Tumor Suppressor Test p53 Needed to Prescreen Patients for Blood
Researchers at the University of Pennsylvania Schools of Medicine and Veterinary Medicine have determined a way to pre-screen cancer patients to see if they are suitable candidates for proteasome inhibitors, a promising class of anti-cancer drugs. They propose to test for p53, a well-known tumor-suppressor protein that is broken down by cellular machinery called proteasomes. This study appears online in the journal Blood, in advance of print publication in June 2007.
Green staining depicts tumor cells dying after treatment with proteasome inhibitors. Here, the tumor lacks p53, and only a fraction of the cells are killed.
In cancer patients whose tumors do not produce p53, proteasome inhibitors might be ineffective. This patient group could be spared unnecessary treatment with possible harmful side effects. On the other hand, proteasome inhibitors are highly effective against lymphomas that do have the ability to produce p53.
"Proteasomes resemble paper shredders