Piao C Q, Hei T K
Center for Radiological Research, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
Carcinogenesis. 1993 Mar;14(3):497-501. doi: 10.1093/carcin/14.3.497.
Epidemiological data from uranium miners have not been able to provide a definitive model depicting the interaction between radiation exposure and smoking in the etiology of lung cancers among miners who also smoke. Using the well-characterized C3H 10T1/2 cell system, the toxicity and oncogenic transforming incidence by either gamma-rays or He4 ions, with or without concurrent exposure to cigarette smoke condensate (CSC), were examined. He4 ions had the same energy spectrum as radon. CSC, extracted from 2R1 cigarettes, induced a dose-dependent toxicity and oncogenic transformation incidence in 10T1/2 cells. CSC, in combination with a 2 Gy dose of gamma-rays, induced a toxicity and transforming response that was largely additive in nature. Similar additive modes of interaction were also observed when CSC was combined with He4 ions at a dose that was equivalent in cell killing to that used for gamma-rays. These results provide evidence that radiation and smoking have an additive effect in oncogenic transforming potential and may provide an experimental handle towards an epidemiological uncertainty.
