A link between aberrant methylation level and AA adducts: Fact or | 54200
Journal of Chromatography & Separation Techniques

Journal of Chromatography & Separation Techniques
Open Access

ISSN: 2157-7064

+44 1300 500008

A link between aberrant methylation level and AA adducts: Fact or coincidence

World Congress on Chromatography

September 21-23, 2016 Amsterdam, Netherlands

Dalia El-Zeihery, Mohamed Abd El Kawy, Oliver Schmitz, Cai Zongwei and Heinz Schmeiser

Beni-Suef University, Egypt
Essen-Duisburg University, Germany
Hong Kong Baptist University, China
German Cancer Research Center, Germany

Posters & Accepted Abstracts: J Chromatogr Sep Tech

Abstract :

The main aim of this study is to estimate the effect of aristolochic acid (AA) on the genomic methylation level (5-methylcytosine, 5mc) of Sprague-Dawley rats subjected to a single oral dose of 30 mg AA/kg over three weeks-period, and to detect AADNA adducts in tissues of rodents. Our analytical method involves hydrolyzing the DNA extracted from different organs to 2-deoxyribose-3â�?�?-phosphate, labeling the nucleotides with a fluorescence marker, then measuring the genome wide methylation level with micellar electrokinetic chromatography using laser-induced fluorescence detector (MEKC-LIF). The results had shown different behavior patterns in the methylation level according to the tested organ. An obvious hypermethylation was observed in kidney, stomach and colon of rats dosed with AA, in comparison with their respective controls. Individual 5mc levels are (3.97�?±0.05, 3.90�?±0.04 and 4.46�?±0.04%) for organs, respectively. Bladder, small intestine and liver did not exhibit either hyper- or hypo- methylation. We further studied the samples for detection of AA-adducts in two complementary studies. The deoxyadenosine-AA-adducts were identified in kidney (Adduct level, 2.63 to 5.16/106 nucleotides) and colon tissues (0.28 to 1.01/106 nucleotides) among several tissues analyzed by the 32P-postlabeling method. While control samples were free from DNA adducts spots. As well, the highest AA-DNA adduct concentration was detected in kidneys of the AA-dosed rats by LC-ESI-MS method. Our study highlights the relation between the exposure to this carcinogen belonging to natural product group (AA) and the aberration of methylation level that contributes to understanding the involvement of AA-adducts in cancer development via epigenetic modification.

Biography :

Dalia Mohamed El-Zeihery received her PhD from the Bergische Universitaet Wuppertal in Germany and completed Post-doctoral studies at CRO in Germany. She is lecturer of Analytical Chemistry at Beni Suef University in Egypt. She has strong footing in teaching and research, in depth theoretical knowledge and hands-on experience in analytical techniques: like capillary electrophoresis, HPLC-MS and UV-VIS spectroscopy. She was awarded third prize of Pharmaceutical and Bio-analysis from Pfizer for her poster at the 2009 34th International Symposium on HPLC Separations and Related Techniques. His research interests are development and validation of bio-analytical methods for analysis of drugs, proteins and biomarkers.