Glioblastoma: A New Treatment Target?

Reported February 25, 2010

(Ivanhoe Newswire) -- Researchers have identified a protein that is highly expressed in a subgroup of glioblastoma brain tumor cells and show that depletion of this protein increases the survival of mice with these tumors.

Recent studies have increased our understanding of cancer by elucidating some of the differences that exist between tumor cells among patients and even between distinct subsets of tumor cells within the same patient. There seem to be subgroups of cells -- called cancer stem cells or tumor initiating cells -- within tumors that are harder to kill with current therapies than other cells within these tumors. Cancer stem cells may in fact be more important to destroy because they may be responsible for metastasis and for tumor recurrence after therapy. Identifying therapies which specifically target cancer stem cells therefore hold great promise for effective and lasting treatment.

In this study, Dr. Anita B. Hjelmeland and colleagues at the Cleveland Clinic determined that a protein called A20, that was previously implicated in cell survival, is highly expressed in glioblastoma stem cells. They demonstrated that decreasing levels of A20 in these cells reduced their growth in cell culture by inducing cell death. Decreasing A20 levels in animal models of brain tumors also increased survival. Using publicly available datasets from human brain tumor specimens, they also determined that increased levels of A20 are associated with poor patient survival. Together, these studies suggest that targeting A20 could be beneficial for human glioblastoma patients.

Although there continues to be controversy over the cancer stem cell concept, Dr. Hjelmeland was quoted as saying, "Everyone recognizes the need to identify new cancer targets, and this may be achieved by studying subgroups of tumor cells. Using this technique, we identified A20 as an important target. However, we still have a lot of work to do before translation for patient therapies."