TTC22 promotes m6A-mediated WTAP expression and colon cancer metastasis in an RPL4 binding-dependent pattern

CALB2 facilitates macrophage M2 polarization to promote the growth and metastasis of pancreatic adenocarcinoma

Tumor-associated macrophages mainly differentiate into M2 phenotypes, which secrete cytokines that reshape the tumor microenvironment and promote tumor progression. This study was to explore the mechanism of CALB2 in M2 polarization and pancreatic adenocarcinoma (PAAD). Clinical tissue samples of PAAD were collected, followed by detection of WTAP, FOSL1, and CALB2 expression. The correlation between WTAP and FOSL1 or between FOSL1 and CALB2 was analyzed. THP1 cells were induced into M0 macrophages, followed by plasmid transfection and induction of M2-type macrophages. After macrophages were co-cultured with PAAD cells, functional experiments were designed to evaluate PAAD cell malignant behaviors. A transplantation tumor model and a liver metastasis model were established to assess tumor growth and metastasis. High expression of WTAP, FOSL1, and CALB2 was found in PAAD tissues and M2-type macrophages. WTAP positively linked with FOSL1, so as FOSL1 and CALB2. Mechanistically, WTAP enhanced m6A modification of FOSL1 to promote its expression, and FOSL1 promoted CALB2 transcription. Knockdown of WTAP, FOSL1, or CALB2 in macrophages inhibited PAAD cell malignant behaviors, which could be reversed by CALB2 upregulation. WTAP knockdown restrained the growth and metastasis of PAAD in nude mice via the FOSL1/CALB2 axis. In conclusion, WTAP increased the m6A level of FOSL1, activated CALB2 transcription, and promoted M2 polarization of macrophages, thereby promoting the growth and metastasis of PAAD.

WTAP/IGF2BP3 Mediated m6A Modification of SOD2 mRNA Aggravates the Tumourigenesis of Colorectal Cancer

Wilms tumor 1-associated protein (WTAP) has been validated to be a crucial regulator in the tumorigenesis and advancement of diverse malignancies. This study intended to probe the impacts of WTAP on colorectal cancer (CRC) progression from the perspective of N6-methyladenosine (m6A) modification. The differential expression patterns of WTAP in clinical CRC samples and cultured cell lines were validated via qRT-PCR and western blot. Cell function tests were conducted with colony formation, transwell, and CCK-8. MeRIP-qPCR was conducted to identify the WTAP-mediated SOD2 (Superoxide dismutase 2) mRNA modification in CRC cells. Animal experiments were adopted to evaluate the function of WTAP in vivo. WTAP exhibited high expression pattern in CRC samples along with cells. Silencing of WTAP potently restrained the growth of CRC tumorigenesis in virto and in vivo. Mechanically, SOD2 was identified as an m6A target of WTAP. WTAP-mediated m6A modification of SOD2 mRNA elevated its stability in an IGF2BP3-dependent manner. Meanwhile, SOD2 overexpression could reverse the tumor suppressive effect induced by WTAP silencing. Molecular therapy targeting WTAP-SOD2 may offer novel insights and perspectives for the treatment of CRC.

WTAP Promotes the Excessive Proliferation of Airway Smooth Muscle Cells in Asthma by Enhancing AXIN1 Levels Through the Recognition of YTHDF2

Asthma is a common chronic respiratory disease in children, the incidence rate of which has increased in recent years. Wilms tumour 1-associated protein (WTAP) is an N6-methyladenosine (m6A) methyltransferase. The purpose of this study was to explore the specific mechanism of WTAP in asthma progression, and clarify the intricate interplay between m6A modifications, WTAP, AXIN1, and their collective impact on airway smooth muscle cells (ASMCs) proliferation in asthma. Platelet-derived growth factor-BB (PDGF-BB)-treated ASMCs were used to establish an asthma model in vitro. The cell phenotype was tested using CCK-8, transwell, and wound healing assays. The expression of the Wnt signalling pathway was detected by western blotting. In addition, the relationship between WTAP/YTDHF2 and AXIN1 was assessed by a double luciferase reporter assay. Actinomycin D treatment and RT‒qPCR assays were performed to determine the mRNA stability of AXIN1. We found that WTAP was significantly increased in PDGF-BB-treated ASMCs. Knockdown of WTAP inhibited the excessive cell viability and migration of ASMCs induced by PDGF-BB. Furthermore, WTAP knockdown increased AXIN1 levels and inhibited the Wnt signalling pathway. Furthermore, WTAP knockdown decreased the m6A levels and enhanced the mRNA stability of AXIN1. WTAP overexpression showed the opposite effect. In addition, YTHDF2 was demonstrated to be the reader that recognizes the WTAP-mediated m6A modification of AXIN1. YTHDF2 knockdown enhanced the mRNA stability of AXIN1 and reversed the effect of WTAP overexpression on PDGF-BB-treated ASMCs. WTAP knockdown inhibited the excessive cell viability and migration of ASMCs by enhancing the m6A levels of AXIN1, which was further recognized by YTHDF2. The upregulation of AXIN1 mediated by the WTAP/YTHDF2 axis further inhibited the Wnt signalling pathway. Our study provides a new method for the treatment of asthma. This work not only deepens our understanding of the molecular underpinnings of asthma but also identifies potential therapeutic targets for the development of novel treatments aimed at inhibiting ASMC proliferation and alleviating asthma symptoms.

WTAP promotes the progression of ulcerative colitis by silencing the expression of CES2 through m6A modification

OBJECTIVE

This study will explore the function of WTAP, the critical segment of m6A methyltransferase complex, in UC and its regulation on immune response.

METHODS

The expression levels of key proteins were detected in colon tissues which were derived from UC patients and mice. Macrophage polarization and CD4+ T cell infiltration were detected by flow cytometry and IF staining. ELISA assay was utilized to analyze the level of the inflammatory cytokines. m6A-RIP-PCR, actinomycin D test, and RIP assays were utilized to detect the m6A level, stability, and bound proteins of CES2 mRNA. A dual luciferase reporter assay was conducted to confirm the transcriptional interactions between genes. A co-culture system of intestinal epithelium-like organs was constructed to detect the primary mouse intestinal epithelial cells (PMIEC) differentiation. The interaction between proteins was detected via Co-IP assay.

RESULTS

The expression of WTAP and CES2 in UC tissues was increased and decreased, respectively. Knockdown of WTAP inhibited the progression of UC in mice by inhibiting M1 macrophage polarization and CD4+ T cell infiltration. WTAP combined YTHDF2 to promote the m6A modification of CES2 mRNA and inhibited its expression. CES2 co-expressed with EPHX2 and overexpression of CES2 promoted the differentiation of PMIEC. The inhibitory effect of WTAP knockdown on the progress of UC was partially abrogated by CES2 knockdown.

CONCLUSION

WTAP/YTHDF2 silences CES2 by promoting its m6A modification and then promotes the progression of UC. WTAP could be a promoting therapy target of UC.

Unraveling the molecular complexity: Wtap/Ythdf1 and Lcn2 in novel traumatic brain injury secondary injury mechanisms

The primary aim of this research was to explore the functions of Wtap and Ythdf1 in regulating neuronal Lipocalin-2 (Lcn2) through m6A modification in traumatic brain injury (TBI). By employing transcriptome sequencing and enrichment analysis, we identified the Wtap/Ythdf1-mediated Lcn2 m6A modification pathway as crucial in TBI. In our in vitro experiments using primary cortical neurons, knockout of Wtap and Ythdf1 led to the inhibition of Lcn2 m6A modification, resulting in reduced neuronal death and inflammation. Furthermore, overexpression of Lcn2 in cortical neurons induced the activation of reactive astrocytes and M1-like microglial cells, causing neuronal apoptosis. In vivo experiments confirmed the activation of reactive astrocytes and microglial cells in TBI and importantly demonstrated that Wtap knockdown improved neuroinflammation and functional impairment. These findings underscore the significance of Wtap/Ythdf1-mediated Lcn2 regulation in TBI secondary injury and suggest potential therapeutic implications for combating TBI-induced neuroinflammation and neuronal damage.

RNA methylation: A potential therapeutic target in autoimmune disease

Autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and inflammatory bowel disease (IBD) are caused by the body's immune response to autoantigens. The pathogenesis of autoimmune diseases is unclear. Numerous studies have demonstrated that RNA methylation plays a key role in disease progression, which is essential for post-transcriptional regulation and has gradually become a broad regulatory mechanism that controls gene expression in various physiological processes, including RNA nuclear output, translation, splicing, and noncoding RNA processing. Here, we outline the writers, erasers, and readers of RNA methylation, including N6-methyladenosine (m6A), 2'-O-methylation (Nm), 2'-O-dimethyladenosine (m6Am), N1-methyladenosine (m1A), 5-methylcytidine (m5C) and N7-methylguanosine (m7G). As the role of RNA methylation modifications in the immune system and diseases is explained, the potential treatment value of these modifications has also been demonstrated. This review reports the relationship between RNA methylation and autoimmune diseases, highlighting the need for future research into the therapeutic potential of RNA modifications.

N6-methyladenosine demethyltransferase FTO mediated m6A modification of estrogen receptor alpha in non-small cell lung cancer tumorigenesis

Fat mass and obesity-associated protein (FTO), which is closely linked with obesity and dietary intake, plays an important role in diet-related metabolic diseases. However, the underlying mechanism of the N6-methyladenosine (m6A) demethyltransferase FTO in tumor development and progression remains largely unexplored. Here, we demonstrated that FTO expression was largely lower in non-small cell lung cancer (NSCLC) samples than in adjacent healthy tissues, and its expression negatively correlated with poor prognosis. Gain- and loss-of-function assays revealed that FTO inhibited NSCLC tumor cell growth and metastasis in vitro and in vivo. Mechanistically, estrogen receptor alpha (ESR1) is a target of FTO, and increased FTO expression significantly impaired the m6A levels of ESR1 mRNA. There were two clear m6A modification sites (5247A and 5409A) in the 3' untranslated region (3'UTR) of ESR1, and FTO could decrease their methylation. Moreover, the m6A readers YTHDF1 and IGF2BP3 recognized and bound the m6A sites in ESR1 mRNA, thereby enhancing its stability and facilitating tumor growth. We also showed that ESR1 has good diagnostic value for NSCLC. In conclusion, we uncovered an important mechanism of epitranscriptomic regulation by the FTO-YTHDF1-IGF2BP3-ESR1 axis and identified the potential of m6A-dependent therapeutic strategies for NSCLC.

A pan-cancer analysis of the prognosis and immune infiltration of eEF1A2 and its potential function in thyroid carcinoma

Purpose

Eukaryotic translation elongation factor 1α2 (eEF1A2) promotes tumour progression in various cancers. We performed a pan-cancer analysis of eEF1A2 and explored its role in thyroid carcinoma (THCA).

Methods

Databases from The Cancer Genome Atlas (TCGA), the University of Alabama at Birmingham Cancer data analysis Portal (UALCAN), and the Human Protein Atlas (HPA) were used to investigate the differential expression of eEF1A2 in pan-cancer. The pathological stage, prognostic characteristics, tumour microenvironment (TME), tumour mutational burden (TMB), and microsatellite instability (MSI) were analysed in diverse tumours with different expression levels of eEF1A2. The expression levels in papillary thyroid carcinoma (PTC) and its specific role in cell proliferation, migration, invasion, and cell glycolysis in PTC cells were verified by quantitative real time polymerase chain reaction (qRT-PCR), immunohistochemistry, cell counting kit-8, colony formation, wound healing, Transwell assay, and lactate acid and glucose assays.Results:eEF1A2 was differentially expressed in various malignant tumour tissues compared to control tissues and was associated with poor pathological stage and prognosis in most types of tumours. Moreover, eEF1A2 expression closely correlated with the infiltration of immunosuppressive cells, TMB, and MSI in some tumour types. Expression of eEF1A2 in PTC is higher than the para-carcinoma, and eEF1A2 downregulation suppressed TPC-1 and BCPAP cell proliferation, migration, invasion, and glycolysis.

Conclusion

Our study suggests that the expression of eEF1A2 is related to the prognosis and immune infiltration of some tumours and may be a predictor of prognosis and immunotherapy. eEF1A2 could promote malignant behaviour of PTC cells.

TTC22 as a potential prognostic marker and therapeutic target in pancreatic cancer: Insights into immune infiltration and epithelial‑mesenchymal transition

The mortality rate of pancreatic adenocarcinoma is high, and the effect of traditional treatment is unsatisfactory, thus novel biomarkers are required. Although the important role of tetratricopeptide repeat domain 22 (TTC22) in colon cancer is well established, its precise role in pancreatic cancer remains unclear and requires further investigation. Pan-cancer analysis and single-cell sequencing revealed TTC22 was differentially expressed in various tumors, especially in pancreatic adenocarcinoma. Additionally, clinical data for pancreatic cancer showed a negative association between TTC22 expression and clinical parameters, including survival prognosis. The correlation between TTC22 and immune infiltration in pancreatic cancer was validated by functional enrichment analysis. ESTIMATE and single sample Gene Set Enrichment Analysis algorithms were used to further analyze immune infiltration of TTC22 in pancreatic cancer, and the results suggested that TTC22 inhibited tumor immunity and was negatively correlated with plasmacytoid dendritic cells. Reverse transcription-quantitative PCR further confirmed the differential expression of TTC22 in pancreatic cancer cell lines. Wound healing, Transwell and colony formation assays showed that TTC22 affected the migration and invasion of pancreatic cancer cells. These findings demonstrate that TTC22 may serve as a potential prognostic marker and therapeutic target for the management of pancreatic cancer.

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.

LncRNA miR663AHG represses the development of colon cancer in a miR663a-dependent manner

The MIR663AHG gene encodes both miR663AHG and miR663a. While miR663a contributes to the defense of host cells against inflammation and inhibits colon cancer development, the biological function of lncRNA miR663AHG has not been previously reported. In this study, the subcellular localization of lncRNA miR663AHG was determined by RNA-FISH. miR663AHG and miR663a were measured by qRT-PCR. The effects of miR663AHG on the growth and metastasis of colon cancer cells were investigated in vitro and in vivo. CRISPR/Cas9, RNA pulldown, and other biological assays were used to explore the underlying mechanism of miR663AHG. We found that miR663AHG was mainly distributed in the nucleus of Caco2 and HCT116 cells and the cytoplasm of SW480 cells. The expression level of miR663AHG was positively correlated with the level of miR663a (r = 0.179, P = 0.015) and significantly downregulated in colon cancer tissues relative to paired normal tissues from 119 patients (P < 0.008). Colon cancers with low miR663AHG expression were associated with advanced pTNM stage (P = 0.021), lymph metastasis (P = 0.041), and shorter overall survival (hazard ratio = 2.026; P = 0.021). Experimentally, miR663AHG inhibited colon cancer cell proliferation, migration, and invasion. The growth of xenografts from RKO cells overexpressing miR663AHG was slower than that of xenografts from vector control cells in BALB/c nude mice (P = 0.007). Interestingly, either RNA-interfering or resveratrol-inducing expression changes of miR663AHG or miR663a can trigger negative feedback regulation of transcription of the MIR663AHG gene. Mechanistically, miR663AHG could bind to miR663a and its precursor pre-miR663a, and prevent the degradation of miR663a target mRNAs. Disruption of the negative feedback by knockout of the MIR663AHG promoter, exon-1, and pri-miR663A-coding sequence entirely blocked these effects of miR663AHG, which was restored in cells transfected with miR663a expression vector in rescue experiment. In conclusion, miR663AHG functions as a tumor suppressor that inhibits the development of colon cancer through its cis-binding to miR663a/pre-miR663a. The cross talk between miR663AHG and miR663a expression may play dominant roles in maintaining the functions of miR663AHG in colon cancer development.

The Emerging, Multifaceted Role of WTAP in Cancer and Cancer Therapeutics

Cancer is a grave and persistent illness, with the rates of both its occurrence and death toll increasing at an alarming pace. N6-methyladenosine (m⁶A), the most prevalent mRNA modification in eukaryotic organisms, is catalyzed by methyltransferases and has a significant impact on various aspects of cancer progression. WT1-associated protein (WTAP) is a crucial component of the m⁶A methyltransferase complex, catalyzing m⁶A methylation on RNA. It has been demonstrated to participate in numerous cellular pathophysiological processes, including X chromosome inactivation, cell proliferation, cell cycle regulation, and alternative splicing. A better understanding of the role of WTAP in cancer may render it a reliable factor for early diagnosis and prognosis, as well as a key therapeutic target for cancer treatment. It has been found that WTAP is closely related to tumor cell cycle regulation, metabolic regulation, autophagy, tumor immunity, ferroptosis, epithelial mesenchymal transformation (EMT), and drug resistance. In this review, we will focus on the latest advances in the biological functions of WTAP in cancer, and explore the prospects of its application in clinical diagnosis and therapy.

CMTR1 promotes colorectal cancer cell growth and immune evasion by transcriptionally regulating STAT3

CMTR1, also called IFN-stimulated gene 95 kDa protein (ISG95), is elevated by viral infection in a variety of cells. However, the functions of CMTR1 in colorectal cancer (CRC), especially its roles in tumorigenesis and immune regulation, remain unclear. Here, we first identified CMTR1 as a novel oncogene in colorectal cancer. Based on The Cancer Genome Atlas (TCGA) database exploration and human tissue microarray (TMA) analysis, we found that CMTR1 expression was markedly higher in CRC tissues than in adjacent normal tissues. High CMTR1 expression was correlated with poor prognosis in CRC patients. Knockdown (KD) of CMTR1 significantly suppressed cell proliferation and tumorigenicity both in vitro and in vivo, whereas overexpression of CMTR1 resulted in the opposite effects. KEGG pathway analysis revealed differential enrichment in the JAK/STAT signaling pathway in colorectal cancer cells with CMTR1 KD. Mechanistically, suppression of CMTR1 expression inhibited RNAPII recruitment to the transcription start site (TSS) of STAT3 and suppressed STAT3 expression and activation. Furthermore, the efficacy of PD1 blockade immunotherapy was prominently enhanced in the presence of CMTR1 KD via increased infiltration of CD8 + T cells into the tumor microenvironment. Overall, it appears that CMTR1 plays a key role in regulating tumor cell proliferation and antitumor immunity.