BDNF,TrkB在原发性肝癌中的表达及BDNF对肝癌细胞株Bel-7402的作用

The expression of BDNF and TrkB in primary liver cancer and the effects of BDNF on liver cancer cell line Bel-7402

目的探讨脑源性神经营养因子(BDNF)及其受体TrkB在原发性肝癌中的表达及BDNF对肝癌细胞株Bel-7402的作用。方法 (1)检测肝癌组织、癌旁组织及正常肝组织中BDNF和TrkB的表达,分析BDNF和TrkB的表达与临床病理因素之间的关系。(2)检测BDNF,TrkB,Bcl-2在肝癌细胞株Bel-7402及正常肝细胞株L-02的表达及其对Bel-7402细胞增殖、失巢凋亡、黏附、浸润转移能力的影响。结果 (1)肝癌组织中BDNF呈高表达(60.4%,29/48),与Edmondson分级、有无包膜有关(P<0.05);TrkB表达率为52.1%(25/48),与Edmondson分级及肿瘤结节数有关(P<0.05);BDNF与TrkB在肝癌中的表达呈正相关(r=0.332,P<0.05)。BDNF和TrkB在正常肝组织中均无表达。两者在肝癌组织中表达远高于癌旁组织中的表达(P<0.01)。肝癌组织中BDNF和TrkB呈高表达者,其2年内复发率增高(P<0.05)及生存率下降(P<0.01)。(2)外源性BDNF均能增强Bel-7402细胞的增殖、黏附、体外迁移、侵袭能力及抵抗失巢凋亡的能力(P<0.01);(3)各浓度的BDNF均可上调Bel-7402细胞Bcl-2 mRNA及其蛋白的表达(P<0.05)。结论 (1)BDNF及TrkB在肝癌中高表达,可能与复发、生存率有关;(2)BDNF可调节肝癌细胞的生长、黏附、迁移和侵袭;(3)BDNF可上调Bcl-2的表达,抑制肿瘤细胞的失巢凋亡。

Objective To explore the expression of brain-derived neurotrophic factor（BDNF） and its receptor（TrkB） protein in primary liver cancer and the effects of exogenous BDNF on biological behavior of liver cancer Bel-7402 cell line.Methods（1）The expression of BDNF and TrkB was detected by immunohistochemistry in 8 cases of normal liver tissue,48 cases of liver cancer（LC） and their respective surrounding tissue to analyze the relationships between BDNF,TrkB expression and the clinicopathological features,recurrence and survival rate in liver cancer;（2） cell proliferation,anoikis rate,adhesion,invasion and mobility ability as well as expression level of mRNA and protein of BDNF,TrkB,Bcl-2 in liver cancer cell line Bel-7402 and normal liver cell line L-02 were investigated.Results（1）Normal liver tissues showed negative expression for BDNF and TrkB protein,however,in liver cancer,the positive rate of BDNF and TrkB protein was 69.0%（29/48） and 52.1%（25/48）,respectively,which was higher than those in their surrounding tissues（P〈0.05）.BDNF and TrkB positive rate had significant relations with Edmondson Grade,capsule formation and multiple nodules of tumor respectiverly（P〈0.05）.There was positive correlation of expressin BDNF and TrkB（r=0.332,P〈0.05）.High expression of BDNF and TrkB in LC significantly increased two year′s recurrence rate（P〈0.05） and decreased survival time（P〈0.01）;（2）MTT and adhesion assay showed that BDNF can promote cell proliferation and ability of adhesion（P〈0.01）;（3） Flow cytometry showed that BDNF can enhance the ability to resist anoikis（P〈0.01）;（4） Transwell chamber assay and scrape migration assay showed that BDNF can enhance the ability of invasion and mobility of Bel-7402 in nonconcentration-dependent manner（P〈0.01）;（5）RT-PCR and Western Blot showed that BDNF can up-regulate the expression of mRNA and protein of Bcl-2 in Bel-7402 cells,respectively（P〈0.05）.Conclusions （1） BDNF and TrkB protein are highly expressed in liver cancer and may be related to recurrence and survival time;（2） BDNF can modulate cell proliferation,adhesion,mobility and invasion in liver cancer Bel-7402 cell line;（3） BDNF can up-regulate the expression of Bcl-2 to inhibit the anoikis of Bel-7402 cell line.