ARD1/NAA10 in hepatocellular carcinoma: pathways and clinical implications

Longitudinal adaptive behavioral outcomes in Ogden syndrome by seizure status and therapeutic intervention

Ogden syndrome, also known as NAA10-related neurodevelopmental syndrome, is a rare genetic condition associated with pathogenic variants in the NAA10 N-terminal acetylation family of proteins. The condition was initially described in 2011 and is characterized by a range of neurologic symptoms, including intellectual disability and seizures, as well as developmental delays, psychiatric symptoms, congenital heart abnormalities, hypotonia, and others. Previously published articles have described the etiology and phenotype of Ogden syndrome, mostly with retrospective analyses; herein, we report prospective data concerning its progress over time. The current study involves a total of 58 distinct participants; of these, 43 caregivers were interviewed using the Vineland-3 and answered a survey regarding therapy and other questions, 10 of whom completed the Vineland-3 but did not answer the survey, and 5 participants who answered the survey but have not yet performed the Vineland-3 due to language constraints. The average age at the time of the most recent assessment was 12.4 years, with individuals ranging in age from 11 months to 40.2 years. Using Vineland-3 scores, we show decline in cognitive function over time in individuals with Ogden syndrome (n = 53). Sub-domain analysis found the decline to be present across all modalities. In addition, we describe the nature of seizures in this condition in greater detail, as well as investigate how already-available non-pharmaceutical therapies impact individuals with NAA10-related neurodevelopmental syndrome. Additional investigation between seizure and non-seizure groups showed no significant difference in adaptive behavior outcomes. A therapy investigation showed speech therapy to be the most commonly used therapy by individuals with NAA10-related neurodevelopmental syndrome, followed by occupational and physical therapy, with more severely affected individuals receiving more types of therapy than their less-severe counterparts. Early intervention analysis was only significantly effective for speech therapy, with analyses of all other therapies being non-significant. Our study portrays the decline in cognitive function over time of individuals within our cohort, independent of seizure status, and therapies being received, and highlights the urgent need for the development of effective treatments for Ogden syndrome.

Identification of KNOP1 as a prognostic marker in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a malignancy with a poor prognosis. This study aimed to evaluate the role and molecular mechanism of lysine-rich nucleolar protein 1 (KNOP1) in HCC.

Methods

Data from The Cancer Genome Atlas (TCGA), genotype-tissue expression (GTEx), and Gene Expression Omnibus (GEO) databases were used to compare KNOP1 expression in normal and HCC tissues. The Human Protein Atlas (HPA) database was used to verify KNOP1 protein expression. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), gene set enrichment, protein-protein and gene-gene interaction network, DNA methylation, genetic alteration, and immune cell infiltration analyses were used to analyze the function and pathway enrichment of KNOP1. Finally, receiver operating characteristic (ROC) curves, Kaplan-Meier (KM) analysis, univariate/multivariate Cox regression analyses, and nomograms were used to predict the clinical and prognostic significance of KNOP1.

Results

KNOP1 expression was higher in HCC tissue samples than in normal specimens. Additionally, high KNOP1 expression was positively correlated with T helper 2 (Th2) cells and immune checkpoints. KM analysis, Cox regression analysis, and nomogram prognostic model prediction suggested that high KNOP1 expression is a risk factor for poor HCC prognosis.

Conclusions

KNOP1 overexpression is associated with poor HCC prognosis and increased proportions of immune cell infiltration and checkpoints. KNOP1 is a potential biomarker for evaluating HCC prognosis.

Naa10p promotes cell invasiveness of esophageal cancer by coordinating the c-Myc and PAI1 regulatory axis

N-α-acetyltransferase 10 protein, Naa10p, is involved in various cellular functions impacting tumor progression. Due to its capacity to acetylate a large spectrum of proteins, both oncogenic and tumor-suppressive roles of Naa10p have been documented. Here, we report an oncogenic role of Naa10p in promoting metastasis of esophageal cancer. NAA10 is more highly expressed in esophageal cancer tissues compared to normal tissues. Higher NAA10 expression also correlates with poorer survival of esophageal cancer patients. We found that NAA10 expression was transcriptionally regulated by the critical oncogene c-Myc in esophageal cancer. Furthermore, activation of the c-Myc-Naa10p axis resulted in upregulated cell invasiveness of esophageal cancer. This increased cell invasiveness was also elucidated to depend on the enzymatic activity of Naa10p. Moreover, Naa10p cooperated with Naa15p to interact with the protease inhibitor, PAI1, and prevent its secretion. This inhibition of PAI1 secretion may derive from the N-terminal acetylation effect of the Naa10p/Naa15p complex. Our results establish the significance of Naa10p in driving metastasis in esophageal cancer by coordinating the c-Myc-PAI1 axis, with implications for its potential use as a prognostic biomarker and therapeutic target for esophageal cancer.

Lysine Acetyltransferases and Their Role in AR Signaling and Prostate Cancer

The development and growth of a normal prostate gland, as well as its physiological functions, are regulated by the actions of androgens through androgen receptor (AR) signaling which drives multiple cellular processes including transcription, cellular proliferation, and apoptosis in prostate cells. Post-translational regulation of AR plays a vital role in directing its cellular activities via modulating its stability, nuclear localization, and transcriptional activity. Among various post-translational modifications (PTMs), acetylation is an essential PTM recognized in AR and is governed by the regulated actions of acetyltransferases and deacetyltransferases. Acetylation of AR has been identified as a critical step for its activation and depending on the site of acetylation, the intracellular dynamics and activity of the AR can be modulated. Various acetyltransferases such as CBP, p300, PCAF, TIP60, and ARD1 that are known to acetylate AR, may directly coactivate the AR transcriptional function or help to recruit additional coactivators to functionally regulate the transcriptional activity of the AR. Aberrant expression of acetyltransferases and their deregulated activities have been found to interfere with AR signaling and play a key role in development and progression of prostatic diseases, including prostate cancer (PCa). In this review, we summarized recent research advances aimed at understanding the role of various lysine acetyltransferases (KATs) in the regulation of AR activity at the level of post-translational modifications in normal prostate physiology, as well as in development and progression of PCa. Considering the critical importance of KATs in modulating AR activity in physiological and patho-physiological context, we further discussed the potential of targeting these enzymes as a therapeutic option to treat AR-related pathology in combination with hormonal therapy.

RPL19 Is a Prognostic Biomarker and Promotes Tumor Progression in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies, and the therapeutic outcome remains undesirable due to its recurrence and metastasis. Gene dysregulation plays a pivotal role in the occurrence and progression of cancer, and the molecular mechanisms are largely unknown.

Methods

The differentially expressed genes of HCC screened from the GSE39791 dataset were used to conduct weighted gene co-expression network analysis. The selected hub genes were validated in The Cancer Genome Atlas (TCGA) database and 11 HCC datasets from the Gene Expression Omnibus (GEO) database. Then, a tissue microarray comprising 90 HCC specimens and 90 adjacent normal specimens was used to validate the hub genes. Moreover, the Hallmark, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to identify enriched pathways. Then, we conducted the immune infiltration analysis.

Results

A total of 17 co-expression modules were obtained by weighted gene co-expression network analysis. The green, blue, and purple modules were the most relevant to HCC samples. Four hub genes, RPL19, RPL35A, RPL27A, and RPS12, were identified. Interestingly, we found that all four genes were highly expressed in HCC and that their high expression was related to a poor prognosis by analyzing the TCGA and GEO databases. Furthermore, we investigated RPL19 in HCC tissue microarrays and demonstrated that RPL19 was overexpressed in tumor tissues compared with non-tumor tissues (p = 0.016). Moreover, overexpression of RPL19 predicted a poor prognosis in hepatocellular carcinoma (p < 0.0007). Then, enrichment analysis revealed that cell cycle pathways were significantly enriched, and bile acid metabolism-related pathways were significantly down-regulated when RPL19 was highly expressed. Furthermore, immune infiltration analysis showed that immune response was suppressed.

Conclusion

Our study demonstrates that RPL19 may play an important role in promoting tumor progression and is correlated with a poor prognosis in HCC. RPL19 may serve as a promising biomarker and therapeutic target for the precise diagnosis and treatment of HCC in the future.

Oxidative Stress-Derived Mitochondrial Dysfunction in Chronic Obstructive Pulmonary Disease: A Concise Review

Chronic obstructive pulmonary disease (COPD) is a progressive and disabling disorder marked by airflow limitation and extensive destruction of lung parenchyma. Cigarette smoke is the major risk factor for COPD development and has been associated with increased oxidant burden on multiple cell types in the lungs. Elevated levels of reactive oxygen species (ROS) may significantly affect expression of biological molecules, signaling pathways, and function of antioxidant defenses. Although inflammatory cells, such as neutrophils and macrophages, contribute to the release of large quantities of ROS, mitochondrial dysfunction plays a critical role in ROS production due to oxidative phosphorylation. Although mitochondria are dynamic organelles, excess oxidative stress is able to alter mitochondrial function, morphology, and RNA and protein content. Indeed, mitochondria may change their shape by undergoing fusion (regulated by mitofusin 1, mitofusin 2, and optic atrophy 1 proteins) and fission (regulated by dynamin-related protein 1), which are essential processes to maintain a healthy and functional mitochondrial network. Cigarette smoke can induce mitochondrial hyperfusion, thus reducing mitochondrial quality control and cellular stress resistance. Furthermore, diminished levels of enzymes involved in the mitophagy process, such as Parkin (a ubiquitin ligase E3) and the PTEN-induced putative kinase 1 (PINK1), are commonly observed in COPD and correlate directly with faulty removal of dysfunctional mitochondria and consequent cell senescence in this disorder. In this review, we highlight the main mechanisms for the regulation of mitochondrial quality and how they are affected by oxidative stress during COPD development and progression.

Naa10p Enhances Chemosensitivity to Cisplatin in Oral Squamous Cell Carcinoma Cells

Background

This study aimed to investigate the function and underlying molecular mechanism of N-α-acetyltransferase 10 protein (Naa10p) in cisplatin (CDDP) chemosensitivity in oral squamous cell carcinoma (OSCC).

Methods

Salivary Naa10p levels in 76 OSCC patients undergoing CDDP-based chemotherapy were detected using enzyme-linked immunosorbent assay. Quantitative real-time polymerase chain reaction and Western blot were used to examine the expression of Naa10p in constructed CDDP-resistant OSCC cell (Cal-27/CDDP) lines and nude mouse model. In addition, the tumor volume and weight of nude mice were analyzed. Lentiviral system was employed to establish and identify OSCC cell lines with stable Naa10p interference or overexpression. MTT assay was used for drug sensitivity analysis. P-gp and Bcl-2 expression levels were tested by Western blot.

Results

Higher salivary Naa10p expression was present in the complete response/partial response group (n=46) compared to the stable disease/progressive disease group (n=30) in OSCC patients receiving chemotherapy treatment. Naa10p expression was down-regulated in Cal-27/CDDP cells and tissues. Naa10p overexpression significantly reduced the expression level of drug-resistant molecules. Naa10p was related to CDDP resistance and enhanced CDDP sensitivity in OSCC according to drug sensitivity analysis and nude mouse model experiments.

Conclusion

Naa10p plays a tumor suppressor gene role and is associated with CDDP resistance in OSCC. It can enhance CDDP sensitivity in OSCC and may be a potential target for OSCC chemotherapy.

NAA10 as a New Prognostic Marker for Cancer Progression

N-α-acetyltransferase 10 (NAA10) is an acetyltransferase that acetylates both N-terminal amino acid and internal lysine residues of proteins. NAA10 is a crucial player to regulate cell proliferation, migration, differentiation, apoptosis, and autophagy. Recently, mounting evidence presented the overexpression of NAA10 in various types of cancer, including liver, bone, lung, breast, colon, and prostate cancers, and demonstrated a correlation of overexpressed NAA10 with vascular invasion and metastasis, thereby affecting overall survival rates of cancer patients and recurrence of diseases. This evidence all points NAA10 toward a promising biomarker for cancer prognosis. Here we summarize the current knowledge regarding the biological functions of NAA10 in cancer progression and provide the potential usage of NAA10 as a prognostic marker for cancer progression.

Protein kinase C-δ interacts with and phosphorylates ARD1

Protein kinase C-δ (PKCδ) is a diacylglycerol-dependent, calcium-independent novel PKC isoform that is engaged in various cell signaling pathways, such as cell proliferation, apoptosis, inflammation, and oxidative stress. In this study, we searched for proteins that bind PKCδ using a yeast two-hybrid assay and identified murine arrest-defective 1 (mARD1) as a binding partner. The interaction between PKCδ and mARD1 was confirmed by glutathione S-transferase pull-down and co-immunoprecipitation assays. Furthermore, recombinant PKCδ phosphorylated full-length mARD1 protein. The NetPhos online prediction tool suggested PKCδ phosphorylates Ser⁸⁰ , Ser¹⁰⁸ , and Ser¹¹⁴ residues of mARD1 with the highest probability. Based on these results, we synthesized peptides containing these sites and examined their phosphorylations using recombinant PKCδ. Autoradiography confirmed these sites were efficiently phosphorylated. Consequent mass spectrometry and peptide sequencing in combination with MALDI-TOF MS/MS confirmed that Ser⁸⁰ and Ser¹⁰⁸ were major phosphorylation sites. The alanine mutations of Ser⁸⁰ and Ser¹⁰⁸ abolished the phosphorylation of mARD1 by PKCδ in 293T cells supporting these observations. In addition, kinase assays using various PKC isotypes showed that Ser⁸⁰ of ARD1 was phosphorylated by PKCβI and PKCζ isotypes with the highest selectivity, while Ser¹⁰⁸ and/or Ser¹¹⁴ were phosphorylated by PKCγ with activities comparable to that of the PKCδ isoform. Overall, these results suggest the possibility that PKCδ transduces signals by regulating phosphorylation of ARD1.

Spotlight on protein N-terminal acetylation

N-terminal acetylation (Nt-acetylation) is a widespread protein modification among eukaryotes and prokaryotes alike. By appending an acetyl group to the N-terminal amino group, the charge, hydrophobicity, and size of the N-terminus is altered in an irreversible manner. This alteration has implications for the lifespan, folding characteristics and binding properties of the acetylated protein. The enzymatic machinery responsible for Nt-acetylation has been largely described, but significant knowledge gaps remain. In this review, we provide an overview of eukaryotic N-terminal acetyltransferases (NATs) and the impact of Nt-acetylation. We also discuss other functions of known NATs and outline methods for studying Nt-acetylation.

A chemical modification of protein structure called N-terminal acetylation occurs normally in many circumstances, but is also implicated in diseases including cancers and developmental disorders. It adds an acetyl group, composed of a carbonyl group (C = O) linked to a methyl group (CH₃), to the nitrogen atom found at one end of a protein chain. Thomas Arnesen at the University of Bergen in Norway and colleagues review the understanding of this modification and survey the enzymes that carry it out. Acetylation occurs on around 80% of human proteins and affects crucial aspects of their function. These include the stability that determines proteins’ lifetimes inside cells, the three-dimensional structures that proteins fold into, and the interactions between different proteins. Advances in analytical techniques are yielding new insights into the role of N-terminal acetylation in health and disease.