特异性阻断Hedgehog信号通路对胰腺癌细胞凋亡的影响及分子机制

The effect and mechanism of blocking the hedgehog signaling pathway on apoptosis in pancreaticcancer Mia PaCa-2 cells

目的观察特异性阻断Hedgehog信号通路对人胰腺癌MiaPaCa-2细胞凋亡的影响，探讨其可能的分子机制。方法应用特异性Hedgehog通路阻断剂KAAD—cyclopamine阻断MiaPaCa-2细胞的Hedgehog信号通路，噻唑蓝（MTF）法检测阻断Hedgehog信号通路对胰腺癌细胞生长情况的影响；流式细胞技术观察细胞凋亡的变化；Westernblot方法检测bax和bel-2表达的变化。结果KAAD．eyelopamine明显抑制胰腺癌MiaPaCa-2细胞生长，其作用呈剂量依赖性；阻断Hedgehog信号通路后，胰腺癌细胞凋亡显著增加，细胞中bax表达水平上调，bcl-2表达水平明显下调。结论特异性阻断Hedgehog信号通路使胰腺癌细胞生长抑制，凋亡明显增加，其机制可能为通过上调bax及下调bcl-2的表达水平实现。

Objective To study the effect of blocking the hedgehog signaling pathway on apoptosis in pancreatic cancer Mia PaCa-2 ceils and its possible mechanism. Methods The Mia PaCa-2 ceils were treated with KAAD-cyclopamine at various concentrations for 48 h. Growth suppression was evaluated by MTT method. Flow cytometry （FCM） was used to assay the apoptotic rate. Western blot was used to detect the protein expression of bcl-2 and bax. Results A dose-dependent inhibitory effect of KAAD-cy- clopamine on MiaPaCa-2 pancreatic caner cells was observed by MTT method. The result of FCM indica- ted that cancer ceils treated with KAAD-cyclopamine for 48 h exhibited a significant increase of apoptosis, the expression of bcl-2 was significantly down-regulated and that of bax up-regulated. Conclusion KAAD-cyclopamine inhibits the proliferation of Mia PaCa-2 cells. Apoptostic induction may be the main antineoplastic mechanism, which is mediated by altering apoptosis-related genes through down-regulation of bcl-2 and up-regulation of bax proteins.