BET Inhibitors Show Promise Treating Blood Cancer

New drug class offers hope for lymphomas and leukemia.

The discovery of how a new class of anti-cancer drugs kill cancer cells provided insight into how cancer cells are able to become treatment resistance.

When BET inhibitors block BET proteins, it causes the reduction of tumor growth. These new inhibitors are considered a promising new drug for treating blood cancers, such as lymphomas and leukemias.

Researchers have known that BET inhibitors can halt tumor growth, but whether or not the drugs are able to kill cancer cells completely or just pause their growth has been unclear. A study published in Leukemia found that BET inhibitors primarily kill cancer cells through apoptosis.

In order for these inhibitors to successfully kill myeloid leukemia and lymphoma cells, the protein BIM has to be present. Their presence is crucial because BIM brings on apoptosis.

“We found that when apoptosis was impaired, for instance by loss of BIM, the BET inhibitors were no longer effective,” said researcher Zhen Xu. “This suggests that cancer cells that acquire mutations in genes that drive apoptosis will lose sensitivity to BET inhibitors and thus will be able to survive treatment, leading to disease relapse.”

Gaining a better understanding of how the BET inhibitors work may help in the development of different approaches for using these drugs, the study concluded.

“Understanding how the drugs work gives us the opportunity to investigate new treatments, for example by using combination therapies, or altering the dosage and timing of treatment to prevent drug resistance from emerging,” said researcher Stefan Glaser.