[Effects of selenium dioxide on regulatory regions P250 of c-fos gene].

BACKGROUND & OBJECTIVE: This study was designed to investigate the impact of selenium dioxide (SeO2) on regulatory regions P250 of c-fos gene and to seek possible regulation mechanism. METHODS: HeLa cells were transfected with plasmids containing upstream regulating regions of c-fos chloramphenicol acetyl-transferase (CAT). The cells were cultured in various concentration of selenium dioxide. CAT expression in transfected cells was observed. RESULTS: After transfected HeLa cells were exposed to selenium dioxide, CAT expression showed obvious increase, especially in 10 micromol/L and 30 micromol/L selenium dioxide group (P< 0.05). CONCLUSION: Trough affecting regulatory regions P250 of c-fos gene, Selenium dioxide plays biological effect of regulating tumor cells. Selenium dioxide possibly has anti-tumor effects.

[Effect of electromagnetic pulse irradiation on mice reproduction].

OBJECTIVE: To evaluate the effect of electromagnetic pulse (EMP) irradiation on mice reproduction. METHODS: Female/male Kunming mice, 6 - 8 weeks old, prior to mating, or female after pregnancy were treated with whole body irradiation by 6 x 10(4) V/m electromagnetic pulse (EMP) for five times. The pregnant mice were killed on the 18th days, and teratological markers were analysed. RESULTS: EMP irradiation caused no significant changes in most of female organ weight and organ/body weight ratio. But it caused significant shortening in tail length of live foetus in the female mice before conception (prior to mating) or after pregnancy (P < 0.05), and obvious decrease in male offspring ratio (0.85 +/- 0.09 vs 1.09 +/- 0.17, P < 0.05). The male offspring ratio also significantly decreased (0.76 +/- 0.18 vs 1.09 +/- 0.17, P < 0.01) after male mice irradiated by EMP. The tail length of live foetus was shortened and male offspring sex ratio was increased after both male and female mice were irradiated by EMP. EMP irradiation also caused a significantly higher fetal death rate than normal control (P < 0.05). The embryo absorption rate was increased after irradiation except that was decreased in male mice. CONCLUSION: EMP irradiation has effect on pregnancy and offspring development in both male and female mice before mating and in female mice after pregnancy.

[Apoptosis of human lung carcinoma cell line GLC-82 induced by high power electromagnetic pulse].

BACKGROUND & OBJECTIVE: Electromagnetic pulse (EMP) could be used for sterilization of food and the efficiency is higher than 2450 MHz continuous microwave done. This study was designed to evaluate the effect of electromagnetic pulse (EMP) on apoptosis of human lung carcinoma cell line GLC-82, so that to explore and develop therapeutic means for cancer. METHODS: The injury changes in GLC-82 cells after irradiated with EMP (electric field intensity was 60 kV/m, 5 pulses/2 min) were analyzed by cytometry, MTT chronometry, and flow cytometry. The immunohistochemical SP staining was used to determine the expressions of bcl-2 protein and p53 protein. The stained positive cells were analyzed by CMIAS-II image analysis system at a magnification 400. All data were analyzed by SPSS8.0 software. RESULTS: EMP could obviously inhibited proliferation and activity of lung carcinoma cell line GLC-82. The absorbance value (A570) of MTT decreased immediately, at 0 h, 1 h, and 6 h after the GLC-82 cells irradiated by EMP as compared with control group. The highest apoptosis rate was found to reach 13.38% by flow cytometry at 6 h after EMP irradiation. Down-regulation of bcl-2 expression and up-regulation of p53 expression were induced by EMP. CONCLUSION: EMP promotes apoptosis of GLC-82 cells. At same time, EMP can down-regulate bcl-2 expression and up-regulate p53 expression in GLC-82 cells. The bcl-2 and the p53 protein may involve the apoptotic process.