An over-the-counter natural remedy derived from honeybee hives arrests the growth of prostate cancer cells and tumors in mice, according to a new paper fromresearchers at the University of Chicago Medicine. Caffeic acid phenethyl ester, or CAPE, is a compound isolated fromhoneybee hive propolis, the resin used by bees to patch up holes inhives. Propolis has been used for centuries as a natural remedy forconditions ranging from sore throats and allergies to burns and cancer . But the compound has not gained acceptance in the clinic due toscientific questions about its effect on cells.
In a paper published in Cancer Prevention Research , researchers combined traditional cancer research methods withcutting-edge proteomics to find that CAPE arrests early-stageprostate cancer by shutting down the tumor cells’ system fordetecting sources of nutrition . “If you feed CAPE to mice daily, their tumors will stop growing.After several weeks, if you stop the treatment, the tumors willbegin to grow again at their original pace,” said Richard B. Jones,PhD, assistant professor in the Ben May Department for CancerResearch and Institute for Genomics and Systems Biology and seniorauthor of the study. “So it doesn’t kill the cancer, but itbasically will indefinitely stop prostate cancer proliferation.” Natural remedies isolated from plant and animal products are oftenmarketed as cure-alls for a variety of maladies, usually based onvague antioxidant and anti-inflammatory claims.
While substancessuch as ginseng or green tea have been occasionally tested inlaboratories for their medicinal properties, scientific evidence iscommonly lacking on the full biological effects of theseover-the-counter compounds. “It’s only recently that people have examined the mechanism bywhich some of these herbal remedies work,” Jones said. “Ourknowledge about what these things are actually doing is a bit of adisconnected hodge-podge of tests and labs and conditions. In theend, you’re left with a broad, disconnected story about whatexactly these things are doing and whether or not they would beuseful for treating disease.” To study the purported anti-cancer properties of CAPE, first authorChih-Pin Chuu (now at the National Health Research Institutes inTaiwan) tested the compound on a series of cancer cell lines. BMW Sat Nav DVD
Evenat the low concentrations expected after oral administration, CAPEsuccessfully slowed the proliferation of cultured cells isolatedfrom human prostate tumors. CAPE was also effective at slowing the growth of human prostatetumors grafted into mice. Six weeks of treatment with the compounddecreased tumor volume growth rate by half, but when CAPE treatmentwas stopped, tumor growth resumed its prior rate. The resultssuggested that CAPE stopped cell division rather than killingcancerous cells. To determine the cellular changes that mediated this effect, theresearchers then used an innovative proteomics technique inventedby Jones and colleagues called the “micro-western array.” Westernblots are a common laboratory tool used to measure the changes inprotein levels and activity under different conditions. Hyundai Sat Nav Manufacturer
But whereasonly one or a few proteins at a time can be monitored with Westernblots, micro-western arrays allow researchers to survey hundreds ofproteins at once from many samples. Chuu, Jones and their colleagues ran micro-western arrays to assessthe impact of CAPE treatment on the proteins of cellular pathwaysinvolved in cell growth – experiments that would have beenprohibitively expensive without the new technique. “What this allowed us to do is screen about a hundred differentproteins across a broad spectrum of signaling pathways that areassociated with all sorts of different outcomes. You can pick upall the pathways that are affected and get a global landscape view,and that’s never been possible before,” Jones said. China Car Stereo Sat Nav
“It would havetaken hundreds of Westerns, hundreds of technicians, and a verylarge amount of money for antibodies.” The micro-western array results allowed researchers to quicklybuild a new model of CAPE’s cellular effects, significantlyexpanding on previous work that studied the compound’s mechanisms.Treatment with CAPE at the concentrations that arrested cancer cellgrowth suppressed the activity of proteins in the p70S6 kinase andAkt pathways, which are important sensors of sufficient nutritionthat can trigger cell proliferation. “It appears that CAPE basically stops the ability of prostatecancer cells to sense that there’s nutrition available,” Jonessaid. “They stop all of the molecular signatures that would suggestthat nutrition exists, and the cells no longer have thatproliferative response to nutrition.” The ability of CAPE to freeze cancer cell proliferation could makeit a promising co-treatment alongside chemotherapies intended tokill tumor cells. Jones cautioned that clinical trials would benecessary before CAPE could be proven effective and safe for thispurpose in humans. But the CAPE experiments offer a precedent tounlock the biological mechanisms of other natural remedies as well,perhaps allowing these compounds to cross over to the clinic.
“A typical problem in bringing some of these herbal remedies intothe clinic is that nobody knows how they act, nobody knows themechanism, and therefore researchers are typically very hesitant toadd them to any pharmaceutical treatment strategy,” Jones said.”Now we’ll actually be able to systematically demonstrate the partsof cell physiology that are affected by these compounds.” Additional References Citations.