In the 9th October edition of Cancer Cell, a paper was released which announced the first molecule that directly attacks just cancer cells (not healthy cells) and pushes them into apoptosis (cell suicide).
Titled “Direct Activation of BAX1 by BTSA1 Overcomes Apoptosis Resistance in Acute Myeloid Leukemia“, the paper describes how the molecule, BTSA1, binds strongly to the activation sites on BAX, which is a protein in cells that triggers apoptosis, increasing the chance that the cell will be able to die properly.
You can think of this like a human messenger trying to send a message to someone (the damaged cell sending a message to itself to self-destruct), and a load of bullies constantly harassing the messenger, tripping her up and standing in her way (the cancer cell’s anti-apoptic proteins bind to the messenger protein). BTSA1 in this case is a strong security guard that travels with the messenger, pushing the bullies out of the way to let her send her message.
In normal cells, when it is time for a cell to die – for example, the telomeres are too short, or damage to the DNA is detected – messages are sent to the BAX protein to tell it to turn on cell suicide mode.
In some cancers, though, Acute Myeloid Leukemia (AML) in this instance, a number of “anti-apoptic” proteins are produced which bind to BAX, so it can’t send its message to start the apoptosis.
In this study, Evripidis Gavathiotis was able to find a molecule which binds stronger to BAX than the AML anti-apoptic proteins do, letting them do their job.
Most importantly, this increase in the strength of the BAX messages only affects those cells that are already trying to commit suicide (the cancer cells)- normal cells are left alone.
In mouse studies, some mice were given AML, and some of those then given the new molecule. Those that received the treatment survived weeks longer than those that did not, with 43% of the treated mice still alive three weeks after the control mice had died and no sign of AML in them.
Even though this treatment was specifically tested on just AML, it is possible that it affects other cancers as well. Dr Gavathiotis has been asked to repeat the test using other cancers to see if this is true.
Recently, the CAR-T cell therapy for cancer was announced which was able to kill cancer cells after some therapy such that a year later 64% of the patients were still in remission. With BTSA1, the chances look even better.