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1.
PLoS Pathog ; 17(3): e1009320, 2021 03.
Article in English | MEDLINE | ID: mdl-33662035

ABSTRACT

Humans are frequently exposed to bacterial genotoxins of the gut microbiota, such as colibactin and cytolethal distending toxin (CDT). In the present study, whole genome microarray-based identification of differentially expressed genes was performed in vitro on HT29 intestinal cells while following the ectopic expression of the active CdtB subunit of Helicobacter hepaticus CDT. Microarray data showed a CdtB-dependent upregulation of transcripts involved in positive regulation of autophagy concomitant with the downregulation of transcripts involved in negative regulation of autophagy. CdtB promotes the activation of autophagy in intestinal and hepatic cell lines. Experiments with cells lacking autophagy related genes, ATG5 and ATG7 infected with CDT- and colibactin-producing bacteria revealed that autophagy protects cells against the genotoxin-induced apoptotic cell death. Autophagy induction could also be associated with nucleoplasmic reticulum (NR) formation following DNA damage induced by these bacterial genotoxins. In addition, both genotoxins promote the accumulation of the autophagic receptor P62/SQSTM1 aggregates, which colocalized with foci concentrating the RNA binding protein UNR/CSDE1. Some of these aggregates were deeply invaginated in NR in distended nuclei together or in the vicinity of UNR-rich foci. Interestingly, micronuclei-like structures and some vesicles containing chromatin and γH2AX foci were found surrounded with P62/SQSTM1 and/or the autophagosome marker LC3. This study suggests that autophagy and P62/SQSTM1 regulate the abundance of micronuclei-like structures and are involved in cell survival following the DNA damage induced by CDT and colibactin. Similar effects were observed in response to DNA damaging chemotherapeutic agents, offering new insights into the context of resistance of cancer cells to therapies inducing DNA damage.


Subject(s)
Autophagy/drug effects , Bacterial Toxins/pharmacology , DNA-Binding Proteins/metabolism , RNA-Binding Proteins/drug effects , Sequestosome-1 Protein/metabolism , Autophagy/physiology , Cell Nucleus/metabolism , Endoplasmic Reticulum Stress/physiology , Helicobacter hepaticus/metabolism , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Mutagens/metabolism , RNA-Binding Proteins/metabolism , Sequestosome-1 Protein/genetics
2.
Bioconjug Chem ; 34(1): 238-247, 2023 01 18.
Article in English | MEDLINE | ID: mdl-36516871

ABSTRACT

As a counterpart to antibody-drug conjugates (ADCs), aptamer-drug conjugates (ApDCs) have been considered a promising strategy for targeted therapy due to the various benefits of aptamers. However, an aptamer merely serves as a targeting ligand in ApDCs, whereas the antibody enables the unexpected therapeutic efficacy of ADCs through antibody-dependent cellular cytotoxicity (ADCC). In this study, we developed a tumor-specific aptamer with an effector function and used it to confirm the feasibility of more potent ApDCs. First, we designed a nucleolin (NCL)-binding G-quadruplex (GQ) library based on the ability of NCL to bind to telomeric sequences. We then identified a bifunctional GQ aptamer (BGA) inhibiting the catalytic activity of topoisomerase 1 (TOP1) by forming an irreversible cleavage complex. Our BGA specifically targeted NCL-positive MCF-7 cells, exhibiting antiproliferative activity, and this suggested that tumor-specific therapeutic aptamers can be developed by using a biased library to screen aptamer candidates for functional targets. Finally, we utilized DM1, which has a synergistic interaction with TOP1 inhibitors, as a conjugated drug. BGA-DM1 exerted an anticancer effect 20-fold stronger than free DM1 and even 10-fold stronger than AS1411 (NCL aptamer)-DM1, highlighting our approach to develop synergistic ApDCs. Therefore, we anticipate that our library might be utilized for the identification of aptamers with effector functions. Furthermore, by employing such aptamers and appropriate drugs, synergistic ApDCs can be developed for targeted cancer therapy in a manner distinct from how ADCs exhibit additional therapeutic efficacy.


Subject(s)
Aptamers, Nucleotide , DNA Topoisomerases, Type I , RNA-Binding Proteins , Humans , Aptamers, Nucleotide/pharmacology , Aptamers, Nucleotide/metabolism , MCF-7 Cells , Phosphoproteins/metabolism , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/metabolism , DNA Topoisomerases, Type I/drug effects , DNA Topoisomerases, Type I/metabolism , Drug Synergism , Nucleolin
3.
Anticancer Drugs ; 33(1): e134-e144, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34387591

ABSTRACT

Circular RNAs (circRNAs) are important regulators that drive or inhibit cancer initiation and development. Here, we identified the expression and function of a circRNA, circ_KIAA1199, in colorectal cancer (CRC). The expression levels of circ_KIAA1199, microRNA-34c-5p (miR-34c-5p) and Musashi RNA-binding protein 1 (MSI1) mRNA were detected by quantitative real-time PCR. Cell proliferative capacity was assessed by colony formation assay, EdU assay and MTT assay. Cell apoptosis was determined by flow cytometry assay. Cell migration and cell invasion were investigated by transwell assay. The expression of MSI1 protein and proliferation, migration-related markers was detected by western blot. The relationship between miR-34c-5p and circ_KIAA1199 or MSI1 was verified by dual-luciferase reporter assay. Animal models were constructed to ascertain the role of circ_KIAA1199 in vivo. The expression of circ_KIAA1199 was elevated in CRC. Circ_KIAA1199 downregulation suppressed CRC cell proliferation, survival, migration and invasion. MiR-34c-5p was a target of circ_KIAA1199. The effects of circ_KIAA1199 downregulation were reversed by miR-34c-5p deficiency. In addition, MSI1 was a target of circ_KIAA1199, and the inhibitory effects of miR-34c-5p restoration on CRC cell proliferation, survival, migration and invasion were reversed by MSI1 overexpression. Circ_KIAA1199 positively regulated MSI1 expression by targeting miR-34c-5p. Moreover, circ_KIAA1199 knockdown blocked tumor growth in animal models. Circ_KIAA1199 functioned as an oncogene to drive the malignant development of CRC by activating MSI1 via competitively targeting miR-34c-5p.


Subject(s)
Colorectal Neoplasms/pathology , MicroRNAs/drug effects , Nerve Tissue Proteins/drug effects , RNA, Circular/pharmacology , RNA-Binding Proteins/drug effects , Animals , Apoptosis/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Down-Regulation/drug effects , Female , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Tumor Burden , Xenograft Model Antitumor Assays
4.
Nucleic Acids Res ; 48(15): 8576-8590, 2020 09 04.
Article in English | MEDLINE | ID: mdl-32761127

ABSTRACT

The IGF2 mRNA-binding protein 1 (IGF2BP1) is a non-catalytic post-transcriptional enhancer of tumor growth upregulated and associated with adverse prognosis in solid cancers. However, conserved effector pathway(s) and the feasibility of targeting IGF2BP1 in cancer remained elusive. We reveal that IGF2BP1 is a post-transcriptional enhancer of the E2F-driven hallmark in solid cancers. IGF2BP1 promotes G1/S cell cycle transition by stabilizing mRNAs encoding positive regulators of this checkpoint like E2F1. This IGF2BP1-driven shortening of the G1 cell cycle phase relies on 3'UTR-, miRNA- and m6A-dependent regulation and suggests enhancement of cell cycle progression by m6A-modifications across cancers. In addition to E2F transcription factors, IGF2BP1 also stabilizes E2F-driven transcripts directly indicating post-transcriptional 'super'-enhancer role of the protein in E2F-driven gene expression in cancer. The small molecule BTYNB disrupts this enhancer function by impairing IGF2BP1-RNA association. Consistently, BTYNB interferes with E2F-driven gene expression and tumor growth in experimental mouse tumor models.


Subject(s)
E2F Transcription Factors/genetics , Neoplasms/genetics , RNA-Binding Proteins/genetics , 3' Untranslated Regions/genetics , Animals , Cell Line, Tumor , E2F1 Transcription Factor/genetics , Gene Expression Regulation, Neoplastic/genetics , Humans , Mice , Neoplasms/pathology , RNA-Binding Proteins/drug effects , Small Molecule Libraries/pharmacology
5.
Mol Cancer ; 20(1): 78, 2021 05 26.
Article in English | MEDLINE | ID: mdl-34039363

ABSTRACT

BACKGROUND: Distant metastasis is the major cause of death in patients with colorectal cancer (CRC). Previously, we identified KITENIN as a metastasis-enhancing gene and suggested that the oncogenic KITENIN complex is involved in metastatic dissemination of KITENIN-overexpressing CRC cells. Here, we attempted to find substances targeting the KITENIN complex and test their ability to suppress distant metastasis of CRC. METHODS: We screened a small-molecule compound library to find candidate substances suppressing the KITENIN complex in CRC cells. We selected a candidate compound and examined its effects on the KITENIN complex and distant metastasis through in vitro assays, a molecular docking model, and in vivo tumor models. RESULTS: Among several compounds, we identified DKC1125 (Disintegrator of KITENIN Complex #1125) as the best candidate. DKC1125 specifically suppressed KITENIN gain of function. After binding KH-type splicing regulatory protein (KSRP), DKC1125 degraded KITENIN and Dvl2 by recruiting RACK1 and miRNA-124, leading to the disintegration of the functional KITENIN-KSRP-RACK1-Dvl2 complex. A computer docking model suggested that DKC1125 specifically interacted with the binding pocket of the fourth KH-domain of KSRP. KITENIN-overexpressing CRC cells deregulated certain microRNAs and were resistant to 5-fluorouracil, oxaliplatin, and cetuximab. DKC1125 restored sensitivity to these drugs by normalizing expression of the deregulated microRNAs, including miRNA-124. DKC1125 effectively suppressed colorectal liver metastasis in a mouse model. Interestingly, the combination of DKC1125 with 5-fluorouracil suppressed metastasis more effectively than either drug alone. CONCLUSION: DKC1125 targets the KITENIN complex and could therefore be used as a novel therapeutic to suppress liver metastasis in CRC expressing high levels of KITENIN.


Subject(s)
Antineoplastic Agents/pharmacology , Carrier Proteins/drug effects , Colorectal Neoplasms/pathology , Membrane Proteins/drug effects , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/metabolism , Trans-Activators/drug effects , Trans-Activators/metabolism , Animals , Antineoplastic Agents/chemistry , Drug Discovery , Humans , Mice , Molecular Docking Simulation , Neoplasm Metastasis/pathology , RNA-Binding Proteins/antagonists & inhibitors , Trans-Activators/antagonists & inhibitors
6.
Pharm Res ; 37(7): 145, 2020 Jul 14.
Article in English | MEDLINE | ID: mdl-32666304

ABSTRACT

PURPOSE: To construct aptamer AS1411-functionalized targeted lipid nanobubbles that could simultaneously target abnormally highly expressed nucleolin (NCL) on tumor tissue and neovasculature. Additionally, the study of their contrast-enhanced ultrasound molecular imaging capabilities in vitro and in vivo to explore new methods and approaches for the early and accurate diagnosis of triple-negative breast cancer (TNBC). METHODS: First, the targeted lipid-nucleic acid molecules were constructed by an amide reaction. Then, the targeted lipid nanobubbles (AS1411-NBs) and nontargeted lipid nanobubbles (NBs) were prepared by membrane hydration, mechanical vibration and centrifugal floatation. The physicochemical characteristics and contrast-enhanced ultrasound imaging capabilities of AS1411-NBs and NBs were compared and analyzed in vitro and in vivo. RESULTS: There were no significant differences between the AS1411-NBs and NBs in their concentration, average particle size or ultrasound imaging capabilities in vitro (P > 0.05). However, AS1411-NBs could simultaneously target NCL in tumor tissue and neovasculature to effectively prolong the duration of contrast-enhanced ultrasound imaging compared to NBs in vivo. The area under the time-intensity curve was significantly different between AS1411-NBs and NBs (P < 0.001), and the drug loading capacity of the AS1411-NBs was also significantly higher than that of the NBs (P < 0.05). CONCLUSIONS: Aptamer AS1411-functionalized targeted lipid nanobubbles could significantly prolong the duration of contrast-enhanced ultrasound imaging to achieve dual-targeted ultrasound molecular imaging of tumor tissue and neovasculature. AS1411-NBs also have higher drug loading and targeted drug delivery capabilities compared with NBs, which can provide new methods and approaches for the early accurate diagnosis and effective treatment of TNBC.


Subject(s)
Breast Neoplasms/diagnostic imaging , Contrast Media/chemistry , Lipids/chemistry , Microbubbles , Phosphoproteins/drug effects , RNA-Binding Proteins/drug effects , Triple Negative Breast Neoplasms/diagnostic imaging , Animals , Cell Line, Tumor , Drug Delivery Systems , Female , Humans , Mice , Mice, Inbred BALB C , Molecular Imaging/methods , Neovascularization, Pathologic/diagnostic imaging , Particle Size , Ultrasonography , Xenograft Model Antitumor Assays , Nucleolin
7.
Methods ; 167: 124-133, 2019 09 01.
Article in English | MEDLINE | ID: mdl-31185274

ABSTRACT

Protein synthesis is critical to cell survival and translation regulation is essential to post-transcriptional gene expression regulation. Disorders of this process, particularly through RNA-binding proteins, is associated with the development and progression of a number of diseases, including cancers. However, the molecular mechanisms underlying the initiation of protein synthesis are intricate, making it difficult to find a drug that interferes with this process. Chemical probes are useful in elucidating the structures of RNA-protein complex and molecular mechanism of biological events. Moreover, some of these chemical probes show certain therapeutic benefits and can be further developed as leading compounds. Here, we will briefly review the general process and mechanism of protein synthesis, and emphasis on chemical probes in examples of probing the RNA structural changes and RNA-protein interactions. Moreover, the therapeutic potential of these probes is also discussed to give a comprehensive understanding.


Subject(s)
Molecular Biology/methods , Protein Biosynthesis/drug effects , RNA/isolation & purification , Small Molecule Libraries/chemistry , Gene Expression Regulation/drug effects , Humans , Nucleic Acid Conformation/drug effects , Protein Biosynthesis/genetics , RNA/chemistry , RNA/drug effects , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/genetics , Small Molecule Libraries/pharmacology
8.
Am J Physiol Lung Cell Mol Physiol ; 316(3): L558-L566, 2019 03 01.
Article in English | MEDLINE | ID: mdl-30628489

ABSTRACT

Proapoptotic and monocyte chemotactic endothelial monocyte-activating protein 2 (EMAPII) is released extracellularly during cigarette smoke (CS) exposure. We have previously demonstrated that, when administered intratracheally during chronic CS exposures, neutralizing rat antibodies to EMAPII inhibited endothelial cell apoptosis and lung inflammation and reduced airspace enlargement in mice (DBA/2J strain). Here we report further preclinical evaluation of EMAPII targeting using rat anti-EMAPII antibodies via either nebulization or subcutaneous injection. Both treatment modalities efficiently ameliorated emphysema-like disease in two different strains of CS-exposed mice, DBA/2J and C57BL/6. Of relevance for clinical applicability, this treatment showed therapeutic and even curative potential when administered either during or following CS-induced emphysema development, respectively. In addition, a fully humanized neutralizing anti-EMAPII antibody administered subcutaneously to mice during CS exposure retained anti-apoptotic and anti-inflammatory effects similar to that of the parent rat antibody. Furthermore, humanized anti-EMAPII antibody treatment attenuated CS-induced autophagy and restored mammalian target of rapamycin signaling in the lungs of mice, despite ongoing CS exposure. Together, our results demonstrate that EMAPII secretion is involved in CS-induced lung inflammation and cell injury, including apoptosis and autophagy, and that a humanized EMAPII neutralizing antibody may have therapeutic potential in emphysema.


Subject(s)
Antibodies, Neutralizing/pharmacology , Lung Injury/drug therapy , Pulmonary Disease, Chronic Obstructive/drug therapy , Pulmonary Emphysema/drug therapy , Smoking/adverse effects , Animals , Autophagy/drug effects , Cytokines/drug effects , Lung Injury/metabolism , Mice, Inbred C57BL , Mice, Inbred DBA , Monocytes/drug effects , Monocytes/metabolism , Neoplasm Proteins/drug effects , Pneumonia/metabolism , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Emphysema/metabolism , RNA-Binding Proteins/drug effects
9.
Mol Biol Rep ; 46(1): 587-596, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30519811

ABSTRACT

The hormone insulin plays a central role in the metabolism of carbohydrates, lipids, and proteins. In relation to protein metabolism, insulin stimulates amino acid uptake and activates protein synthesis in responsive cells by modulation of signal transduction pathways, such as associated to Akt/PkB, mTOR, S6Ks, 4E-BP1, and several translation initiation/elongation factors. In this context, there is no information on direct cellular treatment with insulin and effects on eukaryotic translation initiation factor 5A (eIF5A) regulation. The eIF5A protein contains an exclusive amino acid residue denominated hypusine, which is essential for its activity and synthesized by posttranslational modification of a specific lysine residue using spermidine as substrate. The eIF5A protein is involved in cellular proliferation and differentiation processes, as observed for satellite cells derived from rat muscles, revealing that eIF5A has an important role in muscle regeneration. The aim of this study was to determine whether eIF5A expression and hypusination are influenced by direct treatment of insulin on L6 myoblast cells. We observed that insulin increased the content of eIF5A transcripts. This effect occurred in cells treated or depleted of fetal bovine serum, revealing a positive insulin effect independent of other serum components. In addition, it was observed that hypusination follows the maintenance of eIF5A protein content in the serum depleted cells and treated with insulin. These results demonstrate that eIF5A is modulated by insulin, contributing the protein synthesis machinery control, as observed by puromycin incorporation in nascent proteins.


Subject(s)
Insulin/metabolism , Lysine/analogs & derivatives , Peptide Initiation Factors/drug effects , RNA-Binding Proteins/drug effects , Animals , Cell Differentiation/drug effects , Cell Line , Cell Proliferation/drug effects , Insulin/pharmacology , Lysine/drug effects , Myoblasts/drug effects , Peptide Initiation Factors/genetics , Protein Biosynthesis/drug effects , Protein Processing, Post-Translational , RNA-Binding Proteins/genetics , Rats , Signal Transduction/drug effects , Eukaryotic Translation Initiation Factor 5A
10.
Int J Neuropsychopharmacol ; 21(8): 758-763, 2018 08 01.
Article in English | MEDLINE | ID: mdl-29762664

ABSTRACT

BACKGROUND: Methamphetamine use is associated with a variety of negative health outcomes, including psychosis. The frontal cortex serotonin receptors are thought to contribute to psychosis-like behaviors. This study investigated changes in serotonergic markers in the frontal cortex following methamphetamine self-administration and hallucinogenic drug-induced behavior. METHODS: Consistent with previously published studies, freely cycling male and female rats were allowed to self-administer methamphetamine (males: 0.12 mg/infusion; females: 0.09 mg/infusion) or saline (10 µL) for 7 days. On the day following self-administration or following 10 days of extinction training, animals were given the serotonin 2A/2C agonist, 1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (2 mg/kg, i.p.), and head twitches were analyzed. Autoradiography was also used to assess serotonin receptors and transporters in the frontal cortex following self-administration. RESULTS: Methamphetamine self-administration led to an increase in DOI-induced head-twitch behavior compared to saline only on the day following self-administration. Increases in serotonin receptors in the orbitofrontal cortex and decreases in serotonin transporters in the orbitofrontal cortex and infralimbic cortex were observed following methamphetamine self-administration as assessed by autoradiography. CONCLUSIONS: Methamphetamine self-administration was associated with serotonergic alterations in the frontal cortex, which may underlie behavioral changes related to methamphetamine-associated psychosis.


Subject(s)
Amphetamine-Related Disorders/complications , Behavior, Animal/drug effects , Frontal Lobe/drug effects , Hallucinogens/toxicity , Methamphetamine/toxicity , Psychoses, Substance-Induced/etiology , Serotonin/metabolism , Amphetamine-Related Disorders/metabolism , Amphetamine-Related Disorders/physiopathology , Animals , Female , Frontal Lobe/metabolism , Hallucinogens/administration & dosage , Male , Methamphetamine/administration & dosage , Psychoses, Substance-Induced/metabolism , Psychoses, Substance-Induced/psychology , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/metabolism , Rats, Sprague-Dawley , Receptors, Serotonin, 5-HT2/drug effects , Receptors, Serotonin, 5-HT2/metabolism , Self Administration , Time Factors
11.
Mem Inst Oswaldo Cruz ; 113(9): e180162, 2018 Jul 26.
Article in English | MEDLINE | ID: mdl-30066751

ABSTRACT

Eukaryotic initiation factor 5A (eIF5A) is a conserved protein with an essential role in translation elongation. Using one and two-dimensional western blotting, we showed that the eIF5A protein level was 2-fold lower in benznidazole (BZ)-resistant (BZR and 17LER) Trypanosoma cruzi populations than in their respective susceptible counterparts (BZS and 17WTS). To confirm the role of eIF5A in BZ resistance, we transfected BZS and 17WTS with the wild-type eIF5A or mutant eIF5A-S2A (in which serine 2 was replaced by alanine). Upon overexpressing eIF5A, both susceptible lines became approximately 3- and 5-fold more sensitive to BZ. In contrast, the eIF5A-S2A mutant did not alter its susceptibility to BZ. These data suggest that BZ resistance might arise from either decreasing the translation of proteins that require eIF5A, or as a consequence of differential levels of precursors for the hypusination reactions (e.g., spermidine and trypanothione), both of which alter BZ's effects in the parasite.


Subject(s)
Drug Resistance/genetics , Nitroimidazoles/pharmacology , Peptide Initiation Factors/metabolism , RNA-Binding Proteins/metabolism , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/enzymology , Gene Expression , Humans , Peptide Initiation Factors/analysis , Peptide Initiation Factors/drug effects , RNA-Binding Proteins/analysis , RNA-Binding Proteins/drug effects , Trypanosoma cruzi/genetics , Eukaryotic Translation Initiation Factor 5A
12.
J Am Soc Nephrol ; 28(3): 811-822, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27612998

ABSTRACT

The eukaryotic initiation factor 5A (eIF5A), which is highly conserved throughout evolution, has the unique characteristic of post-translational activation through hypusination. This modification is catalyzed by two enzymatic steps involving deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). Notably, eIF5A may be involved in regulating the lifespan of Drosophila during long-term hypoxia. Therefore, we investigated the possibility of a link between eIF5A hypusination and cellular resistance to hypoxia/anoxia. Pharmacologic targeting of DHPS by N1-guanyl-1,7-diaminoheptane (GC7) or RNA interference-mediated inhibition of DHPS or DOHH induced tolerance to anoxia in immortalized mouse renal proximal cells. Furthermore, GC7 treatment of cells reversibly induced a metabolic shift toward glycolysis as well as mitochondrial remodeling and led to downregulated expression and activity of respiratory chain complexes, features characteristic of mitochondrial silencing. GC7 treatment also attenuated anoxia-induced generation of reactive oxygen species in these cells and in normoxic conditions, decreased the mitochondrial oxygen consumption rate of cultured cells and mice. In rats, intraperitoneal injection of GC7 substantially reduced renal levels of hypusinated eIF5A and protected against ischemia-reperfusion-induced renal injury. Finally, in the preclinical pig kidney transplant model, intravenous injection of GC7 before kidney removal significantly improved graft function recovery and late graft function and reduced interstitial fibrosis after transplant. This unconventional signaling pathway offers an innovative therapeutic target for treating hypoxic-ischemic human diseases and organ transplantation.


Subject(s)
Cell Death/drug effects , Kidney Transplantation , Lysine/analogs & derivatives , Mitochondria/drug effects , Mitochondria/physiology , Peptide Initiation Factors/drug effects , RNA-Binding Proteins/drug effects , Animals , Cell Hypoxia/drug effects , Cells, Cultured , Female , Lysine/pharmacology , Male , Mice , Mice, Inbred C57BL , Mixed Function Oxygenases , Rats , Rats, Wistar , Swine , Treatment Outcome , Eukaryotic Translation Initiation Factor 5A
13.
Am J Physiol Endocrinol Metab ; 311(5): E836-E849, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27677502

ABSTRACT

Alcohol ingestion decreases postexercise rates of muscle protein synthesis, but the mechanism(s) (e.g., increased protein breakdown) underlying this observation is unknown. Autophagy is an intracellular "recycling" system required for homeostatic substrate and organelle turnover; its dysregulation may provoke apoptosis and lead to muscle atrophy. We investigated the acute effects of alcohol ingestion on autophagic cell signaling responses to a bout of concurrent (combined resistance- and endurance-based) exercise. In a randomized crossover design, eight physically active males completed three experimental trials of concurrent exercise with either postexercise ingestion of alcohol and carbohydrate (12 ± 2 standard drinks; ALC-CHO), energy-matched alcohol and protein (ALC-PRO), or protein (PRO) only. Muscle biopsies were taken at rest and 2 and 8 h postexercise. Select autophagy-related gene (Atg) proteins decreased compared with rest with ALC-CHO (P < 0.05) but not ALC-PRO. There were parallel increases (P < 0.05) in p62 and PINK1 commensurate with a reduction in BNIP3 content, indicating a diminished capacity for mitochondria-specific autophagy (mitophagy) when alcohol and carbohydrate were coingested. DNA fragmentation increased in both alcohol conditions (P < 0.05); however, nuclear AIF accumulation preceded this apoptotic response with ALC-CHO only (P < 0.05). In contrast, increases in the nuclear content of p53, TFEB, and PGC-1α in ALC-PRO were accompanied by markers of mitochondrial biogenesis at the transcriptional (Tfam, SCO2, and NRF-1) and translational (COX-IV, ATPAF1, and VDAC1) level (P < 0.05). We conclude that alcohol ingestion following exercise triggers apoptosis, whereas the anabolic properties of protein coingestion may stimulate mitochondrial biogenesis to protect cellular homeostasis.


Subject(s)
Apoptosis/drug effects , Autophagy/drug effects , Central Nervous System Depressants/pharmacology , Dietary Carbohydrates/pharmacology , Dietary Proteins/pharmacology , Ethanol/pharmacology , Exercise/physiology , Muscle Fibers, Skeletal/drug effects , Adolescent , Adult , Alcohol Drinking , Apoptosis/physiology , Autophagy/physiology , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/drug effects , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism , Carrier Proteins/drug effects , Carrier Proteins/metabolism , Cross-Over Studies , DNA Fragmentation/drug effects , DNA-Binding Proteins/drug effects , DNA-Binding Proteins/metabolism , Electron Transport Complex IV/drug effects , Electron Transport Complex IV/metabolism , Healthy Volunteers , Humans , Male , Membrane Proteins/drug effects , Membrane Proteins/metabolism , Mitochondrial Proteins/drug effects , Mitochondrial Proteins/metabolism , Mitochondrial Proton-Translocating ATPases/drug effects , Mitochondrial Proton-Translocating ATPases/metabolism , Mitophagy/drug effects , Mitophagy/physiology , Molecular Chaperones/drug effects , Molecular Chaperones/metabolism , Muscle Fibers, Skeletal/physiology , Nuclear Respiratory Factor 1/drug effects , Nuclear Respiratory Factor 1/metabolism , Organelle Biogenesis , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/drug effects , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Protein Kinases/drug effects , Protein Kinases/metabolism , Proto-Oncogene Proteins/drug effects , Proto-Oncogene Proteins/metabolism , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/metabolism , Signal Transduction/drug effects , Transcription Factors/drug effects , Transcription Factors/metabolism , Tumor Suppressor Protein p53/drug effects , Tumor Suppressor Protein p53/metabolism , Voltage-Dependent Anion Channel 1/drug effects , Voltage-Dependent Anion Channel 1/metabolism , Young Adult
14.
J Neurochem ; 139(2): 181-186, 2016 10.
Article in English | MEDLINE | ID: mdl-27454326

ABSTRACT

The mouse monoclonal antibody marketed as anti-adenomatous polyposis coli clone CC1, often referred to as CC1, is the antibody most commonly used to specifically label mature oligodendrocytes without labeling myelin. Previous studies have shown that despite being raised against adenomatous polyposis coli, this antibody binds another unknown antigen. We show that the CC1 antibody binds Quaking 7, an RNA-binding protein that is highly up-regulated in myelinating oligodendrocytes in the central nervous system. The monoclonal antibody anti-adenomatous polyposis coli (APC) clone CC1, is the antibody most commonly used to specifically label the cell bodies of mature oligodendrocytes. Despite being raised against APC, previous studies showed this antibody binds another unknown antigen. We show that the CC1 antibody binds Quaking (QKI) 7, an RNA-binding protein which is highly up-regulated in myelinating oligodendrocytes.


Subject(s)
Antibodies, Monoclonal/pharmacology , Oligodendroglia/drug effects , RNA-Binding Proteins/metabolism , Amino Acid Sequence , Animals , Antibody Specificity , Cells, Cultured , Central Nervous System/drug effects , Cerebral Cortex/cytology , Cerebral Cortex/drug effects , HEK293 Cells , Humans , Mice , Mice, Inbred C57BL , Myelin Sheath/metabolism , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/drug effects , Rats , Rats, Sprague-Dawley , Transfection
15.
Eur J Gynaecol Oncol ; 37(2): 238-43, 2016.
Article in English | MEDLINE | ID: mdl-27172752

ABSTRACT

OBJECTIVES: To investigate the effect and the mechanism of anti-tumor agent hydroxycamptothecin (HCPT) on HeLa cells in cervical cancer. MATERIALS AND METHODS: Autophagy and apoptosis were detected by western blotting and the transfection of GFP-LC3 shRNA as well as Hoechst staining. RESULTS: The authors found that the expression of the regulators of Beclin-1, p62, and microtubule-associated protein 1 light chain 3 (LC3) upregulated and then triggered the occurrence of cell autophagy. On the other hand, HCPT could induce to the formation of autophagy and resulted in cell apoptosis after autophagy. CONCLUSION: HCPT can alter cell autophagy and then trigger cell apoptosis to achieve antitumor effects.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Camptothecin/analogs & derivatives , Uterine Cervical Neoplasms , Apoptosis Regulatory Proteins/drug effects , Apoptosis Regulatory Proteins/metabolism , Beclin-1 , Blotting, Western , Camptothecin/pharmacology , Caspase 3/drug effects , Caspase 3/metabolism , Cell Survival/drug effects , Drug Screening Assays, Antitumor , Female , HeLa Cells , Humans , Membrane Proteins/drug effects , Membrane Proteins/metabolism , Microtubule-Associated Proteins/drug effects , Microtubule-Associated Proteins/metabolism , Proto-Oncogene Proteins c-bcl-2/drug effects , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/metabolism , bcl-2-Associated X Protein/drug effects , bcl-2-Associated X Protein/metabolism
16.
Hepatology ; 60(4): 1241-50, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24824848

ABSTRACT

UNLABELLED: The far upstream element binding protein (FBP) and the FBP-interacting repressor (FIR) represent molecular tools for transcriptional fine tuning of target genes. Strong overexpression of FBP in human hepatocellular carcinoma (HCC) supports tumor growth and correlates with poor patient prognosis. However, the role of the transcriptional repressor FIR in hepatocarcinogenesis remains poorly delineated. We show that overexpression of FIR correlates with tumor dedifferentiation and tumor cell proliferation in about 60% of primary HCCs. Elevated FIR levels are associated with genomic gains of the FIR gene locus at chromosome 8q24.3 in human HCC specimens. In vitro, nuclear enrichment of FIR supports HCC cell proliferation and migration. Expression profiling of HCC cells after small interfering RNA (siRNA)-mediated silencing of FIR identified the transcription factor DP-1 (TFDP1) as a transcriptional target of FIR. Surprisingly, FIR stimulates the expression of FBP in a TFDP1/E2F1-dependent manner. FIR splice variants lacking or containing exon 2 and/or exon 5 are expressed in the majority of HCCs but not in normal hepatocytes. Specific inhibition of FIR isoforms with and without exon 2 revealed that both groups of FIR splice variants facilitate tumor-supporting effects. This finding was confirmed in xenograft transplantation experiments with lentiviral-infected short hairpin RNA (shRNA) targeting all FIR variants as well as FIR with and without exon 2. CONCLUSION: High-level nuclear FIR does not facilitate repressor properties but supports tumor growth in HCC cells. Thus, the pharmacological inhibition of FIR might represent a promising therapeutic strategy for HCC patients with elevated FIR expression.


Subject(s)
Carcinoma, Hepatocellular/physiopathology , Cell Differentiation/physiology , Cell Movement/physiology , Cell Proliferation/physiology , DNA Helicases/physiology , DNA-Binding Proteins/physiology , Liver Neoplasms/physiopathology , RNA-Binding Proteins/physiology , Repressor Proteins/physiology , Animals , Carcinoma, Hepatocellular/pathology , DNA Helicases/drug effects , DNA Helicases/genetics , DNA-Binding Proteins/drug effects , DNA-Binding Proteins/genetics , Exons/genetics , Humans , In Vitro Techniques , Liver Neoplasms/pathology , Mice, SCID , Mice, Transgenic , Protein Isoforms/genetics , RNA Splicing Factors , RNA, Small Interfering/pharmacology , RNA-Binding Proteins/drug effects , RNA-Binding Proteins/genetics , Repressor Proteins/drug effects , Repressor Proteins/genetics , Transcription Factor DP1/physiology , Transplantation, Heterologous
17.
J Pathol ; 233(4): 415-24, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24974828

ABSTRACT

Translocations involving ETS-transcription factors, most commonly leading to the EWSR1-FLI1 fusion protein, are the hallmark of Ewing sarcoma. Despite knowledge of this driving molecular event, an effective therapeutic strategy is lacking. To test potential treatment regimes, we established a novel Ewing sarcoma zebrafish engraftment model allowing time-effective, dynamic quantification of Ewing sarcoma progression and tumour burden in vivo, applicable for screening of single and combined compounds. In Ewing sarcoma the tumour-suppressor gene TP53 is commonly found to be wild-type, thus providing an attractive target for treatment. Here, we study TP53 wild-type (EW7, CADO-ES1 and TC32) and TP53-deleted (SK-N-MC) Ewing sarcoma cell lines to investigate the potentiating effect of p53 reactivation by Nutlin-3 on treatment with YK-4-279 to block transcriptional activity of EWSR1-FLI1 protein. Blocking EWSR1-FLI1 transcriptional activity reduced Ewing sarcoma tumour cell burden irrespective of TP53 status. We show that simultaneous YK-4-279 treatment with Nutlin-3 to stabilize p53 resulted in an additive inhibition of TP53 wild-type Ewing sarcoma cell burden, whilst not affecting TP53-deleted Ewing sarcoma cells. Improved inhibition of proliferation and migration by combinatorial treatment was confirmed in vivo by zebrafish engraftments. Mechanistically, both compounds together additively induced apoptosis of tumour cells in vivo by engaging distinct pathways. We propose reactivation of the p53 pathway in combination with complementary targeted therapy by EWSR1-FLI1 transcriptional activity disruption as a valuable strategy against p53 wild-type Ewing sarcoma.


Subject(s)
Bone Neoplasms/prevention & control , RNA-Binding Proteins/genetics , Sarcoma, Ewing/prevention & control , Transcription, Genetic/physiology , Tumor Suppressor Protein p53/physiology , Zebrafish Proteins/genetics , Animals , Antineoplastic Agents/pharmacology , Bone Neoplasms/genetics , Bone Neoplasms/physiopathology , Cell Line, Tumor , Cells, Cultured , Disease Models, Animal , Drug Synergism , Heterografts , Humans , Imidazoles/pharmacology , Indoles/pharmacology , Piperazines/pharmacology , RNA-Binding Protein EWS , RNA-Binding Proteins/drug effects , Sarcoma, Ewing/genetics , Sarcoma, Ewing/physiopathology , Signal Transduction/drug effects , Transcription, Genetic/drug effects , Transcription, Genetic/genetics , Tumor Suppressor Protein p53/drug effects , Tumor Suppressor Protein p53/genetics , Zebrafish , Zebrafish Proteins/drug effects
19.
Biosci Biotechnol Biochem ; 78(11): 1850-5, 2014.
Article in English | MEDLINE | ID: mdl-25351333

ABSTRACT

Floral transition is regulated by environmental and endogenous signals. Previously, we identified VASCULAR PLANT ONE-ZINC FINGER1 (VOZ1) and VOZ2 as phytochrome B-interacting factors. VOZ1 and VOZ2 redundantly promote flowering and have pivotal roles in the downregulation of FLOWERING LOCUS C (FLC), a central repressor of flowering in Arabidopsis. Here, we showed that the late-flowering phenotypes of the voz1 voz2 mutant were suppressed by vernalization in the Columbia and FRIGIDA (FRI)-containing accessions, which indicates that the late-flowering phenotype of voz1 voz2 mutants was caused by upregulation of FLC. We also showed that the other FLC clade members, MADS AFFECTING FLOWERING (MAF) genes, were also a downstream target of VOZ1 and VOZ2 as their expression levels were also increased in the voz1 voz2 mutant. Our results suggest that the FLC clade genes integrate signals from VOZ1/VOZ2 and vernalization to regulate flowering.


Subject(s)
Arabidopsis Proteins/drug effects , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Arabidopsis/growth & development , Arabidopsis/genetics , Flowers/genetics , Gene Expression Regulation, Plant , MADS Domain Proteins/genetics , MADS Domain Proteins/metabolism , RNA-Binding Proteins/drug effects , Transcription Factors/metabolism , Gene Expression Profiling , Mutation , Transcription Factors/genetics
20.
Med Sci Monit ; 20: 1850-7, 2014 Oct 07.
Article in English | MEDLINE | ID: mdl-25287716

ABSTRACT

BACKGROUND: Chemotherapeutic insensitivity and tumor cell invasiveness are major obstacles to effectively treating muscle-invasive bladder cancer (MIBC). Recent reports show that microRNAs (miRNAs) play an important role in the chemotherapeutic response and disease progression of MIBC. Therefore, here we investigated the role of miR-150 in MIBC cells in vitro. MATERIAL AND METHODS: miR-150 expression was quantified by qRT-PCR in two MIBC cell lines (5637 and T24). After successful miR-150 inhibition by transfection, MTS and transwell assays were used to assess the MIBC's cisplatin sensitivity and cell invasiveness, respectively. The TargetScan database and a luciferase reporter system were used to identify whether the programmed cell death 4 protein (PDCD4) is a direct target of miR-150 in MIBC cells. RESULTS: miR-150 expression was found to be significantly increased in both MIBC cell lines, and treatment with a miR-150 inhibitor significantly sensitized MIBC cells to cisplatin and inhibited MIBC cell invasiveness. PDCD4 was identified as a direct target of miR-150 in MIBC cells, and increased PDCD4 expression via transfection with the pLEX-PDCD4 plasmid efficiently sensitized MIBC cells to cisplatin chemotherapy and inhibited MIBC cell invasiveness. CONCLUSIONS: This study provides novel evidence that miR-150 functions as a tumor promoter in reducing chemosensitivity and promoting invasiveness of MIBC cells via targeting PDCD4. Thus, modulation of the miR-150-PDCD4 axis shows promise as a therapeutic strategy for MIBC.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis Regulatory Proteins/drug effects , Cisplatin/pharmacology , MicroRNAs/physiology , Neoplasm Invasiveness , RNA-Binding Proteins/drug effects , Urinary Bladder Neoplasms/pathology , Apoptosis Regulatory Proteins/metabolism , Base Sequence , Cell Line, Tumor , DNA Primers , Disease Progression , Humans , RNA-Binding Proteins/metabolism , Urinary Bladder Neoplasms/metabolism
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