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Elevated fat and cholesterol levels found in a typical American-style diet play an importantrole in the growth and spread of breast cancer , say researchers at the Kimmel Cancer Center at Jefferson. The study, published in the January issue of The American Journal of Pathology , examines the role of fat and cholesterol in breast cancerdevelopment using a mouse model. The results show that mice fed aWestern diet and predisposed to develop mammary tumors, can developlarger tumors that are faster growing and metastasize more easily,compared to animals eating a control diet. The research team led by cancer biologist Philippe G. Frank, Ph.D., Assistant Professor in theDepartment of Stem Cell Biology and Regenerative Medicine at ThomasJefferson University, was interested in learning about the linkbetween diet and breast cancer. The incidence rate of this canceris five times higher in Western countries than in other developedcountries. Moreover, studies have shown an increase in breastcancer incidence in immigrant populations that relocate from aregion with low incidence. "These facts suggest strongenvironmental influence on breast cancer development," says Dr.Frank. Dietary fat and cholesterol have been shown to be important riskfactors in the development and progression of a number of tumortypes, but diet-based studies in humans have reached contradictoryconclusions. This has led Dr. Frank to turn to animal models ofhuman cancer to examine links between cholesterol, diet, andcancer. The research team turned to the PyMT mouse model to determine therole of dietary fat and cholesterol in tumor development. Thismouse model is believed to closely parallel the pathogenesis ofhuman breast cancer. PyMT mice were placed on a diet that contained21.2 percent fat and 0.2 percent cholesterol, reflective of atypical Western diet. A control group of PyMT mice was fed a normalchow that had only 4.5 percent fat and negligible amounts ofcholesterol. The researchers found that tumors began to develop quickly in micefed the fat/cholesterol-enriched chow. In this group, the number oftumors was almost doubled, and they were 50 percent larger thanthose observed in mice that ate a normal diet. "The consumption ofa Western diet resulted in accelerated tumor onset and increasedtumor incidences, multiplicity, and burden, suggesting an importantrole for dietary cholesterol in tumor formation," Dr. Frank says.There was also a trend towards an increased number of lungmetastasis in mice fed the fatty diet, he adds. To confirm the aggressive nature of the cancer in animals fed acholesterol-rich diet, the researchers examined the levels ofseveral biomarkers of tumor progression and found a signature of amore advanced cancer stage, compared to tumors that developed inthe control group. The researchers also showed that plasma cholesterol levels inexperimental mice that developed tumors were significantly reducedcompared to a group of "wild-type" mice - animals with nopredisposition to develop tumors - that was also fed acholesterol-rich diet. "This suggests that tumor formation wasresponsible for the reduction in blood cholesterol levels observedin our animals," indicates Dr. Frank. Dr. Frank explains the use of cholesterol in breast tumors thisway: "In a neighborhood, if you want to build more houses, you needmore bricks. In tumors, cholesterol provides the bricks that arethe foundation for further growth, and this cholesterol comes fromthe blood. A drop in blood cholesterol may signify that some tumorsare growing as cholesterol provides support for breast cancergrowth." "These data provide new evidence for an increase in cholesterolutilization by breast tumors and thus provides many new avenues forprevention, screening, and treatment," indicates Dr. Frank. Thesefindings suggest that use of cholesterol-lowering drugs, such asstatins, may both protect against breast cancer as well as treatpatients carrying tumors. Since researchers also found that bloodcholesterol levels dropped significantly as tumors began todevelop, the study indicates measuring blood cholesterol levels mayalso be an effective method of screening cancer development. This research team also discovered the same association betweencholesterol and growth of prostate cancer in mice in a study published in the December issue of The American Journal of Pathology. The results of these two new studies indicate, according to Dr.Frank that, "Cholesterol does indeed seem to be an important factorin the regulation of tumor formation in several cancer types." Source: Steve Graff Thomas Jefferson University Additional References Citations. The e-commerce company in China offers quality products such as China LPG Gas Detector Alarm , Gsm Security Alarm System Manufacturer, and more. For more , please visit Alkaline Battery Charger today!
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