Low radon doses sensitize MCF-7 human breast cancer cells to taxol

We studied whether human breast cancer cells show increased sensitivity to the chemotherapeutic agent taxol when they have been treated with low radiation doses (1.7-3.2 x 10(-3) Gy) from the gas radon. To this end, MCF-7 cells were cultivated in a medium either with or without dissolved radon for 3 days and then exposed to taxol (50 nM). Cells exposed to low doses of radon and then to a concentration of 50 nM of taxol exhibit a lower proliferation rate and a lower viability than cells treated with the same concentration of taxol but not irradiated. These findings indicate an important interaction of radon and taxol in the inhibition of MCF-7 cell growth.