Platinum drug delivery method snuffs cancer's power source

Accumulation of cisplatin in mitochondria of cancer cells--Courtesy of the University of Toronto

If you want to cripple cancer cells, go straight for their power source, according to researchers at MIT and the University of Toronto. The scientists have developed a delivery method for the cancer drug cisplatin that sends it straight to the energy-producing mitochondria of the offending cells.

Cisplatin is a platinum-based chemotherapy long used to treat ovarian and testicular tumors. It blocks the expression of genes in cancer cells, leading to apoptosis, or cell death, over time. But the drug's action is not well understood and can be uncontrolled in its unpackaged form, according to a report in MIT News.

To target cisplatin more specifically to the mitochondria, the researchers "tagged" the drug with a protein fragment that allowed it to accumulate in the organelles, like an address on a mailed letter. The resulting package killed cancer cells that had become resistant to cisplatin, requiring a much smaller dose to do so, according to the study published in the journal Biology & Chemistry.

"People are really interested in using metals as therapeutics, but they're difficult to control, and elucidating the cellular targets of metal-based drugs is challenging because they can interact with so many different biomolecules," said study author Robert Radford of MIT. "By targeting specific cellular organelles with the same therapeutic molecules, we can learn a lot about how the cells respond to a given compound and what cellular consequences metal-based drugs elicit."

The team is developing the method for use with other metal-based drugs, as well as different targets within the cancer cells. The aim is to create more effective treatments with fewer side effects.

- here's the MIT News report