Check Up: Treating cancer by starving cells

Cancer is a disease marked by cells that multiply out of control, a process that requires a lot of energy.

So Thomas Jefferson University researchers have been studying what sounds like a commonsense approach against the killer disease: cutting off its power supply.

The key, said physician Michael P. Lisanti, a research director at Jefferson's Kimmel Cancer Center, is the cellular power plants known as mitochondria.

For decades, many scientists thought cancer cells did not have active mitochondria, deriving their energy instead from other means.

But in new research this month, Lisanti and colleagues report that not only do mitochondria play a crucial role, but that as a result, cancer may be vulnerable to an existing drug.

That drug is Metformin, which has long been used to treat diabetes and acts as a sort of weak mitochondrial "poison," Lisanti said. Indeed, previous studies had found diabetic patients on Metformin were less susceptible to certain cancers, though scientists were not sure why.

In the new Jefferson paper, published in the journal Cell Cycle, the authors describe how they detected supercharged mitochondrial activity in breast cancer cells by using an existing laboratory test - one used to measure similar activity in muscles.

The researchers proposed that this test, known as a COX stain, could be used during surgery to make sure no cancerous tissue remained in the patient.

That's because mitochondrial activity in the support cells that surround tumors is largely absent, the authors found. With the COX stain, surgeons could distinguish between the tumor and its support cells, to make sure they get all of the tumor.

While these support cells, called stromal cells, have little mitochondrial activity, Lisanti said they supply fuel to the mitochondria in cancer cells. With the help of this fuel infusion, the mitochondria in aggressive cancer cells can generate more than five times the energy of a normal cell, he said.

"The cancer cells are basically sucking the energy from the microenvironment," Lisanti said.

Which is why he wants to pull the plug. - Tom Avril