DNAJ热激蛋白家族B8基因对肺腺癌侵袭转移的作用及其可能的机制

The effect of DNAJ heat shock protein family member B8 gene on lung adenocarcinoma invasion and metastasis and its possible mechanism

目的:探讨DNAJ热激蛋白家族B8基因(DNAJ heat shock protein family member B8,DNAJB8)在肺腺癌组织中的表达及其对肺腺癌细胞侵袭转移的作用和可能机制。方法:收集四川省人民医院2006年至2008年的肺腺癌手术切除标本102例,通过免疫组织化学(IHC)实验检测DNAJB8在肺腺癌组织中的表达情况,并分析其与临床病理参数及预后的关系。构建DNAJB8稳定敲低的肺腺癌A549细胞和DNAJB8稳定过表达的肺腺癌H1299细胞,CCK-8实验检测DNAJB8敲降或过表达对肺腺癌细胞增殖的影响,Transwell法检测其对肺腺癌细胞侵袭能力的影响,Western blotting检测其对肺腺癌细胞内侵袭相关蛋白MMP-2、MMP-9和ERK表达及活性的影响。裸鼠尾静脉注射DNAJB8稳定敲低的A549细胞构建肺腺癌转移模型,观察DNAJB8对A549细胞体内转移能力的影响。结果:DNAJB8在肺腺癌组织中的表达明显高于正常肺组织,其高表达与患者的淋巴结转移及TNM分期呈正相关,并且预示着患者有较差的预后(均P<0.01)。DNAJB8在A549细胞中的表达量高于H1299细胞,下调DNAJB8表达能够抑制A549细胞的侵袭[(41±3)vs(192±11)个,P<0.01],而上调DNAJB8的表达能够促进H1299细胞的侵袭[(235±14)vs(25±4)个,P<0.01]。实验组肺腺癌转移模型裸鼠肺脏肿瘤结节数显著低于对照组[(5±1)vs(17±3)个,P<0.01]。A549细胞中DNAJB8敲降后,MMP-2、MMP-9表达量和p-ERK水平均显著下降(均P<0.01);而H1299细胞高表达DNAJB8后,MMP-2、MMP-9表达量和p-ERK水平均显著升高(均P<0.01)。结论:DNAJB8能够促进肺腺癌的侵袭和转移,其机制可能与MEK/Erk信号通路有关。

Objective： To explore the expression of DNAJB8（Dna J heat shock protein family（Hsp40） member B8）in lung adenocarcinoma tissues and its effect on the invasion and migration of lung adenocarcinoma cells. Methods：102 surgical specimens resected from lung adenocarcinoma surgeries from 2006 to 2008 were collected at Sichuan Provincial People＇s Hospital, the expression of DNAJB8 in lung adenocarcinoma tissues was determined by immunohistochemistry（IHC）, and its relationships with clinical pathological parameters and prognosis were analyzed.A549 cells with stable DNAJB8 knock down and H1299 cells with stable DNAJB8 overexpression were established; the effect of knockdown or overexpression of DNAJB8 on the proliferation of lung adenocarcinoma cells was evaluated by CCK-8 assay, the effect on the invasion ability of lung adenocarcinoma cells was determined using Transwell assay, and the expression of invasion related proteins including MMP-2, MMP-9 and ERK were determined by Western blotting; A xenograft model of lung adenocarcinoma was constructed on nude mice by injecting A549 cells with DNAJB8 knockdown via the tail vein to observe the effect of DNAJB8 on the migration of A549 cells in vivo. Results： The level of DNAJB8 expression in lung adenocarcinoma tissues was significantly higher than that in normal lung tissues, the high expression was positively correlated with lymph node metastasis and TNM staging, and predicted poor prognosis（P〈0.01）. The expression of DNAJB8 in A549 cells was higher than that in H1299 cells, and down-regulation of DNAJB8 expression inhibited the invasion of A549 cells（[41±3] vs [192±11],P〈0.01）, while up-regulation of DNAJB8 promoted the invasion of H1299 cells（[235±14] vs [25±4],P〈0.01）. The number of lung tumors in the mice of experimental group was significantly lower than that in the control group（[5±1] vs [17±3],P〈0.01）. After DNAJB8 knockdown in A549 cells, the expressions of MMP-2, MMP-9 and p-ERK were decreased significantly（P〈0.01）; however, after the overexpression of DNAJB8 in H1299 cells, the expression of MMP-2, MMP-9 and p-ERK were significantly increased（P〈0.01）. Conclusion： DNAJB8 could promote the invasion and metastasis of lung adenocarcinoma cells, which is likely related with the MEK/Erk signaling pathway.