Long non-coding RNA LOC100507600 functions as a competitive endogenous RNA to regulate BMI1 expression by sponging miR128-1-3p in 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.

Bioinformatics Prediction for Network-Based Integrative Multi-Omics Expression Data Analysis in Hirschsprung Disease

Hirschsprung's disease (HSCR) is a rare developmental disorder in which enteric ganglia are missing along a portion of the intestine. HSCR has a complex inheritance, with RET as the major disease-causing gene. However, the pathogenesis of HSCR is still not completely understood. Therefore, we applied a computational approach based on multi-omics network characterization and clustering analysis for HSCR-related gene/miRNA identification and biomarker discovery. Protein-protein interaction (PPI) and miRNA-target interaction (MTI) networks were analyzed by DPClusO and BiClusO, respectively, and finally, the biomarker potential of miRNAs was computationally screened by miRNA-BD. In this study, a total of 55 significant gene-disease modules were identified, allowing us to propose 178 new HSCR candidate genes and two biological pathways. Moreover, we identified 12 key miRNAs with biomarker potential among 137 predicted HSCR-associated miRNAs. Functional analysis of new candidates showed that enrichment terms related to gene ontology (GO) and pathways were associated with HSCR. In conclusion, this approach has allowed us to decipher new clues of the etiopathogenesis of HSCR, although molecular experiments are further needed for clinical validations.

Sequencing Reveals miRNAs Enriched in the Developing Mouse Enteric Nervous System

The enteric nervous system (ENS) is an essential network of neurons and glia in the bowel wall. Defects in ENS development can result in Hirschsprung disease (HSCR), a life-threatening condition characterized by severe constipation, abdominal distention, bilious vomiting, and failure to thrive. A growing body of literature connects HSCR to alterations in miRNA expression, but there are limited data on the normal miRNA landscape in the developing ENS. We sequenced small RNAs (smRNA-seq) and messenger RNAs (mRNA-seq) from ENS precursor cells of mid-gestation Ednrb-EGFP mice and compared them to aggregated RNA from all other cells in the developing bowel. Our smRNA-seq results identified 73 miRNAs that were significantly enriched and highly expressed in the developing ENS, with miR-9, miR-27b, miR-124, miR-137, and miR-488 as our top 5 miRNAs that are conserved in humans. However, contrary to prior reports, our follow-up analyses of miR-137 showed that loss of Mir137 in Nestin-cre, Wnt1-cre, Sox10-cre, or Baf53b-cre lineage cells had no effect on mouse survival or ENS development. Our data provide important context for future studies of miRNAs in HSCR and other ENS diseases and highlight open questions about facility-specific factors in development.

LINC01579-204 involved in the development of Hirschsprung's disease maybe by regulating the expression of miR-203a-3p and NEFL

BACKGROUND

Hirschsprung's disease (HD) is a rare congenital digestive tract malformation in children. Roles of long non-coding RNAs (lncRNAs) are highlighted in various human diseases. However, knowledge on lncRNAs in HD is still limited.

METHODS

The profile of lncRNAs in 8 pairs of normal and stenosed intestinal tissue of HD patients were obtained using microarray analysis. Base on bioinformatics analysis, the level of selected LINC01579-204, NEFL and miR-203a-3p was detected by qRT-PCR in 36 pairs of normal and stenosed intestinal tissue of HD patients. Then the predictive accuracy of LINC01579-204, miR-203a-3p and NEFL level to evaluate the progression of HD patients was analyzed with receiver operating characteristic curve (ROC).

RESULTS

A total of 90 differentially expressed lncRNAs were detected in normal and stenosed intestinal tissue of HD patients (|fold change| ≥ 1.5, p < 0.05). The level of LINC01579-204 and NEFL decreased and miR-203a-3p increased significantly in 36 pairs of stenosed intestinal tissue of HD patients compared to the control. A notable positive correlation was identified between LINC01579-204 and NEFL (r = 0.9681, p < 0.0001). Areas under the ROC curve of the LINC01579-204, miR-203a-3p and NEFL signature were 0.715, 0.777 and 0.829, respectively.

CONCLUSIONS

LINC01579-204, miR-203a-3p, and NEFL are predicted to play important roles in the progression of HD. LINC01579-204, miR-203a-3p and NEFL had a significant overall predictive ability to identify progression of HD patients. The novel experimental and bioinformatic results achieved in this study may provide new insights into the molecular of HD.

Silencing of purinergic receptor P2Y2 inhibited enteric neural crest cell proliferation, invasion and migration via suppressing ERK signaling pathway in Hirschsprung disease

The current study aimed to explore the effect and underlying mechanism of the purinergic receptor P2Y2 in regulating the loss of intestinal neurons and the intestinal neural crest in Hirschsprung's disease (HSCR). Western blotting was used to assess the expression levels of P2Y2 in colon tissues. An in vivo HSCR mouse model was established following treatment with benzalkonium chloride (BAC). We overexpressed or silenced P2Y2 in SH-SY5Y cells, and cell proliferation, migration, and invasion were subsequently investigated by CCK-8, wound healing, and transwell assays, respectively. Additionally, we implemented a xenograft model to assess the impact of P2Y2 on tumor growth as well as the expression of extracellular signal-regulated kinase (ERK). The results showed that the expression of P2Y2 protein in the colon tissues of patients with HSCR was lower than that in the normal colon tissues. P2Y2 expression is downregulated in the colon tissues of mice with HSCR. Additionally, P2Y2 silencing inhibited SH-SY5Y cell proliferation, invasion, and migration. Furthermore, adenosine 5'-triphosphate (ATP, a strong agonist of P2Y2)-induced P2Y2 overexpression enhanced the proliferation, invasion, and migration of SH-SY5Y cells. Immunofluorescence staining and western blot analysis revealed that P2Y2 silencing downregulated phosphorylated (p)-ERK in SH-SY5Y cells. In addition, treatment with PD98059, a p-ERK inhibitor, reversed the effects of ATP on SH-SY5Y cell proliferation, invasion, and migration. Finally, we demonstrated that P2Y2 silencing suppressed tumor growth and decreased p-ERK expression. Overall, the results of the present study suggest that P2Y2 plays an important role in HSCR pathogenesis. P2Y2 silencing inhibited the proliferation, invasion, and migration of nerve cells by suppressing the ERK signaling pathway. P2Y2 silencing could be considered an innovative and possible target for treating HSCR.

Intrauterine exposure to oxidative stress induces caspase-1-dependent enteric nerve cell pyroptosis

PURPOSE

This study determined whether oxidative stress causes the developmental abnormalities of the enteric nervous system during the embryonic period.

METHODS

Using the test results of tissue specimens of children with Hirschsprung disease (HSCR), we established a pregnant rat model of oxidative stress and a cellular oxidative stress model to conduct related molecular, cellular, and histopathological experiments for exploration and validation.

RESULTS

The results of the quantitative real-time polymerase chain reaction assay indicated overexpression of pyroptosis markers (NLRP3, ASC, and caspase-1) in HSCR lesions and newborn pups in the oxidative stress group (treated with D-galactose). The expression of cathepsin D was significantly decreased in intestinal tissues of newborn pups in the oxidative stress group compared to the control group. Reactive oxygen species scavengers (N-acetyl-cysteine, NAC), the caspase-1 inhibitor (VX-765), and the NLRP3 siRNA could reverse the release of LDH, decrease the number of propidium iodide stained cells, and reduce the percentage of TUNEL/caspase-3 double-positive cells in the H₂O₂-treated group.

CONCLUSION

Oxidative stress can induce the death of enteric nerve cells by activating caspase-1-dependent pyroptosis through NLRP3 inflammasomes, which may contribute to abnormal enteric nervous system development.

Aberrant expression of LINC00346 regulates cell migration and proliferation via competitively binding to miRNA-148a-3p/Dnmt1 in Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a common birth defect caused by dysplasia of neural crest cells in the gut. Long noncoding RNAs (lncRNAs) play an important role in cellular processes, including development and disease. Despite the known engagement of LINC00346 in several human diseases, its biological function in HSCR remains unknown.

METHODS

The relative expression levels of LINC00346, miR-148a-3p and Dnmt1 in HSCR colon tissues were detected by quantitative real-time PCR. Western blot assays were conducted to investigate the Dnmt1 protein expression level. Knockdown of LINC00346 and overexpression of miR-148a-3p in SH-SY5Y and SK-N-BE(2) cell lines was conducted. Cell proliferation and migration were detected by cell counting Kit-8 assays, 5-ethynyl-2'-deoxyuridine assays and transwell assays. Cell apoptosis was verified by flow cytometric analysis. Furthermore, the competing endogenous RNA (ceRNA) activity of LINC00346 on miR-148a-5p was investigated via bioinformatics analysis and luciferase reporter assays.

RESULT

Downregulation of LINC00346 and Dnmt1 was detected in HSCR tissues. Knockdown of LINC00346 and overexpression of miR-148a-3p in SK-N-BE(2) and SH-SY5Y cells inhibited cell migration and proliferation and promoted apoptosis. Moreover, the miR-148a-3p inhibitor rescued the downregulation of Dnmt1 in LINC00346 knockdown cell lines, which was evidence of the ceRNA regulatory mechanism of Dnmt1 by LINC00346.

CONCLUSIONS

LINC00346 was downregulated in HSCR colon tissues and acted as a ceRNA to regulate the expression of Dnmt1 in vitro. Together, these findings indicate that LINC00346 could affect the occurrence of HSCR by participating in the development of enteric neural crest cells.

LncRNA-RMST Functions as a Transcriptional Co-regulator of SOX2 to Regulate miR-1251 in the Progression of Hirschsprung's Disease

Hirschsprung's disease (HSCR) is a congenital disorder characterized by the absence of enteric neural crest cells (ENCCs). LncRNA rhabdomyosarcoma 2-associated transcript (RMST) is essential for the growth and development of neuron. This study aimed to reveal the role of RMST in the pathogenesis of HSCR. The expression level of RMST, miR-1251, SOX2, and AHNAK was evaluated with qRT-PCR or western blot. CCK-8 and transwell assays were applied to detect cell proliferation and migration. CHIP and RIP assays were applied to determine the combination relationship between SOX2 and promoter region of miR-1251 or RMST and SOX2, respectively. Dual-luciferase reporter assay was performed to confirm miR-1251 targeted AHNAK. As results have shown, RMST was downregulated in the aganglionic colon of HSCR patients. The knockdown of RMST attenuated cell proliferation and migration significantly. MiR-1251, the intronic miRNA of RMST, was also low expressed in HSCR, but RMST did not alter the expression of miR-1251 directly. Furthermore, SOX2 was found to regulate the expression of miR-1251 via binding to the promoter region of miR-1251, and RMST strengthened this function by interacting with SOX2. Moreover, AHNAK was the target gene of miR-1251, which was co-regulated by RMST and SOX2. In conclusion, our study demonstrated that RMST functioned as a transcriptional co-regulator of SOX2 to regulate miR-1251 and resulted in the upregulation of AHNAK, leading to the occurrence of HSCR. The novel RMST/SOX2/miR-1251/AHNAK axis provided potential targets for the diagnosis and treatment of HSCR during embryonic stage.

miR-25-3p promotes proliferation and inhibits autophagy of renal cells in polycystic kidney mice by regulating ATG14-Beclin 1

MicroRNAs are involved in the regulation of the autophagy and proliferation in several diseases. This study aims to verify the role of miR-25-3p in the proliferation and autophagy of renal cells in polycystic kidney disease (PKD). We found that kidney to body weight and blood urea content were increased in PKD mice. Cystic dilations were increased in kidney tissue from PKD mice, and autophagy-related protein ULK1 and the ratio of LC3-II/LC3-I were decreased, indicating autophagy was inhibited in PKD mice. In addition, miR-25-3p was upregulated in PKD mice, and inhibition of miR-25-3p decreased cystic dilations in kidney tissues, increased ULK1 expression and the ratio of LC3-II/LC3-I, indicating inhibition of miR-25-3p enhanced the autophagy in PKD. Besides, inhibition of miR-25-3p suppressed the proliferation of renal cells and downregulated E2F-1 and PCNA expressions. Importantly, miR-25-3p targetedly suppressed ATG14 expression in PKD cells. Finally, silencing ATG14 abolished the inhibition effect of miR-25-3p inhibitor on renal cell proliferation, and reversed the inhibition effect of miR-25-3p inhibitor on E2F-1 and PCNA expressions in in vitro and in vivo experiments, which suggested that ATG14 was involved in the regulation of miR-25-3p-mediated kidney cell proliferation. Therefore, inhibition of miR-25-3p promoted cell autophagy and suppressed cell proliferation in PKD mice through regulating ATG14.

LncRNA DRAIC regulates cell proliferation and migration by affecting the miR-34a-5p/ITGA6 signal axis in Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a common defect in newborns, and studies have revealed that long non-coding RNA (lncRNA) is involved in the progression of HSCR. This research study aims to investigate the mechanism of downregulated RNA in cancer (DRAIC) on cell proliferation and migration in HSCR.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the expression of DRAIC in HSCR bowel stenosis tissues and normal colon tissues. Cell-counting kit-8 (CCK-8) and Transwell assays were employed to explore whether cellular functions change after overexpression or knockdown of the DRAIC in SH-SY5Y cells and human 293T cells. Protein expression levels were determined by Western blot analysis. RNA pull-down and dual-luciferase reporter assays were used to confirm the competitive relationship of DRAIC and integrin subunit alpha 6 (ITGA6) through their association with miR-34a-5p.

RESULTS

The lncRNA DRAIC was significantly increased in colon tissue from HSCR patients. The overexpression of DRAIC inhibited SH-SY5Y cell and human 293T cell proliferation and migration. Knockdown of DRAIC, however, promoted cell proliferation and migration. The RNA pull-down and dual-luciferase reporter assays have proven the competitive relationship between DRAIC and ITGA6 through their association with miR-34a-5p. Further rescue experiments have confirmed that DRAIC regulates cell proliferation and migration by affecting the miR-34a-5p/ITGA6 signal axis in HSCR.

CONCLUSION

DRAIC promoted cell proliferation and migration by regulating the miR-34a-5p/ITGA6 signal axis in HSCR.

Identification of New Potential LncRNA Biomarkers in Hirschsprung Disease

Hirschsprung disease (HSCR) is a neurocristopathy defined by intestinal aganglionosis due to alterations during the development of the Enteric Nervous System (ENS). A wide spectrum of molecules involved in different signaling pathways and mechanisms have been described in HSCR onset. Among them, epigenetic mechanisms are gaining increasing relevance. In an effort to better understand the epigenetic basis of HSCR, we have performed an analysis for the identification of long non-coding RNAs (lncRNAs) by qRT-PCR in enteric precursor cells (EPCs) from controls and HSCR patients. We aimed to test the presence of a set lncRNAs among 84 lncRNAs in human EPCs, which were previously related with crucial cellular processes for ENS development, as well as to identify the possible differences between HSCR patients and controls. As a result, we have determined a set of lncRNAs with positive expression in human EPCs that were screened for mutations using the exome data from our cohort of HSCR patients to identify possible variants related to this pathology. Interestingly, we identified three lncRNAs with different levels of their transcripts (SOCS2-AS, MEG3 and NEAT1) between HSCR patients and controls. We propose such lncRNAs as possible regulatory elements implicated in the onset of HSCR as well as potential biomarkers of this pathology.

The Long Non-coding RNA LINC01705 Regulates the Development of Breast Cancer by Sponging miR-186-5p to Mediate TPR Expression as a Competitive Endogenous RNA

Long non-coding RNAs (lncRNAs) may be a regulatory factor of tumorigenesis. However, it is unclear what its biomechanisms are in breast cancer. In this study, different lncRNAs were detected in breast cancer through microarray analysis (GSE119233) and LINC01705 was selected for further study. qRT-PCR was then utilized for the detection of LINC01705 expression in breast cancer cells. A transwell assay, flow cytometry, 5-ethynyl-2'-deoxyuridine (EdU), a cell counting Kit-8 (CCK-8), and a wound-healing assay were performed to determine cell migration, invasion, apoptosis, and proliferation in breast cancer, respectively. For the identification of potential targets of LINC01705, dual-luciferase reporter gene and bioinformatics assays were conducted. Moreover, for the clarification of their interaction and roles in the regulation of the occurrence of breast cancer, Western blotting and RIP assays were conducted. Our findings revealed high LINC01705 expression in breast cancer tissues relative to adjacent non-cancerous tissues (n = 40, P < 0.001). Overexpression of LINC01705 notably enhanced cell migration and proliferation in breast cancer. In addition, LINC01705 positively regulated the translocated promoter region, nuclear basket protein (TPR) through competition with miR-186-5p. In conclusion, our results suggest that LINC01705 is implicated in the progression of breast cancer via competitively binding to miR-186-5p as a competing endogenous RNA (ceRNA), thereby regulating TPR expression.

MicroRNA-128-3p Enhances the Chemosensitivity of Temozolomide in Glioblastoma by Targeting c-Met and EMT

Temozolomide is a first line anti-tumor drug used for the treatment of patients with Glioblastoma multiforme (GBM). However, the drug resistance to temozolomide limits its clinical application. Therefore, novel strategies to overcome chemoresistance are desperately needed for improved treatment of human GBM. Recent studies have demonstrated that miRNAs are closely related to resistance to cancer chemotherapy. This study aimed to further validate the biological role of miR-128-3p and to investigate whether miR-128-3p can enhance the chemosensitivity of glioblastoma to temozolomide (TMZ) and the underlying mechanisms. The effects of miR-128-3p and TMZ on the proliferation of glioblastoma cells were investigated by cell counting kit-8 (cck8). Transwell and intracerebral invasion assays were applied to determine the effects of the combination of miR-128-3p and TMZ on the invasion and migration of glioblastoma in vitro and in vivo. Flow cytometry was used to detect apoptosis in each group, and immunofluorescence was used to determine the expression levels of EMT-related proteins. RT-PCR and Western-blot were applied to detect EMT-transformed proteins (c-Met, PDGFRα, Notch1, and Slug) and EMT phenotype-associated proteins (Vim, CD44, and E-cadherin) at both mRNA and protein levels. Based on the microRNA.org database, we predicted the target genes of miR-128-3p. The target-relationship between miR-128-3p and c-Met and PDGFRα was verified by dual luciferase reporter gene. The tumor volume, weight and the expression levels of the proteins described above were measured in subcutaneously transplanted tumor model in nude mice. We found that the expression of miR-128-3p was down-regulated in glioblastoma tissue samples and cell lines. miR-128-3p suppressed the proliferation, migration, and invasion of GBM both in vitro and in vivo; miR-128-3p enhanced the therapeutic effect of TMZ via inhibition of proliferation, invasion and migration of glioblastoma cells and induction of apoptosis. Overexpression of miR-128-3p down-regulated the expression levels of EMT-transformed proteins (c-Met, PDGFRα, Notch1 and Slug) to enhance the effect of TMZ. In addition, we found that miR-128-3p targeted and bound c-Met. More importantly, the upregulation of c‐Met significantly prompted U87 and U251 cell proliferation. This effect could be abolished when c‐Met was silenced. The investigation in tumor bearing nude mice showed that miR-128-3p in combination with TMZ reduced tumor volume and the invasion extent, and increased the sensitivity of glioblastoma to TMZ. miR-128-3p is capable of enhancing the sensitivity of glioblastoma to TMZ through regulating c-Met/EMT.

Negative Association Between lncRNA HOTTIP rs3807598 C>G and Hirschsprung Disease

Background

Hirschsprung disease (HSCR) is a congenital disease that arises from defective intestinal neural system. LncRNA HOTTIP is a critical gene in various diseases, including HSCR. No epidemiological studies have explored the correlation between lncRNA HOTTIP single nucleotide polymorphisms (SNPs) and HSCR risk. We here lead as a pioneer to explore whether SNPs in lncRNA HOTTIP impact the risk of HSCR and HSCR subtypes in an unrelated Chinese population.

Methods

We used the TaqMan method to genotype rs3807598 C>G of the lncRNA HOTTIP gene using 1470 HSCR cases and 1473 healthy controls. Of them, 1441 cases and 1434 controls were successfully genotyped. We adopted odds ratios (ORs) and 95% confidence intervals (CIs) to quantify the relationship.

Results

We got an unexpected outcome that lncRNA HOTTIP SNP rs3807598 C>G could not modify the risk of HSCR (CG vs. CC: adjusted OR=0.89, 95% CI=0.74–1.07; GG vs. CC: adjusted OR=1.10, 95% CI=0.89–1.37; GG/CG vs CC: adjusted OR=0.95, 95% CI=0.80–1.13; and GG vs. CC/CG: adjusted OR=1.19, 95% CI=0.99–1.43). What’s more, risk effect of lncRNA HOTTIP rs3807598 C>G is still not obvious in stratification analysis by HSCR subtype.

Conclusion

Our studies did not provide statistical evidence of a correlation between lncRNA HOTTIP SNP rs3807598 C>G and susceptibility of HSCR in the Chinese population that is being studied. Further validation study with a larger sample size covering multi-ethnic groups is warranted.

Long noncoding RNA LINC01278 favors the progression of osteosarcoma via modulating miR-133a-3p/PTHR1 signaling

As one of the most aggressive malignancies, osteosarcoma has high risks of death. Although long noncoding RNAs (lncRNAs) may promote the osteosarcoma progression as verified, the potential molecular mechanism of lncRNAs in osteosarcoma remains unknown. Herein, we analyzed lncRNA microarray of osteosarcoma and selected LINC01278 as the study object. Then, we found that the expression of LINC01278 tested by quantitative reverse-transcription polymerase chain reaction was enhanced in tumor tissues compared with the para-carcinoma tissues and related to clinical stage, distant metastasis in osteosarcoma. In addition, the clinical outcomes were poor in osteosarcoma patients with high LINC01278 level. Moreover, LINC01278 promoted proliferation and restrained apoptosis in osteosarcoma cells. Afterward, mechanistic studies turned out that LINC01278 was a competing endogenous RNA of parathyroid hormone type 1 receptor (PTHR1) in osteosarcoma by sponging miR-133a-3p, which was considered as a tumor inhibitor in osteosarcoma. Furthermore, PTHR1 downregulation restored the impacts of inhibited miR-133a-3p on the processes in osteosarcoma cells. Our findings clarified that the carcinogenic effect of LINC01278 in osteosarcoma was mediated through miR-133a-3p/PTHR1 signaling, creating a novel insight into good targets for the therapy and prognosis of osteosarcoma.

Long noncoding RNA H19 regulates HIF-1α/AXL signaling through inhibiting miR-20b-5p in endometrial cancer

In a variety of cancers, long non-coding RNAs (lncRNAs) were believed to play important roles. Nevertheless, H19's possible molecular mechanism related to miR-20b-5p has not yet been explored in endometrial cancer. Differential lncRNAs in endometrial cancer were identified based on microarray analysis (GSE23339). In this research, in the first place, H19 expression was detected to be increased but miR-20b-5p to be decreased in endometrial cancer tissues and cells. Besides, H19 expression displayed a negative relationship to miR-20b-5p expression in endometrial cancer tissues. According to gain- and loss-of-function experiments of H19, like a ceRNA, H19 elevated AXL level and HIF-1α expression so as to stimulate the migration, proliferation and EMT process of endometrial cancer. Additionally, the knockdown of H19 slowed down tumor growth, promoted apoptosis and upregulated miR-20b-5p expression but lowered the expressions of HIF-1α, PCNA and AXL in vivo. Furthermore, H19 was also verified to stimulate the activity of endometrial cancer with AXL inhibitor BGB324 in vitro and in vivo. To sum up, H19 accelerates the tumor formation of endometrial cancer through the miR-20b-5p/AXL/HIF-1α signaling pathway, thereby providing a novel target for diagnosing and treating endometrial cancer.

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.

Long non-coding RNA FAL1 functions as a ceRNA to antagonize the effect of miR-637 on the down-regulation of AKT1 in Hirschsprung's disease

OBJECTIVES

Emerged evidence demonstrates that long non-coding RNAs (lncRNAs) may play quintessential regulatory roles in the cellular processes, tumourigenesis and the development of disease. Though focally amplified lncRNA on chromosome 1 (FAL1) has been identified to have crucial functions in many diseases, its biological mechanism in the development of Hirschsprung's disease (HSCR) still remains unknown.

MATERIALS AND METHODS

The expression levels of FAL1 in HSCR aganglionic tissues and matched normal specimens were detected by quantitative real-time PCR (qRT-PCR). Cell proliferation and migration were detected by Cell Counting Kit-8 (CCK-8) assay, Ethynyl-deoxyuridine (EdU) assay and transwell assay relatively. Cell cycle and apoptosis were assessed using flow cytometer analysis. Moreover, the novel targets of FAL1 were confirmed with the help of bioinformatics analysis and dual-luciferase reporter assay. Western blot assay as well as RNA immunoprecipitation (RIP) assay was conducted to investigate the potential mechanism.

RESULTS

FAL1 expression was markedly down-regulated in HSCR aganglionic tissues and decreased FAL1 expression was associated with the diagnosis of HSCR. Cell functional analyses indicated that FAL1 overexpressing notably promoted cell proliferation and migration, while down-regulation of FAL1 suppressed cell proliferation and migration. Additionally, Flow cytometry assay demonstrated that knockdown of FAL1 induced markedly cell cycle stalled in the G0/G1 phase. Furthermore, FAL1 could positively regulate AKT1 expression by competitively binding to miR-637.

CONCLUSIONS

These results illuminated that FAL1 may work as a ceRNA to modulate AKT1 expression via competitively binding to miR-637 in HSCR, suggesting that it may be clinically valuable as a biomarker of HSCR.

Down-regulation of circ-PRKCI inhibits cell migration and proliferation in Hirschsprung disease by suppressing the expression of miR-1324 target PLCB1

Circular RNAs (circRNAs) are a novel class of noncoding RNAs (ncRNAs), which have been shown to participate in intracellular RNA regulatory networks and play vital roles in many pathological processes. Recently, circular RNA_PRKCI (circ-PRKCI) has been reported to regulate cell proliferation, migration and invasion in several human cancers. Hirschsprung disease (HSCR) is a well-known congenital gut motility disorder which roots in the aberrance of cranial-caudal neural crest cell migration. In this study, we investigated whether circ-PRKCI may affect cell migration and proliferation in HSCR. Quantitative reverse transcription PCR (qRT-PCR) was performed to detect the expression of circ-PRKCI in 48 HSCR aganglionic tissues and 48 normal bowel tissues. Luciferase reporter assay and RNA immunoprecipitation (RIP) assay verified the direct interaction between miR-1324 and PLCB1 or circ-PRKCI. Cell counting Kit-8 (CCK-8) and Ethynyldeoxyuridine (EdU) assays were employed to appraise the effects of miR-1324 or circ-PRKCI on cell proliferative potential, while transwell was performed to detect the migration in vitro. We found that circ-PRKCI was significantly down-regulated in HSCR aganglionic tissues. Morever, knockdown of circ-PRKCI suppressed cell proliferation and migration in vitro. Mechanistically, we confirmed that circ-PRKCI functioned as a molecular sponge for miR-1324 to upregulate the expression of PLCB1. In conclusion, our present study revealed the important role of circ-PRKCI-miR-1324-PLCB1 regulatory network in HSCR, providing a novel insight for the pathogenesis of HSCR.