scholarly journals The structural basis of the inhibition of human α-mannosidases by azafuranose analogues of mannose

1993 ◽  
Vol 290 (3) ◽  
pp. 743-749 ◽  
Author(s):  
B Winchester ◽  
S al Daher ◽  
N C Carpenter ◽  
I Cenci di Bello ◽  
S S Choi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Human Liver ◽  
Potent Inhibitor ◽  
Human Fibroblasts ◽  
Structural Basis ◽  
Multiple Forms ◽  
Storage Products ◽  
Normal Human ◽  
Ring Nitrogen

Eight pyrrolidine, five pyrrolizidine and one indolizidine analogue(s) of the known alpha-mannosidase inhibitor, the azafuranose, 1,4-dideoxy-1,4-imino-D-mannitol (DIM), have been tested for inhibition of the multiple forms of alpha-mannosidase in human liver in vitro. Substitution of the ring nitrogen markedly decreased or abolished inhibition, but loss of the C-6 hydroxy group, as in 6-deoxy-DIM and 6-deoxy-6-fluoro-DIM, enhanced inhibition, particularly of the lysosomal alpha-mannosidase. Addition of the anomeric substituent-CH2OH decreased inhibition. To be a potent inhibitor of the lysosomal, Golgi II and neutral alpha-mannosidases, a polyhydroxylated pyrrolidine must have the same substituents and chirality as mannofuranose at C-2, C-3, C-4 and C-5. These four chiral centres can also be part of a polyhydroxylated indolizidine, e.g. swainsonine, but not of a pyrrolizidine, e.g. cyclized DIM, ring-contracted swainsonine or 1,7-diepi-australine. DIM did not inhibit lysosomal alpha-mannosidase intracellularly, but both 6-deoxy-DIM and 6-deoxy-6-fluoro-DIM caused accumulation of partially catabolized glycans in normal human fibroblasts. Analysis of these induced storage products by h.p.l.c. showed that both compounds also inhibited Golgi alpha-mannosidase II and that 6-deoxy-6-fluoro-DIM was also a good inhibitor of the endoplasmic reticulum alpha-mannosidase and specific lysosomal alpha (1-6)-mannosidase. None of the mannofuranose analogues appeared to inhibit Golgi alpha-mannosidase I.

scholarly journals Scaffold Hopping of α-Rubromycin Enables Direct Access to FDA-Approved Cromoglicic Acid as a SARS-CoV-2 MPro Inhibitor

2021 ◽  
Vol 14 (6) ◽  
pp. 541
Author(s):  
Hani A. Alhadrami ◽  
Ahmed M. Sayed ◽  
Heba Al-Khatabi ◽  
Nabil A. Alhakamy ◽  
Mostafa E. Rateb
Keyword(s):  
Binding Free Energy ◽  
Human Fibroblasts ◽  
Critical Time ◽  
Dynamics Simulation ◽  
Direct Access ◽  
Energy Calculation ◽  
Wide Range ◽  
Normal Human ◽  
Novel Scaffold

The COVID-19 pandemic is still active around the globe despite the newly introduced vaccines. Hence, finding effective medications or repurposing available ones could offer great help during this serious situation. During our anti-COVID-19 investigation of microbial natural products (MNPs), we came across α-rubromycin, an antibiotic derived from Streptomyces collinus ATCC19743, which was able to suppress the catalytic activity (IC50 = 5.4 µM and Ki = 3.22 µM) of one of the viral key enzymes (i.e., MPro). However, it showed high cytotoxicity toward normal human fibroblasts (CC50 = 16.7 µM). To reduce the cytotoxicity of this microbial metabolite, we utilized a number of in silico tools (ensemble docking, molecular dynamics simulation, binding free energy calculation) to propose a novel scaffold having the main pharmacophoric features to inhibit MPro with better drug-like properties and reduced/minimal toxicity. Nevertheless, reaching this novel scaffold synthetically is a time-consuming process, particularly at this critical time. Instead, this scaffold was used as a template to explore similar molecules among the FDA-approved medications that share its main pharmacophoric features with the aid of pharmacophore-based virtual screening software. As a result, cromoglicic acid (aka cromolyn) was found to be the best hit, which, upon in vitro MPro testing, was 4.5 times more potent (IC50 = 1.1 µM and Ki = 0.68 µM) than α-rubromycin, with minimal cytotoxicity toward normal human fibroblasts (CC50 > 100 µM). This report highlights the potential of MNPs in providing unprecedented scaffolds with a wide range of therapeutic efficacy. It also revealed the importance of cheminformatics tools in speeding up the drug discovery process, which is extremely important in such a critical situation.

scholarly journals Design, Synthesis, and Cytotoxicity Assessment of [64Cu]Cu-NOTA-Terpyridine Platinum Conjugate: A Novel Chemoradiotherapeutic Agent with Flexible Linker

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2154
Author(s):  
Meysam Khosravifarsani ◽  
Samia Ait-Mohand ◽  
Benoit Paquette ◽  
Léon Sanche ◽  
Brigitte Guérin
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Human Fibroblasts ◽  
Fold Increase ◽  
Radiation Energy ◽  
Design Synthesis ◽  
Quadruplex Dna ◽  
Low Energy Electrons ◽  
Normal Human

Maximum benefits of chemoradiation therapy with platinum-based compounds are expected if the radiation and the drug are localized simultaneously in cancer cells. To optimize this concomitant effect, we developed the novel chemoradiotherapeutic agent [64Cu]Cu-NOTA-C3-TP by conjugating, via a short flexible alkyl chain spacer (C3), a terpyridine platinum (TP) moiety to a NOTA chelator complexed with copper-64 (64Cu). The decay of 64Cu produces numerous low-energy electrons, enabling the 64Cu-conjugate to deliver radiation energy close to TP, which intercalates into G-quadruplex DNA. Accordingly, the in vitro internalization kinetic and the cytotoxic activity of [64Cu]Cu-NOTA-C3-TP and its derivatives were investigated with colorectal cancer (HCT116) and normal human fibroblast (GM05757) cells. Radiolabeling by 64Cu results in a >55,000-fold increase of cytotoxic potential relative to [NatCu]Cu-NOTA-C3-TP at 72 h post administration, indicating a large additive effect between 64Cu and the TP drug. The internalization and nucleus accumulation of [64Cu]Cu-NOTA-C3-TP in the HCT116 cells were, respectively, 3.1 and 6.0 times higher than that for GM05757 normal human fibroblasts, which is supportive of the higher efficiency of the [64Cu]Cu-NOTA-C3-TP for HCT116 cancer cells. This work presents the first proof-of-concept study showing the potential use of the [64Cu]Cu-NOTA-C3-TP conjugate as a targeted chemoradiotherapeutic agent to treat colorectal cancer.

Chromosome 7 suppresses indefinite division of nontumorigenic immortalized human fibroblast cell lines KMST-6 and SUSM-1

1993 ◽  
Vol 13 (10) ◽  
pp. 6036-6043
Author(s):  
T Ogata ◽  
D Ayusawa ◽  
M Namba ◽  
E Takahashi ◽  
M Oshimura ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Cell ◽  
Human Fibroblasts ◽  
Fibroblast Cell ◽  
Chromosome 7 ◽  
In Vitro Mutagenesis ◽  
Human Cell Lines ◽  
First Case ◽  
Normal Human

Using nontumorigenic immortalized human cell lines KMST-6 (KMST) and SUSM-1 (SUSM), we attempted to identify the chromosome that carries a putative senescence-related gene(s). These cell lines are the only ones that have been established independently from normal human diploid fibroblasts following in vitro mutagenesis. We first examined restriction fragment length polymorphisms on each chromosome of these immortalized cell lines and their parental cell lines and found specific chromosomal alterations common to these cell lines (a loss of heterozygosity in KMST and a deletion in SUSM) on the long arm of chromosome 7. In addition to these, we also found that introduction of chromosome 7 into these cell lines by means of microcell fusion resulted in the cessation of cell division, giving rise to cells resembling cells in senescence. Introduction of other chromosomes, such as chromosomes 1 and 11, on which losses of heterozygosity were also detected in one of the cell lines (KMST), to either KMST or SUSM cells or of chromosome 7 to several tumor-derived cell lines had no effect on their division potential. These results strongly suggest that a gene(s) affecting limited-division potential or senescence of normal human fibroblasts is located on chromosome 7, probably at the long arm of the chromosome, representing the first case in which a specific chromosome reverses the immortal phenotype of otherwise normal human cell lines.

scholarly journals Serum from calorie-restricted animals delays senescence and extends the lifespan of normal human fibroblasts in vitro

Aging ◽  
2015 ◽  
Vol 7 (3) ◽  
pp. 152-166 ◽  
Author(s):  
Rafael de Cabo ◽  
Lijuan Liu ◽  
Ahmed Ali ◽  
Nathan Price ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Human Fibroblasts ◽  
Normal Human

Ru(III) complexes of pyrazolopyrimidines as anticancer agents: In vitro, in vivo anticancer activity and underlying multi-mechanisms

2022 ◽  
Author(s):  
Yunqiong Gu ◽  
Wen-Ying Shen ◽  
Qi-Yuan Yang ◽  
Zhen-Feng Chen ◽  
Hong Liang
Keyword(s):  
Anticancer Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Anticancer Agents ◽  
Human Liver ◽  
Normal Human Liver ◽  
Normal Human ◽  
Low Toxicity

Three ruthenium(III) complexes with pyrazolopyrimidine [Ru(Ln)(H2O)Cl3] (13, n=13) were prepared and characterized. These Ru(III) compounds show strong cytotoxicity against six cancer cell lines and low toxicity to normal human liver...

Transformation of Normal Human Fibroblasts into Histologically Malignant Tissue in vitro

Science ◽  
1956 ◽  
Vol 123 (3195) ◽  
pp. 502-503
Author(s):  
Joseph Leighton ◽  
Ira Kline ◽  
Henry C. Orr
Keyword(s):  
Human Fibroblasts ◽  
Malignant Tissue ◽  
Normal Human

scholarly journals The structural basis of the inhibition of human glycosidases by castanospermine analogues

1990 ◽  
Vol 269 (1) ◽  
pp. 227-231 ◽  
Author(s):  
B G Winchester ◽  
I Cenci di Bello ◽  
A C Richardson ◽  
R J Nash ◽  
L E Fellows ◽  
...  
Keyword(s):  
Structural Feature ◽  
Human Liver ◽  
Potent Inhibitor ◽  
Structural Basis ◽  
Preferential Recognition ◽  
Derivatives Of ◽  
Do So

A series of epimers and deoxy derivatives of castanospermine has been synthesized to investigate the contribution of the different chiral centres to the specificity and potency of inhibition of human liver glycosidases. Castanospermine inhibits all forms of alpha- and beta-D-glucosidases, but alteration to any of the five chiral centres in castanospermine markedly decreases the inhibition. 6-Epicastanospermine, which is related to D-pyranomannose in the same way as castanospermine is to D-pyranoglucose, does not inhibit lysosomal (acidic) alpha-mannosidase, but is a good inhibitor of the cytosolic or neutral alpha-mannosidase. Conversely, 1-deoxy-6-epicastanospermine inhibits acidic alpha-mannosidase strongly, but not the neutral alpha-mannosidase. An explanation of this different inhibition based on preferential recognition of different configurations of mannose by the different forms of alpha-mannosidase is postulated. All derivatives of 6-epicastanospermine also have the minimum structural feature for the inhibition of alpha-L-fucosidase, but those with a beta-anomeric substituent do not inhibit the enzyme, or do so very weakly. 1-Deoxy-6,8a-diepicastanospermine, which has four chiral centres identical with alpha-L-fucose, is, however, a potent inhibitor of alpha-L-fucosidase (Ki 1.3 microM).

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