Enhanced expression of hedgehog signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions.

The hedgehog (Hh)-signaling pathway plays an essential role in normal development. Deregulation of this pathway is responsible for several types of cancers. The aim of this study was to determine the expression pattern and the extent of Hh-signaling molecules in squamous cell carcinoma of uterine cervix and its precursor lesions. A total of 106 uterine cervical cancers and related lesions (37 squamous cell carcinomas, 23 cervical intraepithelial neoplasia (CIN) III, 10 CIN II, four CIN I, 32 normal cervical epithelia) were immunohistochemically analyzed with anti-Shh, Indian Hh (Ihh), Patched (PTCH), Smoothened (Smo), Gli-1, Gli-2, Gli-3 antibodies on paraffin blocks. The results showed that the expression of all the Hh-signaling molecules was greatly enhanced in uterine cervical tumors, including carcinoma and its precursor lesions. The staining pattern was mainly cytoplasmic except for Gli-1/2, whose expression was observed in both cytoplasm and nucleus. In case of Ihh, PTCH, Smo and Gli-1, their expression in normal epithelium was completely absent or rare. The expression of all the seven Hh-signaling molecules mentioned above was significantly increased in CIN II/III and carcinoma, compared with that in normal epithelium (P < 0.05). The expression of Shh was increased by double; the first increase occurred in normal epithelium-CIN transition, and the second, during the progression of CIN to carcinoma. These results strongly suggest that the Hh-signaling pathways were extensively activated in carcinoma and CIN of uterine cervix. In conclusion, the Hh-signaling pathways may be involved in carcinogenesis of squamous cell carcinoma of uterine cervix and can be considered as a potential therapeutic target.     

Expression of Sonic hedgehog pathway genes is altered in colonic neoplasia

The Hedgehog (Hh) signalling pathway is crucial for normal development and patterning of numerous human organs including the gut. Hh proteins are also expressed during gastric gland development and gastric epithelial differentiation in adults. Recently, dysregulation of these developmentally important genes has been implicated in cancer, leading to the present study of the expression of Hh signalling proteins in colon cancer. In this study, normal colon and colonic lesions (hyperplastic polyp, adenoma, and colonic adenocarcinoma) were examined by immunohistochemistry using antibodies against Hh signalling molecules: the secreted protein Sonic hedgehog (SHH), its receptor Patched (PTCH), and the PTCH-associated transmembrane protein Smoothened (SMOH). The study shows that Hh signalling pathway members are expressed in normal colonic epithelium. SHH was expressed at the top of the crypts and in a few basally located cells, while PTCH was detected in the neuroendocrine cells and SMOH at the brush border of superficial epithelium. RT-PCR analysis of laser-microdissected crypts from normal human colon confirmed that mRNAs encoding these proteins were expressed in colonic epithelium. Expression of SHH, PTCH, and SMOH was up-regulated in hyperplastic polyps, adenomas, and adenocarcinomas of the colon, and SHH expression correlated with increased expression of the proliferation marker Ki-67 in all lesions examined. To address whether the Hh signalling pathway is functional in the gut, the effect of Shh on epithelial cells in vitro was explored by treating primary murine colonocytes with either Shh peptide or neutralizing anti-Shh antibody. The proportion of cells in the S-phase was assessed by bromodeoxyuridine (BrdU) incorporation. It was found that exogenous Shh promotes cell proliferation in colonocytes, while anti-Shh inhibits proliferation, suggesting that Shh is required during proliferation of epithelial cells in vitro. It is suggested that SHH is required during epithelial proliferation in the colon and that there is a possible role for Hh signalling in epithelial colon tumour progression in vivo.     

A direct requirement for Hedgehog signaling for normal specification of all ventral progenitor domains in the presumptive mammalian spinal cord

The hedgehog signaling pathway organizes the developing ventral neural tube by establishing distinct neural progenitor fates along the dorsoventral axis. Smoothened (Smo) is essential for all Hedgehog (Hh) signaling, and genetic inactivation of Smo cells autonomously blocks the ability of cells to transduce the Hh signal. Using a chimeric approach, we examined the behavior of Smo null mutant neural progenitor cells in the developing vertebrate spinal cord, and we show that direct Hh signaling is essential for the specification of all ventral progenitor populations. Further, Hh signaling extends into the dorsal half of the spinal cord including the intermediate Dbx expression domain. Surprisingly, in the absence of Sonic hedgehog (Shh), we observe the presence of a Smo-dependent Hh signaling activity operating in the ventral half of the spinal cord that most likely reflects Indian hedgehog (Ihh) signaling originating from the underlying gut endoderm. Comparative studies of Shh, Smo, and Gli3 single and compound mutants reveal that Hh signaling acts in part to specify neural cell identity by counteracting the repressive action of Gli3 on p0, p1, p2, and pMN formation. However, whereas these cell identities are restored in Gli3/Smo compound mutants, correct stratification of the rescued ventral cell types is lost. Thus, Hh signaling is essential for organizing ventral cell pattern, possibly through the control of differential cell affinities.     

Hedgehog signaling regulates differentiation from double-negative to double-positive thymocyte

The hedgehog (Hh) signaling pathway is involved in the development of many tissues. Here we show that sonic hedgehog (Shh) is involved in thymocyte development. Our data suggest that termination of Hh signaling is necessary for differentiation from CD4-CD8-double-negative (DN) to CD4+CD8+ double-positive (DP) thymocyte. Shh is produced by the thymic stroma, and Patched and Smoothened (Smo), the transmembrane receptors for Shh, are expressed in DN thymocytes. A neutralizing monoclonal antibody against Shh increases differentiation of DN to DP thymocytes, and Shh protein arrests thymocyte differentiation at the CD25+ DN stage, after T cell receptor beta (TCRbeta) gene rearrangement. We show that one consequence of pre-TCR signaling is downregulation of Smo, allowing DN thymocytes to proliferate and differentiate.     

Expression of hedgehog pathway components in prostate carcinoma microenvironment: shifting the balance towards autocrine signalling

Tzelepi V, Karlou M, Wen S, Hoang A, Logothetis C, Troncoso P & Efstathiou E
(2011) Histopathology 58, 1037–1047
Expression of hedgehog pathway components in prostate carcinoma microenvironment: shifting the balance towards autocrine signalling Aims: The hedgehog (Hh) signalling pathway has been implicated in the pathogenesis and aggressiveness of prostate cancer through epithelial–mesenchymal interactions. The aim of this study was to elucidate the cell‐type partitioned expression of the Hh pathway biomarkers in the non‐neoplastic and tumour microenvironments and to correlate it with the grade and stage of prostate cancer. Methods and results: Expression of the Hh pathway components (Shh, Smo, Ptch, Gli1) in the microenvironment of non‐neoplastic peripheral zone (n = 119), hormone‐naive primary prostate carcinoma (n = 141) and castrate‐resistant bone marrow metastases (n = 53) was analysed using immunohistochemistry in tissue microarrays and bone marrow sections. Results showed that epithelial Shh, Smo and Ptch expression was up‐regulated, whereas stromal Smo, Ptch, and Gli1 expression was down‐regulated in prostate carcinomas compared to non‐neoplastic peripheral zone tissue. Ptch expression was modulated further in high‐grade and high‐stage primary tumours and in bone marrow metastases. Hh signalling correlated with ki67 and vascular endothelial growth factor (VEGF) but not with CD31 expression. Conclusion: Our results highlight the importance of Hh‐mediated epithelial–mesenchymal interactions in the non‐neoplastic prostate and imply that shifting the balance from paracrine towards autocrine signalling is important in the pathogenesis and progression of prostate carcinoma.     

子宫颈癌中Hedgehog信号通路蛋白表达与人乳头状瘤病毒16型感染的关系

目的 探讨Hedgehog(Hh)信号通路蛋白在宫颈癌及其癌前病变中的临床病理学意义,并分析其与人乳头状瘤病毒(HPV)16型感染的关系.方法 32例正常宫颈上皮、71例宫颈上皮内瘤变(CIN;CIN Ⅰ 28例,CIN Ⅱ 18例,CIN Ⅲ25例)和80例宫颈鳞状细胞癌共183例选自延边大学医院、延边妇幼保健院和延边肿瘤医院病理科存档蜡块.应用PCR技术检测上述组织中HPV16型的感染情况,并应用Shh、Ihh、Ptch和Smo 4种Hh信号通路蛋白抗体、组织芯片和免疫组织化学EnVision法检测Hh信号通路蛋白在上述病变组织中的表达情况.结果 Shh、Ihh、Ptch和Smo在正常宫颈黏膜上皮中为弱阳性,而在宫颈癌和CIN Ⅲ中呈强阳性,其表达率均显著高于正常宫颈黏膜上皮(P均<0.05).80例官颈癌标本中HPV16阳性率是77.5%(62/80),而且Shh蛋白的强阳性率在HPV16型阳性的宫颈癌组织中显著高于HPV16阴性组(P<0.05).结论 Hh信号通路蛋白过表达可以作为宫颈癌及其癌前病变的早期辅助诊断指标并有望成为宫颈癌靶向治疗的新靶点,而且Shh蛋白的过表达与HPV16型感染密切相关.     

Sonic hedgehog信号通路在单侧输尿管梗阻大鼠肾组织中的表达变化及意义

 目的：探讨Sonic hedgehog（Shh）信号通路在单侧输尿管梗阻（UUO）大鼠肾组织中的表达变化及意义。方法：将48只SD大鼠随机分为UUO模型组（n=24）和假手术组（n=24）,梗阻术3、7和14 d后取其梗阻侧肾脏组织。用HE和Masson染色检测肾间质纤维化程度,免疫组织化学染色检测Shh通路分子Shh、Ptch1、Smo、Gli1及III型胶原的蛋白表达,酶联免疫吸附实验（ELISA）检测肾组织中TGF-β₁和Shh含量,real-time RT-PCR检测TGF-β₁、I和III型胶原及Shh通路分子mRNA表达。结果：HE和Masson染色显示,梗阻侧肾组织出现明显的纤维化病变,且随时间延长而加剧。TGF-β₁、I和III型胶原含量在梗阻肾中表达明显增高（P<0.05）。同时,Shh信号通路分子Shh、Smo和Gli mRNA和蛋白在梗阻肾中表达明显升高（P<0.05）,而Ptch1 mRNA和蛋白的表达下调（P<0.01）,提示Shh信号被激活。相关分析表明,Shh信号起始信号Shh水平的升高与TGF-β₁含量增加呈明显的相关。结论：UUO大鼠诱导肾间质纤维化发生过程中,Shh信号通路分子被激活,推测可能的机制是活化的Shh信号通路诱导TGF-β₁表达和释放,导致肾间质纤维化。     

Sonic hedgehog阻断抗体增强外周血单个核细胞抗宫颈癌HeLa细胞的作用

目的: 探讨Sonic hedgehog(Shh)阻断抗体对外周血单个核细胞(PBMCs)抗宫颈癌HeLa细胞作用的影响。方法: 免疫细胞化学技术和RT-PCR法检测Shh及其信号分子在HeLa 细胞中的表达;Ficoll密度梯度离心法分离正常人PBMCs,并与HeLa细胞建立共培养体系;于共培养体系中加入Shh阻断抗体,流式细胞术检测CD3、CD69和CD71分子表达;ELISA法检测细胞因子IFN-γ、IL-10和IL-4分泌;显微镜观察PBMCs 对HeLa细胞的杀伤。结果: HeLa细胞表达Shh及其信号分子,HeLa细胞传代6次对Shh的表达水平没有影响;共培养体系中CD3⁺细胞增多;Shh阻断抗体可以促进CD69、CD71表达和IFN-γ的分泌,但抑制IL-10分泌,对IL-4分泌没有显著影响;Shh阻断抗体增强PBMCs对HeLa细胞的杀伤。结论: Shh阻断抗体可以促进PBMCs活化,增强PBMCs抗宫颈癌HeLa细胞的作用。     

Intraflagellar transport, cilia, and mammalian Hedgehog signaling: analysis in mouse embryonic fibroblasts.

Genetic studies in the mouse have shown that Intraflagellar Transport (IFT) is essential for mammalian Hedgehog (Hh) signal transduction. In this study, we take advantage of wild type and IFT mutant mouse embryonic fibroblasts (MEFs) to characterize additional aspects of the relationship between IFT and Hh signaling. Exposure to Sonic hedgehog (Shh) ligand or expression of an activated allele of Smo, SmoA1, activates an Hh reporter in wild-type MEFs, but not in MEFs derived from embryos that lack IFT172 or the Dync2h1 subunit of the retrograde IFT motor. Similarly, decreased activity of either Sufu or PKA, two negative regulators of Hh signal transduction, activates the pathway in wild-type, but not IFT mutant, MEFs. In contrast to wild-type MEFs, Smo is constitutively present in the cilia of Dync2h1 mutant MEFs. This finding suggests that IFT-dependent trafficking of Hh pathway components through the cilium is essential for their function.     

The seven-transmembrane receptor smoothened cell-autonomously induces multiple ventral cell types

Sonic Hedgehog (Shh) is a secreted protein that controls cell fate and mitogenesis in the developing nervous system. Here we show that a constitutively active form of Smoothened (Smo-M2) mimics concentration-dependent actions of Shh in the developing neural tube, including activation of ventral marker genes (HNF3beta, patched, Nkx2.2, netrin-1), suppression of dorsal markers (Pax-3, Gli-3, Ephrin A5) and induction of ventral neurons (dopaminergic, serotonergic) and ventrolateral motor neurons (Islet-1+, Islet-2+, HB9+) and interneurons (Engrailed-1+, CHX10+). Furthermore, Smo-M2's patterning activities were cell autonomous, occurring exclusively in cells expressing Smo-M2. These findings suggest that Smo is a key signaling component in the Hh receptor and that Shh patterns the vertebrate nervous system as a morphogen, rather than through secondary relay signals.     

Smoothened transduces Hedgehog signal by physically interacting with Costal2/Fused complex through its C-terminal tail

The Hedgehog (Hh) family of secreted proteins controls many aspects of growth and patterning in animal development. The seven-transmembrane protein Smoothened (Smo) transduces the Hh signal in both vertebrates and invertebrates; however, the mechanism of its action remains unknown. We found that Smo lacking its C-terminal tail (C-tail) is inactive, whereas membrane-tethered Smo C-tail has constitutive albeit low levels of Hh signaling activity. Smo physically interacts with Costal2 (Cos2) and Fused (Fu) through its C-tail. Deletion of the Cos2/Fu-binding domain from Smo abolishes its signaling activity. Moreover, overexpressing Cos2 mutants that fail to bind Fu and Ci but retain Smo-binding activity blocks Hh signaling. Taken together, our results suggest that Smo transduces the Hh signal by physically interacting with the Cos2/Fu protein complex.     

Suppression of hedgehog signaling regulates hepatic stellate cell activation and collagen secretion

Hepatic stellate cells (HSCs) play an important role in liver fibrosis. This study investigates the expression of hedgehog in HSC and the role of hedgehog signaling on activation and collagen secretion of HSC. Liver ex vivo perfusion with collagenase IV and density gradient centrifugation were used to isolate HSC. Expression of hedgehog signaling components Ihh, Smo, Ptc, Gli2 and Gli3 in HSC were detected by RT-PCR. Hedgehog siRNA vectors targeting Ihh, Smo and Gli2 were constructed and transfected into HSC respectively. Suppression of hedgehog signaling were detected by SYBR Green fluorescence quantitative RT-PCR. Effects of hedgehog signaling inhibition on HSC activation and collagen I secretion were analyzed. Hedgehog signaling components Ihh, Smo, Ptc, Gli2 and Gli3 were expressed in HSC. siRNA vectors targeting Ihh, Smo and Gli2 were successfully constructed and decreased target gene expression. Suppression of hedgehog signaling significantly decreased the expression of α-SMA in HSC (P<0.01). Collagen type I secretion of HSC were also significantly decreased (P<0.01). In summary, HSC activation and collagen secretion can be regulated by hedgehog signaling. Hedgehog may play a role in the pathogenesis of liver fibrosis.     

白藜芦醇对NIH3T3细胞Shh信号通路的影响

目的探讨白藜芦醇对NIH3T3细胞Shh信号通路的影响。方法实验分为对照组和白藜芦醇组。白藜芦醇处理NIH3T3细胞24 h。CCK-8法测定细胞活力,免疫荧光法检测初级纤毛蛋白(Ac-tu)、Smo和Gli-1的表达,Western blotting法检测Shh、Ptc、Smo、Gli-1蛋白的表达。结果 1.0.5和1μmol/L白藜芦醇组(0.679±0.047,0.774±0.054)细胞活力分别较对照组(0.585±0.039)明显增强(P<0.05),其中以1μmol/L白藜芦醇组最强。之后随白藜芦醇浓度(10、20、40、80μmol/L)的增高,细胞活力逐渐降低(0.428±0.043,0.395±0.031,0.373±0.017,0.361±0.016),且均较对照组明显减弱(P<0.05),而0.1μmol/L(0.602±0.065)和5μmol/L组(0.556±0.041)细胞活力与对照组比较差异无显著性(P>0.05)。2.NIH3T3细胞表达Ac-tu、Shh、Ptc-1、Smo、Gli-1从蛋白,有1根初级纤毛,Smo和Gli-1蛋白位于细胞质。白藜芦醇处理24 h时,Gli-1从细胞质进入细胞核,Smo从细胞质进入初级纤毛,且Shh(0.756±0.659比0.441±0.769,P<0.05)、Ptc-1(0.655±0.347比0.351±0.026,P<0.05)、Smo(0.779±0.064比0.451±0.035,P<0.05)和Gli-1(0.856±0.044比0.560±0.058,P<0.05)蛋白表达较对照组高。结论白藜芦醇可能通过激活Shh信号通路增强NIH3T3细胞的活力。     

Monoaminergic regulation of Sonic hedgehog signaling cascade expression in the adult rat hippocampus

Monoamines are implicated in the modulation of adult hippocampal neurogenesis in depression models and following chronic antidepressant treatment. Given the key role of Sonic hedgehog (Shh) in adult neurogenesis, we examined whether monoaminergic perturbations regulate the expression of Shh or its co-receptors Smoothened (Smo) and Patched (Ptc). Combined depletion of both serotonin and norepinephrine with para-chlorophenylalanine (PCPA) resulted in a significant decrease in Smo and Ptc mRNA within the dentate gyrus subfield of the hippocampus. However, selective depletion of serotonin, using the serotonergic neurotoxin 5,7-dihyrdroxytryptamine (5,7-DHT), or norepinephrine, using the noradrenergic neurotoxin DSP-4, did not alter expression of Shh and its co-receptors, Smo and Ptc. Acute treatment with the monoamine releasing agent, para-chloroamphetamine (PCA) significantly upregulated Smo mRNA within the dentate gyrus. However, acute or chronic treatment with pharmacological antidepressants that modulate monoaminergic neurotransmission did not regulate Shh cascade expression. These results indicate that robust changes in monoamine levels can regulate the expression of the Shh signaling cascade in the adult rodent brain.     

Transcriptional silencing of hedgehog-interacting protein by CpG hypermethylation and chromatic structure in human gastrointestinal cancer

Hedgehog-interacting protein (HHIP) was identified as a putative antagonist of the Hh pathway and as a target of Hh signalling. Our aim was to clarify the expression profiles and epigenetic alterations of the HHIP gene in gastrointestinal cancer. The expression and promoter epigenetic status of HHIP in cancer cell lines and freshly resected gastrointestinal cancer tissues were examined using RT-PCR, tissue microarray analysis, methylation-specific PCR, and chromatin immunoprecipitation assay. Cells were treated with the demethylating agent 5-aza-2'-deoxycytidine and/or histone deacetylase inhibitor trichostatin A. WST-8 assays and in vitro invasion assays after treatment with HHIP-specific siRNA were performed. HHIP expression levels were reduced in most of the gastrointestinal cancer cell lines and in a certain subset of cancer tissues, and these were correlated with promoter hypermethylation. A heterochromatic structure characterized by neither acetylated H3 nor acetylated H4, and histone H3 lysine 9 hypermethylation and histone H3 lysine 4 hypomethylation was observed in cancer cells in which the HHIP gene was aberrantly silenced. On the other hand, overexpression of the HHIP gene was also found in some cancer tissues and there were significant correlations between protein expression levels of HHIP and those of Sonic hedgehog (Shh), Indian hedgehog, Patched, and glioma-associated oncogene homologue-1. An association was found between lymph node metastasis and HHIP silencing in colorectal cancer tissues with strong Shh expression and between advanced TNM stage and HHIP silencing in diffuse-type gastric cancer tissues with strong Shh expression. Down-regulation of HHIP expression by siRNA resulted in a significant increase in colon cancer cell growth and invasion in vitro. Silencing of the HHIP gene due to hypermethylation and chromatin remodelling appears to be frequently involved in gastrointestinal tumourigenesis.