Designer diet for prostate cancer

For the first time, a research group at the Institute of Food Research led by Professor Richard Mithen has provided an explanation of how eating broccoli might reduce cancer risk based upon studies in men, as opposed to trying to extrapolate from animal models. Prostate cancer is the most common non-skin cancer for males in western countries. The research has provided an insight into why eating broccoli can help men stay healthy.

For the study, published in the online, open-access journal PLoS ONE on July 2, men who were at risk of developing prostate cancer ate either 400g of broccoli or 400g of peas per week in addition to their normal diet over 12 months. Tissue samples were taken from their prostate gland before the start of the trial and after 6 and 12 months, and the expression of every gene measured using Affymetrix microarray technology.

It was found that there were more changes in gene expression in men who were on the broccoli-rich diet than on the pea diet, and these changes may be associated with the reduction in the risk of developing cancer, that has been reported in epidemiological studies.

Previous studies have suggested that the fifty percent of the population who have a GSTM1 gene gain more benefit from eating broccoli than those who lack this gene. The study showed that the presence of the GSTM1 gene had a profound effect on the changes in gene expression caused by eating broccoli.

This study fills the gap between observational studies and studies with cell and animal models. While observational studies have shown that diets rich in cruciferous vegetables may reduce the risk of prostate cancer and other chronic disease, they do not provide an explanation of how this occurs. Evidence from animal and cell models has sought to provide an explanation, but these studies are usually based on high doses that would not normally be experienced as part of the diet.

The results of the study suggested that relatively low amounts of cruciferous vegetables in the diet – a few portions per week – can have large effects on gene expression by changing cell signalling pathways. These signalling pathways are the routes by which information is transmitted through a molecular cascade which amplifies the signal to the nucleus of the cell where gene expression occurs.

The Norwich-based team are currently planning a larger study with men with localised prostate cancer, and will compare the activity of standard broccoli with the special variety of high glucosinolate broccoli used in the current study.

Designer studies for health promotion

"Other fruits and vegetables have been shown to also reduce the risk of prostate cancer and are likely to act through other mechanisms," says Professor Mithen.

"Once we understand these, we can provide much better dietary advice in which specific combinations of fruit and vegetable are likely to be particularly beneficial. Until then, eating two or three portions of cruciferous vegetable per week, and maybe a few more if you lack the GSTM1 gene, should be encouraged."

Citation: Traka M, Gasper AV, Melchini A, Bacon JR, Needs PW, et al. (2008) Broccoli Consumption Interacts with GSTM1 to Perturb Oncogenic Signalling Pathways in the Prostate. PLoS ONE 3(7): e2568. doi:10.1371/journal.pone.0002568

Source: Public Library of Science

Deactivating a cancer growth promoter
Three enzymes called phosphatases that shut down a molecule called SRC-3 (steroid receptor coactivator 3) could provide a new pathway for fighting cancer, particularly tumors of the breast and prostate, said researchers at Baylor College of Medicine in a report that appears in the current issue of the journal Molecular Cell.
Longevity, cancer and diet connected: New research in worms could apply to humans
Researchers have discovered a connection between genes that could hold the key to a longer, healthier life.
Prostate cancer genes behave like those in embryo
Gene activity in prostate cancer is reminiscent of that in the developing fetal prostate, providing further evidence that all cancers are not equal, Johns Hopkins researchers report. The finding could help scientists investigate how to manipulate the genetic program to fight a disease whose biology remains poorly understood despite more than half a century of investigation.
Scientists find second site for prostate cancer gene
Scientists at Wake Forest University School of Medicine and colleagues who are studying a prostate cancer gene called HNF1B have found a second independent site within the HNF1B gene on chromosome 17 (17q12) – increasing the number of genetic variants that may contribute to risk of developing the disease.
Rheb's role in cancer
Two independent papers in the August 15th issue of G&D identify the Rheb GTPase as a novel oncogene and a promising new chemotherapeutic target.
A new biomarker for early cancer detection? Research reveals that 'microRNA' may fit the bill
Scientists at Fred Hutchinson Cancer Research Center have discovered that microRNAs – molecular workhorses that regulate gene expression – are released by cancer cells and circulate in the blood, which gives them the potential to become a new class of biomarkers to detect cancer at its earliest stages. Muneesh Tewari, M.D., Ph.D., and colleagues describe their findings in the July 28 issue of the Proceedings of the National Academy of Sciences.
Tumor-inhibiting protein could be effective in treating leukemia
(PhysOrg.com) -- Angiocidin, a tumor-inhibiting novel protein discovered by Temple University researchers, may also have a role as a new therapeutic application in treating leukemia, according to a study by the researchers.
Outing the outliers: Strategy matches oncogene with subtype of prostate cancer
A new study reveals a previously unidentified candidate oncogene that appears to play a significant role in a subset of prostate cancers. The research, published by Cell Press in the June issue of the journal Cancer Cell, describes a new strategy that can be used to find "outlier" genes in cancer subtypes that are not well understood.

Designer diet for prostate cancer

Related stories:

News discussion: