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Oncogene Dec 2004In the present work, we show that mithramycin A, a drug that is currently used for the treatment of patients with Paget's disease of the bone as well as with several...
In the present work, we show that mithramycin A, a drug that is currently used for the treatment of patients with Paget's disease of the bone as well as with several forms of cancer, is a strong activator of the tumor suppressor p53 protein in human hepatoma cells. The time course of p53 activation by mithramycin A was similar to the known chemotherapeutic compound 5-fluorouracil (5-FU). Both 5-FU and mithramycin A induced site-specific phosphorylation of p53 at serine 15. However, in contrast to 5-FU, mithramycin A failed to activate p53 target genes including the cell cycle inhibitor p21Cip1 gene as well as the proapoptotic genes PUMA (p53-upregulated mediator of apotosis) and BAK (bcl2-homologous antagonist/killer) and blocked the induction of the above genes by 5-FU. Using transactivation assays in Sp1-deficient cells, we showed that mithramycin A inhibited the transcriptional activation of the p21Cip1 and PUMA promoters by Sp1 and p53. Using chromatin immunoprecipitation assays and a novel protein-protein interaction assay based on biotinylation in vivo, we established that 5-FU enhanced the formation of p53-Sp1 complexes in solution and the subsequent recruitment of both factors to the p21Cip1 promoter. Mithramycin A also enhanced the recruitment of p53 to the distal p21Cip1 promoter but totally blocked the recruitment of Sp1 to the proximal p21Cip1 promoter. Our findings suggest that inhibition of Sp1 binding to the promoters of several p53 target genes, such as the p21Cip1 gene as well as certain proapoptotic genes, by mithramycin A, prevents the transcriptional induction of these genes by p53 and propose a mechanism that could account for some of the tumor suppressing and antiapoptotic effects of mithramycin A.
Topics: Base Sequence; Binding Sites; Carcinoma, Hepatocellular; Cell Cycle Proteins; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p21; DNA Damage; DNA Primers; Humans; Liver Neoplasms; Plicamycin; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; Sp1 Transcription Factor; Transcription, Genetic; Tumor Suppressor Protein p53
PubMed: 15489892
DOI: 10.1038/sj.onc.1208141 -
Clinical and Experimental Pharmacology... Oct 2018Chemotherapy-induced cognitive changes is a major burden on a substantial number of cancer survivors. The mechanism of this sequel is unknown. In this study, we followed...
Chemotherapy-induced cognitive changes is a major burden on a substantial number of cancer survivors. The mechanism of this sequel is unknown. In this study, we followed long-term effects of early in life mithramycin (MTR) treatment on behaviour and on the normal course of alterations of gene expression in brain. Between post-natal days (PND) 7 and 10, male rats were divided into 2 groups, 1 receiving MTR (0.1 mg/kg s.c. per day) and the other receiving saline. At PND11, frontal cortex tissue samples were dissected from 4 rats from each group. At PND 65 the remaining rats underwent behavioural tests after which all the rats were decapitated and their prefrontal cortex incised. Rats treated transiently with MTR early in life, showed impairments in spatial working memory and anxious-like behaviour in adulthood. The immediate molecular effect of MTR was expressed in a limited number of altered genes of different unconnected trajectories, which were simultaneously distorted by the drug. In contrast, 3 months later we observed a change in the expression of more than 1000 genes that converged into specific cellular processes. Time-dependent gene expression dynamics of several genes was significantly different between treated and untreated rats. The differences in the total number of altered genes and in gene expression trends, immediately and long after MTR treatment cessation, suggest the evolution of a new cellular homeostatic set point, which can lead to behavioural abnormalities following chemotherapy treatment.
Topics: Animals; Anxiety; Cognitive Dysfunction; Gene Expression Regulation; Male; Memory, Short-Term; Phenotype; Plicamycin; Rats; Spatial Memory
PubMed: 29851136
DOI: 10.1111/1440-1681.12975 -
The American Journal of the Medical... Jul 1986A 58-year-old black woman with IgD multiple myeloma developed a hemorrhagic diathesis within 48 hours after receiving mithramycin (20 micrograms/kg/day) for therapy of...
A 58-year-old black woman with IgD multiple myeloma developed a hemorrhagic diathesis within 48 hours after receiving mithramycin (20 micrograms/kg/day) for therapy of hypercalcemia. Her coagulation studies were characterized by prolonged prothrombin, partial thromboplastin, thrombin, and reptilase clotting times. Her plasma and partially purified fibrinogen were inhibitory to the clotting of normal plasma and fibrinogen. The patient's isolated fibrinogen showed a normal rate of fibrinopeptide release, but her fibrin monomer aggregation was markedly abnormal. These studies document the development of a dysfibrinogenemia secondary to mithramycin toxicity.
Topics: Afibrinogenemia; Blood Coagulation Tests; Female; Hemorrhagic Disorders; Humans; Hypercalcemia; Middle Aged; Multiple Myeloma; Plicamycin
PubMed: 2940861
DOI: 10.1097/00000441-198607000-00011 -
Journal of Natural Products Jan 1999A reinvestigation of the structure of mithramycin, the principal product of Streptomyces argillaceus ATCC 12956, is reported. The structure elucidation was carried out...
A reinvestigation of the structure of mithramycin, the principal product of Streptomyces argillaceus ATCC 12956, is reported. The structure elucidation was carried out with mithramycin decaacetate (4) using 2D NMR methods, including TOCSY, HMBC, and HSQC experiments. The work resulted in structure 3being confirmed for mithramycin.
Topics: Antibiotics, Antineoplastic; Carbohydrate Sequence; Magnetic Resonance Spectroscopy; Molecular Sequence Data; Molecular Structure; Plicamycin
PubMed: 9917296
DOI: 10.1021/np980355k -
British Journal of Cancer May 2004In this report we show that mithramycin considerably increases the direct cytotoxic effect of tumour necrosis factor (TNF) on tumour cells in vitro. Sensitisation to...
In this report we show that mithramycin considerably increases the direct cytotoxic effect of tumour necrosis factor (TNF) on tumour cells in vitro. Sensitisation to TNF-induced apoptosis was prevented by the broad caspase inhibitor zVAD-fmk, whereas overexpression of Bcl-2 had no effect. Mithramycin also potentiated cell death induced by Fas agonistic antibodies. In contrast, mithramycin reduced the percentage of cells undergoing apoptosis due to factor withdrawal. TNF-induced activation of NF-kappaB (NF-kappaB)-dependent gene expression was not modulated by mithramycin treatment. Concomitantly with the increased sensitivity, the protein level of the short-spliced cFLIP variant was downregulated. These results indicate that mithramycin enhances TNF-induced cell death in an NF-kappaB-independent manner, and suggest that the Fas-associated death domain protein plays a crucial role in the TNF-sensitising effect of mithramycin.
Topics: Adaptor Proteins, Signal Transducing; Apoptosis; Carrier Proteins; Drug Resistance, Neoplasm; Fas-Associated Death Domain Protein; Gene Expression Regulation, Neoplastic; Humans; Leukemia, Erythroblastic, Acute; Leukemia, Promyelocytic, Acute; Plicamycin; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha; fas Receptor
PubMed: 15138489
DOI: 10.1038/sj.bjc.6601824 -
Experimental Cell Research Dec 2023The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causative of the ongoing coronavirus disease 2019 (COVID-19) pandemic. The SARS-CoV-2 Spike protein...
The anti-SARS-CoV-2 BNT162b2 vaccine suppresses mithramycin-induced erythroid differentiation and expression of embryo-fetal globin genes in human erythroleukemia K562 cells.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causative of the ongoing coronavirus disease 2019 (COVID-19) pandemic. The SARS-CoV-2 Spike protein (S-protein) plays an important role in the early phase of SARS-CoV-2 infection through efficient interaction with ACE2. The S-protein is produced by RNA-based COVID-19 vaccines, that were fundamental for the reduction of the viral spread within the population and the clinical severity of COVID-19. However, the S-protein has been hypothesized to be responsible for damaging cells of several tissues and for some important side effects of RNA-based COVID-19 vaccines. Considering the impact of COVID-19 and SARS-CoV-2 infection on the hematopoietic system, the aim of this study was to verify the effect of the BNT162b2 vaccine on erythroid differentiation of the human K562 cell line, that has been in the past intensively studied as a model system mimicking some steps of erythropoiesis. In this context, we focused on hemoglobin production and induced expression of embryo-fetal globin genes, that are among the most important features of K562 erythroid differentiation. We found that the BNT162b2 vaccine suppresses mithramycin-induced erythroid differentiation of K562 cells. Reverse-transcription-qPCR and Western blotting assays demonstrated that suppression of erythroid differentiation was associated with sharp inhibition of the expression of α-globin and γ-globin mRNA accumulation. Inhibition of accumulation of ζ-globin and ε-globin mRNAs was also observed. In addition, we provide in silico studies suggesting a direct interaction between SARS-CoV-2 Spike protein and Hb Portland, that is the major hemoglobin produced by K562 cells. This study thus provides information suggesting the need of great attention on possible alteration of hematopoietic parameters following SARS-CoV-2 infection and/or COVID-19 vaccination.
Topics: Humans; K562 Cells; Plicamycin; COVID-19 Vaccines; BNT162 Vaccine; Leukemia, Erythroblastic, Acute; COVID-19; SARS-CoV-2; Hemoglobins; RNA, Messenger; Erythroid Cells
PubMed: 37944576
DOI: 10.1016/j.yexcr.2023.113853 -
Biochemical and Biophysical Research... Jun 1992Mithramycin is a DNA-binding antibiotic that has been reported to selectively affect c-myc expression [Snyder, R. C. et al., (1991) Biochemistry 30, 4290-4297]. We used...
Mithramycin is a DNA-binding antibiotic that has been reported to selectively affect c-myc expression [Snyder, R. C. et al., (1991) Biochemistry 30, 4290-4297]. We used in vitro transcription to investigate the specificity of mithramycin action. We found that mithramycin inhibited transcription from the human c-myc P1 and P2 promoters, as well as from a minimal adenovirus-2 major late promoter, with equal efficiencies. Mithramycin also inhibited transcription elongation by creating kinetic blockades to the passage of RNA polymerase II. These data suggest that mithramycin may inhibit transcription non-specifically by affecting general processes such as transcription elongation.
Topics: Genes, myc; In Vitro Techniques; Plicamycin; Promoter Regions, Genetic; RNA Polymerase II; Transcription, Genetic
PubMed: 1535193
DOI: 10.1016/0006-291x(92)91660-i -
Apoptosis : An International Journal on... Jan 2006Mithramycin A (MMA, trade name Plicamycin) can facilitate TNFalpha- (Tumor Necrosis Factor) and Fas ligand-induced apoptosis. Besides, several drugs play their...
Mithramycin A (MMA, trade name Plicamycin) can facilitate TNFalpha- (Tumor Necrosis Factor) and Fas ligand-induced apoptosis. Besides, several drugs play their anticancer effect through Fas apoptotic pathway. So we investigated the effect of MMA on Fas signaling. In this study we show that MMA induces apoptosis in Fas sensitive Jurkat cells and Fas resistant KG1a cells. This effect involves Fas apoptotic pathway: cell exposure to MMA leads to Fas clustering at the cell surface, DISC (Death Inducing Signaling Complex) formation and caspase cleavage. This phenomenon is independent of Fas ligand/Fas interaction and blockade of Fas death pathway partially inhibits MMA-induced apoptosis. Moreover the activation of Fas apoptotic pathway by MMA is correlated to the modulation of c-Flip(L) expression. Finally, pre-treatment with sub-lethal doses of MMA sensitizes KG1a cells to chemotherapeutic agents. Thus all these results may have important implications to improve clinical treatments.
Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Death Domain Receptor Signaling Adaptor Proteins; Drug Resistance, Neoplasm; Fas Ligand Protein; Humans; Jurkat Cells; Leukemia; Plicamycin; Signal Transduction; fas Receptor
PubMed: 16374547
DOI: 10.1007/s10495-005-3089-z -
Therapie Der Gegenwart Jul 1979
Review
Topics: Animals; Confusion; Constipation; Dose-Response Relationship, Drug; Humans; Hypercalcemia; Hyperparathyroidism; Phosphates; Plicamycin; Polyuria; Potassium; Rats; Specific Gravity; Urine
PubMed: 158229
DOI: No ID Found -
Nucleic Acids Research Oct 2016Transcription factors have been considered undruggable, but this paradigm has been recently challenged. DNA binding natural product mithramycin (MTM) is a potent...
Transcription factors have been considered undruggable, but this paradigm has been recently challenged. DNA binding natural product mithramycin (MTM) is a potent antagonist of oncogenic transcription factor EWS-FLI1. Structural details of MTM recognition of DNA, including the FLI1 binding sequence GGA(A/T), are needed to understand how MTM interferes with EWS-FLI1. We report a crystal structure of an MTM analogue MTM SA-Trp bound to a DNA oligomer containing a site GGCC, and two structures of a novel analogue MTM SA-Phe in complex with DNA. MTM SA-Phe is bound to sites AGGG and GGGT on one DNA, and to AGGG and GGGA(T) (a FLI1 binding site) on the other, revealing how MTM recognizes different DNA sequences. Unexpectedly, at sub-micromolar concentrations MTMs stabilize FLI1-DNA complex on GGAA repeats, which are critical for the oncogenic function of EWS-FLI1. We also directly demonstrate by nuclear magnetic resonance formation of a ternary FLI1-DNA-MTM complex on a single GGAA FLI1/MTM binding site. These biochemical and structural data and a new FLI1-DNA structure suggest that MTM binds the minor groove and perturbs FLI1 bound nearby in the major groove. This ternary complex model may lead to development of novel MTM analogues that selectively target EWS-FLI1 or other oncogenic transcription factors, as anti-cancer therapeutics.
Topics: Base Sequence; DNA; Models, Molecular; Molecular Conformation; Molecular Structure; Oligodeoxyribonucleotides; Plicamycin; Protein Binding; Protein Interaction Domains and Motifs; Proto-Oncogene Protein c-fli-1; Structure-Activity Relationship
PubMed: 27587584
DOI: 10.1093/nar/gkw761