Inhibition of pancreatic cancer growth by the dietary isoprenoids farnesol and geraniol

Fruits and vegetables have protective effects against many human cancers, including pancreatic cancer. Isoprenoids are one class of phytochemicals which have antitumor activity, but little is known about their effects on cancer of the pancreas. We tested the hypothesis that isoprenoids would inhibit the growth of pancreatic tumor cells. Significant (60-90%) inhibition of the anchorage-independent growth of human MIA PaCa2 pancreatic tumor cells was attained with 25 mu M farnesol, 25 mu M geranylgeraniol, 100 mu M perillyl amine, 100 mu M geraniol, or 300 mu M perillyl alcohol. We then tested the relative in vivo antitumor activities of dietary farnesol, geraniol, and perillyl alcohol against transplanted PC-1 hamster pancreatic adenocarcinomas. Syrian Golden hamsters fed geraniol or farnesol at 20 g/kg diet exhibited complete inhibition of PC-1 pancreatic tumor growth. Both farnesol and geraniol were more potent than perillyl alcohol, which inhibited tumor growth by 50% at 40 g/kg diet. Neither body weights nor plasma cholesterol levels of animals consuming isoprenoid diets were significantly different from those of pair-fed controls. Thus, farnesol, geraniol, and perillyl alcohol suppress pancreatic tumor growth without significantly affecting blood cholesterol levels. These dietary isoprenoids warrant further investigation for pancreatic cancer prevention and treatment.