Multidomain targeting of Bcr-Abl by disruption of oligomerization and tyrosine kinase inhibition: toward eradication of CML.

The oncoprotein Bcr-Abl, the causative agent of chronic myeloid leukemia (CML), requires homo-oligomerization via a coiled-coil domain to function [Bartram, C. R.; et al.

Disrupting BCR-ABL in combination with secondary leukemia-specific pathways in CML cells leads to enhanced apoptosis and decreased proliferation.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by expression of the fusion gene BCR-ABL following a chromosomal translocation in the hematopoietic stem cell. Therapeutic management of CML uses tyrosine kinase inhibitors (TKIs), which block ABL-signaling and effectively kill peripheral cells with BCR-ABL. However, TKIs are not curative, and chronic use is required in order to treat CML.

Enhanced and selective killing of chronic myelogenous leukemia cells with an engineered BCR-ABL binding protein and imatinib.

The oncoprotein Bcr-Abl stimulates prosurvival pathways and suppresses apoptosis from its exclusively cytoplasmic locale, but when targeted to the mitochondrial compartment of leukemia cells, Bcr-Abl was potently cytotoxic. Therefore, we designed a protein construct to act as a mitochondrial chaperone to move Bcr-Abl to the mitochondria. The chaperone (i.

Development of an effective therapy for chronic myelogenous leukemia.

Targeted small-molecule drugs have revolutionized treatment of chronic myeloid leukemia (CML) during the last decade. These agents interrupt a constitutively active BCR-ABL, the causative agent for CML, by interfering with adenosine 5' triphosphate-dependent ABL tyrosine kinase. Although the efficacy of tyrosine kinase inhibitors (TKIs) has resulted in overall survival of greater than 90%, TKIs are not curative.

Improved coiled-coil design enhances interaction with Bcr-Abl and induces apoptosis.

The oncoprotein Bcr-Abl drives aberrant downstream activity through trans-autophosphorylation of homo-oligomers in chronic myelogenous leukemia (CML).(1, 2) The formation of Bcr-Abl oligomers is achieved through the coiled-coil domain at the N-terminus of Bcr.(3, 4) We have previously reported a modified version of this coiled-coil domain, CCmut2, which exhibits disruption of Bcr-Abl oligomeric complexes and results in decreased proliferation of CML cells and induction of apoptosis.

Disruption of Bcr-Abl coiled coil oligomerization by design.

Oligomerization is an important regulatory mechanism for many proteins, including oncoproteins and other pathogenic proteins. The oncoprotein Bcr-Abl relies on oligomerization via its coiled coil domain for its kinase activity, suggesting that a designed coiled coil domain with enhanced binding to Bcr-Abl and reduced self-oligomerization would be therapeutically useful. Key mutations in the coiled coil domain of Bcr-Abl were identified that reduce homo-oligomerization through intermolecular charge-charge repulsion yet increase interaction with the Bcr-Abl coiled coil through additional salt bridges, resulting in an enhanced ability to disrupt the oligomeric state of Bcr-Abl.

Electroporation-mediated gene transfer to the developing mouse inner ear.

The mammalian inner ear forms from a thickened patch of head ectoderm called the otic placode. The placodal ectoderm invaginates to form a cup whose edges cinch together to establish a fluid-filled sac called the otic vesicle or otocyst. The progenitor cells lining the otocyst lumen will give rise to sensory and non-sensory cells of the inner ear.

Functional auditory hair cells produced in the mammalian cochlea by in utero gene transfer.

Sensory hair cells in the mammalian cochlea convert mechanical stimuli into electrical impulses that subserve audition. Loss of hair cells and their innervating neurons is the most frequent cause of hearing impairment. Atonal homologue 1 (encoded by Atoh1, also known as Math1) is a basic helix-loop-helix transcription factor required for hair-cell development, and its misexpression in vitro and in vivo generates hair-cell-like cells.