RNA methylation in hematological malignancies and its interactions with other epigenetic modifications

Inhibition of inflammation and apoptosis through the cyclic GMP-AMP synthase-stimulator of interferon genes pathway by stress granules after ALKBH5 demethylase activation during diabetic myocardial ischaemia-reperfusion injury

AIM

Post-transcriptional modifications and their specific mechanisms are the focus of research on the regulation of myocardial damage. Stress granules (SGs) can inhibit the inflammatory response by inhibiting the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway. This study investigated whether alkylation repair homologue protein 5 (ALKBH5) could affect myocardial inflammation and apoptosis during diabetic myocardial ischaemia-reperfusion injury (IRI) through the cGAS-STING pathway via SGs.

METHODS

A diabetes ischaemia-reperfusion rat model and a high glucose hypoxia/reoxygenation cell model were established. Adeno-associated virus (AAV) and lentivirus (LV) were used to overexpress ALKBH5, while the SG agonist arsenite (Ars) and the SG inhibitor anisomycin were used as interventions. Then, the levels of apoptosis and related indicators in the cell and rat models were measured.

RESULTS

In the in vivo experiment, compared with the normal sham group, the degree of myocardial tissue damage, creatine kinase-MB and cardiac troponin I in serum, and myocardial apoptosis, the infarcted area of myocardium, and the level of B-cell lymphoma 2 associated X protein, cGAS-STING pathway and inflammatory factors in the diabetes ischaemia-reperfusion group were significantly increased. However, the expression of SGs and the levels of ALKBH5, rat sarcoma-GTPase-activating protein-binding protein 1, T-cell intracellular antigen-1 and Bcl2 were significantly decreased. After AAV-ALKBH5 intervention, the degree of myocardial tissue damage, degree of myocardial apoptosis, and extent of myocardial infarction in myocardial tissue were significantly decreased. In the in vitro experiment, compared with those in the normal control group, the levels of lactate dehydrogenase, inflammation and apoptosis were significantly greater, and cell viability and the levels of ALKBH5 and SGs were decreased in the high glucose and hypoxia/reoxygenation groups. In the high glucose hypoxia/reoxygenation cell model, the degree of cell damage, inflammation, and apoptosis was greater than those in the high glucose and hypoxia/reoxygenation models, and the levels of ALKBH5 and SGs were further decreased. LV-ALKBH5 and Ars alleviated the degree of cell damage and inhibited inflammation and cell apoptosis. The inhibition of SGs could partly reverse the protective effect of LV-ALKBH5. The cGAS agonist G140 antagonized the inhibitory effects of the SG agonist Ars on cardiomyocyte apoptosis, inflammation and the cGAS-STING pathway.

CONCLUSION

Both ALKBH5 and SGs inhibited myocardial inflammation and apoptosis during diabetic myocardial ischaemia-reperfusion. Mechanistically, ALKBH5 might inhibit the apoptosis of cardiomyocytes by promoting the expression of SGs through the cGAS-STING pathway.

A chemically adjustable BMP6-IL6 axis in mesenchymal stem cells drives acute myeloid leukemia cell differentiation

Chemotherapy alone or in combination with allogeneic stem cell transplantation has been the standard of care for acute myeloid leukemia (AML) for decades. Leukemia relapse with limited treatment options remains the main cause of treatment failure. Therefore, an effective and safe approach to improve treatment outcomes is urgently needed for most AML patients. Mesenchymal stem cells (MSCs) have been reported to efficiently induce apoptosis and shape the fate of acute myeloid leukemia cells. Here, we identified LG190155 as a potent compound that enhances the antileukemia efficiency of MSCs. Pretreatment of MSCs with LG190155 significantly provoked differentiation in both AML patient-derived primary leukemia cells and AML cell lines and reduced the tumor burden in the AML mouse model. Using the quantitative proteomic technique, we discovered a pivotal mechanism that mediates AML cell differentiation, in which autocrine bone morphogenetic protein 6 (BMP6) in MSCs boosted IL-6 secretion and further acted on leukemic cells to trigger differentiation. Furthermore, the activity of the BMP6-IL6 axis was dramatically enhanced by activating vitamin D receptor (VDR) in MSCs. Our data illustrated an effective preactivated approach to reinforcing the antileukemia effect of MSCs, which could serve as an effective therapeutic strategy for AML.

Impaired binding affinity of YTHDC1 with METTL3/METTL14 results in R-loop accumulation in myelodysplastic neoplasms with DDX41 mutation

DEAD box helicase 41 (DDX41) mutations are the most prevalent predisposition to familial myelodysplastic syndrome (MDS). However, the precise roles of these variants in the pathogenesis of MDS have yet to be elucidated. Here, we discovered a novel mechanism by which DDX41 contributes to R-loop-induced DNA damage responses (DDR) in cooperation with the m6A-METTL complex (MAC) and YTHDC1 using DDX41 knockout (KO) and DDX41 knock-in (KI, R525H, Y259C) cell lines as well as primary samples from MDS patients. Compared to wild type (WT), DDX41 KO and KI led to increased levels of m6A RNA methylated R-loop. Interestingly, we found that DDX41 regulates m6A/R-loop levels by interacting with MAC components. Further, DDX41 promoted the recruitment of YTHDC1 to R-loops by promoting the binding between METTL3 and YTHDC1, which was dysregulated in DDX41-deficient cells, contributing to genomic instability. Collectively, we demonstrated that DDX41 plays a key role in the physiological control of R-loops in cooperation with MAC and YTHDC1. These findings provide novel insights into how defects in DDX41 influence MDS pathogenesis and suggest potential therapeutic targets for the treatment of MDS.

Prognostic value of RNA methylation-related genes in gastric adenocarcinoma based on bioinformatics

Background

Gastric cancer (GC) is a malignant tumor that originates from the epithelium of the gastric mucosa and has a poor prognosis. Stomach adenocarcinoma (STAD) covers 95% of total gastric cancer. This study aimed to identify the prognostic value of RNA methylation-related genes in gastric cancer.

Methods

In this study, The Cancer Genome Atlas (TCGA)-STAD and GSE84426 cohorts were downloaded from public databases. Patients were classified by consistent cluster analysis based on prognosis-related differentially expressed RNA methylation genes Prognostic genes were obtained by differential expression, univariate Cox and least absolute shrinkage and selection operator (LASSO) analyses. The prognostic model was established and validated in the training set, test set and validation set respectively. Independent prognostic analysis was implemented. Finally, the expression of prognostic genes was affirmed by reverse transcription quantitative PCR (RT-qPCR).

Results

In total, four prognostic genes (ACTA2, SAPCD2, PDK4 and APOD) related to RNA methylation were identified and enrolled into the risk signature. The STAD patients were divided into high- and low-risk groups based on the medium value of the risk score, and patients in the high-risk group had a poor prognosis. In addition, the RNA methylation-relevant risk signature was validated in the test and validation sets, and was authenticated as a reliable independent prognostic predictor. The nomogram was constructed based on the independent predictors to predict the 1/3/5-year survival probability of STAD patients. The gene set enrichment analysis (GSEA) result suggested that the poor prognosis in the high-risk subgroup may be related to immune-related pathways. Finally, the experimental results indicated that the expression trends of RNA methylation-relevant prognostic genes in gastric cancer cells were in agreement with the result of bioinformatics.

Conclusion

Our study established a novel RNA methylation-related risk signature for STAD, which was of considerable significance for improving prognosis of STAD patients and offering theoretical support for clinical therapy.

The role of RNA modification in urological cancers: mechanisms and clinical potential

RNA modification is a post-transcriptional level of regulation that is widely distributed in all types of RNAs, including mRNA, tRNA, rRNA, miRNA, and lncRNA, where N6-methyladenine (m6A) is the most abundant mRNA methylation modification. Significant evidence has depicted that m6A modifications are closely related to human diseases, especially cancer, and play pivotal roles in RNA transcription, splicing, stabilization, and translation processes. The most common urological cancers include prostate, bladder, kidney, and testicular cancers, accounting for a certain proportion of human cancers, with an ever-increasing incidence and mortality. The recurrence, systemic metastasis, poor prognosis, and drug resistance of urologic tumors have prompted the identification of new therapeutic targets and mechanisms. Research on m6A modifications may provide new solutions to the current puzzles. In this review, we provide a comprehensive overview of the key roles played by RNA modifications, especially m6A modifications, in urologic cancers, as well as recent research advances in diagnostics and molecularly targeted therapies.

Diagnostic Values of METTL1-Related Genes and Immune Characteristics in Systemic Lupus Erythematosus

Purpose

Methyltransferase like 1 (METTL1) regulates epitranscriptomes via the m7G modification in mammalian mRNA and microRNA. Systemic lupus erythematosus (SLE) is caused by abnormal immune reactivity and has diverse clinical manifestations. RNA methylation as a mechanism to regulate gene expression is widely implicated in immune regulation. However, the role of m7G in immune response of SLE has not been extensively studied.

Patients and Methods

Expression of METTL1 was identified in the public dataset GSE122459 and validated in an independent cohort of SLE patients. We investigated the association between METTL1-expression and clinical manifestations of SLE. Subsequently, differentially expressed genes (DEG) that were correlated with METTL1-expression in GSE122459 were used for functional enrichment analysis. The correlation between infiltrating immune cells and METTL1, as well as candidate biomarkers identified to be correlated with either METTL1 or immune cell infiltration were assessed by single-sample GSEA. Potential mechanisms were explored with Gene ontology and KEGG pathway enrichment. Diagnostic performances of candidate biomarkers in SLE were analyzed.

Results

The mRNA and protein expression of METTL1 in SLE patients were significantly decreased in both datasets. METTL1-coexpressed DEGs were enriched in several key immune-related pathways. Activated CD8 T cells, activated CD4 T cells, memory B cells and type 2 helper T cells were different between patients with high and low METTL1 expression. Further, activated CD8 T-cells, activated CD4 T-cells, memory B-cells were correlated with METTL1. The genes of LAMP3, CD83, PDCD1LG2, IGKVD3D-20, IGKV5-2, IGKV2D-30, IGLV3-19 and IGLV4-60 were identified as candidate targets that were correlated with immune cell proportion. Moreover, LAMP3, CD83, and PDCD1LG2 expression were of diagnostic value in SLE as indicated by ROC analysis.

Conclusion

Our findings suggested that METTL1 and its candidate targets LAMP3, CD83, PDCD1LG2 may be used for diagnosing SLE and could be explored for developing targeted molecular therapy for SLE.

Dynamic alterations of the transcriptome-wide m6A methylome in cytogenetically normal acute myeloid leukaemia during initial diagnosis and relapse

Accumulating studies have indicated that N6-methyladenosine (m6A) plays an important role in acute myeloid leukaemia (AML). However, little is known about the m6A methylome at a transcriptome-wide scale in AML patients. We obtained three pairs of bone marrow (BM) samples from cytogenetically normal AML patients at the timepoints of diagnosis (AML) and relapse (R_AML) and three BM samples from healthy donors used as normal controls (NCs). Methylated RNA immunoprecipitation next-generation sequencing (MeRIP-Seq) was conducted to identify differences in the m6A methylomes between AML and NC and between R_AML and AML. We identified a total of 11,076 and 11,962 differential m6A peaks in AML and R_AML group, respectively. These dysregulated m6A peaks were detected on all chromosomes, especially chr1, chr19 and chr17, and were mainly enriched in 3' untranslated regions, stop codon and coding sequence regions. Moreover, GO and KEGG analyses indicated that m6A -modified genes were significantly enriched in cancer-related biological functions and pathways. Additionally, we identified a link between the m6A methylome and RNA transcriptome via combined analyses of MeRIP-seq and RNA-seq data. In addition, 5 genes, HSPG2, HOMER3, TSPO2, CXCL12 and FUT1 regulated by m6A modification potentially, were shown to be related to the prognosis of AML patients. Additionally, we detected the mRNA expression of major m6A regulators and potential target mRNA on the leukemogenesis and found that the expression of IGF2BP2, HSPG2 and HOMER3 were upregulated in AML at the time of diagnosis. Moreover, their expression became downregulated after remission and then elevated again at relapse. Our study provides the first data on the differential m6A methylome in AML patients during initial diagnosis and relapse. This study demonstrates a novel relationship between m6A modification and AML relapse and paves the way for further studies aimed at elucidating the epigenic mechanisms involved in the relapse of AML.

Evaluation of FTO polymorphism in 6-mercaptopurine related intolerance in children with acute lymphoblastic leukemia

PURPOSE

Thiopurine drugs like 6-Mercaptopurine (6MP) are the cornerstone of maintenance therapy in acute lymphoblastic leukemia (ALL). A recently described variant in alpha-ketoglutarate dependent dioxygenase (FTO) gene has been reported to play an important role in thiopurine induced myelosuppression.

METHODS

In this study, we genotyped a coding variant (p.Ala134Thr, rs79206939) and an intronic variant (rs16952570) of FTO in 174 Indian children (age ≤ 12 years) with ALL on maintenance phase of chemotherapy and examined correlation with the risk of thiopurine induced myelosuppression and hepatic toxicity.

RESULTS

The prevalence of FTO-rs16952570 polymorphism was 18.4% (32/174) with 142 (82%) cases having TT genotype, 26 (15%) cases with TC genotype and 6 (3.4%) cases having CC genotype. FTO-rs79206939 was absent and non-polymorphic in our study group. The mean dose of 6-MP during 36 weeks of maintenance of TT, TC and CC carriers of FTO-rs16952570 was 53.7, 53.6 and 54.1 mg/m2/day. Number of patients tolerating starting dose of 60 mg/m2/day was significantly higher in CC (50%) than TT/TC (14%) genotype carrying cases (p = 0.014). However, no statistical significance was observed for total leukocyte count (TLC), absolute neutrophil count (ANC) as well as for platelets counts in patients harboring FTO-rs16952570 TT/TC/CC genotype at 4, 8, 12, 24 and 36 weeks after start of thiopurine therapy. Further, no significant correlation was noted between number of weeks of chemotherapy interruptions or episodes of febrile neutropenia and no evidence of hepatotoxicity was found with the genotype studied.

CONCLUSION

Polymorphism in FTO-rs16952570 did not show any correlation with thiopurine related toxicity in ALL patients.

The essential roles of small non-coding RNAs and RNA modifications in normal and malignant hematopoiesis

Hematopoietic stem cells (HSCs) developing from mesoderm during embryogenesis are important for the blood circulatory system and immune system. Many factors such as genetic factors, chemical exposure, physical radiation, and viral infection, can lead to the dysfunction of HSCs. Hematological malignancies (involving leukemia, lymphoma, and myeloma) were diagnosed in more than 1.3 million people globally in 2021, taking up 7% of total newly-diagnosed cancer patients. Although many treatments like chemotherapy, bone marrow transplantation, and stem cell transplantation have been applied in clinical therapeutics, the average 5-year survival rate for leukemia, lymphoma, and myeloma is about 65%, 72%, and 54% respectively. Small non-coding RNAs play key roles in a variety of biological processes, including cell division and proliferation, immunological response and cell death. With the development of technologies in high-throughput sequencing and bioinformatic analysis, there is emerging research about modifications on small non-coding RNAs, as well as their functions in hematopoiesis and related diseases. In this study, we summarize the updated information of small non-coding RNAs and RNA modifications in normal and malignant hematopoiesis, which sheds lights into the future application of HSCs into the treatment of blood diseases.

Emerging role of mRNA methylation in regulating the hallmarks of cancer

The dynamic chemical modifications of DNA, RNA, and proteins can transform normal cells into malignant ones. While the DNA and protein modifications in cancer have been described extensively in the literature, there are fewer reports about the role of RNA modifications in cancer. There are over 100 forms of RNA modifications and one of these, mRNA methylation, plays a critical role in the malignant properties of the cells. mRNA methylation is a reversible modification responsible for regulating protein expression at the post-transcriptional level. Despite being discovered in the 1970s, a complete understanding of the different proteins involved and the mechanism behind mRNA methylation remains largely unknown. However, these mRNA methylations have been shown to foster cancer hallmarks via specific cellular targets inside the cell. In this review, we provide a brief overview of mRNA methylation and its emerging role in regulating the various hallmarks of cancer.

SWI/SNF complexes in hematological malignancies: biological implications and therapeutic opportunities

Hematological malignancies are a highly heterogeneous group of diseases with varied molecular and phenotypical characteristics. SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complexes play significant roles in the regulation of gene expression, being essential for processes such as cell maintenance and differentiation in hematopoietic stem cells. Furthermore, alterations in SWI/SNF complex subunits, especially in ARID1A/1B/2, SMARCA2/4, and BCL7A, are highly recurrent across a wide variety of lymphoid and myeloid malignancies. Most genetic alterations cause a loss of function of the subunit, suggesting a tumor suppressor role. However, SWI/SNF subunits can also be required for tumor maintenance or even play an oncogenic role in certain disease contexts. The recurrent alterations of SWI/SNF subunits highlight not only the biological relevance of SWI/SNF complexes in hematological malignancies but also their clinical potential. In particular, increasing evidence has shown that mutations in SWI/SNF complex subunits confer resistance to several antineoplastic agents routinely used for the treatment of hematological malignancies. Furthermore, mutations in SWI/SNF subunits often create synthetic lethality relationships with other SWI/SNF or non-SWI/SNF proteins that could be exploited therapeutically. In conclusion, SWI/SNF complexes are recurrently altered in hematological malignancies and some SWI/SNF subunits may be essential for tumor maintenance. These alterations, as well as their synthetic lethal relationships with SWI/SNF and non-SWI/SNF proteins, may be pharmacologically exploited for the treatment of diverse hematological cancers.

Identification of Genes with Altered Methylation in Osteoclast Differentiation and Its Roles in Osteoporosis

Osteoporosis is one of the most common metabolic skeletal diseases, which affects more than 200 million people worldwide, especially elderly and postmenopausal women. One of the main processes of osteoporosis is attenuated bone formation. Abundant evidence has confirmed that overactivated osteoclasts are responsible for the attenuated bone formation. This study aims at identifying novel methylation-associated biomarkers and therapeutic targets in osteoclasts by integrally analyzing methylation profiles and gene expression data. DNA methylation profile and gene expression data were obtained from the Gene Expression Omnibus (GEO) database. Subsequently, we integrated the two sets of data to screen for differentially expressed genes with differential methylation level (DM-DEGs) between osteoclasts and CD14⁺ monocytes from donors. Then, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to uncover the enriched functions and pathways of identified DM-DEGs. In addition, by combining protein-protein interaction analysis and receiver-operator characteristic analysis, we finally identified four hub DM-DEGs. Gene Set Enrichment Analysis was utilized to validate and investigate the potential biological functions of the four hub DM-DEGs. Finally, Real-time quantitative PCR (QPCR) was performed to validate the mRNA expression level of the four identified hub DM-DEGs during osteoclast differentiation. CCRL2, CCL18, C1QB, and SELL were highly correlated with osteoclastic differentiation and osteoporosis phenotype. QPCR revealed that the expression of CCRL2, CCL18, and C1QB was increased during osteoclast differentiation, whereas the expression of SELL was decreased. The present study indicated a connection between gene expression and DNA methylation during osteoclast differentiation and that four hub DM-DEGs in osteoclastogenesis and osteoporosis pathogenesis might be potential candidates for intensive research and therapeutic targets for the treatment of osteoporosis.

The Interaction Between Epigenetic Changes, EMT, and Exosomes in Predicting Metastasis of Colorectal Cancers (CRC)

Worldwide, colorectal cancer (CRC) ranks as the third most common malignancy, and the second most deadly with nearly one million attributable deaths in 2020. Metastatic disease is present in nearly 25% of newly diagnosed CRC, and despite advances in chemotherapy, less than 20% will remain alive at 5 years. Epigenetic change plays a key role in the epithelial-to-mesenchymal transition (EMT), which is a crucial phenotype for metastasis and mainly includes DNA methylation, non-coding RNAs (ncRNAs), and N6-methyladenosine (m6A) RNA, seemingly valuable biomarkers in CRCs. For ncRNAs, there exists a “molecular sponge effect” between long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). The detection of exosomes is a novel method in CRC monitoring, especially for predicting metastasis. There is a close relationship between exosomes and EMT in CRCs. This review summarizes the close relationship between epigenetic changes and EMT in CRCs and emphasizes the crucial function of exosomes in regulating the EMT process.

N6-Methyladenosine-Related lncRNAs Are Novel Prognostic Markers and Predict the Immune Landscape in Acute Myeloid Leukemia

Background: Acute myelocytic leukemia (AML) is one of the hematopoietic cancers with an unfavorable prognosis. However, the prognostic value of N 6-methyladenosine-associated long non-coding RNAs (lncRNAs) in AML remains elusive.

Materials and Methods: The transcriptomic data of m6A-related lncRNAs were collected from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. AML samples were classified into various subgroups according to the expression of m6A-related lncRNAs. The differences in terms of biological function, tumor immune microenvironment, copy number variation (CNV), and drug sensitivity in AML between distinct subgroups were investigated. Moreover, an m6A-related lncRNA prognostic model was established to evaluate the prognosis of AML patients.

Results: Nine prognosis-related m6A-associated lncRNAs were selected to construct a prognosis model. The accuracy of the model was further determined by the Kaplan–Meier analysis and time-dependent receiver operating characteristic (ROC) curve. Then, AML samples were classified into high- and low-risk groups according to the median value of risk scores. Gene set enrichment analysis (GSEA) demonstrated that samples with higher risks were featured with aberrant immune-related biological processes and signaling pathways. Notably, the high-risk group was significantly correlated with an increased ImmuneScore and StromalScore, and distinct immune cell infiltration. In addition, we discovered that the high-risk group harbored higher IC50 values of multiple chemotherapeutics and small-molecule anticancer drugs, especially TW.37 and MG.132. In addition, a nomogram was depicted to assess the overall survival (OS) of AML patients. The model based on the median value of risk scores revealed reliable accuracy in predicting the prognosis and survival status.

Conclusion: The present research has originated a prognostic risk model for AML according to the expression of prognostic m6A-related lncRNAs. Notably, the signature might also serve as a novel biomarker that could guide clinical applications, for example, selecting AML patients who could benefit from immunotherapy.

The Status and Prospects of Epigenetics in the Treatment of Lymphoma

The regulation of gene transcription by epigenetic modifications is closely related to many important life processes and is a hot research topic in the post-genomic era. Since the emergence of international epigenetic research in the 1990s, scientists have identified a variety of chromatin-modifying enzymes and recognition factors, and have systematically investigated their three-dimensional structures, substrate specificity, and mechanisms of enzyme activity regulation. Studies of the human tumor genome have revealed the close association of epigenetic factors with various malignancies, and we have focused more on mutations in epigenetically related regulatory enzymes and regulatory recognition factors in lymphomas. A number of studies have shown that epigenetic alterations are indeed widespread in the development and progression of lymphoma and understanding these mechanisms can help guide clinical efforts. In contrast to chemotherapy which induces cytotoxicity, epigenetic therapy has the potential to affect multiple cellular processes simultaneously, by reprogramming cells to achieve a therapeutic effect in lymphoma. Epigenetic monotherapy has shown promising results in previous clinical trials, and several epigenetic agents have been approved for use in the treatment of lymphoma. In addition, epigenetic therapies in combination with chemotherapy and/or immunotherapy have been used in various clinical trials. In this review, we present several important epigenetic modalities of regulation associated with lymphoma, summarize the corresponding epigenetic drugs in lymphoma, and look at the future of epigenetic therapies in lymphoma.

The role of m6A methylation in osteosarcoma biological processes and its potential clinical value

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and young adults and has a poor prognosis. Recent developments in the field of high-throughput sequencing technology, particularly in methylated RNA immunoprecipitation sequencing (MeRIP-seq), have led to renewed interest in RNA methylation. Among the various RNA modifications, N6-methyladenosine (m6A) modifications are the most common. Emerging evidence suggests that m6A methylation can affect the complexity of cancer progression by regulating biological functions related to cancer. In this review, we will shed light on recent findings regarding the biological function of m6A methylation in OS and discuss future research directions and potential clinical applications of RNA methyltransferases in OS.

Current Advances in N6-Methyladenosine Methylation Modification During Bladder Cancer

N6-methyladenosine (m6A) is a dynamic, reversible post-transcriptional modification, and the most common internal modification of eukaryotic messenger RNA (mRNA). Considerable evidence now shows that m6A alters gene expression, thereby regulating cell self-renewal, differentiation, invasion, and apoptotic processes. M6A methylation disorders are directly related to abnormal RNA metabolism, which may lead to tumor formation. M6A methyltransferase is the dominant catalyst during m6A modification; it removes m6A demethylase, promotes recognition by m6A binding proteins, and regulates mRNA metabolic processes. Bladder cancer (BC) is a urinary system malignant tumor, with complex etiology and high incidence rates. A well-differentiated or moderately differentiated pathological type at initial diagnosis accounts for most patients with BC. For differentiated superficial bladder urothelial carcinoma, the prognosis is normally good after surgery. However, due to poor epithelial cell differentiation, BC urothelial cell proliferation and infiltration may lead to invasive or metastatic BC, which lowers the 5-years survival rate and significantly affects clinical treatments in elderly patients. Here, we review the latest progress in m6A RNA methylation research and investigate its regulation on BC occurrence and development.

New advances of DNA/RNA methylation modification in liver fibrosis

Liver fibrosis is a complex pathological process caused by multiple pathogenic factors，such as ethanol, viruses, toxins, drugs or cholestasis, and it can eventually develop into liver cirrhosis without effective treatment. Activation of hepatic stellate cells (HSCs) is a pivotal cellular event in the pathogenesis of liver fibrosis. However, the pathogenesis of liver fibrosis has not been fully elucidated. DNA/RNA methylation can regulate gene expression without alteration in its sequence, and numerous studies have shown the involvement of DNA methylation in the activation of HSCs and then promote the progression of liver fibrosis. In addition, RNA methylation has recently been reported to play a regulatory role in this process. In this review, we focus on the aberrant DNA/RNA methylation of selected genes and explore their functional mechanism in regulating HSCs activation and liver fibrogenesis. All of these findings will enhance our understanding of DNA/RNA methylation and their roles in liver fibrosis and provide the basis to identify effective therapeutic targets.

Strategies and Perspectives for UV Resonance Raman Applicability in Clinical Analyses of Human Sperm RNA

Developing a deeper knowledge about the impact of DNA and RNA epigenetic mutations on sperm production and fertilization performance is essential for selecting best quality samples in Assisted Reproductive Technologies (ART). Indeed, sperm RNAs adenine and guanine are likely to be methylated in low quality RNA sperm samples and their study requires the employment of techniques able to isolate high quality nucleic acids. UV resonance Raman spectroscopy represents a valuable tool that is able to monitor peculiar molecular modifications occurring predominantly in nucleic acids, being less sensitive to the presence of other biological compounds. In this work, we used an UV Resonance Raman (UVRR) setup coupled to a synchrotron radiation source tuned at 250 nm, in order to enhance sperm RNAs adenine and guanine vibrational signals, reducing also the impact of a fluorescence background typically occurring at lower energies. Despite that our protocol should be further optimized and further analyses are requested, our results support the concept that UVRR can be applied for setting inexpensive tools to be employed for semen quality assessment in ART.