Email updates

Keep up to date with the latest news and content from BMC Cancer and BioMed Central.

Open Access Research article

Overcoming Bcr-Abl T315I mutation by combination of GNF-2 and ATP competitors in an Abl-independent mechanism

Mamduh Khateb1, Nili Ruimi1, Hazem Khamisie1, Yousef Najajreh2, Afsar Mian3, Anna Metodieva3, Martin Ruthardt3 and Jamal Mahajna14*

Author affiliations

1 Cancer Drug Discovery Program, Galilee Technology Center, Migal, P.O.Box 831, Kiryat Shmona, 11016, Israel

2 Faculty of Pharmacy, Al-Quds University, Jerusalem-Abu Dies, Palestine

3 Medizinische Klinik II/Abt. Hämatologie, Klinikum der Goethe-Universität, Theodor-Stern Kai 7, 60590, Frankfurt, Germany

4 Department of Nutritional Sciences, Tel-Hai College, Kiryat Shmona, Israel

For all author emails, please log on.

Citation and License

BMC Cancer 2012, 12:563  doi:10.1186/1471-2407-12-563

Published: 27 November 2012

Abstract

Background

Philadelphia positive leukemias are characterized by the presence of Bcr-Abl fusion protein which exhibits an abnormal kinase activity. Selective Abl kinase inhibitors have been successfully established for the treatment of Ph (+) leukemias. Despite high rates of clinical response, Ph (+) patients can develop resistance against these kinase inhibitors mainly due to point mutations within the Abl protein. Of special interest is the ‘gatekeeper’ T315I mutation, which confers complete resistance to Abl kinase inhibitors. Recently, GNF-2, Abl allosteric kinase inhibitor, was demonstrated to possess cellular activity against Bcr-Abl transformed cells. Similarly to Abl kinase inhibitors (AKIs), GNF-2 failed to inhibit activity of mutated Bcr-Abl carrying the T315I mutation.

Methods

Ba/F3 cells harboring native or T315I mutated Bcr-Abl constructs were treated with GNF-2 and AKIs. We monitored the effect of GNF-2 with AKIs on the proliferation and clonigenicity of the different Ba/F3 cells. In addition, we monitored the auto-phosphorylation activity of Bcr-Abl and JAK2 in cells treated with GNF-2 and AKIs.

Results

In this study, we report a cooperation between AKIs and GNF-2 in inhibiting proliferation and clonigenicity of Ba/F3 cells carrying T315I mutated Bcr-Abl. Interestingly, cooperation was most evident between Dasatinib and GNF-2. Furthermore, we showed that GNF-2 was moderately active in inhibiting the activity of JAK2 kinase, and presence of AKIs augmented GNF-2 activity.

Conclusions

Our data illustrated the ability of allosteric inhibitors such as GNF-2 to cooperate with AKIs to overcome T315I mutation by Bcr-Abl-independent mechanisms, providing a possibility of enhancing AKIs efficacy and overcoming resistance in Ph+ leukemia cells.

Keywords:
Philadelphia chromosome; Bcr-Abl; “gatekeeper” mutation T315I; Allosteric inhibition; Abl kinase inhibitors