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Pain Jan 2024The persistence of inflammatory and neuropathic pain is poorly understood. We investigated a novel therapeutic paradigm by targeting gene networks that sustain or...
The persistence of inflammatory and neuropathic pain is poorly understood. We investigated a novel therapeutic paradigm by targeting gene networks that sustain or reverse persistent pain states. Our prior observations found that Sp1-like transcription factors drive the expression of TRPV1, a pain receptor, that is blocked in vitro by mithramycin A (MTM), an inhibitor of Sp1-like factors. Here, we investigate the ability of MTM to reverse in vivo models of inflammatory and chemotherapy-induced peripheral neuropathy (CIPN) pain and explore MTM's underlying mechanisms. Mithramycin reversed inflammatory heat hyperalgesia induced by complete Freund adjuvant and cisplatin-induced heat and mechanical hypersensitivity. In addition, MTM reversed both short-term and long-term (1 month) oxaliplatin-induced mechanical and cold hypersensitivity, without the rescue of intraepidermal nerve fiber loss. Mithramycin reversed oxaliplatin-induced cold hypersensitivity and oxaliplatin-induced TRPM8 overexpression in dorsal root ganglion (DRG). Evidence across multiple transcriptomic profiling approaches suggest that MTM reverses inflammatory and neuropathic pain through broad transcriptional and alternative splicing regulatory actions. Mithramycin-dependent changes in gene expression following oxaliplatin treatment were largely opposite to and rarely overlapped with changes in gene expression induced by oxaliplatin alone. Notably, RNAseq analysis revealed MTM rescue of oxaliplatin-induced dysregulation of mitochondrial electron transport chain genes that correlated with in vivo reversal of excess reactive oxygen species in DRG neurons. This finding suggests that the mechanism(s) driving persistent pain states such as CIPN are not fixed but are sustained by ongoing modifiable transcription-dependent processes.
Topics: Humans; Plicamycin; Oxaliplatin; Antineoplastic Agents; Neuralgia; Hyperalgesia; Ganglia, Spinal
PubMed: 37366593
DOI: 10.1097/j.pain.0000000000002972 -
Advanced Science (Weinheim,... Nov 2023Although the MAPK/MEK/ERK pathway is prevalently activated in colorectal cancer (CRC), MEK/ERK inhibitors show limited efficiency in clinic. As a downstream target of...
Although the MAPK/MEK/ERK pathway is prevalently activated in colorectal cancer (CRC), MEK/ERK inhibitors show limited efficiency in clinic. As a downstream target of MAPK, ELK4 is thought to work primarily by forming a complex with SRF. Whether ELK4 can serve as a potential therapeutic target is unclear and the transcriptional regulatory mechanism has not been systemically analyzed. Here, it is shown that ELK4 promotes CRC tumorigenesis. Integrated genomics- and proteomics-based approaches identified SP1 and SP3, instead of SRF, as cooperative functional partners of ELK4 at genome-wide level in CRC. Serum-induced phosphorylation of ELK4 by MAPKs facilitated its interaction with SP1/SP3. The pathological neoangiogenic factor LRG1 is identified as a direct target of the ELK4-SP1/SP3 complex. Furthermore, targeting the ELK4-SP1/SP3 complex by combination treatment with MEK/ERK inhibitor and the relatively specific SP1 inhibitor mithramycin A (MMA) elicited a synergistic antitumor effect on CRC. Clinically, ELK4 is a marker of poor prognosis in CRC. A 9-gene prognostic model based on the ELK4-SP1/3 complex-regulated gene set showed robust prognostic accuracy. The results demonstrate that ELK4 cooperates with SP1 and SP3 to transcriptionally regulate LRG1 to promote CRC tumorigenesis in an SRF-independent manner, identifying the ELK4-SP1/SP3 complex as a potential target for rational combination therapy.
Topics: Humans; Promoter Regions, Genetic; Gene Expression Regulation; Colorectal Neoplasms; Carcinogenesis; Mitogen-Activated Protein Kinase Kinases; ets-Domain Protein Elk-4; Glycoproteins
PubMed: 37786278
DOI: 10.1002/advs.202303378 -
Journal of Inorganic Biochemistry Mar 2016The antineoplastic and antibiotic natural product mithramycin (MTM) is used against cancer-related hypercalcemia and, experimentally, against Ewing sarcoma and lung...
The antineoplastic and antibiotic natural product mithramycin (MTM) is used against cancer-related hypercalcemia and, experimentally, against Ewing sarcoma and lung cancers. MTM exerts its cytotoxic effect by binding DNA as a divalent metal ion (Me(2+))-coordinated dimer and disrupting the function of transcription factors. A precise molecular mechanism of action of MTM, needed to develop MTM analogues selective against desired transcription factors, is lacking. Although it is known that MTM binds G/C-rich DNA, the exact DNA recognition rules that would allow one to map MTM binding sites remain incompletely understood. Towards this goal, we quantitatively investigated dimerization of MTM and several of its analogues, MTM SDK (for Short side chain, DiKeto), MTM SA-Trp (for Short side chain and Acid), MTM SA-Ala, and a biosynthetic precursor premithramycin B (PreMTM B), and measured the binding affinities of these molecules to DNA oligomers of different sequences and structural forms at physiological salt concentrations. We show that MTM and its analogues form stable dimers even in the absence of DNA. All molecules, except for PreMTM B, can bind DNA with the following rank order of affinities (strong to weak): MTM=MTM SDK>MTM SA-Trp>MTM SA-Ala. An X(G/C)(G/C)X motif, where X is any base, is necessary and sufficient for MTM binding to DNA, without a strong dependence on DNA conformation. These recognition rules will aid in mapping MTM sites across different promoters towards development of MTM analogues as useful anticancer agents.
Topics: Antibiotics, Antineoplastic; DNA; Dimerization; Plicamycin
PubMed: 26760230
DOI: 10.1016/j.jinorgbio.2015.12.011 -
Journal of Nanobiotechnology Sep 2021Sarcomas comprise a group of aggressive malignancies with very little treatment options beyond standard chemotherapy. Reposition of approved drugs represents an...
BACKGROUND
Sarcomas comprise a group of aggressive malignancies with very little treatment options beyond standard chemotherapy. Reposition of approved drugs represents an attractive approach to identify effective therapeutic compounds. One example is mithramycin (MTM), a natural antibiotic which has demonstrated a strong antitumour activity in several tumour types, including sarcomas. However, its widespread use in the clinic was limited by its poor toxicity profile.
RESULTS
In order to improve the therapeutic index of MTM, we have loaded MTM into newly developed nanocarrier formulations. First, polylactide (PLA) polymeric nanoparticles (NPs) were generated by nanoprecipitation. Also, liposomes (LIP) were prepared by ethanol injection and evaporation solvent method. Finally, MTM-loaded hydrogels (HG) were obtained by passive loading using a urea derivative non-peptidic hydrogelator. MTM-loaded NPs and LIP display optimal hydrodynamic radii between 80 and 105 nm with a very low polydispersity index (PdI) and encapsulation efficiencies (EE) of 92 and 30%, respectively. All formulations show a high stability and different release rates ranging from a fast release in HG (100% after 30 min) to more sustained release from NPs (100% after 24 h) and LIP (40% after 48 h). In vitro assays confirmed that all assayed MTM formulations retain the cytotoxic, anti-invasive and anti-stemness potential of free MTM in models of myxoid liposarcoma, undifferentiated pleomorphic sarcoma and chondrosarcoma. In addition, whole genome transcriptomic analysis evidenced the ability of MTM, both free and encapsulated, to act as a multi-repressor of several tumour-promoting pathways at once. Importantly, the treatment of mice bearing sarcoma xenografts showed that encapsulated MTM exhibited enhanced therapeutic effects and was better tolerated than free MTM.
CONCLUSIONS
Overall, these novel formulations may represent an efficient and safer MTM-delivering alternative for sarcoma treatment.
Topics: Animals; Anti-Bacterial Agents; Antineoplastic Agents; Chondrosarcoma; Drug Compounding; Female; Humans; Hydrogels; Liposomes; Mice; Mice, Nude; Nanoparticles; Plicamycin; Polyesters; Sarcoma
PubMed: 34488783
DOI: 10.1186/s12951-021-01008-x -
Science Advances Apr 2024Histopathological heterogeneity is a hallmark of prostate cancer (PCa). Using spatial and parallel single-nucleus transcriptomics, we report an androgen receptor...
Histopathological heterogeneity is a hallmark of prostate cancer (PCa). Using spatial and parallel single-nucleus transcriptomics, we report an androgen receptor (AR)-positive but neuroendocrine-null primary PCa subtype with morphologic and molecular characteristics of small cell carcinoma. Such small cell-like PCa (SCLPC) is clinically aggressive with low AR, but high stemness and proliferation, activity. Molecular characterization prioritizes protein translation, represented by up-regulation of many ribosomal protein genes, and SP1, a transcriptional factor that drives SCLPC phenotype and overexpresses in castration-resistant PCa (CRPC), as two potential therapeutic targets in AR-indifferent CRPC. An SP1-specific inhibitor, plicamycin, effectively suppresses CRPC growth in vivo. Homoharringtonine, a Food And Drug Administration-approved translation elongation inhibitor, impedes CRPC progression in preclinical models and patients with CRPC. We construct an SCLPC-specific signature capable of stratifying patients for drug selectivity. Our studies reveal the existence of SCLPC in admixed PCa pathology, which may mediate tumor relapse, and establish SP1 and translation elongation as actionable therapeutic targets for CRPC.
Topics: Male; Humans; Prostatic Neoplasms, Castration-Resistant; Receptors, Androgen; Neoplasm Recurrence, Local; Transcription Factors; Protein Biosynthesis; Cell Line, Tumor; Gene Expression Regulation, Neoplastic
PubMed: 38569039
DOI: 10.1126/sciadv.adm7098 -
Journal of Clinical Medicine Mar 2021Sarcomas are aggressive tumors which often show a poor response to current treatments. As a promising therapeutic alternative, we focused on mithramycin (MTM), a natural...
Sarcomas are aggressive tumors which often show a poor response to current treatments. As a promising therapeutic alternative, we focused on mithramycin (MTM), a natural antibiotic with a promising anti-tumor activity but also a relevant systemic toxicity. Therefore, the encapsulation of MTM in nano-delivery systems may represent a way to increase its therapeutic window. Here, we designed novel transfersomes and PLGA polymeric micelles by combining different membrane components (phosphatidylcholine, Span 60, Tween 20 and cholesterol) to optimize the nanoparticle size, polydispersity index (PDI) and encapsulation efficiency (EE). Using both thin film hydration and the ethanol injection methods we obtained MTM-loaded transferosomes displaying an optimal hydrodynamic diameter of 100-130 nm and EE values higher than 50%. Additionally, we used the emulsion/solvent evaporation method to synthesize polymeric micelles with a mean size of 228 nm and a narrow PDI, capable of encapsulating MTM with EE values up to 87%. These MTM nano-delivery systems mimicked the potent anti-tumor activity of free MTM, both in adherent and cancer stem cell-enriched tumorsphere cultures of myxoid liposarcoma and chondrosarcoma models. Similarly to free MTM, nanocarrier-delivered MTM efficiently inhibits the signaling mediated by the pro-oncogenic factor SP1. In summary, we provide new formulations for the efficient encapsulation of MTM which may constitute a safer delivering alternative to be explored in future clinical uses.
PubMed: 33806182
DOI: 10.3390/jcm10071358 -
American Journal of Cancer Research 2021SET Domain Bifurcated Histone Lysine Methyltransferase 1 (SETDB1, ESET, KMT1E) is a H3K9 methyltransferase involved in gene silencing. In recent years, SETDB1 has been... (Review)
Review
SET Domain Bifurcated Histone Lysine Methyltransferase 1 (SETDB1, ESET, KMT1E) is a H3K9 methyltransferase involved in gene silencing. In recent years, SETDB1 has been implicated as an oncogene in various cancers, highlighting a critical need to better understand the mechanisms underlying SETDB1 amplification, overexpression, and activation. In the following review, we first examine the history of SETDB1, starting from its discovery in 1999 and ending with recent findings. We follow with an outline of the structure and subcellular location of SETDB1, as well as potential mechanisms for regulation of its nuclear transport. Subsequently, we introduce SETDB1's various functions, including its roles in promyelocytic leukemia nuclear body (PML-NB) formation, the methylation and activation of Akt, the silencing of the androgen receptor (AR) gene, retroelement silencing, the inhibition of tumor suppressor p53, and its role in promoting intestinal differentiation and survival. The Cancer Cell Line Encyclopedia (CCLE) screened SETDB1 dependency in 796 cancer cell lines, identifying SETDB1 as a common essential gene in 531 of them, demonstrating that SETDB1 expression is critical for the survival of the majority of cancers. Therefore, we provide a detailed review of the oncogenic effects of SETDB1 overexpression in breast cancer, non-small cell lung cancer, prostate cancer, colorectal cancer, acute myeloid leukemia, glioma, melanoma, pancreatic ductal adenocarcinoma, liver cancer, nasopharyngeal carcinoma, gastric carcinoma, and endometrial cancer. Accordingly, we review several methods that have been used to target SETDB1, such as using Mithramycin A, Mithralog EC-8042, 3'-deazaneplanocin A (DZNep), and paclitaxel. Finally, we conclude by highlighting remaining gaps in knowledge and challenges surrounding SETDB1. Ultimately, our review captures the wide scope of findings on SETDB1's history, function, its implications in cancer, and provides suggestions for future research in the field.
PubMed: 34094655
DOI: No ID Found -
Clinical and Experimental Immunology Jan 1980Fluorescent probes can monitor events in lymphocytes stimulated by mitogens and antigens. Early activation is associated with conformational changes in membrane... (Review)
Review
Fluorescent probes can monitor events in lymphocytes stimulated by mitogens and antigens. Early activation is associated with conformational changes in membrane macromolecules, and has been studied by measurement of fluorescence intensity or polarization of the membrane-localizing probes ANS, NPN, DPH and TMRITC. Subsequent changes in cytoplasmic macromolecules have been detected by altered fluorescence polarization of intracellular fluorescein. Altered metabolic activity in the activated lymphocyte is also revealed by fluorescent probes: the increased red fluorescence of lysosomes seen by AO staining, is attributable to altered lysosome membrane permeability. AO fluorescence has also detected early changes in the nuclear nucleoprotein complex. The later synthesis of new DNA is readily demonstrated by increased staining with the nuclear probes AO, ethidium bromide, propidium iodide, mithramycin and the Hoechst dyes. Adaptation of fluorescent probe analyses to the now rapidly developing flow microfluorimeters is providing rapid and sensitive assays of lymphocyte stimulation. Such methods will permit routine detection of lymphocyte response to particular antigens or mitogens, as well as identification of antigenic substances by their stimulation of known reactive lymphocytes. Last but not least, fluorescent probes are providing new understanding of the cellular events and regulatory mechanisms associated with lymphocyte activation.
Topics: Acridine Orange; Anilino Naphthalenesulfonates; Animals; Cell Membrane; Cytoplasm; DNA; Diphenylhexatriene; Fluoresceins; Fluorescence Polarization; Fluorescent Dyes; Humans; In Vitro Techniques; Lymphocyte Activation; Membrane Fluidity; Microscopy, Fluorescence; Molecular Conformation; RNA
PubMed: 6156040
DOI: No ID Found -
Clinical Cancer Research : An Official... Mar 2016Specificity protein 1 (SP1) is an oncogenic transcription factor overexpressed in various human malignancies. This study sought to examine SP1 expression in malignant...
PURPOSE
Specificity protein 1 (SP1) is an oncogenic transcription factor overexpressed in various human malignancies. This study sought to examine SP1 expression in malignant pleural mesotheliomas (MPM) and ascertain the potential efficacy of targeting SP1 in these neoplasms.
EXPERIMENTAL DESIGN
qRT-PCR, immunoblotting, and immunohistochemical techniques were used to evaluate SP1 expression in cultured MPM cells and MPM specimens and normal mesothelial cells/pleura. MTS, chemotaxis, soft agar, β-galactosidase, and Apo-BrdUrd techniques were used to assess proliferation, migration, clonogenicity, senescence, and apoptosis in MPM cells following SP1 knockdown, p53 overexpression, or mithramycin treatment. Murine subcutaneous and intraperitoneal xenograft models were used to examine effects of mithramycin on MPM growth in vivo. Microarray, qRT-PCR, immunoblotting, and chromatin immunoprecipitation techniques were used to examine gene expression profiles mediated by mithramycin and combined SP1 knockdown/p53 overexpression and correlate these changes with SP1 and p53 levels within target gene promoters.
RESULTS
MPM cells and tumors exhibited higher SP1 mRNA and protein levels relative to control cells/tissues. SP1 knockdown significantly inhibited proliferation, migration, and clonogenicity of MPM cells. Mithramycin depleted SP1 and activated p53, dramatically inhibiting proliferation and clonogenicity of MPM cells. Intraperitoneal mithramycin significantly inhibited growth of subcutaneous MPM xenografts and completely eradicated mesothelioma carcinomatosis in 75% of mice. Mithramycin modulated genes mediating oncogene signaling, cell-cycle regulation, senescence, and apoptosis in vitro and in vivo. The growth-inhibitory effects of mithramycin in MPM cells were recapitulated by combined SP1 knockdown/p53 overexpression.
CONCLUSIONS
These findings provide preclinical rationale for phase II evaluation of mithramycin in patients with mesothelioma.
Topics: Animals; Apoptosis; Biomarkers, Tumor; Cell Proliferation; Cellular Senescence; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant; Mice; Middle Aged; Pleural Neoplasms; Plicamycin; RNA, Messenger; Sp1 Transcription Factor; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays
PubMed: 26459178
DOI: 10.1158/1078-0432.CCR-14-3379 -
Journal of the National Cancer Institute Jun 2011Chromosomal translocations generating oncogenic transcription factors are the hallmark of a variety of tumors, including many sarcomas. Ewing sarcoma family of tumors...
BACKGROUND
Chromosomal translocations generating oncogenic transcription factors are the hallmark of a variety of tumors, including many sarcomas. Ewing sarcoma family of tumors (ESFTs) are characterized by the t(11;22)(q24;q12) translocation that generates the Ewing sarcoma breakpoint region 1 and Friend leukemia virus integration 1 (EWS-FLI1) fusion transcription factor responsible for the highly malignant phenotype of this tumor. Although continued expression of EWS-FLI1 is believed to be critical for ESFT cell survival, a clinically effective small-molecule inhibitor remains elusive likely because EWS-FLI1 is a transcription factor and therefore widely felt to be "undruggable."
METHODS
We developed a high-throughput screen to evaluate more than 50 000 compounds for inhibition of EWS-FLI1 activity in TC32 ESFT cells. We used a TC32 cell-based luciferase reporter screen using the EWS-FLI1 downstream target NR0B1 promoter and a gene signature secondary screen to sort and prioritize the compounds. We characterized the lead compound, mithramycin, based on its ability to inhibit EWS-FLI1 activity in vitro using microarray expression profiling, quantitative reverse transcription-polymerase chain reaction, and immunoblot analysis, and in vivo using immunohistochemistry. We studied the impact of this inhibition on cell viability in vitro and on tumor growth in ESFT xenograft models in vivo (n = 15-20 mice per group). All statistical tests were two-sided.
RESULTS
Mithramycin inhibited expression of EWS-FLI1 downstream targets at the mRNA and protein levels and decreased the growth of ESFT cells at half maximal inhibitory concentrations between 10 (95% confidence interval [CI] = 8 to 13 nM) and 15 nM (95% CI = 13 to 19 nM). Mithramycin suppressed the growth of two different ESFT xenograft tumors and prolonged the survival of ESFT xenograft-bearing mice by causing a decrease in mean tumor volume. For example, in the TC32 xenograft model, on day 15 of treatment, the mean tumor volume for the mithramycin-treated mice was approximately 3% of the tumor volume observed in the control mice (mithramycin vs control: 69 vs 2388 mm(3), difference = 2319 mm(3), 95% CI = 1766 to 2872 mm(3), P < .001).
CONCLUSION
Mithramycin inhibits EWS-FLI1 activity and demonstrates ESFT antitumor activity both in vitro and in vivo.
Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cell Survival; DNA Damage; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; High-Throughput Screening Assays; Humans; Immunoblotting; Immunohistochemistry; Mice; Microscopy, Confocal; Oncogene Proteins, Fusion; Plicamycin; Protein Array Analysis; Proto-Oncogene Protein c-fli-1; RNA-Binding Protein EWS; Reverse Transcriptase Polymerase Chain Reaction; Sarcoma, Ewing; Transcription Factors; Transcription, Genetic; Translocation, Genetic; Transplantation, Heterologous
PubMed: 21653923
DOI: 10.1093/jnci/djr156