scholarly journals Optimization of the comet assay for the sensitive detection of PUVA-induced DNA interstrand cross-links

Mutagenesis ◽  
2008 ◽  
Vol 24 (2) ◽  
pp. 173-181 ◽  
Author(s):  
J. H. Wu ◽  
J. B. Wilson ◽  
A. M. Wolfreys ◽  
A. Scott ◽  
N. J. Jones
Keyword(s):  
Comet Assay ◽  
Sensitive Detection ◽  
Interstrand Cross Links ◽  
Cross Links

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

scholarly journals Validation of the in vitro comet assay for DNA cross-links and altered bases detection

2021 ◽  
Author(s):  
Damián Muruzabal ◽  
Julen Sanz-Serrano ◽  
Sylvie Sauvaigo ◽  
Bertrand Treillard ◽  
Ann-Karin Olsen ◽  
...  
Keyword(s):  
Comet Assay ◽  
Human Health Risk ◽  
High Sensitivity ◽  
Dna Lesions ◽  
Dna Glycosylase ◽  
Vitro Assay ◽  
Cytotoxic Compound ◽  
Endonuclease Iii ◽  
Cross Links

AbstractMechanistic toxicology is gaining weight for human health risk assessment. Different mechanistic assays are available, such as the comet assay, which detects DNA damage at the level of individual cells. However, the conventional alkaline version only detects strand breaks and alkali-labile sites. We have validated two modifications of the in vitro assay to generate mechanistic information: (1) use of DNA-repair enzymes (i.e., formamidopyrimidine DNA glycosylase, endonuclease III, human 8-oxoguanine DNA glycosylase I and human alkyladenine DNA glycosylase) for detection of oxidized and alkylated bases as well as (2) a modification for detecting cross-links. Seven genotoxicants with different mechanisms of action (potassium bromate, methyl methanesulfonate, ethyl methanesulfonate, hydrogen peroxide, cisplatin, mitomycin C, and benzo[a]pyrene diol epoxide), as well as a non-genotoxic compound (dimethyl sulfoxide) and a cytotoxic compound (Triton X-100) were tested on TK-6 cells. We were able to detect with high sensitivity and clearly differentiate oxidizing, alkylating and cross-linking agents. These modifications of the comet assay significantly increase its sensitivity and its specificity towards DNA lesions, providing mechanistic information regarding the type of damage.

Increased gene-specific repair of cisplatin interstrand cross-links in cisplatin-resistant human ovarian cancer cell lines

1992 ◽  
Vol 12 (9) ◽  
pp. 3689-3698
Author(s):  
W Zhen ◽  
C J Link ◽  
P M O'Connor ◽  
E Reed ◽  
R Parker ◽  
...  
Keyword(s):  
Cell Lines ◽  
Ovarian Cancer Cell ◽  
Parental Cell ◽  
Resistant Cell ◽  
Dhfr Gene ◽  
Human Ovarian Cancer Cell ◽  
Ovarian Cancer Cell Lines ◽  
Repair Efficiency ◽  
Interstrand Cross Links ◽  
Cross Links

We have studied several aspects of DNA damage formation and repair in human ovarian cancer cell lines which have become resistant to cisplatin through continued exposure to the anticancer drug. The resistant cell lines A2780/cp70 and 2008/c13*5.25 were compared with their respective parental cell lines, A2780 and 2008. Cells in culture were treated with cisplatin, and the two main DNA lesions formed, intrastrand adducts and interstrand cross-links, were quantitated before and after repair incubation. This quantitation was done for total genomic lesions and at the level of individual genes. In the overall genome, the initial frequency of both cisplatin lesions assayed was higher in the parental than in the derivative resistant cell lines. Nonetheless, the total genomic repair of each of these lesions was not increased in the resistant cells. These differences in initial lesion frequency between parental and resistant cell lines were not observed at the gene level. Resistant and parental cells had similar initial frequencies of intrastrand adducts and interstrand cross-links in the dihydrofolate reductase (DHFR) gene and in several other genes after cisplatin treatment of the cells. There was no increase in the repair efficiency of intrastrand adducts in the DHFR gene in resistant cell lines compared with the parental partners. However, a marked and consistent repair difference between parental and resistant cells was observed for the gene-specific repair of cisplatin interstrand cross-links. DNA interstrand cross-links were removed from three genes, the DHFR, multidrug resistance (MDR1), and delta-globin genes, much more efficiently in the resistant cell lines than in the parental cell lines. Our findings suggest that acquired cellular resistance to cisplatin may be associated with increased gene-specific DNA repair efficiency of a specific lesion, the interstrand cross-link.

scholarly journals The Pso4 mRNA Splicing and DNA Repair Complex Interacts with WRN for Processing of DNA Interstrand Cross-links

2005 ◽  
Vol 280 (49) ◽  
pp. 40559-40567 ◽  
Author(s):  
Nianxiang Zhang ◽  
Ramandeep Kaur ◽  
Xiaoyan Lu ◽  
Xi Shen ◽  
Lei Li ◽  
...  
Keyword(s):  
Dna Repair ◽  
Mrna Splicing ◽  
Interstrand Cross Links ◽  
Cross Links

scholarly journals 4-vinyl-substituted pyrimidine nucleosides exhibit the efficient and selective formation of interstrand cross-links with RNA and duplex DNA

2013 ◽  
Vol 41 (13) ◽  
pp. 6774-6781 ◽  
Author(s):  
Atsushi Nishimoto ◽  
Daichi Jitsuzaki ◽  
Kazumitsu Onizuka ◽  
Yosuke Taniguchi ◽  
Fumi Nagatsugi ◽  
...  
Keyword(s):  
Duplex Dna ◽  
Pyrimidine Nucleosides ◽  
Interstrand Cross Links ◽  
Cross Links ◽  
Selective Formation
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