Toll样受体-4与胰腺癌侵袭和转移的关系

Correlation of TLR4 expression with invasion and metastasis of pancreatic cancer

背景与目的:Toll样受体-4(Toll-like receptor-4,TLR4)与多种肿瘤的侵袭和转移密切相关,然而其机制尚未阐明。本研究旨在探讨TLR4与胰腺癌侵袭和转移的关系,并分析其相关机制。方法:采用免疫组化法检测59例胰腺癌手术切除标本及30例癌旁正常胰腺组织中TLR4、基质金属蛋白酶-9蛋白(matrixmetalloproteinase-9,MMP-9)表达,分析TLR4、MMP-9蛋白表达与胰腺癌主要临床病理参数以及TLR4、MMP-9之间的相关性。以脂多糖(lipopolysaccharide,LPS)作用于体外培养的人胰腺癌细胞株PANC-1,通过Transwell小室检测细胞侵袭力,蛋白质印迹法(Western blot)检测MMP-9蛋白表达。结果:胰腺癌组织TLR4、MMP-9蛋白阳性表达率分别为72.9%和69.5%,均显著高于正常胰腺组织(P<0.01)。TLR4蛋白表达与肿瘤的TNM分期、淋巴结转移密切相关,MMP-9蛋白与肿瘤的分化程度、淋巴结转移及TNM分期密切相关(P<0.05)。Spearman等级相关分析表明,TLR4表达与MMP-9表达呈显著正相关(P<0.01)。经LPS作用后,PANC-1细胞的侵袭数目较正常组显著增加(P<0.01)。经LPS作用6、12和24 h后,PANC-1细胞MMP-9蛋白的相对表达量均显著高于正常组(P<0.01)。结论:TLR4蛋白表达与胰腺癌的侵袭和转移密切相关,其机制可能与促进MMP-9蛋白表达有关。

Background and purpose： Studies have shown that Toll-like receptor-4 （TLR4） is associated with invasion and metastasis of various tumor types. However, its mechanism has not been elucidated and its relation- ship with pancreatic cancer needs further study. This study was aimed to investigate the correlation of TLR4 expression with invasion and metastasis of pancreatic cancer, and to analyze the underlying mechanism. Methods： Fifty-nine resected human pancreatic adenocarcinoma specimens and 30 para-carcinoma normal pancreatic tissues were used to detect the TLR4 and matrix metalloproteinase-9 （MMP-9） protein expression by immunohistochemical methods. The correlations among TLR4 protein expression, MMP-9 protein expression and clinicopathologic feature of the patients were analyzed. After stimulated with lipopolysaccharide （LPS）, MMP-9 protein expression of human pancreatic cancer cell lines PNAC-1 was examined by Western blot and the invasion ability of pancreatic cancer cells was evaluated by Transwell invasion chamber assay. Results： TLR4 and MMP-9 protein positive expression rates in pancreatic adenocarcinoma were 72.9% and 69.5% respectively, which were significantly higher than those in normal pancreatic tissue （P〈0.01）. TLR4 protein expression was closely related to TNM stage, lymph node metastasis and MMP- 9 protein expression was significantly correlated with tumor differentiation, TNM stage and lymph node metastasis （P〈0.05）. The Spearman rank correlation test showed that there was a strong correlation between TLR4 and MMP-9 protein expression （P〈0.01）. Compared with the normal group, the invasive cells number of PANC-1 was significantly increased after stimulated with LPS （P〈0.01）. After stimulated with LPS for 6, 12 and 24 h, MMP-9 protein relative expressions in PANC-1 cells were significantly higher than those in the normal group （P〈0.01）. Conclusion： TLR4 protein expression is closely related to invasion and metastasis of pancreatic cancer, and its mechanism is related to promoting MMP-9 protein expression.