{'fraction_non_alphanumeric': 0.029891304347826088, 'fraction_numerical': 0.020833333333333332, 'mean_word_length': 5.278409090909091, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 2, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Reactive Oxygen Species (ROS) in Human Breast Cancer cell lines Differing in Malignancy: An Electron Paramagnetic Resonance (EPR) Study

The development of breast cancer is a multifactorial process whose mechanism is still largely unknown. We hypothesized that ROS and oxidative stress may play a critical role in breast cancer etiology and progression and be associated with the proliferation potencies of breast cancer cells. By using the electron paramagnetic resonance (EPR) spin trapping technique, we did real‐time quantitative estimation of ROS production and thus the oxidative stress in three human breast cancer cell lines with known different malignancies (MD‐MBA 468>MCF‐7>T47D). Our data showed the lowest basal superoxide radical (O2−) level in the more malignant MD‐MBA 468 breast cancer cells compared to the other two cell lines. The T47D cells, with the least malignant potency, showed the highest basal level of ROS. Treatment of either 14h hypoxia (1% O2) or 8 Gy gamma‐ray irradiation increased superoxide levels in T47D and MCF‐7 cells but not in the more advanced MD‐MBA 468 cells.