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.     

Updates and review of neoplastic paediatric neuropathology

Tumours of the central nervous system are the second most common type of malignancy in the paediatric population, after haematopoietic malignancies. With the 2016 edition of the WHO Classification of the Tumours of the Central Nervous System (CNS), a diagnostic approach to paediatric CNS malignancies has been adopted, which increasingly incorporates molecular parameters, as well as histologic features. This classification system represents a major restructuring of many paediatric central nervous system tumours. This review aims to highlight the areas in the WHO 2016 classification system that have undergone the greatest changes in paediatric tumours of the central nervous system, as well as to review the key histologic and clinical components of these entities. The greatest changes in classification were adopted in embryonal tumours and paediatric diffuse midline gliomas with histone H3 mutations, while low grade astrocytic and glioneuronal tumours also underwent important grading changes.     

Application of hiPSCs in tooth regeneration via cellular modulation

BackgroundInduced pluripotent stem cell (iPSC)-based technology provides limitless resources for customized development of organs without any ethical concerns. In theory, iPSCs generated from terminally differentiated cells can be induced to further differentiate into all types of organs that are derived from the embryonic germ layers. Since iPSC reprogramming technology is relatively new, extensive efforts by the researchers have been put together to optimize the protocols to establish in vitro differentiation of human iPSCs (hiPSCs) into various desirable cell types/organs.HighlightsIn the present study, we review the potential application of iPSCs as an efficient alternative to primary cells for modulating signal molecules. Furthermore, an efficient culture system that promotes the differentiation of cell lineages and tissue formation has been reviewed. We also summarize the recent studies wherein tissue engineering of the three germ layers has been explored. Particularly, we focus on the current research strategies for iPSC-based tooth regeneration via molecular modulation.ConclusionIn recent decades, robust knowledge regarding the hiPSC-based regenerative therapy has been accumulated, especially focusing on cellular modulation. This review provides the optimization of the procedures designed to regenerate specific organs.     

An H3F3A K27M‐mutation in a sonic hedgehog medulloblastoma

Medulloblastomas are malignant embryonal brain tumours that may harbour mutations in histone‐modifying genes, while mutations in histone genes have not been detected to date. We here describe the first SHH medulloblastoma with H3 K27M mutation. This may have diagnostic implications as H3 K27M mutations are the hallmark of diffuse midline gliomas, H3 K27M mutant, WHO grade IV. Medulloblastomas arise in midline structures and thus must not be mistaken for DMG when using an antibody detecting the H3 K27M mutation.     

Hedgehog信号通路相关基因在大肠癌的表达及其临床意义

目的：研究Hedgehog信号通路相关基因SHH、SMO、GLI1在大肠癌中的表达及其临床意义。方法：用RT-PCR检测43例大肠癌切除标本的癌组织和距离癌10cm以上的癌旁组织的SHH、SMO、GLI1 mRNA表达的阳性率,并与20例非肠癌患者的正常大肠组织对照,分析其与大肠癌患者临床和病理各变量的相关性。结果：大肠癌组织SHH mRNA表达阳性率为27．9％,与癌旁组织的18．6％比较,差异无显著性（P〉0．05）,但显著高于正常组织的0％（P〈0．05）。大肠癌组织SMO、GLI1 mRNA表达阳性率分别为83．7％、34．9％,显著高于癌旁组织的58．1％、16．3％及正常组织的0％、0％（P〈0．05）。SHH、SMO、GLI1 mRNA表达阳性率之间并无相关性,阳性率与患者的年龄、性别、临床分期、肿瘤部位、肿瘤浸润深度、病理分型等变量均无相关性（P〉0．05）。结论：Hedgehog信号通路相关基因SHH、SMO、GLI1 mRNA在大肠癌组织中表达阳性率显著增高,其表达与临床和病理各变量不相关。     

卵巢和卵巢肿瘤中Hedgehog 信号通路的表达

目的探讨正常卵巢和卵巢肿瘤中Hedgehog信号通路的表达。方法采用RT—PCR和免疫组织、细胞化学染色检测26例卵巢肿瘤组织、3例卵巢癌细胞株（SKOV3、A2780和COC1）和7例正常卵巢组织中Hedgehog信号通路的信号分子SHH、IHH、PTCH、SMO和GLI1的mRNA和蛋白表达情况;通过实时定量RT—PCR对随机抽取的11例卵巢肿瘤组织和5例正常卵巢组织进行PTCH和GLI1 mRNA水平的比较。结果SHH、IHH、PTCH、SMO和GLI1的mRNA在卵巢肿瘤组织中均有表达;SHH mRNA在正常卵巢组织中不表达,而IHH、PTCH、SMO和GLI1的mRNA在正常卵巢组织中有表达;在卵巢肿瘤组织中,PTCH和GLI1的mRNA表达水平高于正常组织（P〈0．05）。SHH、IHH、PTCH、SMO和GLI1蛋白在卵巢肿瘤组织中均呈阳性表达,在正常卵巢组织中不表达。卵巢癌细胞株SKOV3、A2780和COC1均有IHH、PTCH、SMO和GLI1的mRNA和蛋白的表达;SHH仅在SKOV3和A2780中表达。结论卵巢肿瘤中存在Hedgehog信号通路,在部分卵巢肿瘤中有Hedgehog信号通路过度激活的现象。