Biological Effects Research Of Extremely Low Frequency Electromagnetic Field On Osteosarcoma Cell In Vitro

BACKGROUND: Osteosarcoma(OS) is the most common nonhematologic bone malignancy with a rapid pathogenesis and high mortality in children and adolescents. Surgical treatment we used usually, such as limb salvage surgery and amputation, although these surgeries can relieve their excruciation, improve quality of life, but also let patients suffer serious bodily injury and great mental stress. In spite of the chemotherapy drugs are constantly improved and enhanced, but the long-term transfer rate and metastasis is still as high as 80 %, and the 5-year survival rate is still not satisfied. In recent decades, with the development of new treatments, more and more researchers and clinical medical workers paid attention to the physical therapy approaches, and carried out a series of in-depth study. The relationship of extremely low frequency electromagnetic field(ELF-EMF) with tumor has become the research focus in latest times, and this therapeutic modality has been shown to have great potential in clinical oncology from studies performed in Eastern Europe and Russia. Recent studies overseas have indicated that a specific frequency and intensity of the electromagnetic field(EMF) can inhibit tumor growth very well. Therefore, ours research group intend to study the human osteosarcoma cell line SOSP-9607-F4 in vitro, and exposed to multiple different frequencies and di fferent intensity pulsed electromagnetic field(PEMF), by observing cell proliferation, cell apoptosis, cell cycle, and the invasive ability so as to filter out the two best of the electromagnetic "window", in other words, the parameters is obvious inhibition on cells F4, and as a follow-up of animal experiments and the specific molecular mechanisms of EMF on the basis of the data, the issue has been funded by the National Youth Science Foundation(61102029). In our experimental study, we established a magnetic field group and the control group under the same conditions. The methyl thiazolyl tetrazolium(MTT) assay was used to detect the absorbance(OD value) after the completion of the magnetic field intervention, and the FCM technique was used to analyze the cell cycle and apoptosis and invasion ability. We have chosen one magnetic fields numerical by the SPSS software analysis about the data we collected from the experiment. Based on the all data and upshot, we can draw a conclusion: the specific magnetic fields can inhibit the cell proliferation significant and accelerate the apoptosis and change the cell cycle and slow down the invasive ability. Although, we received some perfect and integrated data and draw an ideal conclusion, but these study only done in vitro, so we have several more works to do in the following test.1. Parameters preliminary screening of the ELF-EMF and the effects of proliferation on human osteosarcoma cells in vitroOBJECTIVE: Established the ELF-EMF group and control group, surveyed the effects of both group cell proliferation, observed their changes in cell morphology and the number of disparities. Finally, two ELF-EMF parameters that restrained the cell better were selected. METHODS: The cells F4 were cultured with RPMI-1640 in incubator which contains the 0.5 % CO2 and the temperature 37.5 ℃,the cells were divided into A~E five groups by different frequency within 5 Hz, 15 Hz, 30 Hz, 40 Hz, 50 Hz, and interposed by the intensity within 0.1 m T, 1 m T, 5 m T, 10 m T one by one. The cells exposure in the ELF-EMF 3 hours per day, lasted 3 days. The MTT method was used to detect the cell proliferation each one group, and the OD values obtained were sorted out and analyzed after interference have done. The results significant difference of two parameters group chosen were observed by microscope and stained by HE staining. RESULTS: Compared with the other EMF group and control, the outcomes discrepancy of EMF B1 and E2 were obvious(P<0.05). CONCLUSIONS: Specific frequency and intensity EMF has significant inhibition on human osteosarcoma cells F4 proliferation, and the EMF 15 Hz,0.1 m T and 50 Hz,1 m T can restrain the cell proliferation distinct.2. The research of the extremely low frequency electromagnetic fields on humanosteosarcoma cells and the parameters selectionObjective: By observing influences of the ELF-EMF on the human osteosarcoma cell F4 in vitro, including the percentage of apoptotic cells, cell cycle and invasion, further optimized the parameters of the ELF-EMF. METHODS: Cultured the cells F4 in vitro under the standard circumstance, and regrouping the cells according to the former experiment 1 after the growing square up to 50 % of the culture bottle, marked the F(15 Hz,0.1 m T) and G(50 Hz,1 m T), setting up the controls group as well, and the stimulation plan and time as the experiment 1. The percentage of the apoptosis and cell cycle diversification of the cell samples were detected by the FCM priority and the ability of invasion by crystal violet staining on the basis of cells through the Transwell membrane and counted after the stimulation accomplished. RESULTS: There were significant diversity about the percentage of the apoptosis among the group F and G and the Control(P<0.05), and the group F and G were much higher than Control. The various of the cell cycle of group F was obviously than G, but the group G has few differences with Controls. After counted the number of the cells through the membrane, the F group and G were much less than the control, and the group F was minimum.CONCLUSIONS: The specific parameters 15 Hz,0.1 m T of the ELF-EMF can induce or promote manifest the apoptosis and affect cell cycle. Moreover, they can reduce the invasion capability of the cells F4 as well.