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Volume10, Issue 12 (Suppl) J Proteomics Bioinform, an open access journal
ISSN: 0974-276X
Page 83
conferenceseries.com
World Biomarkers & Pharma Biotech 2017
December 07-09, 2017
December 07-09, 2017 | Madrid, Spain
&
20th International Conference on
PHARMACEUTICAL BIOTECHNOLOGY
9th WORLD BIOMARKERS CONGRESS
JOINT EVENT ON
Investigation of expression levels of DNA repair genes in molecular subtypes of breast cancer
Ece Salihoglu1, Semra Demokan 2, Hasan Karanlik2, Bensu Karahalil1, Semen Önder2 and Sevgiyardim Akaydin1
1Gazi University School of Pharmacy, Turkey
2Institute of Oncology, Istanbul University, Turkey
Tip60 histone acetyltransferase (HAT) is critical importance for activation of DNA repair as well as plays role in chromatin
remodeling and histone acetylation. After DNA damage, Tip60 acetyltransferase rapidly acetylates and activates ataxia-
telangiectasia mutated (ATM) kinase which activates other proteins, such as p53, Chk2, BRCA1, H2AX etc., involved cell-cycle
checkpoints and DNA repair. This mechanismmay affect radiotherapy sensitivities of the cancer patients. The aim of this study
is was to evaluate the status of Tip60-ATM complex in molecular subtypes (Luminal A and B, Her2+, and Triple-) of breast
cancer. For this purpose, firstly, mRNA expression levels of Tip60, ATM, p53, BRCA1, Chk2 and H2AX measured by qRT-PCR
in normal and tumor tissues of breast cancer patients and normal tissues of healthy individuals. When we compared mRNA
expressions in normal tissues of total patients with healthy controls, we did not find statistically significant differences (p>0.05).
In the total patient group, Tip60, ATM, and BRCA1 expressions decreased (p=0.08, p=0.01, and p=0.017, respectively) and
p53, Chk2 increased (p=0.048 and p=0.130, respectively) in tumor tissues than those in normal tissues in the same patients.
According to the subtypes, 47% of Lum A patients, 16.7% of Lum B patients, 56.3% of Triple- patients and 27.3% of Her2+
patients had shown higher Tip60 mRNA expression levels in tumor tissues than in their normal tissues. Similar results were
obtained for the other genes and statistically significant differences were observed in normal tissue expressions of almost all
genes between Lum B with Lum A and Triple (-) groups. Also, there are significantly positive correlations among genes in the
total group, and subtypes, especially in Lum A and Lum B groups. In conclusion, results obtained in this study suggest that
patients with higher gene expression ratios in tumor tissues than in normal tissues may have lower radio therapy sensitivities
due to the role of Tip60 complex in the repair of DNA damage. Inhibition of Tip60 could be used as a novel radiosensitizing
target for breast cancer patients.
Biography
Ece Salihoğlu attended primary, secondary and high school in Ankara. She graduated from the Department of Biology Education of Hacettepe University in 2007.
She earned her Master’s Degree in Biochemistry from Gazi University, Faculty of Pharmacy in 2011. Then she started her PhD program at the same department
and will finish on January. She is currently working on DNA repair mechanism in breast cancer.
Ece Salihoglu et al., J Proteomics Bioinform 2017, 10:12(Suppl)
DOI: 10.4172/0974-276X-C1-110