IGF2BP2 promotes colorectal cancer cell proliferation and survival through interfering with RAF-1 degradation by miR-195

IMPlications of IMP2 in RNA Biology and Disease

Insulin-like growth factor 2 mRNA-binding protein 2 (IMP2) is an RNA-binding protein that positively regulates m6A-modified RNAs involved in critical cellular processes such as metabolism, oncogenesis, and immune function. Here, we elucidate facets of IMP2 biology, including several mechanisms of action on RNA, factors that regulate IMP2 expression, its relevant biological target RNAs, its role in normal development and disease, and its potential as a therapeutic target. IMP2 is a multi-level regulator of metabolism, influencing pathways linked to diabetes, obesity, and adipose function. Through genomic amplification and transcriptional overexpression in cancer cells, IMP2 can drive the initiation and progression of multiple cancer types, and high expression is associated with decreased overall survival of patients with cancer. IMP2 influences normal immune function, inflammation, macrophage polarization, and tumor immune evasion. IMP2 has emerged as a promising therapeutic target, particularly for cancers and metabolic diseases.

Multifaceted roles of insulin‑like growth factor 2 mRNA binding protein 2 in human cancer (Review)

Insulin‑like growth factor 2 mRNA binding protein 2 (IGF2BP2) is an RNA binding protein that functions as an N6‑methyladenosine reader. It regulates various biological processes in human cancers by affecting the stability and expression of target RNA transcripts, including coding RNAs and non‑coding RNAs (ncRNAs). Numerous studies have shown that IGF2BP2 expression is aberrantly increased in various types of cancer and plays multifaceted roles in the development and progression of human cancers. In the present review, the clinical importance of IGF2BP2 is summarized and its involvement in the regulation of biological processes, including proliferation, metastasis, chemoresistance, metabolism, tumor immunity, stemness and cell death, in human cancers is discussed. The chemical compounds that have been developed as IGF2BP2 inhibitors are also detailed. As ncRNAs are now important potential therapeutic agents for cancer treatment, the microRNAs that have been reported to directly target and inhibit IGF2BP2 expression in cancers are also described. In summary, by reviewing the latest literature, the present study aimed to highlight the clinical importance and physiological functions of IGF2BP2 in human cancer, with a focus on the great potential of IGF2BP2 as a target for inhibitor development. The present review may inspire new ideas for future studies on IGF2BP2, which may serve as a specific therapeutic target in cancer.

Chicoric acid exerts therapeutic effects in DSS-induced ulcerative colitis by targeting the USP9X/IGF2BP2 axis

BACKGROUND AND PURPOSE

Chicoric acid, a hydroxycinnamic acid, exhibits anti-inflammation activities. However, the specific mechanisms underlying the effects of chicoric acid on dextran sulfate sodium (DSS)-induced colitis remain unclear. Here, we aimed to elucidate the molecular mechanisms underlying the protective effects of chicoric acid in DSS-induced colitis.

EXPERIMENTAL APPROACH

Mice with DSS-induced colitis (UC mice) were treated for a week with chicoric acid. Symptoms of colitis, colonic pathology, inflammation-related indicators, and intestinal mucosal barrier function were evaluated. RNA sequencing was performed on colon tissues to obtain differentially expressed genes. The deubiquitinating enzyme USP9X was selected, and the inhibitory and targeting effects of chicoric acid on USP9X were subsequently determined. In vivo and in vitro, DSS-induced colitis was treated with USP9X inhibitors WP1130 and EOAI3402143. Ubiquitination label-free quantitative proteomic analysis was performed to identify protein peptides that may undergo de-ubiquitination by USP9X. Co-immunoprecipitation (Co-IP), immunohistochemistry and western blotting were used to validate in vivo and in vitro results.

KEY RESULTS

Chicoric acid significantly alleviated clinical activity and histological changes, inhibited pro-inflammatory cytokine production and improved integrity of the intestinal barrier in UC mice. Moreover, chicoric acid suppressed USP9X expression in colonic tissues from UC mice. Furthermore, USP9X contributed to promoting the onset of UC and that insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) was deubiquitinated by USP9X.

CONCLUSION AND IMPLICATIONS

Chicoric acid ameliorated DSS-induced colitis by targeting the USP9X/IGF2BP2 axis, indicating that targeting the USP9X/IGF2BP2 axis presents a promising and innovative therapeutic approach for the treatment of UC.

Bioinformatic identification reveals a m6A-binding protein, IGF2BP2, as a novel tumor-promoting gene signature in thyroid carcinoma

N6-methyladenosine (m6A) modification plays a crucial role in thyroid carcinoma (THCA). Insulin-like growth factor 2 binding protein 2 (IGF2BP2) is a m6A-binding protein. We aimed to explore the effect of IGF2BP2 on the development of THCA. Differentially expressed genes (DEGs) were screened from GSE50901 and GSE60542 datasets. LinkedOmics, Genebank, and Sequence-based RNA Adenosine Methylation Site Predictor databases were employed to find potential m6A modification sites. Protein-protein interaction network and receiver-operating characteristic curves were applied to determine hub genes of THCA. ESTIMATE revealed the effect of IGF2BP2 on tumor immunity. The mRNA expression of IGF2BP2 was detected using real-time quantitative polymerase chain reaction. The viability, migration, and invasion were assessed by Cell Counting Kit-8, wound healing, and transwell assays. A total of 166 common DEGs were identified from GSE50901 and GSE60542 datasets. One m6A-related gene, IGF2BP2, was differentially expressed in THCA and selected as the research target. The hub genes (CD44, DCN, CXCL12, ICAM1, SDC4, KIT, CTGF, and FMOD) were identified with high prediction values for THCA. Subsequently, the target genes of IGF2BP2, SDC4, and ICAM1, which had potential m6A modification sites, were screened out based on the hub genes. IGF2BP2 was upregulated in THCA and IGF2BP2 expression was positively correlated with immune infiltration in THCA. Additionally, knockdown of IGF2BP2 inhibited the proliferation, invasion, and migration of THCA cells. IGF2BP2 has a contributory effect on the progression of THCA, which is a novel biomarker and a therapeutic target for THCA.

circHIPK3 nucleates IGF2BP2 and functions as a competing endogenous RNA

Circular RNAs represent a class of endogenous RNAs that regulate gene expression and influence cell biological decisions with implications for the pathogenesis of several diseases. Here, we disclose a novel gene-regulatory role of circHIPK3 by combining analyses of large genomics datasets and mechanistic cell biological follow-up experiments. Using time-course depletion of circHIPK3 and specific candidate RNA-binding proteins, we identify several perturbed genes by RNA sequencing analyses. Expression-coupled motif analyses identify an 11-mer motif within circHIPK3, which also becomes enriched in genes that are downregulated upon circHIPK3 depletion. By mining eCLIP datasets and combined with RNA immunoprecipitation assays, we demonstrate that the 11-mer motif constitutes a strong binding site for IGF2BP2 in bladder cancer cell lines. Our results suggest that circHIPK3 can sequester IGF2BP2 as a competing endogenous RNA (ceRNA), leading to target mRNA stabilization. As an example of a circHIPK3-regulated gene, we focus on the STAT3 mRNA as a specific substrate of IGF2BP2 and validate that manipulation of circHIPK3 regulates IGF2BP2-STAT3 mRNA binding and, thereby, STAT3 mRNA levels. Surprisingly, absolute copy number quantifications demonstrate that IGF2BP2 outnumbers circHIPK3 by orders of magnitude, which is inconsistent with a simple 1:1 ceRNA hypothesis. Instead, we show that circHIPK3 can nucleate multiple copies of IGF2BP2, potentially via phase separation, to produce IGF2BP2 condensates. Our results support a model where a few cellular circHIPK3 molecules can induce IGF2BP2 condensation, thereby regulating key factors for cell proliferation.

circHIPK3 nucleates IGF2BP2 and functions as a competing endogenous RNA

Circular RNAs (circRNAs) represent a class of widespread endogenous RNAs that regulate gene expression and thereby influence cell biological decisions with implications for the pathogenesis of several diseases. Here, we disclose a novel gene-regulatory role of circHIPK3 by combining analyses of large genomics datasets and mechanistic cell biological follow-up experiments. Specifically, we use temporal depletion of circHIPK3 or specific RNA binding proteins (RBPs) and identify several perturbed genes by RNA sequencing analyses. Using expression-coupled motif analyses of mRNA expression data from various knockdown experiments, we identify an 11-mer motif within circHIPK3, which is also enriched in genes that become downregulated upon circHIPK3 depletion. By mining eCLIP datasets, we find that the 11-mer motif constitutes a strong binding site for IGF2BP2 and validate this circHIPK3-IGF2BP2 interaction experimentally using RNA-immunoprecipitation and competition assays in bladder cancer cell lines. Our results suggest that circHIPK3 and IGF2BP2 mRNA targets compete for binding. Since the identified 11-mer motif found in circHIPK3 is enriched in upregulated genes following IGF2BP2 knockdown, and since IGF2BP2 depletion conversely globally antagonizes the effect of circHIPK3 knockdown on target genes, our results suggest that circHIPK3 can sequester IGF2BP2 as a competing endogenous RNA (ceRNA), leading to target mRNA stabilization. As an example of a circHIPK3-regulated gene, we focus on the STAT3 mRNA as a specific substrate of IGF2BP2 and validate that manipulation of circHIPK3 regulates IGF2BP2- STAT3 mRNA binding and thereby STAT3 mRNA levels. However, absolute copy number quantifications demonstrate that IGF2BP2 outnumbers circHIPK3 by orders of magnitude, which is inconsistent with a simple 1:1 ceRNA hypothesis. Instead, we show that circHIPK3 can nucleate multiple copies of IGF2BP2, potentially via phase separation, to produce IGF2BP2 condensates. Finally, we show that circHIPK3 expression correlates with overall survival of patients with bladder cancer. Our results are consistent with a model where relatively few cellular circHIPK3 molecules function as inducers of IGF2BP2 condensation thereby regulating STAT3 and other key factors for cell proliferation and potentially cancer progression.

Targeting insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) for the treatment of cancer

Insulin-like growth factor 2 mRNA-binding proteins (IMPs, IGF2BPs) are RNA-binding proteins that regulate a variety of biological processes. In recent years, several studies have found that IGF2BPs play multiple roles in various biological processes, especially in cancer, and speculated on their mechanism of anticancer effect. In addition, targeting IGF2BPs or their downstream target gene has also received extensive attention as an effective treatment for different types of cancer. In this review, we summarized the recent progress on the role of IGF2BPs in cancers and their structural characteristics. We focused on describing the development of inhibitors targeting IGF2BPs and the prospects for further applications.

IGF2BPs as novel m6A readers: Diverse roles in regulating cancer cell biological functions, hypoxia adaptation, metabolism, and immunosuppressive tumor microenvironment

m6A methylation is the most frequent modification of mRNA in eukaryotes and plays a crucial role in cancer progression by regulating biological functions. Insulin-like growth factor 2 mRNA-binding proteins (IGF2BP) are newly identified m6A 'readers'. They belong to a family of RNA-binding proteins, which bind to the m6A sites on different RNA sequences and stabilize them to promote cancer progression. In this review, we summarize the mechanisms by which different upstream factors regulate IGF2BP in cancer. The current literature analyzed here reveals that the IGF2BP family proteins promote cancer cell proliferation, survival, and chemoresistance, inhibit apoptosis, and are also associated with cancer glycolysis, angiogenesis, and the immune response in the tumor microenvironment. Therefore, with the discovery of their role as 'readers' of m6A and the characteristic re-expression of IGF2BPs in cancers, it is important to elucidate their mechanism of action in the immunosuppressive tumor microenvironment. We also describe in detail the regulatory and interaction network of the IGF2BP family in downstream target RNAs and discuss their potential clinical applications as diagnostic and prognostic markers, as well as recent advances in IGF2BP biology and associated therapeutic value.

Discovering potential inhibitors of Raf proto-oncogene serine/threonine kinase 1: a virtual screening approach towards anticancer drug development

Raf proto-oncogene serine/threonine kinase 1 (RAF1 or c-Raf) is a serine/threonine protein kinase crucial in regulating cell growth, differentiation, and survival. Any disruption or overexpression of RAF1 can result in neoplastic transformation and other disorders such as cardiomyopathy, Noonan syndrome, leopard syndrome, etc. RAF1 has been identified as a potential therapeutic target in drug development against various complex diseases, including cancer, due to its remarkable role in disease progression. Here, we carried out a multitier virtual screening study involving different in-silico approaches to discover potential inhibitors of RAF1. After applying the Lipinski rule of five, we retrieved all phytocompounds from the IMPPAT database based on their physicochemical properties. We performed a molecular docking-based virtual screening and got top hits with the best binding affinity and ligand efficiency. Then we screened out the selected hits using the PAINS filter, ADMET properties, and other druglike features. Eventually, PASS evaluation identifies two phytocompounds, Moracin C and Tectochrysin, with appreciable anti-cancerous properties. Finally, all-atom molecular dynamics simulation (MDS) followed by interaction analysis was performed on the elucidated compounds in complex with RAF1 for 200 ns to investigate their time-evolution dynamics and interaction mechanism. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) and Dynamical Cross-Correlation Matrix (DCCM) analyses then followed these results from the simulated trajectories. According to the results, the elucidated compounds stabilize the RAF1 structure and lead to fewer conformational alterations. The results of the current study indicated that Moracin C and Tectochrysin could serve as potential inhibitors of RAF1 after required validation.Communicated by Ramaswamy H. Sarma.

A Transcription Factor ZNF384, Regulated by LINC00265, Activates the Expression of IFI30 to Stimulate Malignant Progression in Glioma

Glioma remains one of the most challenging primary brain malignancies to treat. Long noncoding RNAs (lncRNAs) and mRNAs (mRNAs) are implicated in regulating the malignant phenotypes of cancers including glioma. This study aimed to elucidate the functions and mechanisms of lncRNA LINC00265 and mRNA IFI30 in the pathogenesis of glioma. Quantitative real-time polymerase chain reaction (RT-qPCR) analysis revealed the upregulated expression of LINC00265 and IFI30 in glioma cells compared to normal human astrocytes. Western blot (WB) quantified the associated proteins. Glioma stemness and epithelial-to-mesenchymal transition (EMT) were assessed by aldehyde dehydrogenase 1 (ALDH1) activity, sphere formation, and WB. Mechanistic and rescue assays evaluated the LINC00265/miR-let-7d-5p/IFI30/ZNF384/IGF2BP2 axis. The results demonstrated that LINC00265 and IFI30 were highly expressed in glioma cells, promoting stemness and EMT. ZNF384 was identified as a transcription factor that upregulates IFI30. Moreover, LINC00265 elevated ZNF384 by sponging miR-let-7d-5p and recruiting IGF2BP2. In conclusion, LINC00265 and IFI30 act as oncogenes in glioma by driving stemness and EMT, underscoring their potential as therapeutic targets.

The emerging role of m6A modification of non-coding RNA in gastrointestinal cancers: a comprehensive review

Gastrointestinal (GI) cancer is a series of malignant tumors with a high incidence globally. Although approaches for tumor diagnosis and therapy have advanced substantially, the mechanisms underlying the occurrence and progression of GI cancer are still unclear. Increasing evidence supports an important role for N6-methyladenosine (m6A) modification in many biological processes, including cancer-related processes via splicing, export, degradation, and translation of mRNAs. Under distinct cancer contexts, m6A regulators have different expression patterns and can regulate or be regulated by mRNAs and non-coding RNAs, especially long non-coding RNAs. The roles of m6A in cancer development have attracted increasing attention in epigenetics research. In this review, we synthesize progress in our understanding of m6A and its roles in GI cancer, especially esophageal, gastric, and colorectal cancers. Furthermore, we clarify the mechanism by which m6A contributes to GI cancer, providing a basis for the development of diagnostic, prognostic, and therapeutic targets.

IGF2BP2 promotes head and neck squamous carcinoma cell proliferation and growth via the miR-98-5p/PI3K/Akt signaling pathway

Introduction

As a N6-methyladenosine reader protein, Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) is a critical player in tumor progression and metastasis. However, its specific function in head and neck squamous carcinoma (HNSCC) has yet to be determined. The present study aimed to determine the role of IGF2BP2 in HNSCC.

Methods

The expression of IGF2BP2 in HNSCC was analyzed using The Cancer Genome Atlas (TCGA) dataset and detected in HNSCC tissues and cells, respectively. Gain- and loss- of function methods were employed to study the effects of IGF2BP2 on HNSCC cell proliferation and tumorigenesis in vitro and in vivo. MicroRNAs (miRNAs) regulating IGF2BP2 were predicted using online tools and confirmed experimentally.

Results

We showed augmented IGF2BP2 expression in HNSCC, which correlated with poor clinical outcomes. Functional studies showed that IGF2BP2 promoted HNSCC cell proliferation by facilitating cell cycle progression while inhibiting apoptosis. We further demonstrated that IGF2BP2 could enhance HNSCC cell tumorigenesis in vivo. Mechanistically, our data revealed that miR-98-5p could directly target IGF2BP2. The interplay between IGF2BP2 and miR-98-5p is essential to drive the progression of HNSCC via the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-protein kinase B (Akt) pathway signaling pathway.

Discussion

The current study revealed the oncogenic role of IGF2BP2 and provided insights into its potential mechanism in HNSCC tumorigenesis. Additionally, IGF2BP2 might represent a promising therapeutic target and serve as prognostic biomarker in patients with HNSCC.

METTL3/IGF2BP2 axis affects the progression of colorectal cancer by regulating m6A modification of STAG3

Colorectal cancer (CRC) is among the commonest malignant tumors of humans. Existing evidence has linked the poor prognosis of CRC with high expression of stromal antigen 3 (STAG3), but, the exact biological effect of STAG3 in CRC is still unclear. The aim of this research is to reveal the biological function and molecular mechanism of STAG3 in CRC. To investigate the differential expression of STAG3 in CRC tissues and cell lines compared to normal colon tissues and cell lines, Western blot (WB) and quantitative real-time PCR (qRT-PCR) techniques were utilized. STAG3 N6-methyladenosine (m6A) modification level were identified using m6A RNA immunoprecipitation (MeRIP). Additionally, the functional roles of methyltransferase-like protein 3 (METTL3) and insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) in CRC were explored by manipulating their levels via knockdown or overexpression. Cell proliferation was evaluated through Cell Counting Kit 8 (CCK-8) and clone formation experiments, while cell migration was assessed through wound healing experiments. Furthermore, cell apoptosis was detected using flow cytometry, and the protein expressions associated with proliferation and apoptosis were detected using WB. To identify the specific binding of target genes, RIP and pull-down assays were employed. Finally, the biological function of STAG3 in vivo was investigated through a xenotransplantation mouse tumor model. In CRC tissues and cell lines, STAG3 was up-regulated and accompanied by m6A methylation. Additionally, the expression of METTL3 was found to be upregulated in CRC tissues. Knocking down METTL3 resulted in a decrease in both the m6A level and protein expression of STAG3, inhibited cell proliferation and migration while promoting apoptosis, which were restored through STAG3 overexpression. Furthermore, online prediction indicated the interaction between STAG3 mRNA and IGF2BP2 protein, which was further verified by RIP experiments. IGF2BP2 downregulation led to decreased STAG3 protein expression, cell proliferation, and migration, but increased apoptosis. However, these impacts were reversed by STAG3 overexpression. Finally, subcutaneous tumor experiments conducted in nude mice also confirmed that METTL3 regulated CRC progression through STAG3 in vivo. The METTL3/IGF2BP2/STAG3 axis affects CRC progression in an m6A modification-dependent manner. This may guide targeted therapy in CRC patients.

Association Between Polymorphism in Diabetes Susceptibility Gene Insulin-Like Growth Factor 2mRNA-Binding Protein 2 and Risk of Diffuse Large B-Cell Lymphoma

Background

Numerous studies have shown that polymorphisms in the diabetes susceptibility gene, insulin-like growth factor 2mRNA-binding protein 2 (IGF2BP2), are associated with the occurrence and development of various malignant tumors; however, their correlation with the onset of diffuse large B-cell lymphoma (DLBCL) is still unknown. Therefore, this study aimed to explore whether IGF2BP2 polymorphisms increase the risk of developing DLBCL.

Methods

This study included 295 DLBCL patients and 331 healthy individuals. Peripheral blood was collected, and polymerase chain reaction-ligase detection reaction (PCR-LDR) was used to detect IGF2BP2 gene polymorphisms. Logistic regression was used to assess the association between IGF2BP2 polymorphism and the risk of DLBCL, adjusted for age, sex, and body mass index (BMI). P < .05 indicated statistical significance.

Results

The rs4402960 polymorphism in the IGF2BP2 gene was associated with the occurrence and development of DLBCL. After adjusting for age, sex, and BMI, GT (odd ratio [OR] = 1.54; 95% confidence interval [CI] = 1.08-2.19; P = .016), TT (OR = 2.00; 95% CI = 1.09-3.68; P = .026), and T genotype carrying (GT + TT) (OR = 1.62; 95% CI = 1.17-2.25; P = .004) significantly increased the risk of DLBCL. This study also found that the polymorphism rs1470579 was related to the development of DLBCL. After adjusting for age, sex, and BMI, AC (OR = 1.55; 95% CI = 1.11-2.17; P = .010), CC (OR = 2.18; 95% CI = 1.17-4.06; P = .014), and C genotype carrying (AC + CC) (OR = 1.64; 95% CI = 1.19-2.26; P = .002) significantly increased the risk of DLBCL.

Conclusions

Our study found that polymorphism in the IGF2BP2 gene was associated with an increased risk of developing DLBCL.

Comprehensive analysis of the expression of the IGF2BPs gene family in head and neck squamous cell carcinoma: Association with prognostic value and tumor immunity

Background

Head and neck squamous cell carcinoma (HNSCC) represents a predominant type of cancer found in the head and neck region, characterized by a high incidence and unfavorable prognosis. The IGF2BPs gene family, which belongs to the RNA-binding protein class, has been critically implicated in several cancers, and its involvement in HNSCC necessitates further exploration.

Objective

To explore the clinical significance and potential biological functions of the IGF2BPs gene family in HNSCC.

Methods

A bioinformatic methodology was employed to examine the expression profile, diagnostic and prognostic significance, and biological mechanisms of the IGF2BPs gene family in HNSCC, with a particular emphasis on its involvement in the immune function of HNSCC. This was followed by in vitro investigations to unravel the biological roles of the IGF2BPs gene family in HNSCC.

Results

This investigation has demonstrated that, in contrast with normal control tissue, HNSCC has a substantial elevation in the expression level of the IGF2BPs gene family. Patients with a high level of IGF2BPs gene family expression demonstrated higher prediction accuracy for HNSCC. Furthermore, patients with HNSCC and elevated IGF2BPs gene family expression levels exhibited poor survival outcomes. The IGF2BPs gene family displayed a significant association with a variety of immune infiltrating cells and immune genes in HNSCC. Studies conducted in vitro have confirmed that IGF2BP2 silencing suppressed the migration, proliferation, and invasion of HNSCC cells.

Conclusions

It has been determined that the IGF2BPs gene family plays a crucial part in the onset and progression of HNSCC, and its association with tumor immunity has been established. The IGF2BPs gene family holds promising potential as a diagnostic and prognostic biomarker for HNSCC.

Novel insights on perils and promises of miRNA in understanding colon cancer metastasis and progression

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.

Surmounting Cancer Drug Resistance: New Perspective on RNA-Binding Proteins

RNA-binding proteins (RBPs), being pivotal elements in both physiological and pathological processes, possess the ability to directly impact RNA, thereby exerting a profound influence on cellular life. Furthermore, the dysregulation of RBPs not only induces alterations in the expression levels of genes associated with cancer but also impairs the occurrence of post-transcriptional regulatory mechanisms. Consequently, these circumstances can give rise to aberrations in cellular processes, ultimately resulting in alterations within the proteome. An aberrant proteome can disrupt the equilibrium between oncogenes and tumor suppressor genes, promoting cancer progression. Given their significant role in modulating gene expression and post-transcriptional regulation, directing therapeutic interventions towards RBPs represents a viable strategy for combating drug resistance in cancer treatment. RBPs possess significant potential as diagnostic and prognostic markers for diverse cancer types. Gaining comprehensive insights into the structure and functionality of RBPs, along with delving deeper into the molecular mechanisms underlying RBPs in tumor drug resistance, can enhance cancer treatment strategies and augment the prognostic outcomes for individuals afflicted with cancer.

The oncogenic function of PLAGL2 is mediated via ASCL2 and IGF2 and a Wnt-independent mechanism in colorectal cancer

Colorectal cancer (CRC) tumorigenesis and progression are linked to common oncogenic mutations, especially in the tumor suppressor APC, whose loss triggers the deregulation of TCF4/β-Catenin activity. CRC tumorigenesis is also driven by multiple epimutational modifiers such as transcriptional regulators. We describe the common (and near-universal) activation of the zinc finger transcription factor and Let-7 target PLAGL2 in CRC and find that it is a key driver of intestinal epithelial transformation. PLAGL2 drives proliferation, cell cycle progression, and anchorage-independent growth in CRC cell lines and nontransformed intestinal cells. Investigating effects of PLAGL2 on downstream pathways revealed very modest effects on canonical Wnt signaling. Alternatively, we find pronounced effects on the direct PLAGL2 target genes IGF2, a fetal growth factor, and ASCL2, an intestinal stem cell-specific bHLH transcription factor. Inactivation of PLAGL2 in CRC cell lines has pronounced effects on ASCL2 reporter activity. Furthermore, ASCL2 expression can partially rescue deficits of proliferation and cell cycle progression caused by depletion of PLAGL2 in CRC cell lines. Thus, the oncogenic effects of PLAGL2 appear to be mediated via core stem cell and onco-fetal pathways, with minimal effects on downstream Wnt signaling.NEW & NOTEWORTHY A Let-7 target called PLAGL2 drives oncogenic transformation via Wnt-independent pathways. This work illustrates the robust effects of this zinc finger transcription factor in colorectal cancer (CRC) cell lines and nontransformed intestinal epithelium, with effects mediated, in part, via the direct target genes ASCL2 and IGF2. This has implications for the role of PLAGL2 in activation of onco-fetal and onco-stem cell pathways, contributing to immature and highly proliferative phenotypes in CRC.

An epigenetic modulator with promising therapeutic impacts against gastrointestinal cancers: A mechanistic review on microRNA-195

Due to their high prevalence, gastrointestinal cancers are one of the key causes of cancer-related death globally. The development of drug-resistant cancer cell populations is a major factor in the high mortality rate, and it affects about half of all cancer patients. Because of advances in our understanding of cancer molecular biology, non-coding RNAs (ncRNAs) have emerged as critical factors in the initiation and development of gastrointestinal cancers. Gene expression can be controlled in several ways by ncRNAs, including through epigenetic changes, interactions between microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) and proteins, and the function of lncRNAs as miRNA precursors or pseudogenes. As lncRNAs may be detected in the blood, circulating ncRNAs have emerged as a promising new class of non-invasive cancer biomarkers for use in the detection, staging, and prognosis of gastrointestinal cancers, as well as in the prediction of therapy efficacy. In this review, we assessed the role lncRNAs play in the progression, and maintenance of colorectal cancer, and how they might be used as therapeutic targets in the future.

Crosstalk between m6A and coding/non-coding RNA in cancer and detection methods of m6A modification residues

N6-methyladenosine (m6A) is one of the most common and well-known internal RNA modifications that occur on mRNAs or ncRNAs. It affects various aspects of RNA metabolism, including splicing, stability, translocation, and translation. An abundance of evidence demonstrates that m6A plays a crucial role in various pathological and biological processes, especially in tumorigenesis and tumor progression. In this article, we introduce the potential functions of m6A regulators, including "writers" that install m6A marks, "erasers" that demethylate m6A, and "readers" that determine the fate of m6A-modified targets. We have conducted a review on the molecular functions of m6A, focusing on both coding and noncoding RNAs. Additionally, we have compiled an overview of the effects noncoding RNAs have on m6A regulators and explored the dual roles of m6A in the development and advancement of cancer. Our review also includes a detailed summary of the most advanced databases for m6A, state-of-the-art experimental and sequencing detection methods, and machine learning-based computational predictors for identifying m6A sites.

A combined computational and functional approach identifies IGF2BP2 as a driver of chemoresistance in a wide array of pre-clinical models of colorectal cancer

AIM

Chemoresistance is a major cause of treatment failure in colorectal cancer (CRC) therapy. In this study, the impact of the IGF2BP family of RNA-binding proteins on CRC chemoresistance was investigated using in silico, in vitro, and in vivo approaches.

METHODS

Gene expression data from a well-characterized cohort and publicly available cross-linking immunoprecipitation sequencing (CLIP-Seq) data were collected. Resistance to chemotherapeutics was assessed in patient-derived xenografts (PDXs) and patient-derived organoids (PDOs). Functional studies were performed in 2D and 3D cell culture models, including proliferation, spheroid growth, and mitochondrial respiration analyses.

RESULTS

We identified IGF2BP2 as the most abundant IGF2BP in primary and metastastatic CRC, correlating with tumor stage in patient samples and tumor growth in PDXs. IGF2BP2 expression in primary tumor tissue was significantly associated with resistance to selumetinib, gefitinib, and regorafenib in PDOs and to 5-fluorouracil and oxaliplatin in PDX in vivo. IGF2BP2 knockout (KO) HCT116 cells were more susceptible to regorafenib in 2D and to oxaliplatin, selumitinib, and nintedanib in 3D cell culture. Further, a bioinformatic analysis using CLIP data suggested stabilization of target transcripts in primary and metastatic tumors. Measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) revealed a decreased basal OCR and an increase in glycolytic ATP production rate in IGF2BP2 KO. In addition, real-time reverse transcriptase polymerase chain reaction (qPCR) analysis confirmed decreased expression of genes of the respiratory chain complex I, complex IV, and the outer mitochondrial membrane in IGF2BP2 KO cells.

CONCLUSIONS

IGF2BP2 correlates with CRC tumor growth in vivo and promotes chemoresistance by altering mitochondrial respiratory chain metabolism. As a druggable target, IGF2BP2 could be used in future CRC therapy to overcome CRC chemoresistance.

Effect of circular RNAs and N6-methyladenosine (m6A) modification on cancer biology

N6-methyladenosine (m6A), as the most abundant and well-known RNA modification, has been found to play an important role in cancer. Circular RNAs (circRNAs) are a class of single-stranded covalently closed RNA molecules generated by the reverse splicing process. Recent studies have revealed the vital roles of circRNAs in many diseases, including tumorigenesis. Accumulating evidence also shows an association between m6A modification and circRNAs. This study aimed to review the interactions between m6A modification and circRNAs and illustrate their roles in tumorigenesis. m6A modification can modulate the biogenesis, translation, cytoplasmic export, degradation, and other functions of circRNAs in different tumors. circRNAs can also modulate m6A modification by affecting writers, erasers, and readers. We focused on the potential regulatory mechanisms and the biological consequences of m6A modification of circRNAs, as well as the interactions in tumors of different systems. Finally, we listed the possible development directions of m6A modification and circRNAs, which might facilitate the clinical application of tumor therapy. AVAILABILITY OF DATA AND MATERIALS: Not applicable. Keywords.

HNRNPA2B1-Mediated MicroRNA-92a Upregulation and Section Acts as a Promising Noninvasive Diagnostic Biomarker in Colorectal Cancer

MicroRNA-92a (miR-92a) may serve as a novel promising biomarker in multiple cancers, including colorectal cancer (CRC); however, the diagnostic accuracy and the underlying molecular mechanism of miR-92a in CRC is poorly understood. We first carried out meta-analysis and found that serum/plasma miR-92a yield better diagnostic efficacy when compared to stool samples and CRC tissues, and this finding was validated by our independent study through stool sample. Multiple bioinformatics assay indicated that miR-92a expression was positively correlated with heterogeneous nuclear ribonucleoproteins A2/B1 (HNRNPA2B1) expression and closely related with the clinical characteristics of CRC. Experimental evidence showed that knockdown of HNRNPA2B1 could significantly decrease miR-92a expression and secretion in RKO cells. HNRNPA2B1 mediated miR-92a via m6A RNA modification. These findings indicate that HNRNPA2B1-m6A RNA modification-derived MicroRNA-92a upregulation and section from the local CRC acts a candidate noninvasive serum biomarker in colorectal cancer. Our study provides a novel insight into miR-92a mechanisms in relation to both expression and secretion for CRC diagnosis.

Prognostic values of the immune microenvironment-related non-coding RNA IGF2BP2-AS1 in bladder cancer

Bladder cancer can range from noninvasive to invasive tumors. When non-muscle invasive bladder cancer (NMIBC) recurs, patients could endure long-term invasive malignancies with a high disease-specific death rate. Immune escape frequently results in tumor development, metastases, unfavorable prognosis, and failure of immunotherapy. Based on the median immune score, this study used ESTIMATE scores to evaluate 411 bladder cancer cases from TCGA-BLCA. Two hundred two ncRNAs were differentially expressed in two groups, where 29 candidates appeared to be associated with the overall survival of bladder cancer patients. LASSO algorithm was performed to establish the risk score model of 13-ncRNA. Risk scores were computed for cases in the training set, validation set, and TCGA-BLCA set; Poor prognosis in cases with higher risk scores was based on the training set, validating set, and TCGA-BLCA set. Among the 13 ncRNAs, IGF2BP2-AS1, MAGF-AS1, ARHGAP5-AS1, and LINC00942 were significantly correlated with the overall survival of bladder cancer patients. Pearson's correlation analysis based on TCGA-BLCA identified 2093, 3107, 386, and 936 mRNAs co-expressed with IGF2BP2-AS1, MAGF-AS1, ARHGAP5-AS1, and LINC00942, respectively. Conclusively, the 13 ncRNA signature exhibited a feasible predictive prognostic value for bladder cancer patients. IGF2BP2-AS1 expression was higher in bladder cancer tissues and significantly correlated to immune-related factors, suggesting that IGF2BP2-AS1 represents a promising immune-related target for treating bladder cancer patients.

THE RELEVANCE OF RS6777038 AND RS6444082 OF IGF2BP2 GENE POLYMORPHISM AND TYPE 2 DIABETES MELLITUS: A CASE CONTROL STUDY

OBJECTIVE

The aim: We investigate IGF2BP2 gene polymorphisms (rs6777038 and rs6444082) association with T2DM of Iraqi sample.

PATIENTS AND METHODS

Materials and methods: The study involves 800 participants that divided to a healthy control group (400) and T2DM patients (400). Fasting blood sugar (FBS), triglycerides (Tgs), high-density lipoprotein cholesterol (HDL-Ch), total cholesterol (T-Ch), low-density lipoprotein cholesterol (LDL-Ch), and fasting insulin measured for both participant groups. IGF2BP2 gene has been genotyped for polymorphisms, rs6777038 and rs6444082 using the PCR-RFLP technique.

RESULTS

Results: Logistic regression analysis testing for rs6777038 revealed that the genotype and allele frequency differ significantly (p=0.009) between T2DM and control group. In codominant model, TT genotype carriers had higher risks for diabetes than control also in the recessive model TT genotype significantly had higher risk for diabetes than control group. The other models of rs6777038 failed to reveal significant differences. The rs6777038 genotypes as codominant model showed significant differences with phenotypic characters of BMI, insulin and HOMA-IR. As well as, this SNP as dominant model showed significant differences with fasting insulin and HOMA-IR. However, rs6444082 genotypes only as dominant model reveal significant variation with HOMA-IR.

CONCLUSION

Conclusions: This study confirmed the variant rs6777038 of IGF2BP2 possibly associated with T2DM risks and some anthropometric parameters such as lower fasting insulin, HOMA-IR and BMI in Iraqi T2DM participants.

LCAT1 is an oncogenic LncRNA by stabilizing the IGF2BP2-CDC6 axis

Long non-coding RNAs (lncRNAs) is known to play vital roles in modulating tumorigenesis. We previously reported that LCAT1, a novel lncRNA, promotes the growth and metastasis of lung cancer cells both in vitro and in vivo. However, the underlying mechanism(s) of LCAT1 as an oncogenic regulator remains elusive. Here, we showed that LCAT1 physically interacts with and stabilizes IGF2BP2, an m⁶A reader protein, by preventing its degradation via autolysosomes. IGF2BP2 is overexpressed in lung cancer tissues, which is associated with poor survival of non-small cell lung cancer patients, suggesting its oncogenic role. Biologically, IGF2BP2 depletion inhibits growth and survival as well as the migration of lung cancer cells. Mechanistically, the LCAT1/IGF2BP2 complex increased the levels of CDC6, a key cell cycle regulator, by stabilizing its mRNA in an m⁶A-dependent manner. Like IGF2BP2, CDC6 is also overexpressed in lung cancer tissues with poor patient survival, and CDC6 knockdown has oncogenic inhibitory activity. Taken together, the LCAT1-IGF2BP2-CDC6 axis appears to play a vital role in promoting the growth and migration of lung cancer cells, and is a potential therapeutic target for lung cancer. Importantly, our finding also highlights a previously unknown critical role of LCAT1 in m⁶A-dependent gene regulation by preventing autolytic degradation of IGF2BP2.

Research Progress for RNA Modifications in Physiological and Pathological Angiogenesis

As a critical layer of epigenetics, RNA modifications demonstrate various molecular functions and participate in numerous biological processes. RNA modifications have been shown to be essential for embryogenesis and stem cell fate. As high-throughput sequencing and antibody technologies advanced by leaps and bounds, the association of RNA modifications with multiple human diseases sparked research enthusiasm; in addition, aberrant RNA modification leads to tumor angiogenesis by regulating angiogenesis-related factors. This review collected recent cutting-edge studies focused on RNA modifications (N⁶-methyladenosine (m⁶A), N⁵-methylcytosine (m⁵C), N⁷-methylguanosine (m⁷G), N¹-methyladenosine (m¹A), and pseudopuridine (Ψ)), and their related regulators in tumor angiogenesis to emphasize the role and impact of RNA modifications.

Oncogenic Role of miR-217 During Clear Cell Renal Carcinoma Progression

Clear cell renal carcinoma (ccRC) comprises a set of heterogeneous, fast-progressing pathologies with poor prognosis. Analyzing ccRC progression in terms of modifications at the molecular level may provide us with a broader understanding of the disease, paving the way for improved diagnostics and therapeutics. The role of micro-RNAs (miRs) in cancer by targeting both oncogenes and tumor suppressor genes is widely known. Despite this knowledge, the role of specific miRs and their targets in the progression of ccRC is still unknown. To evaluate the action of miRs and their target genes during ccRC progression, here we implemented a three-step method for constructing miR–gene co-expression networks for each progression stage of ccRC as well as for adjacent-normal renal tissue (NT). In the first step, we inferred all miR–gene co-expression interactions for each progression stage of ccRC and for NT. Afterwards, we filtered the whole miR–gene networks by differential gene and miR expression between successive stages: stage I with non-tumor, stage II with stage I, and so on. Finally, all miR–gene interactions whose relationships were inversely proportional (overexpressed miR and underexpressed genes and vice versa) were kept and removed otherwise. We found that miR-217 is differentially expressed in all contrasts; however, its targets were different depending on the ccRC stage. Furthermore, the target genes of miR-217 have a known role in cancer progression—for instance, in stage II network, GALNTL6 is overexpressed, and it is related to cell signaling, survival, and proliferation. In the stage III network, WNK2, a widely known tumor suppressor, is underexpressed. For the stage IV network, IGF2BP2, a post-transcriptional regulator of MYC and PTEN, is overexpressed. This data-driven network approach has allowed us to discover miRs that have different targets through ccRC progression, thus providing a method for searching possible stage-dependent therapeutic targets in this and other types of cancer.

Augmentation of the RNA m6A reader signature is associated with poor survival by enhancing cell proliferation and EMT across cancer types

N⁶-Methyladenosine (m6A) RNA modification plays a critical role in the posttranscriptional regulation of gene expression. Alterations in cellular m6A levels and m6A-related genes have been reported in many cancers, but whether they play oncogenic or tumor-suppressive roles is inconsistent across cancer types. We investigated common features of alterations in m6A modification and m6A-related genes during carcinogenesis by analyzing transcriptome data of 11 solid tumors from The Cancer Genome Atlas database and our in-house gastric cancer cohort. We calculated m6A writer (W), eraser (E), and reader (R) signatures based on corresponding gene expression. Alterations in the W and E signatures varied according to the cancer type, with a strong positive correlation between the W and E signatures in all types. When the patients were divided according to m6A levels estimated by the ratio of the W and E signatures, the prognostic effect of m6A was inconsistent according to the cancer type. The R and especially the R2 signatures (based on the expression of IGF2BPs) were upregulated in all cancers. Patients with a high R2 signature exhibited poor prognosis across types, which was attributed to enrichment of cell cycle- and epithelial–mesenchymal transition-related pathways. Our study demonstrates common features of m6A alterations across cancer types and suggests that targeting m6A R proteins is a promising strategy for cancer treatment.

Studying the effects of a chemical modification of messenger RNA molecules (mRNA), which carry genetic information from DNA to the cell’s protein-making machinery, reveals new insights into the role of these modifications in cancer, suggesting potential therapeutic approaches. Researchers in Seoul, South Korea, led by Joon-Yong An at Korea University and Sung-Yup Cho at Seoul National University investigated the most common modifications of mRNA involving methyl groups (CH₃): addition (‘writing’), having a regulatory effect on the cell (‘reading’) or removal (‘erasing’). The molecular activities involved in reading the modifications were increased in all 11 types of cancer in cancer-sampling databases and their own patient cohort. Changes in writing and erasing of the modifications varied with cancer type. The proteins that mediate the reading responses to RNA methylation are possible targets for new anti-cancer drugs.

AGO-RBP crosstalk on target mRNAs: Implications in miRNA-guided gene silencing and cancer

MicroRNAs (miRNAs) and RNA-binding proteins (RBPs) are important regulators of mRNA translation and stability in eukaryotes. While miRNAs can only bind their target mRNAs in association with Argonaute proteins (AGOs), RBPs directly bind their targets either as single entities or in complex with other RBPs to control mRNA metabolism. miRNA binding in 3' untranslated regions (3' UTRs) of mRNAs facilitates an intricate network of interactions between miRNA-AGO and RBPs, thus determining the fate of overlapping targets. Here, we review the current knowledge on the interplay between miRNA-AGO and multiple RBPs in different cellular contexts, the rules underlying their synergism and antagonism on target mRNAs, as well as highlight the implications of these regulatory modules in cancer initiation and progression.

MicroRNAs Are Key Molecules Involved in the Gene Regulation Network of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common types of cancer and one of the leading causes of mortality worldwide. MicroRNAs (miRNAs) play central roles in normal cell maintenance, development, and other physiological processes. Growing evidence has illustrated that dysregulated miRNAs can participate in the initiation, progression, metastasis, and therapeutic resistance that confer miRNAs to serve as clinical biomarkers and therapeutic targets for CRC. Through binding to the 3′-untranslated region (3′-UTR) of target genes, miRNAs can lead to target mRNA degradation or inhibition at a post-transcriptional level. During the last decade, studies have found numerous miRNAs and their potential targets, but the complex network of miRNA/Targets in CRC remains unclear. In this review, we sought to summarize the complicated roles of the miRNA-target regulation network (Wnt, TGF-β, PI3K-AKT, MAPK, and EMT related pathways) in CRC with up-to-date, high-quality published data. In particular, we aimed to discuss the downstream miRNAs of specific pathways. We hope these data can be a potent supplement for the canonical miRNA-target regulation network.

A positive feedback loop between LINC01605 and NF-κB pathway promotes tumor growth in nasopharyngeal carcinoma

zong non-coding RNAs (lncRNAs) have been identified as crucial effector in modulating the progression of assorted malignancies. In our study, the main aim was to unveil the role and the underlying regulatory mechanism of long intergenic non-protein coding RNA 1605 (LINC01605) in nasopharyngeal carcinoma (NPC). RT-qPCR analysis results suggested that LINC01605 was upregulated in NPC cells. According to the results of function experiments, LINC01605 promoted NPC cell proliferation and impeded cell apoptosis. The oncogenic role of LINC01605 in NPC was further validated by animal experiments. Additionally, we verified that LINC01605 regulated Ikbkb expression to promote the nuclear translocation of p65 and thereby activated the NF-κB pathway in NPC cells. Mechanism experiments further suggested that LINC01605 could regulate Ikbkb expression via sponging miR-942-5p. Moreover, LINC01605 recruited IGF2BP2 to stabilize ubiquitin-specific protease 3 (USP3) mRNA and thereby enhanced the stability of IkB subunit beta (IKKβ) protein. In addition, p65 acted as a transcription activator to upregulate LINC01605 in NPC cells. In conclusion, this study demonstrated a positive feedback loop between LINC01605 and the NF-κB signalling pathway that promoted NPC cell growth, thus providing new insights to better understand NPC.

First Small-Molecule Inhibitors Targeting the RNA-Binding Protein IGF2BP2/IMP2 for Cancer Therapy

The RNA-binding protein IGF2BP2/IMP2/VICKZ2/p62 is overexpressed in several tumor entities, promotes tumorigenesis and tumor progression, and has been suggested to worsen the disease outcome. The aim of this study is to (I) validate IMP2 as a potential target for colorectal cancer, (II) set up a screening assay for small-molecule inhibitors of IMP2, and (III) test the biological activity of the obtained hit compounds. Analyses of colorectal and liver cancer gene expression data showed reduced survival in patients with a high IMP2 expression and in patients with a higher IMP2 expression in advanced tumors. In vitro target validation in 2D and 3D cell cultures demonstrated a reduction in cell viability, migration, and proliferation in IMP2 knockout cells. Also, xenotransplant tumor cell growth in vivo was significantly reduced in IMP2 knockouts. Different compound libraries were screened for IMP2 inhibitors using a fluorescence polarization assay, and the results were confirmed by the thermal shift assay and saturation-transfer difference NMR. Ten compounds, which belong to two classes, that is, benzamidobenzoic acid class and ureidothiophene class, were validated in vitro and showed a biological target specificity. The three most active compounds were also tested in vivo and exhibited reduced tumor xenograft growth in zebrafish embryos. In conclusion, our findings support that IMP2 represents a druggable target to reduce tumor cell proliferation.

Insulin-like growth factor 2 mRNA-binding protein 2-stabilized long non-coding RNA Taurine up-regulated gene 1 (TUG1) promotes cisplatin-resistance of colorectal cancer via modulating autophagy

Long non-coding RNAs (lncRNAs) have been demonstrated to influence the chemoresistance of colorectal cancer (CRC). Therefore, the study is designed to investigate the regulatory function and mechanism of Taurine up-regulated gene 1 (TUG1) in the cisplatin resistance of CRC. qRT-PCR checked the expressions of TUG1, Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), and miR-195-5p in CRC tissues and cells. The TUG1 or miR-195-5p overexpression model was engineered in CRC cells, followed by treatment with DDP or the autophagy inhibitor (Chloroquine, CQ). CCK8 (Cell Counting Kit-8) and the colony formation experiment monitored cell proliferation. Flow cytometry examined apoptosis, Transwell tracked migration and invasion, and Western blot ascertained the protein profiles of autophagy proteins (LC3I/LC3II and Beclin1) and the HDGF/DDX5/β-catenin pathway. Dual-luciferase gene reporter assay and RNA immunoprecipitation confirmed the binding correlation between TUG1 and miR-195-5p and between miR-195-5p and HDGF. Furthermore, in-vivo experiments in nude mice probed the function and mechanism of IGF2BP2 in CRC cell growth. The profiles of TUG1 and IGF2BP2 were elevated in CRC tissues, and IGF2BP2 enhanced TUG1's expression in CRC cells. TUG1 activated autophagy to facilitate CRC cells' resistance to DDP. TUG1 targets miR-195-5p, and miR-195-5p targets HDGF. Overexpression of miR-195-5p abated the cancer-promoting function of TUG1 and curbed the profile of the HDGF/DDX5/β-catenin axis. TUG1 stabilized by IGF2BP2 boosted CRC cell proliferation, migration, migration, and autophagy via the miR-195-5p/HDGF/DDX5/β-catenin axis, hence enhancing CRC cell's resistance to DDP.

Function of N6-Methyladenosine Modification in Tumors

N6-Methyladenosine (m6A) modification is a dynamic and reversible methylation modification at the N6-position of adenosine. As one of the most prevalent posttranscriptional methylation modifications of RNA, m6A modification participates in several mRNA processes, including nuclear export, splicing, translation, and degradation. Some proteins, such as METTL3, METTL14, WTAP, ALKBH5, FTO, and YTHDF1/2/3, are involved in methylation. These proteins are subdivided into writers (METTL3, METTL14, WTAP), erasers (ALKBH5, FTO), and readers (YTHDF1/2/3) according to their functions in m6A modification. Several studies have shown that abnormal m6A modification occurs in tumors, including colorectal cancer, liver cancer, breast cancer, nasopharyngeal carcinoma, and gastric cancer. The proteins for m6A modification are involved in tumor proliferation, angiogenesis, metastasis, immunity, and other processes. Herein, the roles of m6A modification in cancer are discussed, which will improve the understanding of tumorigenesis, as well as the diagnosis, treatment, and prognosis of tumors.

Stabilization of UCA1 by N6-methyladenosine RNA methylation modification promotes colorectal cancer progression

Background

UCA1 is frequently upregulated in a variety of cancers, including CRC, and it can play an oncogenic role by various mechanisms. However, how UCA1 is regulated in cancer is largely unknown. In this study, we aimed to determine whether RNA methylation at N6-methyladenosine (m6A) can impact UCA1 expression in colorectal cancer (CRC).

Methods

qRT-PCR was performed to detect the level of UCA1 and IGF2BP2 in CRC samples. CRISPR/Cas9 was employed to knockout (KO) UCA1, METTL3 and WTAP in DLD-1 and HCT-116 cells, while rescue experiments were carried out to re-express METTL3 and WTAP in KO cells. Immunoprecipitation using m6A antibody was performed to determine the m6A modification of UCA1. In vivo pulldown assays using S1m tagging combined with site-direct mutagenesis was carried out to confirm the recognition of m6A-modified UCA1 by IGF2BP2. Cell viability was measured by MTT and colony formation assays. The expression of UCA1 and IGF2BP2 in TCGA CRC database was obtained from GEPIA (http://gepia.cancer-pku.cn).

Results

Our results revealed that IGF2BP2 serves as a reader for m6A modified UCA1 and that adenosine at 1038 of UCA1 is critical to the recognition by IGF2BP2. Importantly, we showed that m6A writers, METTL3 and WTAP positively regulate UCA1 expression. Mechanically, IGF2BP2 increases the stability of m6A-modified UCA1. Clinically, IGF2BP2 is upregulated in CRC tissues compared with normal tissues.

Conclusion

These results suggest that m6A modification is an important factor contributing to upregulation of UCA1 in CRC tissues.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02288-x.

Insulin-like growth factor 2 mRNA binding protein 2 regulates proliferation, migration, and angiogenesis of keratinocytes by modulating heparanase stability

Wound healing is related to proliferation, migration, and angiogenesis of keratinocytes. Insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) is an important N6-methyladenosine (m6A) reader, which is involved in multiple processes, including wound healing. However, the function and mechanism of IGF2BP2 in keratinocyte processes are largely uncertain. In the present study, expression levels of IGF2BP2 and heparanase (HPSE) were detected by quantitative reverse transcription polymerase chain reaction and western blotting assays. Cell proliferation was investigated by cell counting kit-8 (CCK-8) analysis. Cell migration was determined through wound healing assay. Angiogenesis was measured by tube formation assay and vascular endothelial growth factor (VEGF) level using enzyme linked immunosorbent assay (ELISA). The interaction between IGF2BP2 and HPSE was analyzed by RNA immunoprecipitation, pull-down and luciferase reporter analyses. The results showed that IGF2BP2 expression was enhanced in wound healing. IGF2BP2 downregulation constrained HaCaT cell proliferation, migration, and angiogenesis. IGF2BP2 knockdown decreased HPSE expression. IGF2BP2 could regulate HPSE stability by binding with 3ʹ untranslated region (UTR) of HPSE. HPSE upregulation attenuated silencing IGF2BP2-mediated suppression of proliferation, migration, and angiogenesis. As a conclusion, IGF2BP2 knockdown repressed proliferation, migration, and angiogenesis of HaCaT cells by decreasing HPSE stability.

IGF2BP2 promotes the progression of colorectal cancer through a YAP-dependent mechanism

To explore the effect of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) on colorectal cancer (CRC) by recognizing the m6A modification of YAP mRNA thus activating ErbB2 expression. High expressions of IGF2BP2, YAP, and ErbB2 promoted the proliferation, migration and invasion of CRC cells and reduced their apoptosis. IGF2BP2 recognized the m6A on YAP mRNA and promoted the translation of mRNA. YAP regulated ErbB2 expression by promoting TEAD4 enrichment in ErbB2 promoter region. Therefore, IGF2BP2 promoted the expression of ErbB2 to enhance the proliferation, invasion and migration of CRC cells, to repress cell apoptosis, and to promote solid tumor formation in nude mice. IGF2BP2 activates the expression of ErbB2 by recognizing the m6A of YAP, thus affecting the cell cycle of CRC, inhibiting cell apoptosis, and promoting proliferation.

Insulin-like Growth Factor 2 mRNA-Binding Protein 2-a Potential Link Between Type 2 Diabetes Mellitus and Cancer

CONTEXT

Type 2 diabetes mellitus (T2DM) and cancer share a variety of risk factors and pathophysiological features. It is becoming increasingly accepted that the 2 diseases are related, and that T2DM increases the risk of certain malignancies.

OBJECTIVE

This review summarizes recent advancements in the elucidation of functions of insulin-like growth factor 2 (IGF-2) messenger RNA (mRNA)-binding protein 2 (IGF2BP2) in T2DM and cancer.

METHODS

A PubMed review of the literature was conducted, and search terms included IGF2BP2, IMP2, or p62 in combination with cancer or T2DM. Additional sources were identified through manual searches of reference lists. The increased risk of multiple malignancies and cancer-associated mortality in patients with T2DM is believed to be driven by insulin resistance, hyperinsulinemia, hyperglycemia, chronic inflammation, and dysregulation of adipokines and sex hormones. Furthermore, IGF-2 is oncogenic, and its loss-of-function splice variant is protective against T2DM, which highlights the pivotal role of this growth factor in the pathogenesis of these 2 diseases. IGF-2 mRNA-binding proteins, particularly IGF2BP2, are also involved in T2DM and cancer, and single-nucleotide variations (formerly single-nucleotide polymorphisms) of IGF2BP2 are associated with both diseases. Deletion of the IGF2BP2 gene in mice improves their glucose tolerance and insulin sensitivity, and mice with transgenic p62, a splice variant of IGF2BP2, are prone to diet-induced fatty liver disease and hepatocellular carcinoma, suggesting the biological significance of IGF2BP2 in T2DM and cancer.

CONCLUSION

Accumulating evidence has revealed that IGF2BP2 mediates the pathogenesis of T2DM and cancer by regulating glucose metabolism, insulin sensitivity, and tumorigenesis. This review provides insight into the potential involvement of this RNA binding protein in the link between T2DM and cancer.

Bioinformatical identification of key genes regulated by IGF2BP2-mediated RNA N6-methyladenosine and prediction of prognosis in hepatocellular carcinoma

Background

The treatment of hepatocellular carcinoma (HCC), a malignant cancer with global spread, remains unsatisfactory, and novel prognostic biomarkers need to be identified. N6-methyladenosine (m⁶A) has been found to regulate tumor initiation and progression through different mechanisms. As a dynamic and reversible messenger RNA (mRNA) modification, m⁶A can be read by insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). IGF2BP2 targets thousands of mRNA transcripts, which may be involved in HCC progression.

Methods

In this study, we integrated 4 classes of datasets including The Cancer Genome Atlas (TCGA)-LICH, m⁶A-sequencing data of HepG2 cells, and RNA-sequencing data of IGF2BP2-knockdown HepG2 cells to explore the key genes regulated by IGF2BP2-mediated m⁶A in HCC. The expression and m⁶A modification of candidates were validation in independent microarray expression profile of HCC tissue and annotated m⁶A database RMBase. The relationship of immune cell infiltration and the genes expression was estimated by CIBERSORT and TIMER.

Results

A total of 89 candidate genes were filtered. Next, cluster analysis was performed base on functions and pathways to identify the enrichment pathways. By constructing a protein-protein interaction (PPI) network, we found 54 nodes. Ten significant genes were filtered from the PPI. These genes were validated in data of an independent microarray and an m⁶A database. We found that the upregulation of these 10 genes was associated with poor prognosis. In addition, we showed the expression of these 10 genes was associated with the infiltration of variety of immune cell and tumor purity.

Conclusions

These identified genes may provide novel insights and facilitate the development of potential biomarkers for HCC diagnosis, as well as provide clues for IGF2BP2 inhibition therapy in HCC.

Identification and Validation of Esophageal Squamous Cell Carcinoma Targets for Fluorescence Molecular Endoscopy

Dysplasia and intramucosal esophageal squamous cell carcinoma (ESCC) frequently go unnoticed with white-light endoscopy and, therefore, progress to invasive tumors. If suitable targets are available, fluorescence molecular endoscopy might be promising to improve early detection. Microarray expression data of patient-derived normal esophagus (n = 120) and ESCC samples (n = 118) were analyzed by functional genomic mRNA (FGmRNA) profiling to predict target upregulation on protein levels. The predicted top 60 upregulated genes were prioritized based on literature and immunohistochemistry (IHC) validation to select the most promising targets for fluorescent imaging. By IHC, GLUT1 showed significantly higher expression in ESCC tissue (30 patients) compared to the normal esophagus adjacent to the tumor (27 patients) (p < 0.001). Ex vivo imaging of GLUT1 with the 2-DG 800CW tracer showed that the mean fluorescence intensity in ESCC (n = 17) and high-grade dysplasia (HGD, n = 13) is higher (p < 0.05) compared to that in low-grade dysplasia (LGD) (n = 7) and to the normal esophagus adjacent to the tumor (n = 5). The sensitivity and specificity of 2-DG 800CW to detect HGD and ESCC is 80% and 83%, respectively (ROC = 0.85). We identified and validated GLUT1 as a promising molecular imaging target and demonstrated that fluorescent imaging after topical application of 2-DG 800CW can differentiate HGD and ESCC from LGD and normal esophagus.

FTO downregulation mediated by hypoxia facilitates colorectal cancer metastasis

Fat mass and obesity-associated protein (FTO), an N6-methyladenosine (m6A) demethylase, participates in tumor progression and metastasis in many malignancies, but its role in colorectal cancer (CRC) is still unclear. Here, we found that FTO protein levels, but not RNA levels, were downregulated in CRC tissues. Reduced FTO protein expression was correlated with a high recurrence rate and poor prognosis in resectable CRC patients. Moreover, we demonstrated that hypoxia restrained FTO protein expression, mainly due to an increase in ubiquitin-mediated protein degradation. The serine/threonine kinase receptor associated protein (STRAP) might served as the E3 ligase and K216 was the major ubiquitination site responsible for hypoxia-induced FTO degradation. FTO inhibited CRC metastasis both in vitro and in vivo. Mechanistically, FTO exerted a tumor suppressive role by inhibiting metastasis-associated protein 1 (MTA1) expression in an m6A-dependent manner. Methylated MTA1 transcripts were recognized by an m6A "reader", insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), which then stabilized its mRNA. Together, our findings highlight the critical role of FTO in CRC metastasis and reveal a novel epigenetic mechanism by which the hypoxic tumor microenvironment promotes CRC metastasis.

IGF2BP2 knockdown suppresses thyroid cancer progression by reducing the expression of long non-coding RNA HAGLR

BACKGROUND

N6-methyladenosine (m6A), a common internal modification on RNAs, has been found to be closely linked with RNA biosynthesis/metabolism and cancer development. In this text, the roles and molecular mechanisms of m6A-bind protein IGF2BP2 in the development of thyroid cancer (TC) were investigated in vitro.

METHODS

IGF2BP2 and lncRNA HAGLR were screened out through multiple public databases such as TCGA, Ualcan, POSTAR2, Starbase, and GEPIA. Cell proliferative, migratory and invasive abilities were assessed by CCK-8, Transwell migration and invasion assays, respectively. Cell cycle distribution and cell apoptotic patterns were measured by flow cytometry. The interaction between HAGLR and IGF2BP2 was examined by RIP, RNA pull-down and luciferase assays and bioinformatics analysis. The effect of IGF2BP2 knockdown on the m6A level of HAGLR was explored by meRIP assay.

RESULTS

IGF2BP2 was highly expressed in TC tumor tissues. IGF2BP2 knockdown weakened cell proliferative, migratory, and invasive abilities, and induced cell cycle arrest and cell apoptosis in TC cells. LncRNA HAGLR expression was markedly upregulated and positively associated with IGF2BP2 expression in TC tissues. IGF2BP2 knockdown reduced HAGLR expression and transcript stability in TC cells. IGF2BP2 regulated HAGLR expression in an m6A-dependent manner. HAGLR overexpression weakened the effects of IGF2BP2 loss on cell proliferation, migration, invasion, apoptosis, and cell cycle progression in TC cells.

CONCLUSION

IGF2BP2 loss inhibited cell proliferation, migration and invasion, and induced cell apoptosis and cell cycle arrest by down-regulating HAGLR expression in an m6A-dependent manner in TC cells, providing some potential diagnostic and therapeutic targets for TC.

The biological function of IGF2BPs and their role in tumorigenesis

The insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) pertain to a highly conservative RNA-binding family that works as a post-transcriptional fine-tuner for target transcripts. Emerging evidence suggests that IGF2BPs regulate RNA processing and metabolism, including stability, translation, and localization, and are involved in various cellular functions and pathophysiologies. In this review, we summarize the roles and molecular mechanisms of IGF2BPs in cancer development and progression. We mainly discuss the functional relevance of IGF2BPs in embryo development, neurogenesis, metabolism, RNA processing, and tumorigenesis. Understanding IGF2BPs role in tumor progression will provide new insight into cancer pathophysiology.

m6A modification promotes miR-133a repression during cardiac development and hypertrophy via IGF2BP2

Both N6-methyladenosine (m6A) RNA modification and microRNAs (miRNAs) are common regulatory mechanisms for gene post-transcription by modulating mRNA stability and translation. They also share the same 3′-untranslated regions (UTRs) regions for their target gene. However, little is known about their potential interaction in cell development and biology. Here, we aimed to investigate how m6A regulates the specific miRNA repression during cardiac development and hypertrophy. Our multiple lines of bioinformatic and molecular biological evidence have shown that m6A modification on cardiac miR-133a target sequence promotes miR-133a repressive effect via AGO2-IGF2BP2 (Argonaute 2—Insulin-like growth factor 2 mRNA binding protein 2) complex. Among 139 cardiac miRNAs, only the seed sequence of miR-133a was inversely complement to m6A consensus motif “GGACH” by sequence alignment analysis. Immunofluorescence staining, luciferase reporter, and m6A-RIP (RNA immunoprecipitation) assays revealed that m6A modification facilitated miR-133a binding to and repressing their targets. The inhibition of the miR-133a on cardiac proliferation and hypertrophy could be prevented by silencing of Fto (FTO alpha-ketoglutarate dependent dioxygenase) which induced m6A modification. IGF2BP2, an m6A binding protein, physically interacted with AGO2 and increased more miR-133a accumulation on its target site, which was modified by m6A. In conclusion, our study revealed a novel and precise regulatory mechanism that the m6A modification promoted the repression of specific miRNA during heart development and hypertrophy. Targeting m6A modification might provide a strategy to repair hypertrophic gene expression induced by miR-133a.

RNA-Binding Protein Polymorphisms as Novel Biomarkers to Predict Outcomes of Metastatic Colorectal Cancer: A Meta-analysis from TRIBE, FIRE-3, and MAVERICC

RNA-binding proteins (RBPs) regulate many posttranscriptional cellular activities. Accumulating evidence suggests associations between RBPs with colonic tumorigenesis and chemosensitivity. We investigated the prognostic and predictive values of SNPs of genes encoding RBPs in metastatic colorectal cancer (mCRC), using clinical and genomic data from three randomized clinical trials of standard first-line chemotherapy for mCRC (TRIBE, FIRE-3, and MAVERICC). Genomic DNA extracted from blood samples was genotyped using an OncoArray. We tested 30 candidate SNPs of 10 major RBP-related genes with additive models. Prognostic values were estimated by meta-analysis approach. Treatment-by-SNP interactions were tested to estimate predictive values for targeted drugs and cytotoxic backbone chemotherapies. This study included 884 patients. The meta-analysis revealed prognostic values of LIN28B rs314277 [HR, 1.26; 95% confidence interval (CI), 1.06-1.49, P = 0.005, FDR-adjusted P = 0.072 for overall survival (OS)] and LIN28B rs314276 (HR, 1.25; 95% CI, 1.08-1.44, P = 0.002, FDR-adjusted P = 0.062 for OS). Although some SNPs showed potentially predictive values, these associations were not confirmed after FDR adjustment. In conclusion, the results of this study are warranting additional studies to provide the evidence that RBP-related SNPs may be associated with the prognosis of patients with mCRC treated with standard first-line chemotherapies. In addition, further studies are warranted to study the predictive value.

Genomic relevance of FGF14 and associated genes on the prognosis of pancreatic cancer

BACKGROUND

Fibroblast (FGFs) and insulin (IGF) growth factor pathways are among 10 most recurrently altered genomic pathways in pancreatic ductal adenocarcinoma (PDAC). However, the prognostic and therapeutic relevance of FGF and IGF pathways in PDAC is largely unknown.

METHODS

We investigated the relationship between fibroblast and insulin pathway gene expression and clinicopathological features in three independent transcriptomic cohorts of 532 PDAC patients. Furthermore, we have examined the coexpressed genes specific to the prognostic marker identified from these cohorts. Statistical tests including Fisher-exact\Chi-square, Kaplan-Meier, Pearson Correlation and cox regression analyses were performed. Additionally, pathway analysis of gene-specific co-expressed genes was also performed.

RESULTS

The dysregulation of six genes including FGF9, FGF14, FGFR1, FGFR4, IGF2BP2 and IGF2BP3 were significantly associated with different clinical characteristics (including grade, stage, recurrence and nodes) in PDAC cohorts. 11 genes (including FGF9, FGF13, FGF14, FGF17, FGFR1, FGFRL1, FGFBP3, IGFBP3, IGF2BP2, IGF2BP3 and IGFBPL1) showed association with overall survival in different PDAC cohorts. Interestingly, overexpression of FGF14 was found associated with better overall survival (OS) in all three cohorts. Of note, multivariate analysis also revealed FGF14 as an independent prognostic marker for better OS in all three cohorts. Furthermore, FMN2 and PGR were among the top genes that correlated with FGF14 in all 3 cohorts. Of note, overexpression of FMN2 and PGR was found significantly associated with good overall survival in PDAC patients, suggesting FMN2 and PGR can also act as potential markers for the prediction of prognosis in PDAC patients.

CONCLUSION

FGF14 may define a distinct subset of PDAC patients with better prognosis. Moreover, FGF14-based sub-classification of PDAC suggests that FMN2 and PGR can be employed as good prognostic markers in PDAC and this classification may lead to new therapeutic approaches.

The Interplay Between Non-coding RNAs and Insulin-Like Growth Factor Signaling in the Pathogenesis of Neoplasia

The insulin-like growth factors (IGFs) are polypeptides with similar sequences with insulin. These factors regulate cell growth, development, maturation, and aging via different processes including the interplay with MAPK, Akt, and PI3K. IGF signaling participates in the pathogenesis of neoplasia, insulin resistance, diabetes mellitus, polycystic ovarian syndrome, cerebral ischemic injury, fatty liver disease, and several other conditions. Recent investigations have demonstrated the interplay between non-coding RNAs and IGF signaling. This interplay has fundamental roles in the development of the mentioned disorders. We designed the current study to search the available data about the role of IGF-associated non-coding RNAs in the evolution of neoplasia and other conditions. As novel therapeutic strategies have been designed for modification of IGF signaling, identification of the impact of non-coding RNAs in this pathway is necessary for the prediction of response to these modalities.

The role of IGF2BP2, an m6A reader gene, in human metabolic diseases and cancers

The human insulin-like growth factor 2 (IGF2) mRNA binding proteins 2 (IGF2BP2/IMP2) is an RNA-binding protein that regulates multiple biological processes. Previously, IGF2BP2 was thought to be a type 2 diabetes (T2D)-associated gene. Indeed IGF2BP2 modulates cellular metabolism in human metabolic diseases such as diabetes, obesity and fatty liver through post-transcriptional regulation of numerous genes in multiple cell types. Emerging evidence shows that IGF2BP2 is an N6-methyladenosine (m6A) reader that participates in the development and progression of cancers by communicating with different RNAs such as microRNAs (miRNAs), messenger RNAs (mRNAs) and long non-coding RNAs (lncRNAs). Additionally, IGF2BP2 is an independent prognostic factor for multiple cancer types. In this review, we summarize the current knowledge on IGF2BP2 with regard to diverse human metabolic diseases and its potential for cancer prognosis.