ECRG4 Represses Cell Proliferation and Invasiveness via NFIC/OGN/NF-κB Signaling Pathway in Bladder Cancer

Dihydroartemisinin suppresses the tumorigenesis of esophageal carcinoma by elevating DAB2IP expression in a NFIC-dependent manner

Dihydroartemisinin (DHA) has been identified to have the anticancer and anti-inflammatory activities. Disabled homolog 2 interacting protein (DAB2IP) is a well-recognized tumor suppressor. Both DHA and DAB2IP were proven to have suppressing effects on esophageal carcinoma (ESCA) tumorigenesis. However, whether DHA regulated ESCA cells via DAB2IP and its mechanism are still vague. Functional analyses were conducted using MTT, tube formation, sphere formation, and transwell assays in vitro as well as Tumor formation experiments in mice. Levels of genes and proteins were assayed by qRT-PCR and western blotting analyses. The interaction between DAB2IP and Nuclear Factor I C (NFIC) was confirmed using bioinformatics analysis and dual-luciferase reporter assay. DHA treatment suppressed ESCA cell angiogenesis, stemmess, migration, and invasion. DAB2IP level was decreased in ESCA tissues and cells, and DHA elevated DAB2IP expression in ESCA cells. Functionally, DAB2IP overexpression impaired ESCA cell angiogenesis, stemmess, migration and invasion. Mechanistically, NFIC had binding sites on the promoter region and directly targeted DAB2IP. DHA could up-regulate DAB2IP expression via NFIC. Moreover, NFIC was also decreased in ESCA tissues and cells, and its overexpression had anticancer activity in ESCA cells. In addition, DAB2IP knockdown reversed the anticancer effects of NFIC or DHA on ESCA cells. In further in vivo analysis, DHA also suppressed ESCA growth by regulating DAB2IP expression. DHA suppressed the tumorigenesis of ESCA by elevating DAB2IP expression in an NFIC-dependent manner, suggesting the potential clinical application of DHA in ESCA treatment.

NFIC mediates m6A mRNA methylation to orchestrate transcriptional and post-transcriptional regulation to represses malignant phenotype of non-small cell lung cancer cells

BACKGROUND

Multiple genetic and epigenetic regulatory mechanisms are crucial in the development and tumorigenesis process. Transcriptional regulation often involves intricate relationships and networks with post-transcriptional regulatory molecules, impacting the spatial and temporal expression of genes. However, the synergistic relationship between transcription factors and N6-methyladenosine (m6A) modification in regulating gene expression, as well as their influence on the mechanisms underlying the occurrence and progression of non-small cell lung cancer (NSCLC), requires further investigation. The present study aimed to investigate the synergistic relationship between transcription factors and m6A modification on NSCLC.

METHODS

The transcription factor NFIC and its potential genes was screened by analyzing publicly available datasets (ATAC-seq, DNase-seq, and RNA-seq). The association of NFIC and its potential target genes were validated through ChIP-qPCR and dual-luciferase reporter assays. Additionally, the roles of NFIC and its potential genes in NSCLC were detected in vitro and in vivo through silencing and overexpression assays.

RESULTS

Based on multi-omics data, the transcription factor NFIC was identified as a potential tumor suppressor of NSCLC. NFIC was significantly downregulated in both NSCLC tissues and cells, and when NFIC was overexpressed, the malignant phenotype and total m6A content of NSCLC cells was suppressed, while the PI3K/AKT pathway was inactivated. Additionally, we discovered that NFIC inhibits the expression of METTL3 by directly binding to its promoter region, and METTL3 regulates the expression of KAT2A, a histone acetyltransferase, by methylating the m6A site in the 3'UTR of KAT2A mRNA in NSCLC cells. Intriguingly, NFIC was also found to negatively regulate the expression of KAT2A by directly binding to its promoter region.

CONCLUSIONS

Our findings demonstrated that NFIC suppresses the malignant phenotype of NSCLC cells by regulating gene expression at both the transcriptional and post-transcriptional levels. A deeper comprehension of the genetic and epigenetic regulatory mechanisms in tumorigenesis would be beneficial for the development of personalized treatment strategies.

A potential role of human esophageal cancer-related gene-4 in cardiovascular homeostasis

Human esophageal cancer related gene-4 (ECRG-4) encodes a 148-aminoacid pre-pro-peptide that can be processed tissue-dependently into multiple small peptides possessing multiple functions distinct from, similar to, or opposite to the tumor suppressor function of the full-length Ecrg4. Ecrg-4 is covalently bound to the cell surface through its signal peptide, colocalized with the innate immunity complex (TLR4-CD14-MD2), and functions as a 'sentinel' molecule in the maintenance of epithelium and leukocyte homeostasis, meaning that the presence of Ecrg-4 on the cell surface signals the maintained homeostasis, whereas the loss of Ecrg-4 due to tissue injury activates pro-inflammatory and tissue proliferative responses, and the level of Ecrg-4 gradually returns to its pre-injury level upon wound healing. Interestingly, Ecrg-4 is also highly expressed in the heart and its conduction system, endothelial cells, and vascular smooth muscle cells. Accumulating evidence has shown that Ecrg-4 is involved in cardiac rate/rhythm control, the development of atrial fibrillation, doxorubicin-induced cardiotoxicity, the ischemic response of the heart and hypoxic response in the carotid body, the pathogenesis of atherosclerosis, and likely the endemic incidence of idiopathic dilated cardiomyopathy. These preliminary discoveries suggest that Ecrg-4 may function as a 'sentinel' molecule in cardiovascular system as well. Here, we briefly review the basic characteristics of ECRG-4 as a tumor suppressor gene and its regulatory functions on inflammation and apoptosis; summarize the discoveries about its distribution in cardiovascular system and involvement in the development of CVDs, and discuss its potential as a novel therapeutic target for the maintenance of cardiovascular system homeostasis.

Analysis of the characteristics of immune infiltration in endometrial carcinoma and its relationship with prognosis based on bioinformatics

To explore immune-related molecules that affect the prognosis of endometrial carcinoma (EC) using bioinformatic data mining. The expression data related to EC were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. After differential expression analysis, the intersection with immune related genes in the ImmPort database was used to obtain immune related differentially expressed genes (IRDEGs). The correlation between clinicopathological information and the prognosis of IRDEGs was further analyzed to obtain prognosis related differentially expressed immune genes (PRDEIG). Gene correlation analysis and Gene Set Enrichment Analysis (GSEA) enrichment analysis showed that PRDEIG was enriched in cancer-related functional pathways. We then analyzed the relationship between PRDEIG and immune cell infiltration, and further analyzed the mRNA and protein expression of PRDEIG in EC using TCGA and the human protein expression atlas (THPA) databases. After the intersection of the differential expression analysis results and immune-related genes, 4 IRDEGs were obtained: osteoglycin (OGN), LTBP4, CXCL12, and SPP1. After analyzing the relationship between 4 IRDEGs and clinicopathological parameters and prognosis of patients with EC, revealed that only OGN was not only related to tumor immunity, but also affected the prognosis of patients with EC. Gene correlation and GSEA enrichment of OGN were analyzed. The results showed that OGN was significantly enriched in 6 functional pathways: epithelial mesenchymal transition, KRAS signaling up, myogenesis, UV response, allograft rejection and apical junction. In addition, it was also found that OGN was significantly correlated with a variety of immune cells. The results of TCGA and THPA database showed that the mRNA and protein expression levels of OGN decreased in EC. OGN may affect the epithelial mesenchymal transformation (EMT) of tumor by affecting the infiltration of tumor immune cells.

Complex and pleiotropic signaling pathways regulated by the secreted protein augurin

The secreted protein augurin, the product of the tumor suppressor gene Ecrg4, has been identified as a peptide hormone in the human proteome in 2007. Since then, a number of studies have been carried out to highlight its structure and processing and its potential roles in physiopathology. Although augurin has been shown to be implicated in a variety of processes, ranging from tumorigenesis, inflammation and infection to neural stem cell proliferation, hypothalamo-pituitary adrenal axis regulation and osteoblast differentiation, the molecular mechanisms of its biological effects and the signaling pathways it regulates are still poorly characterized. Here we provide a comprehensive overview of augurin-dependent signal transduction pathways. Because of their secreted nature and the potential to be manipulated pharmacologically, augurin and its derived peptides represent attractive targets for diagnostic development and discovery of new therapeutic agents for the human diseases resulting from the deregulation of the signaling cascades they modulate. From this perspective, the characterization of the precise nature of augurin derived peptides and the identification of the receptor(s) on the cell surface conveying augurin signaling to downstream effectors are crucial to develop agonists and antagonists for this protein. Video abstract.

Pan-cancer analyses reveal molecular and clinical characteristics of cuproptosis regulators

Imbalance in copper homeostasis can be lethal. A recent study found that excess copper induces cell death in a way that has never been characterized before, which is dependent on mitochondrial stress and is referred to as "cuproptosis." The role of cuproptosis in tumors has not yet been elucidated. In this study, we revealed the complex and important roles of cuproptosis regulators and cuproptosis activity in tumors via a comprehensive analysis of multiomics data from more than 10,000 samples of 33 tumor types. We found that the cyclin-dependent kinase inhibitor 2A is the most frequently altered cuproptosis regulator, and the cuproptosis regulator expression is dysregulated in various tumors. Additionally, we developed a cuproptosis activity score to reflect the overall cuproptosis level. On the basis of the expression levels of cuproptosis regulators, tumors can be divided into two clusters with different cuproptosis activities and survival outcomes. Importantly, cuproptosis activity was found to be associated with the prognosis of multiple tumors and multiple tumor-related pathways, including fatty acid metabolism and remodeling of the tumor microenvironment. Furthermore, cuproptosis increased the sensitivity to multiple drugs and exhibited potential to predict the outcome of immunotherapy. We also comprehensively identified cuproptosis-related microRNAs, long noncoding RNAs, and transcription factors. We provided the code corresponding to the results of this study in GitHub (https://github.com/Changwuuu/Cuproptosis-pancancer.git) for reference. In summary, this study reveals important molecular and clinical characteristics of cuproptosis regulators and cuproptosis activity in tumors, and suggests the use of cuproptosis as a promising tumor therapeutic approach. This study provides an important reference point for future cuproptosis-related research.

Nuclear factor I-C overexpression promotes monocytic development and cell survival in acute myeloid leukemia

Nuclear factor I-C (NFIC) belongs to a family of NFI transcription factors that binds to DNA through CAATT-boxes and are involved in cellular differentiation and stem cell maintenance. Here we show NFIC protein is significantly overexpressed in 69% of acute myeloid leukemia patients. Examination of the functional consequences of NFIC overexpression in HSPCs showed that this protein promoted monocytic differentiation. Single-cell RNA sequencing analysis further demonstrated that NFIC overexpressing monocytes had increased expression of growth and survival genes. In contrast, depletion of NFIC through shRNA decreased cell growth, increased cell cycle arrest and apoptosis in AML cell lines and AML patient blasts. Further, in AML cell lines (THP-1), bulk RNA sequencing of NFIC knockdown led to downregulation of genes involved in cell survival and oncogenic signaling pathways including mixed lineage leukemia-1 (MLL-1). Lastly, we show that NFIC knockdown in an ex vivo mouse MLL::AF9 pre-leukemic stem cell model, decreased their growth and colony formation and increased expression of myeloid differentiation markers Gr1 and Mac1. Collectively, our results suggest that NFIC is an important transcription factor in myeloid differentiation as well as AML cell survival and is a potential therapeutic target in AML.

A potential link between aberrant expression of ECRG4 and atrial fibrillation

Esophageal cancer-related gene-4 (ECRG4), a 148-amino acid propertied and new tumor suppressor, is initially cloned from the normal esophageal epithelium. ECRG4 was found to be expressed not only in esophageal tissues but also in cardiomyocytes. Previous studies demonstrated that ECRG4 is constitutively expressed in esophageal epithelial cells, and its degree of downregulation is directly proportional to prognosis in patients with esophageal cancer. In the heart, ECRG4 shows greater expression in the atria than in the ventricles, which accounts for its heterogeneity. Downregulation of ECRG4 expression level correlates with esophageal cancer, as well as myocardial injuries and arrhythmias. As a result, this review summarizes the possible susceptibility gene, ECRG4 and its associated molecular mechanisms in cancer patients with atrial fibrillation and myocardial injury. The review begins by describing ECRG4's biological background, discusses its expression in the cardiovascular system, lists the clinical and animal research related to the downregulation of ECRG4 in atrial fibrillation, and focuses on its potential role in atrial fibrillation. Downregulation of ECRG4 may increase the risk of atrial fibrillation by affecting ion channels, MMPs expression and inflammatory response. We will then discuss how ECRG4 can be used in the treatment of tumors and arrhythmias, and provide a novel possible strategy to reduce the occurrence of perioperative cardiovascular adverse events in patients with tumors such as esophageal cancer and gastric cancer.

Loss of Ecrg4 improves calcium oxalate nephropathy

Kidney stone is one of the most frequent urinary tract diseases, affecting 10% of the population and displaying a high recurrence rate. Kidney stones are the result of salt supersaturation, including calcium and oxalate. We have previously identified Esophageal cancer-related gene 4 (Ecrg4) as being modulated by hypercalciuria. Ecrg4 was initially described as a tumor suppressor gene in the esophagus. Lately, it was shown to be involved as well in apoptosis, cell senescence, cell migration, inflammation and cell responsiveness to chemotherapy. To the best of our knowledge, nothing is known about ECRG4's function in the renal tissue and its relationship with calciuria. We hypothesized that the increased expression of Ecrg4 mRNA is triggered by hypercalciuria and might modulate intratubular calcium-oxalate precipitation. In this study, we have first (i) validated the increased Ecrg4 mRNA in several types of hypercalciuric mouse models, then (ii) described the Ecrg4 mRNA expression along the nephron and (iii) assessed ECRG4's putative role in calcium oxalate nephropathy. For this, Ecrg4 KO mice were challenged with a kidney stone-inducing diet, rich in calcium and oxalate precursor. Taken together, our study demonstrates that Ecrg4's expression is restricted mainly to the distal part of the nephron and that the Ecrg4 KO mice develop less signs of tubular obstruction and less calcium-oxalate deposits. This promotes Ecrg4 as a modulator of renal crystallization and may open the way to new therapeutic possibilities against calcium oxalate nephropathy.

A novel immune-related RNA-binding proteins signature to predict survival and therapeutic responses in prostate cancer

BACKGROUND

The present study aims to identify immune-related RBPs signature to predict prognosis and therapy response in prostate cancer.

METHODS

Differentially expressed RBPs were compared and visualized using R packages. Immune-related RBPs were selected by Pearson correlation analysis. The prognostic immune-related RBPs were identified using the Kaplan-Meier method and LASSO regression. A multivariable Cox regression model was used to construct immune-related RBPs signature.

RESULTS

We constructed a prognostic predictive risk model of prostate cancer containing ten immune-related RBP genes. We found that high-risk prostate cancer patients presented poorer prognosis, higher tumor immune cell infiltration, higher rates of genomic alterations, and were more sensitive to targeted and immunotherapy than the low-risk group.

CONCLUSIONS

The immune-related RBPs' signature is an independent prognostic marker that could help screen patients with advanced prostate cancer who are better suited for targeted and immunotherapy.

ECRG4 acts as a tumor suppressor in nasopharyngeal carcinoma by suppressing the AKT/GSK3β/β-catenin signaling pathway

Nasopharyngeal carcinoma (NPC) is a malignant tumor with a poor prognosis. Studies have shown that esophageal carcinoma related gene 4 (ECRG4) is hypermethylated and significantly downregulated in NPC tissues. However, the role of ECRG4 in NPC, and in particular the underlying molecular mechanism, is largely unclear. In this study, using immunohistochemical staining of ECRG4 in NPC and normal specimens, we confirmed that ECRG4 was downregulated in human NPC tissues. In addition, various biological and molecular studies were carried out and the results showed that ECRG4 exerted anticancer effect in NPC, including inhibiting cell growth, migration, and invasion of NPC cells in vitro. Moreover, restoring ECRG4 expression suppressed the in vivo tumorigenesis of CNE2 cells. ECRG4 inhibited AKT/GSK3β/β-catenin signaling, as well as the downstream targets of β-catenin. LiCl treatment, which reduced GSK3β phosphorylation and upregulated β-catenin expression, restored the invasive ability of ECRG4-overexpressing NPC cells. Furthermore, we showed that the DNA methylation inhibitor 5-aza-dC reduced ECRG4 methylation and the invasive ability of negative control cells, but not that of ECRG4-overexpressing cells, suggesting that the inhibitory effect of 5-aza-dC depends on low expression of ECRG4. Collectively, our results demonstrated that ECRG4 downregulation contributed to NPC growth and invasion by activating AKT/GSK3β/β-catenin signaling pathway. ECRG4 could be a promising therapeutic target for the treatment of NPC.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10616-022-00520-8.

Is Autophagy Always a Barrier to Cisplatin Therapy?

Cisplatin has long been a first-line chemotherapeutic agent in the treatment of cancer, largely for solid tumors. During the course of the past two decades, autophagy has been identified in response to cancer treatments and almost uniformly detected in studies involving cisplatin. There has been increasing recognition of autophagy as a critical factor affecting tumor cell death and tumor chemoresistance. In this review and commentary, we introduce four mechanisms of resistance to cisplatin followed by a discussion of the factors that affect the role of autophagy in cisplatin-sensitive and resistant cells and explore the two-sided outcomes that occur when autophagy inhibitors are combined with cisplatin. Our goal is to analyze the potential for the combinatorial use of cisplatin and autophagy inhibitors in the clinic.

Insulin-like growth factor 2 mRNA-binding protein 2-regulated alternative splicing of nuclear factor 1 C-type causes excessive granulosa cell proliferation in polycystic ovary syndrome

Objectives

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder. Insulin‐like growth factor 2 mRNA‐binding protein 2 (IGF2BP2) serves as an HMGA2 target gene to promote the proliferation of granulosa cells (GCs). However, it is still unclear whether IGF2BP2 participates in the pathogenesis of PCOS as RNA binding protein (RBP). In this study, we aimed to elucidate IGF2BP2‐interacting transcripts, global transcriptome together with alternative splicing in GCs to eventually uncover potential mechanisms of PCOS pathogenesis.

Materials and Methods

The expression of IGF2BP2 in GCs from PCOS patients was detected using quantitative reverse transcription PCR (RT‐qPCR) and western blot. We captured IGF2BP2‐interacting transcripts, global transcriptome together with alternative splicing by RNA immunoprecipitation sequencing (RIP‐seq) and RNA sequencing (RNA‐seq). KGN cells transfected with IGF2BP2 overexpressing plasmids and nuclear factor 1 C‐type (NFIC) siRNAs, were applied to CCK‐8, EdU and TUNEL assays.

Results

IGF2BP2 was highly expressed in GCs from PCOS patients. As an RBP, it preferentially bound to the 3′and 5′UTRs of mRNAs with GGAC motif and a newly found GAAG motif. The overexpression of IGF2BP2 changed the transcriptome profile of KGN cells. IGF2BP2 functioned to regulate alternative splicing events and promote cell proliferation through inhibiting exon skipping events of NFIC.

Conclusion

In conclusion, we demonstrated that IGF2BP2 promotes GC proliferation via regulating alternative splicing of NFIC in PCOS. The findings help to better understand the roles of IGF2BP2 in the pathogenesis of PCOS.

Machine Learning analysis of high-grade serous ovarian cancer proteomic dataset reveals novel candidate biomarkers

Ovarian cancer is one of the most common gynecological malignancies, ranking third after cervical and uterine cancer. High-grade serous ovarian cancer (HGSOC) is one of the most aggressive subtype, and the late onset of its symptoms leads in most cases to an unfavourable prognosis. Current predictive algorithms used to estimate the risk of having Ovarian Cancer fail to provide sufficient sensitivity and specificity to be used widely in clinical practice. The use of additional biomarkers or parameters such as age or menopausal status to overcome these issues showed only weak improvements. It is necessary to identify novel molecular signatures and the development of new predictive algorithms able to support the diagnosis of HGSOC, and at the same time, deepen the understanding of this elusive disease, with the final goal of improving patient survival. Here, we apply a Machine Learning-based pipeline to an open-source HGSOC Proteomic dataset to develop a decision support system (DSS) that displayed high discerning ability on a dataset of HGSOC biopsies. The proposed DSS consists of a double-step feature selection and a decision tree, with the resulting output consisting of a combination of three highly discriminating proteins: TOP1, PDIA4, and OGN, that could be of interest for further clinical and experimental validation. Furthermore, we took advantage of the ranked list of proteins generated during the feature selection steps to perform a pathway analysis to provide a snapshot of the main deregulated pathways of HGSOC. The datasets used for this study are available in the Clinical Proteomic Tumor Analysis Consortium (CPTAC) data portal (https://cptac-data-portal.georgetown.edu/).

Cardiac Expression of Esophageal Cancer-Related Gene-4 is Regulated by Sp1 and is a Potential Early Target of Doxorubicin-Induced Cardiotoxicity

Esophageal Cancer-Related Gene 4 (Ecrg4) expressed in cardiomyocytes and the cardiac conduction system is downregulated during cardiac ischemia and atrial fibrillation. To explore whether Ecrg4 plays any role in doxorubicin (DOX)-induced cardiotoxicity. Rats and neonatal rat cardiomyocytes (NRCMs) were employed to study the effect of DOX on Ecrg4 transcription. Bioinformatics combined with promoter analysis were used to map the rat Ecrg4 promoter. ChIP assay was used to evaluate the binding of Sp1 to the Ecrg4 promoter. Transient transfection was used to study the effect of Sp1 on the expression of endogenous Ecrg4. DOX decreased endogenous Ecrg4 gene expression in the heart and cultured NRCMs. In silico analysis showed that the 5'UTR immediately upstream of the start codon ATG, harbors a putative promoter that is GC-rich, and contains CpG islands, multiple overlapping Sp1sites. Transcription is initiated mainly on the 'C' at - 15. Serial 5'-deletion combined with dual-luciferase assays showed that the rat Ecrg4 core promoter resides at - 1/- 800. Sp1 transactivated Ecrg4 gene, which was almost abolished by DOX. Furthermore, ChIP assay showed that Sp1 specifically bound to the Ecrg4 promoter was interrupted by DOX. Finally, DOX suppressed Sp1 protein expression, and restoration of Sp1 increased Ecrg4 expression that was resistant to DOX-induced Ecrg4 downregulation. Importantly, cardiomyocyte-specific loss of Ecrg4 significantly enriched the differentially expressed proteins in the signaling pathways commonly involved in DOX-induced cardiotoxicity. Our results indicate that Sp1 mediates DOX-induced suppression of Ecrg4, which may contribute indirectly to its cardiotoxicity.

Association of miR-9-5p and NFIC in the progression of gastric cancer

BACKGROUND

Gastric cancer is the most common malignant neoplasm of digestive system. Herein, we aim to detect the expression of nuclear factor I C (NFIC) in gastric cancer cells, and to explore the effect and mechanism of its expression on the development of gastric cancer.

METHODS

qPCR and Western blot assays were carried out to detect NFIC expression. Then, BGC-823 and SGC-7901 cell lines were selected to perform the following functional experiments. The function of NFIC on gastric cancer cells was analyzed by biological experiments. The associations between miR-9-5p and NFIC were searched on the bioinformatics website and identified by dual luciferase assay. The effects of miR-9-5p and NFIC on cells were verified by co-transfection experiments. The related genes expression was examined by Western blot.

RESULTS

A marked augmentation of NFIC was observed in gastric cancer cells. Knockdown of NFIC significantly inhibited the viability, colony formation, invasion, and migration of gastric cancer cells. Overexpression of miR-9-5p obviously suppressed the viability, colony formation, invasion, and migration of gastric cancer cells, and this phenomenon was aggravated by si-NFIC. Additionally, the expression levels of PCNA, vimentin, and Snail were obviously decreased after miR-9-5p mimic or/and si-NFIC treatment.

CONCLUSIONS

These results suggested that NFIC was highly expressed in gastric cancer cells, and knockdown of NFIC suppressed the growth and mobility of gastric cancer cells; miR-9-5p was identified as an upstream regulator of NFIC and suppressed the malignant behaviors of gastric cancer cells by targeting NFIC through affecting PCNA, vimentin, and Snail expression.

Nuclear factor I-C disrupts cellular homeostasis between autophagy and apoptosis via miR-200b-Ambra1 in neural tube defects

Impaired autophagy and excessive apoptosis disrupt cellular homeostasis and contribute to neural tube defects (NTDs), which are a group of fatal and disabling birth defects caused by the failure of neural tube closure during early embryonic development. However, the regulatory mechanisms underlying NTDs and outcomes remain elusive. Here, we report the role of the transcription factor nuclear factor I-C (NFIC) in maintaining cellular homeostasis in NTDs. We demonstrated that abnormally elevated levels of NFIC in a mouse model of NTDs can interact with the miR-200b promoter, leading to the activation of the transcription of miR-200b, which plays a critical role in NTD formation, as reported in our previous study. Furthermore, miR-200b represses autophagy and triggers apoptosis by directly targeting the autophagy-related gene Ambra1 (Autophagy/Beclin1 regulator 1). Notably, miR-200b inhibitors mitigate the unexpected effects of NFIC on autophagy and apoptosis. Collectively, these results indicate that the NFIC-miR-200b-Ambra1 axis, which integrates transcription- and epigenome-regulated miRNAs and an autophagy regulator, disrupts cellular homeostasis during the closure of the neural tube, and may provide new insight into NTD pathogenesis.

Mechanism of methyltransferase like 3 in epithelial-mesenchymal transition process, invasion, and metastasis in esophageal cancer

Methyltransferase like 3 (METTL3) has been identified to serve as a definitive inducer in cancer progression. This study sought to analyze the regulatory mechanism of METTL3 in epithelial-mesenchymal transition (EMT), invasion, and metastasis in esophageal cancer (ESCA). The METTL3 expressions in cancer tissues and cells were detected with extensive analysis of its correlation with clinical baseline data. The cells were transfected with sh-RNA-METTL3 and microRNA (miR)-20a-5p mimic, followed by evaluation of invasion, migration, and EMT. The N6-methyladenosine (m6A) level and enrichment of DiGeorge Critical Region 8 (DGCR8) and m6A were observed. The binding relationship between miR-20a-5p and Nuclear Factor I-C (NFIC) was verified, followed by Pearson correlation analysis. A subcutaneous tumor formation assay was conducted prior to observation of lung metastases. Our results revealed that METTL3 was highly expressed in ESCA patients and associated with severe lymph node involvement and distant metastasis. METTL3 downregulation radically inhibited the invasiveness, migration, and EMT. METTL3 elevated the miR-20a-5p expression via improving m6A modification. METTL3 inhibition downregulated the miR-20a-5p expression. Moreover, miR-20a-5p upregulation facilitated ESCA cell invasiveness and migration by targeting NFIC transcription. METTL3 inhibition suppressed tumor growth and lung metastasis in vivo. Overall, METTL3 promoted m6A modification and the binding of DGCR8 to miR-20a-5p to further elevate the miR-20a-5p expression and inhibit NFIC transcription, thus promoting EMT, invasion and migration.

C2orf40 inhibits hepatocellular carcinoma through interaction with UBR5

BACKGROUND AND AIM

Hepatocellular carcinoma (HCC) urgently needs a marker for early diagnosis and targeted treatment. C2orf40 has been identified as a tumor suppressor gene in many cancers. However, the precise role and regulatory mechanism by C2orf40 contribute to HCC remain elusive and merit exploration.

METHODS

Reverse-transcription PCR, quantitative real-time PCR, and methylation-specific PCR were used to detect expression and methylation of C2orf40 in HCC cell lines or tissues. The effects of C2orf40 in liver cancer cells were examined via colony formation, CCK8, transwell, and flow cytometric assays. The effect of C2orf40 on tumorigenesis in vivo was determined by xenografts and immunohistochemical analysis. Western blot, indirect immunofluorescence, Co-IP, and cycloheximide (CHX) were used to further investigate the potential mechanism of C2orf40.

RESULTS

The down-regulation of C2orf40 in hepatocellular cancer tissue samples is often related to the degree of methylation of its promoter CpG. The recovery of C2orf40 expression in HCC cell lines can induce G0/G1 phase arrest and apoptosis and also inhibit cell migration and invasion by reversing the epithelial-mesenchymal transition (EMT) process, both in vivo and in vitro. In addition, C2orf40 can increase the expression of p21 through interaction with UBR5.

CONCLUSIONS

Low expression levels of C2orf40 are related to the hypermethylation of its promoter. C2orf40 can inhibit HCC through UBR5-dependent or p53-independent mechanisms. C2orf40 may be a diagnostic biomarker and a potential therapeutic target in HCC.

MCPIP1-mediated NFIC alternative splicing inhibits proliferation of triple-negative breast cancer via cyclin D1-Rb-E2F1 axis

Triple-negative breast cancer (TNBC) is the most aggressive subtype with the worst prognosis and the highest metastatic and recurrence potential, which represents 15–20% of all breast cancers in Chinese females, and the 5-year overall survival rate is about 80% in Chinese women. Recently, emerging evidence suggested that aberrant alternative splicing (AS) plays a crucial role in tumorigenesis and progression. AS is generally controlled by AS-associated RNA binding proteins (RBPs). Monocyte chemotactic protein induced protein 1 (MCPIP1), a zinc finger RBP, functions as a tumor suppressor in many cancers. Here, we showed that MCPIP1 was downregulated in 80 TNBC tissues and five TNBC cell lines compared to adjacent paracancerous tissues and one human immortalized breast epithelial cell line, while its high expression levels were associated with increased overall survival in TNBC patients. We demonstrated that MCPIP1 overexpression dramatically suppressed cell cycle progression and proliferation of TNBC cells in vitro and repressed tumor growth in vivo. Mechanistically, MCPIP1 was first demonstrated to act as a splicing factor to regulate AS in TNBC cells. Furthermore, we demonstrated that MCPIP1 modulated NFIC AS to promote CTF5 synthesis, which acted as a negative regulator in TNBC cells. Subsequently, we showed that CTF5 participated in MCPIP1-mediated antiproliferative effect by transcriptionally repressing cyclin D1 expression, as well as downregulating its downstream signaling targets p-Rb and E2F1. Conclusively, our findings provided novel insights into the anti-oncogenic mechanism of MCPIP1, suggesting that MCPIP1 could serve as an alternative treatment target in TNBC.