Pre-exposure to 50 Hz-electromagnetic fields enhanced the antiproliferative efficacy of 5-fluorouracil in breast cancer MCF-7 cells

Abstract

Resistance to 5-fluorouracil (5-FU) and its induced immune suppression have prevented its extensive application in the clinical treatment of breast cancer. In this study, the combined effect of 50 Hz-EMFs and 5-FU in the treatment of breast cancer was explored. MCF-7 and MCF10A cells were pre-exposed to 50 Hz-EMFs for 0, 2, 4, 8 and 12 h and then treated with different concentrations of 5-FU for 24 h; cell viability was analyzed by MTT assay and flow cytometry. After pre-exposure to 50 Hz-EMFs for 12 h, apoptosis and cell cycle distribution in MCF-7 and MCF10A cells were detected via flow cytometry and DNA synthesis was measured by EdU incorporation assay. Apoptosis-related and cell cycle-related gene and protein expression levels were monitored by qPCR and western blotting. Pre-exposure to 50 Hz-EMFs for 12 h enhanced the antiproliferative effect of 5-FU in breast cancer cell line MCF-7 in a dose-dependent manner but not in normal human breast epithelial cell line MCF10A. Exposure to 50 Hz-EMFs had no effect on apoptosis and P53 expression of MCF-7 and MCF10A cells, whereas it promoted DNA synthesis, induced entry of MCF-7 cells into the S phase of cell cycle, and upregulated the expression levels of cell cycle-related proteins Cyclin D1 and Cyclin E. Considering the pharmacological mechanisms of 5-FU in specifically disrupting DNA synthesis, this enhanced inhibitory effect might have resulted from the specific sensitivity of MCF7 cells in active S phase to 5-FU. Our findings demonstrate the enhanced cytotoxic activity of 5-FU on MCF7 cells through promoting entry into the S phase of the cell cycle via exposure to 50 Hz-EMFs, which provides a novel method of cancer treatment based on the combinatorial use of 50 Hz-EMFs and chemotherapy.

Detection of Breast Cancer Cells Using Acoustics Aptasensor Specific to HER2 Receptors

“…From our cell viability results in PBS, we can conclude that the SK-BR-3 cell line is stable under laboratory conditions. Our results are consistent with Han et al [26]. They also did not observe a decrease in viability of the adherent breast cancer cell line MCF-7 under laboratory conditions.…”

Induction of apoptosis and ferroptosis by a tumor suppressing magnetic field through ROS-mediated DNA damage

“…Different types of MF are known to be able to sensitize tumor cells to radiotherapy [19] and to reverse chemoresistance. Such examples include ELF-MF in combination with DDP or 5-FU [20,21], SMF with doxorubicin [22], and pulsed EMF with daunorubicin [23]. We have previously reported the sensitizing effect of this tumor suppressing MF to DDP treatment in nephroblastoma [17].…”

Histone deacetylase inhibitor AR‑42 inhibits breast cancer cell growth and demonstrates a synergistic effect in combination with 5‑FU

“…5-FU serves an important role in early breast cancer treatment following adjuvant therapy, breast cancer recurrence and metastasis following palliative care (43,44). It is an anti-metabolic chemotherapeutic agent, acting mainly through the irreversible inhibition of thymidylate synthase (TS), which results in a lack of thymine and the synthesis of non-functional DNA (35).…”