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.

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.

Corosolic acid delivered by exosomes from Eriobotrya japonica decreased pancreatic cancer cell proliferation and invasion by inducing SAT1-mediated ferroptosis.

BACKGROUND: In this study, we investigated whether Exo regulate the proliferation and invasion of PC. METHODS: In this study, we isolated the Eriobotrya japonica Exo using Ultra-high speed centrifugal method. Mass spectrum were used for Exo active components analysis. PC (Capan-1 and Bxpc-3) cells proliferation, migration, and apoptosis were detected using CCK8, ethynyldeoxyuridine, transwell, wound healing, and flow cytometry analyses. We also constructed a lung metastatic mouse model and subcutaneous tumor model to illustrate the regulation effect of Exo or active components. Proteomics were used to reveal the regulatory mechanism responsible for the observed effects. RESULTS: We isolated Eriobotrya japonica Exo and found that Exo treatment significantly suppressed cell migration and proliferation in both in vivo and in vitro using Capan-1. Mass spectrum for Exo active components analysis found that Exo contains high amounts of corosolic acid (CRA). The further study found that CRA treatment inhibit the proliferation, migration, and increased cell death of both Capan-1 and Bxpc-3 cells in a concentration-dependent manner. In vivo experiments confirmed that CRA inhibited pulmonary metastasis by decreasing the number of metastatic foci. Cell proteomics analysis showed that CRA treatment induced spermidine/spermine N1-acetyltransferase 1 (SAT1)-dependent ferroptosis. Treatment with the ferroptosis suppressor ferrostatin-1 significantly reversed CRA-induced cell apoptosis. CONCLUSION: The data suggested that corosolic acid delivered by exosomes from Eriobotrya japonica decreased pancreatic cancer cell proliferation and invasion by inducing SAT1-mediated ferroptosis.

Activation of polyamine catabolism promotes glutamine metabolism and creates a targetable vulnerability in lung cancer.

Polyamines are a class of small polycationic alkylamines that play essential roles in both normal and cancer cell growth. Polyamine metabolism is frequently dysregulated and considered a therapeutic target in cancer. However, targeting polyamine metabolism as monotherapy often exhibits limited efficacy, and the underlying mechanisms are incompletely understood. Here we report that activation of polyamine catabolism promotes glutamine metabolism, leading to a targetable vulnerability in lung cancer. Genetic and pharmacological activation of spermidine/spermine N1-acetyltransferase 1 (SAT1), the rate-limiting enzyme of polyamine catabolism, enhances the conversion of glutamine to glutamate and subsequent glutathione (GSH) synthesis. This metabolic rewiring ameliorates oxidative stress to support lung cancer cell proliferation and survival. Simultaneous glutamine limitation and SAT1 activation result in ROS accumulation, growth inhibition, and cell death. Importantly, pharmacological inhibition of either one of glutamine transport, glutaminase, or GSH biosynthesis in combination with activation of polyamine catabolism synergistically suppresses lung cancer cell growth and xenograft tumor formation. Together, this study unveils a previously unappreciated functional interconnection between polyamine catabolism and glutamine metabolism and establishes cotargeting strategies as potential therapeutics in lung cancer.

The MUC1-HIF-1α signaling axis regulates pancreatic cancer pathogenesis through polyamine metabolism remodeling.

Dysregulation of polyamine metabolism has been implicated in cancer initiation and progression; however, the mechanism of polyamine dysregulation in cancer is not fully understood. In this study, we investigated the role of MUC1, a mucin protein overexpressed in pancreatic cancer, in regulating polyamine metabolism. Utilizing pancreatic cancer patient data, we noted a positive correlation between MUC1 expression and the expression of key polyamine metabolism pathway genes. Functional studies revealed that knockdown of spermidine/spermine N1-acetyltransferase 1 (SAT1), a key enzyme involved in polyamine catabolism, attenuated the oncogenic functions of MUC1, including cell survival and proliferation. We further identified a regulatory axis whereby MUC1 stabilized hypoxia-inducible factor (HIF-1α), leading to increased SAT1 expression, which in turn induced carbon flux into the tricarboxylic acid cycle. MUC1-mediated stabilization of HIF-1α enhanced the promoter occupancy of the latter on SAT1 promoter and corresponding transcriptional activation of SAT1, which could be abrogated by pharmacological inhibition of HIF-1α or CRISPR/Cas9-mediated knockout of HIF1A. MUC1 knockdown caused a significant reduction in the levels of SAT1-generated metabolites, N1-acetylspermidine and N8-acetylspermidine. Given the known role of MUC1 in therapy resistance, we also investigated whether inhibiting SAT1 would enhance the efficacy of FOLFIRINOX chemotherapy. By utilizing organoid and orthotopic pancreatic cancer mouse models, we observed that targeting SAT1 with pentamidine improved the efficacy of FOLFIRINOX, suggesting that the combination may represent a promising therapeutic strategy against pancreatic cancer. This study provides insights into the interplay between MUC1 and polyamine metabolism, offering potential avenues for the development of treatments against pancreatic cancer.

Featured lncRNA-based signature for discriminating prognosis and progression of hepatocellular carcinoma.

Long non-coding RNAs (lncRNAs) have been implicated in carcinogenesis and progression of hepatocellular carcinoma (HCC). This study aimed to identify a robust lncRNA signature for predicting the survival of HCC patients. We performed an integrated analysis of the lncRNA expression profiling in The Cancer Genome Atlas (TCGA)-liver hepatocellular carcinoma database to identify the prognosis-related lncRNA for the HCC. The HCC cohort was randomly divided into a training set (n = 250) and a testing set (n = 113). Following a two-step screening, we identified an 18-lncRNA signature risk score. The high-risk subgroups had significantly shorter survival time than the low-risk group in both the training set (P < 0.0001) and the testing set (P = 0.005). Stratification analysis revealed that the prognostic value of the lncRNA-based signature was independent of the tumor stage and pathologic stage. The area under the receiver operating characteristic curve (AUROC) of the 18-lncRNA signature risk score was 0.826 (95%CI, 0.764-0.888), 0.817 (95%CI, 0.759-0.876), and 0.799 (95%CI, 0.731-0.867) for 1-year, 3-year, and 5-year follow-up, respectively. Bioinformatics analyses indicated that the 18 lncRNA might mediate cell cycle, DNA replication processes, and canonical cancer-related pathways, in which MCM3AP-AS1 was a potential target for HCC. In conclusion, the 18-lncRNA signature was a robust predictive biomarker for the prognosis and progression of HCC.

The Arylamine N-Acetyltransferases as Therapeutic Targets in Metabolic Diseases Associated with Mitochondrial Dysfunction.

In humans, there are two arylamine N-acetyltransferase genes that encode functional enzymes (NAT1 and NAT2) as well as one pseudogene, all of which are located together on chromosome 8. Although they were first identified by their role in the acetylation of drugs and other xenobiotics, recent studies have shown strong associations for both enzymes in a variety of diseases, including cancer, cardiovascular disease, and diabetes. There is growing evidence that this association may be causal. Consistently, NAT1 and NAT2 are shown to be required for healthy mitochondria. This review discusses the current literature on the role of both NAT1 and NAT2 in mitochondrial bioenergetics. It will attempt to relate our understanding of the evolution of the two genes with biologic function and then present evidence that several major metabolic diseases are influenced by NAT1 and NAT2. Finally, it will discuss current and future approaches to inhibit or enhance NAT1 and NAT2 activity/expression using small-molecule drugs. SIGNIFICANCE STATEMENT: The arylamine N-acetyltransferases (NATs) NAT1 and NAT2 share common features in their associations with mitochondrial bioenergetics. This review discusses mitochondrial function as it relates to health and disease, and the importance of NAT in mitochondrial function and dysfunction. It also compares NAT1 and NAT2 to highlight their functional similarities and differences. Both NAT1 and NAT2 are potential drug targets for diseases where mitochondrial dysfunction is a hallmark of onset and progression.

HTATIP2 Overexpression was Associated With a Good Prognosis in Gastric Cancer.

Introduction: The purpose of this study was to compare the transcriptomes of poorly cohesive carcinoma (PCC; diffuse-type) and well-differentiated tubular adenocarcinoma (WD; intestinal-type) using gastric cancer (GC) tissues and cell lines and to evaluate the prognostic role of HIV-1 Tat Interactive Protein 2 (HTATIP2). Materials and Methods: We performed next-generation sequencing with 8 GC surgical samples (5 WD and 3 PCC) and 3 GC cell lines (1 WD: MKN74, and 2 PCC: KATOIII and SNU601). Immunohistochemistry was used to validate HTATIP2 expression. We performed functional analysis by HTATIP2 overexpression (OE). Kaplan-Meier survival plots and the PrognoScan database were used for survival analysis. Results: The genes with significantly reduced expression in PCC versus WD (in both tissues and cell lines) were HTATIP2, ESRP1, GRHL2, ARHGEF16, CKAP2L, and ZNF724. According to immunohistochemical staining, the HTATIP2-OE group had significantly higher number of patients with early GC (EGC) (T1) (P = .024), less lymph node (LN) metastasis (P = .008), and low TNMA stage (P = .017) than HTATIP2 underexpression (UE) group. Better survival rates were confirmed in the HTATIP2 OE group by Kaplan-Meir survival and PrognoScan analysis. In vitro, HTATIP2-OE in KATO III cells caused a significant decrease in cancer cell migration and invasion. Decreased Snail and Slug expression in HTATIP2 OE cells suggested that epithelial-mesenchymal transition is involved in this process. Conclusion: HTATIP2 might be a good prognostic marker and a candidate target for GC treatment.

GCN5L1-mediated acetylation prevents Rictor degradation in cardiac cells after hypoxic stress.

Cardiomyocyte apoptosis and cardiac fibrosis are the leading causes of mortality in patients with ischemic heart disease. As such, these processes represent potential therapeutic targets to treat heart failure resulting from ischemic insult. We previously demonstrated that the mitochondrial acetyltransferase protein GCN5L1 regulates cardiomyocyte cytoprotective signaling in ischemia-reperfusion injury in vivo and hypoxia-reoxygenation injury in vitro. The current study investigated the mechanism underlying GCN5L1-mediated regulation of the Akt/mTORC2 cardioprotective signaling pathway. Rictor protein levels in cardiac tissues from human ischemic heart disease patients were significantly decreased relative to non-ischemic controls. Rictor protein levels were similarly decreased in cardiac AC16 cells following hypoxic stress, while mRNA levels remained unchanged. The reduction in Rictor protein levels after hypoxia was enhanced by the knockdown of GCN5L1, and was blocked by GCN5L1 overexpression. These findings correlated with changes in Rictor lysine acetylation, which were mediated by GCN5L1 acetyltransferase activity. Rictor degradation was regulated by proteasomal activity, which was antagonized by increased Rictor acetylation. Finally, we found that GCN5L1 knockdown restricted cytoprotective Akt signaling, in conjunction with decreased mTOR abundance and activity. In summary, these studies suggest that GCN5L1 promotes cardioprotective Akt/mTORC2 signaling by maintaining Rictor protein levels through enhanced lysine acetylation.

Long noncoding RNA MCM3AP-AS1 attenuates sepsis-induced cardiomyopathy by improving inflammation, oxidative stress, and mitochondrial function through mediating the miR-501-3p/CADM1/STAT3 axis.

Oxidative stress and inflammation are highly important for sepsis-mediated myocardial damage. The long noncoding RNA (lncRNA) MCM3AP-AS1 is involved in inflammatory diseases, but its function in acute myocardial injury during sepsis has not been fully elucidated. LPS and cecal ligation and puncture (CLP) were used to construct in vitro and in vivo sepsis-induced myocardial damage models, respectively. qRT-PCR was used to evaluate alterations in MCM3AP-AS1 and miR-501-3p alterations. After the MCM3AP-AS1 and miR-501-3p knockdown or overexpression models were established, the viability, apoptosis, inflammation, oxidative stress, and mitochondrial function of the myocardial cells were examined. Dual luciferase activity assay, RNA immunoprecipitation, and fluorescence in situ hybridization (FISH) confirmed the correlation among MCM3AP-AS1, miR-501-3p, and CADM1. Previous studies revealed that MCM3AP-AS1 was downregulated in sepsis patients, myocardial cells treated with LPS, and in the CLP mouse sepsis model, whereas miR-501-3p expression was increased. MCM3AP-AS1 overexpression hampered myocardial damage mediated by LPS and abated inflammation, oxidative stress, and mitochondrial dysfunction in myocardial cells and THP-1 cells. In contrast, MCM3AP-AS1 knockdown or miR-501-3p overexpression promoted all the effects of LPS. In vivo, MCM3AP-AS1 overexpression increased the survival rate of CLP mice; ameliorated myocardial injury; decreased the levels of TNF-α, IL-1ß, IL-6, iNOS, COX2, ICAM1, VCAM1, PGE2, and MDA; and increased the levels of SOD, GSH-PX, Nrf2, and HO-1. Mechanistic studies demonstrated that MCM3AP-AS1 acted as a competitive endogenous RNA to repress miR-501-3p, enhance CADM1 expression, and dampen STAT3/nuclear factor-kappaB (NF-κB) activation. MCM3AP-AS1 suppresses myocardial injury elicited by sepsis by mediating the miR-501-3p/CADM1/STAT3/NF-κB axis.

The Effect of Silencing Fatty Acid Elongase 4 and 6 Genes on the Proliferation and Migration of Colorectal Cancer Cells.

Colorectal cancer (CRC) cells show some alterations in lipid metabolism, including an increased fatty acid elongation. This study was focused on investigating the effect of a small interfering RNA (siRNA)-mediated decrease in fatty acid elongation on CRC cells' survival and migration. In our study, the elongase 4 (ELOVL4) and elongase 6 (ELOVL6) genes were observed to be highly overexpressed in both the CRC tissue obtained from patients and the CRC cells cultured in vitro (HT-29 and WiDr cell lines). The use of the siRNAs for ELOVL4 and ELOVL6 reduced cancer cell proliferation and migration rates. These findings indicate that the altered elongation process decreased the survival of CRC cells, and in the future, fatty acid elongases can be potentially good targets in novel CRC therapy.

ESCO2 promotes hypopharyngeal carcinoma progression in a STAT1-dependent manner.

BACKGROUND: The establishment of sister chromatid cohesion N-acetyltransferase 2 (ESCO2) is involved in the development of multiple malignancies. However, its role in hypopharyngeal carcinoma (HPC) progression remains uncharacterized. METHODS: This study employed bioinformatics to determine the ESCO2 expression in head and neck squamous cell carcinoma (HNSC) and normal tissues. In vitro cell proliferation, migration, apoptosis, and/or cell cycle distribution assays were used to determine the function of ESCO2 and its relationship with STAT1. Xenograft models were established in nude mice to determine ESCO2 in HPC growth in vivo. Co-immunoprecipitation/mass spectrometry (Co-IP/MS) was conducted to identify the potential ESCO2 binding partners. RESULTS: We found that ESCO2 expression was elevated in HNSC tissues, and ESCO2 depletion suppressed tumor cell migration in vitro and inhibited tumor growth in vitro and in vivo. Co-IP/MS and immunoblotting assays revealed the interaction between ESCO2 and STAT1 in HPC cells. STAT1-overexpression compromised ESCO2-mediated suppressive effects on HPC cell proliferation, viability, and migration. CONCLUSIONS: These findings suggest that ESCO2 is crucial in promoting HPC malignant progression through the STAT1 pathway and provides novel therapeutic targets for HPC treatment.

Cytological and transcriptomic analysis to unveil the mechanism of web blotch resistance in Peanut.

BACKGROUND: Peanut is an important oil crop worldwide. Peanut web blotch is a fungal disease that often occurs at the same time as other leaf spot diseases, resulting in substantial leaf drop, which seriously affects the peanut yield and quality. However, the molecular mechanism underlying peanut resistance to web blotch is unknown. RESULTS: The cytological examination revealed no differences in the conidium germination rate between the web blotch-resistant variety ZH and the web blotch-susceptible variety PI at 12-48 hpi. The appressorium formation rate was significantly higher for PI than for ZH at 24 hpi. The papilla formation rate at 36 hpi and the hypersensitive response rate at 60 and 84 hpi were significantly higher for ZH than for PI. We also compared the transcriptional profiles of web blotch-infected ZH and PI plants at 0, 12, 24, 36, 48, 60, and 84 hpi using an RNA-seq technique. There were more differentially expressed genes (DEGs) in ZH and PI at 12, 36, 60, and 84 hpi than at 24 and 48 hpi. Moreover, there were more DEGs in PI than in ZH at each time-point. The analysis of metabolic pathways indicated that pantothenate and CoA biosynthesis; monobactam biosynthesis; cutin, suberine and wax biosynthesis; and ether lipid metabolism are specific to the active defense of ZH against YY187, whereas porphyrin metabolism as well as taurine and hypotaurine metabolism are pathways specifically involved in the passive defense of ZH against YY187. In the protein-protein interaction (PPI) network, most of the interacting proteins were serine acetyltransferases and cysteine synthases, which are involved in the cysteine synthesis pathway. The qRT-PCR data confirmed the reliability of the transcriptome analysis. CONCLUSION: On the basis of the PPI network for the significantly enriched genes in the pathways which were specifically enriched at different time points in ZH, we hypothesize that serine acetyltransferases and cysteine synthases are crucial for the cysteine-related resistance of peanut to web blotch. The study results provide reference material for future research on the mechanism mediating peanut web blotch resistance.

Indomethacin Induces Spermidine/Spermine-N1-Acetyltransferase-1 via the Nucleolin-CDK1 Axis and Synergizes with the Polyamine Oxidase Inhibitor Methoctramine in Lung Cancer Cells.

Indomethacin is a non-selective NSAID used against pain and inflammation. Although cyclooxygenase (COX) inhibition is considered indomethacin's primary action mechanism, COX-independent ways are associated with beneficial effects in cancer. In colon cancer cells, the activation of the peroxisome proliferator-activated receptor-γ (PPAR-γ) is related to the increase in spermidine/spermine-N1-acetyltransferase-1 (SSAT-1), a key enzyme for polyamine degradation, and related to cell cycle arrest. Indomethacin increases the SSAT-1 levels in lung cancer cells; however, the mechanism relying on the SSAT-1 increase is unclear. Thus, we asked for the influence of the PPAR-γ on the SSAT-1 expression in two lung cancer cell lines: H1299 and A549. We found that the inhibition of PPAR-γ with GW9662 did not revert the increase in SSAT-1 induced by indomethacin. Because the mRNA of SSAT-1 suffers a pre-translation retention step by nucleolin, a nucleolar protein, we explored the relationship between indomethacin and the upstream translation regulators of SSAT-1. We found that indomethacin decreases the nucleolin levels and the cyclin-dependent kinase 1 (CDK1) levels, which phosphorylates nucleolin in mitosis. Overexpression of nucleolin partially reverts the effect of indomethacin over cell viability and SSAT-1 levels. On the other hand, Casein Kinase, known for phosphorylating nucleolin during interphase, is not modified by indomethacin. SSAT-1 exerts its antiproliferative effect by acetylating polyamines, a process reverted by the polyamine oxidase (PAOX). Recently, methoctramine was described as the most specific inhibitor of PAOX. Thus, we asked if methoctramine could increase the effect of indomethacin. We found that, when combined, indomethacin and methoctramine have a synergistic effect against NSCLC cells in vitro. These results suggest that indomethacin increases the SSAT-1 levels by reducing the CDK1-nucleolin regulatory axis, and the PAOX inhibition with methoctramine could improve the antiproliferative effect of indomethacin.

N-acetyltransferase 10 promotes the progression of oral squamous cell carcinoma through N4-acetylcytidine RNA acetylation of MMP1 mRNA.

The pathogenesis of oral squamous cell carcinoma (OSCC) remains unclear. Therefore, clarifying its pathogenesis and molecular-level development mechanism has become the focus of OSCC research. N-acetyltransferase 10 (NAT10) is a crucial enzyme involved in mRNA acetylation, regulating target gene expression and biological functions of various diseases through mediating N4-acetylcytidine (ac4C) acetylation. However, its role in OSCC progression is not well understood. In this study, we showed that NAT10 was significantly upregulated in OSCC tissues compared to normal oral tissues. Moreover, lentivirus-mediated NAT10 knockdown markedly suppressed cell proliferation, migration, and invasion in two OSCC cell lines (SCC-9 and SCC-15). Interestingly, MMP1 was found to be significantly upregulated in OSCC tissues and was a potential target of NAT10. N-acetyltransferase 10 knockdown significantly reduced both the total and ac4C acetylated levels of MMP1 mRNA and decreased its mRNA stability. Xenograft experiments further confirmed the inhibitory effect of NAT10 knockdown on the tumorigenesis and metastasis ability of OSCC cells and decreased MMP1 expression in vivo. Additionally, NAT10 knockdown impaired the proliferation, migration, and invasion abilities in OSCC cell lines in an MMP1-dependent manner. Our results suggest that NAT10 acts as an oncogene in OSCC, and targeting ac4C acetylation could be a promising therapeutic strategy for OSCC treatment.

Multiple impacts of Naa10p on cancer progression: Molecular functions and clinical prospects.

Nα-acetyltransferase 10 protein (Naa10p) is known as the catalytic subunit of N-terminal acetyltransferases A (NatA) complex, associating with Naa15p to acetylate N-termini of the human proteome. Recent investigations have unveiled additional functions for Naa10p, encompassing lysine ε-acetylation and acetyltransferase-independent activities. Its pleiotropic roles have been implicated in diverse physiological and pathological contexts. Emerging evidence has implicated Naa10p in cancer progression, demonstrating dual attributes as an oncogene or a tumor suppressor contingent on the cancer type and acetyltransferase activity context. In this comprehensive review, we present a pan-cancer analysis aimed at elucidating the intricacies underlying Naa10p dysregulation in cancer. Our findings propose the potential involvement of c-Myc as a modulatory factor influencing Naa10p expression. Moreover, we provide a consolidated summary of recent advancements in understanding the intricate molecular underpinnings through which Naa10p contributes to cancer cell proliferation and metastasis. Furthermore, we delve into the multifaceted nature of Naa10p's roles in regulating cancer behaviors, potentially attributed to its interactions with a repertoire of partner proteins. Through an exhaustive exploration of Naa10p's functions, spanning its acetylation activity and acetyltransferase-independent functionalities, this review offers novel insights with implications for targeted therapeutic strategies involving this pivotal protein in the realm of cancer therapeutics.

Using cell lysates to assess N-terminal acetyltransferase activity and impairment.

The vast majority of eukaryotic proteins are subjected to N-terminal (Nt) acetylation. This reaction is catalyzed by a group of N-terminal acetyltransferases (NATs), which co- or post-translationally transfer an acetyl group from Acetyl coenzyme A to the protein N-terminus. Nt-acetylation plays an important role in many cellular processes, but the functional consequences of this widespread protein modification are still undefined for most proteins. Several in vitro acetylation assays have been developed to study the catalytic activity and substrate specificity of NATs or other acetyltransferases. These assays are valuable tools that can be used to define substrate specificities of yet uncharacterized NAT candidates, assess catalytic impairment of pathogenic NAT variants, and determine the potency of chemical inhibitors. The enzyme input in acetylation assays is typically acetyltransferases that have been recombinantly expressed and purified or immunoprecipitated proteins. In this chapter, we highlight how cell lysates can also be used to assess NAT catalytic activity and impairment when used as input in a previously described isotope-based in vitro Nt-acetylation assay. This is a fast and highly sensitive method that utilizes isotope labeled 14C-Ac-CoA and scintillation to detect the formation of Nt-acetylated peptide products.

Novel Long Noncoding RNAs, LINC01093 and MYLK-AS1, Serve as Potential Diagnostic and Prognostic Biomarkers or Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most fatal human malignancies worldwide. In this research, we aimed to identify long noncoding RNAs (lncRNAs) as biomarkers for HCC diagnosis and prognosis. lncRNA expression profiles were obtained from Gene Expression Omnibus and The Cancer Genome Atlas databases. The differentially expressed lncRNAs between HCC and adjacent tissues were analyzed with bioinformatic tools. Four lncRNAs with area under the curve of the receiver operating characteristic curve >0.9 were selected from both datasets. Univariate and Kaplan-Meier analyses were performed to obtain LINC01093, MYLK-AS1, and MCM3AP-AS1 as the optimal diagnostic and prognostic biomarkers. Finally, qPCR confirmed that LINC01093 and MYLK-AS1 were significantly differentially expressed in HCC and adjacent normal tissues. In general, we demonstrated that novel lncRNAs, LINC01093 and MYLK-AS1, could be used as potential diagnostic and prognostic biomarkers for HCC.

Intraparenchymal convection enhanced delivery of AAV in sheep to treat Mucopolysaccharidosis IIIC.

BACKGROUND: Mucopolysaccharidosis IIIC (MPSIIIC) is one of four Sanfilippo diseases sharing clinical symptoms of severe cognitive decline and shortened lifespan. The missing enzyme, heparan sulfate acetyl-CoA: α-glucosaminide-N-acetyltransferase (HGSNAT), is bound to the lysosomal membrane, therefore cannot cross the blood-brain barrier or diffuse between cells. We previously demonstrated disease correction in MPSIIIC mice using an Adeno-Associated Vector (AAV) delivering HGSNAT via intraparenchymal brain injections using an AAV2 derived AAV-truetype (AAV-TT) serotype with improved distribution over AAV9. METHODS: Here, intraparenchymal AAV was delivered in sheep using catheters or Hamilton syringes, placed using Brainlab cranial navigation for convection enhanced delivery, to reduce proximal vector expression and improve spread. RESULTS: Hamilton syringes gave improved AAV-GFP distribution, despite lower vector doses and titres. AAV-TT-GFP displayed moderately better transduction compared to AAV9-GFP but both serotypes almost exclusively transduced neurons. Functional HGSNAT enzyme was detected in 24-37% of a 140g gyrencephalic sheep brain using AAV9-HGSNAT with three injections in one hemisphere. CONCLUSIONS: Despite variabilities in volume and titre, catheter design may be critical for efficient brain delivery. These data help inform a clinical trial for MPSIIIC.

Epigenetic silencing of HTATIP2 in glioblastoma contributes to treatment resistance by enhancing nuclear translocation of the DNA repair protein MPG.

Glioblastoma, the most malignant brain tumor in adults, exhibits characteristic patterns of epigenetic alterations that await elucidation. The DNA methylome of glioblastoma revealed recurrent epigenetic silencing of HTATIP2, which encodes a negative regulator of importin ß-mediated cytoplasmic-nuclear protein translocation. Its deregulation may thus alter the functionality of cancer-relevant nuclear proteins, such as the base excision repair (BER) enzyme N-methylpurine DNA glycosylase (MPG), which has been associated with treatment resistance in GBM. We found that induction of HTATIP2 expression in GBM cells leads to a significant shift of predominantly nuclear to cytoplasmic MPG, whereas depletion of endogenous HTATIP2 results in enhanced nuclear MPG localization. Reduced nuclear MPG localization, prompted by HTATIP2 expression or by depletion of MPG, yielded less phosphorylated-H2AX-positive cells upon treatment with an alkylating agent. This suggested reduced MPG-mediated formation of apurinic/apyrimidinic sites, leaving behind unrepaired DNA lesions, reflecting a reduced capacity of BER in response to the alkylating agent. Epigenetic silencing of HTATIP2 may thus increase nuclear localization of MPG, thereby enhancing the capacity of the glioblastoma cells to repair treatment-related lesions and contributing to treatment resistance.