Metabolites – A New Piece in the Cancer Development Puzzle
The human body contains and continuously synthesizes about 3000 metabolites, such as triglycerides or cholesterol. As results of screenings of blood or urine, they are markers of a series of diseases and Dr. Arun Sreekumar, a cancer researcher at the Medical College of Georgia Cancer Center, found out that some of them indicate not only the presence of prostate cancer, but its aggressiveness, a tool that could help tailor optimal treatment. The research was done in an effort of proving that metabolites can be used to detect early signs of cancers at the earliest stage possible.
The study was focused on men with a high level of PSA (prostate specific antigen), which present a higher risk of prostate cancer. Since PSA levels are not conclusive in screenings and also can’t help predictions of the disease outcome, the priority of providing a complement of biomarkers that accurately diagnose and categorize the as well as helps the monitoring of the treatment revealed itself. After looking at 1,126 metabolites in 262 samples taken from these men, researchers found high levels of sarcosine in the prostate tissues of men with cancer and even higher in the most aggressive tumors.
The findings were explained by the fact that sarcosine, a modified form of the amino acid glycine could be a dumping ground for excess methyl groups needed to enable chemical changes of genes, proteins and other body components that can affect what and how much they do. The phenomenon is called methylation and is one of the processes that help the development of the embryo but it’s also the thing that makes sarcosine responsible for tumor growth and aggressiveness, though how exactly this works is still under investigation.
Sreekumar is aware of the fact that further research on larger sample groups needs to be done in order to obtain the best biomarkers possible, stating: “In the real world of biomarkers, you want 100 percent sensitivity. If the patient has cancer, you want to pick it up. We need to have a kind of multiplex test where you can test for say10 different entities and have a greater confidence that what you are stating about the tumor is true. Our goal is to develop such a panel and research on sarcosine is a first step toward achieving this.”
He and his team already found another 89 metabolites were different in metastatic prostate cancer compared to localized disease and, including sarcosine, six metabolites linked to increased tumor progression.
This study opens he door for further research, which correlated with the examination of genes expressed by tumors and the proteins expressed by those genes can make for a better understanding of all types of cancers. According to Sreekumar, “It’s basically a systems approach you need to take”.
