Department of Endocrinology and Diabetology, Medical Faculty, University of Dusseldorf, D-40225 Duesseldorf, Germany; Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Medical Faculty, University of Dusseldorf, D-40225 Duesseldorf, Germany.
J Steroid Biochem Mol Biol. 2014 Jan;139:7-15. doi: 10.1016/j.jsbmb.2013.09.007. Epub 2013 Sep 21.
Hedgehog (Hh)-signaling pathway is important in embryonic development. Activation of Hh-signaling is associated with tumorigenesis. Recent studies demonstrate that Hh-signaling is involved in the development of the adrenal gland in mice and is important in regulating adrenal proliferation. We studied the expression of Sonic hedgehog (SHH), Smoothened (SMO), Patched1 (PTCH1) and GLI family zinc finger 1 (GLI1) in human adrenal and in adrenocortical tumors using immunohistochemistry and semi-quantitative reverse transcriptase-polymerase chain reaction. Modulation of GLI1 and SMO messenger ribonucleic acid (mRNA) expression was investigated with forskolin. The role of Hh-signaling was studied in NCI-H295R cells and in an immortalized primary cell line using the Hh-agonist smoothened agonist (SAG) and the Hh-antagonist cyclopamine. The Hh-pathway components SHH, GLI1, PTCH1 and SMO were detectable in all adrenal glands. While in cortisol-producing adenomas (CPA), Hh-signaling expression levels were comparable to that in normal adrenal cortex, a much higher mRNA expression of GLI1, SMO and SHH was observed in non-producing adenomas (NPA). Interestingly, stimulation of cultured adrenal cells with forskolin led to a decrease in expression of GLI1 and SMO mRNAs. Antagonism of Hh-signaling resulted in a lower proliferation rate of adrenocortical cells, while Hh-agonism had no significant effect on adrenal cell proliferation. Our data show Hh-signaling activity in adult adrenal glands. Activation of the PKA pathway results in lower expression of Hh-signaling proteins. This might explain the lower expression of the Hh components GLI1 and SMO in CPA in comparison to the higher expression in NPA. Hh-signaling might be involved in the tumorigenesis of NPA.
Hedgehog（Hh）信号通路在胚胎发育中很重要。Hh 信号的激活与肿瘤发生有关。最近的研究表明，Hh 信号参与了小鼠肾上腺的发育，并在调节肾上腺增殖方面很重要。我们使用免疫组织化学和半定量逆转录聚合酶链反应研究了 Sonic Hedgehog（SHH）、Smoothened（SMO）、Patched1（PTCH1）和 GLI 家族锌指 1（GLI1）在人肾上腺和肾上腺皮质肿瘤中的表达。用 forskolin 研究了 GLI1 和 SMO 信使 RNA（mRNA）表达的调节。使用 Hh-激动剂 smoothened 激动剂（SAG）和 Hh 拮抗剂 cyclopamine 在 NCI-H295R 细胞和永生化原代细胞系中研究了 Hh 信号的作用。在所有肾上腺中均可检测到 Hh 通路成分 SHH、GLI1、PTCH1 和 SMO。虽然在产生皮质醇的腺瘤（CPA）中，Hh 信号表达水平与正常肾上腺皮质相当，但在非产生腺瘤（NPA）中观察到 GLI1、SMO 和 SHH 的 mRNA 表达更高。有趣的是，用 forskolin 刺激培养的肾上腺细胞导致 GLI1 和 SMO mRNA 表达降低。Hh 信号的拮抗作用导致肾上腺皮质细胞增殖率降低，而 Hh 激动作用对肾上腺细胞增殖没有显著影响。我们的数据显示成人肾上腺中存在 Hh 信号活性。PKA 途径的激活导致 Hh 信号蛋白表达降低。这可能解释了与 NPA 中较高表达相比，CPA 中 Hh 成分 GLI1 和 SMO 的表达较低。Hh 信号可能参与了 NPA 的肿瘤发生。
