Methylation analysis of EDNRB in human colon tissues of Hirschsprung's disease

The roles of non-coding RNAs in Hirschsprung's disease

Hirschsprung's disease (HSCR) is a congenital disorder characterized by the absence of ganglion cells in the colon, leading to various intestinal complications. The etiology of HSCR stems from complex genetic and environmental interactions, of which the intricate roles of non-coding RNAs (ncRNAs) are a key area of research. However, the roles of ncRNAs in the pathogenesis of HSCR have not been fully elucidated. In order to understand the variety of symptoms caused by HSCR and develop new therapeutic approaches, it is essential to understand the underlying biological genetic basis of HSCR. This review presents a comprehensive overview of the current understanding regarding the involvement of ncRNAs in HSCR, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). Additionally, it provides a summary of the molecular mechanisms through which ncRNAs regulate the expression of genes related to the proliferation, migration, and differentiation of intestinal neural crest cells, thereby contributing to the advancement of HSCR research.

DNA methylation in necrotizing enterocolitis

Epigenetic modifications, such as DNA methylation, are enzymatically regulated processes that directly impact gene expression patterns. In early life, they are central to developmental programming and have also been implicated in regulating inflammatory responses. Research into the role of epigenetics in neonatal health is limited, but there is a growing body of literature related to the role of DNA methylation patterns and diseases of prematurity, such as the intestinal disease necrotizing enterocolitis (NEC). NEC is a severe intestinal inflammatory disease, but the key factors that precede disease development remain to be determined. This knowledge gap has led to a failure to design effective targeted therapies and identify specific biomarkers of disease. Recent literature has identified altered DNA methylation patterns in the stool and intestinal tissue of neonates with NEC. These findings provide the foundation for a new avenue in NEC research. In this review, we will provide a general overview of DNA methylation and then specifically discuss the recent literature related to methylation patterns in neonates with NEC. We will also discuss how DNA methylation is used as a biomarker for other disease states and how, with further research, methylation patterns may serve as potential biomarkers for NEC.

High incidence of EDNRB gene mutation in seven southern Chinese familial cases with Hirschsprung's disease

PURPOSE

Hirschsprung's disease (HSCR) is the leading cause of neonatal functional intestinal obstruction, which has been identified in many familial cases. HSCR, a multifactorial disorder of enteric nervous system (ENS) development, is associated with at least 24 genes and seven chromosomal loci, with RET and EDNRB as its major genes. We present a genetic investigation of familial HSCR to clarify the genotype-phenotype relationship.

METHODS

We performed whole exome sequencing (WES) on Illumina HiSeq X Ten platform to investigate genetic backgrounds of core family members, and identified the possibly harmful mutation genes. Mutation carriers and pedigree relatives were validated by Sanger sequencing for evaluating the gene penetrance.

RESULTS

Four familial cases showed potential disease-relative variants in EDNRB and RET gene, accounting for all detection rate of 57.1%. Three familial cases exhibited strong pathogenic variants as frameshift or missense mutations in EDNRB gene. A novel c.367delinsTT mutation of EDNRB was identified in one family member. The other two EDNRB mutations, c.553G>A in family 2 and c.877delinsTT in family 5, have been reported in previous literatures. The penetrance of EDNRB variants was 33-50% according mutation carries. In family 6, the RET c.1858T>C (C620R) point mutation has previously been reported to cause HSCR, with 28.5% penetrance.

CONCLUSION

We identified a novel EDNRB (deleted C and inserted TT) mutation in this study using WES. Heterozygote variations in EDNRB gene were significantly enriched in three families and RET mutations were identified in one family. EDNRB variants showed an overall higher incidence and penetrance than RET in southern Chinese families cases.

Aberrant high expression of the TET1 gene in Hirschsprung's disease

BACKGROUND

The pathogenesis of Hirschsprung's disease (HSCR) remains unclear but might involve genes participating in neural crest development. Gene methylation controls the expression of many genes and is involved in the development and migration of neural crest cells, but the involvement of demethylation in HSCR is unknown. This study aimed to investigate the expression of ten-eleven translocation methylcytosine dioxygenase 1 (TET1) (a demethylation protein) in patients with HSCR.

METHODS

This is a retrospective study of surgical specimens from paediatric patients with and without HSCR (e.g., intussusception and incarcerated hernia) obtained from 07/2015 to 08/2017. TET1 expression was determined by qRT-PCR, western blotting, and immunohistochemistry. The levels of 5-hydroxymethylcytosine were determined by the dot blot assay.

RESULTS

The specimens of 35 patients with HSCR and 25 controls were collected. The median TET1 mRNA expression values were 1.028 [HSCR-stenotic (S)], 0.908 [HSCR-dilated (D)], and 0.467 (control) (HSCR-S vs. control: P = 0.002; HSCR-D vs. control: P = 0.008; HSCR-S vs. HSCR-D: P = 0.44). TET1 protein levels followed a similar pattern. The intensity of immunostaining identified higher expression of TET1 in HSCR colon tissues compared with control tissues. The 5-hmC levels in HSCR stenotic segment samples were significantly higher than those in controls.

CONCLUSION

The expression of TET1 is higher in paediatric patients with HSCR than in controls. DNA demethylation initiated by TET1 may be related to HSCR, which demonstrates that TET1 may play a role in the development of HSCR.

The impact of NRG1 expressions and methylation on multifactorial Hirschsprung disease

Background

Hirschsprung disease (HSCR) is a complex genetic disorder characterized by the lack of ganglion cells in the intestines. A current study showed that the NRG1 rare variant frequency in Indonesian patients with HSCR is only 0.9%. Here, we investigated the impact of NRG1 expressions and methylation patterns on the pathogenesis of HSCR.

Methods

This cross-sectional study determined NRG1 type I (HRGα, HRGβ1, HRGβ2, HRGβ3, HRGγ, and NDF43 isoforms), type II and type III expressions in both ganglionic and aganglionic colons of 20 patients with HSCR and 10 control colons by real-time polymerase chain reaction (qPCR). For methylation studies, we treated the extracted gDNA from 16 HSCR patients’ and 17 control colons with sodium bisulfate and analyzed the methylation pattern of NRG1 exon 1 with methylation-specific PCR. The samples were collected and analyzed at our institution from December 2018 to December 2020.

Results

NRG1 types I, II and III expressions were upregulated (17.2-, 3.2-, and 7.2-fold, respectively) in the ganglionic colons compared with control colons (type I: 13.32 ± 1.65 vs. 17.42 ± 1.51, p < 0.01; type II: 13.73 ± 2.02 vs. 16.29 ± 2.19, p < 0.01; type III: 13.47 ± 3.01 vs. 16.32 ± 2.58, p = 0.03; respectively); while only type I (7.7-fold) and HRGβ1/HRGβ2 (3.3-fold) isoforms were significantly upregulated in the aganglionic colons compared to the controls (type I: 14.47 ± 1.66 vs. 17.42 ± 1.51, p < 0.01; HRGβ1/HRGβ2: 13.62 ± 3.42 vs 14.75 ± 1.26, p = 0.01). Moreover, the frequency of partially methylated NRG1 was higher in the ganglionic (81%) and aganglionic (75%) colons than in the controls (59%).

Conclusions

Our study provides further insights into the aberrant NRG1 expression in the colons of patients with HSCR, both ganglionic and aganglionic bowel, which might contribute to the development of HSCR, particularly in Indonesia. Furthermore, these aberrant NRG1 expressions might be associated with its methylation pattern.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03287-1.

Development, Diversity, and Neurogenic Capacity of Enteric Glia

Enteric glia are a fascinating population of cells. Initially identified in the gut wall as the "support" cells of the enteric nervous system, studies over the past 20 years have unveiled a vast array of functions carried out by enteric glia. They mediate enteric nervous system signalling and play a vital role in the local regulation of gut functions. Enteric glial cells interact with other gastrointestinal cell types such as those of the epithelium and immune system to preserve homeostasis, and are perceptive to luminal content. Their functional versatility and phenotypic heterogeneity are mirrored by an extensive level of plasticity, illustrated by their reactivity in conditions associated with enteric nervous system dysfunction and disease. As one of the hallmarks of their plasticity and extending their operative relationship with enteric neurons, enteric glia also display neurogenic potential. In this review, we focus on the development of enteric glial cells, and the mechanisms behind their heterogeneity in the adult gut. In addition, we discuss what is currently known about the role of enteric glia as neural precursors in the enteric nervous system.

Genome-wide analysis of DNA methylation in Hirschsprung enteric precursor cells: unraveling the epigenetic landscape of enteric nervous system development

Background

Hirschsprung disease (HSCR, OMIM 142623) is a rare congenital disorder that results from a failure to fully colonize the gut by enteric precursor cells (EPCs) derived from the neural crest. Such incomplete gut colonization is due to alterations in EPCs proliferation, survival, migration and/or differentiation during enteric nervous system (ENS) development. This complex process is regulated by a network of signaling pathways that is orchestrated by genetic and epigenetic factors, and therefore alterations at these levels can lead to the onset of neurocristopathies such as HSCR. The goal of this study is to broaden our knowledge of the role of epigenetic mechanisms in the disease context, specifically in DNA methylation. Therefore, with this aim, a Whole-Genome Bisulfite Sequencing assay has been performed using EPCs from HSCR patients and human controls.

Results

This is the first study to present a whole genome DNA methylation profile in HSCR and reveal a decrease of global DNA methylation in CpG context in HSCR patients compared with controls, which correlates with a greater hypomethylation of the differentially methylated regions (DMRs) identified. These results agree with the de novo Methyltransferase 3b downregulation in EPCs from HSCR patients compared to controls, and with the decrease in the global DNA methylation level previously described by our group. Through the comparative analysis of DMRs between HSCR patients and controls, a set of new genes has been identified as potential susceptibility genes for HSCR at an epigenetic level. Moreover, previous differentially methylated genes related to HSCR have been found, which validates our approach.

Conclusions

This study highlights the relevance of an adequate methylation pattern for a proper ENS development. This is a research area that provides a novel approach to deepen our understanding of the etiopathogenesis of HSCR.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01040-6.

Goldberg-Shprintzen syndrome is determined by the absence, or reduced expression levels, of KIFBP

Goldberg-Shprintzen syndrome (GOSHS) is caused by loss of function variants in the kinesin binding protein gene (KIFBP). However, the phenotypic range of this syndrome is wide, indicating that other factors may play a role. To date, 37 patients with GOSHS have been reported. Here, we document nine new patients with variants in KIFBP: seven with nonsense variants and two with missense variants. To our knowledge, this is the first time that missense variants have been reported in GOSHS. We functionally investigated the effect of the variants identified, in an attempt to find a genotype-phenotype correlation. We also determined whether common Hirschsprung disease (HSCR)-associated single nucleotide polymorphisms (SNPs), could explain the presence of HSCR in GOSHS. Our results showed that the missense variants led to reduced expression of KIFBP, while the truncating variants resulted in lack of protein. However, no correlation was found between the severity of GOSHS and the location of the variants. We were also unable to find a correlation between common HSCR-associated SNPs, and HSCR development in GOSHS. In conclusion, we show that reduced, as well as lack of KIFBP expression can lead to GOSHS, and our results suggest that a threshold expression of KIFBP may modulate phenotypic variability of the disease.

Aberrant Expressions and Variant Screening of SEMA3D in Indonesian Hirschsprung Patients

Background: The semaphorin 3D (SEMA3D) gene has been implicated in the pathogenesis of Hirschsprung disease (HSCR), a complex genetic disorder characterized by the loss of ganglion cells in varying lengths of gastrointestinal tract. We wished to investigate the role of SEMA3D variants, both rare and common variants, as well as its mRNA expression in Indonesian HSCR patients. Methods: Sanger sequencing was performed in 54 HSCR patients to find a pathogenic variant in SEMA3D. Next, we determined SEMA3D expression in 18 HSCR patients and 13 anorectal malformation colons as controls by quantitative real-time polymerase chain reaction (qPCR). Results: No rare variant was found in the SEMA3D gene, except one common variant in exon 17, p.Lys701Gln (rs7800072). The risk allele (C) frequency at rs7800072 among HSCR patients (23%) was similar to those reported for the 1,000 Genomes (27%) and ExAC (28%) East Asian ancestry controls (p = 0.49 and 0.41, respectively). A significant difference in SEMA3D expression was observed between groups (p = 0.04). Furthermore, qPCR revealed that SEMA3D expression was strongly up-regulated (5.5-fold) in the ganglionic colon of HSCR patients compared to control colon (ΔC_T 10.8 ± 2.1 vs. 13.3 ± 3.9; p = 0.025). Conclusions: We report the first study of aberrant SEMA3D expressions in HSCR patients and suggest further understanding into the contribution of aberrant SEMA3D expression in the development of HSCR. In addition, this study is the first comprehensive analysis of SEMA3D variants in the Asian ancestry.

Efficacy of Sox10 Promoter Methylation in the Diagnosis of Intestinal Neuronal Dysplasia From the Peripheral Blood

OBJECTIVES

Intestinal neuronal dysplasia (IND) is a common malformation of the enteric nervous system. Diagnosis requires a full-thickness colonic specimen and an experienced pathologist, emphasizing the need for noninvasive analytical methods. Recently, the methylation level of the Sox10 promoter has been found to be critical for enteric nervous system development. However, whether it can be used for diagnostic purposes in IND is unclear.

METHODS

Blood and colon specimens were collected from 32 patients with IND, 60 patients with Hirschsprung disease (HD), and 60 controls. Sox10 promoter methylation in the blood and the Sox10 expression level in the colon were determined, and their correlation was analyzed. The diagnostic efficacy of blood Sox10 promoter methylation was analyzed by receiver operating characteristic curve.

RESULTS

The blood level of Sox10 promoter methylation at the 32nd locus was 100% (90%-100%; 95% confidence interval [CI], 92.29%-96.37%) in control, 90% (80%-90%; 95% CI, 82.84%-87.83%) in HD, and 60% (50%-80%; 95% CI, 57.12%-69.76%) in IND specimens. Sox10 promoter methylation in the peripheral blood was negatively correlated with Sox10 expression in the colon, which was low in control, moderate in HD, and high in IND specimens (r = -0.89). The area under the curve of Sox10 promoter methylation in the diagnosis of IND was 0.94 (95% CI, 0.874-1.000, P = 0.000), with a cutoff value of 85% (sensitivity, 90.6%; specificity, 95.0%). By applying a cutoff value of 65%, promoter methylation was more indicative of IND than HD.

DISCUSSION

The analysis of Sox10 promoter methylation in the peripheral blood can be used as a noninvasive method for IND diagnosis.

"Too much guts and not enough brains": (epi)genetic mechanisms and future therapies of Hirschsprung disease - a review

Hirschsprung disease is a neurocristopathy, characterized by aganglionosis in the distal bowel. It is caused by failure of the enteric nervous system progenitors to migrate, proliferate, and differentiate in the gut. Development of an enteric nervous system is a tightly regulated process. Both the neural crest cells and the surrounding environment are regulated by different genes, signaling pathways, and morphogens. For this process to be successful, the timing of gene expression is crucial. Hence, alterations in expression of genes specific for the enteric nervous system may contribute to the pathogenesis of Hirschsprung’s disease. Several epigenetic mechanisms contribute to regulate gene expression, such as modifications of DNA and RNA, histone modifications, and microRNAs. Here, we review the current knowledge of epigenetic and epitranscriptomic regulation in the development of the enteric nervous system and its potential significance for the pathogenesis of Hirschsprung’s disease. We also discuss possible future therapies and how targeting epigenetic and epitranscriptomic mechanisms may open new avenues for novel treatment.

Epigenetic Mechanisms in Hirschsprung Disease

Hirschsprung disease (HSCR, OMIM 142623) is due to a failure of enteric precursor cells derived from neural crest (EPCs) to proliferate, migrate, survive or differentiate during Enteric Nervous System (ENS) formation. This is a complex process which requires a strict regulation that results in an ENS specific gene expression pattern. Alterations at this level lead to the onset of neurocristopathies such as HSCR. Gene expression is regulated by different mechanisms, such as DNA modifications (at the epigenetic level), transcriptional mechanisms (transcription factors, silencers, enhancers and repressors), postranscriptional mechanisms (3′UTR and ncRNA) and regulation of translation. All these mechanisms are finally implicated in cell signaling to determine the migration, proliferation, differentiation and survival processes for correct ENS development. In this review, we have performed an overview on the role of epigenetic mechanisms at transcriptional and posttranscriptional levels on these cellular events in neural crest cells (NCCs), ENS development, as well as in HSCR.

News from the endothelin-3/EDNRB signaling pathway: Role during enteric nervous system development and involvement in neural crest-associated disorders

The endothelin system is a vertebrate-specific innovation with important roles in regulating the cardiovascular system and renal and pulmonary processes, as well as the development of the vertebrate-specific neural crest cell population and its derivatives. This system is comprised of three structurally similar 21-amino acid peptides that bind and activate two G-protein coupled receptors. In 1994, knockouts of the Edn3 and Ednrb genes revealed their crucial function during development of the enteric nervous system and melanocytes, two neural-crest derivatives. Since then, human and mouse genetics, combined with cellular and developmental studies, have helped to unravel the role of this signaling pathway during development and adulthood. In this review, we will summarize the known functions of the EDN3/EDNRB pathway during neural crest development, with a specific focus on recent scientific advances, and the enteric nervous system in normal and pathological conditions.

Gli family zinc finger 1 is associated with endothelin receptor type B in Hirschsprung disease

Hirschsprung disease (HSCR) is a newborn colorectal disease characterized by an absence of ganglia in the distal gut. Hedgehog (Hh) and endothelin signaling serve important roles in gastrointestinal tract formation. Alterations in the signaling pathways disrupt the development of enteric neural crest cells (ENCCs). It is not known whether there is any coordination between these pathways in the pathogenesis of HSCR. In the present study, tissue samples from 35 patients with HSCR, including stenotic aganglionosis gut and normal ganglionic gut, were obtained. The expression of Gli family zinc finger 1 (Gli1) and endothelin receptor type B (EDNRB) was determined using reverse transcription-quantitative polymerase chain reaction, immunohistochemistry and western blotting. In addition, the SK-N-SH cell line was used to investigate the association between Hh signaling and the expression of EDNRB. The results revealed aberrant expression of Gli1 in the aganglionic segments, as well as decreased expression of Gli1 in tissues from 7 patients with HSCR exhibited, whereas tissues from 9 patients with HSCR exhibited increased Gli1 expression compared with the expression in the normal tissues. There was a negative association between EDNRB expression and Gli1 expression in the same sample. Knockdown of Gli1 by small interfering RNA and inhibition of Hh signaling by Vismodegib in SK-N-SH cells increased EDNRB expression. By contrast, upregulation of Gli1 expression by plasmids and activation of Hh signaling by Purmorphamine decreased EDNRB expression. Furthermore, premature enteric ganglia were observed in 4 patients with HSCR with decreased Gli1 expression. Thus, the results of the present study suggest that altered Gli1 expression negatively regulates EDNRB expression in patients with HSCR. The increased expression of EDNRB induced by decreased Gli1 expression may represent a novel mechanism in HSCR.

Downregulation of microRNA-483-5p Promotes Cell Proliferation and Invasion by Targeting GFRA4 in Hirschsprung's Disease

Recent studies have suggested the critical roles of miRNAs for disease progression. miRNA-483-5p (miR-483-5p) was previously found to have a relationship with tumor cell behavior, but its biological function in Hirschsprung's disease (HSCR) remains undefined. Thus, we explored the role of miR-483-5p in the pathogenesis of HSCR. Histological changes of colonic tissues were evaluated by hematoxylin and eosin (HE) staining. Quantitative real-time PCR and western blotting were used to determine relative expression levels of miRNA, mRNA, and proteins in 20 HSCR patients and 20 normal colon tissues. In this study, we found that miR-483-5p expression in HSCR tissues was significantly increased and their downregulation promoted cell proliferation, cell cycle progression and invasion and inhibited cell apoptosis in human 293T and SH-SY5Y cell lines by the CCK-8, flow cytometry, and Transwell assay. GNDF family receptor alpha 4 (GFRA4) was confirmed as a downstream target of miR-483-5p by dual-luciferase reporter gene assay and inversely correlated with miR-483-5p expression in cell lines. Taken together, miR-483-5p may play a crucial role in the pathogenesis of HSCR by targeting GFRA4.

Epigenetics in ENS development and Hirschsprung disease

Hirschsprung disease (HSCR, OMIM 142623) is a neurocristopathy caused by a failure of the enteric nervous system (ENS) progenitors derived from neural crest cells (NCCs), to migrate, proliferate, differentiate or survive to and within the gastrointestinal tract, resulting in aganglionosis in the distal colon. The formation of the ENS is a complex process, which is regulated by a large range of molecules and signalling pathways involving both the NCCs and the intestinal environment. This tightly regulated process needs correct regulation of the expression of ENS specific genes. Alterations in the expression of these genes can have dramatic consequences. Several mechanisms that control the expression of genes have been described, such as DNA modification (epigenetic mechanisms), regulation of transcription (transcription factor, enhancers, repressors and silencers), post-transcriptional regulation (3'UTR and miRNAs) and regulation of translation. In this review, we focus on the epigenetic DNA modifications that have been described so far in the context of the ENS development. Moreover we describe the changes that are found in relation to the onset of HSCR.

DNA methylation is critical for tooth agenesis: implications for sporadic non-syndromic anodontia and hypodontia

Hypodontia is caused by interactions among genetic, epigenetic, and environmental factors during tooth development, but the actual mechanism is unknown. DNA methylation now appears to play a significant role in abnormal developments, flawed phenotypes, and acquired diseases. Methylated DNA immunoprecipitation (MeDIP) has been developed as a new method of scanning large-scale DNA-methylation profiles within particular regions or in the entire genome. Here, we performed a genome-wide scan of paired DNA samples obtained from 4 patients lacking two mandibular incisors and 4 healthy controls with normal dentition. We scanned another female with non-syndromic anodontia and her younger brother with the same gene mutations of the PAX9,MSX1,AXIN2 and EDA, but without developmental abnormalities in the dentition. Results showed significant differences in the methylation level of the whole genome between the hypodontia and the normal groups. Nine genes were spotted, some of which have not been associated with dental development; these genes were related mainly to the development of cartilage, bone, teeth, and neural transduction, which implied a potential gene cascade network in hypodontia at the methylation level. This pilot study reveals the critical role of DNA methylation in hypodontia and might provide insights into developmental biology and the pathobiology of acquired diseases.

Down-regulation of miR-206 is associated with Hirschsprung disease and suppresses cell migration and proliferation in cell models

Hirschsprung disease (HSCR) is a well-known congenital digestive disease that originates due to the developmental disorder of neural crest cells. MiR-206 is kown to have a relationship with digestive malfunctions. Therefore, we investigated whether or not miR-206 was involved in the pathogenesis of HSCR. qRT-PCR and Western blot assays were used to detect the expression levels of miRNA and mRNAs, and proteins in case and control tissue samples and two cell lines (293T and SH-SY5Y). The functions of miR-206 in vitro were measured by transwell assay, CCK8 assay and flow cytometry. Finally, we conducted dual-luciferase reporter assay to verify the connections between miR-206 and the target mRNA SDPR. Down-regulation of miR-206 was found in HSCR case tissue samples compared with controls, which was validated to be connected with the increased level of mRNA and protein of SDPR by qRT-PCR and dual-luciferase reporter assay. Moreover, miR-206 suppressed the cell migration and proliferation and silencing of SDPR could rescue the extent of the suppressing effects by miR-206 inhibitor. The findings suggest that miR-206 may play a significant role in the pathogenesis of HSCR, as well as inhibiting the cell migration and proliferation by targeting SDPR in disease models.

Validation of endothelin B receptor antibodies reveals two distinct receptor-related bands on Western blot

Antibodies are important tools for the study of protein expression but are often used without full validation. In this study, we used Western blots to characterize antibodies targeted to the N or C terminal (NT or CT, respectively) and the second or third intracellular loop (IL2 or IL3, respectively) of the endothelin B receptor (ETB). The IL2-targeted antibody accurately detected endogenous ETB expression in rat brain and cultured rat astrocytes by labeling a 50-kDa band, the expected weight of full-length ETB. However, this antibody failed to detect transfected ETB in HEK293 cultures. In contrast, the NT-targeted antibody accurately detected endogenous ETB in rat astrocyte cultures and transfected ETB in HEK293 cultures by labeling a 37-kDa band but failed to detect endogenous ETB in rat brain. Bands detected by the CT- or IL3-targeted antibody were found to be unrelated to ETB. Our findings show that functional ETB can be detected at 50 or 37kDa on Western blot, with drastic differences in antibody affinity for these bands. The 37-kDa band likely reflects ETB processing, which appears to be dependent on cell type and/or culture condition.

MiR-195 affects cell migration and cell proliferation by down-regulating DIEXF in Hirschsprung's disease

Background

Hirschsprung’s disease (HSCR) is the most common congenital gut motility disorder. We aimed to investigate the roles of miR-195 in the pathogenesis of HSCR.

Methods

In this study, we measured the expression levels of miRNA, mRNA, and protein in colon tissues from 78 patients with HSCR and 66 controls without HSCR. Transwell, Cell Counting Kit-8 (CCK-8) and flow cytometry assay were employed to detect the function role of miR-195 in vitro.

Results

Our results showed that expression levels of miR-195 from patients with HSCR were significantly higher than control group; along with aberrant lower expression levels of digestive-organ expansion factor (DIEXF) were tested. Increased level of miR-195 could suppress the level of DIEXF in cell, which induced the impairment of cell migration and proliferation.

Conclusions

Aberrant expression of miR-195 may involved in the pathogenesis of HSCR by down-regulated the level of DIEXF.

Hypermethylation of EDNRB promoter contributes to the risk of colorectal cancer

OBJECTIVE

Colorectal cancer (CRC) is one of the most common digestive malignancies in the world. EDNRB is a new candidate tumor suppressor gene which is often down-regulated or even silenced by promoter hypermethylation in various human cancers. However, the function of EDNRB gene in CRC remains unknown. In this study, we examined the expression and DNA methylation of EDNRB in CRC tissues.

METHODS

A total of 42 paired CRC and adjacent normal tissue samples were used to determine mRNA levels and DNA methylation status of EDNRB gene by qRT-PCR and methylation-specific PCR (MSP), respectively.

RESULTS

Our study showed that EDNRB promoter hypermethylation was more frequently in CRC tissues than in the normal tissues (92.86 versus 59.52, p = 0.001). Consequently, significantly lower level of EDNRB mRNA was found in CRC tumor samples than in normal samples (0.31 ± 0.91 versus 0.70 ± 1.18, p = 0.032).

CONCLUSIONS

Our results suggested that EDNRB promoter hypermethylation might downregulate its gene expression in CRC, and thus played an important role in the development of CRC.

THE VIRTUAL SLIDE

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7420980471113303.