Hedgehog signaling and response to cyclopamine differ in epithelial and stromal cells in benign breast and breast cancer
Hedgehog signaling and response to cyclopamine differ in epithelial and stromal cells in benign breast and breast cancer
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DOI：
10.4161/cbt.5.6.2906
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发表时间：
2006-06-01
影响因子：
3.6
通讯作者：
Frost, Andra R.
中科院分区：
文献类型：
--
作者：
Mukherjee, Shibani;Frolova, Natalya;Frost, Andra R.
hedgehog通路调节发育过程中上皮-间充质相互作用、分化、增殖和存活。刺激hedgehog信号传导诱导多器官癌症的致癌作用或促进细胞存活。使用实时定量PCR、激光捕获显微切割和免疫组织化学，在良性乳腺癌和乳腺癌的上皮细胞和间质成纤维细胞中鉴定了hedgehog途径成员patched 1（PTCH 1）、smoothened、GLI 1、GLI 2和3种hedgehog配体的独特表达模式。与非癌性上皮细胞相比，Hedgehog配体在一些癌性上皮细胞系中以更高的水平表达。相应地，在癌上皮细胞系中，Hedgehog信号传导的转录因子和转录产物GLI 1的表达增加了8倍;然而，在许多细胞类型中也是Hedgehog信号传导的转录靶点的PTCH 1没有增加。GLI 1蛋白和mRNA，PTCH 1和音刺猬（SHH）蛋白在10例乳腺癌中的3例中升高;然而，PTCH 1转录本并没有持续增加。刺猬介导的转录，如GLI依赖性启动子活性的报告和GLI 1转录本的表达所示，在MDA-MB-435癌上皮细胞和MCF 10AT上皮细胞（一种来自良性乳腺的细胞系）中，刺猬通路抑制剂环巴胺降低。然而，环巴胺降低了癌上皮细胞系（包括MDA-MB-435）的活力，但并不特异性影响良性乳腺的成纤维细胞或上皮细胞（包括MCF 10AT）。用Sonic Hedgehog配体处理减少了MCF 10AT和MDA-MB-435中环帕米诱导的GLI依赖性启动子活性的降低以及MDA-MB-435的活力。这些结果表明，GLI介导的转录在癌症和良性衍生的上皮细胞的cyclopamine和音刺猬的调制，并进一步表明，刺猬信号有助于仅癌上皮细胞的存活。确定乳腺癌中GLI 1和SHH表达的增加是否表明hedgehog信号的显著增加需要进一步评估。
The hedgehog pathway regulates epithelial-mesenchymal interactions, differentiation, proliferation and survival during development. Stimulation of hedgehog signaling induces carcinogenesis or promotes cell survival in cancers of multiple organs. Using real-time, quantitative PCR, laser capture microdissection, and immunohistochemistry, distinctive patterns of expression of the hedgehog pathway members patched 1 (PTCH1), smoothened, GLI1, GLI2 and the 3 hedgehog ligands were identified for epithelial cells and stromal fibroblasts in benign breast and breast cancer. Hedgehog ligands were expressed at higher levels in some cancer epithelial cell lines compared to noncancerous epithelial cells. Correspondingly, expression of GLI1, a transcription factor and transcriptional product of hedgehog signaling, was increased 8-fold in cancer epithelial cell lines; however, PTCH1, also a transcriptional target of hedgehog signaling in many cell types, was not increased. GLI1 protein and mRNA, and PTCH1 and sonic hedgehog (SHH) proteins were elevated in 3 of 10 breast cancers; however, PTCH1 transcripts were not consistently increased. Hedgehog-mediated transcription, as indicated by a reporter of GLI-dependent promoter activity and by expression of GLI1 transcripts, was reduced by the hedgehog pathway inhibitor cyclopamine in both MDA-MB-435 cancer epithelial cells and MCF10AT epithelial cells, a cell line derived from benign breast. However, cyclopamine reduced viability of cancer epithelial cell lines, including MDA-MB-435, but did not specifically affect fibroblasts or epithelial cells from benign breast, including MCF10AT. Treatment with sonic hedgehog ligand diminished the cyclopamine-induced reduction in GLI-dependent promoter activity in MCF10AT and MDA-MB-435 and viability of MDA-MB-435. These results demonstrate modulation of GLI-mediated transcription in both cancer and benign-derived epithelial cells by cyclopamine and sonic hedgehog, and further suggest that hedgehog signaling contributes to the survival of only the cancer epithelial cells. Determination as to whether the increase in GLI1 and SHH expression in breast cancer indicates a significant increase in hedgehog signaling will require further evaluation.