Negative feedback circuitry between MIR143HG and RBM24 in Hirschsprung 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.

Exploring the Spectrum of Long Non-Coding RNA CARMN in Physiological and Pathological Contexts

Cardiac mesoderm enhancer-associated non-coding RNA (CARMN), an evolutionarily conserved long non-coding RNA (lncRNA), serves as the host gene for the miR143/145 cluster. It plays a crucial role in cardiovascular cell differentiation and the maintenance of vascular smooth muscle cell (VSMC) homeostasis, which are vital for normal physiological processes. Specifically, CARMN is associated with the pathological progression of cardiovascular diseases such as atherosclerosis, abdominal aortic aneurysm, and chronic heart failure. Moreover, it acts as a tumor suppressor in various cancers, including hepatocellular carcinoma, bladder cancer, and breast cancer, highlighting its potential as a beneficial biomarker and therapeutic target. This review provides a detailed examination of the roles of CARMN, its evolutionary conservation, expression patterns, and regulatory mechanisms. It also outlines its significant implications in the diagnosis, prognosis, and treatment of these diseases, underscoring the need for further translational research to exploit its clinical potential.

MIR143HG promotes methylation of transcription factor HOXB7 promoter by recruiting methyltransferase DNMT1 to prevent the progression of colon cancer

In recent years, accumulating evidence has demonstrated the role of long noncoding RNAs (lncRNAs) in colon cancer. We aim to investigate the role of MIR143HG, also known as CARMN (Cardiac mesoderm enhancer-associated noncoding RNA) in colon cancer and explore the related mechanisms. An RNAseq data analysis was performed to screen differentially expressed lncRNAs associated with colon cancer. Next, MIR143HG expression was quantified in colon cancer cells. Moreover, the contributory roles of MIR143HG in the progression of colon cancer with the involvement of DNMT1 and HOXB7 (Homeobox B7) were evaluated after restored MIR143HG or depleted HOXB7. Finally, the effects of MIR143HG were investigated in vivo by measuring tumor formation in nude mice. High-throughput transcriptome sequencing was employed to validate the specific mechanisms by which MIR143HG and HOXB7 affect tumor growth in vivo. MIR143HG was found to be poorly expressed, while HOXB7 was highly expressed in colon cancer. MIR143HG could promote HOXB7 methylation by recruiting DNMT1 to reduce HOXB7 expression. Upregulation of MIR143HG or downregulation of HOXB7 inhibited cell proliferation, invasion and migration and facilitated apoptosis in colon cancer cells so as to delay the progression of colon cancer. The same trend was identified in vivo. Our study provides evidence that restoration of MIR143HG suppressed the progression of colon cancer via downregulation of HOXB7 through DNMT1-mediated HOXB7 promoter methylation. Thus, MIR143HG may be a potential candidate for the treatment of colon cancer.

RNA-binding protein RBM24 represses colorectal tumourigenesis by stabilising PTEN mRNA

BACKGROUND

RNA-binding motif protein 24 (RBM24) functions as a splicing regulator, which is critical for organ development and is dysregulated in human cancers. Here, we aim to uncover the biological function of RBM24 in colorectal tumourigenesis.

METHODS

Xenograft tumour model, Rbm24 knockout and Apcmin/+ mouse models were utilised. Colorectal cancer cells overexpressing or silencing RBM24 were established. RNA immunoprecipitation (RIP) assay was conducted to detect protein-RNA associations. Gene expression was measured by immunohistochemistry, western blotting, or quantitative PCR (qPCR).

RESULTS

Rbm24-knockout mice developed spontaneous colorectal adenomas with lower expression of phosphatase and tensin homolog (PTEN). Immunohistochemical staining for the proliferation markers Ki-67 and pHH3 and BrdU assay showed intestinal hyperplasia in Rbm24-knockout mice compared to wild-type mice. RBM24 expression in colorectal adenoma tissues of Apcmin/+ mouse was downregulated compared with adjacent normal samples and was positively correlated with PTEN expression. In vitro, RBM24 overexpression suppressed cell proliferation, migration, invasion and increased sensitivity to 5-FU or cisplatin in CRC cells. Mechanistically, RBM24 maintained PTEN mRNA stability by directly binding to the GT-rich region at positions 8101-8251 in the 3'-UTR of PTEN mRNA, prolonging the half-life of PTEN mRNA, thereby increasing PTEN expression. Hence, low expression of RBM24 downregulated PTEN mRNA, causing the activation of PI3K-Akt signalling in CRC cells. Furthermore, RBM24 expression in CRC tissues was lower than adjacent normal samples. RBM24 expression was positively correlated with PTEN expression and negatively correlated with Ki-67 level. CRC patients with high RBM24 expression had a favourable outcome.

CONCLUSIONS

Taken together, RBM24 expression is markedly lower in colorectal tumours than in para-carcinoma tissues. Rbm24-knockout mice develop spontaneous colorectal adenomas. RBM24 directly binds and stabilises PTEN mRNA, which could cause the suppression of CRC cell proliferation, migration and invasion, thereby repressing colorectal tumourigenesis. These findings support the tumour-suppressive role of RBM24. Targeting RBM24 holds strong promise for the diagnosis and treatment of CRC.

CARMN-NOTCH2 fusion transcript drives high NOTCH2 expression in glomus tumors of the upper digestive tract

Glomus tumors (GTs) are perivascular tumors mostly occurring in the distal extremities. Rare cases arise in the digestive tract and may be misdiagnosed with neuroendocrine or gastrointestinal stromal tumors. We aimed to specify the features of GT of the upper digestive tract. Clinical, histological, phenotypic, and molecular features of 16 digestive GTs were analyzed, of whom two underwent whole exome and RNA sequencing to search for gene alterations. RNA-sequencing disclosed a t(1:5)(p13;q32) translocation, which resulted in the fusion of CARMN and NOTCH2 in two GTs. The fusion gene encoded a protein sequence corresponding to the NOTCH2 intracellular domain that functions as transcription factor. These finding was supported by high expression of genes targeted by NOTCH. The CARMN-NOTCH2 translocation was detected in 14 out of 16 (88%) GTs of the upper digestive tract; but in only in two out of six cutaneous GTs (33%). Most digestive GT arose from the stomach (n = 13), and the others from duodenal (2) or oesophagous (1). Nuclear expression of NOTCH2 was detected in the 14 cases containing the fusion transcripts. The CARMN-NOTCH2 fusion transcript may contribute to activation of the NOTCH2 pathway in GT and drive tumor development. The high frequency of this translocation in GT of the upper digestive track suggest that detection of nuclear NOTCH2 expression may be useful diagnostic biomarker of these tumors.

Identification of the canonical and noncanonical role of miR-143/145 in estrogen-deficient bone loss

Rationale: Postmenopausal-induced bone loss is mainly caused by declining core transcription factors (TFs) of bone mesenchymal stem cells (BMSCs), but little is known about how miRNAs regulate chromatin structure remodeling of TFs gene to maintain BMSCs function in bone homeostasis. Methods: We examined the serum, salivary and bone samples from Pre- and Post-menopause women by paired analysis and confirmed canonical ceRNA role of MIR143HG and miR-143/145 complexes in cytoplasm and noncanonical role for SOX2 transcription in nucleus (FISH, qRT-PCR, immunostaining, Luciferase assays and ChIP). Moreover, we took advantage of transgenic mice under OVX-induced osteoporosis, studying the in vitro and in vivo effect of miR-143/145 deletion on BMSCs function and bone homeostasis. Last, using miRNA antagonism, antagomiR-143/145 were delivered into bone marrow to treat estrogen-deficient bone loss. Results: Here, we identified miR-143/145 as potential diagnostic candidates for postmenopausal osteoporosis, and miR-143/145 overexpression impaired BMSCs self-renewing and differentiation function. Mechanistically, we confirmed that cytoplasmic miR-143/145 and LncRNA MIR143HG, that controlled by ERβ, cooperatively regulated pluripotency genes translation via canonical ceRNA pathway, and MIR143HG cooperates with miR‑143 to nuclear translocation for co-activation of SOX2 transcription via opening promoter chromatin. Meanwhile, miR‑143/145 were shuttled into osteoclasts in extracellular vesicles and triggered osteoclastic activity by targeting Cd226 and Srgap2. Furthermore, miR-143/145-/- mice or using chemically‑modified antagomiR-143/145 significantly alleviated estrogen-deficient osteoporosis. Conclusions: Our findings reveal a canonical and noncanonical role of miR-143/145 in controlling BMSCs pluripotency and unfold their dual effect on bone formation and bone resorption, suggesting miR-143/145 as promising therapeutic targets for treating estrogen-deficient bone loss.

Circular RNA SMARCA5 suppressed non-small cell lung cancer progression by regulating miR-670-5p/RBM24 axis

Circular RNAs (circRNAs) have good stability and long half-life in blood and other body fluid, and possess regulatory effects on various biological processes as miRNA/RNA-binding protein sponges, or by competing endogenous RNA, indicating their great potential as biomarkers or targets of cancer therapy. In this study, we mainly explored the role and mechanism of circular RNA SMARCA5 (circsSMARCA5) in non-small cell lung cancer (NSCLC). Quantitative RT-PCR was applied to measure the expression levels of genes, and then, the relationships among circsSMARCA5, microRNA-670-5p (miR-670-5p), and RBM24 were further analyzed. Animal and cell experiments were performed to explore the functions of circsSMARCA5 in NSCLC cells. The results showed that circsSMARCA5 was expressed at low level in NSCLC tissues and cells, while miR-670-5p had high level in NSCLC tissues. Dual luciferase reporter assay verified that miR-670-5p was the target of circsSMARCA5, and RBM24 has the binding site of miR-670-5p. Further analysis showed that circsSMARCA5 could negatively regulate miR-670-5p and had positive relationship with RBM24. Moreover, circsSMARCA5 obviously inhibited tumor growth in vivo, reduced cell proliferation and increased cell apoptosis in vitro, while miR-670-5p mimic or RBM24 knockdown could reverse these effects. Thus, circsSMARCA5 may serve as an NSCLC suppressor by regulating the miR-670-5p/RBM24 axis, and it may have the potential to be a biomarker or therapeutic target for NSCLC.

miR-100 rs1834306 A>G Increases the Risk of Hirschsprung Disease in Southern Chinese Children

Background

Hirschsprung disease (HSCR) is a rare congenital gastrointestinal disease characterized by the absence of intestinal submucosal and myometrial ganglion cells. Recently, researches indicated that miR-100 regulated the growth, differentiation and apoptosis of neurons, and affected the functions of HSCR-associated pathways. While miR-100 rs1834306 A>G polymorphism was shown to modify the susceptibility to tumors, the association between this polymorphism and HSCR susceptibility is still unknown.

Methods

This was a case-control study consisting of 1470 HSCR cases and 1473 controls from southern China. DNA was genotyped by TaqMan real-time PCR. Odds ratios (ORs) and 95% confidence intervals (CIs) were used as statistical indicators.

Results

We found that miR-100 rs1834306 G allele and GG genotype significantly increased HSCR susceptibility (GG vs AA: adjusted OR=1.31, 95% CI=1.04-1.64, P=0.020; G vs A: adjusted OR=1.12, 95% CI=1.01-1.25, P=0.041; GG vs AA/AG: adjusted OR=1.30, 95% CI=1.07-1.59, P=0.010). In the stratified analysis, miR-100 rs1834306 GG genotype carriers had higher risk to develop HSCR in all clinical subtypes when compared with those with AA/AG genotypes, and OR was rising with HSCR aggravation (SHSCR: adjusted OR=1.28, 95% CI=1.03-1.59, P=0.029; LHSCR: adjusted OR=1.48, 95% CI=1.06-2.07, P=0.020; TCA: adjusted OR=2.12, 95% CI=1.22-3.69, P=0.008).

Conclusion

Our findings suggested that miR-100 rs1834306 A>G polymorphism was associated with increased HSCR susceptibility in southern Chinese children. Furthermore, miR-100 rs1834306 GG genotype had a greater genetic pathopoiesis in severe HSCR.

Correlation analysis between CARMEN variants and alcohol-induced osteonecrosis of the femoral head in the Chinese population

Background

Osteonecrosis of the femoral head (ONFH) is a complicated disease associated with trauma, hormone abuse and excessive alcohol consumption. Polymorphisms of long non-coding RNAs have been also linked with the development of ONFH. Our research aimed to explore the relationship between CARMEN (Cardiac Mesoderm Enhancer-Associated Non-Coding RNA) variants and ONFH risk.

Methods

Our study used Agena MassARRAY Assay to genotype 6 selected single nucleotide polymorphisms (SNPs) in 731 participants (308 alcohol-induced ONFH patients and 423 controls). We used odds ratios (ORs) and 95% confidence intervals (CIs) to calculate the effect of gene polymorphisms on the occurrence of alcohol-induced ONFH by logistic regression analysis and haplotype analysis.

Results

Our overall analysis illustrated that rs13177623 and rs12654195 had an association with a reduced risk of ONFH after adjustment for age and gender. We also found that rs13177623, rs12654195 and rs11168100 were associated with a decreased susceptibility to alcohol-induced ONFH in people ≤45 years. In addition, the necrotic sites stratification analysis showed that rs12654195 was only found to be related to alcohol-induced ONFH risk in the recessive model. In patients with different clinical stages, rs353300 was observed to be associated with a higher incidence of ONFH. Individuals with different genotypes of rs13177623, rs12654195 and rs11168100 had significantly different clinical parameters (cholinesterase, globulin, percentage of neutrophils and the absolute value of lymphocytes).

Conclusions

Our data provided new light on the association between CARMEN polymorphisms and alcohol-induced ONFH risk in the Chinese Han population.

RNA-Binding Protein Rbm24 as a Multifaceted Post-Transcriptional Regulator of Embryonic Lineage Differentiation and Cellular Homeostasis

RNA-binding proteins control the metabolism of RNAs at all stages of their lifetime. They are critically required for the post-transcriptional regulation of gene expression in a wide variety of physiological and pathological processes. Rbm24 is a highly conserved RNA-binding protein that displays strongly regionalized expression patterns and exhibits dynamic changes in subcellular localization during early development. There is increasing evidence that it acts as a multifunctional regulator to switch cell fate determination and to maintain tissue homeostasis. Dysfunction of Rbm24 disrupts cell differentiation in nearly every tissue where it is expressed, such as skeletal and cardiac muscles, and different head sensory organs, but the molecular events that are affected may vary in a tissue-specific, or even a stage-specific manner. Recent works using different animal models have uncovered multiple post-transcriptional regulatory mechanisms by which Rbm24 functions in key developmental processes. In particular, it represents a major splicing factor in muscle cell development, and plays an essential role in cytoplasmic polyadenylation during lens fiber cell terminal differentiation. Here we review the advances in understanding the implication of Rbm24 during development and disease, by focusing on its regulatory roles in physiological and pathological conditions.

MiR-143HG Gene Polymorphisms as Risk Factors for Gastric Cancer in Chinese Han Population

BACKGROUND

MicroRNA (miRNA) is a pivotal regulator of the occurrence and development of various cancers. And gastric cancer (GC) is one of the most common and deadly cancers in the world. The aim of this study is to explore whether the microRNA-143 host gene (miR-143HG) polymorphisms are correlated with the risk of GC.

METHODS

5 single-nucleotide polymorphisms (SNPs) were genotyped among 506 patients and 500 healthy controls in Han Chinese population. Multiple genetic models, stratification analysis and haplotype analysis were used to evaluate the association between miR-143HG polymorphisms and GC risk by calculating odds ratios (ORs), 95% confidence intervals (CIs).

RESULTS

Our results indicated that rs11168100 was associated with decreased risk of GC under the Codominant model (OR = 0.67, 95%CI = 0.52-0.88, p = 0.003), and under the Dominant model (OR = 0.72, 95%CI = 0.56-0.92, p = 0.009). Rs353300 was associated with increased risk of GC under the Recessive model (OR = 1.41, 95%CI = 1.06-1.87, p = 0.017). Further, rs11168100 and rs353300 were correlated with the susceptibility of GC (age > 60 years), and three SNPs (rs12654195, rs353303, and rs353300) were related with the risk of GC (age ≤ 60 years). In addition, two SNPs (rs12654195 and rs11168100) were found to be associated with decrease in the susceptibility of GC in the female subgroup. Rs353300 represented two-sided roles in the occurrence and development of GC in female. Finally, rs3533003 was associated with decreased risk of GC in stratified analysis of lymph node metastasis.

CONCLUSION

For the first time, our results provide some evidence on the polymorphisms of miR-143HG associated with GC risk in the Chinese Han population.

Integrative transcriptome data mining for identification of core lncRNAs in breast cancer

Background

Cumulative evidence suggests that long non-coding RNAs (lncRNAs) play an important role in tumorigenesis. This study aims to identify lncRNAs that can serve as new biomarkers for breast cancer diagnosis or screening.

Methods

First, the linear fitting method was used to identify differentially expressed genes from the breast cancer RNA expression profiles in The Cancer Genome Atlas (TCGA). Next, the diagnostic value of all differentially expressed lncRNAs was evaluated using a receiver operating characteristic (ROC) curve. Then, the top ten lncRNAs with the highest diagnostic value were selected as core genes for clinical characteristics and prognosis analysis. Furthermore, core lncRNA-mRNA co-expression networks based on weighted gene co-expression network analysis (WGCNA) were constructed, and functional enrichment analysis was performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID). The differential expression level and diagnostic value of core lncRNAs were further evaluated by using independent data set from Gene Expression Omnibus (GEO). Finally, the expression status and prognostic value of core lncRNAs in various tumors were analyzed based on Gene Expression Profiling Interactive Analysis (GEPIA).

Results

Seven core lncRNAs (LINC00478, PGM5-AS1, AL035610.1, MIR143HG, RP11-175K6.1, AC005550.4, and MIR497HG) have good single-factor diagnostic value for breast cancer. AC093850.2 has a prognostic value for breast cancer. AC005550.4 and MIR497HG can better distinguish breast cancer patients in early-stage from the advanced-stage. Low expression of MAGI2-AS3, LINC00478, AL035610.1, MIR143HG, and MIR145 may be associated with lymph node metastasis in breast cancer.

Conclusion

Our study provides candidate biomarkers for the diagnosis and prognosis of breast cancer, as well as a bioinformatics basis for the further elucidation of the molecular pathological mechanism of breast cancer.

Long non-coding RNA miR143HG predicts good prognosis and inhibits tumor multiplication and metastasis by suppressing mitogen-activated protein kinase and Wnt signaling pathways in hepatocellular carcinoma

AIM

The expression of microRNA143HG (miR143HG) was significantly downregulated in hepatocellular carcinoma (HCC) tissues by bioinformatics analysis. This study aimed to determine the role of miR143HG in HCC cell proliferation and metastasis.

METHODS

Fifty patients with HCC were divided into two groups based on median miR143HG expression levels. The correlation between miR143HG expression and prognosis, and the correlations between miR143HG expression and the patients' clinicopathological characteristics were evaluated based on the two groups. Gain-of-function and loss-of-function measurements of miR143HG were carried out to verify the biological function of miR143HG by Cell Counting Kit-8, EdU, Transwell, and western blotting assays and flow cytometric analysis. The underlying mechanism was explored by quantitative real-time polymerase chain reaction of miRNA (miR-155-5p and miR-26b-5p), luciferase reporter assay, western blotting of Wnt signaling pathway-related proteins (β-catenin, adenomatous polyposis coli (APC), glycogen synthase kinase 3β (GSK3β), ZEB1, and E-cadherin), mitogen-activated protein kinase (MAPK) signaling pathway-related proteins (extracellular signal-regulated kinase [ERK]1/2, p-ERK1/2, c-Jun N-terminal kinase (JNK), p-JNK, P38, and p-P38), and immunofluorescence staining of β-catenin.

RESULTS

miR143HG expression was markedly downregulated in HCC tissues and cells. Its expression was associated with the presence or absence of portal vein tumor thrombus, hepatitis B virus infection, relapse and metastasis, and Barcelona Clinic Liver Cancer stage. Additionally, miR143HG expression predicted a good prognosis and acted as an independent prognostic factor in HCC for overall survival. Overexpression of miR143HG suppressed HCC cell proliferation and metastasis, and induced cell cycle arrest and apoptosis. Consistently, the depletion of miR143HG resulted in the opposite phenomenon of the aforementioned results. miR143HG inhibits miR-155 expression; miR-155 directly targets APC, which is a negative regulator of the Wnt/β-catenin pathway, so miR143HG can act on the Wnt pathway. miR143HG was further found to reduce the expression of β-catenin and block the nuclear accumulation of β-catenin, ultimately inhibiting the activation of the Wnt pathway. It inhibits the expression of Wnt downstream target gene ZEB1, and then E-cadherin expression is increased and cell motility is inhibited. Furthermore, miR143HG exerts its antiproliferative function by influencing the MAPK signaling pathway and then inducing G₂ /M arrest in cells.

CONCLUSION

This study showed that miR143HG plays critical roles in the development and progression of HCC by suppressing the MAPK and Wnt signaling pathways.

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.

LncRNA miR143HG suppresses bladder cancer development through inactivating Wnt/β-catenin pathway by modulating miR-1275/AXIN2 axis

Although increasing long noncoding RNAs (lncRNAs) have been identified by high-throughput sequencing, their functions in human cancer remain largely unknown. The function of lncRNA miR143HG has not been explored before. In the present study, we found that miR143HG expression was significantly downregulated in bladder cancer tissues (BCa) compared with normal tissues. We showed that miR143HG high expression was associated with a high survival rate in BCa patients. Gain-of-function assays demonstrated that miR143HG overexpression suppressed the proliferation, arrested cell cycle progression, and attenuated migration and invasion of BCa cells in vitro. In vivo assay illustrated that ectopic expression of miR143HG inhibited BCa growth in vivo. Mechanistically, miR143HG was identified to inhibit the level of miR-1275, whereas miR-1275 directly targeted AXIN2, a negative regulator of the Wnt/β-catenin pathway. Restoration of miR-1275 or knockdown of AXIN2 significantly rescued the proliferation, migration, and invasion abilities of BCa cells. In summary, our findings demonstrated that miR143HG/miR-1275/AXIN2 axis regulates BCa development by modulating the Wnt/β-catenin pathway.

Targeting MicroRNA-143 Leads to Inhibition of Glioblastoma Tumor Progression

Glioblastoma (GBM) is the most common and aggressive of all brain tumors, with a median survival of only 14 months after initial diagnosis. Novel therapeutic approaches are an unmet need for GBM treatment. MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression at the post-transcriptional level. Several dysregulated miRNAs have been identified in all cancer types including GBM. In this study, we aimed to uncover the role of miR-143 in GBM cell lines, patient samples, and mouse models. Quantitative real-time RT-PCR of RNA extracted from formalin-fixed paraffin-embedded (FFPE) samples showed that the relative expression of miR-143 was higher in GBM patients compared to control individuals. Transient transfection of GBM cells with a miR-143 oligonucleotide inhibitor (miR-143-inh) resulted in reduced cell proliferation, increased apoptosis, and cell cycle arrest. SLC30A8, a glucose metabolism-related protein, was identified as a direct target of miR-143 in GBM cells. Moreover, multiple injections of GBM tumor-bearing mice with a miR-143-inh-liposomal formulation significantly reduced tumor growth compared to control mice. The reduced in vitro cell growth and in vivo tumor growth following miRNA-143 inhibition suggests that miR-143 is a potential therapeutic target for GBM therapy.

Alternative Splicing in Genetic Diseases: Improved Diagnosis and Novel Treatment Options

Alternative splicing is an important mechanism to regulate gene expression and to expand the repertoire of gene products in order to accommodate an increase in complexity of multicellular organisms. It needs to be precisely regulated, which is achieved via RNA structure, splicing factors, transcriptional regulation, and chromatin. Changes in any of these factors can lead to disease. These may include the core spliceosome, splicing enhancer/repressor sequences and their interacting proteins, the speed of transcription by RNA polymerase II, and histone modifications. While the basic principle of splicing is well understood, it is still very difficult to predict splicing outcome, due to the multiple levels of regulation. Current molecular diagnostics mainly uses Sanger sequencing of exons, or next-generation sequencing of gene panels or the whole exome. Functional analysis of potential splicing variants is scarce, and intronic variants are often not considered. This likely results in underestimation of the percentage of splicing variants. Understanding how sequence variants may affect splicing is not only crucial for confirmation of diagnosis and for genetic counseling, but also for the development of novel treatment options. These include small molecules, transsplicing, antisense oligonucleotides, and gene therapy. Here we review the current state of molecular mechanisms of splicing regulation and how deregulation can lead to human disease, diagnostics to detect splicing variants, and novel treatment options based on splicing correction.