Background:
Polyamine levels are intricately controlled by biosynthetic, catabolic enzymes and antizymes. The complexity suggests that minute alterations in levels lead to profound abnormalities. We ...described the therapeutic course for a rare syndrome diagnosed by whole exome sequencing caused by gain-of-function variants in the C-terminus of ornithine decarboxylase (ODC), characterized by neurological deficits and alopecia.
Methods:
N-
acetylputrescine levels with other metabolites were measured using ultra-performance liquid chromatography paired with mass spectrometry and Z-scores established against a reference cohort of 866 children.
Results:
From previous studies and metabolic profiles, eflornithine was identified as potentially beneficial with therapy initiated on FDA approval. Eflornithine normalized polyamine levels without disrupting other pathways. She demonstrated remarkable improvement in both neurological symptoms and cortical architecture. She gained fine motor skills with the capacity to feed herself and sit with support.
Conclusions:
This work highlights the strategy of repurposing drugs to treat a rare disease.
Funding:
No external funding was received for this work.
Endometrial cancer (EC) is a common and deadly cancer in women and novel therapeutic approaches are urgently needed. Polyamines (putrescine, spermidine, spermine) are critical for mammalian cell ...proliferation and MYC coordinately regulates polyamine metabolism through ornithine decarboxylase (ODC). ODC is a MYC target gene and rate-limiting enzyme of polyamine biosynthesis and the FDA-approved anti-protozoan drug α-difluoromethylornithine (DFMO) inhibits ODC activity and induces polyamine depletion that leads to tumour growth arrest. Spermidine is required for the hypusine-dependent activation of eukaryotic translation initiation factors 5A1 (eIF5A1) and 5A2 (eIF5A2) and connects the MYC/ODC-induced deregulation of spermidine to eIF5A1/2 protein translation, which is increased during cancer cell proliferation. We show that eIF5A1 is significantly upregulated in EC cells compared to control cells (p=.000038) and that combined pharmacological targeting of ODC and eIF5A hypusination with cytostatic drugs DFMO and N1-guanyl-1,7-diaminoheptane (GC7), respectively, reduces eIF5A1 activation and synergistically induces apoptosis in EC cells. In vivo, DFMO/GC7 suppressed xenografted EC tumour growth in mice more potently than each drug alone compared to control (p=.002) and decreased putrescine (p=.045) and spermidine levels in tumour tissues. Our data suggest DFMO and GC7 combination therapy may be useful in the treatment or prevention of EC.
Calcineurin dephosphorylates nuclear factor of activated T cells transcription factors, thereby facilitating T cell-mediated immune responses. Calcineurin inhibitors are instrumental for ...immunosuppression after organ transplantation but may cause side effects, including hypertension and electrolyte disorders. Kidneys were recently shown to display activation of the furosemide-sensitive Na-K-2Cl cotransporter (NKCC2) of the thick ascending limb and the thiazide-sensitive Na-Cl cotransporter (NCC) of the distal convoluted tubule upon calcineurin inhibition using cyclosporin A (CsA). An involvement of major hormones like angiotensin II or arginine vasopressin (AVP) has been proposed. To resolve this issue, the effects of CsA treatment in normal Wistar rats, AVP-deficient Brattleboro rats, and cultured renal epithelial cells endogenously expressing either NKCC2 or NCC were studied. Acute administration of CsA to Wistar rats rapidly augmented phosphorylation levels of NKCC2, NCC, and their activating kinases suggesting intraepithelial activating effects. Chronic CsA administration caused salt retention and hypertension, along with stimulation of renin and suppression of renal cyclooxygenase 2, pointing to a contribution of endocrine and paracrine mechanisms at long term. In Brattleboro rats, CsA induced activation of NCC, but not NKCC2, and parallel effects were obtained in cultured cells in the absence of AVP. Stimulation of cultured thick ascending limb cells with AVP agonist restored their responsiveness to CsA. Our results suggest that the direct epithelial action of calcineurin inhibition is sufficient for the activation of NCC, whereas its effect on NKCC2 is more complex and requires concomitant stimulation by AVP.
Hexavalent chromium (Cr VI) has mutagenic and carcinogenic properties and causes severe health and environmental effects. The chromium’s adsorption equilibrium in aqueous media, its mechanisms, and ...different lignocellulosic wastes have been studied by many researchers. In this way, this paper provides a systematic, updated, and critical overview of Cr (IVI) adsorption by lignocellulosic waste adsorbent. Besides, analyzing the Cr (VI) problems in the aquatic environment addressed to lignocellulosic waste and its properties as adsorbent. Also, it was made a deep revision about important topics such as chemical regeneration and Cr (VI) recovery, characterization techniques, and interfering factors effects (e.g., pH, dosage). In addition, it was studied carefully the adsorption phenomena through several mathematical models of kinetics and isotherms and analyzed the thermodynamics results reported by an important number of research papers. Through this review, it was observed that the lignocellulosic wastes adsorption capacities usually range from 0.32 to 403.23 mg g
−1
, the adsorbent percentage removal after regenerating cycle ranged between 26.5 and 98.69%, and a greater performance of removing Cr (VI) occurs at pH range 1–6. The pseudo-second-order and Langmuir models were the models that presented the best adjustment of the experimental data for Cr (VI) adsorption, and the thermodynamic nature was spontaneous and endothermic for most cases. Further studies about lignocellulosic waste adsorbents lifecycle, stability, large-scale production, and production cost analysis are still necessary to determine the stability and efficacy of lignocellulosic wastes adsorbents in real effluent treatment.
High-risk neuroblastoma with N-Myc amplification remains a therapeutic challenge in paediatric oncology. Antagonism of pro-death Bcl-2 homology (BH) proteins to pro-survival BH members such as Mcl-1 ...and Bcl-2 has become a treatment approach, but previous studies suggest that a combined inhibition of Bcl-2 and Mcl-1 is necessary. TW-37 inhibits Mcl-1 and Bcl-2 with almost the same affinity. However, single-agent cytotoxicity of TW-37 in neuroblastoma cell lines has not been investigated.
Cell viability, apoptosis, proliferation and changes in growth properties were determined in SKNAS, IMR-5, SY5Y and Kelly cells after treatment with TW-37. After transfection with Mcl-1 or Bcl-2 siRNA, apoptosis and proliferation were investigated in Kelly cells. Mice with Kelly cell line xenografts were treated with TW-37 and tumor growth, survival and apoptosis were determined.
Cell lines with N-Myc amplification were more sensitive to TW-37 treatment, IC50 values for IMR-5 and Kelly cells being 0.28 μM and 0.22 μM, compared to SY5Y cells and SKNAS cells (IC50 0.96 μM and 0.83 μM). Treatment with TW-37 resulted in increased apoptosis and reduced proliferation rates, especially in IMR5 and Kelly cells. Bcl-2 as well as Mcl-1 knockdown induced apoptosis in Kelly cells. TW-37 led to a decrease in tumor growth and a favorable survival (p = 0.0379) in a Kelly neuroblastoma xenografts mouse model.
TW-37 has strong single-agent cytotoxicity in vitro and in vivo. Therefore, combined inhibition of Bcl-2/Mcl-1 by TW-37 in N-Myc amplified neuroblastoma may represent an interesting therapeutic strategy.
The ornithine decarboxylase 1 (ODC1) gene plays an important role in physiological and cell developmental processes including embryogenesis, organogenesis, and neoplastic cell growth. Here, we report ...an 32‐month‐old Caucasian female with a heterozygous de novo nonsense mutation in the ODC1 gene that leads to a premature abrogation of 14‐aa residues at the ODC protein c‐terminus. This is the first human case confirming similar symptoms observed in a transgenic ODC1 mouse model first described over 20 years ago. Phenotypic manifestations include macrosomia, macrocephaly, developmental delay, alopecia, spasticity, hypotonia, cutaneous vascular malformation, delayed visual maturation, and sensorineural hearing loss. We here describe for the first time a new pediatric disorder that is directly linked to a de novo pathogenic variant in the ODC1 gene. The ODC1 gene mutation (c.1342 A>T) was identified by whole‐exome sequencing and confirmed by Sanger sequencing. Red blood cells obtained from our patient showed elevated ODC protein and polyamine levels compared to healthy controls. Our autosomal dominant patient who carries this gain‐of‐function ODC1 mutation may benefit from treatment with α‐difluoromethylornithine, a well‐tolerated, U.S. Food and Drug Administration (FDA). FDA‐approved drug.
The epigenetic regulator lysine specific demethylase 1 (LSD1), a MYCN cofactor, cooperatively silences MYCN suppressor genes. Furthermore, LSD1 has been correlated with adverse effects in ...neuroblastic tumors by propagating an undifferentiated, malignant phenotype. We observed that high LSD1 mRNA expression in MYCN-expressing neuroblastoma (NB) correlated with poor prognosis, implicating LSD1 as an oncogenic accomplice in high-grade NB. Thus, LSD1 inhibition is a potential strategy for targeting treatment-resistant MYCN-expressing NB. Tranylcypromine-based covalent LSD1 inhibitors have demonstrated anti-tumor activity but are associated with undesirable off-target effects, such that only 2 non-covalent LSD1 inhibitors are in clinical trials. We now report 3 novel scaffolds for reversible LSD1 inhibition: 2-(arylsulfonamido)benzoic acid, N-(2-(1H-tetrazol-5-yl)phenyl)benzenesulfonamide and 2-(arylcarboxamido)benzoic acid analogues. The most active of these analogues, compound 48, exhibited potent and selective mixed reversible inhibition of LSD1 (IC50 = 0.58 μM) and significantly increased global H3K4me2 in NB cells. In addition, combination treatment with 48 and bortezomib in NB cells results in a synergistic effect.
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•High LSD1 expression in MYCN-expressing neuroblastoma leads to reduced survival.•In silico analysis led to identification of 3 new scaffolds for LSD1 inhibitor design.•The most active reversible LSD1 inhibitor was compound 48 (IC50 0.58 μM).•Compound 48 was selective for LSD1 and increased cellular H3K4me2 in vitro.•48 at 100 nM in combination with bortezomib was synergistic in 2 neuroblastoma lines.
Ornithine decarboxylase (ODC) is the rate-limiting enzyme for the synthesis of polyamines (PAs). PAs are oncometabolites that are required for proliferation, and pharmaceutical ODC inhibition is ...pursued for the treatment of hyperproliferative diseases, including cancer and infectious diseases. The most potent ODC inhibitor is 1-amino-oxy-3-aminopropane (APA). A previous crystal structure of an ODC-APA complex indicated that APA non-covalently binds ODC and its cofactor pyridoxal 5-phosphate (PLP) and functions by competing with the ODC substrate ornithine for binding to the catalytic site. We have revisited the mechanism of APA binding and ODC inhibition through a new crystal structure of APA-bound ODC, which we solved at 2.49 Å resolution. The structure unambiguously shows the presence of a covalent oxime between APA and PLP in the catalytic site, which we confirmed in solution by mass spectrometry. The stable oxime makes extensive interactions with ODC but cannot be catabolized, explaining APA's high potency in ODC inhibition. In addition, we solved an ODC/PLP complex structure with citrate bound at the substrate-binding pocket. These two structures provide new structural scaffolds for developing more efficient pharmaceutical ODC inhibitors.
Label-free detection of core-multishell (CMS) nanocarriers and the anti-inflammatory drug dexamethasone is reported. Selective excitation by tunable soft X-rays in the O 1s-regime is used for probing ...either the CMS nanocarrier or the drug. Furthermore, the drug loading efficiency into CMS nanocarriers is determined by X-ray spectroscopy. The drug-loaded nanocarriers were topically applied to human skin explants providing insights into the penetration and drug release processes. It is shown that the core-multishell nanocarriers remain in the stratum corneum when applied for 100min to 1000min. Dexamethasone, if applied topically to human ex vivo skin explants using different formulations, shows a vehicle-dependent penetration behavior. Highest local drug concentrations are found in the stratum corneum as well as in the viable epidermis. If the drug is loaded to core-multishell nanocarriers, the concentration of the free drug is low in the stratum corneum and is enhanced in the viable epidermis as compared to other drug formulations. The present results provide insights into the penetration of drug nanocarriers as well as the mechanisms of controlled drug release from CMS nanocarriers in human skin. They are also compared to related work using dye-labeled nanocarriers and dyes that were used as model drugs.
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Risk behaviors such as substance use or deviance are often limited to the early stages of the life course. Whereas the onset of risk behavior is well studied, less is currently known about the ...decline and timing of cessation of risk behaviors of different domains during young adulthood. Prevalence and longitudinal developmental patterning of alcohol use, drinking to the point of drunkenness, smoking, cannabis use, deviance, and HIV-related sexual risk behavior were compared in a Swiss community sample (N = 2,843). Using a longitudinal cohort-sequential approach to link multiple assessments with 3 waves of data for each individual, the studied period spanned the ages of 16 to 29 years. Although smoking had a higher prevalence, both smoking and drinking up to the point of drunkenness followed an inverted U-shaped curve. Alcohol consumption was also best described by a quadratic model, though largely stable at a high level through the late 20s. Sexual risk behavior increased slowly from age 16 to age 22 and then remained largely stable. In contrast, cannabis use and deviance linearly declined from age 16 to age 29. Young men were at higher risk for all behaviors than were young women, but apart from deviance, patterning over time was similar for both sexes. Results about the timing of increase and decline as well as differences between risk behaviors may inform tailored prevention programs during the transition from late adolescence to adulthood.
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