A diagnosis of brain cancer is often fatal, but a novel technique shows that at least one subtype is associated with a longer life expectancy.

The innovative method subtypes glioblastoma multiforme (GBM) tumor lines by the proteins they express and this discovery could help with better patient prognoses and lead to targeted drug treatments for GBM subtypes.

At the University of Wisconsin (Madison, WI, USA) a group of scientists isolated tumor lines from five human patients and grew them in the laboratory, and then looked for biomarkers specific to each line. They later transplanted the tissue into the brains of mice with compromised immune systems. The antigenic expression of the protein biomarker called 2',3'-Cyclic-nucleotide 3'-phosphodiesterase (CNP), was used to evaluate a clinically-annotated GBM tissue microarray with 115 specimens.

The group found that some patients with the CNP protein lived much longer, as long as 10 years after diagnosis. Through protein expression analysis of developmental neural lineage markers, they identified glioblastoma stem-like cell (GSC) classes resembling oligodendrocyte progenitor cells (OPC) and neural progenitor cells; neural progenitor cells (NPC), and astrocyte progenitor cells. Each of these GSC types exhibited distinct and particular hallmarks found in GBM, including varied cellular and nuclear morphologies, invasive potential, and survival.

John S. Kuo, MD, PhD, an assistant professor and senior author of the study, said, "We found that this protein was correlated with a less invasive type of cancer in mice, and when we looked at samples of human tumors, remarkably, we also found that the less invasive tumors expressed the CNP protein." He added, "The subtyping could lead to more accurate prognosis for patients with a GBM diagnosis. Currently, most subtyping of GBM tumors are based on messenger ribonucleic acid (mRNA), which can be difficult to do, however most hospitals can run assays for proteins, making the test simpler and easier." The study was published on May 15, 2012, in the journal Clinical Cancer Research.

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