scholarly journals Cell polarization is required for ricin sensitivity in a Caco-2 cell line selected for ricin resistance

1999 ◽  
Vol 341 (2) ◽  
pp. 323-327 ◽  
Author(s):  
Mark R. JACKMAN ◽  
Juliet A. ELLIS ◽  
Sally R. GRAY ◽  
Wenda SHURETY ◽  
J. Paul LUZIO
Keyword(s):  
Plasma Membrane ◽  
Cell Line ◽  
Mammalian Cells ◽  
Cell Clone ◽  
Membrane Traffic ◽  
Retrograde Transport ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Cell Polarization ◽  
Apical Plasma Membrane

It has been proposed that killing of mammalian cells by ricin requires efficient endocytic delivery to the trans-Golgi network (TGN) prior to retrograde transport to the endoplasmic reticulum and entry to the cytosol. In polarized epithelial cells, an efficient membrane-traffic pathway to the TGN is present from the basolateral but not the apical plasma-membrane domain. Thus one can hypothesize that a ricin-resistant phenotype might be demonstrated by polarized cells that fail to differentiate and thus fail to develop an efficient membrane-traffic pathway from the basolateral plasma membrane to the TGN. We have isolated and studied a ricin-resistant Caco-2 cell clone (Caco-2-RCAr clone 2) which, when grown on plastic, was deficient in differentiation, measured by the development of polarized-cell-surface marker enzymes. The deficiency in differentiation was partially reversed, and ricin sensitivity was restored, when the cells were grown on filter supports. Our data provide the first evidence of a ricin-resistant cell line where resistance is due to the lack of development of polarized cell surfaces. The observed ricin resistance is consistent with the requirement that ricin is delivered to the TGN before its A chain enters the cytosol to mediate cell killing.

scholarly journals Genomic Adaption and Mutational Patterns in a HaCaT Subline Resistant to Alkylating Agents and Ionizing Radiation

2021 ◽  
Vol 22 (3) ◽  
pp. 1146
Author(s):  
Reinhard Ullmann ◽  
Benjamin Valentin Becker ◽  
Simone Rothmiller ◽  
Annette Schmidt ◽  
Horst Thiermann ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Line ◽  
Copy Number ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Chromosomal Translocations ◽  
Dna Copy Number ◽  
Mutational Signatures ◽  
Copy Number Changes ◽  
And Oxidative Stress

Sulfur mustard (SM) is a chemical warfare agent that can damage DNA via alkylation and oxidative stress. Because of its genotoxicity, SM is cancerogenic and the progenitor of many chemotherapeutics. Previously, we developed an SM-resistant cell line via chronic exposure of the popular keratinocyte cell line HaCaT to increasing doses of SM over a period of 40 months. In this study, we compared the genomic landscape of the SM-resistant cell line HaCaT/SM to its sensitive parental line HaCaT in order to gain insights into genetic changes associated with continuous alkylation and oxidative stress. We established chromosome numbers by cytogenetics, analyzed DNA copy number changes by means of array Comparative Genomic Hybridization (array CGH), employed the genome-wide chromosome conformation capture technique Hi-C to detect chromosomal translocations, and derived mutational signatures by whole-genome sequencing. We observed that chronic SM exposure eliminated the initially prevailing hypotetraploid cell population in favor of a hyperdiploid one, which contrasts with previous observations that link polyploidization to increased tolerance and adaptability toward genotoxic stress. Furthermore, we observed an accumulation of chromosomal translocations, frequently flanked by DNA copy number changes, which indicates a high rate of DNA double-strand breaks and their misrepair. HaCaT/SM-specific single-nucleotide variants showed enrichment of C > A and T > A transversions and a lower rate of deaminated cytosines in the CpG dinucleotide context. Given the frequent use of HaCaT in toxicology, this study provides a valuable data source with respect to the original genotype of HaCaT and the mutational signatures associated with chronic alkylation and oxidative stress.

Platinum pyridinecarboxaldimine complexes containing boronate esters

2004 ◽  
Vol 82 (12) ◽  
pp. 1692-1699 ◽  
Author(s):  
Hanni A Darwish ◽  
Stephen J Scales ◽  
Jennifer L Horton ◽  
Liliya G Nikolcheva ◽  
Haiwen Zhang ◽  
...  
Keyword(s):  
Ovarian Carcinoma ◽  
Key Words ◽  
Cell Line ◽  
Platinum Complexes ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Boronate Esters ◽  
Human Ovarian Carcinoma

Condensation of 2-pyridinecarboxaldehydes with 2-, 3-, and 4-H2NC6H4Bpin (pin = 1,2-O2C2Me4) gave the corresponding boron-containing pyridinecarboxaldimines (N–NBpin). Addition of these ligands to [PtCl2(coe)]2 (coe = cis-cyclooctene) gave complexes of the type cis-PtCl2(N–NBpin) in moderate yields. The platinum complexes have been examined for their potential cytotoxicities against OV2008 (human ovarian carcinoma) and the analogous cisplatin-resistant cell line C13. Key words: boronate esters, pyridinecarboxaldimines, cytotoxicity, platinum, boron.

An immortalized drug-resistant cell line established from 12–13-day mouse embryos for the propagation of human embryonic stem cells

2006 ◽  
Vol 74 (4) ◽  
pp. 160-166 ◽  
Author(s):  
Shiro Iuchi ◽  
Meytha Marsch-Moreno ◽  
Cristina Velez-DelValle ◽  
Karen Easley ◽  
Walid Kuri-Harcuch ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Cell Line ◽  
Human Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Mouse Embryos ◽  
Drug Resistant ◽  
Drug Resistant Cell

scholarly journals Genotoxic Effects of Green Tea Extract on Human Laryngeal Carcinoma Cells In Vitro

2011 ◽  
Vol 62 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Ksenija Durgo ◽  
Sandra Kostić ◽  
Katarina Gradiški ◽  
Draženka Komes ◽  
Maja Osmak ◽  
...  
Keyword(s):  
Cell Line ◽  
Green Tea ◽  
Laryngeal Carcinoma ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Green Tea Extract ◽  
Carcinoma Cells ◽  
Tea Extract ◽  
Human Laryngeal Carcinoma

Genotoxic Effects of Green Tea Extract on Human Laryngeal Carcinoma Cells In VitroGreen tea (Camellia sinensis) contains several bioactive compounds which protect the cell and prevent tumour development. Phytochemicals in green tea extract (mostly flavonoids) scavenge free radicals, but also induce pro-oxidative reactions in the cell. In this study, we evaluated the potential cytotoxic and prooxidative effects of green tea extract and its two main flavonoid constituents epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) on human laryngeal carcinoma cell line (HEp2) and its cross-resistant cell line CK2. The aim was to see if the extract and its two flavonoids could increase the sensitivity of the cisplatin-resistant cell line CK2 in comparison to the parental cell line. The results show that EGCG and green tea extract increased the DNA damage in the CK2 cell line during short exposure. The cytotoxicity of EGCG and ECG increased with the time of incubation. Green tea extract induced lipid peroxidation in the CK2 cell line. The pro-oxidant effect of green tea was determined at concentrations higher than those found in traditionally prepared green tea infusions.

Efficacy of Chemotherapeutic Agents Under Hypoxic Conditions in Pulmonary Adenocarcinoma Multidrug Resistant Cell Line

2007 ◽  
Vol 19 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Shicang Yu ◽  
Guijun Huang ◽  
Guisheng Qian ◽  
Yuying Li ◽  
Guoming Wu ◽  
...  
Keyword(s):  
Cell Line ◽  
Multidrug Resistant ◽  
Resistant Cell ◽  
Chemotherapeutic Agents ◽  
Resistant Cell Line ◽  
Pulmonary Adenocarcinoma ◽  
Hypoxic Conditions

Epigenetic approaches to cancer therapy

2004 ◽  
Vol 32 (6) ◽  
pp. 1095-1097 ◽  
Author(s):  
J.A. Plumb ◽  
N. Steele ◽  
P.W. Finn ◽  
R. Brown
Keyword(s):  
Dna Methylation ◽  
Cell Line ◽  
Gene Promoter ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Tumour Suppressor Genes ◽  
Control Of Gene Expression ◽  
Hmlh1 Gene

Histone deacetylation and DNA methylation have a central role in the control of gene expression, including transcriptional repression of tumour suppressor genes. Loss of DNA mismatch repair due to methylation of the hMLH1 gene promoter results in resistance to cisplatin in vitro and in vivo. The cisplatin-resistant cell line A2780/cp70 is 8-fold more resistant to cisplatin than the non-resistant cell line, and has the hMLH1 gene methylated. Treatment with an inhibitor of DNA methyltransferase, DAC (2-deoxy-5′-azacytidine), results in a partial reversal of DNA methylation, re-expression of MLH1 (mutL homologue 1) and sensitization to cisplatin both in vitro and in vivo. PXD101 is a novel hydroxamate type histone deacetylase inhibitor that shows antitumour activity in vivo and is currently in phase I clinical evaluation. Treatment of A2780/cp70 tumour-bearing mice with DAC followed by PXD101 results in a marked increase in the number of cells that re-express MLH1. Since the clinical use of DAC may be limited by toxicity and eventual re-methylation of genes, we suggest that the combination of DAC and PXD101 could have a role in increasing the efficacy of chemotherapy in patients with tumours that lack MLH1 expression due to hMLH1 gene promoter methylation.

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