McMaster University experts discovered in a new study that antipsychotic drugs used to treat schizophrenia also make cancer stem cells differentiate into less-threatening types of cells. This means that they have a reduced potential of developing into new tumors.
The finding was made in a study where scientists were screening hundreds of compounds in order to find one capable of halting the growth of cancer stem cells. These are the cells from which the disease spreads, and from which tumors form anew after previous ones have been surgically removed.
In fact, they constitute a reserve of sort for the cancer. If doctors fail to remove all diseased cells, then this population will differentiate into new cancers, allowing the condition to spread again. This is known as a relapse, Science Daily
Details of the new investigation were published in the May 24 issue of the Cell Press journal Cell. One of the most important things to keep in mind about cancer stem cells is that they are very rare, and also capable of resisting the effects of chemotherapy.
“You have to find something that's truly selective for cancer stem cells. We've been working for some time and it's hard to find that exact formula,” McMaster University expert and lead study author, Mickie Bhatia, explains.
During the study, the team identified a number of 20 compounds that could potentially stave off the development of cancer stem cells. The drug thioridazine, which is commonly used to treat schizophrenia in psychiatric patients, was among them.
The antipsychotic does not work by killing off the cancer, but rather forces all of its stem cells to differentiate, therefore exhausting the disease's ability to regenerate itself. In the case of leukemia (blood cancer), this is done without affecting the natural stem cells in the human blood.
Bhatia now plans to conduct a clinical trial of thioridazine – a chemical already approved by the US Food and Drug Administration for human use – together with standard, anti-cancer therapies. Based on the results, the McMaster team plans to develop a new approach to destroying cancer stem cells.
“We're excited about bringing this drug to patients. We also hope our platform can now be a pipeline for other cancer stem cells drugs,” the investigator concludes.