Hamadneh Lama, Al-Majawleh May, Jarrar Yazun, Shraim Sawsan, Hasan Mariam, Abu-Irmaileh Basha'er
Faculty of Pharmacy, Al-Zaytoonah University of Jordan, P.O. Box 130, Amman, 11733, Jordan.
Hamdi Mango Center for Scientific Research, University of Jordan, Amman, 11942, Jordan.
In Vitro Cell Dev Biol Anim. 2018 May;54(5):331-334. doi: 10.1007/s11626-018-0245-7. Epub 2018 Apr 9.
The levels of DNA methylation and their role in gene expression are key factors that could affect diagnosis, prognosis, and treatment options of different diseases. In this study, the methylation levels of 22 genes that are mostly correlated to breast cancer were determined using EpiTect methyl II PCR array. This analysis was performed to determine the effect of cells' passage number and the use of antibiotics in the culturing media on gene methylation levels in MCF7 cell line. DNA methylation levels of PTGS2, ADAM23, HIC1, and PYCARD were found to be significantly different among different passages. While the DNA methylation levels of CCNA1, RASSF1, and THBS1 were found to be affected by the use of 1% of penicillin/streptomycin in the culture media. Gene expression analysis after demethylation using 5-Aza-2'-deoxycytidine showed that the gene expression levels of the hypermethylated genes varied between different passage numbers. This study shows that the presence of antibiotic within cultured media and cell line's passage number could greatly affect the methylation levels that need to be considered in future studies on cell lines.
DNA甲基化水平及其在基因表达中的作用是影响不同疾病诊断、预后和治疗方案的关键因素。在本研究中，使用EpiTect甲基化II PCR芯片测定了22个与乳腺癌高度相关基因的甲基化水平。进行该分析以确定细胞传代次数以及培养基中抗生素的使用对MCF7细胞系基因甲基化水平的影响。发现PTGS2、ADAM23、HIC1和PYCARD的DNA甲基化水平在不同传代之间存在显著差异。而CCNA1、RASSF1和THBS1的DNA甲基化水平受培养基中1%青霉素/链霉素使用的影响。使用5-氮杂-2'-脱氧胞苷去甲基化后的基因表达分析表明，高甲基化基因的基因表达水平在不同传代次数之间有所不同。本研究表明，培养基中抗生素的存在以及细胞系的传代次数可能会极大地影响甲基化水平，这在未来关于细胞系的研究中需要加以考虑。
