Author: Neil Majithia
Institution: Virginia Commonwealth University
Date: July 2007
Scientists from the University of Bath (UK) and Alfacell Corporation (USA) have characterized a molecule found in Northern Leopard frog egg cells that may dramatically improve the prognosis of brain cancer patients. The findings, which were published online in the Journal of Molecular Biology, describe the structure of an enzyme called Amphinase that can detect and bind to the sugary coating of tumor cells, subsequently causing them to die.
Amphinase is a ribonuclease, meaning it cuts strands of RNA into smaller parts, impairing their function in the process. If a cell's RNA functionality is restricted, and the cell is unable to synthesize requisite proteins, it will die. The promising feature of Amphinase is that it displays great specificity for targeting the RNA of tumor cells, and tumor cells alone.
"This is a very exciting molecule," said lead investigator Ravi Acharya, professor of Biology & Biochemistry at the University of Bath. "It is rather like Mother Nature's very own magic bullet for recognizing and destroying cancer cells."
In clinical cases, Amphinase would likely be directly injected into the area where the tumor mass is found. Because the enzyme cannot bind to regular brain cells, the investigators are not worried about the molecule having toxic effects on healthy tissue. This sets the treatment option apart from current methods such as chemotherapy and complex surgery, which often compromise healthy cells.
Tumors tend to integrate well with normal brain tissue, making it difficult for a surgeon to identify the malignant mass and physically remove it. Remnants of the invasive tumor are usually left behind, resulting in a high rate of recurrence. Acharya is confident that Amphinase will be able to counter this problem.
"It is highly specific at hunting and destroying tumor cells, is easily synthesized in the laboratory and offers great hope as a therapeutic treatment of the future."
Without an effective form of treatment currently available, it is estimated that roughly 13,000 Americans die each year as a result of brain tumors. For patients with the most malignant tumors, the five year survival rate is less than 10 percent.
"Amphinase is in the very early stages of development, so it is likely to be several years and many trials before it could be developed into a treatment for patients," the team explained in a joint statement. "Having said that, the early data is promising and through this study we have provided the kind of information needed if approval for use is requested in the future."
Written by Neil Majithia.