Research from the University of South Florida has reported that nicotine would directly act by speeding the growth of lung cancer.
They explained in the August issue of the Journal of Clinical Investigation, that tobacco smoke contains many agents that cause cancer, and that nicotine itself isn't one of them but they stated that nicotine promotes the growth of existing cancer cells.
The new study has explained that that nicotine influences a key cancer pathway in cells, which may explain how it speeds up cancer growth. The researchers believe that their results may help in the design of better anti-cancer drugs.
Srikumar Chellappan of the University of South Florida, in Tampa, US, who led the study said, "We believe that these components can be targeted for cancer therapy. So we are quite excited about the new therapeutic avenues this study has revealed."
He further explained that nicotine rather than initiating cancer, seems to make existing cancers more aggressive. It was explained that studies done previously had shown, for example, that breast cancer has an increased likelihood of spreading to the lungs of patients who smoke than those who do not. The researchers have found that blocking the receptors for nicotine on the surface of aggressive cancer cells in a laboratory dish had effectively halted their growth. Chellappan has however stressed that cigarette-smoking can nevertheless trigger the development of cancer.
The researchers have explained that it is not yet known how nicotine makes cancers more aggressive, relatively little is known about how it has this effect. Chellappan and his colleagues, had with the intention of finding the solution fore this question, conducted the research, looking into the specific molecules in cancer cells that interact with nicotine.
The researchers explained that they had exposed human lung cancer cells to an amount of nicotine corresponding the amount present in the bloodstream of a person who tends to smokes one pack of cigarettes a day, which had stimulated the cells to replicate. Examining the cells closely it was revealed that nicotine caused a molecule called Raf-1 to bind to a key protein called Rb, which normally suppresses tumors.
Chellappan explained that this interference with the Rb protein's function could make the cancer spread faster. He further explained that 8 out of 10 tumors that were examined by his group had an abnormally high Raf-1 and Rb interactions. , Explaining that this finding lends further support to this idea, Chellappan said, "One area of active research in our laboratory is to identify agents that can prevent the binding of Raf-1 and Rb," also adding that, such drugs could probably have a potent anti-cancer activities.