BDNF/TrkB在唾液腺腺样囊性癌上皮-间质转化过程中的表达及意义

目的 研究BDNF、TrkB和E-cadherin在唾液腺腺样囊性癌（SACC）细胞系中的表达,初步探讨BDNF、TrkB和E-cadherin与SACC高转移性及神经侵袭性之间的关系。方法 以SACC高、低转移细胞系SACC-LM和SACC-83为研究对象,利用实时荧光定量 PCR和Western 免疫印迹技术检测BDNF、TrkB和E-cadherin在其中的表达差异;在SACC-83细胞系中加入外源性BDNF因子、TrkB抑制剂k252a,分析BDNF/TrkB通路在SACC侵袭转移过程中的生物学作用;利用实时荧光定量 PCR、Western 免疫印迹、细胞形态观察、细胞迁徙和侵袭实验评估SACC细胞上皮-间质转化（EMT）进程。应用SPSS17.0软件包对数据进行统计学处理。结果 BDNF 和TrkB在SACC-LM中的表达高于SACC- 83,E-cadherin在SACC-LM中的表达低于SACC- 83;外源性BDNF刺激能有效诱导TrkB的激活和表达,降低E-cadherin的表达,提高N-cadherin的表达,使细胞形态呈长梭形改变,促进SACC-83细胞的迁徙、侵袭能力;而TrkB受体抑制剂k252a可有效抑制BDNF的各种作用,降低SACC-83细胞形态变化和迁徙、侵袭能力。结论 BDNF/TrkB信号通路通过介导SACC的EMT过程,促进SACC的迁徙、侵袭能力。

Expression of BDNF/TrkB in the progress of epithelial-mesenchymal transition in salivary adenoid cystic carcinoma

PURPOSE: To investigate the expression of BDNF,TrkB and E-cadherin in salivary adenoid cystic carcinoma (SACC) and study their role in metastasis and nerve invasion. METHODS: The high and low metastatic SACC cell lines (SACC-LM, SACC-83) were analyzed by real-time PCR and Western blot to determine the expression of BDNF, TrkB and E-cadherin. To observe the BDNF/TrkB pathway in the metastasis process of SACC, the SACC-83 cells were treated by exogenous BDNF and/or TrkB inhibitor k252a, respectively. Meanwhile, the epithelial mesenchymal transition (EMT) of SACC-83 cells were evaluated by real-time PCR, Western blot, morphology observation, cell migration and invasion analysis. SPSS 17.0 software package was employed to analyze the data statistically. RESULTS: The expression of BDNF and TrkB in SACC-LM cells were higher than SACC-83 cells whereas the E-cadherin was down regulated. Exogenous BDNF could activate TrkB, inhibit E-cadherin and promote N-cadherin expression in SACC-83 cells. The morphology of SACC-83 cells stimulated by BDNF was also elongated and migration and invasion capabilities were improved. When TrkB was inhibited by k252a, the BDNF effects were inhibited including the suppressing of SACC-83 morphology alteration, migration and invasion capabilities. CONCLUSIONS: BDNF/TrkB pathway can promote the migration and invasion capabilities of SACC cells by mediating its EMT progression.