M6A RNA methylation: A key regulator in renal cell carcinoma development and tumor radioresistance

N6-Methyladenosine RNA Methylation Regulators Contribute to Malignant Progression and Survival Prediction in Chronic Lymphocytic Leukemia

Oncologic Outcomes Following Surgical Resection of Renal Cell Carcinoma with Inferior Vena Caval Thrombus Extending Above the Hepatic Veins: A Contemporary Multicenter Cohort

Cytogenetic and molecular genetic techniques have been used in demonstrating the chromosomal abnormalities which characterize specific subtypes of renal cell carcinoma (RCC). The aim of this study was to determine the efficiency of fluorescent in situ hybridization (FISH) technique in characterizing various subtypes of RCC based on the presence of specific chromosome abnormalities found in each RCC subtype. FISH was performed on touch imprint smears from eight renal cell carcinomas histologically confirmed by established criteria. In four tumors with histologic features of chromophobe renal cell carcinoma (ChRCC), interphase FISH was performed using centromeric probes for chromosomes 1, 2, 6, 10, 12, 17 and 21. All four ChRCC tumors showed one FISH signal corresponding to one copy number for each of these chromosomes. Two papillary RCCs included in this study showed trisomy 7 and 17, and loss of chromosome Y, using the corresponding chromosome centromeric probes. Similarly, we tested two clear cell RCCs for chromosome 3 short arm deletion with DNA probe 3p21.3. Both tumors showed loss of 3p21.3 signal. We conclude that interphase FISH performed on touch imprint smears is a relatively simple, rapid and reliable method for detecting chromosome abnormalities which are specific for various subtypes of RCC.

There is a growing scientific view that the improvement of cancer by nonstarch polysaccharides (NSPs) is mediated by intestinal microbiota. Intestinal bacteria affect the supply of methyl donor substances and influence N6-methyladenosine (m6A) RNA methylation. As one of the epigenetic/epitranscriptomic modifications, m6A RNA methylation is closely related to the initiation and progression of cancers. This review summarizes the cancer-improving effects of NSPs through modulation of intestinal microbiota. It also summarizes the relationship between intestinal bacteria and the supply of methyl donor substances. Moreover, it also provides a summary of the effects of m6A RNA methylation on various types of cancer. The proposed mechanism is that, dietary consumed NSPs are utilized by specific intestinal bacteria and further reshape the microbial structure. Methyl donor substances will be directly or indirectly generated by the reshaped-microbiota, and affect the m6A RNA methylation of cancer-related and pro-carcinogenic inflammatory cytokine genes. Therefore, NSPs may change the m6A RNA methylation by affecting the methyl donor supply produced by intestinal microbiota and ameliorate cancer. This review discussed the possibility of cancer improvement of bioactive NSPs achieved by impacting RNA methylation via the intestinal microbiota, and it will offer new insights for the application of NSPs toward specific cancer prevention.

Accumulating evidence has proven that N6-methyladenosine (m6A) RNA methylation plays an essential role in tumorigenesis. However, the significance of m6A RNA methylation modulators in the malignant progression of papillary renal cell carcinoma (PRCC) and their impact on prognosis has not been fully analyzed. The present research set out to explore the roles of 17 m6A RNA methylation regulators in tumor microenvironment (TME) of PRCC and identify the prognostic values of m6A RNA methylation regulators in patients afflicted by PRCC. We investigated the different expression patterns of the m6A RNA methylation regulators between PRCC tumor samples and normal tissues, and systematically explored the association of the expression patterns of these genes with TME cell-infiltrating characteristics. Additionally, we used LASSO regression to construct a risk signature based upon the m6A RNA methylation modulators. Two-gene prognostic risk model including IGF2BP3 and HNRNPC was constructed and could predict overall survival (OS) of PRCC patients from the Cancer Genome Atlas (TCGA) dataset. The prognostic signature-based risk score was identified as an independent prognostic indicator in Cox regression analysis. Moreover, we predicted the three most significant small molecule drugs that potentially inhibit PRCC. Taken together, our study revealed that m6A RNA methylation regulators might play a significant role in the initiation and progression of PRCC. The results might provide novel insight into exploration of m6A RNA modification in PRCC and provide essential guidance for therapeutic strategies.

Colorectal cancer (CRC) ranks among the most common malignant cancers of the digestive system, and its initiation and progression are closely related to both genetic and epigenetic mechanisms. Three major forms of modifications, viz. DNA methylation, RNA m6A methylation, and histone methylation, play important roles in regulating gene expression at various stages of transcription and translation. These methylation processes are dynamic and reversible, relying on the functions of methyltransferases, demethylases, and methylation-binding proteins. Extensive studies have shown that DNA, RNA m6A, and histone methylation significantly impact multiple pathological and physiological processes in CRC, including carcinogenesis, recurrence, metastasis, resistance to both radiotherapy and chemotherapy, as well as immune regulation. Advances in high-throughput sequencing and laboratory techniques have facilitated the identification of methylation regulation enzymes with aberrant expression at the DNA, RNA, and protein levels, revealing their clinical potential for early diagnosis and treatment of CRC. The upstream regulatory mechanisms controlling these methylation regulation enzymes are crucial for understanding alterations in methylation patterns. Current evidence identifies several key mechanisms, including posttranslational modifications, epigenetic regulation, and genetic alterations, which collectively influence the expression, activity, and stability of methyltransferases, demethylases, and binding proteins. These mechanisms thereby modulate the dynamic methylation landscape across various biological contexts. Furthermore, the complex crosstalk among DNA, RNA m6A, and histone methylation is increasingly being elucidated, highlighting a need for further investigation in CRC. In this review, we systematically summarize the molecular mechanisms, clinical applications, and crosstalk involving DNA methylation, RNA m6A methylation, and histone methylation, along with their related enzymes in the development of CRC. This review aims to provide new insights and directions that underscore the significant role of epigenetic methylation modifications and their associated enzymes in CRC.

Pax 2, expressed by metanephric mesenchyme is vital for renal tubule formation and development. Carbonic anhydrase IX (CA IX) is implicated in cell proliferation, adhesion, and invasion. Data regarding expression in renal epithelial tumors other than clear cell renal cell carcinoma (RCC) are limited, conflicting, from tissue microarrays, and do not encompass the entire spectrum or novel uncommon variants. Conventional sections from 200 renal tumors comprising clear cell RCC (n=30), oncocytoma (n=17), papillary RCC (n=30), chromophobe RCC (n=50), urothelial carcinomas (n=30), collecting duct carcinomas (n=5), renal tumors with Xp11.2 translocation (n=15), tubulocystic carcinoma (n=19), and mucinous tubular spindle cell carcinoma (n=4) were immunostained for Pax 2 and CA IX. Clear cell RCC (28/30, 93%), oncocytoma (17/17, 100%), papillary RCC (16/30, 53%), and mucinous tubular spindle cell carcinoma (3/4, 75%) demonstrated nuclear immunoreactivity with Pax 2, whereas the other subtypes were nonreactive. Clear cell RCC (30/30, 100%), urothelial carcinoma (27/30, 90%), papillary RCC (17/30, 57%), and renal tumors with Xp11.2 translocation (6/15, 40%) exhibited membranous immunoreactivity with CA IX, whereas the other subtypes were nonreactive. This suggests potential diagnostic utility of Pax 2 in distinction of (i) oncocytoma (positive) from chromophobe RCC (negative), (ii) clear cell RCC and papillary RCC (positive) from renal tumors with Xp11.2 translocation (negative), and (iii) high-grade clear cell RCC (positive) from urothelial carcinoma (negative). CA IX expression has potential diagnostic implications including (i) clear cell RCC (positive) versus chromophobe RCC (negative) and (ii) urothelial carcinoma (positive) versus collecting duct carcinoma (negative). These antibodies may reliably discriminate between clinically significant subtypes of RCC with overlapping cytoarchitectural features.

The authors report the case of a 42-year-old man with a rare coexistence of clear cell renal cell carcinoma and gastrointestinal stromal tumor of the stomach with concurrent portal vein metastasis. After surgical resection of the two original masses, the patient was treated with sunitinib malate to control the portal vein metastasis. The metastatic lesion completely disappeared after two cycles of treatment. This is the first known reported case of synchronous clear cell renal cell carcinoma and gastrointestinal stromal tumor with distal metastasis, and the first report of the favorable efficacy and safety of sunitinib in treating this rare synchronous dual malignancy.

Fusaric acid (FA) is a food-borne mycotoxin that mediates toxicity with limited information on its epigenetic properties. p53 is a tumour suppressor protein that regulates cell cycle arrest and apoptotic cell death. The expression of p53 is regulated transcriptionally by promoter methylation and post-transcriptionally by N-6-methyladenosine (m6A) RNA methylation. We investigated the effect of FA on p53 expression and its epigenetic regulation via promoter methylation and m6A RNA methylation in human hepatocellular carcinoma (HepG2) cells. HepG2 cells were treated with FA [0, 25, 50, 104, and 150 µg/ml; 24 h] and thereafter, DNA, RNA, and protein was isolated. Promoter methylation and expression of p53 was measured using qPCR and Western blot. RNA immuno-precipitation was used to determine m6A-p53 levels. The expression of m6A methyltransferases (METTL3 and METTL14), demethylases (FTO and ALKBH5), and readers (YTHDF1-3 and YTHDC2) were measured using qPCR. FA induced p53 promoter hypermethylation (p < 0.0001) and decreased p53 expression (p < 0.0001). FA decreased m6A-p53 levels (p < 0.0001) by decreasing METTL3 (p < 0.0001) and METTL14 (p < 0.0001); and suppressed expression of YTHDF1 (p < 0.0001), YTHDF3 (p < 0.0001), and YTHDC2 (p < 0.0001) that ultimately reduced p53 translation (p < 0.0001). Taken together, the data shows that FA epigenetically decreased p53 expression by altering its promoter methylation and m6A RNA methylation in HepG2 cells. This study reveals a mechanism for p53 regulation by FA and provides insight into future therapeutic interventions.

Ginsenoside Rh2 reduces m6A RNA methylation in cancer via the KIF26B-SRF positive feedback loop

Fto Promotes Extramedullary Progression of Multiple Myeloma By Regulation of HSF1 through m6a RNA Methylation

Renal Cell Carcinoma with Thrombus Extension into the Inferior Vena Cava and the Right Atrium: A Case Report

BackgroundMethionine or lysine has been reported to influence DNA methylation and fat metabolism, but their combined effects in N6-methyl-adenosine (m6A) RNA methylation remain unclarified. The combined effects of rumen-protected methionine and lysine (RML) in a low-protein (LP) diet on lipid metabolism, m6A RNA methylation, and fatty acid (FA) profiles in the liver and muscle of lambs were investigated. Sixty-three male lambs were divided into three treatment groups, three pens per group and seven lambs per pen. The lambs were fed a 14.5% crude protein (CP) diet (adequate protein [NP]), 12.5% CP diet (LP), and a LP diet plus RML (LP + RML) for 60 d.ResultsThe results showed that the addition of RML in a LP diet tended to lower the concentrations of plasma leptin (P = 0.07), triglyceride (P = 0.05), and non-esterified FA (P = 0.08). Feeding a LP diet increased the enzyme activity or mRNA expression of lipogenic enzymes and decreased lipolytic enzymes compared with the NP diet. This effect was reversed by supplementation of RML with a LP diet. The inclusion of RML in a LP diet affected the polyunsaturated fatty acids (PUFA), n-3 PUFA, and n-6 PUFA in the liver but not in the muscle, which might be linked with altered expression of FA desaturase-1 (FADS1) and acetyl-CoA carboxylase (ACC). A LP diet supplemented with RML increased (P < 0.05) total m6A levels in the liver and muscle and were accompanied by decreased expression of fat mass and obesity-associated protein (FTO) and alkB homologue 5 (ALKBH5). The mRNA expressions of methyltransferase-like 3 (METTL3) and methyltransferase-like 14 (METTL14) in the LP + RML diet group were lower than those in the other two groups. Supplementation of RML with a LP diet affected only liver YTH domain family (YTHDF2) proteins (P < 0.05) and muscle YTHDF3 (P = 0.09), which can be explained by limited m6A-binding proteins that were mediated in mRNA fate.ConclusionsOur findings showed that the inclusion of RML in a LP diet could alter fat deposition through modulations of lipogenesis and lipolysis in the liver and muscle. These changes in fat metabolism may be associated with the modification of m6A RNA methylation.Graphical abstractA systematic graph illustrates the mechanism of dietary methionine and lysine influence on lipid metabolism and M6A. The green arrow with triangular heads indicates as activation and brown-wine arrows with flat heads indicates as suppression.

N6-methyladenosine (m6A) RNA methylation, one of the most widespread posttranscriptional modifications in eukaryotes, plays crucial roles in various developmental processes. The m6A modification process is catalyzed by a methyltransferase complex that includes Wilms tumor 1-associated protein (WTAP) as a key component. Whether the development of dental enamel is regulated by m6A RNA methylation in mammals remains unclear. Here, we reveal that WTAP is widely expressed from the early stage of tooth development. Specific inactivation of Wtap in mouse enamel epithelium by the Cre/loxp system leads to serious developmental defects in amelogenesis. In Wtap conditional KO mice, we determined that the differentiation of enamel epithelial cells into mature ameloblasts at the early stages of enamel development is affected. Mechanistically, loss of Wtap inhibits the expression of Sonic hedgehog (SHH), which plays an important role in the generation of ameloblasts from stem cells. Together, our findings provide new insights into the functional role of WTAP-mediated m6A methylation in amelogenesis in mammals.

The latest evidence suggested that the onset of dilated cardiomyopathy (DCM)is closely associated with immune microenvironment disturbance. Since N6 -methyladenosine (m6A) RNA methylation impacts on immunocyte function and antitumor immunity, it is predictable that m6A RNA methylation may result in immune microenvironment disorder. Here, we attempted to verify this hypothesis. We used single-sample gene set enrichment analysis (ssGSEA)to investigate the infiltration abundance of immunocytes, single-cell RNA-Seq to identify key m6A regulator, and a doxorubicin (Dox)-induced DCM mouse model to confirm our findings. ssGSEA revealed a higher infiltration abundance of CD8+ T lymphocytes, NK cells, monocytes, and B+ lymphocytes in DCM myocardium tissue. Single-cell RNA-Seq indicated a critical role of IGFBP2 in DCM. Cross-checking analysis hinted an interaction between IGFBP2 and NSUN5, ALYREF, RRP8, and ALKBH3. Mechanically, IGFBP2-mediated RNA methylation deteriorated the immune microenvironment and thus increased the risk of DCM by enhancing CD8+ T lymphocyte, NK cell, monocyte, B+ lymphocyte infiltration and activating check-point, MHC-I, and T cell co-stimulation signaling pathways. In the DCM mouse model, echocardiography indicated a significant reduction in ejection fraction (EF)and fractional shortening (FS)and an increase in left ventricular internal dimensions at systole (LVIDs)and diastole (LVIDd).MASSON staining indicated an increased fibrosis in myocardium tissue. qPCR and immunofluorescence staining indicated a significant increase in mRNA and protein levels of IGFBP2. The present study indicated that IGFBP2-mediated RNA methylation remodeled the immune microenvironment and increased the risk of DCM. IGFBP2 may serve as potential therapeutic target for DCM.