Researchers from the Fox Chase Cancer Center have identified a genetic alteration that occurs thirteen times more frequently in lung tissue of mice exposed to tobacco smoke. The frequency of this genetic alteration and its role in estrogen metabolism could help researchers understand why women who smoke are more susceptible to lung cancer. The findings were presented at the Annual Meeting of the American Association for Cancer Research. The researchers found 53 smoking-induced genetic alterations in mice exposed to tobacco smoke compared to unexposed controls. The most notable finding was the 13-fold overexpression of the enzyme CYP1B1.
"Our research demonstrates that this alteration isn't present in the lung tissue prior to tobacco exposure," said lead author Sibele I. Meireles. "Since we know this alteration is present in human lung tumors, it could be a target for chemopreventive intervention in people at high risk for lung cancer - in particular, active smokers."
Because CYP1B1 activates estradiol, one of the body's natural estrogen hormones, this finding could also help researchers understand more about why female smokers are more susceptible to lung cancer than male smokers.
"The overexpression of CYP1B1 poses an interesting question about gender differences in the development of lung cancer," said Meireles "We hadn't intended to look at gender differences in this study, but this finding about an enzyme so important to estrogen metabolism once again raises the issue of whether estrogen has a role in promoting lung cancer, as it does in breast and ovarian cancer."
