scholarly journals Relationship between membrane sterol composition and responsiveness to 12-O-tetradecanoylphorbol 13-acetate in HL-60 human promyelocytic leukaemia cell lines

1988 ◽  
Vol 250 (2) ◽  
pp. 349-353 ◽  
Author(s):  
E Malvoisin ◽  
F Wild ◽  
G Zwingelstein

We have examined the sterol composition and metabolism of promyelocytic leukaemia cell lines (HL-60) after treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA). A variant cell line (Blast II cells) which is resistant to TPA was used as control. Analysis of the sterols of TPA-sensitive cells radiolabelled with [3H]leucine, [14C]acetate or [14C]pyruvate showed a high incorporation into cholesterol and a low incorporation in lanosterol + dihydrolanosterol. The inverse relationship was observed in TPA-resistant cells. Experiments with other cellular variants representing TPA-sensitive and TPA-resistant classes gave similar results. Analysis of the cellular sterol composition by gas chromatography confirmed that TPA-resistant cells are particularly rich in lanosterol/dihydrolanosterol. TPA treatment enhanced the incorporation of [14C]pyruvate into the sterol fraction of both cell types. This was accompanied by an alteration of incorporation into several lipids, particularly phospholipids. Pulse-chase studies with [14C]acetate revealed that TPA induced the release of radioactive lipids into the medium from HL-60 and Blast II cells. However this treatment released phospholipids from the TPA-sensitive cells and sterols and fatty acids from the TPA-resistant cells. We conclude that the sterol composition can regulate specific biochemical processes in the membrane and can be considered as a factor that plays a role in the responsiveness of HL-60 cells to TPA.

2021 ◽  
Vol 49 (1) ◽  
pp. 12233
Author(s):  
Ramy M. ROMEILAH ◽  
Hossam S. EL-BELTAGI ◽  
Emad A. SHALABY ◽  
Kareem M. YOUNES ◽  
Hani EL MOLL ◽  
...  

Essential (volatile) oil from leaves of Artemisia monosperma L. belonging to family Asteraceae, and aerial parts of Tamarix aphylla L. (Athel) belonging to family Tamaricaceae were collected from the desert of Ha'il region, northern region of Saudi Arabia, hydro distilled by Clevenger apparatus and analysed by means of GC-MS techniques. Antioxidant activities of essential oils of A. monosperma and T. aphylla compared with ascorbic acid and butylated hydroxytoluene (BHT) as reference antioxidant compound were determined by method of DPPH radical scavenging assay and ABTS assay. In vitro screening of potential cytotoxicity of essential oils was also evaluated against human promyelocytic leukaemia cell lines (HL60 and NB4). The GC/MS analysis of A. monosperma essential oil resulted in identification of 61 components predominated mainly by β-Pinene as principal component (29.87%) and T. aphylla resulted in identification of 37 components of essential oil predominated mainly by 6,10,14- trimethyl-2-pentadecanone (21.43%) as principal component. Antioxidant activity as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 2,2 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) increased with increasing essential oil concentrations of A. monosperma and T. aphylla (25, 50, 75, 100 and 200 μg mL-1). The most pronounced increases detected in the high concentrations of the two essential oils. Biologically, essential oil extracts exhibited cytotoxicity effects in dose dependent manner against human promyelocytic leukaemia cell lines (HL60 and NB4). In conclusion, A. monosperma and T. aphylla essential oils could be valuable source for cytotoxic agents with high safety and selective cytotoxicity profiles.


2021 ◽  
Vol 22 (13) ◽  
pp. 7114
Author(s):  
Ahmad Zulkifli ◽  
Fiona H. Tan ◽  
Zammam Areeb ◽  
Sarah F. Stuart ◽  
Juliana Gomez ◽  
...  

Cetuximab is a common treatment option for patients with wild-type K-Ras colorectal carcinoma. However, patients often display intrinsic resistance or acquire resistance to cetuximab following treatment. Here we generate two human CRC cells with acquired resistance to cetuximab that are derived from cetuximab-sensitive parental cell lines. These cetuximab-resistant cells display greater in vitro proliferation, colony formation and migration, and in vivo tumour growth compared with their parental counterparts. To evaluate potential alternative therapeutics to cetuximab-acquired-resistant cells, we tested the efficacy of 38 current FDA-approved agents against our cetuximab-acquired-resistant clones. We identified carfilzomib, a selective proteosome inhibitor to be most effective against our cell lines. Carfilzomib displayed potent antiproliferative effects, induced the unfolded protein response as determined by enhanced CHOP expression and ATF6 activity, and enhanced apoptosis as determined by enhanced caspase-3/7 activity. Overall, our results indicate a potentially novel indication for carfilzomib: that of a potential alternative agent to treat cetuximab-resistant colorectal cancer.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 953
Author(s):  
Chuan Xu ◽  
Annie Wang ◽  
Ke Geng ◽  
William Honnen ◽  
Xuening Wang ◽  
...  

Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2), the causative agent of coronavirus disease 19 (COVID-19), enters cells through attachment to the human angiotensin converting enzyme 2 (hACE2) via the receptor-binding domain (RBD) in the surface/spike (S) protein. Several pseudotyped viruses expressing SARS-CoV-2 S proteins are available, but many of these can only infect hACE2-overexpressing cell lines. Here, we report the use of a simple, two-plasmid, pseudotyped virus system comprising a SARS-CoV-2 spike-expressing plasmid and an HIV vector with or without vpr to investigate the SARS-CoV-2 entry event in various cell lines. When an HIV vector without vpr was used, pseudotyped SARS-CoV-2 viruses produced in the presence of fetal bovine serum (FBS) were able to infect only engineered hACE2-overexpressing cell lines, whereas viruses produced under serum-free conditions were able to infect a broader range of cells, including cells without hACE2 overexpression. When an HIV vector containing vpr was used, pseudotyped viruses were able to infect a broad spectrum of cell types regardless of whether viruses were produced in the presence or absence of FBS. Infection sensitivities of various cell types did not correlate with mRNA abundance of hACE2, TMPRSS2, or TMPRSS4. Pseudotyped SARS-CoV-2 viruses and replication-competent SARS-CoV-2 virus were equally sensitive to neutralization by an anti-spike RBD antibody in cells with high abundance of hACE2. However, the anti-spike RBD antibody did not block pseudotyped viral entry into cell lines with low abundance of hACE2. We further found that CD147 was involved in viral entry in A549 cells with low abundance of hACE2. Thus, our assay is useful for drug and antibody screening as well as for investigating cellular receptors, including hACE2, CD147, and tyrosine-protein kinase receptor UFO (AXL), for the SARS-CoV-2 entry event in various cell lines.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lourdes G. Talavera-Aguilar ◽  
Reyes A. Murrieta ◽  
Sungmin Kiem ◽  
Rosa C. Cetina-Trejo ◽  
Carlos M. Baak-Baak ◽  
...  

Abstract Background Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) with an urban transmission cycle that primarily involves humans and Aedes aegypti. Evidence suggests that the evolution of some arboviruses is constrained by their dependency on alternating between disparate (vertebrate and invertebrate) hosts. The goals of this study are to compare the genetic changes that occur in ZIKV after serial passaging in mosquito or vertebrate cell lines or alternate passaging in both cell types and to compare the replication, dissemination, and transmission efficiencies of the cell culture-derived viruses in Ae. aegypti. Methods An isolate of ZIKV originally acquired from a febrile patient in Yucatan, Mexico, was serially passaged six times in African green monkey kidney (Vero) cells or Aedes albopictus (C6/36) cells or both cell types by alternating passage. A colony of Ae. aegypti from Yucatan was established, and mosquitoes were challenged with the cell-adapted viruses. Midguts, Malpighian tubules, ovaries, salivary glands, wings/legs and saliva were collected at various times after challenge and tested for evidence of virus infection. Results Genome sequencing revealed the presence of two non-synonymous substitutions in the premembrane and NS1 regions of the mosquito cell-adapted virus and two non-synonymous substitutions in the capsid and NS2A regions of both the vertebrate cell-adapted and alternate-passaged viruses. Additional genetic changes were identified by intrahost variant frequency analysis. Virus maintained by continuous C6/36 cell passage was significantly more infectious in Ae. aegypti than viruses maintained by alternating passage and consecutive Vero cell passage. Conclusions Mosquito cell-adapted ZIKV displayed greater in vivo fitness in Ae. aegypti compared to the other viruses, indicating that obligate cycling between disparate hosts carries a fitness cost. These data increase our understanding of the factors that drive ZIKV adaptation and evolution and underscore the important need to consider the in vivo passage histories of flaviviruses to be evaluated in vector competence studies. Graphic abstract "Image missing"


1986 ◽  
Vol 103 (6) ◽  
pp. 2411-2420 ◽  
Author(s):  
E F Plow ◽  
D E Freaney ◽  
J Plescia ◽  
L A Miles

The capacity of cells to interact with the plasminogen activator, urokinase, and the zymogen, plasminogen, was assessed using the promyeloid leukemic U937 cell line and the diploid fetal lung GM1380 fibroblast cell line. Urokinase bound to both cell lines in a time-dependent, specific, and saturable manner (Kd = 0.8-2.0 nM). An active catalytic site was not required for urokinase binding to the cells, and 55,000-mol-wt urokinase was selectively recognized. Plasminogen also bound to the two cell lines in a specific and saturable manner. This interaction occurred with a Kd of 0.8-0.9 microM and was of very high capacity (1.6-3.1 X 10(7) molecules bound/cell). The interaction of plasminogen with both cell types was partially sensitive to trypsinization of the cells and required an unoccupied high affinity lysine-binding site in the ligand. When plasminogen was added to the GM1380 cells, a line with high intrinsic plasminogen activator activity, the bound ligand was comprised of both plasminogen and plasmin. Urokinase, in catalytically active or inactive form, enhanced plasminogen binding to the two cell lines by 1.4-3.3-fold. Plasmin was the predominant form of the bound ligand when active urokinase was added, and preformed plasmin can also bind directly to the cells. Plasmin on the cell surface was also protected from its primary inhibitor, alpha 2-antiplasmin. These results indicate that the two cell lines possess specific binding sites for plasminogen and urokinase, and a family of widely distributed cellular receptors for these components may be considered. Endogenous or exogenous plasminogen activators can generate plasmin on cell surfaces, and such activation may provide a mechanism for arming cell surfaces with the broad proteolytic activity of this enzyme.


2014 ◽  
Vol 3 (5) ◽  
pp. 1099-1111 ◽  
Author(s):  
Blanca D. Lopez‐Ayllon ◽  
Veronica Moncho‐Amor ◽  
Ander Abarrategi ◽  
Inmaculada Ibañez Cáceres ◽  
Javier Castro‐Carpeño ◽  
...  

2001 ◽  
Vol 75 (17) ◽  
pp. 7944-7955 ◽  
Author(s):  
Noriko Nakajima ◽  
Richard Lu ◽  
Alan Engelman

ABSTRACT Functional retroviral integrase protein is thought to be essential for productive viral replication. Yet, previous studies differed on the extent to which integrase mutant viruses expressed human immunodeficiency virus type 1 (HIV-1) genes from unintegrated DNA. Although one reason for this difference was that class II integrase mutations pleiotropically affected the viral life cycle, another reason apparently depended on the identity of the infected cell. Here, we analyzed integrase mutant viral infectivities in a variety of cell types. Single-round infectivity of class I integration-specific mutant HIV-1 ranged from <0.03 to 0.3% of that of the wild type (WT) across four different T-cell lines. Based on this approximately 10-fold influence of cell type on mutant gene expression, we examined class I and class II mutant replication kinetics in seven different cell lines and two primary cell types. Unexpectedly, some cell lines supported productive class I mutant viral replication under conditions that restricted class II mutant growth. Cells were defined as permissive, semipermissive, or nonpermissive based on their ability to support the continual passage of class I integration-defective HIV-1. Mutant infectivity in semipermissive and permissive cells as quantified by 50% tissue culture infectious doses, however, was only 0.0006 to 0.005% of that of WT. Since the frequencies of mutant DNA recombination in these lines ranged from 0.023 to <0.093% of the WT, we conclude that productive replication in the absence of integrase function most likely required the illegitimate integration of HIV-1 into host chromosomes by cellular DNA recombination enzymes.


2012 ◽  
Vol 53 ◽  
pp. S158-S159
Author(s):  
F. Vieceli Dalla Sega⁎ ◽  
L. Zambonin ◽  
D. Fiorentini ◽  
B. Rizzo ◽  
L. Landi ◽  
...  

1993 ◽  
Vol 291 (1) ◽  
pp. 131-137 ◽  
Author(s):  
L Albanese ◽  
R J Bergeron ◽  
A E Pegg

N1N12-Bis(ethyl)spermine (BESM) and related compounds are powerful inhibitors of cell growth that may have potential as anti-neoplastic agents [Bergeron, Neims, McManis, Hawthorne, Vinson, Bortell and Ingeno (1988) J. Med. Chem. 31, 1183-1190]. The mechanism by which these compounds bring about their effects was investigated by using variant cell lines in which processes thought to be altered by these agents are perturbed. Comparisons between the response of these cells and of their parental equivalents to BESM, N1N11-bis(ethyl)norspermine, N1N14-bis(ethyl)homospermine and N1N8-bis(ethyl)spermidine were then made. It was found that D-R cells, an L1210-derived line that over-expresses ornithine decarboxylase, were not resistant to these compounds. This indicates that the decrease in ornithine decarboxylase is not critical for the action of the compounds on cell growth. Furthermore, although polyamine levels were decreased in the D-R cells, the content was not totally depleted, indicating that such depletion is also not essential for the anti-proliferative effect. Two cell lines lacking mitochondrial DNA (human 143B206 cells and chicken DU3 cells) did not differ in sensitivity to BESM from their parental 143BTK- and DU24 cells. Furthermore, the inhibition of respiration in L1210 cells in response to BESM developed more slowly than the inhibition of growth. Thus it appears that the inhibitions of mitochondrial DNA synthesis and of mitochondrial respiration are also not primary factors in the anti-proliferative effects of these polyamine analogues. The inhibition of growth did, however, correlate with the intracellular accumulation of the analogues. It appears that the bis(ethyl)polyamine derivatives act by binding to intracellular target molecules and preventing macromolecular synthesis. The decline in normal polyamines may facilitate such binding, but is not essential for growth arrest.


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