miR-615-3p promotes proliferation and migration and inhibits apoptosis through its potential target CELF2 in gastric cancer

Loss of CELF2 promotes skin tumorigenesis and increases drug resistance

BACKGROUND

CELF2 belongs to the CELF RNA-binding protein family and exhibits antitumor activity in various tumor models. Analysis of the pan-cancer TCGA database reveals that CELF2 expression strongly correlates with favorable prognosis among cancer patients. The function of CELF2 in nonmelanoma skin cancer has not been studied.

METHODS

We used shRNA-mediated knockdown (KD) of CELF2 expression in human squamous cell carcinoma (SCC) cells to investigate how CELF2 impacted SCC cell proliferation, survival, and xenograft tumor growth. We determined CELF2 expression in human SCC tissues and adjacent normal skin using immunofluorescence staining. Additionally, we investigated the changes in CELF2 and its target gene expression during UV-induced and chemical-induced skin tumorigenesis by western blotting.

RESULTS

CELF2 KD significantly increased SCC cell proliferation, colony growth, and SCC xenograft tumor growth in immunodeficient mice. CELF2 KD in SCC cells led to activation of KRT80 and GDF15, which can potentially promote cell proliferation and tumor growth. While control SCC cells were sensitive to anticancer drugs such as doxorubicin, SCC cells with CELF2 KD became resistant to drug-induced tumor growth retardation. Finally, we found CELF2 expression diminished during both UV- and chemical-induced skin tumorigenesis in mice, consistent with reduced CELF2 expression in human SCC tumors compared to adjacent normal skin.

CONCLUSION

This study shows for the first time that CELF2 loss occurs during skin tumorigenesis and increases drug resistance in SCC cells, highlighting the possibility of targeting CELF2-regulated pathways in skin cancer prevention and therapies.

Evaluating the pro-survival potential of apoptotic bodies derived from 2D- and 3D- cultured adipose stem cells in ischaemic flaps

In the realm of large-area trauma flap transplantation, averting ischaemic necrosis emerges as a pivotal concern. Several key mechanisms, including the promotion of angiogenesis, the inhibition of oxidative stress, the suppression of cell death, and the mitigation of inflammation, are crucial for enhancing skin flap survival. Apoptotic bodies (ABs), arising from cell apoptosis, have recently emerged as significant contributors to these functions. This study engineered three-dimensional (3D)-ABs using tissue-like mouse adipose-derived stem cells (mADSCs) cultured in a 3D environment to compare their superior biological effects against 2D-ABs in bolstering skin flap survival. The findings reveal that 3D-ABs (85.74 ± 4.51) % outperform 2D-ABs (76.48 ± 5.04) % in enhancing the survival rate of ischaemic skin flaps (60.45 ± 8.95) % (all p < 0.05). Mechanistically, they stimulated angiogenesis, mitigated oxidative stress, suppressed apoptosis, and facilitated the transition of macrophages from M1 to M2 polarization (all p < 0.05). A comparative analysis of microRNA (miRNA) profiles in 3D- and 2D-ABs identified several specific miRNAs (miR-423-5p-up, miR30b-5p-down, etc.) with pertinent roles. In summary, ABs derived from mADSCs cultured in a 3D spheroid-like arrangement exhibit heightened biological activity compared to those from 2D-cultured mADSCs and are more effective in promoting ischaemic skin flap survival. These effects are attributed to their influence on specific miRNAs.

UBE2C: A pan-cancer diagnostic and prognostic biomarker revealed through bioinformatics analysis

BACKGROUND

The diverse and complex attributes of cancer have made it a daunting challenge to overcome globally and remains to endanger human life. Detection of critical cancer-related gene alterations in solid tumor samples better defines patient diagnosis and prognosis, and indicates what targeted therapies must be administered to improve cancer patients' outcome.

MATERIALS AND METHODS

To identify genes that have aberrant expression across different cancer types, differential expressed genes were detected within the TCGA datasets. Subsequently, the DEGs common to all pan cancers were determined. Furthermore, various methods were employed to gain genetic alterations, co-expression genes network and protein-protein interaction (PPI) network, pathway enrichment analysis of common genes. Finally, the gene regulatory network was constructed.

RESULTS

Intersectional analysis identified UBE2C as a common DEG between all 28 types of studied cancers. Upregulated UBE2C expression was significantly correlated with OS and DFS of 10 and 9 types of cancer patients. Also, UBE2C can be a diagnostic factor in CESC, CHOL, GBM, and UCS with AUC = 100% and diagnose 19 cancer types with AUC ≥90%. A ceRNA network constructed including UBE2C, 41 TFs, 10 shared miRNAs, and 21 circRNAs and 128 lncRNAs.

CONCLUSION

In summary, UBE2C can be a theranostic gene, which may serve as a reliable biomarker in diagnosing cancers, improving treatment responses and increasing the overall survival of cancer patients and can be a promising gene to be target by cancer drugs in the future.

Elucidating the molecular basis of ATP-induced cell death in breast cancer: Construction of a robust prognostic model

BACKGROUND

Breast cancer is a multifaceted and formidable disease with profound public health implications. Cell demise mechanisms play a pivotal role in breast cancer pathogenesis, with ATP-triggered cell death attracting mounting interest for its unique specificity and potential therapeutic pertinence.

AIM

To investigate the impact of ATP-induced cell death (AICD) on breast cancer, enhancing our understanding of its mechanism.

METHODS

The foundational genes orchestrating AICD mechanisms were extracted from the literature, underpinning the establishment of a prognostic model. Simultaneously, a microRNA (miRNA) prognostic model was constructed that mirrored the gene-based prognostic model. Distinctions between high- and low-risk cohorts within mRNA and miRNA characteristic models were scrutinized, with the aim of delineating common influence mechanisms, substantiated through enrichment analysis and immune infiltration assessment.

RESULTS

The mRNA prognostic model in this study encompassed four specific mRNAs: P2X purinoceptor 4, pannexin 1, caspase 7, and cyclin 2. The miRNA prognostic model integrated four pivotal miRNAs: hsa-miR-615-3p, hsa-miR-519b-3p, hsa-miR-342-3p, and hsa-miR-324-3p. B cells, CD4+ T cells, CD8+ T cells, endothelial cells, and macrophages exhibited inverse correlations with risk scores across all breast cancer subtypes. Furthermore, Kyoto Encyclopedia of Genes and Genomes analysis revealed that genes differentially expressed in response to mRNA risk scores significantly enriched 25 signaling pathways, while miRNA risk scores significantly enriched 29 signaling pathways, with 16 pathways being jointly enriched.

CONCLUSION

Of paramount significance, distinct mRNA and miRNA signature models were devised tailored to AICD, both potentially autonomous prognostic factors. This study's elucidation of the molecular underpinnings of AICD in breast cancer enhances the arsenal of potential therapeutic tools, offering an unparalleled window for innovative interventions. Essentially, this paper reveals the hitherto enigmatic link between AICD and breast cancer, potentially leading to revolutionary progress in personalized oncology.

Role of CELF2 in ferroptosis: Potential targets for cancer therapy (Review)

Ferroptosis is a novel form of regulated cellular necrosis that plays a critical role in promoting cancer progression and developing drug resistance. The main characteristic of ferroptosis is iron‑dependent lipid peroxidation caused by excess intracellular levels of reactive oxygen species. CUGBP ELAV‑like family number 2 (CELF2) is an RNA‑binding protein that is downregulated in various types of cancer and is associated with poor patient prognoses. CELF2 can directly bind mRNA to a variety of ferroptosis control factors; however, direct evidence of the regulatory role of CELF2 in ferroptosis is currently limited. The aim of the present review was to summarise the findings of previous studies on CELF2 and its role in regulating cellular redox homeostasis. The present review may provide insight into the possible mechanisms through which CELF2 affects ferroptosis and to provide recommendations for future studies.

Integrated co-expression analysis of regulatory elements (miRNA, lncRNA, and TFs) in bovine monocytes induced by Str. uberis

Non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), together with transcription factors, are critical pre-, co-, and post-transcriptional regulators. In addition to their criteria as ideal biomarkers, they have great potential in disease prognosis, diagnosis, and treatment of complex diseases. Investigation of regulatory mechanisms in the context of bovine mastitis, as most common and economic disease in the dairy industry, to identify elements influencing the expression of candidate genes as key regulators of the mammary immune response is not yet fully understood. Transcriptome profiles (50 RNA-Seq and 50 miRNA-Seq samples) of bovine monocytes induced by Str. uberis were used for co-expression module detection and preservation analysis using the weighted gene co-expression network analysis (WGCNA) approach. Assigned mi-, lnc-, and m-modules used to construct the integrated regulatory networks and miRNA-lncRNA-mRNA regulatory sub-networks. Remarkably, we have identified 18 miRNAs, five lncRNAs, and seven TFs as key regulators of str. uberis-induced mastitis. Most of the genes introduced here, mainly involved in immune response, inflammation, and apoptosis, were new to mastitis. These findings may help to further elucidate the underlying mechanisms of bovine mastitis, and the discovered genes may serve as signatures for early diagnosis and treatment of the disease.

M2 macrophage-derived exosomal miR-1911-5p promotes cell migration and invasion in lung adenocarcinoma by down-regulating CELF2 -activated ZBTB4 expression

Lung adenocarcinoma (LUAD) is one of the most aggressive, lethal cancers, comprising around 40% of lung cancer cases. Metastases are the primary cause of LUAD deaths. The mechanism underlying metastatic LUAD and tumor microenvironment remain largely unknown. To explore the effect of M2 macrophage-derived exosomes on LUAD progression. Quantitative-PCR (q-PCR) and western blot were used to measure the expression of RNAs and proteins separately. Co-culture experiments wound healing and Transwell invasion assays were performed to evaluate the effect of M2 macrophage-derived exosomes on LUAD cell migration and invasion. RNA pulldown and luciferase reporter, RNA-binding immunoprecipitation (RIP), and mRNA stability assays were conducted to explore the downstream mechanism of exosomal microRNA-1911-5p (miR-1911-5p). M2 macrophage-derived exosomes accelerated the migration and invasion of LUAD cells. M2 macrophages-secreted exosomal miR-1911-5p enhanced cell migration and invasion in LUAD. Mechanically, miR-1911-5p targeted CUGBP- and ETR-3-like family 2 (CELF2) to downregulate zinc finger and BTB domain containing 4 (ZBTB4) in LUAD. Additionally, miR-1911-5p promoted LUAD progression via ZBTB4. The present study demonstrated that M2 macrophage-derived exosomal miR-1911-5p facilitates the migration and invasion of LUAD cells by inhibiting CELF2-activated ZBTB4, which might offer insight into LUAD treatment.

Lymphatic Dissemination in Prostate Cancer: Features of the Transcriptomic Profile and Prognostic Models

Radical prostatectomy is the gold standard treatment for prostate cancer (PCa); however, it does not always completely cure PCa, and patients often experience a recurrence of the disease. In addition, the clinical and pathological parameters used to assess the prognosis and choose further tactics for treating a patient are insufficiently informative and need to be supplemented with new markers. In this study, we performed RNA-Seq of PCa tissue samples, aimed at identifying potential prognostic markers at the level of gene expression and miRNAs associated with one of the key signs of cancer aggressiveness-lymphatic dissemination. The relative expression of candidate markers was validated by quantitative PCR, including an independent sample of patients based on archival material. Statistically significant results, derived from an independent set of samples, were confirmed for miR-148a-3p and miR-615-3p, as well as for the CST2, OCLN, and PCAT4 genes. Considering the obtained validation data, we also analyzed the predictive value of models based on various combinations of identified markers using algorithms based on machine learning. The highest predictive potential was shown for the "CST2 + OCLN + pT" model (AUC = 0.863) based on the CatBoost Classifier algorithm.

CD44v3 is a marker of invasive cancer stem cells driving metastasis in gastric carcinoma

BACKGROUND

Cancer stem cells (CSCs) are at the origin of tumour initiation and progression in gastric adenocarcinoma (GC). However, markers of metastasis-initiating cells remain unidentified in GC. In this study, we characterized CD44 variants expressed in GC and evaluated the tumorigenic and metastatic properties of CD44v3+ cells and their clinical significance in GC patients.

METHODS

Using GC cell lines and patient-derived xenografts, we evaluated CD44+ and CD44v3+ GC cells molecular signature and their tumorigenic, chemoresistance, invasive and metastatic properties, and expression in patients-derived tissues.

RESULTS

CD44v3+ cells, which represented a subpopulation of CD44+ cells, were detected in advanced preneoplastic lesions and presented CSCs chemoresistance and tumorigenic properties in vitro and in vivo. Molecular and functional analyses revealed two subpopulations of gastric CSCs: CD44v3+ CSCs with an epithelial-mesenchymal transition (EMT)-like signature, and CD44+/v3- CSCs with an epithelial-like signature; both were tumorigenic but CD44v3+ cells showed higher invasive and metastatic properties in vivo. CD44v3+ cells detected in the primary tumours of GC patients were associated with a worse prognosis.

CONCLUSION

CD44v3 is a marker of a subpopulation of CSCs with metastatic properties in GC. The identification of metastasis-initiating cells in GC represents a major advance for further development of anti-metastatic therapeutic strategies.

CircLIFR Inhibits Non-small Cell Lung Cancer Progression by Acting as a miR-429 Sponge to Enhance CELF2 Expression

Lung cancer is the most commonly diagnosed cancer and the leading reason for tumor-related mortality, while non-small cell lung cancer (NSCLC) is the most usual type of lung cancer. Circular RNAs (circRNAs) have emerged as vital regulators in the development of human cancers, including NSCLC. We aimed to explore the functions of circRNA leukemia inhibitory factor receptor (circLIFR) in NSCLC progression. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to quantify the expression of circLIFR, microRNA-429 (miR-429), and Elav-like family member 2 (CELF2) in NSCLC tissues and cells. Cell proliferation capability of NSCLC cells was determined by Cell Counting Kit-8 (CCK-8) and colony formation assays. The flow cytometry assay was performed to evaluate cell-cycle distribution and apoptosis of NSCLC cells. The abilities of migration and invasion were measured by transwell assay. In addition, the activities of caspase 3 and caspase 9 were measured by the assay kits. The interaction relationship between miR-429 and circLIFR or CELF2 was analyzed by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. The expression levels of related proteins were examined by Western Blot assay. The xenograft experiment was established to explore the role of circLIFR in vivo. CircLIFR, circular, and stable transcript in NSCLC cells, was decreased more than 2 folds in NSCLC tissues and cells than controls (P < 0.0001). Importantly, overexpression of circLIFR impeded cell proliferation, migration, invasion, and inactivated protein kinase B (AKT)/phosphatase and tensin homolog (PTEN)-signaling pathways while enhanced apoptosis and cell-cycle arrest in NSCLC cells, which was overturned by upregulation of miR-429 or silencing of CELF2. Furthermore, the upregulation of circLIFR inhibited NSCLC tumor growth in vivo. Overexpression of circLIFR could suppress NSCLC progress by acting as a sponge of miR-429 to regulate the expression of CELF2 and PTEN/AKT-signaling pathways in NSCLC.

MiR-210-3p targets CELF2 to facilitate progression of lung squamous carcinoma through PI3K/AKT pathway

This study examined the internal mechanism of miR-210-3p/CELF2 in LUSC. Expression data of mRNAs and miRNAs in LUSC were acquired from TCGA and subjected to differential expression analysis. qRT-PCR was applied to examine miR-210-3p and CELF2 expression. Besides, western blot was utilized to evaluate protein expression of CELF2 and PI3K/AKT pathway-related proteins. Dual-luciferase reporter analysis was conducted to validate targeting relationship between miR-210-3p and CELF2. Additionally, CCK-8, colony formation, transwell and flow cytometry were employed to respectively test proliferation, migration, invasion abilities and cell cycle distribution. Xenograft tumor models were used to evaluate the influence of miR-210-3p and CELF2 on tumor growth. MiR-210-3p was highly expressed, while CELF2 was less expressed in LUSC cells. Besides, miR-210-3p could downregulate CELF2 expression. Cell functional assay verified that miR-210-3p accelerated aggressive behaviors of LUSC cells. Additionally, rescue assay suggested that miR-210-3p downregulated CELF2 level to stimulate LUSC cell phenotypes and cell cycle progression through PI3K/AKT pathway. Moreover, miR-210-3p/CELF2 stimulated the tumor growth in vivo. To sum up, miR-210-3p modulated CELF2 expression, thus affecting cell phenotypes and cell cycle distribution in LUSC through PI3K/AKT pathway.

LncRNA4474 inhibits renal fibrosis by regulating hepatocyte nuclear factor-1β through miR-615 modulation

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in the development and progression of renal fibrosis. lncRNAs can regulate target messenger RNAs (mRNAs) by competitively binding to miRNAs. However, research on lncRNA-miRNA-mRNA interactions remains inadequate. Therefore, the aim of the present study was to investigate the possible function of lncRNA-miRNA-mRNA interactions in chronic renal fibrosis. The relationships among the expression levels of lncRNA4474, miR-615, and hepatocyte nuclear factor-1β (HNF-1β) mRNAs were determined through RNA sequencing. The biological roles of lncRNA4474, miR-615, and HNF-1β in renal fibrosis were investigated with gain-of-function and loss-of-function experiments. Results showed that miR-615 expression increased in unilateral ureteral obstruction rats, accompanied by decreased lncRNA4474 and HNF-1β mRNA expression. The overexpression of HNF-1β attenuated the development of chronic renal fibrosis, whereas HNF-1β knockdown promoted the development. Increase in HNF-1β expression downregulated and upregulated the expression levels of miR-615 and lncRNA4474, respectively, thereby attenuating renal fibrosis progression. Furthermore, lncRNA4474 promoted the expression of HNF-1β by inhibiting miR-615 expression, whereas miR-615 regulated the expression of HNF-1β and thus activated the Wnt signaling pathway. This study demonstrated that the overexpression of lncRNA4474 may attenuate fibrosis progression, accompanied by the downregulation of miR-615 and upregulation of HNF-1β. Hence, this study provides novel information that can be useful in the early diagnosis and treatment of renal fibrosis.

Comprehensive analysis of competitive endogenous RNAs network: Identification and validation of prediction model composed of mRNA signature and miRNA signature in gastric cancer

Gastric cancer (GC), one of the most lethal malignant tumors, is highly aggressive with a poor prognosis, while the molecular mechanisms underlying it remain largely unknown. Although advanced imaging techniques and comprehensive treatment facilitate the diagnosis and survival of some GC patients, the precise diagnosis and prognosis are still a challenge. The present study used publicly available gene expression profiles from The Cancer Genome Atlas and Gene Expression Omnibus datasets including mRNA, micro (mi)RNA and circular (circ)RNA of GC to establish a competing endogenous RNA network (ceRNA). Further, the present study performed least absolute shrinkage and selector operator regression analysis on the hub RNAs to establish a prediction model with mRNA and miRNA. The ceRNA network contained 109 edges and 56 nodes and the visible network contains 13 miRNAs, 9 circRNAs and 34 mRNAs. The five mRNA-based signature were CTF1, FKBP5, RNF128, GSTM2 and ADAMTS1. The area under curve (AUC) value of the diagnosis training cohort was 0.9975. The prognosis of the high-risk group (RiskScore >4.664) was worse compared with that of the low-risk group (RiskScore ≤4.664; P<0.05) in the training cohort. The five miRNA-based signature were miR-145-5p, miR-615-3p, miR-6507-5p, miR-937-3p and miR-99a-3p. The AUC value of the diagnosis training cohort was 0.9975. The prognosis of the high-risk group (RiskScore >1.621) was worse compared with that of the low-risk group (RiskScore ≤1.621; P<0.05) in the training cohort. The validation cohorts indicated that both five mRNA and five miRNA-based signatures had strong predictive power in diagnosis and prognosis for GC. In conclusion, a ceRNA network was established for GC and a five mRNA-based signature and a five miRNA-based signature was identified that enabled diagnosis and prognosis of GC by assigning patient to a high-risk group or low-risk group.

MicroRNA‑4722‑5p and microRNA‑615‑3p serve as potential biomarkers for Alzheimer's disease

The aim of the present study was to investigate the expression levels of microRNA(miR)-4722-5p and miR-615-3p in Alzheimer's disease (AD) and their diagnostic value. Blood samples were collected from 33 patients with AD and 33 healthy controls, and an β-amyloid (Aβ)25-35-induced PC12 cell model was also established. The relative mRNA expression levels of miR-4722-5p and miR-615-3p were detected using reverse transcription-quantitative PCR. The correlations between the mRNA expression levels of the two miRNAs and the mini-mental state examination (MMSE) scores were analyzed, and the receiver operating characteristic curve was used to assess the diagnostic value of miR-4722-5p and miR-615-3p in AD. Functional enrichment analysis of the miRNA target genes was performed using The Database for Annotation, Visualization and Integrated Discovery database and the R language analysis package. The mRNA expression levels of miR-4722-5p and miR-615-3p were increased in patients with AD and the Aβ25-35-induced PC12 cell model. The mRNA expression levels of miR-4722-5p and miR-615-3p were negatively correlated with MMSE scores, and the combination of the two miRNAs for AD had an improved diagnostic value than that of each miRNA alone. The results of Gene Ontology (GO) enrichment analysis showed that the target genes of miR-4722-5p were found in the cytoplasm and cytosol, and were mainly involved in protein folding and cell division. The molecular functions included protein binding and GTPase activator activity. The results of Kyoto Encyclopedia of Genes and Genomes analysis showed that miR-4722-5p was associated with the regulation of dopaminergic synapses and mTOR signaling pathways. GO enrichment analysis also revealed that the target genes of miR-615-3p were located in the nucleus and cytoplasm, were involved in the regulation of transcription and protein phosphorylation, and were associated with protein binding, metal ion binding and transcription factor activity. The target genes of miR-615-3p played important roles in the regulation of the Ras and FoxO signaling pathways. In conclusion, miR-4722-5p and miR-615-3p may be potential biomarkers in the early diagnosis of AD.

NOVA1-Mediated SORBS2 Isoform Promotes Colorectal Cancer Migration by Activating the Notch Pathway

Background: Gene expression and alternative splicing (AS) can promote cancer development via complex mechanisms. We aimed to identify and verify the hub AS events and splicing factors associated with the progression of colorectal cancer (CRC).

Methods: RNA-Seq data, clinical data, and AS events of 590 CRC samples were obtained from the TCGA and TCGASpliceSeq databases. Cox univariable and multivariable analyses, KEGG, and GO pathway analyses were performed to identify hub AS events and splicing factor/spliceosome genes, which were further validated in five CRCs.

Results: In this study, we first compared differentially expressed genes and gene AS events between normal and tumor tissues. Differentially expressed genes were different from genes with differentially expressed AS events. Prognostic analysis and co-expression network analysis of gene expression and gene AS events were conducted to screen five hub gene AS events involved in CRC progression: EPB41L2, CELF2, TMEM130, VCL, and SORBS2. Using qRT-PCR, we also verified that the gene AS events SORBS2 were downregulated in tumor tissue, and gene AS events EPB41L2, CELF2, TMEM130, and VCL were upregulated in tumor tissue. The genes whose mRNA levels were significantly related to the five hub gene AS events were significantly enriched in the GO term of cell division and Notch signaling pathway. Further coexpression of gene AS events and alternative splicing factor genes revealed NOVA1 as a crucial factor regulating the hub gene AS event expression in CRC. Through in vitro experiments, we found that NOVA1 inhibited gene AS event SORBS2, which induced the migration of CRC cells via the Notch pathway.

Conclusion: Integrated analysis of gene expression and gene AS events and further experiments revealed that NOVA1-mediated SORBS2 promoted the migration of CRC, indicating its potential as a therapeutic target.

CELF Family Proteins in Cancer: Highlights on the RNA-Binding Protein/Noncoding RNA Regulatory Axis

Post-transcriptional modifications to coding and non-coding RNAs are unquestionably a pivotal way in which human mRNA and protein diversity can influence the different phases of a transcript's life cycle. CELF (CUGBP Elav-like family) proteins are RBPs (RNA-binding proteins) with pleiotropic capabilities in RNA processing. Their responsibilities extend from alternative splicing and transcript editing in the nucleus to mRNA stability, and translation into the cytoplasm. In this way, CELF family members have been connected to global alterations in cancer proliferation and invasion, leading to their identification as potential tumor suppressors or even oncogenes. Notably, genetic variants, alternative splicing, phosphorylation, acetylation, subcellular distribution, competition with other RBPs, and ultimately lncRNAs, miRNAs, and circRNAs all impact CELF regulation. Discoveries have emerged about the control of CELF functions, particularly via noncoding RNAs, and CELF proteins have been identified as competing, antagonizing, and regulating agents of noncoding RNA biogenesis. On the other hand, CELFs are an intriguing example through which to broaden our understanding of the RBP/noncoding RNA regulatory axis. Balancing these complex pathways in cancer is undeniably pivotal and deserves further research. This review outlines some mechanisms of CELF protein regulation and their functional consequences in cancer physiology.

Splice and Dice: Intronic microRNAs, Splicing and Cancer

Introns span only a quarter of the human genome, yet they host around 60% of all known microRNAs. Emerging evidence indicates the adaptive advantage of microRNAs residing within introns is attributed to their complex co-regulation with transcription and alternative splicing of their host genes. Intronic microRNAs are often co-expressed with their host genes, thereby providing functional synergism or antagonism that is exploited or decoupled in cancer. Additionally, intronic microRNA biogenesis and the alternative splicing of host transcript are co-regulated and intertwined. The importance of intronic microRNAs is under-recognized in relation to the pathogenesis of cancer.

A novel 13 RNA binding proteins (RBPs) signature could predict prostate cancer biochemical recurrence

BACKGROUND

Cancer precision medicine requires biomarkers or signatures to predict prognosis and therapeutic benefits. Driven by this, we established a biochemical recurrence (BCR) predictive model for prostate cancer (PCA) patients based on RNA-binding proteins (RBPs).

METHODS

RNA-sequencing and corresponding clinicopathological data were downloaded from the Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database. Univariate COX, LASSO and multivariate COX regression analyses were carried out to develop the BCR predictive riskScore model. Survival analysis, ROC curve, independent prognostic analysis, nomogram were also performed to evaluate this signature internally and externally.

RESULTS

A total of 13 RBPs including TRMT1L, WBP4, MBNL3, SMAD9, NSUN7, ENG9, PIWIL4, PEG10, CSDC2, HELZ2, CELF2, YBX2 and ESRP2 were eventually identified as BCR-related hub biomarkers and utilized to establish a riskScore. Further analysis including external and internal verification indicated that the patients with high riskScores had shorter time to BCR compared to those with low riskScores in both TCGA and GSE116918. The area under the curve (AUC) of the time-dependent receiver operator characteristic curve (ROC) of the predictive model exhibited a good predictive performance. The signature was also proven to be a valuable independent prognostic factor (all P < 0.05). We also established a nomogram based on the 13 RBPs to visualize the relationships between individual predictors and 1-, 3- and 5-year BCR for PCA.

CONCLUSIONS

Our results successfully screened out 13 RBPs as a robust BCR-predictive signature in PCA by external and internal verification, helping clinician predict patients' cancer progression status and promoting the specific individualized treatment than original clinical parameters.

LncRNA RHPN1-AS1 promotes the progression of nasopharyngeal carcinoma by targeting CELF2 expression

This study aims to investigate the role of lncRNA RHPN1-AS1 in NPC and its potential regulatory mechanism. The expression of RHPN1-AS1 in tissues and cells was measured by qRT-PCR. The effect of RHPN1-AS1 silencing on biological functions of NPC cells was detected by CCK-8, colony formation, flow cytometry, wound healing, and transwell assays. The protein expression was measured by western blot. The RBPs of RHPN1-AS1 were predicted by Starbase and LncTar, and verify by RIP assay. ESTIMATE was used to analyze the relationship between CELF2 expression and tumor purity. GSEA was used to analyze the downstream signaling pathway of CELF2. In our study, RHPN1-AS1 was up-regulated in NPC tissues and cells. RHPN1-AS1 silencing inhibited cell viability, capacity of proliferation, migration and invasion, promoted apoptosis, decreased protein expression of Bcl-2, MMP2/9, increased protein expression of Bax, caspase-3, and TIMP2 of NPC cells. CELF2 was a target of RHPN1-AS1 and was down-regulated in NPC tissues and cells. CELF2 level was associated with tumor purity negatively. Low expression of CELF2 activated mTORC1 signaling pathway and increased protein expression of p-mTORC1/mTORC1 and p-P70S6K/P70S6K. RHPN1-AS1 silencing eliminated the activating effect of CELF2 silencing on mTORC1 signaling pathway. Moreover, CELF2 silencing reversed the inhibitory effect of RHPN1-AS1 on NPC progression. In conclusion, our findings indicated that RHPN1-AS1 plays an important role in NPC via activating mTORC1 signaling which is modulated by CELF2. RHPN1-AS1 may serve as a potential therapeutic target for NPC treatment.

CELF2 is a candidate prognostic and immunotherapy biomarker in triple-negative breast cancer and lung squamous cell carcinoma: A pan-cancer analysis

CUGBP Elav‐like family member 2(CELF2) plays crucial roles in the development and activation of T cell. However, the impacts of CELF2 on tumour‐infiltrating immune cells (TIICs) and clinical outcomes of tumours remain unclear. In this study, we found that elevated CELF2 expression was markedly correlated with prolonged survival in multiple tumours, particularly in breast and lung cancers. Notably, CELF2 only impacted the prognosis of triple‐negative breast cancer (TNBC) with lymph node metastasis. Further investigation showed CELF2 expression was positively correlated with the infiltration abundance of dendritic cells (DCs), CD8+ T cells and neutrophils in breast invasive carcinoma (BRCA) and DCs in lung squamous cell carcinoma (LUSC). CELF2 also had strong correlations with markers of diverse TIICs such as T cells, tumour‐associated macrophages and DCs in BRCA and LUSC. Importantly, CELF2 was significantly associated with plenty of immune checkpoint molecules (ICMs) and outperformed five prevalent biomarkers including PD‐1, PD‐L1, CTLA‐4, CD8 and tumour mutation burden in predicting immunotherapeutic responses. Immunohistochemistry also revealed lower protein levels of CELF2 in TNBC and LUSC compared to normal tissues, and patients with high expression showed significantly prolonged prognosis. In conclusion, we demonstrated that increased CELF2 expression was closely related to better prognosis and superior TIIC infiltration and ICM expression, particularly in BRCA and LUSC. CELF2 also performed well in evaluating the immunotherapeutic efficacy, suggesting CELF2 might be a promising biomarker.

Suppression of miR-106a-5p expression inhibits tumorigenesis via increasing CELF-2 expression in spinal cord glioma

Spinal cord glioma is a tumor characterized by high recurrence and mortality rates, and its treatment remains a major challenge. It has been reported that abnormal expression of microRNAs (miRNAs/miRs) is associated with tumor progression. Therefore, the current study aimed to identify novel miRNAs associated with spinal cord glioma. Herein, the expression levels of several miRNAs were determined in human spinal cord glioma and adjacent non-cancerous tissues by reverse transcription-quantitative (RT-qPCR). The results revealed that miR-106a-5p expression was markedly upregulated in spinal cord glioma tissues compared with in non-cancerous tissues. Furthermore, the biological effects of miR-106a-5p on spinal cord glioma cells were evaluated by MTT, Transwell and flow cytometric assays. In 0231SCG cells transfected with miR-106a-5p inhibitor, cell proliferation, migration and invasion were attenuated, whereas apoptosis was enhanced. A search of the TargetScan database revealed that miR-106a-5p directly targeted CUGBP Elav-like family member 2 (CELF-2). Western blot and RT-qPCR experiments further confirmed the association between miR-106a-5p and CELF-2 expression in spinal cord glioma tissues. The current results demonstrated that CELF-2 was a direct target of miR-106a-5p, and that the expression levels of CELF-2 were negatively associated with those of miR-106a-5p. In addition, overexpression of CELF-2 in spinal cord glioma cells reversed the tumor-promoting effects of miR-106a-5p both in vitro and in vivo. Overall, the aforementioned findings indicated that miR-106a-5p, which was highly expressed in spinal cord glioma tissues, may affect the proliferation, migration, invasion and apoptosis of spinal cord glioma cells via targeting CELF-2, thus indicating a potential approach to the future clinical management of spinal cord glioma.

RNA-binding protein CELF2 inhibits breast cancer cell invasion and angiogenesis by downregulating NFATc1

Breast cancer constitutes a major cause of morbidity and mortality among women in China and worldwide. The aim of the present study was to investigate whether CUGBP Elav-like family member 2 (CELF2) could inhibit breast cancer cell invasion and angiogenesis by downregulating nuclear factor of activated T cells 1 (NFATc1) expression. The expression of CELF2 and NFATc1 in breast cancer cells and tissues was detected by reverse transcription-quantitative PCR analysis. H&E staining was used to assess the number of microvessels in tumor tissue. The expression of proteins associated with invasion and angiogenesis and NFATc1 in tumor tissues and transfected cells was examined by western blotting. RNA pull-down assay was used to verify the interaction between CELF2 and NFATc1. Cell proliferation, invasion and tube-forming ability was analyzed using Cell Counting Kit-8, Transwell and HUVEC tube formation assays, respectively. CELF2 expression was found to be decreased in breast cancer cells, whereas CELF2 overexpression suppressed the proliferation and invasion of breast cancer cells and inhibited tumor growth and angiogenesis. Furthermore, CELF2 overexpression decreased the expression of N-cadherin (N-cad), CD34 and NFATc1 in tumor tissues, whereas NEAFc1 overexpression increased the expression of N-cad and NFATc1 in MCF cells transfected with OverExp-CELF2. CELF2 was found to be inversely associated with NFATc1, and NFATc1 overexpression reversed the effects of CELF2 overexpression. In conclusion, the findings of the present study demonstrated that CELF2 may inhibit breast cancer cell invasion and angiogenesis by downregulating NFATc1.

Hypoxic colorectal cancer-secreted exosomes deliver miR-210-3p to normoxic tumor cells to elicit a protumoral effect

Hypoxia, the most common feature in the tumor microenvironment, is closely related to tumor malignant progression and poor patient's prognosis. Exosomes, initially recognized as cellular "garbage dumpsters", are now known to be important mediums for mediating cellular communication in tumor microenvironment. However, the mechanisms of hypoxic tumor cell-derived exosomes facilitate colorectal cancer progression still need further exploration. In the present study, we found that exosomes from hypoxic colorectal cancer cells (H-Exos) promoted G1-S cycle transition and proliferation while preventing the apoptosis of colorectal cancer cells by transmitting miR-210-3p to normoxic tumor cells. Mechanistic investigation indicated that miR-210-3p from H-Exos elicited its protumoral effect via suppressing CELF2 expression. A preclinical study further confirmed that H-Exos could promote tumorigenesis in vivo. Clinically, the expression of miR-210-3p in circulating plasma exosomes was markedly upregulated in colorectal cancer patients, which were closely associated with multiple unfavorable clinicopathological features. Taken together, these results suggest that hypoxia may stimulate colorectal cancer cells to secrete miR-210-3p-enriched exosomes in tumor microenvironment, which elicit protumoral effects by inhibiting CELF2 expression. These findings provide new insights on the mechanism of colorectal cancer progression and potential therapeutic targets for colorectal cancer.

S100P acts as a target of miR-495 in pancreatic cancer through bioinformatics analysis and experimental verification

S100 calcium binding protein P (S100P) and miR-495 are aberrantly expressed and exert essential roles in cancers. However, the mechanisms of miR-495-S100P in pancreatic cancer are yet to be illustrated. Thus, we explored the regulatory functions of miR-495-S100P axis in pancreatic adenocarcinoma cells growth and invasion. In this study, we identified that S100P was upregulated in pancreatic adenocarcinoma by bioinformatics analysis of the GEO (Gene Expression Omnibus database) microarray dataset (GSE16515). Western blotting and luciferase reporter gene analysis exhibited that miR-495 negatively determined the level of S100P via binging to its 3'-untranslated regions (3'-UTRs). A series of functional experiments indicated that upregulation of miR-495 or S100P knockdown suppressed pancreatic adenocarcinoma cells proliferation, invasion, and promoted apoptosis. Furthermore, the expression of S100P was negatively associated with the level of miR-495 in The Cancer Genome Atlas (TCGA) pancreatic adenocarcinoma case-cohort. Besides, reintroduction of S100P debilitated the anti-cancer action of miR-495 in pancreatic adenocarcinoma cells. Our data indicated that miR-495 performed suppressive roles in pancreatic adenocarcinoma through targeting S100P.

Integrative network analysis revealed molecular mechanisms of urine urea output in lactating dairy cows: Potential solutions to reduce environmental nitrate contamination

BACKGROUND

The enriched nitrogenous compounds in the dairy farms negatively affect the surrounding soil quality and air condition. The objective of this study is to investigate the transcriptomes of five key tissues involved in nitrogen metabolism and their changes under different diets to elucidate the molecular regulatory mechanisms of urine urea nitrogen (UUN) yield, one of the indicators of nitrogenous compound secretion of dairy cows.

RESULTS

Cows fed high quality forage-based diet had lower UUN content and UUN yield, compared to those fed low quality forage (crop byproducts) based diets. From the transcriptomes of rumen, duodenum, jejunum, liver and udder, key driver genes and their UUN yield-associated functional gene networks were identified. In addition, the functional networks and expression of key drivers in various tissues (such as S100A8, CA1 and BPIFA2C in the duodenum; A2ML1, HMGCS2 and S100A12 in the jejunum; CYP2B6 and GLYCAM1 in the liver; APOE in the udder) changed in the cows fed crop byproducts based diet, which might be the predominant molecules to drive the increase UUN yield in these cows.

CONCLUSION

The information suggested that gut, liver and udder play important roles in regulating UUN yield, which could regulate nitrogen excretion waste. These findings provide fundamental information on future nutritional intervention strategies to reduce the UUN yield from dairy cows fed human inedible crop byproducts, which is vital for a sustainable and environmentally friendly dairy industry.

The RNA-Binding Protein CELF2 Inhibits Ovarian Cancer Progression by Stabilizing FAM198B

An increasing number of studies have clarified the functional roles of RNA-binding proteins (RBPs) in driving post-transcriptional mechanisms of cancer progression. In this study, we integrated data from the RBP database and Gene Expression Omnibus (GEO) data with RNA sequencing (RNA-seq) data from 10 ovarian cancer tissues and 8 normal ovarian tissues and identified an RBP, CUGBP- and ETR-3-like family 2 (CELF2). We found that CELF2 expression was downregulated in ovarian cancer and positively correlated with the overall survival (OS) and progression-free survival (PFS) of patients with ovarian cancer. Altered CELF2 expression led to changes in the proliferation, migration, and invasion of ovarian cancer cells in vitro and in vivo. CELF2 expression increased the stability of its target, FAM198B, by binding to AU/U-rich elements (AREs) in the 3' untranslated region (3' UTR). FAM198B knockdown restored the CELF2-mediated suppression of proliferation and migration. We also found that CELF2/FAM198B may repress ovarian cancer progression by inhibiting the mitogen-activated protein kinase/extracellular-regulated protein kinase (MAPK/ERK) signaling pathway. Finally, a curcumin-induced increase in CELF2 expression resulted in increased ovarian cancer cell sensitivity to cisplatin. Our study elucidated a novel mechanism by which the CELF2/FAM198B axis regulates proliferation and metastasis in ovarian cancer, providing novel, potential therapeutic targets for ovarian cancer.

MicroRNA-1301-3p promotes the progression of non-small cell lung cancer by targeting Thy-1 and predicts poor prognosis of patients

The role of microRNA (miR)-1301-3p has been investigated in breast cancer and colorectal cancer. Dysregulation of miR-1301-3p expression in non-small cell lung cancer (NSCLC) is speculated to be associated with tumor progression, which was systemically investigated in the present study. Reverse transcription-quantitative PCR analysis was performed to detect miR-1301-3p expression in 124 paired tissue samples and cultured cell lines. The results demonstrated that miR-1301-3p expression was regulated by transfection with miR-1301-3p mimic or inhibitor, and the proliferation, migration and invasion of the transfected cells were assessed via the Cell Counting Kit-8 and Transwell assays. In addition, miR-1301-3p expression was significantly upregulated in NSCLC tissues and cells compared with normal tissues and normal cells, respectively. Notably, upregulated miR-1301-3p expression in NSCLC tissues was significantly associated with the TNM stage, lymph node metastasis and poor prognosis of patients with NSCLC. Furthermore, upregulated miR-1301-3p expression in NSCLC cells promoted cell proliferation, migration and invasion, the effects of which were reversed following miR-1301-3p knockdown. Thy-1 was identified as a direct target of miR-1301-3p, which serves as a tumor promoter in the progression of NSCLC. Taken together, the results of the present study suggest that upregulated miR-1301-3p expression in NSCLC acts as an independent prognostic factor and a tumor promoter by targeting thy-1, thus provides a potential therapeutic target for NSCLC.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

M2 macrophage-derived G-CSF promotes trophoblasts EMT, invasion and migration via activating PI3K/Akt/Erk1/2 pathway to mediate normal pregnancy

Trophoblasts are important parts of the placenta and exert vital roles in the maternal-foetal crosstalk, and sufficient trophoblasts migration and invasion is critical for embryo implantation and normal pregnancy. Macrophages, as the major components of decidual microenvironment at maternal-foetal interface, can interact with trophoblasts to participate in the regulation of normal pregnancy. Previously, our group have demonstrated that trophoblasts could induce macrophages polarization to M2 subtype by secreting interleukin-6 (IL-6); however, the understanding of macrophages regulating the migration and invasion of trophoblasts is limited. In the present study, we used the co-cultured model to further investigate the effects of macrophages on trophoblasts migration and invasion. Our results showed that co-culture with macrophages promoted epithelial-to-mesenchymal transition (EMT) of trophoblasts, thereby enhancing their migrative and invasive abilities. Further experiments revealed that M2 macrophage-derived G-CSF was a key factor, which promoted the EMT, migration and invasion of trophoblasts via activating PI3K/Akt/Erk1/2 signalling pathway. Clinically, G-CSF was highly expressed in placental villous tissues of normal pregnancy patients compared to patients with recurrent spontaneous abortion, and its expression level was significantly correlation with EMT markers. Taken together, these findings indicate the important role of M2 macrophages in regulating trophoblasts EMT, migration and invasion, contributing to a new insight in concerning the crosstalk between macrophages and trophoblasts in the establishment and maintenance of normal pregnancy.

Long noncoding RNA GAS5 ameliorates chronic constriction injury induced neuropathic pain in rats by modulation of the miR-452-5p/CELF2 axis

Neuropathic pain is a type of spontaneous pain that causes damage to the central nervous system. Long noncoding RNAs (lncRNAs) participate in the progression of various nervous system diseases, including neuropathic pain. However, the biological function of GAS5 in neuropathic pain remains unclear. Our findings revealed that GAS5 was downregulated in chronic constriction injury (CCI) rats. Besides, ELISA showed that the concentration of IL-6, TNF-α, and IL-1β were reduced by overexpressed GAS5 in spinal cord homogenates of CCI rats. Moreover, mechanical allodynia and thermal hyperalgesia in CCI rats were inhibited by GAS5 overexpression, suggesting that GAS5 overexpression attenuated neuropathic pain. Subsequently, we found that GAS5 served as a sponge for miR-452-5p in CCI rats and CELF2 was the downstream target of miR-452-5p. Finally, through a rescue assay, we found that GAS5 ameliorated neuropathic pain in CCI rats by sponging miR-452-5p to regulate CELF2 expression. Our study confirmed that GAS5 ameliorated neuropathic pain in rats by modulation of the miR-452-5p/CELF2 axis, which may provide some clues for neuropathic pain treatment.

Evaluating the effect of ovarian stimulation and exogenous progesterone on CD31-positive cell density, VEGF protein, and miR-17-5p expression of endometrium immediately before implantation

BACKGROUND

MicroRNAs (miRNAs) form a special class of RNAs regulating endometrial functions like cell proliferation, differentiation, angiogenesis, and blastocyst implantation. In addition to providing suitable conditions for embryo development, angiogenesis is a prerequisite to natural pregnancy. The family of vascular endothelial growth factor (VEGF) and its receptors are the main physiological and pathological angiogenesis regulators in the endometrium. In the past, research has demonstrated alteration of angiogenesis and subsequent endometrial receptivity in the stimulated and luteal phase support cycles, when compared with natural cycles.

OBJECTIVE

The objective of this study is to investigate the effect of ovarian stimulation and exogenous progesterone on the density of CD31-positive cell (Endothelial cell), VEGF protein, and miR-17-5p expression in the mouse endometrium immediately before implantation.

METHODS

We employed ovarian stimulated and luteal phase support mice models induced by HMG/HCG and progesterone. The endometrial CD31-positive cell density was determined by immunohistochemistry (IHC) staining, the level of VEGF protein by IHC and western blot analysis, and finally the miR-17-5p expression was determined by the real-time PCR method.

RESULTS

The density of endothelial cell, VEGF protein, and miR-17-5p expression increased in all of the experimental mice when compared to the control group, with the maximum increase having been seen in the group that had received progesterone after ovarian stimulation.

CONCLUSION

This research indicates that ovarian stimulation and exogenous progesterone lead to an increase in the number of endothelial cells by upregulating the VEGF protein. Moreover, except for miR-17-5p, other microRNAs and molecules are presumably involved in angiogenic pathways, thereby requiring more studies.

First Whole Transcriptome RNAseq on CHD8 Haploinsufficient Patient and Meta-Analyses Across Cellular Models Uncovers Likely Key Pathophysiological Target Genes

In 2019, we confirmed that the haploinsufficiency of CHD8 does indeed cause the novel syndromic neurodevelopmental disease we first discovered a dozen years before. Here, we report the first whole transcriptome RNAseq gene expression profiling for a patient with this new syndrome, as a preliminary exploration of potential pathophysiological mechanisms. We compared our patient transcriptome profile with that of all publicly available RNAseq datasets from human cellular models including neuronal progenitor cells, neurons and organoids. We compared differential gene expression profiles overall and conducted phenotype-informed data filtration based on the characteristic syndrome presentation. We found that concordance among differential gene expression profiles was poor across all datasets. Nevertheless, remarkably, we show that the patient blood differential gene expression profile most resembled that of the neuronal cell model, a finding that encourages further transcriptome profiling using patient blood samples. In addition, our custom phenotype-informed analyses yielded important, differentially expressed syndrome pathophysiology target genes. Finally, we note that genes dysregulated due to CHD8 heterozygous deletion are linked to known neurological as well as oncological pathways.

Circ_0032821 Facilitates Gastric Cancer Cell Proliferation, Migration, Invasion and Glycolysis by Regulating MiR-1236-3p/HMGB1 Axis

Background

Circular RNAs (circRNAs) play an essential role in the pathogenesis of malignant tumors, including gastric cancer (GC). However, the effect of circ_0032821 on GC remains largely unknown.

Methods

QRT-PCR assay was employed to examine the levels of circ_0032821, CEP128 mRNA and miR-1236-3p. RNase R digestion assay was utilized to verify the feature of circ_0032821. Cell Counting Kit-8 (CCK-8) assay and transwell assay were adopted to evaluate cell proliferation and metastasis. The level of glycolysis was evaluated through detecting ECAR, OCR, lactate production, glucose uptake and ATP synthesis. Dual-luciferase reporter assay and RIP assay were conducted to analyze the relationship between miR-1236-3p and circ_0032821 or HMGB1. Western blot assay was adopted for high mobility group box 1 (HMGB1) level. Murine xenograft model assay was utilized for the effect of circ_0032821 in vivo.

Results

High level of circ_0032821 was observed in GC tissues and cells. Silencing of circ_0032821 markedly repressed cell proliferation, metastasis and glycolysis in GC cells in vitro and blocked tumorigenesis of GC in vivo. For mechanism analysis, circ_0032821 was identified as the sponge of miR-1236-3p and HMGB1 was the target gene of miR-1236-3p. Moreover, miR-1236-3p suppression restored the influences of circ_0032821 deficiency on GC cell proliferation, metastasis and glycolysis. Overexpression of miR-1236-3p relieved the malignant behaviors of GC cells by targeting HMGB1.

Conclusion

Circ_0032821 accelerated GC development through elevating HMGB1 expression via sponging miR-1236-3p.

CircRNA ITCH increases bortezomib sensitivity through regulating the miR-615-3p/PRKCD axis in multiple myeloma

AIMS

Bortezomib (BTZ) is described as the first-line agent for multiple myeloma (MM) chemotherapy, but the emergence of BTZ resistance usually results in the failure of chemotherapy in MM. Circular RNA (circRNA) itchy E3 ubiquitin protein ligase (circITCH) is a novel identified circRNA that plays a vital role in the development of human cancers. However, the role of circITCH in the development of BTZ resistance in MM remains elusive.

MATERIALS AND METHODS

The expression of circITCH, miR-615-3p, and protein kinase C, delta (PRKCD) was detected with quantitative reverse transcription PCR and western blot. The effects of circITCH on the sensitivity of MM cells to BTZ were assessed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, flow cytometry, and xenograft tumor assay. The interaction of circITCH, microRNA-615-3p, and PRKCD was explored using luciferase reporter assay and RNA immunoprecipitation assay.

KEY FINDINGS

circITCH was downregulated in MM bone marrow specimens and cell lines, as well as BTZ-resistant MM cells. Reduced expression of circITCH was indicative of poor prognosis in MM patients. Upregulation of circITCH enhanced the sensitivity of BTZ-resistant MM cells to BTZ in vitro and in vivo. Furthermore, circITCH was identified as a sponge for miR-615-3p, and PRKCD is confirmed as a direct target of miR-615-3p. Besides, circITCH overexpression enhanced the sensitivity of MM cells to BTZ through miR-615-3p/PRKCD axis.

SIGNIFICANCE

circITCH overexpression enhanced the sensitivity of MM cells to BTZ through miR-615-3p/PRKCD axis, providing a novel potential target for combating BTZ resistance in patients with MM.

MicroRNA-615 functions as a tumor suppressor in osteosarcoma through the suppression of HK2

At present, the regulatory mechanisms of various microRNAs (miRNAs/miRs) have been elucidated in human cancers including osteosarcoma (OS). This study mainly focused on the role of miR-615 in OS, which has not yet been reported. Ninety-two OS tissues and normal samples were used in this study. Human osteoblast hFOB1.19 cells and OS cell line HOS were utilized to detect the expression of miR-615. The expression of miR-615 and gene expression were assessed by RT-qPCR and western blot analysis. Transwell, MTT and luciferase reporter assays were used to investigate the regulatory mechanism of miR-615 in OS. The results revealed that miR-615 expression was reduced in OS tissues and cells, and was associated with poor clinical outcomes and prognosis in OS patients. In addition, overexpression of miR-615 restrained cell viability and metastasis in OS. Furthermore, hexokinase 2 (HK2) was confirmed as a direct target of miR-615. Upregulation of HK2 was detected in OS tissues. The upregulation of HK2 weakened the tumor-suppressive effect of miR-615 in OS. Moreover, miR-615 blocked epithelial-mesenchymal transition (EMT) and inactivated the PI3K/AKT pathway in OS. To conclude, miR-615 acts as a tumor suppressor in OS, thus miR-615 can be used as a target for OS treatment.

miRNAs expression signature potentially associated with lymphatic dissemination in locally advanced prostate cancer

Background

Prostate cancer is one of the most common and socially significant cancers among men. The aim of our study was to reveal changes in miRNA expression profiles associated with lymphatic dissemination in prostate cancer and to identify the most prominent miRNAs as potential prognostic markers for future studies.

Methods

High-throughput miRNA sequencing was performed for 44 prostate cancer specimens taken from Russian patients, with and without lymphatic dissemination (N1 – 20 samples; N0 – 24 samples).

Results

We found at least 18 microRNAs with differential expression between N0 and N1 sample groups: miR-182-5p, miR-183-5p, miR-96-5p, miR-25-3p, miR-93-5p, miR-7-5p, miR-615-3p, miR-10b, miR-1248 (N1-miRs; elevated expression in N1 cohort; p < 0.05); miR-1271-5p, miR-184, miR-222-3p, miR-221-5p, miR-221-3p, miR-455-3p, miR-143-5p, miR-181c-3p and miR-455-5p (N0-miRs; elevated expression in N0; p < 0.05). The expression levels of N1-miRs were highly correlated between each other (the same is applied for N0-miRs) and the expression levels of N0-miRs and N1-miRs were anti-correlated. The tumor samples can be divided into two groups depending on the expression ratio between N0-miRs and N1-miRs.

Conclusions

We found the miRNA expression signature associated with lymphatic dissemination, in particular on the Russian patient cohort. Many of these miRNAs are well-known players in either oncogenic transformation or tumor suppression. Further experimental studies with extended sampling are required to validate these results.

Comprehensive Analysis of Prognostic Alternative Splicing Signatures in Oral Squamous Cell Carcinoma

Background

Alternative splicing (AS) plays an essential role in tumorigenesis and progression. This study aimed to develop a novel prognostic model based on the AS events to obtain more accurate survival prediction and search for potential therapeutic targets in oral squamous cell carcinoma (OSCC).

Methods

Seven types of AS events in 326 OSCC patients with RNA-seq were obtained from the TCGA SpliceSeq tool and the TCGA database. Cox analysis, the least absolute shrinkage and selection operator Cox regression and random forest were employed to establish prognostic models. Genomics of Drug Sensitivity in Cancer (GDSC) was adopted to estimate the possible drug sensiticity. Prognostic splicing factor (SF)-AS network was constructed by Cytoscape.

Results

The final model included 12 AS events, showing satisfactory performance. The area under the curve for 3- and 5-year survival in the training cohort was 0.83 and 0.82, respectively while that in internal validation was 0.83 and 0.82 accordingly. The calibration curve also indicated a satisfactory agreement between the observation and the predictive values. Low-risk patients stratified by the final model presented higher sensitivity to three chemo drugs. Besides, the prognostic SF-AS regulatory network contained five key SFs and 62 AS events.

Conclusions

We developed a powerful prognostic AS signature for OSCC and deepened the understanding of SF-AS network regulatory mechanisms. Low-risk patients tended to be more sensitive to the three chemo drugs while five key SFs including CELF2, TIA1, HNRNPC, HNRNPK, and SRSF9 were identified as potential prognostic biomarkers, which may offer new prospects for effective therapies of OSCC.

miR-615 Fine-Tunes Growth and Development and Has a Role in Cancer and in Neural Repair

MicroRNAs (miRNAs) are small noncoding RNAs that function as epigenetic modulators regulating almost any gene expression. Similarly, other noncoding RNAs, as well as epigenetic modifications, can regulate miRNAs. This reciprocal interaction forms a miRNA-epigenetic feedback loop, the deregulation of which affects physiological processes and contributes to a great diversity of diseases. In the present review, we focus on miR-615, a miRNA highly conserved across eutherian mammals. It is involved not only during embryogenesis in the regulation of growth and development, for instance during osteogenesis and angiogenesis, but also in the regulation of cell growth and the proliferation and migration of cells, acting as a tumor suppressor or tumor promoter. It therefore serves as a biomarker for several types of cancer, and recently has also been found to be involved in reparative processes and neural repair. In addition, we present the pleiad of functions in which miR-615 is involved, as well as their multiple target genes and the multiple regulatory molecules involved in its own expression. We do this by introducing in a comprehensible way the reported knowledge of their actions and interactions and proposing an integral view of its regulatory mechanisms.

Exosomal Transfer of lncRNA H19 Promotes Erlotinib Resistance in Non-Small Cell Lung Cancer via miR-615-3p/ATG7 Axis

Background

Drug resistance restrains the effect of drug therapy in non-small cell lung cancer (NSCLC). However, the mechanism of the acquisition of drug resistance remains largely unknown. This study aims to investigate the effect of exosomal lncRNA H19 on erlotinib resistance in NSCLC and the underlying mechanism.

Methods

HCC827 and A549 cells were continuously grafted into erlotinib-containing culture medium to establish erlotinib-resistant cell lines. The expression of H19 and miR-615-3p was detected by qRT-PCR. The protein levels of MMP2, MMP9, CD9, CD63 and ATG7 were measured by Western blot. Cell viability and proliferation were determined by Cell Counting Kit-8 (CCK-8) and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, respectively. Migration and invasion were assessed by transwell assay. Xenograft tumor models were used to investigate the effect of H19 on erlotinib resistance in vivo. Online software and dual-luciferase reporter assay were used to predicate the downstream targets and confirm the targeted relationships.

Results

H19 was upregulated in erlotinib-resistant cells, and knockdown of H19 inhibited cell proliferation, migration and invasion in erlotinib-resistant cells. Extracellular H19 can be packaged into exosomes. Exosomes containing H19 induced erlotinib resistance of sensitive cells, while knockdown of H19 abolished this effect. miR-615-3p was a target of H19 and can bind to ATG7. Exosomal H19 affected erlotinib resistance of erlotinib-resistant NSCLC cells via targeting miR-615-3p to regulate ATG7 expression. In addition, the serum exosomal H19 was upregulated in patients with erlotinib resistance. Furthermore, downregulated H19 decreased the resistance of tumor cells to erlotinib in vivo.

Conclusion

Our study demonstrated that exosomal H19 facilitated erlotinib resistance in NSCLC via miR-615-3p/ATG7 axis, which might provide a potential target for the diagnosis and treatment of NSCLC.

MicroRNA-6744-5p promotes anoikis in breast cancer and directly targets NAT1 enzyme

Objective: Anoikis is apoptosis that is induced when cells detach from the extracellular matrix and neighboring cells. As anoikis serves as a regulatory barrier, cancer cells often acquire resistance towards anoikis during tumorigenesis to become metastatic. MicroRNAs (miRNAs) are short strand RNA molecules that regulate genes post-transcriptionally by binding to mRNAs and reducing the expression of its target genes. This study aimed to elucidate the role of a novel miRNA, miR-6744-5p, in regulating anoikis in breast cancer and identify its target gene. Methods: An anoikis resistant variant of the luminal A type breast cancer MCF-7 cell line (MCF-7-AR) was generated by selecting and amplifying surviving cells after repeated exposure to growth in suspension. MiRNA microarray analysis identified a list of dysregulated miRNAs from which miR-6744-5p was chosen for overexpression and knockdown studies in MCF-7. Additionally, the miRNA was also overexpressed in a triple-negative breast cancer cell line, MDA-MB-231, to evaluate its ability to impair the metastatic potential of breast cancer cells. Results: This study showed that overexpression and knockdown of miR-6744-5p in MCF-7 increased and decreased anoikis sensitivity, respectively. Similarly, overexpression of miR-6744-5p in MDA-MB-231 increased anoikis and also decreased tumor cell invasion in vitro and in vivo. Furthermore, NAT1 enzyme was identified and validated as the direct target of miR-6744-5p. Conclusions: This study has proven the ability of miR-6744-5p to increase anoikis sensitivity in both luminal A and triple negative breast cancer cell lines, highlighting its therapeutic potential in treating breast cancer.

Circular RNA-Centered Regulatory Networks in the Physiopathology of Cardiovascular Diseases

Non-coding regulatory RNAs are generated as a core output of the eukaryotic genomes, being essential players in cell biology. At the organism level, they are key functional actors in those tissues and organs with limited proliferation capabilities such as the heart. The role of regulatory networks mediated by non-coding RNAs in the pathophysiology of cardiovascular conditions is starting to be unveiled. However, a deeper knowledge of the functional interactions among the diverse non-coding RNA families and their phenotypic consequences is required. This review presents the current knowledge about the functional crosstalk between circRNAs and other biomolecules in the framework of the cardiovascular diseases.

Interactions Among Regulatory Non-coding RNAs Involved in Cardiovascular Diseases

Non-coding RNAs (ncRNAs) are important regulatory players in human cells that have been shown to modulate different cellular processes and biological functions through controlling gene expression, being also involved in pathological conditions such as cardiovascular diseases. Among them, long non-coding RNAs (lncRNAs) and circular (circRNAs) could act as competing endogenous RNAs (ceRNAs) sequestering other ncRNAs. This entangled network of interactions has been reported to trigger the decay of the targeted ncRNAs having important roles in gene regulation. Growing evidences have been demonstrated that the regulatory mechanism underlying the crosstalk between different ncRNA species, namely lncRNAs, circRNAs and miRNAs has also an important role in the pathophysiological processes of cardiovascular diseases. In this chapter, the main regulatory relationship among lncRNAs, circRNAs and miRNAs were summarized and their role in the control and development of cardiovascular diseases was highlighted.

Four transcription profile-based models identify novel prognostic signatures in oesophageal cancer

Oesophageal cancer (ESCA) is a clinically challenging disease with poor prognosis and health-related quality of life. Here, we investigated the transcriptome of ESCA to identify high risk-related signatures. A total of 159 ESCA patients of The Cancer Genome Atlas (TCGA) were sorted by three phases. In the discovery phase, differentially expressed transcripts were filtered; in the training phase, two adjusted Cox regressions and two machine leaning models were used to construct and estimate signatures; and in the validation phase, prognostic signatures were validated in the testing dataset and the independent external cohort. We constructed two signatures from three types of RNA markers by Akaike information criterion (AIC) and least absolute shrinkage and selection operator (LASSO) Cox regressions, respectively, and all candidate markers were further estimated by Random Forest (RFS) and Support Vector Machine (SVM) algorithms. Both signatures had good predictive performances in the independent external oesophageal squamous cell carcinoma (ESCC) cohort and performed better than common clinicopathological indicators in the TCGA dataset. Machine learning algorithms predicted prognosis with high specificities and measured the importance of markers to verify the risk weightings. Furthermore, the cell function and immunohistochemical (IHC) staining assays identified that the common risky marker FABP3 is a novel oncogene in ESCA.

A Novel Biomarker Based on miRNA to Predict the Prognosis of Muscle-Invasive Bladder Urothelial Carcinoma

Muscle-invasive bladder urothelial carcinoma (MIBC) is characteristic of high mortality and high recurrence. Distinguishing the prognostic risk of MIBC at the molecular level of miRNA expression is rarely performed and thus of great significance for the management and treatment of MIBC in clinics. Adaptive lasso Cox's proportional hazards model was used to explore the relationship between differential expression miRNAs (DEmiRNAs) and MIBC survival. Furthermore, we evaluated the epithelial-mesenchymal transition (EMT) score and immune infiltration abundance by exploring EMT signature genes and TIMER database, respectively. A total of 8 DEmiRNAs were detected to be associated with the survival rate of MIBC by using the lasso Cox algorithm. Through the linear combination of these 8 DEmiRNAs, we constructed a calculated marker, which could be used to distinguish the prognosis risk in both TCGA dataset (HR = 2.03, 95% CI = (1.47, 2.83)) and independent validation dataset (HR = 7.74, 95% CI = (1.05, 56.93)). Meanwhile, the constructed marker had reasonably high predictive values of the AUC (area under the curve) in the TCGA dataset and validation dataset being 0.73 and 0.63, respectively. In addition, we observed that the expression values of let-7c, miR-100, and miR-145 were associated with EMT score and the abundance of macrophage in tumor tissue as well. This newly identified risk score signature based on the combination of 8 miRNAs could significantly predict the prognostic risk of MIBC and might provide insight into immunotherapy and targeted therapy of MIBC.

Clinical Significance of microRNA-196b-5p in Hepatocellular Carcinoma and its Potential Molecular Mechanism

Objective: To enquire into the clinical significance and potential molecular mechanism of microRNA (miRNA)-196b-5p in hepatocellular carcinoma (HCC).

Methods: Quantitative reverse transcription and polymerase chain reaction (qRT-PCR) were utilized to examine miR-196b-5p expression level in 67 HCC paraffin embedded tissues and corresponding adjacent tissues. Correlations of miR-196b-5p expression level with clinicopathological characteristics were analyzed in our study. The expression level and clinical significance of miR-196b-5p in HCC were also evaluated in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. We made predictions of the target genes of miR-196b-5p by twelve online software and then selected genes predicted by at least 5 software. Subsequently, in order to obtain the potential target genes of miR-196b-5p, we overlapped the predicted target genes and down-regulated mRNAs in HCC based on TCGA database. Then, we performed the Gene Ontology (GO) and the Disease Ontology (DO) functional annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and Protein-Protein Interaction (PPI) network construction of those miR-196b-5p potential target genes.

Results: Higher expression level of miR-196b-5p was seen in HCC tissues than in the corresponding adjacent tissues based on qRT-PCR (P = 0.0007). The expression level of miR-196b-5p was linked with tumor size (P = 0.03), tumor node (P = 0.024), vascular invasion (P = 0.029) and capsular invasion (P = 0.026) in HCC patients. Comprehensive meta-analysis of miR-196b-5p expression based on TCGA, GEO and qRT-PCR verified that higher expression level of miR-196b-5p was observed in HCC tissues than in normal control liver tissues (SMD = 0.56, 95%CI: 0.39-0.72, P_{heterogeneity} = 0.275, I² = 18.3%). GO annotation revealed that the top terms in biological process, cellular component and molecular function were single-organism catabolic process, neuronal cell body and transmembrane receptor protein kinase activity, respectively. The most relevant disease in DO annotation was arteriosclerosis. The tryptophan metabolism pathway ranked first in KEGG pathway enrichment analysis. The PPI network showed that IGF1, FOXO1, AR and FOS were mostly likely to become the core genes of miR-196b-5p potential target genes, which however required further experiments for validation.

Conclusion: The miR-196b-5p was observed to show higher expression in HCC tissues than in normal control liver tissues. Moreover, the miR-196b-5p expression level had correlations with the clinicopathological parameters such as vascular invasion of HCC, but the molecular mechanisms of miR-196b-5p in HCC still need further elucidation and verification.

miRNome Reveals New Insights Into the Molecular Biology of Field Cancerization in Gastric Cancer

BACKGROUND

MicroRNAs (miRNAs) play an important role in gastric carcinogenesis and have been associated with gastric field cancerization; however, their role is not fully understood in this process. We performed the miRNome sequencing of non-cancerous, adjacent to tumor and gastric cancer samples to understand the involvement of these small RNAs in gastric field cancerization.

METHODS

We analyzed samples of patients without cancer as control (non-cancerous gastric samples) and adjacent to cancer and gastric cancer paired samples, and considered miRNAs with |log2(fold change)| > 2 and Padj < 0.05 to be statistically significant. The identification of target genes, functional analysis and enrichment in KEGG pathways were realized in the TargetCompare, miRTargetLink, and DAVID tools. We also performed receiver operating characteristic (ROC) curves and miRNAs that had an AUC > 0.85 were considered to be potential biomarkers.

RESULTS

We found 14 miRNAs exclusively deregulated in gastric cancer, of which six have potential diagnostic value for advanced disease. Nine miRNAs with known tumor suppressor activities (TS-miRs) were deregulated exclusively in adjacent tissue. Of these, five have potential diagnostic value for the early stages of gastric cancer. Functional analysis of these TS-miRs revealed that they regulate important cellular signaling pathways (PI3K-Akt, HIF-1, Ras, Rap1, ErbB, and MAPK signaling pathways), that are involved in gastric carcinogenesis. Seven miRNAs were differentially expressed in both gastric cancer and adjacent regarding to non-cancerous tissues; among them, hsa-miR-200a-3p and hsa-miR-873-5p have potential diagnostic value for early and advanced stages of the disease. Only hsa-miR-196a-5p was differentially expressed between adjacent to cancer and gastric cancer tissues. In addition, the other miRNAs identified in this study were not differentially expressed between adjacent to cancer and gastric cancer, suggesting that these tissues are very similar and that share these molecular changes.

CONCLUSION

Our results show that gastric cancer and adjacent tissues have a similar miRNA expression profile, indicating that studied miRNAs are intimately associated with field cancerization in gastric cancer. The overexpression of TS-miRs in adjacent tissues may be a barrier against tumorigenesis within these pre-cancerous conditions prior to the eventual formation or relapse of a tumor. Additionally, these miRNAs have a great accuracy in discriminating non-cancerous from adjacent to tumor and cancer tissues and can be potentially useful as biomarkers for gastric cancer.