You're right :( The article is pretty remarkable for its breadth. Let me try to give a synopsis:
They synthesize a new biotinylated ketone. They determine that this compound binds to fascin, which has some molecular biological background as something that bundles actin, and some population biological background as something that corresponds with worse survival in breast cancer. They then develop the crystal structure for fascin both with and without their new molecule, and they show that their macroketone binds to the actin binding sites on fascin. They also use electron microscopy to determine that their new molecule indeed appears to disrupt actin bundling by fascin.
They then gave to immune-deficient mice human breast cancer cells. These cells typically metastasize aggressively. They gave the mice a 'placebo' and/or shRNA against fascin and/or their new macroketone. The shRNA and their macroketone successfully cut the metastatic burden by ~50-80%. (shRNA ultimately leads to downregulation of the mRNA of target proteins, so their shRNA should reduce fascin synthesis while their macroketone reduces the function of already-made fascin.)
It's not a silver bullet against metastatic breast cancer, but it's an impressively complete story for one paper. And promising, perhaps, as a therapeutic.
