NAT10 promotes cell proliferation by acetylating CEP170 mRNA to enhance translation efficiency in multiple myeloma

Target inhibition of NAT10-mediated ac4C modification prevents seizure behavior in mice

N4-acetylation of Cytidine (ac4C), catalyzed by its only known enzyme N-acetyltransferase 10 (NAT10), facilitates cellular mRNA translation and stability, but its function in brain disorders especially epilepsy is poorly understood. By using pentylenetetrazole (PTZ) induced mouse model of epilepsy, we first displayed spatiotemporally expression of ac4C and NAT10 in the mouse brain. To corroborate the alteration of ac4C and NAT10 in epilepsy, we used acute PTZ, chronic PTZ and intrahippocampal kainic acid (IHKA) mouse model. We then utilized a combination of viral tool and pharmacological approaches to implicate NAT10 mediated ac4C modification in seizure behaviors. We found that the expression of ac4C was increased in epileptic brain tissues in mouse models of epilepsy, which might be due to the up-regulated NAT10. Block of NAT10 led to both reduced brain ac4C level and resistance to PTZ or KA-induced seizure behavior, while hippocampal over-expression of NAT10 causes exacerbated seizure behavior. In support of such a role, our data demonstrated that the loss or gains of ac4C modification could normalize or exacerbate neuronal over-activation in epileptic brain tissues, respectively. Mechanically, we observed that block the NAT10 or over-expression NAT10 lead to reduced or enhanced BDNF, respectively. While the BDNF pathway inhibitor rescued the hippocampal NAT10 over-expression induced aggravated seizure behavior in the chronic PTZ treated mice. Therefore, our work provides the first demonstration of the ac4C levels in an epilepsy mice model, targeted to prevent ac4C by NAT10 inhibition seems to be effective in preventing and treating epilepsy.

Key epigenetic enzymes modulated by natural compounds contributes to tumorigenicity

Dysregulation of epigenetic regulation is observed in numerous tumor cells. The therapeutic effects of natural products on tumors were investigated through a comprehensive analysis of active ingredients derived from various structured natural products. The analysis focuses on regulating key enzymes involved in epigenetic control. To study the modulation of these enzymes for tumor treatment, the structural characteristics of natural products that impact tumorigenesis were identified. The presence of specific patterns suggests that compounds sharing structural similarities can potentially induce therapeutic effects on identical tumors through modulation of distinct modifying enzymes. Structurally analogous natural products can likewise achieve therapeutic effects across diverse tumor types via their interaction with a common epigenetic enzyme. There exist numerous flavonoids with the capability to modulate METTL3, thereby influencing the development of various tumors. The normalization process was implemented to account for a common phenomenon, wherein structurally distinct compounds effectively target the same tumor by modulating a shared key enzyme. By summarizing, valuable insights into the role of compound-epigenetic enzymes in tumor development have been obtained. This discovery establishes a crucial scientific foundation for the prevention and treatment of tumor development through the utilization of structurally similar natural active ingredients.

Genomic characteristics and prognostic correlations in Chinese multiple myeloma patients

BACKGROUND

Multiple myeloma (MM) is a hematologic malignancy characterized by the proliferation of abnormal clonal plasma cells in the bone marrow. The heterogeneity in Chinese MM populations remains underexplored.

METHODS

We conducted whole-exome sequencing (WES) on 241 tumor samples, complemented by RNA sequencing (RNA-seq) on 131 samples from 212 Chinese MM patients.

RESULTS

We identified a novel mutational signature and analyzed molecular differences between newly diagnosed MM (NDMM) and relapsed/refractory MM (RRMM) patients. NFKBIA mutations were notably more frequent in NDMM patients compared to the MMRF-COMMPASS cohort (4/50 vs 22/937, p = 0.048), with additional recurrent mutations in several genes like TTN, IGLL5 and SYNE1. In RRMM patients, UBR5 mutations were more prevalent (4/24 vs 0/50, p = 0.01), alongside frequent mutations in OBSCN, CACNA1H, and HSPG2. Clonal evolution was assessed through multiple time points and locations, identifying genes potentially linked to circulating plasma cell formation. Cox regression analysis revealed that age and mutations in OBSCN and RB1 were significant predictors of progression-free survival (PFS) in NDMM patients. Additionally, albumin, β2-microglobulin, and RB1 mutations were correlated with overall survival (OS).

CONCLUSIONS

In summary, we characterized the genomic landscape of MM in diverse Chinese populations, confirmed clonal evolution, and identified prognostic genes.

N-Acetyltransferase 10 Promotes Gastric Cancer Progression by Mediating the N4-Acetylcytidine Modification of Lactate Dehydrogenase A

The N4-acetylcytidine (ac4C) modification, which is catalyzed by NAT10, represents a significant posttranscriptional modification of mRNA in multiple cancers. However, the significance of this modification in gastric cancer (GC) progression remains unclear. To evaluate the potential of differential NAT10 expression in GC, RT-qPCR and western blot were employed. Dot blot and acRIP were utilized for total ac4C and LDHA mRNA ac4C detection. Subsequently, the effects of NAT10 on GC cell viability and glycolysis were assessed by Cell Counting Kit-8 and glycolysis-related indicator detection Kits. Furthermore, rescue experiments and mice xenograft experiments were conducted to investigate the mechanism underlying the NAT10/LDHA signaling axis in GC. This study identified upregulated NAT10 and ac4C levels in GC. Knockdown of NAT10 led to inhibited cell viability and glycolysis. Additionally, NAT10 directly bound to LDHA mRNA. NAT10 silencing decreased the expression and stability of LDHA mRNA, as well as its ac4C modification level. Interestingly, LDHA overexpression partially reversed the effects of NAT10 knockdown on cell viability and glycolysis. Eventually, the oncogenic effect of NAT10/ac4C/LDHA axis was confirmed in xenograft experiments. NAT10 promoted the GC progression by mediating the ac4C modification of LDHA mRNA, which could serve as a potential therapeutic target for GC.

NAT10 induces mitochondrial dysfunction in lung epithelial cells by acetylating HMGB1 to exacerbate Pseudomonas aeruginosa-induced acute lung injury

BACKGROUND

Pseudomonas aeruginosa (PA) is a major pathogen that causes pneumonia and acute lung injury (ALI). Dysregulated NAT10 expression is associated with inflammatory and infectious diseases, but its role in PA-induced ALI remains unclear.

METHODS

A mouse pneumonia model was established by intratracheal injection of PA, and lentivirus-mediated NAT10 interference and HMGB1 overexpression vectors were administered via the tail vein. Lung mechanics, protein content, total cell counts, neutrophil counts, inflammatory factor levels in bronchoalveolar lavage fluid (BALF), and lung bacterial load were assessed 24 h after PA injection. HE staining was performed to evaluate lung structural damage. Intracellular oxidative stress levels in mouse lung epithelial cells (TC-1 cells) were measured by detecting ROS and MDA levels. Mitochondrial function was analyzed by testing the mitochondrial membrane potential, cytoplasmic accumulation of cytochrome C, mtDNA copy number, and ATP production. An N4-acetylcytidine (ac4C)-RNA immunoprecipitation assay was conducted to assess the ac4C level of HMGB1 mRNA.

RESULTS

NAT10 deficiency hindered PA infection-induced increases in immune cell infiltration, inflammatory factor levels, bacterial load, and ultimately lung structural and functional damage. However, upregulation of HMGB1 effectively antagonized the protective effects of NAT10 silencing in vivo. NAT10 knockdown suppressed PA-induced oxidative stress, mitochondrial dysfunction, and apoptosis in vitro. Whereas, HMGB1 overexpression reversed the inhibitory effects of NAT10 downregulation on PA-induced TC-1 cell injury. Mechanistically, as an acetyltransferase, NAT10 enhanced HMGB1 mRNA stability and protein expression by promoting HMGB1 mRNA ac4C modification.

CONCLUSION

NAT10 facilitated mitochondrial dysfunction in lung epithelial cells and exacerbated PA-induced ALI by promoting the N4-acetylcytidine of HMGB1 mRNA.

N-acetyltransferase 10 Promotes Cervical Cancer Progression Via N4-acetylation of SLC7A5 mRNA

INTRODUCTION

N-acetyltransferase 10 (NAT10) mediates N4-acetylcytidine (ac4C) mRNA modification and promotes malignant tumor progression. However, there has been limited research on its role in cervical cancer. This study aimed to decipher the role of NAT10 in cervical cancer.

METHODS

The prognostic value of NAT10 was explored using the cancer genome atlas (TCGA) database and immunohistochemistry of cervical cancer tissue. The biological actions of NAT10 in cervical cancer were investigated by cell proliferation, transwell, wound healing, and chicken chorioallantoic membrane assays. The therapeutic action of remodelin (a NAT10 inhibitor) was verified in a nude mouse model. Mechanistic analyses were conducted by RNA sequencing, ac4C dot blotting, acetylated RNA immunoprecipitation, quantitative PCR, and RNA stability experiments.

RESULTS

NAT10 was overexpressed in cervical carcinoma and its overexpression was associated with poor prognosis. NAT10 knockout impaired proliferative and metastatic potentials of cervical cancer cells, while its overexpression had the opposite effects. Remodelin impaired cervical cancer proliferation in vivo and in vitro. NAT10 acetylated solute carrier family 7 member 5 (SLC7A5) enhanced mRNA stability to regulate SLC7A5 expression.

CONCLUSIONS

NAT10 exerts a critical role in cervical cancer progression via acetylating SLC7A5 mRNA and could represent a key prognostic and therapeutic target in cervical cancer.

Acetyltransferase NAT10 promotes gastric cancer progression by regulating the Wnt/β-catenin signaling pathway and enhances chemotherapy resistance

BACKGROUND

N-acetyltransferase 10 (NAT10) is involved in several cellular processes. NAT10 expression is essential for the promotion of mRNA translation and stability.  In some situations, deregulation of NAT10 has been attributed to the development of multiple types of cancer. NAT10 is significantly upregulated in various gastrointestinal tumors, including esophageal, colorectal, pancreatic, and liver cancers, and is correlated with poor prognosis. Additionally, NAT10 expression contributes to chemotherapy resistance in both esophageal and colorectal cancers. Nevertheless, the role of NAT10 in gastric cancer (GC), a type of gastrointestinal tumor, is not fully understood.

METHODS

Throughout this investigation, our team evaluated NAT10 expression levels in GC patient samples and databases available to the general public. Based on the knockdown and overexpression of NAT10, in vitro experiments were conducted to examine the effects of NAT10 on GC progression and resistance to chemotherapy.

RESULTS

Our study demonstrated that GC tissues exhibit increased levels of NAT10. Downregulation of NAT10 decreased GC cell proliferation, migration, and invasiveness. Conversely, upregulation of NAT10 resulted in the opposite effect. Furthermore, NAT10 fosters the progression of GC cells by activating the Wnt/β-catenin signaling pathway. NAT10 also promotes resistance to cisplatin chemotherapy.

CONCLUSIONS

Our findings indicated that expression of NAT10 promoted GC progression through activation of the Wnt/β-catenin signaling pathway. We investigated the effect of NAT10 on the viability of GC cells treated with different doses of cisplatin. The results showed that NAT10 expression could impact the effectiveness of chemotherapy resistance in GC. This implies that using NAT10 as a target may be a potential therapeutic strategy for treating GC.

Biological function and mechanism of NAT10 in cancer

N-acetyltransferase 10 (NAT10) is a nucleolar acetyltransferase with an acetylation catalytic function and can bind various protein and RNA molecules. As the N4-acetylcytidine (ac4C) "writer" enzyme, NAT10 is reportedly involved in a variety of physiological and pathological activities. Currently, the NAT10-related molecular mechanisms in various cancers are not fully understood. In this review, we first describe the cellular localization of NAT10 and then summarize its numerous biological functions. NAT10 is involved in various biological processes by mediating the acetylation of different proteins and RNAs. These biological functions are also associated with cancer progression and patient prognosis. We also review the mechanisms by which NAT10 plays roles in various cancer types. NAT10 can affect tumor cell proliferation, metastasis, and stress tolerance through its acetyltransferase properties. Further research into NAT10 functions and expression regulation in tumors will help explore its future potential in cancer diagnosis, treatment, and prognosis.

The N-acetyltransferase 10 inhibitor [11C]remodelin: synthesis and preliminary positron emission tomography study in mice

BACKGROUND

4-(4-Cyanophenyl)-2-(2-cyclopentylidenehydrazinyl)thiazole (remodelin) is a potent N-acetyltransferase 10 (NAT10) inhibitor. This compound inhibits tumors and weakens tumor resistance to antitumor drugs. Moreover, remodelin has been found to enhance healthspan in an animal model of the human accelerated ageing syndrome. In this study, we synthesized C-11-labelled remodelin ([11C]remodelin) for the first time as a positron emission tomography (PET) probe and assessed its biodistribution in mice using PET.

RESULTS

[11C]Remodelin was synthesized by the reaction of a boron ester precursor (1) with hydrogen [11C]cyanide, which was prepared from the cyclotron-produced [11C]carbon dioxide via [11C]methane. The decay-corrected radiochemical yield of [11C]remodelin was 6.2 ± 2.3% (n = 20, based on [11C]carbon dioxide) with a synthesis time of 45 min and radiochemical purity of > 90%. A PET study with [11C]remodelin showed high uptake of radioactivity in the heart, liver, and small intestine of mice. The metabolite analysis indicated moderate metabolism of [11C]remodelin in the heart.

CONCLUSIONS

In the present study, we successfully synthesized [11C]remodelin and assessed its biodistribution of radioactivity in the mouse organs and tissues with PET. We are planning to prepare tumor and inflammatory models in which overexpression of NAT10 is possibly induced and conduct PET imaging for these animal models with [11C]remodelin to elucidate the relationship between NAT10 and diseases.

METTL3-mediated CEP170 m6A modifications in spindle orientation and esophageal cancer cell proliferation

Esophageal cancer is a major malignancy with a high incidence and poor prognosis. To elucidate the mechanisms underlying its progression, particularly with respect to cell division and spindle orientation, we investigated the role of m6A modifications and the centrosomal protein CEP170. Using m6A-seq and RNA-seq of esophageal cancer tissues and adjacent normal tissues, we identified significant alterations in m6A modifications and gene expression, highlighting the upregulation and m6A enrichment of CEP170 in tumor tissues. Functional assays, including cell cycle synchronization, qPCR, immunoblotting, immunofluorescence, coimmunoprecipitation, methylated RNA immunoprecipitation, and cell proliferation assays, demonstrated that CEP170 plays a critical role in mitotic progression and spindle orientation. m6A-seq and RNA-seq revealed significant alterations in m6A modifications and gene expression in esophageal cancer. CEP170 was upregulated and highly enriched in m6A modifications in tumor tissues. Functional assays revealed that CEP170 plays a critical role in proper mitotic progression and spindle orientation. Knockdown of CEP170 led to spindle misorientation and impaired the stability of astral microtubules. Additionally, CEP170 affected the localization of the dynein/dynactin motor complex in the cell cortex. METTL3 was upregulated in tumor tissues and regulated CEP170 expression. RNA-seq upon CEP170 depletion revealed that ASPM was significantly downregulated, indicating its involvement as a downstream target of CEP170 in regulating cell proliferation and mitosis. Our findings provide novel insights into the molecular mechanisms by which CEP170 and m6A modifications regulate esophageal cancer progression, revealing that CEP170 is a potential therapeutic target.

The RNA-binding protein CMSS1 promotes the progression of non-small cell lung cancer by regulating the telomerase protein subunit hTERT

AIMS

High telomerase activity has been detected in over 85 % of tumors, with the activation of hTERT being the most crucial mechanism for re-establishing telomerase activity. Activation of hTERT maintains telomere length in cells, enabling cancer cells to proliferate indefinitely. Nevertheless, the specific mechanism of telomerase activation in non-small cell lung cancer (NSCLC) remains unclear, and post-transcriptional regulation of hTERT could be a potential activation mechanism.

MATERIALS AND METHODS

We explored the regulatory impact of CMSS1 on hTERT expression in NSCLC cells using several methods: Yeast three-hybrid system, Reporter gene assay, Western blot, RNA decay assay, and Telomere length measurement. Our analysis revealed significant overexpression of CMSS1 in NSCLC, which correlated with poor prognosis, as determined by bioinformatics and tissue microarray techniques. RNA sequencing analysis showed that CMSS1 knockdown influenced the adhesion capabilities of NSCLC cells. Additionally, potential interacting proteins with CMSS1 were identified through mass spectrometry and co-immunoprecipitation experiments.

KEY FINDINGS

We discovered that CMSS1 regulates hTERT expression in NSCLC cells by binding to the 5' UTR of hTERT mRNA, impacting its mRNA stability and thereby influencing NSCLC progression. RNA-Seq results and adhesion experiments indicated that CMSS1 knockdown disrupts cell adhesion. hTERT also affects cell adhesion in NSCLC, underscoring CMSS1's role as an upstream regulator of hTERT. Mass spectrometry and Co-IP studies suggest potential interactions between CMSS1, RBM34, and DDX5 that further modulate hTERT expression.

SIGNIFICANCE

These findings indicate that CMSS1 plays a crucial role in NSCLC progression through its interaction with hTERT, making it a promising therapeutic target.

Advances of NAT10 in diseases: insights from dual properties as protein and RNA acetyltransferase

N-acetyltransferase 10 (NAT10) is a member of the Gcn5-related N-acetyltransferase (GNAT) family and it plays a crucial role in various cellular processes, such as regulation of cell mitosis, post-DNA damage response, autophagy and apoptosis regulation, ribosome biogenesis, RNA modification, and other related pathways through its intrinsic protein acetyltransferase and RNA acetyltransferase activities. Moreover, NAT10 is closely associated with the pathogenesis of tumors, Hutchinson-Gilford progeria syndrome (HGPS), systemic lupus erythematosus, pulmonary fibrosis, depression and host-pathogen interactions. In recent years, mRNA acetylation has emerged as a prominent focus of research due to its pivotal role in regulating RNA stability and translation. NAT10 stands out as the sole identified modification enzyme responsible for RNA acetylation. There remains some ambiguity regarding the similarities and differences in NAT10's actions on protein and RNA substrates. While NAT10 involves acetylation modification in both cases, which is a crucial molecular mechanism in epigenetic regulation, there are significant disparities in the catalytic mechanisms, regulatory pathways, and biological processes involved. Therefore, this review aims to offer a comprehensive overview of NAT10 as a protein and RNA acetyltransferase, covering its basic catalytic features, biological functions, and roles in related diseases.

N-acetyltransferase 10 regulates UNC-51-like kinase 1 to reduce tubular cell injury and kidney stone formation

Objective

Among the most common chronic kidney diseases, kidney stones are second only to hypertension. Kidney stones pose a public health threat due to their increased incidence, high recurrence rate, and heavy economic burden. In this work, we investigated the potential mechanism of N-acetyltransferase 10 (NAT10) in oxidative stress and pyroptosis of renal tubular epithelial cells (RTECs).

Material and Methods

A kidney-stone cell model was simulated using calcium oxalate monohydrate (COM) in vitro. Western blot analysis of NAT10 expression and N4-acetylcytidine RNA immunoprecipitation verified the regulatory efficacy of NAT10 in Unc-51 like autophagy activating kinase 1 (ULK1) ac4C modification. The luciferase reporter gene assay further verified the interaction between NAT10 and ULK1. A kidney stone model was established using BALB/c mice injected with glyoxylic acid.

Results

COM can dose-dependently suppressed the cell viability and superoxide dismutase activity of HK-2 cells and promoted the release of lactate dehydrogenase and malondialdehyde levels (P < 0.05). COM also promoted apoptosis in HK-2 cells, upregulated the protein levels of caspase-1 and gasdermin D-N, and simultaneously enhanced the HK-2 cell secretion of interleukin-1b (IL-1b) and IL-18 (P < 0.05). The overexpression of NAT10 in HK-2 cells reversed the aforementioned effects, and that of NAT10 upregulated the messenger RNA (mRNA) levels of ULK1 and increased ac4C modification (P < 0.01). Furthermore, only the luciferase activity of the wild-type ULK1 containing NAT10 binding sites was enhanced with the upregulation of NAT10 (P < 0.001). Actinomycin D treatment showed that NAT10 overexpression extended the half-life of ULK1 mRNA (P < 0.01). Silencing of ULK1 neutralized the effects of NAT10 overexpression on COM-induced cell injury (P < 0.05). In addition, the increased expression of NAT10 inhibited crystal deposition, oxidative stress, and apoptosis in vivo (P < 0.05).

Conclusion

This study confirmed that NAT10 inhibits RTECs oxidative stress and cell pyrodeath through the enhanced ac4C modification of ULK1 and impedes kidney stone progression.

Compression force promotes the osteogenic differentiation of periodontal ligament stem cells by regulating NAT10-mediated ac4C modification of BMP2

BACKGROUND

Orthodontic treatment applies specific corrective forces to teeth, transmitting stress to periodontal tissue, thereby regulating the growth and development of periodontal ligament stem cells (PDLSCs). Recently, N-acetyltransferase 10 (NAT10) mediated N4-acetylcytidine (ac4C) modification is demonstrated to play a key role in the osteogenic differentiation of stem cells. Therefore, this study aimed explore the effects of Orthodontic treatment on the NAT10 mediated ac4C modification and osteogenic differentiation of PDLSCs.

METHODS

Compressive force was used to treat PDLSCs to simulate orthodontic force treatment. The ALP and ARS staining was performed to analyze the osteogenic differentiation of PDLSCs. Besides, ac4C dot blot and ac4C-RIP assays were performed to detect the global ac4C levels and BMP2 ac4C levels. The relationship between NAT10 and BMP2 was confirmed by RIP assay and immunofluorescence staining. The mRNA and protein levels of RUNX2, Oxterix and BMP2 were detected by RT-qPCR and western blot assays.

RESULTS

Compressive force treatment promoted the osteogenic differentiation of PDLSCs, and enhanced the global ac4C levels and NAT10 levels in PDLSCs. NAT10 overexpression further promoted the osteogenic differentiation of compressive force treated PDLSCs. Besides, NAT10 overexpression increased ac4C levels of BMP2 and enhanced the mRNA stability of BMP2. Remodelin treatment significantly decreased the ac4C and mRNA levels of BMP2. Furthermore, BMP2 silencing reversed the role of NAT10 in the compressive force treated PDLSCs.

CONCLUSION

This study demonstrated that compressive force promotes cell viability and osteogenic differentiation of PDLSCs by regulating BMP2 levels mediated by NAT10. NAT10 mediated ac4C levels of BMP2 is the key signaling axis of orthodontic stress in promoting cell growth and osteogenic differentiation of PDLSCs.

PCBP1/2 and TDP43 Function as NAT10 Adaptors to Mediate mRNA ac4C Formation in Mammalian Cells

Massive numbers of modified bases in mRNAs sculpt the epitranscriptome and play vital roles in RNA metabolism. The only known acetylated RNA modification, N-4-acetylcytidine (ac4C), is highly conserved across cell types and among species. Although the GCN5-related acetyltransferase 10 (NAT10) functions as an ac4C writer, the mechanism underlying the acetylation process is largely unknown. In this study, the NAT10/PCBP/TDP43 complex mediated mRNA ac4C formation in mammalian cells is identified. RNA-binding proteins (RBPs) are identified, affiliated with two different families, poly(rC)-binding protein 1/2 (PCBP1/2) and TAR DNA binding protein 43 (TDP43), as NAT10 adaptors for mRNA tethering and substrate selection. Knockdown of the adaptors resulted in decreased mRNA acetylation abundance in HEK293T cells and ablated cytidine-rich ac4C motifs. The adaptors also affect the ac4C sites by recruiting NAT10 to their binding sequences. The presence of the NAT10/PCBP/TDP43 complex in mouse testes highlights its potential physiological functions in vivo. These findings reveal the composition of the mRNA ac4C writer complex in mammalian cells and expand the knowledge of mRNA acetylation and ac4C site preferences.

Post-Translational Modifications of RNA-Modifying Proteins in Cellular Dynamics and Disease Progression

RNA-modifying proteins, classified as "writers," "erasers," and "readers," dynamically modulate RNA by adding, removing, or interpreting chemical groups, thereby influencing RNA stability, functionality, and interactions. To date, over 170 distinct RNA chemical modifications and more than 100 RNA-modifying enzymes have been identified, with ongoing research expanding these numbers. Although significant progress has been made in understanding RNA modification, the regulatory mechanisms that govern RNA-modifying proteins themselves remain insufficiently explored. Post-translational modifications (PTMs) such as phosphorylation, ubiquitination, and acetylation are crucial in modulating the function and behavior of these proteins. However, the full extent of PTM influence on RNA-modifying proteins and their role in disease development remains to be fully elucidated. This review addresses these gaps by offering a comprehensive analysis of the roles PTMs play in regulating RNA-modifying proteins. Mechanistic insights are provided into how these modifications alter biological processes, contribute to cellular function, and drive disease progression. In addition, the current research landscape is examined, highlighting the therapeutic potential of targeting PTMs on RNA-modifying proteins for precision medicine. By advancing understanding of these regulatory networks, this review seeks to facilitate the development of more effective therapeutic strategies and inspire future research in the critical area of PTMs in RNA-modifying proteins.

m6A-driven NAT10 translation facilitates fatty acid metabolic rewiring to suppress ferroptosis and promote ovarian tumorigenesis through enhancing ACOT7 mRNA acetylation

RNA epigenetic modifications have been implicated in cancer progression. However, the interplay between distinct RNA modifications and its role in cancer metabolism remain largely unexplored. Our study demonstrates that N-acetyltransferase 10 (NAT10) is notably upregulated in ovarian cancer (OC), correlating with poor patient prognosis. IGF2BP1 enhances the translation of NAT10 mRNA in an m6A-dependent manner in OC cells. NAT10 drives tumorigenesis by mediating N4-acetylcytidine (ac4C) modification of ACOT7 mRNA, thereby augmenting its stability and translation. This NAT10-ACOT7 axis modulates fatty acid metabolism in cancer cells and promotes tumor progression by suppressing ferroptosis. Additionally, our research identifies fludarabine as a small molecule inhibitor targeting NAT10, inhibits the ac4C modification and expression of ACOT7 mRNA. By using cell derived xenograft model and patient derived organoid model, we show that fludarabine effectively suppresses ovarian tumorigenesis. Overall, our study highlights the pivotal role of the NAT10-ACOT7 axis in the malignant cancer progression, underscoring the potential of targeting NAT10-mediated ac4C modification as a viable therapeutic strategy for this disease.

Loss of NAT10 Reduces the Translation of Kmt5a mRNA Through ac4C Modification in Cardiomyocytes and Induces Heart Failure

BACKGROUND

In the past decade, the biological functions of various RNA modifications in mammals have been uncovered. N4-acetylcytidine (ac4C), a highly conserved RNA modification, has been implicated in human diseases. Despite this, the involvement of RNA ac4C modification in cardiac physiology and pathology remains incompletely understood. NAT10 (N-acetyltransferase 10) stands as the sole acetyltransferase known to catalyze RNA ac4C modification. This study aims to explore the role of NAT10 and ac4C modification in cardiac physiology and pathology.

METHODS AND RESULTS

Cardiac-specific knockout of NAT10, leading to reduced RNA ac4C modification, during both neonatal and adult stages resulted in severe heart failure. NAT10 deficiency induced cardiomyocyte apoptosis, a crucial step in heart failure pathogenesis, supported by in vitro data. Activation of the p53 signaling pathway was closely associated with enhanced apoptosis in NAT10-deficient cardiomyocytes. As ac4C modification on mRNA influences translational efficiency, we employed ribosome footprints coupled with RNA sequencing to explore genome-wide translational efficiency changes caused by NAT10 deficiency. We identified and validated that the translational efficiency of Kmt5a was suppressed in NAT10 knockout hearts due to reduced ac4C modification on its mRNA. This finding was consistent with the observation that Kmt5a protein levels were reduced in heart failure despite unchanged mRNA expression. Knockdown of Kmt5a in cardiomyocytes recapitulated the phenotype of NAT10 deficiency, including increased cardiomyocyte apoptosis and activated p53 signaling. Finally, overexpression of Kmt5a rescued cardiomyocyte apoptosis and p53 activation induced by NAT10 inhibition.

CONCLUSIONS

Our study highlights the significance of NAT10 in cardiomyocyte physiology, demonstrating that NAT10 loss is sufficient to induce cardiomyocyte apoptosis and heart failure. NAT10 regulates the translational efficiency of Kmt5a, a key mediator, through mRNA ac4C modification during heart failure.

NAT10 Mediates XPO1 mRNA N4-acetylation and Promotes Drug Resistance of Myeloma Cells

The eventually developed chemoresistance to proteasome inhibitors (PIs) is a major hurdle in curing patients with multiple myeloma (MM) and a key cause of poor prognosis, however the underlying molecular mechanisms of chemoresistance is still poorly understood. Herein, we provide evidences that N-acetyltransferase 10 (NAT10), a catalytic enzyme involving in the acetylation modification of RNA, is overexpressed in the BTZ-resistant (BR) MM cell lines and predicts poor outcomes in the clinic. Further manipulating of NAT10 gene expression in MM cells shows that enforced NAT10 expression decreases sensitivity to PI, however knockdown of NAT10 enhances anti-tumor efficacy of PIs in MM cells in vitro and in vivo. Acetylated RNA immunoprecipitation sequencing (acRIP-seq) combined with RIP-qPCR analysis identifies exportin 1 (XPO1) as an important downstream target of NAT10, with promotes N4-acetylcytidine (ac4C) modification of XPO1 mRNA. Importantly, expressions of XPO1 and NAT10 are meaningfully correlated in bone biopsies from the relapsed/refractory (R/R) MM patients, which were also highly associated with poor outcome. Translationally, dual pharmacological inhibition of NAT10 and XPO1 sensitizes MM cells to BTZ treatment in both cell lines and in a xenograft mouse model of MM. Thus, our study elucidates previously unrecognized role of ac4C modification of XPO1 mRNA in the chemoresistance of MM and provides a potential option for clinical management of R/R MM patients in the clinic.

NAT10 inhibition promotes ac4C-dependent ferroptosis to counteract sorafenib resistance in nasopharyngeal carcinoma

Sorafenib, an anticancer drug, has been shown to induce ferroptosis in cancer cells. However, resistance to sorafenib greatly limits its therapeutic efficacy, and the exact mechanism of resistance is not fully understood. This study investigated the role of N-Acetyltransferase 10 (NAT10) in influencing the anticancer activity of sorafenib in nasopharyngeal carcinoma (NPC) and its molecular mechanism. NAT10 expression was significantly upregulated in NPC. Mechanistically, NAT10 promotes proteins of solute carrier family 7 member 11 (SLC7A11) expression through ac4C acetylation, inhibiting sorafenib-induced ferroptosis in NPC cells. The combined application of sorafenib and the NAT10 inhibitor remodelin significantly inhibits SLC7A11 expression and promotes ferroptosis in NPC cells. In vivo knockout of NAT10 inhibited the growth of sorafenib-resistant NPC. Our findings suggest that NAT10 inhibition might be a promising therapeutic approach to enhance the anticancer activity of sorafenib.

RNA ac4C modification in cancer: Unraveling multifaceted roles and promising therapeutic horizons

RNA modifications play a crucial role in cancer development, profoundly influencing various stages of the RNA lifecycle. These stages encompass nuclear processing, nuclear export, splicing, and translation in the cytoplasm. Among RNA modifications, RNA ac4C modification, also known as N4-acetylcytidine, stands out for its unique role in acetylation processes. Specific proteins regulate RNA ac4C modification, maintaining the dynamic and reversible nature of these changes. This review explores the molecular mechanisms and biological functions of RNA ac4C modification. It examines the intricate ways in which RNA ac4C modification influences the pathogenesis and progression of cancer. Additionally, the review provides an integrated overview of the current methodologies for detecting RNA ac4C modification. Exploring the potential applications of manipulating this modification suggests avenues for novel therapeutic strategies, potentially leading to more effective cancer treatments in the future.

Targeting NAT10 inhibits osteosarcoma progression via ATF4/ASNS-mediated asparagine biosynthesis

Despite advances in treatment, the prognosis of patients with osteosarcoma remains unsatisfactory, and searching for potential targets is imperative. Here, we identify N4-acetylcytidine (ac4C) acetyltransferase 10 (NAT10) as a candidate therapeutic target in osteosarcoma through functional screening. NAT10 overexpression is correlated with a poor prognosis, and NAT10 knockout inhibits osteosarcoma progression. Mechanistically, NAT10 enhances mRNA stability of activating transcription factor 4 (ATF4) through ac4C modification. ATF4 induces the transcription of asparagine synthetase (ASNS), which catalyzes asparagine (Asn) biosynthesis, facilitating osteosarcoma progression. Utilizing virtual screening, we identify paliperidone and AG-401 as potential NAT10 inhibitors, and both inhibitors are found to bind to NAT10 proteins. Inhibiting NAT10 suppresses osteosarcoma progression in vivo. Combined treatment using paliperidone and AG-401 produces synergistic inhibition for osteosarcoma in patient-derived xenograft (PDX) models. Our findings demonstrate that NAT10 facilitates osteosarcoma progression through the ATF4/ASNS/Asn axis, and pharmacological inhibition of NAT10 may be a feasible therapeutic approach for osteosarcoma.

Acetylcytidine modification of DDX41 and ZNF746 by N-acetyltransferase 10 contributes to chemoresistance of melanoma

Background

Rapidly developed chemoresistance to dacarbazine (DTIC) is a major obstacle in the clinical management of melanoma; however, the roles and mechanisms of epi-transcriptomic RNA modification in this process have not been investigated.

Method

DTIC-resistant (DR) melanoma cells were established for bulk RNA sequencing. The expressions of mRNAs were detected using qRT-PCR, and protein levels were determined using Western blotting and immunohistochemistry. Acetylated RNAs were detected by dot blotting and immunoprecipitation sequencing (acRIP-seq). A lung metastasis mouse model of melanoma was established to evaluate the anti-melanoma effects in vivo.

Results

We identified that the expression of N-acetyltransferase 10 (NAT10), a catalytic enzyme for the N 4-acetylcytidine (ac4C) modification of RNA, was significantly upregulated in the DR cells. Clinically, NAT10 expression was elevated in disease progression samples and predicted a poor outcome. Using ac4C RNA immunoprecipitation (ac4C-RIP), we found that the mRNAs of two C2H2 zinc finger transcriptional factors, DDX41 and ZNF746, were targets of NAT10-mediated ac4C modification. Gain- and loss-of-function experiments in NAT10, or in DDX41 and ZNF746, altered the chemosensitivity of melanoma accordingly, and the two target genes also negatively correlated with clinical outcomes. Finally, pharmacological inhibition of NAT10 with Remodelin sensitized melanoma cells to DTIC treatment in vitro and in a mouse xenograft model.

Conclusion

Our study elucidates the previously unrecognized role of NAT10-mediated ac4C modification in the chemoresistance of melanoma and provides a rationale for developing new strategies to overcome chemoresistance in melanoma patients.

NAT10 and cytidine acetylation in mRNA: intersecting paths in development and disease

N4-acetylcytidine (ac4C) is an RNA modification that is catalyzed by the enzyme NAT10. Constitutively found in tRNA and rRNA, ac4C displays a dynamic presence in mRNA that is shaped by developmental and induced shifts in NAT10 levels. However, deciphering ac4C functions in mRNA has been hampered by its context-dependent influences in translation and the complexity of isolating effects on specific mRNAs from other NAT10 activities. Recent advances have begun to overcome these obstacles by leveraging natural variations in mRNA acetylation in cancer, developmental transitions, and immune responses. Here, we synthesize the current literature with a focus on nuances that may fuel the perception of cellular discrepancies toward the development of a cohesive model of ac4C function in mRNA.

Acetylcytidine modification of Amotl1 by N-acetyltransferase 10 contributes to cardiac fibrotic expansion in mice after myocardial infarction

Cardiac fibrosis is a pathological scarring process that impairs cardiac function. N-acetyltransferase 10 (Nat10) is recently identified as the key enzyme for the N4-acetylcytidine (ac4C) modification of mRNAs. In this study, we investigated the role of Nat10 in cardiac fibrosis following myocardial infarction (MI) and the related mechanisms. MI was induced in mice by ligation of the left anterior descending coronary artery; cardiac function was assessed with echocardiography. We showed that both the mRNA and protein expression levels of Nat10 were significantly increased in the infarct zone and border zone 4 weeks post-MI, and the expression of Nat10 in cardiac fibroblasts was significantly higher compared with that in cardiomyocytes after MI. Fibroblast-specific overexpression of Nat10 promoted collagen deposition and induced cardiac systolic dysfunction post-MI in mice. Conversely, fibroblast-specific knockout of Nat10 markedly relieved cardiac function impairment and extracellular matrix remodeling following MI. We then conducted ac4C-RNA binding protein immunoprecipitation-sequencing (RIP-seq) in cardiac fibroblasts transfected with Nat10 siRNA, and revealed that angiomotin-like 1 (Amotl1), an upstream regulator of the Hippo signaling pathway, was the target gene of Nat10. We demonstrated that Nat10-mediated ac4C modification of Amotl1 increased its mRNA stability and translation in neonatal cardiac fibroblasts, thereby increasing the interaction of Amotl1 with yes-associated protein 1 (Yap) and facilitating Yap translocation into the nucleus. Intriguingly, silencing of Amotl1 or Yap, as well as treatment with verteporfin, a selective and potent Yap inhibitor, attenuated the Nat10 overexpression-induced proliferation of cardiac fibroblasts and prevented their differentiation into myofibroblasts in vitro. In conclusion, this study highlights Nat10 as a crucial regulator of myocardial fibrosis following MI injury through ac4C modification of upstream activators within the Hippo/Yap signaling pathway.

N-acetyltransferase 10 facilitates tumorigenesis of diffuse large B-cell lymphoma by regulating AMPK/mTOR signalling through N4-acetylcytidine modification of SLC30A9

BACKGROUND

Accumulating studies suggested that posttranscriptional modifications exert a vital role in the tumorigenesis of diffuse large B-cell lymphoma (DLBCL). N4-acetylcytidine (ac4C) modification, catalyzed by the N-acetyltransferase 10 (NAT10), was a novel type of chemical modification that improves translation efficiency and mRNA stability.

METHODS

GEO databases and clinical samples were used to explore the expression and clinical value of NAT10 in DLBCL. CRISPER/Cas9-mediated knockout of NAT10 was performed to determine the biological functions of NAT10 in DLBCL. RNA sequencing, acetylated RNA immunoprecipitation sequencing (acRIP-seq), LC-MS/MS, RNA immunoprecipitation (RIP)-qPCR and RNA stability assays were performed to explore the mechanism by which NAT10 contributed to DLBCL progression.

RESULTS

Here, we demonstrated that NAT10-mediated ac4C modification regulated the occurrence and progression of DLBCL. Dysregulated N-acetyltransferases expression was found in DLBCL samples. High expression of NAT10 was associated with poor prognosis of DLBCL patients. Deletion of NAT10 expression inhibited cell proliferation and induced G0/G1 phase arrest. Furthermore, knockout of NAT10 increased the sensitivity of DLBCL cells to ibrutinib. AcRIP-seq identified solute carrier family 30 member 9 (SLC30A9) as a downstream target of NAT10 in DLBCL. NAT10 regulated the mRNA stability of SLC30A9 in an ac4C-dependent manner. Genetic silencing of SLC30A9 suppressed DLBCL cell growth via regulating the activation of AMP-activated protein kinase (AMPK) pathway.

CONCLUSION

Collectively, these findings highlighted the essential role of ac4C RNA modification mediated by NAT10 in DLBCL, and provided insights into novel epigenetic-based therapeutic strategies.

Non‐m6A RNA modifications in haematological malignancies

Dysregulated RNA modifications, stemming from the aberrant expression and/or malfunction of RNA modification regulators operating through various pathways, play pivotal roles in driving the progression of haematological malignancies. Among RNA modifications, N6-methyladenosine (m6A) RNA modification, the most abundant internal mRNA modification, stands out as the most extensively studied modification. This prominence underscores the crucial role of the layer of epitranscriptomic regulation in controlling haematopoietic cell fate and therefore the development of haematological malignancies. Additionally, other RNA modifications (non-m6A RNA modifications) have gained increasing attention for their essential roles in haematological malignancies. Although the roles of the m6A modification machinery in haematopoietic malignancies have been well reviewed thus far, such reviews are lacking for non-m6A RNA modifications. In this review, we mainly focus on the roles and implications of non-m6A RNA modifications, including N4-acetylcytidine, pseudouridylation, 5-methylcytosine, adenosine to inosine editing, 2'-O-methylation, N1-methyladenosine and N7-methylguanosine in haematopoietic malignancies. We summarise the regulatory enzymes and cellular functions of non-m6A RNA modifications, followed by the discussions of the recent studies on the biological roles and underlying mechanisms of non-m6A RNA modifications in haematological malignancies. We also highlight the potential of therapeutically targeting dysregulated non-m6A modifiers in blood cancer.

The positive feedback loop of the NAT10/Mybbp1a/p53 axis promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury

Ferroptosis is a nonapoptotic form of regulated cell death that has been reported to play a central role in cardiac ischemia‒reperfusion (I/R) injury. N-acetyltransferase 10 (NAT10) contributes to cardiomyocyte apoptosis by functioning as an RNA ac4c acetyltransferase, but its role in cardiomyocyte ferroptosis during I/R injury has not been determined. This study aimed to elucidate the role of NAT10 in cardiac ferroptosis as well as the underlying mechanism. The mRNA and protein levels of NAT10 were increased in mouse hearts after I/R and in cardiomyocytes that were exposed to hypoxia/reoxygenation. P53 acted as an endogenous activator of NAT10 during I/R in a transcription-dependent manner. Cardiac overexpression of NAT10 caused cardiomyocyte ferroptosis to exacerbate I/R injury, while cardiomyocyte-specific knockout of NAT10 or pharmacological inhibition of NAT10 with Remodelin had the opposite effects. The inhibition of cardiomyocyte ferroptosis by Fer-1 exerted superior cardioprotective effects against the NAT10-induced exacerbation of post-I/R cardiac damage than the inhibition of apoptosis by emricasan. Mechanistically, NAT10 induced the ac4C modification of Mybbp1a, increasing its stability, which in turn activated p53 and subsequently repressed the transcription of the anti-ferroptotic gene SLC7A11. Moreover, knockdown of Mybbp1a partially abolished the detrimental effects of NAT10 overexpression on cardiomyocyte ferroptosis and cardiac I/R injury. Collectively, our study revealed that p53 and NAT10 interdependently cooperate to form a positive feedback loop that promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury, suggesting that targeting the NAT10/Mybbp1a/p53 axis may be a novel approach for treating cardiac I/R.

Acetyl-CoA-dependent ac4C acetylation promotes the osteogenic differentiation of LPS-stimulated BMSCs

The impaired osteogenic capability of bone marrow mesenchymal stem cells (BMSCs) caused by persistent inflammation is the main pathogenesis of inflammatory bone diseases. Recent studies show that metabolism is disturbed in osteogenically differentiated BMSCs in response to Lipopolysaccharide (LPS) treatment, while the mechanism involved remains incompletely revealed. Herein, we demonstrated that BMSCs adapted their metabolism to regulate acetyl-coenzyme A (acetyl-CoA) availability and RNA acetylation level, ultimately affecting osteogenic differentiation. The mitochondrial dysfunction and impaired osteogenic potential upon inflammatory conditions accompanied by the reduced acetyl-CoA content, which in turn suppressed N4-acetylation (ac4C) level. Supplying acetyl-CoA by sodium citrate (SC) addition rescued ac4C level and promoted the osteogenic capacity of LPS-treated cells through the ATP citrate lyase (ACLY) pathway. N-acetyltransferase 10 (NAT10) inhibitor remodelin reduced ac4C level and consequently impeded osteogenic capacity. Meanwhile, the osteo-promotive effect of acetyl-CoA-dependent ac4C might be attributed to fatty acid oxidation (FAO), as evidenced by activating FAO by L-carnitine supplementation counteracted remodelin-induced inhibition of osteogenesis. Further in vivo experiments confirmed the promotive role of acetyl-CoA in the endogenous bone regeneration in rat inflammatory mandibular defects. Our study uncovered a metabolic-epigenetic axis comprising acetyl-CoA and ac4C modification in the process of inflammatory osteogenesis of BMSCs and suggested a new target for bone tissue repair in the context of inflammatory bone diseases.

NAT10-mediated ac4C modification promotes stemness and chemoresistance of colon cancer by stabilizing NANOGP8

Background

Colon cancer (CC) stem cells can self-renew as well as expand, thereby promoting tumor progression and conferring resistance to chemotherapeutic agents. The acetyltransferase NAT10 mediates N4-acetylcytidine (ac4C) modification, which in turn drives tumorigenesis, metastasis, stemness properties maintenance, and cell fate decisions. Nonetheless, the specific involvement of ac4C modification mediated by NAT10 in regulating stemness and chemosensitivity in CC remains undetermined.

Methods

The levels of NAT10 in normal colon and chemoresistant CC tissues were determined utilizing quantitative real-time polymerase chain reaction alongside immunohistochemistry. Assessing cancer cell stemness and chemosensitivity was conducted by various methods including spheroid and colony formation, western blotting, and flow cytometry. RNA-Seq was used to identify target genes, and RNA immunoprecipitation analysis was used to explore the potential mechanisms.

Results

We observed NAT10 overexpression and increased ac4C modification levels in chemoresistant CC tissues. The in vivo and in vitro analysis findings suggested that NAT10 promoted CC cell stemness while suppressing their chemosensitivity. Conversely, Remodelin, a NAT10-specific inhibitor, enhanced CC cell chemosensitivity. Mechanistically, NAT10 increased the level of NANOGP8 ac4C modification and promoted NANOGP8 mRNA stability.

Conclusions

NAT10 promotes the maintenance of stemness and chemoresistance in CC cells by augmenting the mRNA stability of NANOGP8. The inhibition of NAT10 via Remodelin improves chemotherapeutic efficacy and impedes CC progression.

Fisetin nanoparticles based on cells cycle and apoptosis intervention for the treatment of lymphoma and leukemia

Lymphoma and leukemia are both hematological system tumors with complex etiology, and mainly treated with chemotherapeutic drugs. However, therapeutic drugs can interrupt curative effect due to different side effects. Therefore, it is worthwhile to develop a novel therapeutic for providing insights for clinical tumor treatment. In this study, we developed a fisetin nanoparticles (Fisetin NPs) through a self-assembled method, and investigated the activity and potential mechanism of Fisetin NPs against lymphoma and leukemia. The spherical and uniformly distributed Fisetin NPs effectively inhibited both tumor cells proliferation, arrested EL4 cells G0/G1 phase and K562 cells G2/M phase, and induced apoptosis in vitro. In vivo, Fisetin NPs exhibited excellent tumor growth inhibition, effective inhibition of cell proliferation and angiogenesis, significant induction of apoptosis and ideal safety. Mechanically, fisetin upregulated genes (Fas, Pidd, Puma, Apaf1, and p21) in the p53 signaling pathway and bound to N-acetyltransferase 10 (NAT10), ribosomal protein L34 (RPL34) and GTP binding protein 4 (GTPBP4). Collectively, Fisetin NPs have promising therapeutic effects on lymphoma and leukemia, which are of great significant for clinical implications.

Dissecting the oncogenic properties of essential RNA-modifying enzymes: a focus on NAT10

Chemical modifications of ribonucleotides significantly alter the physicochemical properties and functions of RNA. Initially perceived as static and essential marks in ribosomal RNA (rRNA) and transfer RNA (tRNA), recent discoveries unveiled a dynamic landscape of RNA modifications in messenger RNA (mRNA) and other regulatory RNAs. These findings spurred extensive efforts to map the distribution and function of RNA modifications, aiming to elucidate their distribution and functional significance in normal cellular homeostasis and pathological states. Significant dysregulation of RNA modifications is extensively documented in cancers, accentuating the potential of RNA-modifying enzymes as therapeutic targets. However, the essential role of several RNA-modifying enzymes in normal physiological functions raises concerns about potential side effects. A notable example is N-acetyltransferase 10 (NAT10), which is responsible for acetylating cytidines in RNA. While emerging evidence positions NAT10 as an oncogenic factor and a potential target in various cancer types, its essential role in normal cellular processes complicates the development of targeted therapies. This review aims to comprehensively analyze the essential and oncogenic properties of NAT10. We discuss its crucial role in normal cell biology and aging alongside its contribution to cancer development and progression. We advocate for agnostic approaches to disentangling the intertwined essential and oncogenic functions of RNA-modifying enzymes. Such approaches are crucial for understanding the full spectrum of RNA-modifying enzymes and imperative for designing effective and safe therapeutic strategies.

NAT10-mediated ac4C modification promotes ectoderm differentiation of human embryonic stem cells via acetylating NR2F1 mRNA

Cell fate determination in mammalian development is complex and precisely controlled and accumulating evidence indicates that epigenetic mechanisms are crucially involved. N4-acetylcytidine (ac4C) is a recently identified modification of messenger RNA (mRNA); however, its functions are still elusive in mammalian. Here, we show that N-acetyltransferase 10 (NAT10)-mediated ac4C modification promotes ectoderm differentiation of human embryonic stem cells (hESCs) by acetylating nuclear receptor subfamily 2 group F member 1 (NR2F1) mRNA to enhance translation efficiency (TE). Acetylated RNA immunoprecipitation sequencing (acRIP-seq) revealed that levels of ac4C modification were higher in ectodermal neuroepithelial progenitor (NEP) cells than in hESCs or mesoendoderm cells. In addition, integrated analysis of acRIP-seq and ribosome profiling sequencing revealed that NAT10 catalysed ac4C modification to improve TE in NEP cells. RIP-qRT-PCR analysis identified an interaction between NAT10 and NR2F1 mRNA in NEP cells and NR2F1 accelerated the nucleus-to-cytoplasm translocation of yes-associated protein 1, which contributed to ectodermal differentiation of hESCs. Collectively, these findings point out the novel regulatory role of ac4C modification in the early ectodermal differentiation of hESCs and will provide a new strategy for the treatment of neuroectodermal defects diseases.

N-Acetyltransferase 10 represses Uqcr11 and Uqcrb independently of ac4C modification to promote heart regeneration

Translational control is crucial for protein production in various biological contexts. Here, we use Ribo-seq and RNA-seq to show that genes related to oxidative phosphorylation are translationally downregulated during heart regeneration. We find that Nat10 regulates the expression of Uqcr11 and Uqcrb mRNAs in mouse and human cardiomyocytes. In mice, overexpression of Nat10 in cardiomyocytes promotes cardiac regeneration and improves cardiac function after injury. Conversely, treating neonatal mice with Remodelin-a Nat10 pharmacological inhibitor-or genetically removing Nat10 from their cardiomyocytes both inhibit heart regeneration. Mechanistically, Nat10 suppresses the expression of Uqcr11 and Uqcrb independently of its ac4C enzyme activity. This suppression weakens mitochondrial respiration and enhances the glycolytic capacity of the cardiomyocytes, leading to metabolic reprogramming. We also observe that the expression of Nat10 is downregulated in the cardiomyocytes of P7 male pig hearts compared to P1 controls. The levels of Nat10 are also lower in female human failing hearts than non-failing hearts. We further identify the specific binding regions of Nat10, and validate the pro-proliferative effects of Nat10 in cardiomyocytes derived from human embryonic stem cells. Our findings indicate that Nat10 is an epigenetic regulator during heart regeneration and could potentially become a clinical target.

Revealing the pharmacological effects of Remodelin against osteosarcoma based on network pharmacology, acRIP-seq and experimental validation

Osteosarcoma (OS) is the most common primary malignant tumor of bone. Remodelin, an inhibitor of the N (4)-Acetylcytidine (ac4C) acetylation modifying enzyme N-acetyltransferase 10 (NAT10), has been shown to have therapeutic effects on cancer in several studies, and our previous studies have confirmed the inhibitory effect of Remodelin on OS cells, however, the mechanism of action has not yet been elucidated. We used network pharmacological analysis to quantify the therapeutic targets of Remodelin against OS. acRIP-seq and RNA-seq were performed to investigate the inhibitory activity of Remodelin on acetylation and its effect on the transcriptome after intervening in OS cells U2OS with Remodelin in vitro. Key target genes were deduced based on their pharmacological properties, combined with network pharmacology results and sequencing results. Finally, the deduced target genes were validated with vitro experiments. Network pharmacological analysis showed that 2291 OS-related target genes and 369 Remodelin-related target genes were obtained, and 116 overlapping genes were identified as Remodelin targets for OS treatment. Sequencing results showed that a total of 13,736 statistically significant ac4C modification peaks were detected by acRIP-seq, including 6938 hypoacetylation modifications and 6798 hyperacetylation modifications. A total of 2350 statistically significant mRNAs were detected by RNA-seq, of which 830 were up-regulated and 1520 were down-regulated. Association analyses identified a total of 382 genes that were Hypoacetylated-down, consistent with inhibition of mRNA acetylation and expression by Remodelin. Five genes, CASP3, ESR2, FGFR2, IGF1 and MAPK1, were identified as key therapeutic targets of Remodelin against OS. Finally, in vitro experiments, CCK-8 and qRT-PCR demonstrated that Remodelin indeed inhibited the proliferation of OS cells and reduced the expression of three genes: ESR2, IGF1, and MAPK1. In conclusion, ESR2, IGF1 and MAPK1 were identified as key therapeutic targets of Remodelin against OS. This reveals the target of Remodelin's pharmacological action on OS and provides new ideas for the treatment of OS.

CircMAST1 inhibits cervical cancer progression by hindering the N4-acetylcytidine modification of YAP mRNA

BACKGROUND

Cervical cancer (CCa) is the fourth most common cancer among females, with high incidence and mortality rates. Circular RNAs (circRNAs) are key regulators of various biological processes in cancer. However, the biological role of circRNAs in cervical cancer (CCa) remains largely unknown. This study aimed to elucidate the role of circMAST1 in CCa.

METHODS

CircRNAs related to CCa progression were identified via a circRNA microarray. The relationship between circMAST1 levels and clinicopathological features of CCa was evaluated using the clinical specimens and data of 131 patients with CCa. In vivo and in vitro experiments, including xenograft animal models, cell proliferation assay, transwell assay, RNA pull-down assay, whole-transcriptome sequencing, RIP assay, and RNA-FISH, were performed to investigate the effects of circMAST1 on the malignant behavior of CCa.

RESULTS

CircMAST1 was significantly downregulated in CCa tissues, and low expression of CircMAST1 was correlated with a poor prognosis. Moreover, our results demonstrated that circMAST1 inhibited tumor growth and lymph node metastasis of CCa. Mechanistically, circMAST1 competitively sequestered N-acetyltransferase 10 (NAT10) and hindered Yes-associated protein (YAP) mRNA ac4C modification to promote its degradation and inhibit tumor progression in CCa.

CONCLUSIONS

CircMAST1 plays a major suppressive role in the tumor growth and metastasis of CCa. In particular, circMAST1 can serve as a potential biomarker and novel target for CCa.

Ribosome profiling: a powerful tool in oncological research

Neoplastic cells need to adapt their gene expression pattern to survive in an ever-changing or unfavorable tumor microenvironment. Protein synthesis (or mRNA translation), an essential part of gene expression, is dysregulated in cancer. The emergence of distinct translatomic technologies has revolutionized oncological studies to elucidate translational regulatory mechanisms. Ribosome profiling can provide adequate information on diverse aspects of translation by aiding in quantitatively analyzing the intensity of translating ribosome-protected fragments. Here, we review the primary currently used translatomics techniques and highlight their advantages and disadvantages as tools for translatomics studies. Subsequently, we clarified the areas in which ribosome profiling could be applied to better understand translational control. Finally, we summarized the latest advances in cancer studies using ribosome profiling to highlight the extensive application of this powerful and promising translatomic tool.

A novel scaffold long-acting selective estrogen receptor antagonist and degrader with superior preclinical profile against ER+ breast cancer

Breast cancer is one of the most common malignant tumors in women worldwide, with the majority of cases showing expression of estrogen receptors (ERs). Although drugs targeting ER have significantly improved survival rates in ER-positive patients, drug resistance remains an unmet clinical need. Fulvestrant, which overcomes selective estrogen receptor modulator (SERM) and AI (aromatase inhibitor) resistance, is currently the only long-acting selective estrogen receptor degrader (SERD) approved for both first and second-line settings. However, it fails to achieve satisfactory efficacy due to its poor solubility. Therefore, we designed and synthesized a series of novel scaffold (THC) derivatives, identifying their activities as ER antagonists and degraders. G-5b, the optimal compound, exhibited binding, antagonistic, degradation or anti-proliferative activities comparable to fulvestrant in ER+ wild type and mutants breast cancer cells. Notably, G-5b showed considerably improved stability and solubility. Research into the underlying mechanism indicated that G-5b engaged the proteasome pathway to degrade ER, subsequently inhibiting the ER signaling pathway and leading to the induction of apoptosis and cell cycle arrest events. Furthermore, G-5b displayed superior in vivo pharmacokinetics and pharmacodynamics properties, coupled with a favorable safety profile in the MCF-7 tamoxifen-resistant (MCF-7/TR) tumor xenograft model. Collectively, G-5b has emerged as a highly promising lead compound, offering potent antagonistic and degradation activities, positioning it as a novel long-acting SERD worthy of further refinement and optimization.

Emerging roles of RNA ac4C modification and NAT10 in mammalian development and human diseases

RNA ac4C modification is a novel and rare chemical modification observed in mRNA. Traditional biochemical studies had primarily associated ac4C modification with tRNA and rRNA until in 2018, Arango D et al. first reported the presence of ac4C modification on mRNA and demonstrated its critical role in mRNA stability and translation regulation. Furthermore, they established that the ac4C modification on mRNA is mediated by the classical N-acetyltransferase NAT10. Subsequent studies have underscored the essential implications of NAT10 and mRNA ac4C modification across both physiological and pathological regulatory processes. In this review, we aimed to explore the discovery history of RNA ac4C modification, its detection methods, and its regulatory mechanisms in disease and physiological development. We offer a forward-looking examination and discourse concerning the employment of RNA ac4C modification as a prospective therapeutic strategy across diverse diseases. Furthermore, we comprehensively summarize the functions and mechanisms of NAT10 in gene expression regulation and pathogenesis independent of RNA ac4C modification.

The emerging roles of ac4C acetylation "writer" NAT10 in tumorigenesis: A comprehensive review

The quick progress of epigenetic study has kindled new hope for treating many cancers. When it comes to RNA epigenetics, the ac4C acetylation modification is showing promise, whereas N-acetyltransferase 10 plays a wide range of biological functions, has a significant impact on cellular life events, and is frequently highly expressed in many malignant tumors. N-acetyltransferase 10 is an acetyltransferase with important biological involvement in cellular processes and lifespan. Because it is highly expressed in many malignant tumors, it is considered a pro-carcinogenic gene. The review aims to introduce NAT10, summarize the effects of ac4C acetylation on tumor growth from multiple angles, and discuss the possible therapeutic targeting of NAT10 and the future directions of ac4C acetylation investigations.

NAT10 Is Involved in Cardiac Remodeling Through ac4C-Mediated Transcriptomic Regulation

BACKGROUND

Heart failure, characterized by cardiac remodeling, is associated with abnormal epigenetic processes and aberrant gene expression. Here, we aimed to elucidate the effects and mechanisms of NAT10 (N-acetyltransferase 10)-mediated N4-acetylcytidine (ac4C) acetylation during cardiac remodeling.

METHODS

NAT10 and ac4C expression were detected in both human and mouse subjects with cardiac remodeling through multiple assays. Subsequently, acetylated RNA immunoprecipitation and sequencing, thiol-linked alkylation for the metabolic sequencing of RNA (SLAM-seq), and ribosome sequencing (Ribo-seq) were employed to elucidate the role of ac4C-modified posttranscriptional regulation in cardiac remodeling. Additionally, functional experiments involving the overexpression or knockdown of NAT10 were conducted in mice models challenged with Ang II (angiotensin II) and transverse aortic constriction.

RESULTS

NAT10 expression and RNA ac4C levels were increased in in vitro and in vivo cardiac remodeling models, as well as in patients with cardiac hypertrophy. Silencing and inhibiting NAT10 attenuated Ang II-induced cardiomyocyte hypertrophy and cardiofibroblast activation. Next-generation sequencing revealed ac4C changes in both mice and humans with cardiac hypertrophy were associated with changes in global mRNA abundance, stability, and translation efficiency. Mechanistically, NAT10 could enhance the stability and translation efficiency of CD47 and ROCK2 transcripts by upregulating their mRNA ac4C modification, thereby resulting in an increase in their protein expression during cardiac remodeling. Furthermore, the administration of Remodelin, a NAT10 inhibitor, has been shown to prevent cardiac functional impairments in mice subjected to transverse aortic constriction by suppressing cardiac fibrosis, hypertrophy, and inflammatory responses, while also regulating the expression levels of CD47 and ROCK2 (Rho associated coiled-coil containing protein kinase 2).

CONCLUSIONS

Therefore, our data suggest that modulating epitranscriptomic processes, such as ac4C acetylation through NAT10, may be a promising therapeutic target against cardiac remodeling.

N4-acetylcytidine-dependent GLMP mRNA stabilization by NAT10 promotes head and neck squamous cell carcinoma metastasis and remodels tumor microenvironment through MAPK/ERK signaling pathway

N4-acetylcytidine (ac4C) is a post-transcriptional RNA modification that regulates in various important biological processes. However, its role in human cancer, especially lymph node metastasis, remains largely unknown. Here, we demonstrated N-Acetyltransferase 10 (NAT10), as the only known "writer" of ac4C mRNA modification, was highly expressed in head and neck squamous cell carcinoma (HNSCC) patients with lymph node metastasis. High NAT10 levels in the lymph nodes of patients with HNSCC patients are a predictor of poor overall survival. Moreover, we found that high expression of NAT10 was positively upregulated by Nuclear Respiratory Factor 1 (NRF1) transcription factor. Gain- and loss-of-function experiments displayed that NAT10 promoted cell metastasis in mice. Mechanistically, NAT10 induced ac4C modification of Glycosylated Lysosomal Membrane Protein (GLMP) and stabilized its mRNA, which triggered the activation of the MAPK/ERK signaling pathway. Finally, the NAT10-specific inhibitor, remodelin, could inhibit HNSCC tumorigenesis in a 4-Nitroquinoline 1-oxide (4NQO)-induced murine tumor model and remodel the tumor microenvironment, including angiogenesis, CD8+ T cells and Treg recruitment. These results demonstrate that NAT10 promotes lymph node metastasis in HNSCC via ac4C-dependent stabilization of the GLMP transcript, providing a potential epitranscriptomic-targeted therapeutic strategy for HNSCC.

NAT10 regulates the repair of UVB-induced DNA damage and tumorigenicity

Chemical modifications in messenger RNA (mRNA) regulate gene expression and play critical roles in stress responses and diseases. Recently we have shown that N6-methyladenosine (m6A), the most abundant mRNA modification, promotes the repair of UVB-induced DNA damage by regulating global genome nucleotide excision repair (GG-NER). However, the roles of other mRNA modifications in the UVB-induced damage response remain understudied. N4-acetylcytidine (ac4C) is deposited in mRNA by the RNA-binding acetyltransferase NAT10. This NAT10-mediated ac4C in mRNA has been reported to increase both mRNA stability and translation. However, the role of ac4C and NAT10 in the UVB-induced DNA damage response remains poorly understood. Here we show that NAT10 plays a critical role in the repair of UVB-induced DNA damage lesions through regulating the expression of the key GG-NER gene DDB2. We found that knockdown of NAT10 enhanced the repair of UVB-induced DNA damage lesions by promoting the mRNA stability of DDB2. Our findings are in contrast to the previously reported role of NAT10-mediated ac4C deposition in promoting mRNA stability and may represent a novel mechanism for ac4C in the UVB damage response. Furthermore, NAT10 knockdown in skin cancer cells decreased skin cancer cell proliferation in vitro and tumorigenicity in vivo. Chronic UVB irradiation increases NAT10 protein levels in mouse skin. Taken together, our findings demonstrate a novel role for NAT10 in the repair of UVB-induced DNA damage products by decreasing the mRNA stability of DDB2 and suggest that NAT10 is a potential novel target for preventing and treating skin cancer.

RNA modification: mechanisms and therapeutic targets

RNA modifications are dynamic and reversible chemical modifications on substrate RNA that are regulated by specific modifying enzymes. They play important roles in the regulation of many biological processes in various diseases, such as the development of cancer and other diseases. With the help of advanced sequencing technologies, the role of RNA modifications has caught increasing attention in human diseases in scientific research. In this review, we briefly summarized the basic mechanisms of several common RNA modifications, including m6A, m5C, m1A, m7G, Ψ, A-to-I editing and ac4C. Importantly, we discussed their potential functions in human diseases, including cancer, neurological disorders, cardiovascular diseases, metabolic diseases, genetic and developmental diseases, as well as immune disorders. Through the "writing-erasing-reading" mechanisms, RNA modifications regulate the stability, translation, and localization of pivotal disease-related mRNAs to manipulate disease development. Moreover, we also highlighted in this review all currently available RNA-modifier-targeting small molecular inhibitors or activators, most of which are designed against m6A-related enzymes, such as METTL3, FTO and ALKBH5. This review provides clues for potential clinical therapy as well as future study directions in the RNA modification field. More in-depth studies on RNA modifications, their roles in human diseases and further development of their inhibitors or activators are needed for a thorough understanding of epitranscriptomics as well as diagnosis, treatment, and prognosis of human diseases.

Inhibition of VCP modulates NF-κB signaling pathway to suppress multiple myeloma cell proliferation and osteoclast differentiation

Multiple myeloma (MM) is the second most common hematological malignancy, in which the dysfunction of the ubiquitin-proteasome pathway is associated with the pathogenesis. The valosin containing protein (VCP)/p97, a member of the AAA+ ATPase family, possesses multiple functions to regulate the protein quality control including ubiquitin-proteasome system and molecular chaperone. VCP is involved in the occurrence and development of various tumors while still elusive in MM. VCP inhibitors have gradually shown great potential for cancer treatment. This study aims to identify if VCP is a therapeutic target in MM and confirm the effect of a novel inhibitor of VCP (VCP20) on MM. We found that VCP was elevated in MM patients and correlated with shorter survival in clinical TT2 cohort. Silencing VCP using siRNA resulted in decreased MM cell proliferation via NF-κB signaling pathway. VCP20 evidently inhibited MM cell proliferation and osteoclast differentiation. Moreover, exosomes containing VCP derived from MM cells partially alleviated the inhibitory effect of VCP20 on cell proliferation and osteoclast differentiation. Mechanism study revealed that VCP20 inactivated the NF-κB signaling pathway by inhibiting ubiquitination degradation of IκBα. Furthermore, VCP20 suppressed MM cell proliferation, prolonged the survival of MM model mice and improved bone destruction in vivo. Collectively, our findings suggest that VCP is a novel target in MM progression. Targeting VCP with VCP20 suppresses malignancy progression of MM via inhibition of NF-κB signaling pathway.

N4-Acetylcytidine Drives Glycolysis Addiction in Gastric Cancer via NAT10/SEPT9/HIF-1α Positive Feedback Loop

Anti-angiogenic therapy has long been considered a promising strategy for solid cancers. Intrinsic resistance to hypoxia is a major cause for the failure of anti-angiogenic therapy, but the underlying mechanism remains unclear. Here, it is revealed that N4-acetylcytidine (ac4C), a newly identified mRNA modification, enhances hypoxia tolerance in gastric cancer (GC) cells by promoting glycolysis addiction. Specifically, acetyltransferase NAT10 transcription is regulated by HIF-1α, a key transcription factor of the cellular response to hypoxia. Further, acRIP-sequencing, Ribosome profiling sequencing, RNA-sequencing, and functional studies confirm that NAT10 in turn activates the HIF-1 pathway and subsequent glucose metabolism reprogramming by mediating SEPT9 mRNA ac4C modification. The formation of the NAT10/SEPT9/HIF-1α positive feedback loop leads to excessive activation of the HIF-1 pathway and induces glycolysis addiction. Combined anti-angiogenesis and ac4C inhibition attenuate hypoxia tolerance and inhibit tumor progression in vivo. This study highlights the critical roles of ac4C in the regulation of glycolysis addiction and proposes a promising strategy to overcome resistance to anti-angiogenic therapy by combining apatinib with ac4C inhibition.

NAT10, an RNA Cytidine Acetyltransferase, Regulates Ferroptosis in Cancer Cells

Recently, we reported that N-acetyltransferase 10 (NAT10) regulates fatty acid metabolism through ac4C-dependent RNA modification of key genes in cancer cells. During this work, we noticed ferroptosis as one of the most negatively enriched pathways among other pathways in NAT10-depleted cancer cells. In the current work, we explore the possibility of whether NAT10 acts as an epitranscriptomic regulator of the ferroptosis pathway in cancer cells. Global ac4C levels and expression of NAT10 with other ferroptosis-related genes were assessed via dotblot and RT-qPCR, respectively. Flow cytometry and biochemical analysis were used to assess oxidative stress and ferroptosis features. The ac4C-mediated mRNA stability was conducted using RIP-PCR and mRNA stability assay. Metabolites were profiled using LC-MS/MS. Our results showed significant downregulation in expression of essential genes related to ferroptosis, namely SLC7A11, GCLC, MAP1LC3A, and SLC39A8 in NAT10-depleted cancer cells. Further, we noticed a reduction in cystine uptake and reduced GSH levels, along with elevated ROS, and lipid peroxidation levels in NAT10-depleted cells. Consistently, overproduction of oxPLs, as well as increased mitochondrial depolarization and decreased activities of antioxidant enzymes, support the notion of ferroptosis induction in NAT10-depleted cancer cells. Mechanistically, a reduced ac4C level shortens the half-life of GCLC and SLC7A11 mRNA, resulting in low levels of intracellular cystine and reduced GSH, failing to detoxify ROS, and leading to increased cellular oxPLs, which facilitate ferroptosis induction. Collectively, our findings suggest that NAT10 restrains ferroptosis by stabilizing the SLC7A11 mRNA transcripts in order to avoid oxidative stress that induces oxidation of phospholipids to initiate ferroptosis.

NAT10-mediated AXL mRNA N4-acetylcytidine modification promotes pancreatic carcinoma progression

Although the patient's survival time in various cancers has significantly increased in recent decades, the overall 5-year survival rate of pancreatic ductal adenocarcinoma (PDAC) has remained virtually unchanged due to rapid progression and metastasis. While N-acetyltransferase 10 (NAT10) has been identified as a regulator of mRNA acetylation in many malignancies, its role in PDAC remains unclear. Here, we found that NAT10 mRNA and protein levels were upregulated in PDAC tissues. Increased NAT10 protein expression was significantly correlated with poor prognosis in PDAC patients. Through our experiments, we demonstrated that NAT10 acted as an oncogene to promote PDAC tumorigenesis and metastasis in vitro and in vivo. Mechanistically, NAT10 exerts its oncogenic effects by promoting mRNA stability of receptor tyrosine kinase AXL in an ac4C-dependent manner leading to increased AXL expression and further promoting PDAC cell proliferation and metastasis. Together, our findings highlight the critical of NAT10 in PDAC progression and reveal a novel epigenetic mechanism by which modified mRNA acetylation promotes PDAC metastasis.

Role of NAT10-mediated ac4C-modified HSP90AA1 RNA acetylation in ER stress-mediated metastasis and lenvatinib resistance in hepatocellular carcinoma

Emerging evidence showed that epigenetic regulation plays important role in the pathogenesis of HCC. N4-acetocytidine (ac4C) was an acetylation chemical modification of mRNA, and NAT10 is reported to regulate ac4C modification and enhance endoplasmic reticulum stress (ERS) in tumor metastasis. Here, we report a novel mechanism by which NAT10-mediated mRNA ac4C-modified HSP90AA1 regulates metastasis and tumor resistance in ERS of HCC. Immunohistochemical, bioinformatics analyses, and in vitro and in vivo experiments, e.g., acRIP-Seq, RNA-Seq, and double luciferase reporter experiment, were employed to investigate the effect of NAT10 on metastasis and drug resistance in HCC. The increased expression of NAT10 was associated with HCC risk and poor prognosis. Cell and animal experiments showed that NAT10 enhanced the metastasis ability and apoptosis resistance of HCC cells in ERS and ERS state. NAT10 could upregulate the modification level of HSP90AA1 mRNA ac4C, maintain the stability of HSP90AA1, and upregulate the expression of HSP90AA1, which further promotes the metastasis of ERS hepatoma cells and the resistance to apoptosis of Lenvatinib. This study proposes a novel mechanism by which NAT10-mediated mRNA ac4C modification regulates tumor metastasis. In addition, we demonstrated the regulatory effect of NAT10-HSP90AA1 on metastasis and drug resistance of ERS in HCC cells.

NAA60 (HAT4): the newly discovered bi-functional Golgi member of the acetyltransferase family

Chromatin structural organization, gene expression and proteostasis are intricately regulated in a wide range of biological processes, both physiological and pathological. Protein acetylation, a major post-translational modification, is tightly involved in interconnected biological networks, modulating the activation of gene transcription and protein action in cells. A very large number of studies describe the pivotal role of the so-called acetylome (accounting for more than 80% of the human proteome) in orchestrating different pathways in response to stimuli and triggering severe diseases, including cancer. NAA60/NatF (N-terminal acetyltransferase F), also named HAT4 (histone acetyltransferase type B protein 4), is a newly discovered acetyltransferase in humans modifying N-termini of transmembrane proteins starting with M-K/M-A/M-V/M-M residues and is also thought to modify lysine residues of histone H4. Because of its enzymatic features and unusual cell localization on the Golgi membrane, NAA60 is an intriguing acetyltransferase that warrants biochemical and clinical investigation. Although it is still poorly studied, this review summarizes current findings concerning the structural hallmarks and biological role of this novel targetable epigenetic enzyme.