Abstract: PURPOSE: To investigate the possible contribution of GDNF in matrix-degrading, cell-adhesion during perineural invasion (PNI) of salivary adenoid cystic carcinoma (ACC). METHODS: Totally 42 ACCs and 5 normal salivary tissues were included in the present study.Immunohistochemical staining SP method was used to detect the expression of GDNF,MMP-9,NF-κB,integrin β1 in ACC specimens and normal salivary tissues. Statistical analysis was performed using SPSS16.0 software package. RESULTS:GDNF was strongly expressed in ACC tumor cells and nerve fibers adjacent to ACC tumor cells. NF-κB, MMP-9, integrin β1 were positively expressed in ACC cell cytoplasm, integrin β1 was also found in ACC cell membrane, and NF-κB in nuclei occasionally. The positive expression rate was 69.05%(29/42),66.67%(28/42),61.90%(26/42), respectively. The differences between the expression of NF-κB, MMP-9, integrinβ1 in PNI group and non-PNI group were significant (P=0.005,P=0.011,P=0.001, respectively). Expression of NF-κB, MMP-9, integrin β1 was correlated to that of GDNF(r=0.443, P=0.003; r=0.401, P=0.009; r=0.535, P=0.000, respectively). Expression of MMP-9 and integrin β1 was positively correlated to that of NF-κB(r=0.501, P=0.001; r=0.429, P=0.005). Expression of MMP-9 was correlated positively to that of integrin β1 (r=0.381, P=0.013). CONCLUSIONS:GDNF may increase the matrix-degrading and cell-adhesion of ACC in the process of PNI. NF-κB, MMP-9 and integrin β1 involve in ACC cells invading nerves.

Key words: Adenoid cystic carcinoma, MMP-9, NF-κB, Glial cell line-derived neurotrphic growth factor, Perineural invasion, Integrin β1