Jamming prostate cancer's transmission.Though most prostate cancers do not metastasize me·tas·ta·size
To be transmitted or transferred by or as if by metastasis.
Spread of cells from the original site of the cancer to other parts of the body where secondary tumors are formed. , seeding new tumors throughout the body, those that do become incurable. But data from a new animal study suggest the possibility of one day checking this cancer's potentially lethal spread with a nontoxic, fruit-derived dietary supplement.
The promising agent? Fragments of pectin pectin, any of a group of white, amorphous, complex carbohydrates that occur in ripe fruits and certain vegetables. Fruits rich in pectin are the peach, apple, currant, and plum. Protopectin, present in unripe fruits, is converted to pectin as the fruit ripens. -- the gelling powder used for generations to set jams and jellies.
Three years ago, researchers at Wayne State University Wayne State University, at Detroit, Mich.; state supported; coeducational; established 1956 as a successor to Wayne Univ. (formed 1934 by a merger of five city colleges). in Detroit chopped up branched molecules of citrus pectin to make linear, twiglike arrays of the sugar galactose. The fragments, they found, could bind to lectins Lectins
A class of proteins of nonimmune origin that bind carbohydrates reversibly and noncovalently without inducing any change in the carbohydrate. Lectins bind a variety of cells having cell-surface glycoproteins (carbohydrate bound proteins) or glycolipids , galactose-seeking proteins on the surface of cancer cells.
Ordinarily, lectins foster a cancer cell's adhesion to the blood vessel wall of any organ it attempts to colonize col·o·nize
v. col·o·nized, col·o·niz·ing, col·o·niz·es
1. To form or establish a colony or colonies in.
2. To migrate to and settle in; occupy as a colony.
3. . By binding those lectins to pectin instead, the researchers had hoped to keep circulating cancer cells in the bloodstream until they died or could be eliminated.
And the strategy worked when researchers injected pectin fragments into mice along with cells from a deadly skin cancer (SN: 3/21/92, p.180). Neither untreated pectin nor galactose alone has proved antimetastatic.
Now the Wayne State team has turned its attention to prostate cancer. Why? Research has shown that when prostate cells turn cancerous, they elevate their production of galactose-binding lectins, notes study leader Kenneth J. Pienta, now at the University of Michigan (body, education) University of Michigan - A large cosmopolitan university in the Midwest USA. Over 50000 students are enrolled at the University of Michigan's three campuses. The students come from 50 states and over 100 foreign countries. in Ann Arbor.
In the March 1 Journal of the National Cancer Institute, his team reports that rats drinking pectin-supplemented water developed prostate metastases to the lung at about half the rate of rats drinking plain water. Moreover, Pienta points out, even when metastases did appear in the highest dose group (whose water contained 1 percent by weight of modified pectin), only about one-tenth as many nascent tumors developed as formed in other animals with metastases.
The nontoxic pectin doesn't affect the growth of established tumors. Rather, assays by Pienta's team suggest, pectin fragments indeed thwart metastasis by preventing tumor cells from adhering to blood vessel walls. Most encouraging, Pienta told Science News, "we have demonstrated in our [assays] that the modified pectin appears to block several different types of cancer from adhering to blood vessels -- including breast cancer, lung cancer, melanoma, kidney, and others."
"We would therefore predict that this [pectin supplementation] would work for just about any cancer -- not just prostate," he says. His group has sent samples of the modified pectin to the National Cancer Institute for additional antimetastasis testing.
In the meantime Adv. 1. in the meantime - during the intervening time; "meanwhile I will not think about the problem"; "meantime he was attentive to his other interests"; "in the meantime the police were notified"
meantime, meanwhile , Pienta cautions cancer victims against attempting to medicate med·i·cate
1. To treat by medicine.
2. To tincture or permeate with a medicinal substance. themselves with pectin. In its off-the-shelf form, he notes, "it's just a dietary fiber and will act like Metamucil. It's only our modification that allows it to be absorbed."