Hedgehog信号传导通路相关基因在肝癌组织中的表达研究

Hedgehog signaling pathway activation in hepatocellular carcinoma

目的研究Hedgehog信号传导通路相关基因在肝癌组织中的表达，及其抑制剂对肿瘤细胞生长的影响。方法免疫组化法检测14例肝癌组织切片、4个肝癌细胞系和正常肝细胞中Hedgehog信号传导通路成员Ihh、Ptch、Smo、Gli的蛋白表达；Western blot检测9例新鲜肝癌组织标本、6例正常肝组织标本和肝癌细胞系中Ihh、Ptch、Smo、Gli的蛋白表达；RT—PCR检测3肝癌组织标本和肝癌细胞系中Ihh、Ptch、Smo、Gli、HipmRNA表达。结果14例肝癌组织中免疫组化染色阳性的Gli 6例（42．9％），Ptch 10例（71．4％），Ihh 10例（71．4％），Smo 12例（85．7％）。Western blot和RT-PCR检测显示，肿瘤组织中Gli基因的mRNA和蛋白表达均高于正常肝脏细胞，Hip基因的mRNA表达低于正常肝细胞。肝癌细胞系HepG2，Bel-7402和QGY-7701免疫细胞化学染色Ptch和G1i同时为阳性，证明为Hedgehog通路活化的细胞系。在环耙明（KAAD-cyclopamine）作用后，3个细胞系Ptch及Gli基因的mRNA表达下调（Ptch基因tHepG2=3．78，tBel-7402=9．03，tQGY-7701=5．63，G1i基因tHepC2=9．61，tBel-7402=4．15，tQGY-7701=20．30，均P〈0．05）；QGY-7701组Hip基因RNA表达上调（t=4．70，P〈0．05）。环耙明抑制肝癌细胞系QGY-7701的作用最明显。结论原发性肝癌组织中Hedgehog信号传导通路有多种基因表达，环耙明有抑制肝癌细胞生长的作用。

Objective To investigate the expressions of Hedgehog signaling pathway genes in hepatocellular carcinoma tissues （ HCC ） , and the effect of specific Hedgehog pathway inhibitor （ KAAD cyclopamine） on the growth of HCC cells and the expressions of Hedgehog genes. Methods The expression of Hedgehog signaling pathway components （Ihh, Ptch, Smo and Gli） was investigated in 14 HCC tissue slices, 4 HCC cell lines and a normal hepatic cell line by using immunochemistry. The expression of Ihh, Ptch, Smo and Gli proteins was investigated in 9 HCC tissue specimens and 6 normal hepatic tissue specimens by using Western blotting. The expression of lhh,Ptch,Smo,Gli and Hip genes was investigated by RT-PCR, Results The positive ratio of Gli, Ptch, Ihh and Smo were 42.9%, 71.4%, 71.4% and 85.7% in 14 HCC tissue slices, respectively. The expressions of Gli protein and Gli gene were up regulated while the expression of Hip gene was down regulated in HCC specimens compared with normal hepatic tissue specimens. Hedgehog signaling pathways in HCC cell lines HepG2, Bel-7402 and QGY-7701 were activated ; KAAD-cyclopamine, a specific inhibitor of the Hedgehog signaling pathway, down regulated cell growth and the expressions of Ptch and Gli genes in the 3 HCC cell lines（ Ptch gene： tHepG2 = 3. 78, tBel-7402 =9. 03, tQGY-7701 =5.63 ; Gli gene： tHepG2 =9. 61, tBel-7402 =4. 15, tQGY-7701 =20. 30, P 〈0. 05 in each group）. The expression of Hip gene was up regulated in QGY-7701 after treated with KAAD-cyclopamine （t = 4. 70, P 〈 0. 05 ）. Conclusion The expression of main Hedgehog signaling pathway components were detected in HCC, KAAD-cyclopamine specifically inhibited the Hedgehog signaling pathway.