PURPOSE: To study the possible role of 50 Hz magnetic fields (MF) in UV-induced skin tumourigenesis using a sensitive animal model. MATERIALS AND METHODS: Transgenic mice (line K2) over-expressing the human ornithine decarboxylase (ODC) gene and their non-transgenic littermates were exposed for 10.5 months to UV-only or a combination of UV and a continuous (100 microT) or an intermittent MF with varying intensity (1.3-130 microT). RESULTS: Both MF exposure and transgenicity enhanced the onset rate of macroscopically detectable tumours, but the effect was statistically significant only for the MF exposure (p < 0.015). The number of animals bearing malignant tumours was low and similar in all exposure groups. Epidermal cysts (EC) appeared to be strongly associated with both MF exposure and high ODC activity (transgenic animals). However, EC are not known to be associated with carcinogenesis. The UV-only or combined UV and MF exposure did not affect the ODC activities measured at the end of the exposure. CONCLUSIONS: These results support the proposed tumour-promoting effect of MF, but do not suggest an important role for increased ODC activity in this process.
PURPOSE: To study the possible role of 50 Hz magnetic fields (MF) in UV-induced skin tumourigenesis using a sensitive animal model. MATERIALS AND METHODS:Transgenic mice (line K2) over-expressing the humanornithine decarboxylase (ODC) gene and their non-transgenic littermates were exposed for 10.5 months to UV-only or a combination of UV and a continuous (100 microT) or an intermittent MF with varying intensity (1.3-130 microT). RESULTS: Both MF exposure and transgenicity enhanced the onset rate of macroscopically detectable tumours, but the effect was statistically significant only for the MF exposure (p < 0.015). The number of animals bearing malignant tumours was low and similar in all exposure groups. Epidermal cysts (EC) appeared to be strongly associated with both MF exposure and high ODC activity (transgenic animals). However, EC are not known to be associated with carcinogenesis. The UV-only or combined UV and MF exposure did not affect the ODC activities measured at the end of the exposure. CONCLUSIONS: These results support the proposed tumour-promoting effect of MF, but do not suggest an important role for increased ODC activity in this process.
Authors: Hanna Siiskonen; Kari Törrönen; Timo Kumlin; Kirsi Rilla; Markku I Tammi; Raija H Tammi Journal: J Histochem Cytochem Date: 2011-08-10 Impact factor: 2.479
Authors: L Hämäläinen; G Bart; P Takabe; L Rauhala; A Deen; S Pasonen-Seppänen; E Kärkkäinen; R Kärnä; T Kumlin; M I Tammi; R H Tammi Journal: Histochem Cell Biol Date: 2021-01-23 Impact factor: 4.304