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Cancers May 2024Bromodomain and extra-terminal (BET) domain proteins that bind to acetylated lysine residues of histones serve as the "readers" of DNA acetylation. BRD4 is the most...
BACKGROUND
Bromodomain and extra-terminal (BET) domain proteins that bind to acetylated lysine residues of histones serve as the "readers" of DNA acetylation. BRD4 is the most thoroughly studied member of the BET family and regulates the expression of key oncogenes. BRD4 gene amplification has been identified in ovarian cancer (~18-19%) according to (TCGA) analysis. BET inhibitors are novel small molecules that displace BET proteins from acetylated histones and are currently tested in Phase I/II trials. We here aim to explore the prognostic role of the BRD4 gene and protein expression in the ascitic fluid of patients with advanced FIGO III/IV high-grade serous ovarian carcinoma (HGSC).
METHODS
Ascitic fluid was obtained from 28 patients with advanced stage (FIGO III/IV) HGSC through diagnostic/therapeutic paracentesis or laparoscopy before the initiation of chemotherapy. An amount of ~200 mL of ascitic fluid was collected from each patient and peripheral blood mononuclear cells () were isolated. Each sample was evaluated for BRD4 and GAPDH gene expression through RT-qPCR and BRD4 protein levels through enzyme-linked immunosorbent assay (ELISA). The study protocol was approved by the Institutional Review Board of Alexandra University Hospital and the Committee on Ethics and Good Practice (CEGP) of the National and Kapodistrian University of Athens (NKUA).
RESULTS
Low BRD4 gene expression was associated with worse prognosis at 12 months compared to intermediate/high expression (95% CI; 1.75-30.49; = 0.008). The same association was observed at 24 months although this association was not statistically significant (95% CI; 0.96-9.2; = 0.065). Progression-free survival was shorter in patients with low BRD4 gene expression at 12 months (5.6 months; 95% CI; 2.6-8.6) compared to intermediate/high expression (9.8 months; 95% CI; 8.3-11.3) (95% CI; 1.2-16.5; = 0.03). The same association was confirmed at 24 months (6.9 months vs. 13.1 months) (95% CI; 1.1-8.6; = 0.048). There was a trend for worse prognosis in patients with high BRD4 protein levels versus intermediate/low BRD4 protein expression both at 12 months (9.8 months vs. 7.6 months; = 0.3) and at 24 months (14.2 months vs. 16.6 months; = 0.56) although not statistically significant. Again, there was a trend for shorter PFS in patients with high BRD4 protein expression although not statistically significant both at 12 months ( = 0.29) and at 24 months ( = 0.47).
CONCLUSIONS
There are contradictory data in the literature over the prognostic role of BRD4 gene expression in solid tumors. In our study, intermediate/high BRD4 gene expression was associated with a favorable prognosis in terms of overall survival and progression-free survival compared to low BRD4 gene expression.
PubMed: 38893083
DOI: 10.3390/cancers16111962 -
International Journal of Molecular... Jun 2024Post-translational modifications (PTMs) are essential for regulating protein functions, influencing various fundamental processes in eukaryotes. These include, but are... (Review)
Review
Post-translational modifications (PTMs) are essential for regulating protein functions, influencing various fundamental processes in eukaryotes. These include, but are not limited to, cell signaling, protein trafficking, the epigenetic control of gene expression, and control of the cell cycle, as well as cell proliferation, differentiation, and interactions between cells. In this review, we discuss protein PTMs that play a key role in the malaria parasite biology and its pathogenesis. Phosphorylation, acetylation, methylation, lipidation and lipoxidation, glycosylation, ubiquitination and sumoylation, nitrosylation and glutathionylation, all of which occur in malarial parasites, are reviewed. We provide information regarding the biological significance of these modifications along all phases of the complex life cycle of spp. Importantly, not only the parasite, but also the host and vector protein PTMs are often crucial for parasite growth and development. In addition to metabolic regulations, protein PTMs can result in epitopes that are able to elicit both innate and adaptive immune responses of the host or vector. We discuss some existing and prospective results from antimalarial drug discovery trials that target various PTM-related processes in the parasite or host.
Topics: Protein Processing, Post-Translational; Life Cycle Stages; Humans; Animals; Protozoan Proteins; Plasmodium; Malaria; Host-Parasite Interactions
PubMed: 38892332
DOI: 10.3390/ijms25116145 -
International Journal of Molecular... May 2024This study investigated the effects of rumen bypass dandelion extract on the lactation performance, immune index, and mammary oxidative stress of lactating dairy cows...
This study investigated the effects of rumen bypass dandelion extract on the lactation performance, immune index, and mammary oxidative stress of lactating dairy cows fed a high-concentrate diet. This study used a complete randomized block design, and initial milk production, somatic cell counts, and parities were set as block factors. Sixty Holstein cows with similar health conditions and lactating periods (70 ± 15 d) were divided into three groups with 20 replicates per group. The treatments included the LCD group (low-concentrate diet, concentrate-forage = 4:6), HCD group (high-concentrate group, concentrate-forage = 6:4), and DAE group (dandelion aqueous extract group, HCD group with 0.5% DAE). The experimental period was 35 d, and cows were fed three times in the morning, afternoon, and night with free access to water. The results showed the following: (1) Milk production in the HCD and DAE groups was significantly higher ( < 0.05) than that in the LCD group from WK4, and the milk quality differed during the experimental period. (2) The HCD group's pH values significantly differed ( 0.01) from those of the LCD and DAE groups. (3) In WK2 and WK4 of the experimental period, the somatic cell counts of dairy cows in the HCD group were significantly higher ( < 0.05) than those in the DAE group. (4) The serum concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein carbonyl (PC) in the HCD group were significantly higher ( 0.05) than those in the LCD group. The activity of catalase (CAT) in the LCD and DAE groups was stronger ( 0.01) than that in the HCD group. (5) The correlation analysis revealed significantly positive correlations between the plasma LPS concentration and serum concentrations of 8-OHdG ( 0.01), PC ( 0.01), and malondialdehyde (MDA, 0.05) and significantly negative correlations ( 0.01) between the plasma LPS concentration and activities of CAT and superoxide dismutase. (6) Compared with that in the HCD and DAE groups, the mRNA expression of α, β, and κ casein and acetyl CoA carboxylase in bovine mammary epithelial cells was significantly higher ( 0.05) in the LCD group, and the mRNA expression of fatty acid synthetase and stearoyl CoA desaturase in the LCD group was significantly higher ( 0.01) than that in the HCD group. (7) Compared with that in the LCD and HCD groups, the mRNA expression of Nrf2 was significantly higher ( 0.01) in the DAE group, and the mRNA expression of cystine/glutamate transporter and NAD (P) H quinone oxidoreductase 1 in the DAE group was significantly higher ( 0.05) than that in the HCD group. Overall, feeding a high-concentrate diet could increase the milk yield of dairy cows, but the milk quality, rumen homeostasis, and antioxidative capability were adversely affected. The supplementation of DAE in a high-concentrate diet enhanced antioxidative capability by activating the Nrf2 regulatory factor and improved rumen homeostasis and production performance.
Topics: Animals; Cattle; Oxidative Stress; Female; Taraxacum; Lactation; Milk; Mammary Glands, Animal; Plant Extracts; Diet; Animal Feed
PubMed: 38892271
DOI: 10.3390/ijms25116075 -
International Journal of Molecular... May 2024Pygopus (Pygo) has been identified as a specific nuclear co-activator of the canonical Wingless (Wg)/Wnt signaling pathway in . Pygo proteins consist of two conserved...
Pygopus (Pygo) has been identified as a specific nuclear co-activator of the canonical Wingless (Wg)/Wnt signaling pathway in . Pygo proteins consist of two conserved domains: an N-terminal homologous domain (NHD) and a C-terminal plant homologous domain (PHD). The PHD's ability to bind to di- and trimethylated lysine 4 of histone H3 (H3K4me2/3) appears to be independent of Wnt signaling. There is ongoing debate regarding the significance of Pygo's histone-binding capacity. Pygo orthologs have a tryptophan (W) > phenylalanine (F) substitution in their histone pocket-divider compared to vertebrates, leading to reduced histone affinity. In this research, we utilized CRISPR/Cas9 technology to introduce the Pygo-F773W point mutation in , successfully establishing a viable homozygous mutant line for the first time. Adult mutant flies displayed noticeable abnormalities in reproduction, locomotion, heart function, and lifespan. RNA-seq and cluster analysis indicated that the mutation primarily affected pathways related to immunity, metabolism, and posttranslational modification in adult flies rather than the Wnt signaling pathway. Additionally, a reduction in H3K9 acetylation levels during the embryonic stage was observed in the mutant strains. These findings support the notion that Pygo plays a wider role in chromatin remodeling, with its involvement in Wnt signaling representing only a specific aspect of its chromatin-related functions.
Topics: Animals; Drosophila Proteins; Wnt Signaling Pathway; Drosophila melanogaster; Histones; Intracellular Signaling Peptides and Proteins; Mutation; CRISPR-Cas Systems
PubMed: 38892188
DOI: 10.3390/ijms25115998 -
International Journal of Molecular... May 2024The relationship between rheumatoid arthritis (RA) and early onset atherosclerosis is well depicted, each with an important inflammatory component. Glycoprotein acetyls...
The relationship between rheumatoid arthritis (RA) and early onset atherosclerosis is well depicted, each with an important inflammatory component. Glycoprotein acetyls (GlycA), a novel biomarker of inflammation, may play a role in the manifestation of these two inflammatory conditions. The present study examined a potential mediating role of GlycA within the RA-atherosclerosis relationship to determine whether it accounts for the excess risk of cardiovascular disease over that posed by lipid risk factors. The UK Biobank dataset was acquired to establish associations among RA, atherosclerosis, GlycA, and major lipid factors: total cholesterol (TC), high- and low-density lipoprotein (HDL, LDL) cholesterol, and triglycerides (TGs). Genome-wide association study summary statistics were collected from various resources to perform genetic analyses. Causality among variables was tested using Mendelian Randomization (MR) analysis. Genes of interest were identified using colocalization analysis and gene enrichment analysis. MR results appeared to indicate that the genetic relationship between GlycA and RA and also between RA and atherosclerosis was explained by horizontal pleiotropy (-value = 0.001 and <0.001, respectively), while GlycA may causally predict atherosclerosis (-value = 0.017). Colocalization analysis revealed several functionally relevant genes shared between GlycA and all the variables assessed. Two loci were apparent in all relationships tested and included the HLA region as well as GlycA appears to mediate the RA-atherosclerosis relationship through several possible pathways. GlycA, although pleiotropically related to RA, appears to causally predict atherosclerosis. Thus, GlycA is suggested as a significant factor in the etiology of atherosclerosis development in RA.
Topics: Arthritis, Rheumatoid; Humans; Biomarkers; Genome-Wide Association Study; Cardiovascular Diseases; Atherosclerosis; Glycoproteins; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide; Genetic Predisposition to Disease
PubMed: 38892172
DOI: 10.3390/ijms25115981 -
International Journal of Molecular... May 2024The effects of the enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB), which removes the 4-sulfate group at the non-reducing end of chondroitin 4-sulfate,...
The effects of the enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB), which removes the 4-sulfate group at the non-reducing end of chondroitin 4-sulfate, on the expression of PD-L1 were determined, and the underlying mechanism of PD-L1 expression was elucidated. Initial experiments in human melanoma cells (A375) showed that PD-L1 expression increased from 357 ± 31 to 796 ± 50 pg/mg protein ( < 10) when ARSB was silenced in A375 cells. In subcutaneous B16F10 murine melanomas, PD-L1 declined from 1227 ± 189 to 583 ± 110 pg/mg protein ( = 1.67 × 10), a decline of 52%, following treatment with exogenous, bioactive recombinant ARSB. This decline occurred in association with reduced tumor growth and prolongation of survival, as previously reported. The mechanism of regulation of PD-L1 expression by ARSB is attributed to ARSB-mediated alteration in chondroitin 4-sulfation, leading to changes in free galectin-3, c-Jun nuclear localization, HDAC3 expression, and effects of acetyl-H3 on the PD-L1 promoter. These findings indicate that changes in ARSB contribute to the expression of PD-L1 in melanoma and can thereby affect the immune checkpoint response. Exogenous ARSB acted on melanoma cells and normal melanocytes through the IGF2 receptor. The decline in PD-L1 expression by exogenous ARSB may contribute to the impact of ARSB on melanoma progression.
Topics: Animals; Humans; Epigenesis, Genetic; Mice; N-Acetylgalactosamine-4-Sulfatase; B7-H1 Antigen; Histone Deacetylases; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Melanoma, Experimental; Melanoma; Galectin 3; Promoter Regions, Genetic; Blood Proteins; Galectins
PubMed: 38892038
DOI: 10.3390/ijms25115851 -
International Journal of Molecular... May 2024Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by diffuse hepatocellular steatosis due to fatty deposits in hepatocytes,...
Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by diffuse hepatocellular steatosis due to fatty deposits in hepatocytes, excluding alcohol and other known liver injury factors. However, there are no specific drugs for the clinical treatment of NAFLD. Therefore, research on the pathogenesis of NAFLD at the cellular and molecular levels is a promising approach to finding therapeutic targets and developing targeted drugs for NAFLD. Pin1 is highly expressed during adipogenesis and contributes to adipose differentiation, but its specific mechanism of action in NAFLD is unclear. In this study, we investigated the role of Pin1 in promoting the development of NAFLD and its potential mechanisms in vitro and in vivo. First, Pin1 was verified in the NAFLD model in vitro using MCD diet-fed mice by Western Blot, RT-qPCR and immunohistochemistry (IHC) assays. In the in vitro study, we used the oleic acid (OA) stimulation-induced lipid accumulation model and examined the lipid accumulation in each group of cells by oil red O staining as well as BODIPY staining. The results showed that knockdown of Pin1 inhibited lipid accumulation in hepatocytes in an in vitro lipid accumulation model and improved lipid indices and liver injury levels. Moreover, in vivo, WT and Pin1-KO mice were fed a methionine-choline deficient (MCD) diet for 4 weeks to induce the NAFLD model. The effects of Pin1 on lipid accumulation, hepatic fibrosis, and oxidative stress were evaluated by biochemical analysis, glucose and insulin tolerance tests, histological analysis, IHC, RT-qPCR and Western blot assays. The results indicate that Pin1 knockdown significantly alleviated hepatic steatosis, fibrosis and inflammation in MCD-induced NAFLD mice, improved glucose tolerance and alleviated insulin resistance in mice. Further studies showed that the AMPK/ACC1 signalling pathway might take part in the process by which Pin1 regulates NAFLD, as evidenced by the inhibition of the AMPK/ACC1 pathway. In addition, immunofluorescence (IF), coimmunoprecipitation (Co-IP) and GST pull-down experiments also showed that Pin1 interacts directly with ACC1 and inhibits ACC1 phosphorylation levels. Our study suggests that Pin1 promotes NAFLD progression by inhibiting the activation of the AMPK/ACC1 signalling pathway, and it is possible that this effect is achieved by Pin1 interacting with ACC1 and inhibiting the phosphorylation of ACC1.
Topics: Animals; NIMA-Interacting Peptidylprolyl Isomerase; Non-alcoholic Fatty Liver Disease; Mice; Male; Mice, Knockout; Hepatocytes; Humans; Lipid Metabolism; Mice, Inbred C57BL; Disease Models, Animal; Protein Binding; Acetyl-CoA Carboxylase
PubMed: 38892011
DOI: 10.3390/ijms25115822 -
International Journal of Molecular... May 2024Cellular senescence is closely related to DNA damage, proteasome inactivity, histone loss, epigenetic alterations, and tumorigenesis. The mammalian proteasome activator... (Review)
Review
Cellular senescence is closely related to DNA damage, proteasome inactivity, histone loss, epigenetic alterations, and tumorigenesis. The mammalian proteasome activator PA200 (also referred to as PSME4) or its yeast ortholog Blm10 promotes the acetylation-dependent degradation of the core histones during transcription, DNA repair, and spermatogenesis. According to recent studies, PA200 plays an important role in senescence, probably because of its role in promoting the degradation of the core histones. Loss of PA200 or Blm10 is a major cause of the decrease in proteasome activity during senescence. In this paper, recent research progress on the association of PA200 with cellular senescence is summarized, and the potential of PA200 to serve as a therapeutic target in age-related diseases is discussed.
Topics: Proteasome Endopeptidase Complex; Cellular Senescence; Humans; Animals; Proteolysis; Histones; Saccharomyces cerevisiae Proteins; Nuclear Proteins
PubMed: 38891826
DOI: 10.3390/ijms25115637 -
Cells May 2024N-acetyl-selenomethionine (NASeLM), a representative of the selenium compounds, failed to convince in clinical studies and cell cultures that it neither inhibits cancer... (Comparative Study)
Comparative Study
UNLABELLED
N-acetyl-selenomethionine (NASeLM), a representative of the selenium compounds, failed to convince in clinical studies and cell cultures that it neither inhibits cancer growth nor has a chemoprotective effect. This study aims to find out whether NASeLM shows a growth-inhibiting property compared to the carrier substance N-Acetyl-L-methionine (NALM) on two different cancer cells, namely Jurkat cells and MTC-SK cells.
METHODS
Jurkat and MTC-SK cells were cultured in the absence or presence of varying concentrations (0-500 µg/mL) of NASeLM and NALM solutions. After 0, 24, 48, and 72 h, mitochondrial activity, cancer cell membrane CP levels, cell growth, and caspase-3 activity were assessed in aliquots of Jurkat and MTC-SK cells.
RESULTS
Both substances, NASeLM and NALM, were similarly able to inhibit cell growth and mitochondrial activity of Jurkat cells in a concentration-dependent and time-dependent manner up to 70%. Only the determination of caspase activity showed that only NASeLM was able to increase this to almost 40% compared to the control as well as the same lack of NALM. However, the experiments on MTC-SK cells showed a clear difference in favor of NASeLM compared to NALM. While NASeLM was able to reduce cell growth to up to 55%, the same amount of NALM was only at around 15%, which turned out to be highly significant ( < 0.001). The same could also be measured for the reduction in MTC-SK mitochondrial activity. Time dependence could also be recognized: the longer both substances, NASeLM and NALM, were incubated, the higher the effect on cell growth and mitochondrial activity, in favour of NASeLM. Only NASeLM was able to increase caspase-3 activity in MTC-SK cells: at 250 µg/mL NASeLM, caspase-3 activity increased significantly to 28% after 24 and 48 h compared to the control (14%) or the same NALM concentration (14%). After 72 h, this could still increase to 37%. A further increase in the NASeLM concentration did not result in higher caspase-3 activity.
CONCLUSION
NASeLM could clearly increase caspase-3 activity in both cell types, Jurkat or MTC-SK cells, and thus induce cell death. NALM and NASeLM showed a reduction in cell growth and mitochondrial activity in both cell lines: While NALM and NASeLM showed almost identical measurements on Jurkat cells, NASeLM was much more effective on MTC-SK than the non-selenium-containing carrier, indicating that it has additional anti-chemoprotective effects.
Topics: Humans; Selenomethionine; Jurkat Cells; Methionine; Cell Proliferation; Mitochondria; Caspase 3; Cell Line, Tumor; Apoptosis
PubMed: 38891069
DOI: 10.3390/cells13110937 -
Nature Communications Jun 2024Despite the importance of spliceosome core components in cellular processes, their roles in cancer development, including hepatocellular carcinoma (HCC), remain poorly...
Despite the importance of spliceosome core components in cellular processes, their roles in cancer development, including hepatocellular carcinoma (HCC), remain poorly understood. In this study, we uncover a critical role for SmD2, a core component of the spliceosome machinery, in modulating DNA damage in HCC through its impact on BRCA1/FANC cassette exons and expression. Our findings reveal that SmD2 depletion sensitizes HCC cells to PARP inhibitors, expanding the potential therapeutic targets. We also demonstrate that SmD2 acetylation by p300 leads to its degradation, while HDAC2-mediated deacetylation stabilizes SmD2. Importantly, we show that the combination of Romidepsin and Olaparib exhibits significant therapeutic potential in multiple HCC models, highlighting the promise of targeting SmD2 acetylation and HDAC2 inhibition alongside PARP inhibitors for HCC treatment.
Topics: Humans; Carcinoma, Hepatocellular; Liver Neoplasms; Acetylation; Poly(ADP-ribose) Polymerase Inhibitors; Spliceosomes; Cell Line, Tumor; Phthalazines; Exons; Piperazines; Animals; BRCA1 Protein; Depsipeptides; Mice; DNA Damage; Gene Expression Regulation, Neoplastic
PubMed: 38890388
DOI: 10.1038/s41467-024-49573-7