Hans-Ulrich Bernard
Hans-Ulrich Bernard, who has studied human papillomavirus for 25 years, points to nicotine as a culprit in unnatural cell division. Daniel A. Anderson / University Communications

Women who smoke are three times more likely to develop cervical cancer, and UC Irvine scientists recently discovered the biological link.

Hans-Ulrich Bernard and colleagues found that nicotine receptors exist in cervical cells. In nerve cells, nicotine interacts with these receptors to act as a stimulant. But in cervical cells, they appear to react with nicotine to encourage cell division, which can lead to cancer.

“Normal cervical epithelial cells appear to become cancerous by taking two hits – growth stimulation by nicotine and infection by the human papillomavirus,” said Bernard, molecular biology & biochemistry professor, regarding his study published online in the International Journal of Cancer.

Bernard has studied HPV for 25 years, specializing in its gene regulation. Most HPV infections are dormant or symptoms occur sporadically. Scientists do not yet fully understand why some HPV infections lead to cancer, while many others don’t.

Tobacco smoke is known to cause lung cancer, as airway surfaces are directly exposed to harmful chemicals in smoke. Nicotine can be absorbed by the body and secreted in the cervix.

Bernard’s research was supported by a $350,000 grant from the Flight Attendant’s Medical Research Institute, which used a settlement with Philip Morris to sponsor research that makes people aware of the dangers of second-hand smoke.

UCI scientists Itzel Calleja-Macias and Mina Kalantari also worked on this study.