石蜡包埋人胰腺癌组织中Smad4蛋白和转化生长因子β1及其Ⅱ型受体的表达

目的：探讨转化生长因子（TGF）－β通路中Smad4蛋白,TGFβ1和转化生长因子βⅡ型受体（TβRⅡ）的关系及它们在胰腺癌中的可能作用机制。方法：用EnVision免疫组织化学技术检测56份石蜡包埋人胰腺癌标本Smad4蛋白,TGFβ1和TβRⅡ蛋白表达的情况。结果：56份胰腺癌组织Smad4,TGFβ1和TβRII阳性率分别为58．93％（33）,66．07％（37）和60．71（34）,对应正常胰腺组织阳性率分别为89．29％（50）,25．00％（14）和25．00％（14）,TGFβ1的表达与临床分期,肿瘤的有无转移相关（P＜0．05）,TGFβ1和TβRII之间也有相关关系（P＜0．05）,结论：胰腺癌组织中Smad4表达降低,TGFβ1与TβRII则呈过表达,TGFβ1和TβRII对胰腺癌的发生可能有协同作用。Smad在TGF－β诱导基因表达调控和随后的生长抑制中是关键的转录因子,但TGFβ有时也可能以与Smad4无关的形式起作用。

Detection of the expression of Smad4, transforming growth factor beta(1) and beta receptor II proteins in paraffin-embedded human pancreatic cancer tissues

OBJECTIVE: To explore the relationships between Smad4, TGF beta1 and TbetaR II in the TGF-beta pathway and the possible mechanisms by which they effect pancreatic carcinoma. METHODS: The expression of Smad4, TGF beta1 and TbetaR II in paraffin embedded pancreatic carcinoma tissues was detected by using antibodies against Smad4, TGF beta1 and TbetaR II with EnVision immunohistochemistry. RESULTS: The positive rates of Smad4, TGF beta1 and TbetaR II were 58.93% (33), 66.07% (37) and 60.71% (34), respectively. The positive rates of the above three proteins in matched normal pancreatic tissues were 89.29% (50), 25.00% (14) and 25.00% (14) respectively. There was a significant relationship between the expression of TGF beta1, clinical stage and the metastasis of the tumor (P < 0.05). There was also a significant relationship between the expressions of TGF beta1 and TbetaR II (P < 0.05). CONCLUSIONS: The expression of Smad4 in pancreatic carcinoma tissue is significantly decreased but the expression of TGF beta1 and TbetaR II are increased. Smad4 may play an important role in the regulation of TGFbeta inducible gene expression and subsequent growth inhibition, but TGFbeta may also act in a Smad4-independent manner.