Streckert et al., "Indication of cocarcinogenic
potential of chronic UMTS-modulated radiofrequency exposure in an ethylnitrosourea mouse model," International Journal of Radiation Biology, vol.
(70,71) In brief, the cocarcinogenic experiments, both in mice and hamsters, showed that MM did not develop in animals exposed to subcarcinogenic doses of SV40, although a few hamsters developed lymphomas and sarcomas after a prolonged latency period.
The basis of the cocarcinogenic interaction of SV40 with asbestos has been studied further in an in vitro cell culture system using primary human mesothelial cell lines.
(73,74) The fundamentals of this process are schematically represented in the Figure, designed to depict potential "hit-and-run" cocarcinogenic association of SV40 with asbestos in mesothelial cell transformation.
In addition, there is some evidence that alcohol, even at low doses, increases serum estrogens under certain conditions and that this effect may be another important mechanism involved in alcohol's cocarcinogenic
For bladder cancer, an excess risk was observed primarily among smokers exposed to As in the drinking water, supporting hypotheses that these levels of As are cocarcinogenic (Karagas et al.
These results support the theory that As can act through a cocarcinogenic mechanism of action, exacerbating the genotoxicity and mutagenicity of other compounds.
Over the past few decades, however, several animal studies have indicated that alcohol can have a cocarcinogenic
, or cancer-promoting, effect.
Formaldehyde also showed cocarcinogenic
effects by inhalation, ingestion, and dermal exposure (Dalbey 1982; Iverson 1986; Takahashi et al.
CAT in drinking water was not significantly cocarcinogenic
with MNAN, but ethanol and CAT given in the drinking water was cocarcinogenic
with MNAN and tumorigenic when given without MNAN (16).
In contrast to the data from Loscher's group, the Battelle studies found no evidence for a cocarcinogenic or tumor-promoting effect of MF exposure (12,13).
The marked difference in incidence of palpable tumors between MF-exposed and sham-exposed groups 13 weeks after administration of 10 mg DMBA was reduced during further exposure (22), suggesting that the MF effect was due to a tumor growth-enhancing action rather than to a cocarcinogenic effect.