How Altering Cells May Help Fight Brain Tumors
Cancer researchers at The Ohio State University have found a way to slow the proliferation of cells that drive the growth of one type of brain tumor.
The finding suggests a new strategy for treating glioblastomas, a usually fatal cancer.
The study found that boosting the levels of a particular molecule – called microRNA-128 – in those tumor cells slows their growth by 80 percent and may make them vulnerable to treatment.
"Our findings suggest that if we can get microRNA-128 into tumor cells of patients, we might help control tumor growth and improve the response to therapy," said Sean Lawler, a research assistant professor of neurological surgery and an investigator with The Ohio State University Comprehensive Cancer Center.
MicroRNAs are small molecules that help cells control the kind and amount of proteins they make. Changes in microRNA levels are believed to play an important role in cancer development.
The study found that microRNA-128, present at greatly reduced levels in tumor cells, inhibits a protein needed by certain tumor cells that behave like stem cells. These stem-like cells are believed responsible for the tumor's persistent growth and resistance to therapy.
Low levels of the microRNA in these cells corresponded with high levels of the protein and with proliferation of the tumor cells. Restoring the microRNA to normal slows the growth of those cells and greatly stunts the growth of tumors when the cells are transplanted into an animal model.
When the researchers artificially raised the level of that molecule to normal in laboratory-grown glioma cells, the cells' growth slowed by 40 percent. And when these altered cells were implanted into mice, they produced tumors that were half the size of those made by normal glioma cells.
In another experiment, tumor cells low in the microRNA grew in culture until they formed large spheres containing thousand of glioma cells. Tumor cells with normal levels of miR128, on the other hand, grew poorly, forming spheres only one-fifth their size.
The findings were published in a recent issue of the journal Cancer Research.
About 10,000 cases of glioblastoma are diagnosed in the United States each year. The average survival is about one year from diagnosis.
The Esther L. Dardinger Endowment for Neuro-oncology and Neurosciences, a American Brain Tumor Association postdoctoral grant, and a Jeffrey Thomas Hayden Foundation Postdoctoral Fellowship supported this research.