M6A associated TSUC7 inhibition contributed to Erlotinib resistance in lung adenocarcinoma through a notch signaling activation dependent way

Association between methyltransferase-like 3 and non-small cell lung cancer: pathogenesis, therapeutic resistance, and clinical applications

Non-small cell lung cancer (NSCLC) is a malignant cancer that with high incidence, recurrence, and mortality rates in human beings, posing significant threats to human health. Moreover, effective early diagnosis of NSCLC remains limited primarily by the lack of accurate biomarkers. Therefore, there is an urgent need to understand the mechanisms underlying NSCLC pathogenesis and treatment failure. Methyltransferase-like 3 (METTL3) is a prototypical member of a family of which its members transfer methyl groups. It has been implicated in modulating the pathogenesis of NSCLC, as well as conferring resistance to NSCLC therapeutics. The targeting of METTL3 for NSCLC treatment has been reported. However, the relationship between METTL3 and NSCLC remains to be demonstrated. In this review, we discuss relevant interrelationships by summarising the studies on METTL3 in NSCLC pathogenesis, therapeutic resistance, and clinical applications. Current research suggests that the upregulation of METTL3 expression propels the tumorigenesis, progression, and treatment resistance of NSCLC. Therefore, we propose that METTL3 is an excellent candidate biomarker for NSCLC diagnosis and prognosis. Therapeutic targeting of METTL3 has significant potential for NSCLC treatment. This review provides a summary of the association between METTL3 and NSCLC, which would be a valuable reference for both basic and clinical research.

HOPEXGB: A Consensual Model for Predicting miRNA/lncRNA-Disease Associations Using a Heterogeneous Disease-miRNA-lncRNA Information Network

Predicting disease-related microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) is crucial to find new biomarkers for the prevention, diagnosis, and treatment of complex human diseases. Computational predictions for miRNA/lncRNA-disease associations are of great practical significance, since traditional experimental detection is expensive and time-consuming. In this paper, we proposed a consensual machine-learning technique-based prediction approach to identify disease-related miRNAs and lncRNAs by high-order proximity preserved embedding (HOPE) and eXtreme Gradient Boosting (XGB), named HOPEXGB. By connecting lncRNA, miRNA, and disease nodes based on their correlations and relationships, we first created a heterogeneous disease-miRNA-lncRNA (DML) information network to achieve an effective fusion of information on similarities, correlations, and interactions among miRNAs, lncRNAs, and diseases. In addition, a more rational negative data set was generated based on the similarities of unknown associations with the known ones, so as to effectively reduce the false negative rate in the data set for model construction. By 10-fold cross-validation, HOPE shows better performance than other graph embedding methods. The final consensual HOPEXGB model yields robust performance with a mean prediction accuracy of 0.9569 and also demonstrates high sensitivity and specificity advantages compared to lncRNA/miRNA-specific predictions. Moreover, it is superior to other existing methods and gives promising performance on the external testing data, indicating that integrating the information on lncRNA-miRNA interactions and the similarities of lncRNAs/miRNAs is beneficial for improving the prediction performance of the model. Finally, case studies on lung, stomach, and breast cancers indicate that HOPEXGB could be a powerful tool for preclinical biomarker detection and bioexperiment preliminary screening for the diagnosis and prognosis of cancers. HOPEXGB is publicly available at https://github.com/airpamper/HOPEXGB.

Comprehensive landscape and future perspective of long noncoding RNAs in non-small cell lung cancer: it takes a village

Long noncoding RNAs (lncRNAs) are a distinct subtype of RNA that lack protein-coding capacity but exert significant influence on various cellular processes. In non-small cell lung cancer (NSCLC), dysregulated lncRNAs act as either oncogenes or tumor suppressors, contributing to tumorigenesis and tumor progression. LncRNAs directly modulate gene expression, act as competitive endogenous RNAs by interacting with microRNAs or proteins, and associate with RNA binding proteins. Moreover, lncRNAs can reshape the tumor immune microenvironment and influence cellular metabolism, cancer cell stemness, and angiogenesis by engaging various signaling pathways. Notably, lncRNAs have shown great potential as diagnostic or prognostic biomarkers in liquid biopsies and therapeutic strategies for NSCLC. This comprehensive review elucidates the significant roles and diverse mechanisms of lncRNAs in NSCLC. Furthermore, we provide insights into the clinical relevance, current research progress, limitations, innovative research approaches, and future perspectives for targeting lncRNAs in NSCLC. By summarizing the existing knowledge and advancements, we aim to enhance the understanding of the pivotal roles played by lncRNAs in NSCLC and stimulate further research in this field. Ultimately, unraveling the complex network of lncRNA-mediated regulatory mechanisms in NSCLC could potentially lead to the development of novel diagnostic tools and therapeutic strategies.

New understandings of the genetic regulatory relationship between non-coding RNAs and m6A modification

One of the most frequent epigenetic modifications of RNA in eukaryotes is N6 methyladenosine (m6A), which is mostly present in messenger RNAs. Through the influence of several RNA processing stages, m6A modification is a crucial approach for controlling gene expression, especially in cancer progression. It is universally acknowledged that numerous non-coding RNAs (ncRNAs), such as microRNAs, circular RNAs, long non-coding RNAs, and piRNAs, are also significantly affected by m6A modification, and the complex genetic regulatory relationship between m6A and ncRNAs plays a pivotal role in the development of cancer. The connection between m6A modifications and ncRNAs offers an opportunity to explore the oncogene potential regulatory mechanisms and suggests that m6A modifications and ncRNAs could be vital biomarkers for multiple cancers. In this review, we discuss the mechanisms of interaction between m6A methylation and ncRNAs in cancer, and we also summarize diagnostic and prognostic biomarkers for clinical cancer detection. Furthermore, our article includes some methodologies for identifying m6A sites when assessing biomarker potential.

The critical roles of m6A RNA methylation in lung cancer: from mechanism to prognosis and therapy

Lung cancer, a highly malignant disease, greatly affects patients' quality of life. N6-methyladenosine (m6A) is one of the most common posttranscriptional modifications of various RNAs, including mRNAs and ncRNAs. Emerging studies have demonstrated that m6A participates in normal physiological processes and that its dysregulation is involved in many diseases, especially pulmonary tumorigenesis and progression. Among these, regulators including m6A writers, readers and erasers mediate m6A modification of lung cancer-related molecular RNAs to regulate their expression. Furthermore, the imbalance of this regulatory effect adversely affects signalling pathways related to lung cancer cell proliferation, invasion, metastasis and other biological behaviours. Based on the close association between m6A and lung cancer, various prognostic risk models have been established and novel drugs have been developed. Overall, this review comprehensively elaborates the mechanism of m6A regulation in the development of lung cancer, suggesting its potential for clinical application in the therapy and prognostic assessment of lung cancer.

Enhancement of TKI sensitivity in lung adenocarcinoma through m6A-dependent translational repression of Wnt signaling by circ-FBXW7

BACKGROUND

Tyrosine kinase inhibitors (TKIs) that specifically target mutational points in the EGFR gene have significantly reduced suffering and provided greater relief to patients with lung adenocarcinoma (LUAD). The third-generation EGFR-TKI, Osimertinib, has been successfully employed in clinical treatments to overcome resistance to both original and acquired T790M and L858R mutational points. Nevertheless, the issue of treatment failure response has emerged as an insurmountable problem.

METHODS

By employing a combination of multiple and integrated approaches, we successfully identified a distinct population within the tumor group that plays a significant role in carcinogenesis, resistance, and recurrence. Our research suggests that addressing TKI resistance may involve targeting the renewal and repopulation of stem-like cells. To investigate the underlying mechanisms, we conducted RNA Microarray and m6A Epi-Transcriptomic Microarray analyses, followed by assessment of transcription factors. Additionally, we specifically designed a tag to detect the polypeptide circRNA-AA, and its expression was confirmed through m6A regulations.

RESULTS

We initially identified unique molecular signatures present in cancer stem cells that contributed to poor therapeutic responses. Activation of the alternative Wnt pathway was found to sustain the renewal and resistant status of these cells. Through bioinformatics analysis and array studies, we observed a significant decrease in the expression of circFBXW7 in Osimertinib-resistant cell lines. Notably, the abnormal expression pattern of circFBXW7 determined the cellular response to Osimertinib. Functional investigations revealed that circFBXW7 inhibits the renewal of cancer stem cells and resensitizes both resistant LUAD cells and stem cells to Osimertinib. In terms of the underlying mechanism, we discovered that circFBXW7 can be translated into short polypeptides known as circFBXW7-185AA. These polypeptides interact with β-catenin in an m6A-dependent manner. This interaction leads to reduced stability of β-catenin by inducing subsequent ubiquitination, thereby suppressing the activation of canonical Wnt signaling. Additionally, we predicted that the m6A reader, YTHDF3, shares common binding sites with hsa-Let-7d-5p. Enforced expression of Let-7d post-transcriptionally decreases the levels of YTHDF3. The repression of Let-7d by Wnt signaling releases the stimulation of m6A modification by YTHDF3, promoting the translation of circFBXW7-185AA. This creates a positive feedback loop contributing to the cascade of cancer initiation and promotion.

CONCLUSIONS

Our bench study, in vivo experiments, and clinical validation have unequivocally shown that circFBXW7 effectively inhibits the abilities of LUAD stem cells and reverses resistance to TKIs by modulating Wnt pathway functions through the action of circFBXW7-185AA on β-catenin ubiquitination and inhibition. The regulatory role of circRNA in Osimertinib treatment has been rarely reported, and our findings reveal that this process operates under the influence of m6A modification. These results highlight the tremendous potential of this approach in enhancing therapeutic strategies and overcoming resistance to multiple TKI treatments.

The role of m6A methylation in therapy resistance in cancer

Cancer therapy resistance is the main cause of cancer treatment failure. The mechanism of therapy resistance is a hot topic in epigenetics. As one of the most common RNA modifications, N6-methyladenosine (m6A) is involved in various processes of RNA metabolism, such as stability, splicing, transcription, translation, and degradation. A large number of studies have shown that m6A RNA methylation regulates the proliferation and invasion of cancer cells, but the role of m6A in cancer therapy resistance is unclear. In this review, we summarized the research progress related to the role of m6A in regulating therapy resistance in cancers.

Regulatory network and targeted interventions for CCDC family in tumor pathogenesis

CCDC (coiled-coil domain-containing) is a coiled helix domain that exists in natural proteins. There are about 180 CCDC family genes, encoding proteins that are involved in intercellular transmembrane signal transduction and genetic signal transcription, among other functions. Alterations in expression, mutation, and DNA promoter methylation of CCDC family genes have been shown to be associated with the pathogenesis of many diseases, including primary ciliary dyskinesia, infertility, and tumors. In recent studies, CCDC family genes have been found to be involved in regulation of growth, invasion, metastasis, chemosensitivity, and other biological behaviors of malignant tumor cells in various cancer types, including nasopharyngeal carcinoma, lung cancer, colorectal cancer, and thyroid cancer. In this review, we summarize the involvement of CCDC family genes in tumor pathogenesis and the relevant upstream and downstream molecular mechanisms. In addition, we summarize the potential of CCDC family genes as tumor therapy targets. The findings discussed here help us to further understand the role and the therapeutic applications of CCDC family genes in tumors.

Long non-coding RNA TDRG1 aggravates lung cancer stemness by binding to Sox2 mRNA

The roles of long non-coding RNA TDRG1 have been revealed in several tumors, especially its roles in CSC progression have been recently elucidated; However, its effects in lung CSC progression have not been revealed. In the present study, we collected 3D non-adherent spheres as the CSC model to measure lncRNA TDRG1 level in lung CSC and the parental lung cancer cells, and found that TDRG1 level was significantly upregulated in lung CSCs compared to that of parental lung cancer cells. Then we constructed the lung CSCs with or without TDRG1 stable knockdown and lung cancer cells with or without TDRG1 stable overexpression. It was found that TDRG1 positively regulated lung cancer stemness. Mechanistically, we identified that TDRG1 directly bound to Sox2 mRNA, which is a critical stemness regulator, enhanced its mRNA stability, and thus increased Sox2 expression. Indeed, we demonstrated that TDRG1 aggravated lung cancer stemness dependent on Sox2 expression. Thus, this study suggests that TDRG1 is a critical stemness promoter of lung cancer cells by acting as a stabilizer for Sox2 mRNA.

Emerging roles of m6A RNA modification in cancer therapeutic resistance

Marvelous advancements have been made in cancer therapies to improve clinical outcomes over the years. However, therapeutic resistance has always been a major difficulty in cancer therapy, with extremely complicated mechanisms remain elusive. N6-methyladenosine (m6A) RNA modification, a hotspot in epigenetics, has gained growing attention as a potential determinant of therapeutic resistance. As the most prevalent RNA modification, m6A is involved in every links of RNA metabolism, including RNA splicing, nuclear export, translation and stability. Three kinds of regulators, "writer" (methyltransferase), "eraser" (demethylase) and "reader" (m6A binding proteins), together orchestrate the dynamic and reversible process of m6A modification. Herein, we primarily reviewed the regulatory mechanisms of m6A in therapeutic resistance, including chemotherapy, targeted therapy, radiotherapy and immunotherapy. Then we discussed the clinical potential of m6A modification to overcome resistance and optimize cancer therapy. Additionally, we proposed existing problems in current research and prospects for future research.

Downregulation of Linc00173 increases BCL2 mRNA stability via the miR-1275/PROCA1/ZFP36L2 axis and induces acquired cisplatin resistance of lung adenocarcinoma

BACKGROUND

LINC00173 had been reported as a cisplatin (cis-diamminedichloroplatinum, DDP) chemotherapy-resistant inducer in small-cell lung cancer (SCLC) and lung squamous cell carcinoma (LUSC). This study aimed to display reverse data for LINC00173 as a DDP chemosensitivity-inducing factor in lung adenocarcinoma (LUAD).

METHODS

LINC00173 was screened from the Gene Expression Omnibus database (GSE43493). The expression level of LINC00173 in LUAD tissues and cell lines was detected using in situ hybridization and quantitative reverse transcription-polymerase chain reaction. Colony formation, cell viability, half-maximal inhibitory concentration, flow cytometry, and xenograft mouse model were used to evaluate the role of LINC00173 in the chemosensitivity of LUAD to DDP. The mechanism of LINC00173 in DDP resistance by mediating miR-1275/PROCA1/ZFP36L2 axis to impair BCL2 mRNA stability was applied, and co-immunoprecipitation, chromatin immunoprecipitation, RNA antisense purification, RNA immunoprecipitation, and luciferase reporter assays were performed.

RESULTS

LINC00173 downregulation in patients with DDP-resistant LUAD was correlated with poor prognosis. Further, LINC00173 expression was significantly reduced in DDP-resistant LUAD cells and DDP-treated human LUAD tissues. Suppressed LINC00173 expression in LUAD cells enhanced DDP chemoresistance in vivo and in vitro, while restored LINC00173 expression in DDP-resistant LUAD cells markedly regained chemosensitivity to DDP. Mechanistically, DDP-resistant LUAD cells activated PI3K/AKT signal and further elevated the c-Myc expression. The c-Myc, as an oncogenic transcriptional factor, bound to the promoter of LINC00173 and suppressed its expression. The reduced LINC00173 expression attenuated the adsorption of oncogenic miR-1275, downregulating the expression of miR-1275 target gene PROCA1. PROCA1 played a potential tumor-suppressive role inducing cell apoptosis and DDP chemosensitivity via recruiting ZFP36L2 to bind to the 3' untranslated region of BCL2, reducing the stability of BCL2 mRNA and thus activating the apoptotic signal.

CONCLUSIONS

This study demonstrated a novel and critical role of LINC00173. It was transcriptionally repressed by DDP-activated PI3K/AKT/c-Myc signal in LUAD, promoting DDP-acquired chemotherapeutic resistance by regulating miR-1275 to suppress PROCA1/ZFP36L2-induced BCL2 degradation, which led to apoptotic signal reduction. These data were not consistent with the previously described role of LINC00173 in SCLC or LUSC, which suggested that LINC00173 could play fine-tuned DDP resistance roles in different pathological subtypes of lung cancer. This study demonstrated that the diminished expression of LINC00173 might serve as an indicator of DDP-acquired resistance in LUAD.

Targeting cancer stem cell pathways for lung cancer therapy

PURPOSE OF REVIEW

The unique properties of cancer stem cells (CSCs) make lung cancer untargetable for quite an extended period. The functional mechanism of this cell type has been illustrated step by step. However, the outcomes of lung cancer patients are still lower than expected clinically. The attempts made by scientists to make challenge history against stemness maintenance of lung cancer cells and their druggable targets are worth elucidating.

RECENT FINDINGS

Many agents, including the Bispecific T-cell engager (BiTE) and AMG 119 targeting DLL3-positive cells, are a tremendous breakthrough in the preclinical and clinical treatment of SCLC. More studies focus on targeting CSCs to overcome TKI resistance in NSCLC. The combo targeting of CSC and the immune microenvironment can favor the treatment of lung cancer patients.

SUMMARY

The current review elucidates the characteristics and related regulating pathways of lung CSCs from essential to preclinical research. We retrospectively introduce an update on the clinical development of therapeutics targeting CSC-associated developmental signaling pathways and discuss the opportunities to target CSC-immune interactions in lung cancer.

Stem signatures associating SOX2 antibody helps to define diagnosis and prognosis prediction with esophageal cancer

BACKGROUND

esophageal cancer is one of the deadliest diseases worldwide. Due to the ineffectual screening methods referring to early diagnosis, most people have lost their chance of radical resection when diagnosed with esophageal cancer. This aim of this study was designed to evaluate the latent values of the stem signatures-associated autoantibodies (AABS) in predicting the early diagnosis, and particularly seeking the precise predictive outcomes with sensitive SOX2. We also studied the potential immunotherapeutic targets and prospective long-term prognosis predicators of esophageal cancer.

METHODS

The serum concentrations of selective antibodies were quantitated by enzyme-linked immunosorbent assay (ELISA), and a total of 203 local cases were enrolled. The TCGA databases were used to analyse distinct expression patterns and prognostic values of related genes. The TIMER database was used to explore the signatures of immune cell infiltration in related genes. The TISIDB database was used to analyse the association between related genes and immune regulators.

RESULTS

The stem signatures-associated with antibodies of TP53, PGP9.5, SOX2, and CAGE were highly expressed in esophageal cancer and were negatively correlated with the test group, the diagnostic sensitivity of P53, SOX2, PGP9.5 and CAGE reached to 54.3%, 56.5%, 80.4% and 47.8%, respectively, and the specificity reached 77.7%, 93.6%, 76.4% and 86.6%. Especially in stage I esophageal cancer, the diagnostic sensitivity of SOX2 reached 82.4% with a specificity of 85.4%, which demonstrated good value in early diagnosis.

CONCLUSIONS

The stem signatures-associated antibodies could be used as an effective indicator in early esophageal cancer diagnosis and could help to precisely predicate survival and prognosis.Key MessagesThe stem signatures-associated immune-antibodies could be used as effective indicators in early diagnosis of esophageal cancer and help to precisely predicate the survival and prognosis.The potential immunotherapeutic targets referring to esophageal cancer are screened and analysed, and the high sensitivity of SOX2 in detecting early esophageal cancer will yield early and effective treatments.

Expression patterns of platinum resistance-related genes in lung adenocarcinoma and related clinical value models

The purpose of this study was to explore platinum resistance-related biomarkers and mechanisms in lung adenocarcinoma. Through the analysis of gene expression data of lung adenocarcinoma patients and normal patients from The Cancer Genome Atlas, Gene Expression Omnibus database, and A database of genes related to platinum resistance, platinum resistance genes in lung adenocarcinoma and platinum resistance-related differentially expressed genes were obtained. After screening by a statistical significance threshold, a total of 252 genes were defined as platinum resistance genes with significant differential expression, of which 161 were up-regulated and 91 were down-regulated. The enrichment results of up-regulated gene Gene Ontology (GO) showed that TOP3 entries related to biological processes (BP) were double-strand break repair, DNA recombination, DNA replication, the down-regulated gene GO enriches the TOP3 items about biological processes (BP) as a response to lipopolysaccharide, muscle cell proliferation, response to molecule of bacterial origin. Gene Set Enrichment Analysis showed that the top three were e2f targets, g2m checkpoint, and rgf beta signaling. A prognostic model based on non-negative matrix factorization classification showed the characteristics of high- and low-risk groups. The prognostic model established by least absolute shrinkage and selection operator regression and risk factor analysis showed that genes such as HOXB7, NT5E, and KRT18 were positively correlated with risk score. By analyzing the differences in m6A regulatory factors between high- and low-risk groups, it was found that FTO, GPM6A, METTL3, and YTHDC2 were higher in the low-risk group, while HNRNPA2B1, HNRNPC, TGF2BP1, IGF2BP2, IGF2BP3, and RBM15B were higher in the high-risk group. Immune infiltration and drug sensitivity analysis also showed the gene characteristics of the platinum-resistant population in lung adenocarcinoma. ceRNA analysis showed that has-miR-374a-5p and RP6-24A23.7 were lower in the tumor expression group, and that the survival of the low expression group was worse than that of the high expression group. In conclusion, the results of this study show that platinum resistance-related differentially expressed genes in lung adenocarcinoma are mainly concentrated in biological processes such as DNA recombination and response to lipopolysaccharide. The validation set proved that the high-risk group of our prognostic model had poor survival. M6A regulatory factor analysis, immune infiltration, and drug sensitivity analysis all showed differences between high and low-risk groups. ceRNA analysis showed that has-miR-374a-5p and RP6-24A23.7 could be protective factors. Further exploration of the potential impact of these genes on the risk and prognosis of drug-resistant patients with lung adenocarcinoma would provide theoretical support for future research.

Protein tyrosine kinase inhibitor resistance in malignant tumors: molecular mechanisms and future perspective

Protein tyrosine kinases (PTKs) are a class of proteins with tyrosine kinase activity that phosphorylate tyrosine residues of critical molecules in signaling pathways. Their basal function is essential for maintaining normal cell growth and differentiation. However, aberrant activation of PTKs caused by various factors can deviate cell function from the expected trajectory to an abnormal growth state, leading to carcinogenesis. Inhibiting the aberrant PTK function could inhibit tumor growth. Therefore, tyrosine kinase inhibitors (TKIs), target-specific inhibitors of PTKs, have been used in treating malignant tumors and play a significant role in targeted therapy of cancer. Currently, drug resistance is the main reason for limiting TKIs efficacy of cancer. The increasing studies indicated that tumor microenvironment, cell death resistance, tumor metabolism, epigenetic modification and abnormal metabolism of TKIs were deeply involved in tumor development and TKI resistance, besides the abnormal activation of PTK-related signaling pathways involved in gene mutations. Accordingly, it is of great significance to study the underlying mechanisms of TKIs resistance and find solutions to reverse TKIs resistance for improving TKIs efficacy of cancer. Herein, we reviewed the drug resistance mechanisms of TKIs and the potential approaches to overcome TKI resistance, aiming to provide a theoretical basis for improving the efficacy of TKIs.

YT521-B homology domain family proteins as N6-methyladenosine readers in tumors

N6-methyladenosine (m6A) is the most abundant internal chemical modification of eukaryotic mRNA and plays diverse roles in gene regulation. The m6A modification plays a significant role in numerous cancer types, including kidney, stomach, lung, bladder tumors, and melanoma, through varied mechanisms. As direct m6A readers, the YT521-B homology domain family proteins (YTHDFs) play a key role in tumor transcription, translation, protein synthesis, tumor stemness, epithelial–mesenchymal transition (EMT), immune escape, and chemotherapy resistance. An in-depth understanding of the molecular mechanism of YTHDFs is expected to provide new strategies for tumor treatment. In this review, we provide a systematic description of YTHDF protein structure and its function in tumor progression.

Research Progress on Long Noncoding RNAs and N6-Methyladenosine in Hepatocellular Carcinoma

N6-methyladenosine (m6A) is an epigenetic modification that widely exists in long noncoding RNAs (lncRNAs) and is involved in the regulation of oncogenes or tumor suppressor genes that form complex enzymes to affect the occurrence of tumors. The abnormal modification of m6A methylation can alter the overall m6A level and thus contribute to the malignant biological behaviors of hepatocellular carcinoma (HCC). LncRNAs related to m6A methylation are involved in lipogenesis, the proliferation, migration and invasion of HCC cells, the stemness of tumor cells and sorafenib resistance. In this review, we systematically elaborated the occurrence mechanism of lncRNA and m6A methylation modification in HCC and the effect of m6A methylation modification of lncRNA on the occurrence of HCC, suggesting that the combination of m6A methylation modification and lncRNA will be more meaningful as molecular markers or prognostic markers. It is helpful to provide further ideas for exploring the pathogenesis of HCC and identifying new targets for HCC treatment and diagnosis and achieve precise individual treatment of liver cancer.

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.

Global research hotspots and trends of the Notch signaling pathway in the field of cancer: a bibliometric study

OBJECTIVES

To analyze the development status, research hotspots, research frontiers and future development trends of the Notch signaling pathway in cancer through bibliometric analysis.

METHODS

Publications related to the Notch signaling pathway in cancer were obtained from the Web of Science Core Collection (WoSCC), and information was extracted from the articles using Microsoft Excel 2020, CiteSpace V and VOSviewer software for visual analysis.

RESULTS

The country and institution with the most publications are the USA and Harvard University, respectively. PLoS One is the most published journal, and Cancer Research is the most cocited journal. The author with the most published articles was L Miele, and the most cocited author was ZW Wang. The top 3 keywords were activation, differentiation and growth. Metastasis, epithelial-mesenchymal transition (EMT), invasion, target and resistance are the current research hotspots and frontiers in this field.

CONCLUSIONS

Research related to the Notch signaling pathway in cancer is currently booming, and the USA has made the greatest contribution to this field. At present, the research hotspots and research frontiers in this field mainly focus on the regulatory role of the Notch signaling pathway in tumor invasion and metastasis, the regulation of the Notch signaling pathway in tumor progression through EMT, and the participation of the Notch signaling pathway in the regulation of chemotherapy or immunotherapy resistance to tumors.

Novel insights into roles of N6-methyladenosine reader YTHDF2 in cancer progression

N6-methyladenosine (m⁶A) is the most abundant RNA modification. M⁶A RNA methylation is reversible: m⁶A is installed by "writers", removed by "erasers", and recognized by "readers". Readers are executors to regulate RNA metabolism by recognizing specific m⁶A sites, including RNA splicing, export, translation and decay. YTHDF2 is the first identified m⁶A reader protein. YTHDF2 interacts with m⁶A-containing transcripts to accelerate the degradation process and regulate various biological processes, such as viral infection, stem cell development and cancer progression. Although there are some reviews about m⁶A modification in physiological and pathological processes, few reviews focus on roles of YTHDF2 in cancers to date. Therefore, in this review, we attempted to systematically summarize m⁶A reader protein YTHDF2: its structure, mechanisms in regulating RNA metabolism, roles in cancer progression and potential application for cancer treatment, which might inspire new ideas for m⁶A research in cancers and provide novel insights into cancer treatment.

Methylation recognition protein YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) regulates the proliferation, migration and invasion of osteosarcoma by regulating m6A level of CCR4-NOT transcription complex subunit 7 (CNOT7)

N6-methyladenosine (m6A) is one of the most significant modifications in human mRNAs. Emerging evidence indicates that m6A participates in the initiation and development of malignant tumors. Nevertheless, the biological roles and mechanism of m6A in osteosarcoma (OS) remain unclear. The purpose of this study was to investigate the role and mechanism of the methylation recognition protein-YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) in OS. The YTHDF1 expression in OS was detected by qRT-PCR and Western blot assay. M6A quantification was utilized to measure the methylation level of OS. Cell counting kit-8 (CCK8), 5-Ethynyl-2’-deoxyuridine (EdU) assay and transwell experiments were conducted to confirm the biological effects of YTHDF1 on OS cells. The bioinformatics websites and in vitro assays were conducted to analyze the downstream targets of YTHDF1 was upregulated in OS tissues at mRNA and protein level. The results showed that the expression level of YTHDF1 might be closely associated with the poor prognosis for OS patients. Inhibition of YTHDF1 could suppress the proliferation, migration and invasion of the OS cells. Moreover, we found that CCR4-NOT transcription complex subunit 7 (CNOT7) might be the potential target of YTHDF1, which was upregulated in OS tissues. YTHDF1 could recognize the m6A sites of CONT7 and promote its expression in an m6A manner. Moreover, methyltransferase-like 3 (METTL3) could promote the m6A level of CONT7. YTHDF1 was upregulated in OS and could promote cell proliferation, migration and invasion. The METTL3-CONT7-YTHDF1 regulatory axis might be the potential target for the prognosis and therapy of OS.