m6A modification of RNA and its role in cancer, with a special focus on lung cancer

RNA modifications in pulmonary diseases

Threatening public health, pulmonary disease (PD) encompasses diverse lung injuries like chronic obstructive PD, pulmonary fibrosis, asthma, pulmonary infections due to pathogen invasion, and fatal lung cancer. The crucial involvement of RNA epigenetic modifications in PD pathogenesis is underscored by robust evidence. These modifications not only shape cell fates but also finely modulate the expression of genes linked to disease progression, suggesting their utility as biomarkers and targets for therapeutic strategies. The critical RNA modifications implicated in PDs are summarized in this review, including N6-methylation of adenosine, N1-methylation of adenosine, 5-methylcytosine, pseudouridine (5-ribosyl uracil), 7-methylguanosine, and adenosine to inosine editing, along with relevant regulatory mechanisms. By shedding light on the pathology of PDs, these summaries could spur the identification of new biomarkers and therapeutic strategies, ultimately paving the way for early PD diagnosis and treatment innovation.

Transcriptome-wide N6-methyladenosine (m6A) methylation profiling of long non-coding RNAs in ovarian endometriosis

N6-methyladenosine (m6A) methylation is the most prevalent internal epigenetic posttranscriptional mechanism for regulating mammalian RNA. Despite recent advances in determining the biological functions of m6A methylation, its association with the pathology of ovarian endometriosis remains uncertain. Herein, we performed m6A transcriptome-wide profiling to identify key lncRNAs with m6A modification involved in ovarian endometriosis development by bioinformatics analysis. We found the total m6A level was lower in ovarian endometriosis than in normal endometrium samples, with 9663 m6A peaks associated with 8989 lncRNAs detected in ovarian endometriosis and 9902 m6A peaks associated with 9210 lncRNAs detected in normal endometrium samples. These m6A peaks were primarily enriched within AAACU motifs. Functional enrichment analysis indicated that pathways involving the regulation of adhesion and development were significantly enriched in these differentially methylated lncRNAs. The regulatory relationships among lncRNAs, microRNAs (miRNAs), and mRNAs were identified by competing endogenous RNA (ceRNA) analysis and determination of the network regulating lncRNA-mRNA expression. Several specific lncRNA, including LINC00665, LINC00937, FZD10-AS1, DIO3OS and GATA2-AS1 which were differently expressed and modified by m6A, were validated using qRT-PCR and its interaction with infiltrating immune cells was explored. Furthermore, we found LncRNA DIO3OS promotes the invasion and migration of Human endometrial stromal cells (THESCs) and ALKBH5 regulates the expression of the lncRNA DIO3OS through m6A modification in vitro. Our study firstly revealed the transcriptome-wide map of m6A modification in lncRNAs of ovarian endometriosis. These findings may enable the determination of the underlying mechanism governing the pathogenesis of ovarian endometriosis and provide theoretical basis for further deeper research on the role of m6A in the development of ovarian endometriosis.

Up-regulation of RNA m6A methyltransferase like-3 expression contributes to arsenic and benzo[a]pyrene co-exposure-induced cancer stem cell-like property and tumorigenesis

While arsenic or BaP alone exposure can cause lung cancer, studies showed that arsenic plus BaP co-exposure displays a significantly stronger lung tumorigenic effect. However, the underlying mechanism has not been well understood. Studies showed that RNA molecules are chemically modified. The most frequently occurring RNA modification in eukaryotic messenger RNAs is the N6-methyladenosine (m6A) methylation. This study aimed to determine whether arsenic plus BaP exposure alters RNA m6A methylation and its role in lung tumorigenic effect of arsenic plus BaP exposure. Human bronchial epithelial cells transformed by exposure to arsenic or BaP alone, and arsenic plus BaP and mouse xenograft tumorigenesis models were used in this study. It was found that arsenic plus BaP exposure-transformed cells have significantly higher levels of RNA m6A methylation than arsenic or BaP alone exposure-transformed human bronchial epithelial cells. Western blot analysis showed that arsenic plus BaP exposure greatly up-regulates the m6A writer methyltransferase like-3 (METTL3) expression levels in cultured cells and mouse lung tissues. METTL3 knockdown in cells transformed by arsenic plus BaP exposure drastically reduced their RNA m6A methylation levels. Functional studies revealed that METTL3 knockdown in cells transformed by arsenic plus BaP exposure greatly reduces their anchorage-dependent and -independent growth, cancer stem cell characters and tumorigenesis. The findings from this study suggest that arsenic plus BaP co-exposure causes epitranscriptomic dysregulation, which may contribute significantly to arsenic plus BaP co-exposure-caused synergistic lung tumorigenic effect.

Role of m6A modification in regulating the PI3K/AKT signaling pathway in cancer

The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays a crucial role in the pathogenesis of cancer. The dysregulation of this pathway has been linked to the development and initiation of various types of cancer. Recently, epigenetic modifications, particularly N6-methyladenosine (m6A), have been recognized as essential contributors to mRNA-related biological processes and translation. The abnormal expression of m6A modification enzymes has been associated with oncogenesis, tumor progression, and drug resistance. Here, we review the role of m6A modification in regulating the PI3K/AKT pathway in cancer and its implications in the development of novel strategies for cancer treatment.

Changes in m6A RNA methylation of goat lung following PPRV infection

Peste des petits ruminants (PPR) is an acute, highly contagious viral disease of goats and sheep, caused by the Peste des petits ruminants virus (PPRV). Earlier studies suggest the involvement of diverse regulatory mechanisms in PPRV infection. Methylation at N6 of Adenosine called m6A is a type RNA modification that influences various physiological and pathological phenomena. As the lung tissue represents the primary target organ of PPRV, the present study explored the m6A changes and their functional significance in PPRV disease pathogenesis. m6A-seq analysis revealed 1289 m6A peaks to be significantly altered in PPRV infected lung in comparison to normal lung, out of which 975 m6A peaks were hypomethylated and 314 peaks were hypermethylated. Importantly, hypomethylated genes were enriched in Interleukin-4 and Interleukin-13 signaling and various processes associated with extracellular matrix organization. Further, of the 843 differentially m6A-containing cellular transcripts, 282 transcripts were also found to be differentially expressed. Functional analysis revealed that these 282 transcripts are significantly enriched in signaling by Interleukins, extracellular matrix organization, cytokine signaling in the immune system, signaling by receptor tyrosine kinases, and Toll-like Receptor Cascades. We also found m6A reader HNRNPC and the core component of methyltransferase complex METTL14 to be highly upregulated than the m6A readers - HNRNPA2B1 and YTHDF1 at the transcriptome level. These findings suggest that alteration in the m6A landscape following PPRV is implicated in diverse processes including Interleukin signaling.

m6A modification and its role in neural development and neurological diseases

N6-methyladenosine (m6A) methylation, the most prevalent post-transcriptional modification in eukaryotes, represents a highly dynamic and reversible process that is regulated by m6A methyltransferases, m6A demethylases and RNA-binding proteins during RNA metabolism, which affects RNA function. Notably, m6A modification is significantly enriched in the brain and exerts regulatory roles in neurogenesis and neurodevelopment through various mechanisms, further influencing the occurrence and progression of neurological disorders. This study systematically summarizes and discusses the latest findings on common m6A regulators, examining their expression, function and mechanisms in neurodevelopment and neurological diseases. Additionally, we explore the potential of m6A modification in diagnosing and treating neurological disorders, aiming to provide new insights into the molecular mechanisms and potential therapeutic strategies for neurological disorders.

RNA m5C methylation orchestrates BLCA progression via macrophage reprogramming

Recently, epigenetics showed essential roles in tumour microenvironment (TME) and immunotherapy response, however, the functions of RNA 5-methylcytosine (m5C) modification in TME remains unknown. According to 13 m5C regulators, we evaluated 412 BLCA patients from The Cancer Genome Atlas (TCGA) database. The m5C score was constructed by unsupervised clustering analysis and principal component analysis (PCA) algorithms. Gene set variation analysis (GSVA), ESTIMATE algorithm, and immunohistochemical (IHC) staining were performed. Macrophage chemotaxis assay was used to assess the M2 macrophages. Among the 412 patients, the frequency of mutation was 13%. m5C regulators was expressed significantly in BLCA tissue compared with normal tissue. Then, two m5C methylation modification patterns were identified with dissimilar TME cell infiltration patterns. The C1 alteration pattern in the m5C cluster was connected with better survival. In addition, we found that NSUN6 was highly correlated with recruitment of macrophages via bioinformatics and IHC. Further experiment validated that NSUN6 promoted HDAC10 expression by mediating m5C methylation, inhibited the transcription of macrophage-associated chemokines and thus inhibited the recruitment of M2 macrophages. The m5C score constructed by m5C modification pattern showed that high m5C score group had a better prognosis. This study uncovered the significant roles of m5C modifications in modulating the TME and indicated that NSUN6 could inhibit the recruitment of M2 macrophages via m5C methylation, which provided novel insight into epigenetic regulation of TME and clinical suggestions for immunotherapeutic strategies.

M6A RNA methylation modification and tumor immune microenvironment in lung adenocarcinoma

Lung adenocarcinoma is one of the deadliest tumors. Studies have shown that N6-methyladenosine RNA methylation regulators, as a dynamic chemical modification, affect the occurrence and development of lung adenocarcinoma. To investigate the relationship between mutations and expression levels of m6A regulators in lung adenocarcinoma, we investigated the mutations and expression levels of 38 m6A regulators. We found that mutations in m6A regulatory factors did not affect the changes in expression levels, and 19 differentially expressed genes were identified. All tumor samples were classified into two subtypes based on the expression levels of 19 differentially expressed m6A-regulated genes. Survival analysis showed significant differences in survival between the two subtypes. To explore the relationship between immune cell infiltration and survival in both subtypes, we calculated the infiltration of 23 immune cells in both subtypes, and we found that the subtype with high immune cell infiltration had better survival. We found that subtypes with low tumor purity and high stromal and immune scores had better survival. The m6A-related immune genes were identified by taking the intersection of differentially expressed genes and immune genes in the two isoforms and calculating the Pearson correlation coefficients between the intersecting immune genes and the differentially expressed m6A-regulated genes. Finally, a prognostic model associated with m6A and associated with immunity was developed using prognostic genes screened from m6A-associated immune genes. The predictive power of the model was evaluated and our model was able to achieve good prediction.

The Regulation of m6A Modification in Glioblastoma: Functional Mechanisms and Therapeutic Approaches

Glioblastoma is the most prevalent primary brain tumour and invariably confers a poor prognosis. The immense intra-tumoral heterogeneity of glioblastoma and its ability to rapidly develop treatment resistance are key barriers to successful therapy. As such, there is an urgent need for the greater understanding of the tumour biology in order to guide the development of novel therapeutics in this field. N6-methyladenosine (m6A) is the most abundant of the RNA modifications in eukaryotes. Studies have demonstrated that the regulation of this RNA modification is altered in glioblastoma and may serve to regulate diverse mechanisms including glioma stem-cell self-renewal, tumorigenesis, invasion and treatment evasion. However, the precise mechanisms by which m6A modifications exert their functional effects are poorly understood. This review summarises the evidence for the disordered regulation of m6A in glioblastoma and discusses the downstream functional effects of m6A modification on RNA fate. The wide-ranging biological consequences of m6A modification raises the hope that novel cancer therapies can be targeted against this mechanism.

Comprehensive analyses of molecular features, prognostic values, and regulatory functionalities of m6A-modified long non-coding RNAs in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) has a high incidence and recurrence rate. N6-methyladenosine (m⁶A) modification of RNA has become a promising epigenetic marker in tumors. The dysregulation of both RNA m⁶A levels and m⁶A regulator expression levels reportedly affects essential biological processes in various tumors. Long non-coding RNAs (lncRNAs), a subgroup of RNAs over 200 nucleotides in length that do not code for protein, can be modified and regulated by m⁶A, but the relevant profile in LUAD remains unclear.

RESULTS

The m⁶A levels of total RNA were decreased in LUAD tumor tissues and cells. Multiple m⁶A regulators were abnormally expressed at both the RNA and protein levels, and were related in expression patterns and functionally synergistic. Our microarray revealed 2846 m⁶A-modified lncRNA transcripts as well as its molecular features, 143 of which were differentially m⁶A-modified and manifested a negative correlation between expression levels and m⁶A modification levels. More than half of the differentially m⁶A-modified lncRNAs associated with dysregulated expression. The 6-MRlncRNA risk signature was a reliable indicator for assessing survival time of LUAD patients. The competitive endogenous regulatory network suggested a potential m⁶A-induced pathogenicity in LUAD.

CONCLUSIONS

These data have demonstrated that differential RNA m⁶A modification and m⁶A regulator expression levels were identified in LUAD patients. In addition, this study provides evidence increasing the understanding of molecular features, prognostic values, and regulatory functionalities of m⁶A-modified lncRNAs in LUAD.

Transcriptome-Wide Study Revealed That N6-Methyladenosine Participates in Regulation Meat Production in Goats

In mammals, skeletal muscle development is a complex biological process regulated by many factors. N6-methyladenosine (m6A) RNA modification plays an important role in many biological processes. However, the regulation of m6A on skeletal muscle growth and development in adult goats remains unclear. In this study, Duan goats (DA) and Nubia goats (NBY), both female and 12 months old, were selected as the research objects, and m6A-Seq and RNA-Seq were mainly used to detect the difference of m6A modification and gene expression during the development of the longissimus dorsi (LD) muscle in the two breeds. The results showed that compared with DA, the meat production performance of NBY was better than that of DA, and the modification level of m6A was higher than that of DA in LD. The m6A-Seq of LD indicated m6A peaks were mainly enriched in the coding sequence (CDS) and stop codon. A total of 161 differentially methylated genes (DMGs) and 1294 differentially expressed genes (DEGs) were identified in two breeds. GO and KEGG analysis showed that DMGs were closely related to cellular metabolism, and most of DMGs were enriched in pathways related to energy metabolism, muscle growth and development, mainly MAPK signaling pathway, Wnt signaling pathway and CGMP-PKG signaling pathway. The DEGs were significantly enriched in actin binding, calcium ion binding, angiogenesis, and other biological processes, and most of them were enriched in PI3K-Akt and CGMP-PKG signaling pathways. Combined analysis of m6A-Seq and RNA-Seq data revealed a negative correlation between differentially methylated m6A levels and mRNA abundance, and mRNA expression of the gene with m6A peak near 3′UTR will decrease. In addition, 11 DMGs regulating cell differentiation, muscle growth and development were identified. This study displayed the m6A profiles and distribution patterns in the goat transcriptome, determined the potential role of m6A modification in muscle growth and provided a new reference for the further study of goat skeletal muscle development.

Roles and therapeutic implications of m6A modification in cancer immunotherapy

Recent studies have demonstrated that N6-methyladenosine (m6A), the most abundant, dynamic, and reversible epigenetic RNA modification in eukaryotes, is regulated by a series of enzymes, including methyltransferases (writers), demethylases (erasers), and m6A recognition proteins (readers). Aberrant regulation of m6A modification is pivotal for tumorigenesis, progression, invasion, metastasis, and apoptosis of malignant tumors. Immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, as recognized by the 2018 Nobel Prize in Medicine and Physiology. However, not all cancer patients response to ICI therapy, which is thought to be the result of intricate immune escape mechanisms. Recently, numerous studies have suggested a novel role for m6A epigenetic modification in the regulation of tumor immune evasion. Herein, we review the relevant mechanisms of m6A regulators in regulating various key signaling pathways in cancer biology and how m6A epigenetic modifications regulate the expression of immune checkpoints, opening a new window to understand the roles and mechanisms of m6A epigenetic modifications in regulating tumor immune evasion. In addition, we highlight the prospects and development directions of future combined immunotherapy strategies based on m6A modification targeting, providing directions for promoting the treatment outcomes of immune checkpoint inhibitors.

RNA Epigenetics in Chronic Lung Diseases

Chronic lung diseases are highly prevalent worldwide and cause significant mortality. Lung cancer is the end stage of many chronic lung diseases. RNA epigenetics can dynamically modulate gene expression and decide cell fate. Recently, studies have confirmed that RNA epigenetics plays a crucial role in the developing of chronic lung diseases. Further exploration of the underlying mechanisms of RNA epigenetics in chronic lung diseases, including lung cancer, may lead to a better understanding of the diseases and promote the development of new biomarkers and therapeutic strategies. This article reviews basic information on RNA modifications, including N⁶ methylation of adenosine (m⁶A), N¹ methylation of adenosine (m¹A), N⁷-methylguanosine (m⁷G), 5-methylcytosine (m⁵C), 2'O-methylation (2'-O-Me or Nm), pseudouridine (5-ribosyl uracil or Ψ), and adenosine to inosine RNA editing (A-to-I editing). We then show how they relate to different types of lung disease. This paper hopes to summarize the mechanisms of RNA modification in chronic lung disease and finds a new way to develop early diagnosis and treatment of chronic lung disease.

Mutual regulation between N6-methyladenosine (m6A) modification and circular RNAs in cancer: impacts on therapeutic resistance

The resistance of tumor cells to therapy severely impairs the efficacy of treatment, leading to recurrence and metastasis of various cancers. Clarifying the underlying mechanisms of therapeutic resistance may provide new strategies for overcoming cancer resistance. N6-methyladenosine (m6A) is the most prevalent RNA modification in eukaryotes, and is involved in the regulation of RNA splicing, translation, transport, degradation, stability and processing, thus affecting several physiological processes and cancer progression. As a novel type of multifunctional non-coding RNAs (ncRNAs), circular RNAs (circRNAs) have been demonstrated to play vital roles in anticancer therapy. Currently, accumulating studies have revealed the mutual regulation of m6A modification and circRNAs, and their interaction can further influence the sensitivity of cancer treatment. In this review, we mainly summarized the recent advances of m6A modification and circRNAs in the modulation of cancer therapeutic resistance, as well as their interplay and potential mechanisms, providing promising insights and future directions in reversal of therapeutic resistance in cancer.

Comprehensive Analysis of the Transcriptome-wide m6A Methylome in Lung Adenocarcinoma by MeRIP Sequencing

N6-methyladenosine (m6A) is the most abundant internal modification on eukaryotic mRNAs. There is increasing evidence that m6A plays a key role in tumor progression, so it is important to analyze m6A modifications within the transcriptome-wide in lung adenocarcinoma (LUAD). Three pairs of LUAD samples and tumor-adjacent normal tissues were obtained from the South University of Science and Technology Hospital. And then methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq) were used to identify differential m6A modifications between tumor and tumor-adjacent normal tissues. We identified 4041 aberrant m6A peaks, of which 1192 m6A peaks were upregulated and 2849 m6A peaks downregulated. It was found that genes with the dysregulated m6A peaks were enriched in the pathways in cancer, Rap1 signaling pathway, and insulin resistance. Additionally, 612 genes with abnormal regulation of m6A peaks and RNA expression were identified by combining MeRIP-seq and RNA-seq data. Through KEGG analysis, the 612 genes were enriched in cancer-related signaling pathways, such as the cGMP-PKG signaling pathway, and the Rap1 signaling pathway. What’s more, GSEA enrichment analysis showed these genes were enriched in cell cycle phase transition, cell division, cellular response to DNA damage stimulus, and chromosome organization. To further explore the relationship between differential m6A modified genes and clinical parameters of LUAD patients, we searched The Cancer Genome Atlas (TCGA) and identified 2 genes (FCRL5 and GPRIN1) that were associated with the prognosis and diagnosis of LUAD patients. Furthermore, we found a positive correlation between GPRIN1 and m6A reader YTHDF1 in the GEPIA2 database. It was verified that YTHDF1 binds to GPRIN1 mRNA and regulates its expression. Our study results suggest that m6A modification plays important role in the progression and prognosis of LUAD and maybe a potential new therapeutic target for LUAD patients in the future.

Construction and validation of a nomogram based on N6-Methylandenosine-related lncRNAs for predicting the prognosis of non-small cell lung cancer patients

BACKGROUND

The N6-methyladenosine (m⁶ A) can modify long non-coding RNAs (lncRNAs), thereby influencing a wide array of biological functions. However, the prognosis of m⁶ A-related lncRNAs (m⁶ ARLncRNAs) in non-small cell lung cancer (NSCLC) remains largely unknown.

METHODS

Pearson correlation analysis was used to identify m⁶ ARLncRNAs in 1835 NSCLC patients and with the condition (|Pearson R| > 0.4 and p < 0.001). Univariant Cox regression analysis was conducted to explore the prognostic m⁶ ARLncRNAs. We filtered prognostic m⁶ ARLncRNAs by LASSO regression and multivariate Cox proportional hazard regression to construct and validate an m⁶ ARLncRNAs signature (m⁶ ARLncSig). We analyzed the correlation between the m⁶ ARLncSig score and clinical features, immune microenvironment, tumor mutation burden, and therapeutic sensitivity and conducted independence and clinical stratification analysis. Finally, we established and validated a nomogram for prognosis prediction in NSCLC patients.

RESULTS

Forty-one m⁶ ARLncRNAs were identified as prognostic lncRNAs, and 12 m⁶ ARLncRNAs were selected to construct m⁶ ARLncSig in the TCGA training dataset. The m⁶ ARLncSig was further validated in the testing dataset, GSE31210, GSE37745, GSE30219, and our NSCLC samples. In terms of m⁶ ARLncSig, NSCLC patients were divided into high- and low-risk groups, with significantly different overall survival (OS), clinical features (age, sex, and tumor stage), tumor-infiltrating immune cells, chemotherapeutic sensitivity, radiotherapeutic response, and biological pathways. Moreover, m⁶ ARLncSig independently predicted the OS of NSCLC patients. Finally, the robustness and clinical practicability for predicting NSCLC patient prognosis was improved by constructing a nomogram containing the m⁶ ARLncSig, age, gender, and tumor stage.

CONCLUSIONS

Our study demonstrated that m⁶ ARLncSig could act as a potential biomarker for evaluating the prognosis and therapeutic efficacy in NSCLC patients.

Construction of m6A-Related lncRNA Prognostic Signature Model and Immunomodulatory Effect in Glioblastoma Multiforme

Background

Glioblastoma multiforme (GBM), the most prevalent and aggressive of primary malignant central nervous system tumors (grade IV), has a poor clinical prognosis. This study aimed to assess and predict the survival of GBM patients by establishing an m6A-related lncRNA signaling model and to validate its validity, accuracy and applicability.

Methods

RNA sequencing data and clinical data of GBM patients were obtained from TCGA data. First, m6A-associated lncRNAs were screened and lncRNAs associated with overall survival in GBM patients were obtained. Subsequently, the signal model was established using LASSO regression analysis, and its accuracy and validity are further verified. Finally, GO enrichment analysis was performed, and the influence of this signature on the immune regulation response and anticancer drug sensitivity of GBM patients was discussed.

Results

The signature constructed by four lncRNAs AC005229.3, SOX21-AS1, AL133523.1, and AC004847.1 is obtained. Furthermore, the signature proved to be effective and accurate in predicting and assessing the survival of GBM patients and could function independently of other clinical characteristics (Age, Gender and IDH1 mutation). Finally, Immunosuppression-related factors, including APC co-inhibition, T-cell co-inhibition, CCR and Check-point, were found to be significantly up-regulated in GBM patients in the high-risk group. Some chemotherapeutic drugs (Doxorubicin and Methotrexate) and targeted drugs (AZD8055, BI.2536, GW843682X and Vorinostat) were shown to have higher IC50 values in patients in the high-risk group.

Conclusion

We constructed an m6A-associated lncRNA risk model to predict the prognosis of GBM patients and provide new ideas for the treatment of GBM. Further biological experiments can be conducted on this basis to validate the clinical value of the model.

LINC01021 maintains tumorigenicity by enhancing N6-methyladenosine reader IMP2 dependent stabilization of MSX1 and JARID2: implication in colorectal cancer

Insulin-like growth factor-2 mRNA-binding protein 2 (IGF2BP2, also known as IMP2), a novel class III N6-methyladenosine (m⁶A) reader, has recently gained attention due to its critical functions in recognizing and stabilizing m⁶A modified oncogenic transcripts. However, whether and how long non-coding RNAs (lncRNAs) facilitate IMP2's role as m⁶A "reader" remains elusive, particularly in colorectal cancer (CRC). Here, we demonstrated that oncogenic LINC021 specifically bound with the m⁶A "reader" IMP2 protein and enhanced the mRNA stability of MSX1 and JARID2 in an m⁶A regulatory manner during CRC tumorigenesis and pathogenesis. Specifically, a remarkable upregulation of LINC021 was confirmed in CRC cell lines and clinical tissues (n = 130). High level of LINC021acted as an independent prognostic predictor for CRC clinical outcomes. Functional assays demonstrated that LINC021 exerted its functions as an oncogene to aggravate CRC malignant phenotypes including enhanced cell proliferation, colony formation, migration capabilities, and reduced cell apoptosis. Mechanistically, LINC021 directly recognized IMP2 protein, the latter enhanced the mRNA stability of transcripts such as MSX1 and JARID2 by recognizing their m⁶A-modified element RGGAC. Thus, these findings uncovered an essential LINC021/IMP2/MSX1 and JARID2 signaling axis in CRC tumorigenesis, which provided profound insights into our understanding of m⁶A modification regulated by lncRNA in CRC initiation and progression and shed light on the targeting of this axis for CRC treatment.

Identification and Validation of the Pyroptosis-Related Molecular Subtypes of Lung Adenocarcinoma by Bioinformatics and Machine Learning

Lung cancer remains the leading cause of cancer death globally, with lung adenocarcinoma (LUAD) being its most prevalent subtype. Due to the heterogeneity of LUAD, patients given the same treatment regimen may have different responses and clinical outcomes. Therefore, identifying new subtypes of LUAD is important for predicting prognosis and providing personalized treatment for patients. Pyroptosis-related genes play an essential role in anticancer, but there is limited research investigating pyroptosis in LUAD. In this study, 33 pyroptosis gene expression profiles and clinical information were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. By bioinformatics and machine learning analyses, we identified novel subtypes of LUAD based on 10 pyroptosis-related genes and further validated them in the GEO dataset, with machine learning models performing up to an AUC of 1 for classifying in GEO. A web-based tool was established for clinicians to use our clustering model (http://www.aimedicallab.com/tool/aiml-subphe-luad.html). LUAD patients were clustered into 3 subtypes (A, B, and C), and survival analysis showed that B had the best survival outcome and C had the worst survival outcome. The relationships between pyroptosis gene expression and clinical characteristics were further analyzed in the three molecular subtypes. Immune profiling revealed significant differences in immune cell infiltration among the three molecular subtypes. GO enrichment and KEGG pathway analyses were performed based on the differential genes of the three subtypes, indicating that differentially expressed genes (DEGs) were involved in multiple cellular and biological functions, including RNA catabolic process, mRNA catabolic process, and pathways of neurodegeneration-multiple diseases. Finally, we developed an 8-gene prognostic model that accurately predicted 1-, 3-, and 5-year overall survival. In conclusion, pyroptosis-related genes may play a critical role in LUAD, and provide new insights into the underlying mechanisms of LUAD.