Dimer-tetramer transition controls RUNX1/ETO leukemogenic activity

Blood ◽  
2010 ◽  
Vol 116 (4) ◽  
pp. 603-613 ◽  
Author(s):  
Christian Wichmann ◽  
Yvonne Becker ◽  
Linping Chen-Wichmann ◽  
Vitali Vogel ◽  
Anna Vojtkova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hot Spot ◽  
Chromosomal Translocation ◽  
Structural Motif ◽  
In Vivo Studies ◽  
Tetramerization Domain ◽  
The Stability ◽  
Transplantation Model

Abstract RUNX1/ETO, the fusion protein resulting from the chromosomal translocation t(8;21), is one of the most frequent translocation products in acute myeloid leukemia. Several in vitro and in vivo studies have shown that the homo-tetramerization domain of ETO, the nervy homology region 2 (NHR2), is essential for RUNX1/ETO oncogenic activity. We analyzed the energetic contribution of individual amino acids within the NHR2 to RUNX1/ETO dimer-tetramer transition and found a clustered area of 5 distinct amino acids with strong contribution to the stability of tetramers. Substitution of these amino acids abolishes tetramer formation without affecting dimer formation. Similar to RUNX1/ETO monomers, dimers failed to bind efficiently to DNA and to alter expression of RUNX1-dependent genes. RUNX1/ETO dimers do not block myeloid differentiation, are unable to enhance the self-renewal capacity of hematopoietic progenitors, and fail to induce leukemia in a murine transplantation model. Our data reveal the existence of an essential structural motif (hot spot) at the NHR2 dimer-tetramer interface, suitable for a molecular intervention in t(8;21) leukemias.

scholarly journals The behaviour of thiomolybdates in in vitro systems

1979 ◽  
Vol 41 (2) ◽  
pp. 403-405 ◽  
Author(s):  
K. M. Weber ◽  
D. D. Leaver ◽  
A. G. Wedd
Keyword(s):  
Copper Metabolism ◽  
Hydrogen Ion ◽  
In Vivo Studies ◽  
In Vitro Systems ◽  
The Stability

The stability of potassium tetrathiomolybdate was studied in vitro using solutions with molybdenum, hydrogen ion and phosphate concentrations similar to those normally found in the rumen. Under these conditions K2[MoS4] hydrolysed rapidly and as a result the solution contained [MoS4]2−, [MoOS3]2−, [MoO2S2]2−, [HS]− and H2S in equilibrium. In view of this hydrolysis, in vivo studies of thiomolybdate on copper metabolism of sheep should not exclude the possibility that either sulphide or molybdate is responsible for any observed effect.

scholarly journals Preparation and Preliminary Evaluation of Novel β-Cyclodextrin/IUDR Prodrug Formulations

2008 ◽  
Vol 11 (2) ◽  
pp. 32 ◽  
Author(s):  
Leonard I. Wiebe ◽  
Xiao-Hong Yang ◽  
Shradha Singh ◽  
Jim Diakur
Keyword(s):  
Inclusion Complexes ◽  
In Vivo Studies ◽  
Preliminary Evaluation ◽  
Target Tissue ◽  
Molar Ratios ◽  
Nmr Spectrometry ◽  
Complex Approach ◽  
The Stability

PURPOSE. Iododeoxyuridine (IUdR) has a very short in vivo half-life and consequently achieves low target-tissue concentrations with concomitant lower efficacy than would be predicted from in vitro studies. This work reports the preparation of IUdR:?-cyclodextrin (?-CyD) inclusion complexes designed to reduce in vivo inactivation of IUdR. METHODS. IUdR was derivatized with either 1-adamantanecarbonyl chloride or 4-(1-adamantyl-carbamoyl)butanoic acid, to prepare 5’-O-(1-adamantoyl)-5-iodo-2’-deoxyuridine 1 and 5’-O-(4-(1-adamantylcarbamoyl)butoyl)-5-iodo-2’-deoxy-uridine 4, respectively. ?-CyD complexes 5 and 6 were formed by vigorous stirring of 1:1 solutions of ?-CyD and 1 or 4, respectively, in D2O under argon. Complexation was inferred from DSC, powder x-ray diffractometry and NMR spectrometry. The dissociation of 5 in water and under cholesterol challenge, and the effect of complexation on the stability of 1 was determined by incubation in plasma. RESULTS. IUdR coupling with adamantanecarbonyl chloride proceeded smoothly to afford 1 (69 %) and the di-substituted derivative, 3’,5’-di-O-(1-adamantoyl)-5-iodo-2’-deoxyuridine 2 (8 %); 4 was obtained in 42 % yield. The formation of 1:1 complexes 5 and 6 was inferred from NMR chemical shift data. In serum, 1 was 90 % hydrolyzed to IUdR in 30 min, compared to 10 % hydrolysis of 1 to IUdR when from complex 5. CONCLUSIONS. Inclusion complexes were formed between ?-CyD and adamantamine-IUdR conjugates at 1:1 molar ratios. The complex 5 was resistant to dissociation by cholesterol challenge, and 5 was more slowly converted to IUdR than non-complexed 1. In vivo studies are required to further exploit the ?-CyD inclusion complex approach for improved delivery of nucleoside derivatives.

scholarly journals SPZ1 promotes deregulation of Bim to boost apoptosis resistance in colorectal cancer

2020 ◽  
Vol 134 (2) ◽  
pp. 155-167
Author(s):  
Xiao-Yu Liu ◽  
Chang-Bo Zheng ◽  
Teng Wang ◽  
Jian Xu ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Growth ◽  
Clinical Stage ◽  
In Vivo Studies ◽  
Apoptosis Resistance ◽  
Advanced Clinical Stage ◽  
Helix Loop Helix ◽  
The Stability

Abstract Colorectal cancer (CRC) is the third most common malignancies in adults. Similar to other solid tumors, CRC cells show increased proliferation and suppressed apoptosis during the development and progression of the disease. Previous studies have shown that a novel tumor oncogene, spermatogenic basic helix-loop-helix transcription factor zip 1 (SPZ1), can promote proliferation. However, it is unclear whether SPZ1 plays a role in suppressing apoptosis, and the molecular mechanism behind SPZ1’s suppression of apoptosis in CRC remains unclear. Here, we found that silencing endogenous SPZ1 inhibits cell growth and induces apoptosis, and overexpression of SPZ1 promotes cell growth. These findings were corroborated by in vitro and in vivo studies. Interestingly, SPZ1 overexpressing cells were resistant to 5-fluorouracil, a drug commonly used to treat cancer. Moreover, knocking down SPZ1 led to the activation of caspase through the deregulation of Bim by ERK1/2, we found that CRC tissues had significantly higher SPZ1 and lower Bim expression, and SPZ1HBimL were associated with advanced clinical stage of CRC. Collectively, our findings demonstrate that SPZ1 contributes to tumor progression by limiting apoptosis. SPZ1 reduces apoptosis by altering the stability of Bim, suggesting SPZ1 may serve as a biomarker and therapeutic target for CRC.

scholarly journals In-Silico Evaluation of Tiryaq-E-Wabai, an Unani Formulation for its Potency against SARS-CoV-2 Spike Glycoprotein and Main Protease

2021 ◽  
Vol 11 (4-S) ◽  
pp. 86-100
Author(s):  
N ZAHEER AHMED ◽  
DICKY JOHN DAVIS ◽  
NOMAN ANWAR ◽  
ASIM ALI KHAN ◽  
RAM PRATAP MEENA ◽  
...  
Keyword(s):  
In Silico ◽  
Dynamics Simulation ◽  
In Vivo Studies ◽  
Spike Glycoprotein ◽  
Unani Medicine ◽  
Main Protease ◽  
Pubchem Database ◽  
The Stability

COVID-19 was originated in Wuhan, China, in December 2019 and has been declared a pandemic disease by WHO. The number of infected cases continues unabated and so far, no specific drug approved for targeted therapy. Hence, there is a need for drug discovery from traditional medicine. Tiryaq-e-Wabai is a well-documented formulation in Unani medicine for its wide use as prophylaxis during epidemics of cholera, plague and other earlier epidemic diseases. The objective of the current study is to generate in-silico evidence and evaluate the potency of Tiryaq-e-Wabai against SARS-CoV-2 spike (S) glycoprotein and main protease (3CLpro). The structures of all phytocompounds used in this study were retrieved from PubChem database and some were built using Marvin Sketch. The protein structure of the SARS-CoV-2 S glycoprotein and 3CLpro was retrieved from the PDB ID: 6LZG and 7BQY respectively. AutoDock Vina was used to predict top ranking poses with best scores. The results of the molecular docking showed that phytocompounds of Tiryaq-e-Wabai exhibited good docking power with spike glycoprotein and 3CLpro. Among tested compounds Crocin from Zafran and Aloin A from Sibr showed strong binding to spike glycoprotein and 3CLpro respectively. Molecular dynamics simulation confirmed the stability of the S glycoprotein-Crocin and 3CLpro-Aloin A complexes. The Unani formulation Tiryaq-e-Wabai has great potential to inhibit the SARS-CoV-2, which have to be substantiated with further in-vitro and in-vivo studies. Keywords: In-silico study, SARS-CoV-2, Tiryaq-e-Wabai, Unani formulation, Crocin, Aloin A

Role of excitatory amino acids in regulation of rat pial microvasculature

1994 ◽  
Vol 266 (1) ◽  
pp. R158-R163 ◽  
Author(s):  
Q. F. Huang ◽  
A. Gebrewold ◽  
A. Zhang ◽  
B. T. Altura ◽  
B. M. Altura
Keyword(s):  
Amino Acids ◽  
Nmda Receptor ◽  
Excitatory Amino Acids ◽  
Experimental Studies ◽  
In Vivo Studies ◽  
Small Blood Vessel ◽  
Mk 801 ◽  
Pial Arterioles

Recently, attention has been drawn to the possibility that excitatory amino acids (EAAs) may play an important role in the pathogenesis of hypoxic-ischemic neuronal injury. Exaggerated release of EAAs and excessive stimulation of N-methyl-D-aspartate (NMDA) receptors and other EAA receptors have been suggested to contribute to neuronal death in ischemia and anoxia. A number of in vitro and in vivo experimental studies have shown that EAA-receptor antagonists exert a protective effect on the brain after cerebral ischemia. Because neurons are in close apposition to small intracerebral vessels, synaptically released EAAs might also regulate small blood vessel function. With the use of quantitative television microscopic observations, in vivo studies were undertaken on pial arterioles of rats. Perivascular administration of cumulative doses (10(-7)-10(-2) M) of L-glycine, L-glutamate, L-aspartate, and NMDA on the pial microvessels resulted in concentration-dependent constriction of pial arterioles (5-30% decreases in diameter) and cerebrovasospasm; the relative order of potency was aspartate > NMDA > glycine > glutamate. High concentrations of EAAs often resulted in rupture of postcapillary venules. No amine or opiate antagonist or cyclooxygenase inhibitor prevented or attenuated the effects of these putative EAAs. EAA-induced constriction and spasm of pial arterioles as well as rupture of venules could, however, be blocked by the noncompetitive NMDA-receptor antagonist MK-801 and by Mg2+. MK-801 also produced a concentration-dependent relaxation on normal pial arterioles. These results are compatible with the idea that a specific NMDA-receptor complex (RC) exists in rat cortical microvessels, which subserves vasoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Cochaperone Interactions in Export of the Type III Needle Component PscF of Pseudomonas aeruginosa

2010 ◽  
Vol 192 (14) ◽  
pp. 3801-3808 ◽  
Author(s):  
Sophie Plé ◽  
Viviana Job ◽  
Andréa Dessen ◽  
Ina Attree
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Complex Formation ◽  
Hot Spot ◽  
Protein Stabilization ◽  
Site Directed Mutagenesis ◽  
Surface Stability ◽  
Type Iii

ABSTRACT Type III secretion (T3S) systems allow the export and translocation of bacterial effectors into the host cell cytoplasm. Secretion is accomplished by an 80-nm-long needle-like structure composed, in Pseudomonas aeruginosa, of the polymerized form of a 7-kDa protein, PscF. Two proteins, PscG and PscE, stabilize PscF within the bacterial cell before its export and polymerization. In this work we screened the 1,320-Å2 interface between the two chaperones, PscE and PscG, by site-directed mutagenesis and determined hot spot regions that are important for T3S function in vivo and complex formation in vitro. Three amino acids in PscE and five amino acids in PscG, found to be relevant for complex formation, map to the central part of the interacting surface. Stability assays on selected mutants performed both in vitro on purified PscE-PscG complexes and in vivo on P. aeruginosa revealed that PscE is a cochaperone that is essential for the stability of the main chaperone, PscG. Notably, when overexpressed from a bicistronic construct, PscG and PscF compensate for the absence of PscE in cytotoxic P. aeruginosa. These results show that all of the information needed for needle protein stabilization and folding, its presentation to the T3 secreton, and its export is present within the sequence of the PscG chaperone.

Amino Acid Degrading Enzymes and their Application in Cancer Therapy

2019 ◽  
Vol 26 (3) ◽  
pp. 446-464 ◽  
Author(s):  
Vadim S. Pokrovsky ◽  
Olga E. Chepikova ◽  
Denis Zh. Davydov ◽  
Andrey A. Zamyatnin Jr ◽  
Alexander N. Lukashev ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cancer Therapy ◽  
Cancer Treatment ◽  
Arginine Deiminase ◽  
In Vivo Studies ◽  
Degrading Enzymes ◽  
Essential Components

Background:Amino acids are essential components in various biochemical pathways. The deprivation of certain amino acids is an antimetabolite strategy for the treatment of amino acid-dependent cancers which exploits the compromised metabolism of malignant cells. Several studies have focused on the development and preclinical and clinical evaluation of amino acid degrading enzymes, namely L-asparaginase, L-methionine γ-lyase, L-arginine deiminase, L-lysine α-oxidase. Further research into cancer cell metabolism may therefore define possible targets for controlling tumor growth.Objective:The purpose of this review was to summarize recent progress in the relationship between amino acids metabolism and cancer therapy, with a particular focus on Lasparagine, L-methionine, L-arginine and L-lysine degrading enzymes and their formulations, which have been successfully used in the treatment of several types of cancer.Methods:We carried out a structured search among literature regarding to amino acid degrading enzymes. The main aspects of search were in vitro and in vivo studies, clinical trials concerning application of these enzymes in oncology.Results:Most published research are on the subject of L-asparaginase properties and it’s use for cancer treatment. L-arginine deiminase has shown promising results in a phase II trial in advanced melanoma and hepatocellular carcinoma. Other enzymes, in particular Lmethionine γ-lyase and L-lysine α-oxidase, were effective in vitro and in vivo.Conclusion:The findings of this review revealed that therapy based on amino acid depletion may have the potential application for cancer treatment but further clinical investigations are required to provide the efficacy and safety of these agents.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

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