| Millimeter wave (MW) refers to extremely high frequency (30-300GHz) electromagnetic oscillations. A variety of biological effects of millimeter wave have been reported. The studies showed the effects of low intensity MW (10mW/cm2 and less) on cell growth and proliferation, activity of enzymes, state of cell genetic apparatus, function of excitable membrane and other biological systems. The effects could be either local or distant. In 1977, the first clinical trial of MW therapy began in Russia and up to date MW therapy is used widely there. It was reported that more than 50 diseases can be successfully treated with MW, such as gastric and duodenal ulcers, hypertension, bronchitis, wound, cancer and so on. However, the biological effect of MW is so complicated and there is no clear mechanism available to explain the effects elicited by MW exposure. This is also the reason why MW therapy is not expanded globally. So the study of low intensity MW on bioeffects and its mechanism is a hot spot at present in this field.The previously studies on MW emphasized particularly on the phenomenon of its effects and pay little attention to the study in cellular and molecular level. The biological effects of electromagnetic fields have been studied for many years in ourlaboratory and we found that extremely low frequency magnetic fields (ELF MF) at 0.4 mT could suppress the GJIC and lower intensities of ELF MF (0.2 mT) could enhance the suppression of GJIC induced by TPA. However, there are no reports about MW on GJIC. Thus, the first part of this thesis is to explore the possible effects of MW on GJIC and compare this with ELF MF.In the second part, I employed high through put molecular biological technology to determine the differential expression genes respond to MW exposure. What I expect is to make a little bit clearer about the molecular mechanism of the biological effects induced by low intensity of MW and to promote the clinical application of MW. Furthermore, I also expect to promote the study about the safety and public health evaluation of MW exposure.Part I Effects of Millimeter Wave on Gap Junctional Intercellular Communication in HaCaT Keratinocytes.To explore the effect of millimeter wave (30.16GHz) at low intensity on gap junctional intercellular communication, HaCaT keratinocytes were chose as the biological system. Cells were seeded onto 30mm diameter culture dishes which were custom designed for use with a confocal microscope. There were six groups in this study: (1) control (0 mW/cm2 MW, no TPA treatment), (2) 1.0 mW/cm2 MW exposure for 1h, (3) 3.5 mW/cm2 MW exposure for 1h, (4) TPA (5 ng/ml) combined with 1.0 mW/cm2 MW exposure for lh, (5) TPA (5 ng/ml) combined with 3.5 mW/cm2 MW exposure for 1h, (6) TPA (5 ng/ml) treatment for lh. The fluorescence recovery after photobleaching (FRAP) technique was employed to determine the effect of millimetre wave on GJIC with laser confocal scanning microscope.FRAP analysis revealed that exposure to MW at either 1.0 or 3.5 mW/cm2 for lh did not affect GJIC in HaCaT keratinocytes. After the cells exposed to TPA (5ng/ml) for 1h, a significant inhibition of GJIC was detected. However, TPA treatment in combination with MW exposure effectively prevented the inhibition of GJIC induced by TPA. MW radiation at 1.0 mW/cm2 resulted in a statistically significant recovery inGJIC suppression by TPA, but it didn't reach the control level. Meanwhile, 3.5mW/cm2 MW combined with TPA treatment recovered the GJIC suppression approaching the control level. The data suggest that MW has opposite effects on GJIC from ELF MF and it can eliminate or diminish the GJIC suppression induced by TPA. This effect might be related to the intensity of MW exposure.Part II Millimeter Wave Induced Gene Expression Changes in HaCaT KeratinocytesIn order to explore the mechanisms of the biological effects induced by MW exposure, we conducted an in vitro study by using Genechip analysis, a high-through technology, to investigate gene expression pattern in response to this expo...
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