_1630698759 1630698759 brea akaviani@archbreastcancer.com Farname Inc Archives of Breast Cancer Arch Breast Cancer 2383-0433 04 15 2021 Zahra Mohammadi Abgarmi Abbas Sahebghadam Lotfi Saeid Abroun Masoud Soleimani Shahla Mohammad Ganji https://orcid.org/0000-0003-2032-8209 Parvaneh Baktash Arash Moradi https://orcid.org/0000-0002-1038-084X Background: The reactive oxygen species (ROS) generated in the biological systems play an important role in pathological conditions and specific normal cellular processes, such as signaling pathways and drug sensitivity. Methods: Intracellular ROS was determined using (2'-7'dichlorofluorescin diacetate) DCFH-DA fluorimetric probe, malondialdehyde as lipid peroxidation index detected by the Thiobarbituric acid reactive substances method. Cells' protein carbonyl contents were assessed with 2,4-Dinitrophenylhydrazine (DNPH) derivatization spectrophotometrically at 360-385 nm. Results: The oxidative stress induces ROS (p?0.05), MDA (Malondialdehyde) (p?0.05), and protein carbonylation (p?0.01) was significantly higher in HER2-positive BT-474, SK-BR-3, and MDA-MB-453 compared to the HER2-negative MDA-MB-231 and MCF-7 cell lines. Conclusion: We hypothesized that increased oxidative stress in HER2-positive cell lines is due to the oncogenic function of the HER2 and PI3K/Akt signaling activation, resulting in glycolysis induction. It is assumed that HER2-positive cell lines with high ROS levels are more vulnerable to further damage by increased ROS levels induced by pro-oxidant anticancer agents. 04 15 2021 137 142 http://creativecommons.org/licenses/by-nc/4.0 10.32768/abc.202182137-142 https://www.archbreastcancer.com/index.php/abc/article/view/366 https://www.archbreastcancer.com/index.php/abc/article/download/366/484 https://www.archbreastcancer.com/index.php/abc/article/download/366/484