Survey of metabolites finds new prostate cancer marker

February 11, 2009

Howard Hughes Medical Institute researchers have identified a new biological marker present in the urine of patients with prostate cancer that indicates whether the cancer is progressing and spreading.

In experiments reported in the February 12, 2009, issue of the journal Nature, the scientists identified 10 metabolites that become more abundant in prostate cells as cancer progresses. Their studies showed that one of these chemicals, sarcosine, helps prostate cancer cells invade surrounding tissue.

HHMI investigator Arul Chinnaiyan and colleagues at the University of Michigan showed that as prostate cancer develops and progresses, sarcosine levels increase in both tumor cells and urine samples, suggesting that measurements of the metabolite could aid in non-invasively diagnosing the disease. Researchers might also be able to inhibit prostate cancer's spread by designing drugs that manipulate the sarcosine pathway.

The study is the first to analyze the levels of more than 1,000 different metabolites in human tumors. Scientists know that cells undergo complex changes as cancer develops and progresses to metastatic disease. Chinnaiyan's lab, which has extensively analyzed how genes and proteins in prostate cancer cells reflect these changes, thought that profiling cells' metabolites would offer an even more "holistic picture of the molecular alterations that occur," he said.

"This allows us to have more of a systems perspective of cancer development," he noted. "We are also looking at gene and protein markers, for therapeutic consideration, biomarker consideration, and just understanding the biology. We are not sure yet how it's going to sort out, so we're being non-discriminatory with what types of technologies we use."

In the experiments reported in Nature, the scientists used mass spectrometry, a technique that identifies chemicals based on the size and electrical charge of their components, to compare the levels of 1,126 metabolites in healthy prostate tissue, clinically localized prostate cancer, and metastatic prostate cancer. Sixty metabolites were present in tumor cells, but not in benign tissue. Of these, there were about 10 molecules whose levels increased dramatically during cancer progression. "This is proof-of-principle that we can identify metabolites, or panels of metabolites, that might be correlated with aggressive prostate cancer versus slower-growing prostate cancer," Chinnaiyan said.

Having demonstrated that "metabolomic" profiles change in predictable ways as cancer progresses, the group began more focused analyses. "We began to mine the data to look for metabolites that might serve as biomarkers or as therapeutic targets," Chinnaiyan explained. They chose to focus on sarcosine because it was elevated in clinically localized disease and very highly elevated in metastatic cancer.

They confirmed these dramatic increases in a new set of tissue samples, and also found that there was more sarcosine in the urine of patients with prostate cancer than in healthy individuals.

The team went on to test how sarcosine affected the behavior of cancer cells grown in the laboratory. Adding the chemical to prostate cells or manipulating cells' biochemical pathways so they produced more sarcosine on their own caused benign prostate cells to become cancerous and invasive. Conversely, shutting down sarcosine production in cancer cells blocked invasion.

"This really told us that sarcosine is involved biologically in some of the processes of a cancer cell," Chinnaiyan said. The results suggest that drugs that alter sarcosine metabolism might be useful in treating prostate cancer, but Chinnaiyan cautions that these Petri-dish findings still need further validation in animal models.

An important next step, he says, will be to do similar experiments on the other nine potential biomarkers they identified in this study. For reliable diagnosis of aggressive disease, he said, "we need to have panels, not just rely on a single metabolite."
-end-


Howard Hughes Medical Institute

Related Prostate Cancer Articles from Brightsurf:

Low risk of cancer spread on active surveillance for early prostate cancer
Men undergoing active surveillance for prostate cancer have very low rates - one percent or less - of cancer spread (metastases) or death from prostate cancer, according to a recent study published in the Journal of Urology®, an Official Journal of the American Urological Association (AUA).

ESMO 2020: Breast cancer drug set to transform prostate cancer treatment
A drug used to treat breast and ovarian cancer can extend the lives of some men with prostate cancer and should become a new standard treatment for the disease, concludes a major trial which is set to change clinical practice.

Major trial shows breast cancer drug can hit prostate cancer Achilles heel
A drug already licensed for the treatment of breast and ovarian cancers is more effective than targeted hormone therapy at keeping cancer in check in some men with advanced prostate cancer, a major clinical trial reports.

The Lancet: Prostate cancer study finds molecular imaging could transform management of patients with aggressive cancer
Results from a randomised controlled trial involving 300 prostate cancer patients find that a molecular imaging technique is more accurate than conventional medical imaging and recommends the scans be introduced into routine clinical practice.

Common genetic defect in prostate cancer inspires path to new anti-cancer drugs
Researchers found that, in prostate cancer, a mutation leading to the loss of one allele of a tumor suppressor gene known as PPP2R2A is enough to worsen a tumor caused by other mutations.

First prostate cancer therapy to target genes delays cancer progression
For the first time, prostate cancer has been treated based on the genetic makeup of the cancer, resulting in delayed disease progression, delayed time to pain progression, and potentially extending lives in patients with advanced, metastatic prostate cancer, reports a large phase 3 trial.

Men taking medications for enlarged prostate face delays in prostate cancer diagnosis
University of California San Diego School of Medicine researchers report that men treated with medications for benign prostatic hyperplasia (enlarged prostate) experienced a two-year delay in diagnosis of their prostate cancer and were twice as likely to have advanced disease upon diagnosis.

CNIO researchers confirm links between aggressive prostate cancer and hereditary breast cancer
The study has potential implications for families with members suffering from these types of tumours who are at an increased risk of developing cancer.

Distinguishing fatal prostate cancer from 'manageable' cancer now possible
Scientists at the University of York have found a way of distinguishing between fatal prostate cancer and manageable cancer, which could reduce unnecessary surgeries and radiotherapy.

Researchers find prostate cancer drug byproduct can fuel cancer cells
A genetic anomaly in certain men with prostate cancer may impact their response to common drugs used to treat the disease, according to new research at Cleveland Clinic.

Read More: Prostate Cancer News and Prostate Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.