HDAC Research Articles

Polymorphisms Related to Iron Homeostasis Associate with Liver Disease in Chronic Hepatitis C.

Dysregulation of iron metabolism in chronic hepatitis C (CHC) is a significant risk factor for hepatic cirrhosis and cancer. We studied if known genetic variants related to iron homeostasis associate with liver disease progression in CHC. Retrospective analysis included 249 CHC patients qualified for antiviral therapy between 2004 and 2014. For all patients, nine SNPs within HFE, TFR2, HDAC2, HDAC3, HDAC5, TMPRSS6, and CYBRD1 genes were genotyped. Expression of selected iron-related genes, was determined with qRT-PCR in 124 liver biopsies, and mRNA expression of co-inhibitory receptors (PD-1, Tim3, CTLA4) was measured in 79 liver samples. CYBRD1 rs884409, HDAC5 rs368328, TFR2 rs7385804, and TMPRSS6 rs855791 associated with histopathological changes in liver tissue at baseline. The combination of minor allele in HDAC3 rs976552 and CYBRD1 rs884409 linked with higher prevalence of hepatocellular carcinoma (HCC) during follow up (OR 8.1 CI 2.2-29.2; p = 0.001). Minor allele in HDAC3 rs976552 associated with lower hepatic expression of CTLA4. Tested polymorphisms related to iron homeostasis associate with histopathological changes in the liver. The presence of both HDAC3 rs976552 G and CYBRD1 rs884409 G alleles correlates with HCC occurrence, especially in the group of patients with elevated AST (>129 IU/L). rs976552 in HDAC3 could impact immunological processes associated with carcinogenesis in CHC.

COPD Patients Exhibit Distinct Gene Expression, Accelerated Cellular Aging, and Bias to M2 Macrophages.

COPD, one of world's leading contributors to morbidity and mortality, is characterized by airflow limitation and heterogeneous clinical features. Three main phenotypes are proposed: overlapping asthma/COPD (ACO), exacerbator, and emphysema. Disease severity can be classified as mild, moderate, severe, and very severe. The molecular basis of inflammatory amplification, cellular aging, and immune response are critical to COPD pathogenesis. Our aim was to investigate EP300 (histone acetylase, HAT), HDAC 2 (histone deacetylase), HDAC3, and HDAC4 gene expression, telomere length, and differentiation ability to M1/M2 macrophages. For this investigation, 105 COPD patients, 42 smokers, and 73 non-smoker controls were evaluated. We identified a reduced HDAC2 expression in patients with mild, moderate, and severe severity; a reduced HDAC3 expression in patients with moderate and severe severity; an increased HDAC4 expression in patients with mild severity; and a reduced EP300 expression in patients with severe severity. Additionally, HDAC2 expression was reduced in patients with emphysema and exacerbator, along with a reduced HDAC3 expression in patients with emphysema. Surprisingly, smokers and all COPD patients showed telomere shortening. COPD patients showed a higher tendency toward M2 markers. Our data implicate genetic changes in COPD phenotypes and severity, in addition to M2 prevalence, that might influence future treatments and personalized therapies.

Fruit Extract, Rich in Polyphenols and Flavonoids, Modifies the Expression of DNMT and HDAC Genes Involved in Epigenetic Processes.

Recently, the field of epigenetics has been intensively studied in relation to nutrition. In our study, the gene expression patterns of histone deacetylases (HDACs), which regulate the stability of histone proteins, and DNA methyltransferases (DNMTs), which regulate DNA methylation, were determined in mice. The animals were fed a human-equivalent dose of the aqueous extract of fruit seeds and peels, which is rich in flavonoids and polyphenols, for 28 days and then exposed to the carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). The concentrations of trans-resveratrol and trans-piceid were determined in the consumed extract by HPLC and were 1.74 mg/L (SD 0.13 mg/L) and 2.37 mg/L (SD 0.32 mg/L), respectively, which corresponds to the consumption of 0.2-1 L of red wine, the main dietary source of resveratrol, in humans daily. Subsequently, 24 h after DMBA exposure, the expression patterns of the HDAC and DNMT genes in the liver and kidneys were determined by qRT-PCR. The DMBA-induced expression of the tested genes HDAC1, HDAC2, DNMT1, DNMT3A and DNMT3B was reduced in most cases by the extract. It has already been shown that inhibition of the DNMT and HDAC genes may delay cancer development and tumour progression. We hypothesise that the extract studied may exert chemopreventive effects.

The Australasian dingo archetype: de novo chromosome-length genome assembly, DNA methylome, and cranial morphology.

One difficulty in testing the hypothesis that the Australasian dingo is a functional intermediate between wild wolves and domesticated breed dogs is that there is no reference specimen. Here we link a high-quality de novo long-read chromosomal assembly with epigenetic footprints and morphology to describe the Alpine dingo female named Cooinda. It was critical to establish an Alpine dingo reference because this ecotype occurs throughout coastal eastern Australia where the first drawings and descriptions were completed. We generated a high-quality chromosome-level reference genome assembly (Canfam_ADS) using a combination of Pacific Bioscience, Oxford Nanopore, 10X Genomics, Bionano, and Hi-C technologies. Compared to the previously published Desert dingo assembly, there are large structural rearrangements on chromosomes 11, 16, 25, and 26. Phylogenetic analyses of chromosomal data from Cooinda the Alpine dingo and 9 previously published de novo canine assemblies show dingoes are monophyletic and basal to domestic dogs. Network analyses show that the mitochondrial DNA genome clusters within the southeastern lineage, as expected for an Alpine dingo. Comparison of regulatory regions identified 2 differentially methylated regions within glucagon receptor GCGR and histone deacetylase HDAC4 genes that are unmethylated in the Alpine dingo genome but hypermethylated in the Desert dingo. Morphologic data, comprising geometric morphometric assessment of cranial morphology, place dingo Cooinda within population-level variation for Alpine dingoes. Magnetic resonance imaging of brain tissue shows she had a larger cranial capacity than a similar-sized domestic dog. These combined data support the hypothesis that the dingo Cooinda fits the spectrum of genetic and morphologic characteristics typical of the Alpine ecotype. We propose that she be considered the archetype specimen for future research investigating the evolutionary history, morphology, physiology, and ecology of dingoes. The female has been taxidermically prepared and is now at the Australian Museum, Sydney.

Liver tissues oxidative status, epigenetic and molecular characteristics in rats administered magnetic and microwave treated water

Physical and chemical changes in the natural of water may affect biological organisms. In this study, we highlight the effect of magnetized-water and microwave-water on rats’ liver tissues. Three groups of albino rats were separated. The first, rats were administered tap-water. The second, rats were administered magnetized-water. The third, rats were administered microwave-water. After two months, the results revealed a significant increase in liver functioning enzymes’ levels and bilirubin in rats administered microwave-water, compared to tap- and magnetic-water. In relation to oxidative stress, there was a significant increase and decrease in oxidative and antioxidant parameters respectively in liver tissues of rat's administrated microwave-water. At the molecular level, there was a significant down-regulation in Metallothionein, CYP genes in magnetic-water compared to tap-water. Rats administered microwave-water have shown a significant down-regulation in GST, Metallothionein and CYP genes’ expression, however, Amylase and HDAC3 genes were significantly up-regulated, compared to the other groups. The intake of microwave-water resulted in notable histopathological changes in liver tissues. Rats administered magnetic-water showed no clear changes in their liver tissues. In summary, microwave-water induced stress and epigenetic effects compared with magnetic-water and tap-water. Also, magnetic-water produced from the higher magnetic power had no side effect on liver tissues.

Histone Deacetylase 6 Inhibitor CKD-WID Suppressed Monosodium Urate-Induced Osteoclast Formation by Blocking Calcineurin-NFAT Pathway in RAW 264.7 Cells

Histone deacetylase (HDAC) has been found to play a crucial role in the regulation of osteoclast differentiation and formation. This study was designed to identify the effect of the HDAC6 inhibitor CKD-WID on the receptor for the activation of nuclear factor-κB ligand (RANKL)-mediated osteoclast formation in the presence of monosodium urate (MSU) in RAW 264.7 murine macrophage cells. The expression of osteoclast-specific target genes, calcineurin, and nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) was evaluated in RAW 264.7 murine macrophages treated with MSU, RANKL, or CKD-WID by real-time quantitative polymerase chain reaction and Western blot assay. The effect of CKD-WID on osteoclast formation was measured by tartrate-resistant acid phosphatase (TRAP) staining, F-actin ring formation staining, and assays for bone resorption activity. RANKL in the presence of MSU significantly induced HDAC6 gene and protein expression in RAW 264.7 cells. CKD-WID markedly suppressed the expression of osteoclast-related markers such as c-Fos, TRAP, cathepsin K, and carbonic anhydrase II induced by co-stimulation with RANKL and MSU in RAW 264.7 cells. Transcription factor NFATc1 mRNA expression and nuclear NFATc1 protein expression induced by co-stimulation with RANKL and MSU were significantly inhibited by CKD-WID treatment. CKD-WID also decreased the number of TRAP-positive multinuclear cells and F-actin ring-positive cells and attenuated bone resorption activity. Co-stimulation with RANKL and MSU increased calcineurin gene and protein expression, which was significantly blocked by CKD-WID treatment. The HDAC6 inhibitor CKD-WID suppressed MSU-induced osteoclast formation through blocking the calcineurin-NFAT pathway in RAW 264.7 cells. This suggests that HDAC6 is considered a therapeutic target in uric acid-mediated osteoclastogenesis.

Epigenome alterations in food allergy: A systematic review of candidate gene and epigenome-wide association studies.

The aim of this study was to systematically review the evidence across studies that assessed DNA methylome variations in association with food allergy (FA). A systematic review of the literature and meta-analysis were carried out within several databases. However, the risk of bias in the included articles was not evaluated. PubMed, Cochrane Database of Systematic Reviews,and Web of Science were used to search up to July 2022. We included targeted and epigenome-wide association studies (EWASs) that assessed DNA methylome alterations in association with FA in adult or paediatric populations. Among 366 publications, only 16 were retained, which were mainly focused on FA in children. Seven candidate gene-targeted studies found associations in Th1/Th2 imbalance (IL4, IL5, IL10, INFG, IL2 and IL12B genes), regulatory T cell function (FOXP3 gene), Toll-like receptors pathway (TLR2, CD14 genes) and digestive barrier integrity (FLG gene). Nine EWAS assessed the association with peanut allergy (n=3), cow's milk allergy (n=2) or various food allergens (n=4). They highlighted 11 differentially methylated loci in at least two studies (RPS6KA2, CAMTA1, CTBP2, RYR2, TRAPPC9, DOCK1, GALNTL4, HDAC4, UMODL1, ZAK and TNS3 genes). Among them, CAMTA1 and RPS6KA2, and CTBP2 are involved in regulatory T cell function and Th2 cell differentiation, respectively. Gene-functional analysis revealed two enriched gene clusters involved in immune responses and protein phosphorylation. ChIP-X Enrichment Analysis 3 showed eight significant transcription factors (RXRA, ZBTB7A, ESR1, TCF3, MYOD1, CTCF, GATA3 and CBX2). Ingenuity Pathway Analysis identified canonical pathways involved, among other, in B cell development, pathogen-induced cytokine storm signalling pathway and dendritic cell maturation. This review highlights the involvement of epigenomic alterations of loci in Th1/Th2 and regulatory T cell differentiation in both candidate gene studies and EWAS. These alterations provide a better insight into the mechanistic aspects in FA pathogenesis and may guide the development of epigenome-based biomarkers for FA.

Behavior, BDNF and epigenetic mechanisms in response to social isolation and social support in middle aged rats exposed to chronic stress

Social deprivation can be stressful for group-living mammals. On the other hand, an amazing response of these animals to stress is seeking social contact to give and receive joint protection in threatening situations. We explored the effects of social isolation and social support on epigenetic and behavioral responses to chronic stress. More specifically, we investigated the behavioral responses, corticosterone levels, BDNF gene expression, and markers of hippocampal epigenetic alterations (levels of H3K9 acetylation and methylation, H3K27 methylation, HDAC5, DNMT1, and DNMT3a gene expressions) in middle-aged adult rats maintained in different housing conditions (isolation or accompanied housing) and exposed to the chronic unpredictable stress protocol (CUS). Isolation was associated with decreased basal levels of corticosterone, impaired long-term memory, and decreased expression of the BDNF gene, besides altering the balance of H3K9 from acetylation to methylation and increasing the DNMT1 gene expression. The CUS protocol decreased H3K9 acetylation, besides increasing H3K27 methylation and DNMT1 gene expression, but had no significant effects on memory and BDNF gene expression. Interestingly, the effects of CUS on corticosterone and HDAC5 gene expression were seen only in isolated animals, whereas the effects of CUS on DNMT1 gene expression were more pronounced in isolated than accompanied animals. In conclusion, social isolation in middle age showed broader effects than chronic unpredictable stress on behavioral and epigenetic alterations potentially associated with decreased BDNF expression. Moreover, social support prevented the adverse effects of CUS on HPA axis functioning, HDAC5, and DNMT1 gene expressions.

Endurance training changes the expression of miR-1 and miR-133 and predicted genes in slow and fast twitch muscles

Purpose of the researchEndurance training can modify signaling and gene expression pathways that play a pivotal role in determining the phenotype of the fibers. The present study aimed to investigate the effects of endurance training on the expression of some myomiRs and related genes in slow and fast twitch muscles. MethodsTwenty healthy male adult Wistar rats (281 ± 14 g) were randomized to either control (n = 10) or treated (n = 10). The treated group performed an endurance program for eight weeks (running on a treadmill for eight weeks, 50 min, 23 m/min). After the end of the training protocol, the slow (soleus) and fast (EDL) twitch muscles were removed to assess the miR-1, miR-133 expression, and hdac4, mef2c genes, and protein by real-time PCR and western blot, respectively. ResultsThe soleus muscle miR-1 expression and mef2c gene in the treated group were significantly lower compared control (p = 0.0001). In contrast, miR-133 and hdac4 gene expression of the soleus muscle of the treated group increased significantly (p = 0001), and the EDL miR-133 and mef2c expression of the treated group increased in the compared control group (p = 0.0001). The EDL MEF2c protein expression in the treated group significantly decreased compared to the control group, although the expression of EDL HDAC4 protein significantly increased (p = 0.0001). ConclusionsEndurance training changes the expression of the miR-1, miR-133, and their predicted genes in slow and fast twitch muscles. Also, the rate of HDAC4 and MEF2c protein synthesis, which are upstream and downstream of these myomiRs, was affected by endurance training.

Analysis of genotypes and phenotypes of three children with Cornelia de Lange syndrome

To analyze the clinical phenotype and results of genetic testing in three children with Cornelia de Lange syndrome (CdLS). Clinical data of the children and their parents were collected. Peripheral blood samples of the pedigrees were collected for next generation sequencing analysis. The main clinical manifestations of the three children have included growth delay, mental retardation, peculiar facies and other accompanying symptoms. Based on the criteria proposed by the International Diagnostic Consensus, all three children were suspected for CdLS. As revealed by whole exome sequencing, child 1 has harbored NIPBL gene c.5567_5569delGAA insTAT missense variant, child 2 has harbored SMC1A gene c.607A>G missense variant, and child 3 has harbored HDAC8 gene c.628+1G>A splicing variant. All of the variants were de novo in origin. All of the children were diagnosed with CdLS due to pathogenic variants of the associated genes, among which the variants of NIPBL and HDAC8 genes were unreported previously. Above finding has enriched the spectrum of pathogenic variants underlying CdLS.

A CRISPR/Cas9-mediated screen identifies determinants of early plasma cell differentiation.

The differentiation of B cells into antibody-secreting plasma cells depends on cell division-coupled, epigenetic and other cellular processes that are incompletely understood. We have developed a CRISPR/Cas9-based screen that models an early stage of T cell-dependent plasma cell differentiation and measures B cell survival or proliferation versus the formation of CD138+ plasmablasts. Here, we refined and extended this screen to more than 500 candidate genes that are highly expressed in plasma cells. Among known genes whose deletion preferentially or mostly affected plasmablast formation were the transcription factors Prdm1 (BLIMP1), Irf4 and Pou2af1 (OBF-1), and the Ern1 gene encoding IRE1a, while deletion of XBP1, the transcriptional master regulator that specifies the expansion of the secretory program in plasma cells, had no effect. Defective plasmablast formation caused by Ern1 deletion could not be rescued by the active, spliced form of XBP1 whose processing is dependent on and downstream of IRE1a, suggesting that in early plasma cell differentiation IRE1a acts independently of XBP1. Moreover, we newly identified several genes involved in NF-kB signaling (Nfkbia), vesicle trafficking (Arf4, Preb) and epigenetic regulators that form part of the NuRD complex (Hdac1, Mta2, Mbd2) to be required for plasmablast formation. Deletion of ARF4, a small GTPase required for COPI vesicle formation, impaired plasmablast formation and blocked antibody secretion. After Hdac1 deletion plasmablast differentiation was consistently reduced by about 50%, while deletion of the closely related Hdac2 gene had no effect. Hdac1 knock-out led to strongly perturbed protein expression of antagonistic transcription factors that govern plasma cell versus B cell identity (by decreasing IRF4 and BLIMP1 and increasing BACH2 and PAX5). Taken together, our results highlight specific and non-redundant roles for Ern1, Arf4 and Hdac1 in the early steps of plasma cell differentiation.

A New Insight Into p53-Inhibiting Genes in Epstein–Barr Virus-Associated Gastric Adenocarcinoma

The p53 mutation is uncommon in Epstein–Barr virus-linked gastric carcinoma, but its suppression occurs through mechanisms such as ubiquitin specific peptidase 7 (USP7) inhibitions via Epstein–Barr virus nuclear antigen-1 (EBNA1) activity. This study aimed to evaluate the effect of EBNA1 on p53-inhibiting gene expression and the impact of USP7 inhibition on p53 suppression. MKN-45 cells were transfected with the EBNA1 plasmid. A stable EBNA1 expression cell line was developed through selection based on hygromycin B resistance. Murine double minute (MDM)4, MDM2, sirtuin (SIRT)3, histone deacetylase (HDAC)1, proteasome 26S subunit, Non-ATPase (PSMD)10, USP7, and p53 expression were checked using real-time PCR. Also, cells containing EBNA1 or control plasmid were treated with GNE-6776, and the expression of the interested genes and cell survival were assessed. MDM4, MDM2, and PSMD10 were significantly upregulated in the MKN-45 cell line following EBNA1 transfection. Morphological changes were observed in the cells harboring EBNA1 after 20 days. In the control cells, USP7 inhibition significantly upregulated the HDAC1, PSMD10, MDM4, and MDM2 genes after 24 h, but downregulated these genes after four days. In the EBNA1-harboring cells, MDM2, MDM4, and PSMD10 genes were significantly upregulated after 24 h, and this effect was sustained for all genes except for MDM4, even after four days. Furthermore, USP7 inhibition induced apoptosis in both cell groups. EBNA1 enhances the expression of p53-inhibiting genes. Two events—p53 protein overexpression and apoptosis activation—followed the suppression of the USP7 protein and provided evidence for its possible function. The significance of the EBNA1-USP7 interaction in p53 suppression warrants additional investigation and possibly reconsideration.

Integrating Genome-Wide Association Study with RNA-Sequencing Reveals HDAC9 as a Candidate GeneInfluencing Loin Muscle Area in Beijing Black Pigs.

Loin muscle area (LMA) is an important meat production trait and plays a key role in determining carcass leanness. Genome-wide association study (GWAS) and RNA sequencing (RNA-seq) analysis were used to identify candidate LMA genes in Beijing Black pigs, a popular breed among consumers in northern China. Ten single nucleotide polymorphisms (SNPs) in sus scrofa chromosome (SSC) 9 were significantly associated with LMA. These SNPs were mapped to a 2.90 Mb (84.94-87.84 Mb) region. A total of 11 annotated genes were mapped on this region, namely MEOX2, CRPPA, SOSTDC1, LRRC72, ANKMY2, BZW2, TSPAN13, AGR2, AHR, SNX13, and HDAC9. In addition, RNA-seq analysis was performed between the high- and low-LMA groups, and 329 differentially expressed genes (DEGs) were identified. Further, Kyoto Encyclopedia of Genes and Genomes analysis based on DEGs revealed that the JAK/STAT signaling pathway and oxytocin signaling pathway may be responsible for LMA. Both GWAS and RNA-seq analysis identified the HDAC9 gene, indicating that it may be an important candidate gene affecting LMA in Beijing Black pigs. The findings provide valuable molecular insights into the mechanisms that influence LMA content in pigs, which can be utilized in targeted approaches to enhance meat quality and commercial profitability.

Prenatal Dexamethasone Exposure in Male Rats Alters Gene Expression Patterns of Epigenetic Enzymes in Hippocampus and Cortex

Objective: This study aimed to examine the effects of prenatal stress (PS) induced by dexamethasone exposure on gene expression levels of epigenetic enzymes in hippocampus and cerebral cortex of male rats through relative mRNA levels of histone acetyltransferases (activating transcription factor 2, P300), histone deacetylases (HDAC1, HDAC2), and DNA methyltransferases (DNMT1, DNMT3a, DNMT3b). Methods: Pregnant rats were daily injected subcutaneously with dexamethasone (0.2 mg/kg) or saline during the third week of gestation. After birth, male rats were killed at 90 days of age (n = 5 for control and dexamethasone groups). Hippocampal and cortical tissues were used for gene expression analyses. The effects of dexamethasone on epigenetic mechanisms were investigated by real-time polymerase chain reaction through relative mRNA levels of DNMT1, DNMT3a, DNMT3b, activating transcription factor 2, P300, HDAC1, and HDAC2. Statistical comparisons were performed with Student’s t-test. Results: Prenatal dexamethasone exposure (PDE) caused increased DNMT1, DNMT3a, DNMT3b, activating transcription factor 2 and decreased P300 mRNA levels in hippocampus while increased DNMT3a, DNMT3b, activating transcription factor 2, P300, HDAC1, and HDAC2 mRNA levels were achieved in cortex. Furthermore, no significant differences were obtained in cortical DNMT1 and hippocampal HDAC1 and HDAC2 gene expression levels between control and prenatally stressed rats. Conclusion: Our results emphasize the effect of prenatal dexamethasone exposure on gene expression levels of epigenetic enzymes involved in histone acety latio n/dea cetyl ation and DNA methylation in male rats and suggest that prenatal stress may lead to epigenetic dysregulation through alterations in hippocampal and cortical gene expression patterns of DNMT1, DNMT3a, DNMT3b, activating transcription factor 2, P300, HDAC1, and HDAC2.

Identification of Epigenetic Interactions between miRNA and Gene Expression as Potential Prognostic Markers in Bladder Cancer.

Purpose: To identify the role of a set of microRNAs and their target genes and protein expression levels in the pathogenesis of bladder cancer with a muscular invasion (T2–T4) and non-muscular invasion (T1). Methods: In 157 patients, bladder specimen was examined for the expression of a set of miRNAs including let-7a-5p, miRNA-449a-5p, miRNA-145-3P, miRNA-124-3P, miRNA-138-5p, and miRNA-23a-5p and their targeted genes; β-catenin, WNT7A, IRS2, FZD4, SOS1, HDAC1, HDAC2, HIF1α, and PTEN using the qRT-PCR technique. The prognostic effect of miRNAs and their targeted genes on cancer-specific survival (CSS) was evaluated in pT2–pT4 stages. Results: pT1 was found in 40 patients while pT2–4 was found in 117 patients. The expression of let-7a-5P, miR-124-3P, miR-449a-5P, and miR-138-5P significantly decreased in pT2–4 compared with pT1 (p < 0.001), in contrast, miR-23a-5P increased significantly in pT2–pT4 compared with pT1 (p < 0.001). Moreover, the expression of miR-145 did not show a significant change (p = 0.31). Higher expression levels of WNT7A, β-catenin, IRS2, FZD4, and SOS1 genes were observed in pT2–pT4 compared with pT1, whereas HDAC1, HDAC2, HIF1α, and PTEN genes were downregulated in pT2–pT4 compared with pT1. Lower CSS was significantly associated with lower expression of let-7a-5P, miR-124-3P, miR-449a-5P, and miR-138-5P. Higher expression of β-catenin, FZD4, IRS2, WNT7a, and SOS1 was significantly associated with worse CSS. In contrast, lower levels of HDAC1, HDAC2, HIF1α, and PTEN were associated with lower CSS. Conclusion: Our results support let-7a-5P, miR-124-3P, miR-138-5P, and their target genes can be developed as accurate biomarkers for prognosis in bladder cancer with a muscular invasion.

HDAC6 inhibition decreases leukemic stem cell expansion driven by Hedgehog hyperactivation by restoring primary ciliogenesis

Aberrant activation of the Hh pathway promotes cell proliferation and multi-drug resistance (MDR) in several cancers, including Acute Myeloid Leukemia (AML). Notably, only one Hh inhibitor, glasdegib, has been approved for AML treatment, and most patients eventually relapse, highlighting the urgent need to discover new therapeutic targets. Hh signal is transduced through the membrane of the primary cilium, a structure expressed by non-proliferating mammalian cells, whose stabilization depends on the activity of HDAC6. Here we describe a positive correlation between Hh, HDAC6, and MDR genes in a cohort of adult AML patients, human leukemic cell lines, and a zebrafish model of Hh overexpression. The hyper-activation of Hh or HDAC6 in zebrafish drove the increased proliferation of hematopoietic stem and progenitor cells (HSPCs). Interestingly, this phenotype was rescued by inhibition of HDAC6 but not of Hh. Also, in human leukemic cell lines, a reduction in vitality was obtained through HDAC6, but not Hh inhibition. Our data showed the presence of a cross-talk between Hh and HDAC6 mediated by stabilization of the primary cilium, which we detect for the first time in zebrafish HSPCs. Inhibition of HDAC6 activity alone or in combination therapy with the chemotherapeutic agent cytarabine, efficiently rescued the hematopoietic phenotype. Our results open the possibility to introduce HDAC6 as therapeutic target to reduce proliferation of leukemic blasts in AML patients.

Bioinformatics Analysis of Hub Genes Involved in Alcohol-Related Hemifacial Microsomia Pathogenesis.

Alcohol is a recognized teratogen, and alcohol exposure increases the risk for hemifacial microsomia (HFM) of the fetus during maternal pregnancy. The present study aimed to explore potential mechanisms and verify hub genes of HFM associated with alcohol by bioinformatics methods. First, HFM and alcohol pathogenic genes were obtained. Thereafter, a protein-protein interactional (PPI) network was constructed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses and molecular complex detection were performed by Metascape. Finally, we used the cytoHubba plugin to screen the hub genes. A total of 43 HFM genes and 50 optimal alcohol candidate genes were selected. The PPI networks for pathogenic genes contained 93 nodes and 503 edges. Functional enrichment analysis largely focused on tissue formation and development. Two modules were identified from the PPI network, and 10 hub genes were screened out. The genes most relevant to alcohol-induced HFM pathogenesis included CTNNB1, TP53, MYC, HDAC1, and SOX2. This study identified some significant hub genes, pathways, and modules of HFM related to alcohol by bioinformatics analyses. Our results suggest that the CTNNB1, TP53, MYC, HDAC1, and SOX B1 gene subfamilies may have played a major role in alcohol-induced HFM.

Screening of Proliferation-Related Genes and Pathological Changes in Thiram-Induced Tibial Dyschondroplasia.

Materials and Methods Three hundred sixty (n = 360) broiler chickens were equally divided into control (C) and thiram (T) groups. Furthermore, the C and T groups were dividedinto 8-, 9-, 11-, and 13-day-old chickens. Results Clinically, it was observed that broiler chickens of group T had abnormal posture, gait, and lameness, and histopathological results revealed dead and abnormal chondrocytes of T group on day 6. Real-time qPCR results showed that HDAC1, MTA1, H4, and PCNA genes were significantly expressed (P < 0.05). HDAC1 was upregulated on days 1, 2, 4, and 6 (P < 0.01); MTA1 was upregulated on days 1 and 2 (P < 0.01); H4 was upregulated on days 2 and 4 (P < 0.01), and PCNA was downregulated on days 1, 2, and 4 (P < 0.01). Furthermore, IHC results of HDAC1 protein were significantly (P < 0.01) expressed in proliferative zone of day 1 and hypertrophic zone of day 6. MTA1 protein was significantly (P < 0.01) expressed on days 1, 2, and 6 in all zones, except prehypertrophic zone of day 2. Conclusion In conclusion, the mRNA expressions of HDAC1, MTA1, H4, and PCNA were differentially expressed in the chondrocytes of thiram-induced TD chickens. HDAC1 and MTA1 protein expression found involved and responsible in the abnormal chondrocytes' proliferation of broiler chicken.

Abstract 52: Analytical validation of the Resolution HRD plasma assay used to identify mCRPC patients with mutations, including homozygous deletions, in DNA repair genes as a companion diagnostic for niraparib

Abstract Tumor cells of metastatic castration-resistant prostate cancer (mCRPC) patients with homologous recombination deficiency (HRD) are highly sensitive to the blockade of DNA single-strand break repair via the inhibition of the poly(adenosine diphosphate-ribose) polymerase (PARP) family of nuclear proteins. Niraparib is a highly selective PARP inhibitor, with activity against PARP-1/2 DNA-repair polymerases, and the Resolution HRD assay is being developed as a companion diagnostic for niraparib. Detection of HRD in cell free DNA (cfDNA) isolated from blood is minimally invasive and is of special benefit to mCRPC patients, many without accessible lesions. The Resolution HRD assay identifies patients with substitutions, insertions, deletions, and homozygous deletions of the ATM, BRCA1, BRCA2, BRIP1, CDK12 (except homozygous deletions), CHEK2, FANCA, HDAC2, and PALB2 genes by targeted NGS sequencing of cfDNA isolated from plasma. Analytical performance of the Resolution HRD assay was validated using cfDNA from mCRPC patient plasma, cfDNA from healthy donor plasma, and contrived samples with a wide spectrum of technically challenging genetic aberrations along with CRISPR-engineered human cell lines with ATM and BRCA2 gene deletions. The LOD95 was established for substitutions, insertions, deletions, and homozygous deletions for genes represented in the HRD panel with variant types including complex indels, long indels, and challenging genomic settings including homopolymeric and GC-rich regions. mCRPC specimens were used to confirm an acceptable level of precision near 1X LOD and 2-3X LOD concentrations for all 4 variant types. No false-positives were detected in any samples from healthy donors. Resolution HRD has been validated to give consistent results across the 15-30 ng input range. Studies to confirm accuracy of the Resolution HRD test results using a validated orthogonal method will be presented. The Resolution HRD assay offers highly sensitive, specific, and robust test results, and meets analytical requirements for clinical applications. It is intended as a companion diagnostic to niraparib in combination with abiraterone acetate plus prednisone (AAP) for the treatment of mCRPC patients. Citation Format: Julia Pollak, Kristy Potts, PuiYee Chan, Chen-Hsun Tsai, Angela Liao, Carly Garrison, Taylor Brown, Paul Stull, Zhen Li, Christine Baker, Kavita Garg, Ira Pekker, Michael Farabaugh, Michael Gormley, Lesley Farrington, Katherine Bell, Usha Singh. Analytical validation of the Resolution HRD plasma assay used to identify mCRPC patients with mutations, including homozygous deletions, in DNA repair genes as a companion diagnostic for niraparib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 52.

Gene-by-gene analysis in the MAGNITUDE study of niraparib (NIRA) with abiraterone acetate and prednisone (AAP) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) gene alterations.

5020 Background: NIRA + AAP significantly improved outcomes in pts with mCRPC and HRR gene alterations in the Phase 3 MAGNTUDE study. There is a paucity of data supporting use of PARP inhibitors in pts with HRR gene alterations other than BRCA1/2. We report on the efficacy of NIRA + AAP in pts with mCRPC and a qualifying single gene HRR alteration other than BRCA1/2. Methods: A pre-specified analysis was undertaken of the primary endpoint (radiographic progression-free survival [rPFS] by BICR), secondary endpoints (time to cytotoxic chemotherapy [TCC], time to symptomatic progression [TSP], overall survival [OS]), as well as time to PSA progression (TPSA) and overall response rate (ORR) across 186 pts (91 randomized to NIRA + AAP, 95 to PBO + AAP) with an alteration in the ATM, BRIP1, CDK12, CHEK2, FANCA, HDAC2, or PALB2 gene (excluding cooccurring alterations) . This analysis of individual alterations was not powered for formal statistical inference. Given the rarity of some alterations, groups based on functional similarity are also presented. Results: (Table). Pts with PALB2 or CHEK2 alterations had consistent improvement across all endpoints. In pts with ATM alterations benefit was observed in TCC, TSP, TPSA and ORR. There was benefit only in TPSA and ORR for pts with CDK12 alterations. When combined into functional groups, pts with an alteration in the HRR-Fanconi pathway ( BRIP1, FANCA, and PALB2) as well as pts with a HRR associated alteration ( CHEK2 or HDAC2) showed improvement in all endpoints. Conclusions: These data support the overall conclusions of the MAGNITUDE primary analysis and support benefit of NIRA + AAP in pts with HRR mutations beyond BRCA1/2. Clinical trial information: NCT03748641. [Table: see text]