The effects of 2 450 MHz microwave radiation on the proliferation of cultured mouse fibroblast in vitro and possible mechanisms / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effects of 2 450 MHz microwave irradiation on the proliferation of cultured mouse fibroblasts in vitro, and the related gene and protein expressions. Methods Cells from mouse skin were directly radiated with microwaves of different intensities for different periods. The proliferation of fibroblasts was assayed by the MTT method, and the effects of microwave radiation on the fibroblast cell cycle were measured by flow eytometry. The mRNA expression of types Ⅰ and Ⅲ procollagen was detected by real-time RT-PCR. Anti-phosphoryl- ation extracellular-regulated kinase (ERK-1/2) antibody was introduced in immunofluorescence staining analysis to observe any changes in the phosphorylation of fibroblast protein ERK. Results ① 5 W/cm2 or 1.0 W/cm2 irradia- tion for 5 min, 15 min, or 30 min did not significantly decrease fibroblast proliferation, but irradiation at 5 W/cm2 for more than 5min caused a significant decrease in fibroblast proliferation. ②After 5 W/cm2 irradiation for 5 min, the percentage of cells in the G0/G1phase was significantly increased, and ERK was activated immediately after irradia- tion. ③The mRNA expression of type Ⅰ procollagen was down-regulated after microwave irradiation, and the magni- tude of the decreased expression correlated positively with the duration of irradiation. Thirty minutes of microwave ir- radiation at 1 W/cm2 or 5 minutes at 5 W/cm2 significantly down-regulated the mRNA expression of type Ⅰ procolla- gen and the ratio of types Ⅰ and Ⅲ. Conclusion High-intensity microwaves may inhibit the proliferation of fibro-blasts in a dose-dependent manner in vitro and down-regulate procollagen mRNA expression, which might be achieved by activating mitogen-activated protein kinase signal transduction gateways.