With self-building molecule, scientists smother cancer from the inside
Method could lead to therapy for “untreatable” cancer
Burn it with radiation, carve it out with scalpels, shrink it with lasers — these are just some of the ways doctors treat cancer. Now, chemists at the Max Planck Institute for Polymer Research have found a way to suffocate it.
Cancer cells have a nasty habit of adapting to survive treatments specifically designed to eradicate them. But there are certain things no cell can live without: “We want to prevent such adaptation by invading the main pillar of cellular life — how cells breathe,” Dr. David Ng said in a press release on the Institute’s website.
Ng is a group leader in the department for the Synthesis of Macromolecules at the Max Planck Institute, where his team specializes in designing small molecules that self-assemble into larger structures. The concept of a structure that builds itself sounds like an architect’s pipe dream, but it’s old hat for Ng and his team of biochemists, who view these molecules as a possible solution to one of the biggest problems in cancer drug development. In a paper published earlier this year in the Journal of the American Chemical Society, they detail their newest creation: a self-assembling protein that, like a microscopic noose, can suffocate cancer cells from the inside.
Current anticancer treatments tend to fall into one of two categories: small-molecule and large-molecule drugs. That distinction may not sound meaningful — after all, even so-called “large molecules” are still about 10,000 times smaller than the width of a human hair — but when you’re working at the level of a single cell, a micrometer can feel like a mile. Small-molecule drugs, which themselves are 10 times smaller than large-molecule drugs, can easily slip across a cell membrane, but they are usually only able to target specific enzymes, which means cancer cells can just as easily adapt to resist them. Large-molecule drugs, by contrast, can disrupt a cell’s entire metabolism, but their size makes it difficult for them to gain entry in the first place.
The self-assembling molecule designed by Ng and his team offers the best of both worlds: when first administered, this drug is small enough to penetrate the cell membrane, but once it makes contact with the cell’s internal environment, the protein’s molecules join together into fibers that resemble tiny hairs. These fibers block the cell’s ability to absorb oxygen and convert it to energy, and in just a few short hours, even the most aggressive metastatic cells are smothered to death.
With this method, Ng’s team has raised the possibility of a one-size-fits-all approach to treatment — cancer cells may be highly adaptive, but none of them can survive without breathing.
