New research from the Washington University School of Medicine in St Louis (MO, USA) has identified a key factor in the maintenance of brain tumor stem cells, potentially highlighting a new target to prevent the spread of brain cancer. The results were published in Cell Reports recently.
The ability of many brain tumor to regenerate is linked to the presence of cancer stem cells that have evaded initial treatment and have therefore restarted the proliferation of tumor cells. The Washington University team demonstrated that when this process was disrupted, the spread of cancer was also halted.
Albert Kim (Washington University School of Medicine in St Louis) explained: “These tumor stem cells are really the kingpins of cancers — the cells that direct and drive much of the harm done by tumors.”
Within the current study, Kim and his team identified a protein termed SOX2 that is active in both brain tumor stem cells and healthy stem cells in other areas of the body. By utilizing another protein termed CDC20, the research team were able to turn up or down the tumor stem cells’ ability to produce SOX2. Increasing SOX2 levels in this way increased a tumor’s ability to grow once transplanted into mice. However, the elimination of CDC20 in this model resulted in tumor cells that were no longer able to produce SOX2, consequently reducing their ability to generate tumors.
“The rate of growth in some tumors lacking CDC20 dropped by 95% compared with tumors with more typical levels of CDC20,” commented Kim.
By analyzing tumor samples isolated from glioblastoma patients, the lab were also able to link high levels of CDC20 with the shortest survival periods following diagnosis.
“This discovery may help us attack the root of some of the deadliest brain tumors. A successful brain cancer treatment will very likely require blocking the tumor stem cells’ ability to survive and replenish themselves,” added Kim.
Going forward, Kim and his team plan to investigate methods of blocking CDC20 in brain tumors, including investigation of RNA interference, where the production of specific proteins is blocked. This method is already in use in clinical trials as a therapy for other cancers and diseases.