New research suggests that E proteins and their antagonists, Id proteins, can play key roles in acute myeloid leukemia (AML).
The study showed that overexpression of the Id2 protein or knockdown of the E2-2 protein can suppress both mixed-lineage leukemia (MLL)-rearranged AML and t(8;21) AML.
These findings, published in Cancer Cell, suggest the Id2/E-protein axis may be a promising therapeutic target for AML.
“There is a particularly urgent need for new, targeted, drug-based therapies for AML, and with every discovery of what’s driving the cancer, we take a step closer to achieving that,” said study author Ricky Johnstone, PhD, of Peter MacCallum Cancer Centre in Melbourne, Victoria, Australia.
“What we found in this case was the suppression of Id2 protein plays an important, and previously unrecognized, role in allowing MLL re-arranged AML cancer cells to take hold and spread. Drugs that influence levels of this protein, or stop it being suppressed by the cancer, could provide a much-needed new avenue to combatting this disease.”
The researchers first found that Id2 regulates leukemia stem cell (LSC) potential. Specifically, low Id2 expression is associated with LSC enrichment, and Id2 overexpression hinders leukemia development.
Further investigation revealed that the fusion protein MLL-AF9 suppresses Id2 and activates E2-2 expression, while E2-2 depletion phenocopies Id2 overexpression in MLL-AF9-AML cells.
The team also found that Id2’s tumor-suppressive function is conserved in t(8;21) AML. And low expression of Id2 and its associated gene signature are associated with poor prognosis in patients with MLL-rearranged AML or t(8;21) AML.
