bims-rimeca 2024-01-07 papers

bims-rimeca

Biomed News

on RNA methylation in cancer

Issue of 2024–01–07
28 papers selected by
Sk Ramiz Islam, Saha Institute of Nuclear Physics

Link between m6A modification and infiltration characterization of tumor microenvironment in lung adenocarcinoma.
METTL3-dependent N6-methyladenosine modification is involved in berberine-mediated neuroprotection in ischemic stroke by enhancing the stability of NEAT1 in astrocytes.
METTL3 promotes microglial inflammation via MEF2C in spinal cord injury.
Regulatory effects of natural products on N6-methyladenosine modification: A novel therapeutic strategy for cancer.
Programmable protein expression using a genetically encoded m6A sensor.
Knockdown of fat mass and obesity alleviates the ferroptosis in Parkinson's disease through m6A-NRF2-dependent manner.
Investigating the prognostic value of m6A methylation-related genes in renal cell carcinoma patients.
Dietary selenomethionine reduced oxidative stress by resisting METTL3-mediated m6A methylation level of Nrf2 to ameliorate LPS-induced liver necroptosis in laying hens.
RNA m6A methylation regulators in liver cancer.
ω-3PUFAs Inhibit Hypoxia-Induced Retinal Neovascularization via Regulating Microglial Pyroptosis through METTL14-Mediated m6A Modification of IFNB1 mRNA.
PIGT promotes cell growth, glycolysis, and metastasis in bladder cancer by modulating GLUT1 glycosylation and membrane trafficking.
Exploring the prognostic potential of m6A methylation regulators in low-grade glioma: implications for tumor microenvironment modulation.
Emerging roles and mechanism of m6A methylation in rheumatoid arthritis.
WTAP-mediated m6A modification of FRZB triggers the inflammatory response via the Wnt signaling pathway in osteoarthritis.
m6A-modified circARHGAP12 promotes the aerobic glycolysis of doxorubicin-resistance osteosarcoma by targeting c-Myc.
The role of the methyltransferase METTL3 in prostate cancer: a potential therapeutic target.
The m6A reader YTHDC2 maintains visual function and retinal photoreceptor survival through modulating translation of PPEF2 and PDE6B.
DDX5 inhibits inflammation by modulating m6A levels of TLR2/4 transcripts during bacterial infection.
LRRC75A-AS1 drives the epithelial-mesenchymal transition in cervical cancer by binding IGF2BP1 and inhibiting SYVN1-mediated NLRP3 ubiquitination.
Comprehensive analysis of m6A reader YTHDF2 prognosis, immune infiltration, and related regulatory networks in hepatocellular carcinoma.
N6-methyladenosine in myeloid cells: a novel regulatory factor for inflammation-related diseases.
Protocol to analyze the role of various metabolites in impacting global RNA 5-methylcytosine levels in cultured cells by dot blot.
N6 methyladenosine eraser FTO suppresses Staphylococcus aureus-induced ferroptosis of bone marrow mesenchymal stem cells to ameliorate osteomyelitis through regulating the MDM2/TLR4/SLC7A11 signaling pathway.
YTHDC1 delays cellular senescence and pulmonary fibrosis by activating ATR in an m6A-independent manner.
METTL3 drives telomere targeting of TERRA lncRNA through m6A-dependent R-loop formation: a therapeutic target for ALT-positive neuroblastoma.
Modifying the antiviral innate immune response by selective writing, erasing, and reading of m6A on viral and cellular RNA.
Pharmacological inhibition of MYC to mitigate chemoresistance in preclinical models of squamous cell carcinoma.
N-acetyltransferase 10 regulates alphavirus replication via N4-acetylcytidine (ac4C) modiﬁcation of the lymphocyte antigen six family member E (LY6E) mRNA.

Exp Biol Med (Maywood). 2024 Jan 02. 15353702231214266

Link between m6A modification and infiltration characterization of tumor microenvironment in lung adenocarcinoma.

Sha Yang, Ke Li, Jiqin Zhang, Jian Liu, Lin Liu, Ying Tan, Chuan Xu.

  N6-methyladenosine (m6A) RNA methylation plays a pivotal role in immune responses and the onset and advancement of cancer. Nonetheless, the precise impact of m6A modification in lung adenocarcinoma (LUAD) and its associated tumor microenvironment (TME) remains to be fully elucidated. Here, we distinguished distinct m6A modification patterns within two separate LUAD cohorts using a set of 21 m6A regulators. The TME characteristics associated with these two patterns align with the immune-inflamed and immune-excluded phenotypes, respectively. We identified 2064 m6A-related genes, which were used as a basis to divide all LUAD samples into three distinct m6A gene clusters. We applied a scoring system to evaluate the m6A gene signature of the m6A modification pattern in individual patients. To authenticate the categorization significance of m6A modification patterns, we established a correlation between m6A score and TME infiltration profiling, tumor somatic mutations, and responses to immunotherapy. A high level of m6A modification may be associated with the aggressiveness and poor prognosis of LUAD. Further studies should investigate the mechanism of action of m6A regulators and m6A-related genes to improve the diagnosis and treatment of patients with LUAD.

Keywords:  immunotherapy; lung adenocarcinoma; m6A; stroma; tumor microenvironment; tumor somatic mutation

DOI:  https://doi.org/10.1177/15353702231214266
Aging (Albany NY). 2024 Jan 04. 15

METTL3-dependent N6-methyladenosine modification is involved in berberine-mediated neuroprotection in ischemic stroke by enhancing the stability of NEAT1 in astrocytes.

Junya Hu, Huijie Duan, Junqing Zou, Wangli Ding, Ziqiao Wei, Qiang Peng, Zhongyuan Li, Rui Duan, Jianguo Sun, Junrong Zhu.

  Ischemic stroke (IS) is one of the principal causes of disability and death worldwide. Berberine (BBR), derived from the traditional Chinese herbal medicine Huang Lian, has been reported to inhibit the progression of stroke, but the specific mechanism whereby BBR modulates the progression of ischemic stroke remains unclear. N6-methyladenosine (m6A) modification is the most typical epigenetic modification of mRNA post-transcriptional modifications, among which METTL3 is the most common methylation transferase. During the study, the middle cerebral artery occlusion/reperfusion (MCAO/R) was established in mice, and the mice primary astrocytes and neurons induced by oxygen-glucose deprivation/reoxygenation (OGD/R) was simulated in vitro. Level of LncNEAT1, miR-377-3p was detected via RT-qPCR. The levels of Nampt and METTL3 were measured by Western blot. CCK8 and LDH assay was performed to detect cell viability. Here, we found that berberine alleviates MCAO/R-induced ischemic injury and up-regulates the expression of Nampt in astrocytes, miR-377-3p inhibits the expression of Nampt in astrocytes after OGD/R, thus promoting neuronal injury. NEAT1 binds to miR-377-3p in OGD/R astrocytes and plays a neuronal protective role as a ceRNA. METTL3 can enhance NEAT1 stability in OGD/R astrocytes by modulating m6A modification of NEAT1. Taken together, our results demonstrate that berberine exerts neuroprotective effects via the m6A methyltransferase METTL3, which regulates the NEAT1/miR-377-3p/Nampt axis in mouse astrocytes to ameliorate cerebral ischemia/reperfusion (I/R) injury.

Keywords:  Nampt; astrocytes; berberine; ischemic stroke; m6A

DOI:  https://doi.org/10.18632/aging.205369
Cell Tissue Res. 2024 Jan 05.

METTL3 promotes microglial inflammation via MEF2C in spinal cord injury.

Dongliang Wang, Wei Qian, Duanrong Wu, Ya Wu, Kun Lu, Guoyou Zou.

  Spinal cord injury (SCI) is a significant contributor to disability in contemporary society, resulting in substantial psychological and economic burdens for patients and their family. Microglia-mediated inflammation is an important factor affecting the nerve repair of SCI patients. N6-methyladenosine (m6A) is a prevalent epigenetic modification in mammals, which shows a strong association with inflammation. However, the mechanism of m6A modification regulating microglia-mediated inflammation is still unclear. Here, we observed that METTL3, a m6A methylase, was increased in SCI mice and lipopolysaccharide (LPS)-exposed BV2 cells. Knockdown of METTL3 inhibited the increased expression of iNOS and IL-1β induced by LPS in vitro. Subsequently, MEF2C, myocyte-specific enhancer factor 2C, was decreased in SCI mice and LPS-exposed BV2 cells. Knockdown of MEF2C promoted the expression of iNOS and IL-1β. Sequence analysis showed that there were multiple highly confident m6A modification sites on the MEF2C mRNA. METTL3 antibody could pull down a higher level of MEF2C mRNA than the IgG in RNA binding protein immunoprecipitation assay. Knockdown of METTL3 promoted MEF2C protein expression and MEF2C mRNA expression, accompanied by a reduced m6A modification level on the MEF2C mRNA. Knockdown of MEF2C inhibited the anti-inflammatory effect of METTL3 siRNA. Our results suggest that METTL3 promotes microglia inflammation via regulating MEF2C mRNA m6A modification induced by SCI and LPS treatment.

Keywords:  Inflammation; METTL3; Microglia; Spinal cord injury

DOI:  https://doi.org/10.1007/s00441-023-03855-6
Drug Discov Today. 2024 Jan 02. pii: S1359-6446(23)00391-4. [Epub ahead of print] 103875

Regulatory effects of natural products on N6-methyladenosine modification: A novel therapeutic strategy for cancer.

Mao-Mao, Jin-Jing Zhang, Yue-Ping Xu, Min-Min Shao, Meng-Chuan Wang.

  N6-methyladenosine (m6A) is considered to be the most common and abundant epigenetics modification in messenger RNA (mRNA) and noncoding RNA. Abnormal modification of m6A is closely related to the occurrence, development, progression, and prognosis of cancer. m6A regulators have been identified as novel targets for anticancer drugs. Natural products, a rich source of traditional anticancer drugs, have been utilized for the development of m6A-targeting drugs. Here, we review the key role of m6A modification in cancer progression and explore the prospects and structural modification mechanisms of natural products as potential drugs targeting m6A modification for cancer treatment. Teaser The key role of m6A modification in cancer progression and prospects of natural products as potential drugs targeting m6A modification for cancer therapy are explored.

Keywords:  RNA methylation; anticancer; drug discovery; m6A; natural product

DOI:  https://doi.org/10.1016/j.drudis.2023.103875
Nat Biotechnol. 2024 Jan 02.

Programmable protein expression using a genetically encoded m6A sensor.

Bahjat F Marayati, Matthew G Thompson, Christopher L Holley, Stacy M Horner, Kate D Meyer.

The N6-methyladenosine (m6A) modification is found in thousands of cellular mRNAs and is a critical regulator of gene expression and cellular physiology. m6A dysregulation contributes to several human diseases, and the m6A methyltransferase machinery has emerged as a promising therapeutic target. However, current methods for studying m6A require RNA isolation and do not provide a real-time readout of mRNA methylation in living cells. Here we present a genetically encoded m6A sensor (GEMS) technology, which couples a fluorescent signal with cellular mRNA methylation. GEMS detects changes in m6A caused by pharmacological inhibition of the m6A methyltransferase, giving it potential utility for drug discovery efforts. Additionally, GEMS can be programmed to achieve m6A-dependent delivery of custom protein payloads in cells. Thus, GEMS is a versatile platform for m6A sensing that provides both a simple readout for m6A methylation and a system for m6A-coupled protein expression.

DOI: https://doi.org/10.1038/s41587-023-01978-3
Cell Biol Int. 2024 Jan 05.

Knockdown of fat mass and obesity alleviates the ferroptosis in Parkinson's disease through m6A-NRF2-dependent manner.

Pengfei Pang, Shirong Zhang, Xinxin Fan, Shitao Zhang.

  Emerging evidence has suggested that N6 -methyladenosine (m6 A) regulates the pathology of Parkinson's disease (PD). Nevertheless, the function of demethylase fat mass and obesity (FTO) associated pathogenesis is still not fully elucidated. Here, this research findings revealed that m6 A-modification was decreased in PD models, meanwhile, the FTO level upregulated in the PD models. Functionally, in N-methyl-4-phenylpyridinium (MPP+) treated SH-SY5Y cells, the ferroptosis significantly upregulated and FTO silencing mitigated the ferroptosis phenotype. Moreover, in silico assays indicated that nuclear factor erythroid 2-related factor-2 (NRF2) acted as the target of FTO, and FTO demethylated the m6 A modification from NRF2 mRNA. Furthermore, FTO impaired the NRF2 mRNA stability via m6 A-dependent pathway. Thus, our findings illustrated an important role of FTO on PD through m6 A-NRF2-ferroptosis manner. Taken together, the study revealed the potential function of FTO on PD nervous system diseases.

Keywords:  N6-methyladenosine; Parkinson's disease; fat mass and obesity; ferroptosis; nuclear factor erythroid 2-related factor-2

DOI:  https://doi.org/10.1002/cbin.12118
Eur Rev Med Pharmacol Sci. 2023 Dec;pii: 34793. [Epub ahead of print]27(24): 11932-11946

Investigating the prognostic value of m6A methylation-related genes in renal cell carcinoma patients.

G-C Ge, C-H Wang.

OBJECTIVE: The objective of this research was to explore the importance of N6-methyladenosine (m6A) methylation-associated genes concerning the clinical outcome of patients with renal cell carcinoma (RCC) by employing the Cancer Genome Atlas (TCGA) database along with various bioinformatics methodologies.
MATERIALS AND METHODS: The transcriptome and clinical data of RCC patients were obtained from the TCGA database. We identified the differential expression of 13 genes and selected potential predictive genes for further analysis of their prognostic values.
RESULTS: Ten genes (YTHDC2, FTO, YTHDF2, METTL3, KIAA1429, ZC3H13, METTL14, ALKBH5, WTAP, and RBM15) exhibited altered expression levels in RCC. Subgroup analysis based on m6A methylation-related gene expression levels revealed no significant differences in survival rates, but significant differences were observed in grade, T stage, and gender. Five potential predictors (FTO, RBM15, YTHDC2, ZC3H13b, and ALKBH5) demonstrated independent predictive value. Multivariate analysis selected two regulators (METTL14 and METTL3), and based on these, prognostic signals for RCC were constructed, independent of potential confounding factors. The model clearly distinguished between samples with good and poor prognoses.
CONCLUSIONS: The expression levels of m6A methylation-related genes in RCC patients were found to differ and were associated with survival rates and prognosis. These findings suggest that m6A methylation-related genes could serve as prognostic indicators and promising therapeutic targets for RCC patients.

DOI: https://doi.org/10.26355/eurrev_202312_34793
J Nutr Biochem. 2024 Jan 02. pii: S0955-2863(23)00296-6. [Epub ahead of print] 109563

Dietary selenomethionine reduced oxidative stress by resisting METTL3-mediated m6A methylation level of Nrf2 to ameliorate LPS-induced liver necroptosis in laying hens.

Shanshan Li, Yixuan Wang, Anqi Xu, Bing Zhao, Yu Xia, Yujiao He, Hua Xue, Shu Li.

  Selenomethionine (SeMet) as the main form of daily dietary selenium, occupies essential roles in providing antioxidant and anti-inflammatory properties, which alleviates inflammatory liver damage. N6-methyladenosine (m6A) is one of the most prevalent and abundant internal transcriptional modifications that regulate gene expression. To investigate the protective mechanism of SeMet on liver injury and the regulatory effect of m6A methylation modification, we established the model by supplementing dietary SeMet, and LPS as stimulus in laying hens. LMH cells were intervened with SeMet (0.075 μM) and/or LPS (60 μg/mL). Subsequently, histopathology and ultrastructure of liver were observed. Western Blot, qRT-PCR, colorimetry, MeRIP-qPCR, fluorescent probe staining and AO/EB were used to detect total m6A methylation level, m6A methylation level of Nrf2, ROS, inflammatory and necroptosis factors. Studies showed that SeMet suppressed LPS-induced upregulation of total m6A methylation levels and METTL3 expression. Interestingly, SeMet reduced the m6A methylation level of Nrf2, activated antioxidant pathways and alleviated oxidative stress. LMH cells were transfected with 50 μm siMETTL3. SeMet/SiMETTL3 reversed the LPS-induced reduction in Nrf2 mRNA stability, slowed down its degradation rate. Moreover, LPS induced oxidative stress, led to necroptosis and activated NF-κB to promote the expression of inflammatory factors. SeMet/SiMETTL3 alleviated LPS-induced necroptosis and inflammation. Altogether, SeMet enhanced antioxidant and anti-inflammatory capacity by reducing METTL3-mediated m6A methylation levels of Nrf2, ultimately alleviating liver damage. Our findings provided new insights and therapeutic target for the practical application of dietary SeMet in the treatment and prevention of liver inflammation, and supplied a reference for comparative medicine.

Keywords:  Inflammation; M(6)A methylation; Necroptosis; Nrf2; Oxidative stress; SeMet

DOI:  https://doi.org/10.1016/j.jnutbio.2023.109563
Cancer Cell Int. 2024 Jan 02. 24(1): 1

RNA m6A methylation regulators in liver cancer.

Qiaoping Xu, Ning Ren, Lanqi Ren, Yibei Yang, Junjie Pan, Hongkai Shang.

Liver cancer is one of the most common cancers in the world and a primary cause of cancer-related death. In recent years, despite the great development of diagnostic methods and targeted therapies for liver cancer, the incidence and mortality of liver cancer are still on the rise. As a universal post-transcriptional modification, N6-methyladenosine (m6A) modification accomplishes a dynamic and reversible m6A modification process, which is executed by three types of regulators, methyltransferases (called writers), demethylases (called erasers) and m6A-binding proteins (called readers). Many studies have shown that m6A RNA methylation has an important impact on RNA metabolism, whereas its regulation exception is bound up with the occurrence of human malignant tumors. Aberrant methylation of m6A RNA and the expression of related regulatory factors may be of the essence in the pathogenesis and progression of liver cancer, yet the precise molecular mechanism remains unclear. In this paper, we review the current research situations of m6A methylation in liver cancer. Among the rest, we detail the mechanism by which methyltransferases, demethylases and m6A binding proteins regulate the occurrence and development of liver cancer by modifying mRNA. As well as the potential effect of m6A regulators in hepatocarcinogenesis and progression. New ideas and approaches will be given to the prevention and treatment of liver cancer through the following relevant research results.

DOI: https://doi.org/10.1186/s12935-023-03197-x
Appl Biochem Biotechnol. 2024 Jan 04.

ω-3PUFAs Inhibit Hypoxia-Induced Retinal Neovascularization via Regulating Microglial Pyroptosis through METTL14-Mediated m6A Modification of IFNB1 mRNA.

Shun Wang, Jing Zhang, Jun Chen, Lanlan Tang, Min Ke, Yanni Xue, Ying He, Yan Gong, Zhi Li.

  Retinal neovascular disease is the leading reason of vision impairment in all ages. Here, we figured out the function and mechanism of omega-3 polyunsaturated fatty acids (ω-3PUFAs) in hypoxia-induced retinal neovascularization by focusing on microglial pyroptosis. Microglia BV-2 cells were given ω-3PUFAs treatment and co-cultured with mouse retinal microvascular endothelial cells (MRMECs) under hypoxia. Tube formation assay, transwell assay and wound healing assay were utilized to monitor the MRMEC angiogenesis. Cell counting kit-8, western blot, lactate dehydrogenase assay, and enzyme-linked immunosorbent assay were used to assess pyroptosis of BV-2 cells. RNA sequencing and methylated RNA immunoprecipitation-polymerase chain reaction were utilized to identify the target gene of methyltransferase-like 14 (METTL14) and its N6-methyladenosine (m6A) level in BV-2 cells. BV-2 cells prominently enhanced MRMEC angiogenesis under hypoxia, but this effect was abolished after ω-3PUFAs treatment. ω-3PUFAs inhibited pyroptosis in hypoxia-induced BV-2 cells, and BV-2 cell pyroptosis boosted angiogenesis of MRMECs. Additionally, ω-3PUFAs markedly augment the expression of MELLL14 in BV-2 cells, and METTL14 knockdown promoted BV-2 cell pyroptosis and BV-2 cell-mediated angiogenesis in MEMECs. Mechanistically, interferon beta 1 (IFNB1) was a target of METTL14, and METTL14 silencing increased the mRNA expression and decreased the m6A modification of IFNB1 in BV-2 cells. Our results uncovered that ω-3PUFAs diminished hypoxia-induced retinal neovascularization through controlling microglial pyroptosis via METTL14-mediated m6A modification. This study offers a novel potential target for the treatment of retinal neovascular diseases.

Keywords:  Microglia; Pyroptosis; Retinal Neovascularization; m6A Modification; ω-3PUFAs

DOI:  https://doi.org/10.1007/s12010-023-04795-1
J Transl Med. 2024 Jan 02. 22(1): 5

PIGT promotes cell growth, glycolysis, and metastasis in bladder cancer by modulating GLUT1 glycosylation and membrane trafficking.

Mingyue Tan, Qi Pan, Chao Yu, Xinyu Zhai, Jianyi Gu, Le Tao, Dongliang Xu.

   BACKGROUND: Bladder cancer is very common worldwide. PIGT is a subunit of the glycosylphosphatidylinositol transamidase which involves in tumorigenesis and invasiveness. m6A modification of mRNA has been linked to cell proliferation, tumor progression and other biological events. However, how PIGT is regulated and what is the function of PIGT in bladder cancer remains to be elucidated.
METHODS: PIGT was silenced or overexpressed to study its role in regulating bladder cancer. Cell proliferation and invasion were examined with the Cell Counting Kit-8, colony formation and Transwell assay, respectively. Cellular oxygen consumption rates or extracellular acidification rates were detected by a XF24 Analyzer. Quantitative RT-PCR and immunoblots were performed to detect mRNA and protein levels.
RESULTS: PIGT was overexpressed in bladder cancer. Silencing PIGT inhibited cell proliferation, oxidative phosphorylation, and glycolysis. Overexpressing PIGT promoted cell proliferation, oxidative phosphorylation, glycolysis in vitro and tumor metastasis in vivo by activating glucose transporter 1 (GLUT1). PIGT also promoted GLUT1 glycosylation and membrane trafficking. Wilms' tumor 1-associated protein (WTAP) mediated PIGT m6A modification, and m6A reader, insulin-like growth factor 2 mRNA-binding protein (IGF2BP2), binds to the methylated PIGT to promote the stability of PIGT, leading to up-regulation of PIGT.
CONCLUSION: WTAP mediates PIGT m6A modification to increase the stability of PIGT via the IGF2BP2, which enhances cell proliferation, glycolysis, and metastasis in bladder cancer by modulating GLUT1 glycosylation and membrane trafficking.

Keywords:  Bladder cancer; Glucose transporter 1; Glycolysis; RNA methylation; phosphatidylinositol Glycan Anchor Biosynthesis Class T

DOI:  https://doi.org/10.1186/s12967-023-04805-0
Eur J Med Res. 2024 Jan 03. 29(1): 19

Exploring the prognostic potential of m6A methylation regulators in low-grade glioma: implications for tumor microenvironment modulation.

Honggang Wu, Siqi Chen, Ziliang Hu, Rong Ge, Lu Ma, Chao You, Yi Huang.

   BACKGROUND: The biological behavior of low-grade glioma (LGG) is significantly affected by N6-methyladenosine (m6A) methylation, an essential epigenetic alteration. Therefore, it is crucial to create a prognostic model for LGG by utilizing genes that regulate m6A methylation.
METHODS: Using TCGA and GTEx databases. We examined m6A modulator levels in LGG and normal tissues, and investigated PD-L1 and PD-1 expression, immune scores, immune cell infiltration, tumor immune microenvironment (TIME) and potential underlying mechanisms in different LGG clusters. We also performed immunohistochemistry and RT-qPCR to identify essential m6A adjustment factor.
RESULTS: The results showed that m6A regulatory element expression was significantly increased in LGG tissues and was significantly associated with TMIE. A substantial increase in PD-L1 and PD-1 levels in LGG tissues and high-risk cohorts was observed. PD-L1 expression was positively correlated with FTO, ZCCHC4, and HNRNPD, whereas PD-1 expression was negatively correlated with FTO, ZC3H7B, and HNRNPD. The prognostic signature created using regulators of m6A RNA methylation was shown to be strongly associated with the overall survival of LGG patients, and FTO and ZCCHC4 were confirmed as independent prognostic markers by clinical samples. Furthermore, the results revealed different TIME characteristics between the two groups of patients, indicating disrupted signaling pathways associated with LGG.
CONCLUSION: Our results present that the m6A regulators play vital role in regulating PD-L1/PD-1 expression and the infiltration of immune cells, thereby exerting a sizable impact on the TIME of LGG. Therefore, m6A regulators have precise predictive value in the prognosis of LGG.

Keywords:  Immune infiltrates; Low-grade glioma; N6-methyladenosine methylation; PD-1; PD-L1

DOI:  https://doi.org/10.1186/s40001-023-01621-6
Biomed Pharmacother. 2023 Dec 28. pii: S0753-3322(23)01864-4. [Epub ahead of print]170 116066

Emerging roles and mechanism of m6A methylation in rheumatoid arthritis.

Yayun Xu, Wenqiang Liu, Lijie Ren.

  Rheumatoid arthritis (RA) is a multifaceted autoimmune disease characterized by systemic inflammation, affecting both articular and extra-articular structures. This condition results in inflammation of joints and synovial membranes, accompanied by the development of systemic comorbidities. Despite extensive research, the precise pathogenic mechanisms responsible for RA have yet to be completely understood. RNA methylation, a burgeoning epigenetic alteration, assumes a pivotal function in the regulation of a myriad of biological phenomena, encompassing immunity, DNA damage response, tumorigenesis, metastasis, stem cell renewal, adipocyte differentiation, circadian rhythms, cellular development and differentiation, and cell division. The N6-methyladenosine (m6A) modification is the most prevalent among the various RNA modifications found in mammalian mRNA. Recent studies have provided evidence of the significant role played by m6A modification in the pathophysiological progression of RA. This review aims to provide a comprehensive analysis of the progress made in research focused on m6A modification in the context of RA, consolidate the underlying mechanisms involved in m6A modification during the initiation of RA and discuss the potential of targeting m6A modification as a viable therapeutic approach for RA.

Keywords:  M6A modification; Mechanism; Methylation-related enzymes; Pathogenesis; Rheumatoid arthritis; Therapeutic target

DOI:  https://doi.org/10.1016/j.biopha.2023.116066
Exp Mol Med. 2024 Jan 04.

WTAP-mediated m6A modification of FRZB triggers the inflammatory response via the Wnt signaling pathway in osteoarthritis.

Xueying An, Rongliang Wang, Zhongyang Lv, Wenshu Wu, Ziying Sun, Rui Wu, Wenjin Yan, Qing Jiang, Xingquan Xu.

Osteoarthritis (OA) is the most common form of arthritis. However, the exact pathogenesis remains unclear. Emerging evidence shows that N6-methyladenosine (m6A) modification may have an important role in OA pathogenesis. This study aimed to investigate the role of m6A writers and the underlying mechanisms in osteoarthritic cartilage. Among m6A methyltransferases, Wilms tumor 1-associated protein (WTAP) expression most significantly differed in clinical osteoarthritic cartilage. WTAP regulated extracellular matrix (ECM) degradation, inflammation and antioxidation in human chondrocytes. Mechanistically, the m6A modification and relative downstream targets in osteoarthritic cartilage were assessed by methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing, which indicated that the expression of frizzled-related protein (FRZB), a secreted Wnt antagonist, was abnormally decreased and accompanied by high m6A modification in osteoarthritic cartilage. In vitro dysregulated WTAP had positive effects on β-catenin expression by targeting FRZB, which finally contributed to the cartilage injury phenotype in chondrocytes. Intra-articular injection of adeno-associated virus-WTAP alleviated OA progression in a mouse model, while this protective effect could be reversed by the application of a Wnt/β-catenin activator. In summary, this study revealed that WTAP-dependent RNA m6A modification contributed to Wnt/β-catenin pathway activation and OA progression through post-transcriptional regulation of FRZB mRNA, thus providing a potentially effective therapeutic strategy for OA treatment.

DOI: https://doi.org/10.1038/s12276-023-01135-5
J Orthop Surg Res. 2024 Jan 04. 19(1): 33

m6A-modified circARHGAP12 promotes the aerobic glycolysis of doxorubicin-resistance osteosarcoma by targeting c-Myc.

Dawei Zhang, Qingzhu Guo, Kemin You, Yi Zhang, Yao Zheng, Tao Wei.

  Chemotherapy resistance accompanied by energy metabolism abnormality functions as one of the main reasons for treatment failure and poor prognosis. However, the function of N6-methyladenosine (m6A)-modified circular RNA (circRNA) on osteosarcoma (OS) is still unclear. Here, present research investigated the potential role and mechanism of circARHGAP12 on OS doxorubicin (Dox) resistance and aerobic glycolysis. Results indicated that circARHGAP12 was a novel m6A-modified circRNA, which was up-regulated in OS cells. Overexpression of circARHGAP12 promoted the Dox resistance half-maximal inhibitory concentration (IC50) and aerobic glycolysis (glucose uptake, lactate and ATP production) in OS cells (Saos-2/Dox, MG63/Dox). Mechanistically, m6A-modified circARHGAP12 could bind with c-Myc mRNA through m6A-dependent manner, thereby enhancing the c-Myc mRNA stability. Thus, these findings revealed the critical function of circARHGAP12 on OS Dox-resistance and aerobic glycolysis. Taken together, our study demonstrated a critical function of circARHGAP12 on OS chemotherapy resistance and energy metabolism abnormality, providing critical roles on OS treatment.

Keywords:  Aerobic glycolysis; Doxorubicin; Osteosarcoma; c-Myc; circARHGAP12

DOI:  https://doi.org/10.1186/s13018-023-04502-0
BMC Cancer. 2024 Jan 02. 24(1): 8

The role of the methyltransferase METTL3 in prostate cancer: a potential therapeutic target.

Xuming Zhou, Keqiang Chai, Hezhen Zhu, Cong Luo, Xiaofeng Zou, Junrong Zou, Guoxi Zhang.

  The incidence of prostate cancer (PCa), the most prevalent malignancy, is currently at the forefront. RNA modification is a subfield of the booming field of epigenetics. To date, more than 170 types of RNA modifications have been described, and N6-methyladenosine (m6A) is the most abundant and well-characterized internal modification of mRNAs involved in various aspects of cancer progression. METTL3, the first identified key methyltransferase, regulates human mRNA and non-coding RNA expression in an m6A-dependent manner. This review elucidates the biological function and role of METTL3 in PCa and discusses the implications of METTL3 as a potential therapeutic target for future research directions and clinical applications.

Keywords:  Biomarker; Drug-resistance; METTL3; Prostate cancer; m6A

DOI:  https://doi.org/10.1186/s12885-023-11741-1
J Genet Genomics. 2023 Dec 27. pii: S1673-8527(23)00259-X. [Epub ahead of print]

The m6A reader YTHDC2 maintains visual function and retinal photoreceptor survival through modulating translation of PPEF2 and PDE6B.

Yeming Yang, Xiaoyan Jiang, Junyao Chen, Lu Liu, Guo Liu, Kuanxiang Sun, Wenjing Liu, Xianjun Zhu, Qiuyue Guan.

  Inherited retinal dystrophies (IRDs) are major causes of visual impairment and irreversible blindness worldwide, while the precise molecular and genetic mechanisms are still unexclusive. N6-methyladenosine (m6A) modification is the most prevalent internal modification in eukaryotic mRNA. YTH domain containing 2 (YTHDC2), an m6A reader protein, has recently been identified as a key player in germline development and human cancer. However, its contribution to retinal function remains unknown. Here, we explore the role of YTHDC2 in visual function of retinal rod photoreceptors by generating rod-specific Ythdc2 knockout mice. Results show that Ythdc2 deficiency in rods causes diminished scotopic ERG responses and progressive retinal degeneration. Multi-omics analysis further identifies Ppef2 and Pde6b as the potential targets of YTHDC2 in the retina. Specifically, via its YTH domain, YTHDC2 recognizes and binds m6A-modified Ppef2 mRNA at the coding sequence and Pde6b mRNA at the 5'-UTR, resulting in enhanced translation efficiency without affecting mRNA levels. Compromised translation efficiency of Ppef2 and Pde6b after YTHDC2 depletion ultimately leads to decreased protein levels in the retina, impaired retinal function, and progressive rod death. Collectively, our finding highlights the importance of YTHDC2 in visual function and photoreceptor survival, which provides an unreported elucidation of IRD pathogenesis via epitranscriptomics.

Keywords:  Epitranscriptomics; Inherited retinal dystrophies; N(6)-methyladenosine (m(6)A); Photoreceptor degeneration; Retina function; YTHDC2

DOI:  https://doi.org/10.1016/j.jgg.2023.12.007
EMBO Rep. 2024 Jan 05.

DDX5 inhibits inflammation by modulating m6A levels of TLR2/4 transcripts during bacterial infection.

Jian Xu, Li-Yuan Liu, Fei-Jie Zhi, Yin-Juan Song, Zi-Hui Zhang, Bin Li, Fu-Ying Zheng, Peng-Cheng Gao, Su-Zi Zhang, Yu-Yu Zhang, Ying Zhang, Ying Qiu, Bo Jiang, Yong-Qing Li, Chen Peng, Yue-Feng Chu.

  DExD/H-box helicases are crucial regulators of RNA metabolism and antiviral innate immune responses; however, their role in bacteria-induced inflammation remains unclear. Here, we report that DDX5 interacts with METTL3 and METTL14 to form an m6A writing complex, which adds N6-methyladenosine to transcripts of toll-like receptor (TLR) 2 and TLR4, promoting their decay via YTHDF2-mediated RNA degradation, resulting in reduced expression of TLR2/4. Upon bacterial infection, DDX5 is recruited to Hrd1 at the endoplasmic reticulum in an MyD88-dependent manner and is degraded by the ubiquitin-proteasome pathway. This process disrupts the DDX5 m6A writing complex and halts m6A modification as well as degradation of TLR2/4 mRNAs, thereby promoting the expression of TLR2 and TLR4 and downstream NF-κB activation. The role of DDX5 in regulating inflammation is also validated in vivo, as DDX5- and METTL3-KO mice exhibit enhanced expression of inflammatory cytokines. Our findings show that DDX5 acts as a molecular switch to regulate inflammation during bacterial infection and shed light on mechanisms of quiescent inflammation during homeostasis.

Keywords:  Bacterial Infection; DDX5; Inflammation; N6-Methyladenosine; TLR2/4 Transcripts

DOI:  https://doi.org/10.1038/s44319-023-00047-9
Mol Cancer Res. 2024 Jan 05.

LRRC75A-AS1 drives the epithelial-mesenchymal transition in cervical cancer by binding IGF2BP1 and inhibiting SYVN1-mediated NLRP3 ubiquitination.

Hongying Sui, Caixia Shi, Zhipeng Yan, Jinyang Chen, Lin Man, Fang Wang.

Cervical cancer severely affects women's health with increased incidence and poor survival for patients with metastasis. Our study aims to investigate the mechanism by which lncRNA LRRC75A-AS1 regulates the epithelial-mesenchymal transition (EMT) of cervical cancer through modulating m6A and ubiquitination modification. In this study, tumor tissues were collected from patients to analyze the expression of LRRC75A-AS1 and SYVN1. Migratory and invasive capacities of HeLa and CaSki cells were evaluated with wound healing and transwell assays. CCK-8 and EdU incorporation assays were employed to examine cell proliferation. The interaction between LRRC75A-AS1, IGF2BP1, SYVN1, and NLRP3 was evaluated through RNA immunoprecipitation, RNA pull-down, FISH, and Co-IP assays, respectively. MeRIP-qPCR was applied to analyze the m6A modification of SYVN1 mRNA. A subcutaneous tumor model of cervical cancer was established. We showed LRRC75A-AS1 was upregulated in tumor tissues, and LRRC75A-AS1 enhanced EMT through activating NLRP3/IL-1β/Smad2/3 signaling in cervical cancer. Furthermore, LRRC75A-AS1 inhibited SYVN1-mediated NLRP3 ubiquitination by destabilizing SYVN1 mRNA. LRRC75A-AS1 competitively bound to IGF2BP1 protein and subsequently impaired the m6A modification of SYVN1 mRNA and its stability. Knockdown of LRRC75A-AS1 repressed EMT and tumor growth via inhibiting NLRP3/IL-1β/Smad2/3 signaling in mice. In conclusion, LRRC75A-AS1 competitively binds to IGF2BP1 protein to destabilize SYVN1 mRNA, subsequently suppresses SYVN1-mediated NLRP3 ubiquitination degradation and activates IL-1β/Smad2/3 signaling, thus promoting EMT in cervical cancer. Implications: LRRC75A-AS1 promotes cervical cancer progression, and this study suggests LRRC75A-AS1 as a new therapeutic target for cervical cancer.

DOI: https://doi.org/10.1158/1541-7786.MCR-23-0478
Heliyon. 2024 Jan 15. 10(1): e23204

Comprehensive analysis of m6A reader YTHDF2 prognosis, immune infiltration, and related regulatory networks in hepatocellular carcinoma.

Hang Wang, Hui Cai, Li Li.

   Background: N6-Methyladenosine (m6A) RNA modification is the most prevalent internal modification pattern in eukaryotic mRNAs and plays critical roles in diverse physiological and pathological processes. However, the expression of m6A regulator YTHDF2, its prognostic value, its biological function, its correlation with tumor microenvironment (TME) immune infiltrates, and related regulatory networks in hepatocellular carcinoma (HCC) remain determined.
Methods: TCGA, GTEx, and GEO databases were used to investigate the expression profile of YTHDF2 in HCC. We performed differentially expressed genes (DEGs) analysis and constructed a PPI network to explore the biological processes of YTHDF2 in HCC. Kaplan-Meier curves and Cox regression analysis were used to assess the prognostic value of YTHDF2 and then a clinical prognostic nomogram was constructed. Additionally, ssGSEA was performed to assess the correlation between YTHDF2 and immune infiltration levels. The TISIDB database was applied to explore the expression of YTHDF2 in immune and molecular subtypes of HCC. GSEA identifies the YTHDF2-related signaling pathways. Finally, we utilized miRNet and starBase database to construct regulatory networks for HCC based on lncRNA-miRNA and miRNA-YTHDF2 interactions.
Results: YTHDF2 was significantly upregulated in HCC tumor tissues compared with the adjacent normal tissues. HCC patients in the high YTHDF2 expression group had poorer survival. Multivariate Cox analysis suggested that YTHDF2 may be a new independent prognostic indicator for HCC patients, with the prognostic nomogram exhibiting satisfactory results. YTHDF2 expression was significantly correlated with TME immune cell-infiltrating characteristics. Strong correlations were also shown in immune subtypes, molecular subtypes and immune checkpoints. Further analysis revealed that the combination of YTHDF2 expression and immune cell score was considerably associated with survival outcome in HCC patients. GESA analysis demonstrated that high YTHDF2 expression is associated with multiple biological processes and oncogenic pathways. Moreover, 14 possible regulatory networks were constructed, which are associated with HCC progression.
Conclusion: Our findings revealed that YTHDF2 may serve as a promising prognostic biomarker for HCC and may regulate the tumor immune microenvironment to provide effective therapeutic strategies.

Keywords:  Epitranscriptomics; Hepatocellular carcinoma; Immune infiltration; Prognostic signature; m6A methylation

DOI:  https://doi.org/10.1016/j.heliyon.2023.e23204
J Physiol Biochem. 2023 Dec 30.

N6-methyladenosine in myeloid cells: a novel regulatory factor for inflammation-related diseases.

Jin Pang, Tong-Dong Kuang, Xin-Yuan Yu, Petr Novák, Yuan Long, Min Liu, Wei-Qian Deng, Xiao Zhu, Kai Yin.

  N6-methyladenosine (m6A) is one of the most abundant epitranscriptomic modifications on eukaryotic mRNA. Evidence has highlighted that m6A is altered in response to inflammation-related factors and it is closely associated with various inflammation-related diseases. Multiple subpopulations of myeloid cells, such as macrophages, dendritic cells, and granulocytes, are crucial for the regulating of immune process in inflammation-related diseases. Recent studies have revealed that m6A plays an important regulatory role in the functional of multiple myeloid cells. In this review, we comprehensively summarize the function of m6A modification in myeloid cells from the perspective of myeloid cell production, activation, polarization, and migration. Furthermore, we discuss how m6A-mediated myeloid cell function affects the progression of inflammation-related diseases, including autoimmune diseases, chronic metabolic diseases, and malignant tumors. Finally, we discuss the challenges encountered in the study of m6A in myeloid cells, intended to provide a new direction for the study of the pathogenesis of inflammation-related diseases.

Keywords:  Inflammation-related diseases; Myeloid cells; N6-methyladenosine

DOI:  https://doi.org/10.1007/s13105-023-01002-x
STAR Protoc. 2024 Jan 04. pii: S2666-1667(23)00782-7. [Epub ahead of print]5(1): 102815

Protocol to analyze the role of various metabolites in impacting global RNA 5-methylcytosine levels in cultured cells by dot blot.

Tingjin Chen, Hui-Kuan Lin.

  RNA 5-methylcytosine (m5C) modification critically impacts many biological processes. Here, we provide a protocol to analyze the role of various metabolites in impacting global RNA m5C levels in cultured cells by dot blot. We describe steps for treating cultured cells with various metabolites; extracting, quantifying, and denaturing RNA samples; and performing dot blot to detect global RNA m5C levels in cultured cells. We then detail procedures to verify the input loading by methylene blue staining and quantify using ImageJ. For complete details on the use and execution of this protocol, please refer to Chen et al.1.

Keywords:  Cancer; Metabolism

DOI:  https://doi.org/10.1016/j.xpro.2023.102815
Cell Biol Int. 2024 Jan 02.

N6 methyladenosine eraser FTO suppresses Staphylococcus aureus-induced ferroptosis of bone marrow mesenchymal stem cells to ameliorate osteomyelitis through regulating the MDM2/TLR4/SLC7A11 signaling pathway.

Muguo Song, Kehan Lv, Zhi Xu, Junyi Li, Jian Sun, Jian Shi, Yongqing Xu.

  Osteomyelitis is a bone destructive inflammatory disease caused by infection. Ferroptosis is closely related to multiple inflammatory diseases, but the role of ferroptosis in Staphylococcus aureus (SA)-induced osteomyelitis remains unknown. In the present study, we found that SA treatment promoted the accumulation of iron, Fe2+ , lipid peroxide, and malondialdehyde, increased TFRC and reduced FTH1 and GPX4 to trigger ferroptosis in rat bone marrow mesenchymal stem cells (BMSCs). Interestingly, increased level of N6 methyl adenosine (m6A) modification along with decreased expression level of m6A eraser FTO were observed in SA-induced BMSCs, while upregulating FTO alleviated SA-triggered ferroptosis and protected cell viability in BMSCs. Mechanistically, MDM2 was identified as a target of FTO-mediated m6A demethylation, and FTO upregulation promoted MDM2 instability to downregulated TLR4 signal and elevate the expression of SLC7A11 and GPX4 in SA-induced BMSCs. Functional recovery experiments verified that overexpressing MDM2 or TLR4 reversed the inhibiting effect of FTO upregulation on ferroptosis in SA-treated BMSCs. Additionally, FTO upregulation restrained ferroptosis and pathological damage to bone tissue in SA-induced osteomyelitis model rats. Altogether, m6A eraser FTO alleviates SA-induced ferroptosis in osteomyelitis models partly through inhibiting the MDM2-TLR4 axis.

Keywords:  FTO; MDM2; N6 methyladenosine; Staphylococcus aureus; ferroptosis; osteomyelitis

DOI:  https://doi.org/10.1002/cbin.12115
EMBO J. 2024 Jan;43(1): 61-86

YTHDC1 delays cellular senescence and pulmonary fibrosis by activating ATR in an m6A-independent manner.

Canfeng Zhang, Liping Chen, Chen Xie, Fengwei Wang, Juan Wang, Haoxian Zhou, Qianyi Liu, Zhuo Zeng, Na Li, Junjiu Huang, Yong Zhao, Haiying Liu.

  Accumulation of DNA damage in the lung induces cellular senescence and promotes age-related diseases such as idiopathic pulmonary fibrosis (IPF). Hence, understanding the mechanistic regulation of DNA damage repair is important for anti-aging therapies and disease control. Here, we identified an m6A-independent role of the RNA-binding protein YTHDC1 in counteracting stress-induced pulmonary senescence and fibrosis. YTHDC1 is primarily expressed in pulmonary alveolar epithelial type 2 (AECII) cells and its AECII expression is significantly decreased in AECIIs during fibrosis. Exogenous overexpression of YTHDC1 alleviates pulmonary senescence and fibrosis independent of its m6A-binding ability, while YTHDC1 deletion enhances disease progression in mice. Mechanistically, YTHDC1 promotes the interaction between TopBP1 and MRE11, thereby activating ATR and facilitating DNA damage repair. These findings reveal a noncanonical function of YTHDC1 in delaying cellular senescence, and suggest that enhancing YTHDC1 expression in the lung could be an effective treatment strategy for pulmonary fibrosis.

Keywords:  ATR; IPF; Senescence; YTHDC1

DOI:  https://doi.org/10.1038/s44318-023-00003-2
Nucleic Acids Res. 2024 Jan 05. pii: gkad1242. [Epub ahead of print]

METTL3 drives telomere targeting of TERRA lncRNA through m6A-dependent R-loop formation: a therapeutic target for ALT-positive neuroblastoma.

Roshan Vaid, Ketan Thombare, Akram Mendez, Rebeca Burgos-Panadero, Anna Djos, Daniel Jachimowicz, Kristina Ihrmark Lundberg, Christoph Bartenhagen, Navinder Kumar, Conny Tümmler, Carina Sihlbom, Susanne Fransson, John Inge Johnsen, Per Kogner, Tommy Martinsson, Matthias Fischer, Tanmoy Mondal.

Telomerase-negative tumors maintain telomere length by alternative lengthening of telomeres (ALT), but the underlying mechanism behind ALT remains poorly understood. A proportion of aggressive neuroblastoma (NB), particularly relapsed tumors, are positive for ALT (ALT+), suggesting that a better dissection of the ALT mechanism could lead to novel therapeutic opportunities. TERRA, a long non-coding RNA (lncRNA) derived from telomere ends, localizes to telomeres in a R-loop-dependent manner and plays a crucial role in telomere maintenance. Here we present evidence that RNA modification at the N6 position of internal adenosine (m6A) in TERRA by the methyltransferase METTL3 is essential for telomere maintenance in ALT+ cells, and the loss of TERRA m6A/METTL3 results in telomere damage. We observed that m6A modification is abundant in R-loop enriched TERRA, and the m6A-mediated recruitment of hnRNPA2B1 to TERRA is critical for R-loop formation. Our findings suggest that m6A drives telomere targeting of TERRA via R-loops, and this m6A-mediated R-loop formation could be a widespread mechanism employed by other chromatin-interacting lncRNAs. Furthermore, treatment of ALT+ NB cells with a METTL3 inhibitor resulted in compromised telomere targeting of TERRA and accumulation of DNA damage at telomeres, indicating that METTL3 inhibition may represent a therapeutic approach for ALT+ NB.

DOI: https://doi.org/10.1093/nar/gkad1242
Cell Chem Biol. 2023 Dec 21. pii: S2451-9456(23)00434-8. [Epub ahead of print]

Modifying the antiviral innate immune response by selective writing, erasing, and reading of m6A on viral and cellular RNA.

Caroline J Aufgebauer, Katherine M Bland, Stacy M Horner.

  Viral infection and the antiviral innate immune response are regulated by the RNA modification m6A. m6A directs nearly all aspects of RNA metabolism by recruiting RNA-binding proteins that mediate the fate of m6A-containing RNA. m6A controls the antiviral innate immune response in diverse ways, including shielding viral RNA from detection by antiviral sensors and influencing the expression of cellular mRNAs encoding antiviral signaling proteins, cytokines, and effector proteins. While m6A and the m6A machinery are important for the antiviral response, the precise mechanisms that determine how the m6A machinery selects specific viral or cellular RNA molecules for modification during infection are not fully understood. In this review, we highlight recent findings that shed light on how viral infection redirects the m6A machinery during the antiviral response. A better understanding of m6A targeting during viral infection could lead to new immunomodulatory and therapeutic strategies against viral infection.

Keywords:  ALKBH5; FTO; METTL3; N6-methyladenosine; RIG-I; YTHDF; antiviral innate immunity; interferon

DOI:  https://doi.org/10.1016/j.chembiol.2023.12.004
Theranostics. 2024 ;14(2): 622-639

Pharmacological inhibition of MYC to mitigate chemoresistance in preclinical models of squamous cell carcinoma.

Shuo Liu, Zhen Qin, Yaqing Mao, Ning Wang, Wenbo Zhang, Yujia Wang, Yiwen Chen, Lingfei Jia, Xin Peng.

  Rationale: Cisplatin-based chemotherapy is the first-line treatment for late-stage head and neck squamous cell carcinoma (HNSCC). However, resistance to cisplatin has become a major obstacle for effective therapy. Cancer stem cells (CSCs) are critical for tumor initiation, growth, metastasis, and chemoresistance. How to effectively eliminate CSCs and overcome chemoresistance remains a key challenge. Herein, we confirmed that MYC plays critical roles in chemoresistance, and explored targeting MYC to overcome cisplatin resistance in preclinical models. Methods: The roles of MYC in HNSCC cisplatin resistance and cancer stemness were tested in vitro and in vivo. The combined therapeutic efficiency of MYC targeting using the small molecule MYC inhibitor MYCi975 and cisplatin was assessed in a 4‑nitroquinoline 1-oxide-induced model and in a patient-derived xenograft model. Results: MYC was highly-expressed in cisplatin-resistant HNSCC. Targeting MYC using MYCi975 eliminated CSCs, prevented metastasis, and overcame cisplatin resistance. MYCi975 also induced tumor cell-intrinsic immune responses, and promoted CD8+ T cell infiltration. Mechanistically, MYCi975 induced the DNA damage response and activated the cGAS-STING-IRF3 signaling pathway to increase CD8+ T cell-recruiting chemokines. Conclusions: Our findings suggested that targeting MYC might eliminate CSCs, prevent metastasis, and activate antitumor immunity to overcome cisplatin resistance in HNSCC.

Keywords:  Cancer stem cells; Cisplatin resistance; DNA damage response; Head and neck squamous cell carcinoma; MYC

DOI:  https://doi.org/10.7150/thno.88759
J Virol. 2024 Jan 03. e0135023

N-acetyltransferase 10 regulates alphavirus replication via N4-acetylcytidine (ac4C) modiﬁcation of the lymphocyte antigen six family member E (LY6E) mRNA.

Yamei Dang, Jia Li, Yuchang Li, Yuan Wang, Yajing Zhao, Ningbo Zhao, Wanying Li, Hui Zhang, Chuantao Ye, Hongwei Ma, Liang Zhang, He Liu, Yangchao Dong, Min Yao, Yingfeng Lei, Zhikai Xu, Fanglin Zhang, Wei Ye.

   IMPORTANCE: The role of N4-acetylcytidine (ac4C) modification in host mRNA and virus replication is not yet fully understood. In this study, the role of ac4C in the regulation of Sindbis virus (SINV), a prototype alphavirus infection, was investigated. SINV infection results in increased levels of N-acetyltransferase 10 (NAT10) and increases the ac4C modification level of cellular RNA. The NAT10 was found to positively regulate SINV infection in an N-acetyltransferase activity-dependent manner. Mechanistically, the NAT10 modifies lymphocyte antigen six family member E (LY6E) mRNA-the ac4C modification site within the 3'-untranslated region (UTR) of LY6E mRNA, which is essential for its translation and stability. The findings of this study demonstrate that NAT10 regulated mRNA stability and translation efficiency not only through the 5'-UTR or coding sequence but also via the 3'-UTR region. The ac4C modification of host mRNA stability instead of viral mRNA impacting the viral life cycle was thus identified, indicating that the inhibition of ac4C could be a potential target when developing alphavirus antivirals.

Keywords:  N-acetyltransferase 10 (NAT10); N4-acetylcytidine (ac4C); Sindbis virus (SINV); alphavirus; lymphocyte antigen 6 family member E (LY6E)

DOI:  https://doi.org/10.1128/jvi.01350-23