Curley Steven A, Palalon Flavio, Sanders Kelly E, Koshkina Nadezhda V
Department of Surgical Oncology, Baylor College of Medicine, Houston, TX 77030, USA.
Int J Environ Res Public Health. 2014 Sep 3;11(9):9142-53. doi: 10.3390/ijerph110909142.
Exposure of biological subjects to electromagnetic fields with a high frequency is associated with temperature elevation. In our recent studies, we reported that non-invasive radiofrequency (RF) treatment at 13.56 MHz with the field ranging from 1 KeV to 20 KeV/m2 inhibits tumor progression in animals with abdominal tumor xenografts and enhances the anticancer effect of chemotherapy. The RF treatment was followed by temperature elevation in tumors to approximately 46 °C during 10 min of exposure. In contrast, the temperature of normal tissues remained within a normal range at approximately 37 °C. Whether all biological effects of RF treatment are limited to its hyperthermic property remains unclear. Here, we compared how RF and hyperthermia (HT) treatments change the proliferation rate, oxygen consumption and autophagy in malignant and nonmalignant cells.
In the current study, cancer and nonmalignant cells of pancreatic origin were exposed to the RF field or to conventional HT at 46 °C, which was chosen based on our previous in vivo studies of the tumor-specific RF-induced hyperthermia.
Only RF treatment caused declines in cancer cell viability and proliferation. RF treatment also affected mitochondrial function in cancer cells more than HT treatment did and, unlike HT treatment, was followed by the elevation of autophagosomes in the cytoplasm of cancer cells. Importantly, the effects of RF treatment were negligible in nonmalignant cells.
The obtained data indicate that the effects of RF treatment are specific to cancer cells and are not limited to its hyperthermic property.
生物机体暴露于高频电磁场会导致体温升高。在我们最近的研究中，我们报道了在13.56兆赫兹进行非侵入性射频（RF）治疗，场强范围为1千电子伏特至20千电子伏特/平方米，可抑制腹部肿瘤异种移植动物的肿瘤进展，并增强化疗的抗癌效果。在暴露10分钟期间，射频治疗会使肿瘤温度升高至约46°C。相比之下，正常组织的温度保持在约37°C的正常范围内。射频治疗的所有生物学效应是否都局限于其热疗特性仍不清楚。在此，我们比较了射频和热疗（HT）治疗如何改变恶性和非恶性细胞的增殖率、耗氧量和自噬。
在本研究中，将胰腺来源的癌细胞和非恶性细胞暴露于射频场或46°C的传统热疗中，该温度是根据我们之前对肿瘤特异性射频诱导热疗的体内研究选择的。
只有射频治疗导致癌细胞活力和增殖下降。射频治疗对癌细胞线粒体功能的影响也比热疗更大，并且与热疗不同，射频治疗后癌细胞细胞质中的自噬体增加。重要的是，射频治疗对非恶性细胞的影响可忽略不计。
所获得的数据表明，射频治疗的效果对癌细胞具有特异性，且不限于其热疗特性。
