showed that down-regulating GRP78 could inhibit 1/3 reproductive ability of ACC-2. Western blotting manifested that down-regulating the expression of GRP78 in ACC-2 decreased the expression of MMP-2, MMP-9 and increased the expression of TIMP-1, TIMP-2. Conclusion Specific down-regulation of GRP78 could inhibit ACC invasi

Key words: Adenoid cystic carcinoma, Glucose-regulated protein 78, Metastasis, Matrix metalloproteinase, Tissue inhibitors of metalloproteinase, siRNA, Western blotting, Human