Stanford Medicine researchers have designed an experimental molecule that redirects BCL6, a protein that helps drive B-cell lymphoma, toward activating cancer cells’ programmed-death machinery. Rather than merely blocking BCL6, the approach links it to proteins that can switch on genes involved in cell death.
The molecule, called TCIP3, binds BCL6 on one side and either P300 or CBP on the other. Those proteins add acetyl marks to BCL6 and nearby histones, loosening DNA packaging and helping activate genes that BCL6 normally suppresses. Structural studies led the team to make the connection between the molecule’s two halves more rigid, strengthening the resulting molecular complex.
TCIP3 killed lymphoma cells at very low concentrations in laboratory tests. In mice implanted with human lymphoma cells, twice-daily dosing completely eliminated the treated tumors within 11 days, while tumors in untreated control animals remained. The treated mice showed no obvious toxicity, and blood tests did not show increased inflammatory signals.
The same activity also eliminated germinal centers, clusters of rapidly dividing immune cells that depend heavily on BCL6. That finding points to a possible use beyond lymphoma, although the supplied results establish the molecule’s effects in cells and mice rather than a benefit for patients. The team is also examining whether similar molecular pairings could activate cell death through other cancer-promoting proteins.