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    The Efficacy of Electrochemotherapy with Dacarbazine on Melanoma Cells
    (Mary Ann Liebert, Inc, 2024) Coskun, Alaaddin; Kayhan, Handan; Senturk, Fatih; Esmekaya, Meric Arda; Canseven, Ayse Gulnihal
    Electrochemotherapy (ECT) involves locally applying electrical pulses to permeabilize cell membranes, using electroporation (EP). This process enhances the uptake of low-permeant chemotherapeutic agents, consequently amplifying their cytotoxic effects. In melanoma treatment, dacarbazine (DTIC) is a cornerstone, but it faces limitations because of poor cell membrane penetration, necessitating the use of high doses, which, in turn, leads to increased side effects. In our study, we investigated the effects of DTIC and EP, both individually and in combination, on the melanoma cell line (SK-MEL-30) as well as human dermal fibroblasts (HDF) using in vitro assays. First, the effects of different DTIC concentrations on the viability of SK-MEL-30 and HDF cells were determined, revealing that DTIC was more effective against melanoma cells at lower concentrations, whereas its cytotoxicity at 1000 mu M was similar in both cell types. Next, an ideal electric field strength of 1500 V/cm achieved a balance between permeability (84%) and melanoma cell viability (79%), paving the way for effective ECT. The combined DTIC-EP (ECT) application reduced IC50 values by 2.2-fold in SK-MEL-30 cells and 2.7-fold in HDF cells compared with DTIC alone. In conclusion, ECT not only increased DTIC's cytotoxicity against melanoma cells but also affected healthy fibroblasts. These findings emphasize the need for cautious, targeted ECT management in melanoma therapy.
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    Radiofrequency Induced Time-Dependent Alterations in Gene Expression and Apoptosis in Glioblastoma Cell Line
    (Wiley, 2025) Tuysuz, Mehmet Zahid; Kayhan, Handan; Saglam, Atiye Seda Yar; Senturk, Fatih; Bagriacik, Emin Umit; Yagci, Munci; Canseven, Ayse Gulnihal
    The widespread use of wireless communication technologies has increased human exposure to radiofrequency electromagnetic fields (RF-EMFs). Considering the brain's close proximity to mobile phones and its entirely electrical transmission network, it emerges as the organ most profoundly impacted by the RF field. This study aims to investigate the potential effects of RF radiation on cell viability, apoptosis, and gene expressions in glioblastoma cells (U118-MG) at different exposure times (1, 24, and 48 h). To achieve this, we designed and implemented an in vitro RF exposure system operating at a frequency of 2.1 GHz, specifically for cell culture studies, with an average specific absorption rate (SAR) of 1.12 +/- 0.18 W/kg determined through numerical dosimetry calculations. Results reveal a significant influence of a 48 h exposure to a 2.1 GHz RF field on U118-MG cell viability, gene expression, and the induction of caspase (CASP) dependent apoptosis. Notably, increased CASP3, CASP8, and CASP9 mRNA levels were observed after 24 and 48 h of RF treatment. However, only the 48 h RF exposure resulted in apoptotic cell death and a significant elevation in the BAX/BCL-2 ratio. This observed effect may be influenced by extended exposure durations surpassing the cell's doubling time. The increased BAX/BCL-2 ratio, which acts as a key switch for apoptosis, and the heterogeneous morphology of the astrocyte-derived U118-MG cell line may also play a role in this effect.