[The effect of GDNF on matrix-degrading and cell-adhesion during perineural invasion of salivary adenoid cystic carcinoma].

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-kappaB,integrin beta1 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-kappaB, MMP-9, integrin beta1 were positively expressed in ACC cell cytoplasm, integrin beta1 was also found in ACC cell membrane, and NF-kappaB 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-kappaB, MMP-9, integrinbeta1 in PNI group and non-PNI group were significant (P=0.005,P=0.011,P=0.001, respectively). Expression of NF-kappaB, MMP-9, integrin beta1 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 beta1 was positively correlated to that of NF-kappaB(r=0.501, P=0.001; r=0.429, P=0.005). Expression of MMP-9 was correlated positively to that of integrin beta1 (r=0.381, P=0.013). CONCLUSIONS：GDNF may increase the matrix-degrading and cell-adhesion of ACC in the process of PNI. NF-kappaB, MMP-9 and integrin beta1 involve in ACC cells invading nerves.