Leukemia Breast Cancers Suppressed by Single Protein

Targeting a single protein can help combat both breast cancers and leukemia, according to two new reports. The single protein, HSP90, acts as a chaperone to protect other cellular proteins.

The study’s findings were published online January 23, 2012, in the Journal of Experimental Medicine. A team of investigators led by Ute Moll from the University of Gottingen (Germany) discovered that suppressing HSP90 activity rendered normally protected proteins susceptible to attack and destruction. One of these proteins--called migration inhibitory factor--fuels the growth of breast tumors. HSP90 inhibitors slowed the growth of migration inhibitory factor (MIF)-expressing breast tumors in mice but had little effect on tumors lacking MIF.

HSP90 inhibitors also look promising for certain forms of leukemia, according to a study by David Weinstock and coworkers at the Dana-Farber Cancer Institute (Boston, MA, USA). They demonstrated that HSP90 inhibitors slowed the growth of leukemia driven by hyperactive versions of the enzyme JAK2 (Janus kinase 2), many of which become resistant to JAK2-blocking drugs. The HSP90 inhibitors delayed the growth of resistant leukemia cells in mice.

According to the scientists, this research suggests that HSP90 may represent a therapeutic target for a range of cancers.

Related Links:
University of Göttingen
Dana-Farber Cancer Institute