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Target modulation by a kinase inhibitor engineered to induce a tandem blockade of the epidermal growth factor receptor (EGFR) and c-Src: the concept of type III combi-targeting.

Rao S, Larroque-Lombard AL, Peyrard L, Thauvin C, Rachid Z, Williams C, Jean-Claude BJ - PLoS ONE (2015)

Bottom Line: Cancer cells are characterized by a complex network of interrelated and compensatory signaling driven by multiple kinases that reduce their sensitivity to targeted therapy.Variation of K1-K2 linkers led to AL776, our first optimized EGFR-c-Src targeting prototype.We now term this new targeting model consisting of designing a kinase inhibitor K1-K2 to target Kin-1 and Kin-2, and to further release two inhibitors K1 and K2 of the latter kinases, "type III combi-targeting".

View Article: PubMed Central - PubMed

Affiliation: Cancer Drug Research Laboratory, Department of Medicine, Division of Medical Oncology, McGill University Health Center/Royal Victoria Hospital, 687 Pine Avenue West Rm M7.19, Montreal, Quebec, H3A 1A1 Canada.

ABSTRACT
Cancer cells are characterized by a complex network of interrelated and compensatory signaling driven by multiple kinases that reduce their sensitivity to targeted therapy. Therefore, strategies directed at inhibiting two or more kinases are required to robustly block the growth of refractory tumour cells. Here we report on a novel strategy to promote sustained inhibition of two oncogenic kinases (Kin-1 and Kin-2) by designing a molecule K1-K2, termed "combi-molecule", to induce a tandem blockade of Kin-1 and Kin-2, as an intact structure and to be further hydrolyzed to two inhibitors K1 and K2 directed at Kin-1 and Kin-2, respectively. We chose to target EGFR (Kin-1) and c-Src (Kin-2), two tyrosine kinases known to synergize to promote tumour growth and progression. Variation of K1-K2 linkers led to AL776, our first optimized EGFR-c-Src targeting prototype. Here we showed that: (a) AL776 blocked EGFR and c-Src as an intact structure using an in vitro kinase assay (IC50 EGFR = 0.12 μM and IC50 c-Src = 3 nM), (b) it could release K1 (AL621, a nanomolar EGFR inhibitor) and K2 (dasatinib, a clinically approved Abl/c-Src inhibitor) by hydrolytic cleavage both in vitro and in vivo, (c) it could robustly inhibit phosphorylation of EGFR and c-Src (0.25-1 μM) in cells, (d) it induced 2-4 fold stronger growth inhibition than gefitinib or dasatinib and apoptosis at concentrations as low as 1 μM, and, (e) blocked motility and invasion at sub-micromolar doses in the highly invasive 4T1 and MDA-MB-231 cells. Despite its size (MW = 1032), AL776 blocked phosphorylation of EGFR and c-Src in 4T1 tumours in vivo. We now term this new targeting model consisting of designing a kinase inhibitor K1-K2 to target Kin-1 and Kin-2, and to further release two inhibitors K1 and K2 of the latter kinases, "type III combi-targeting".

No MeSH data available.


Related in: MedlinePlus

Molecular modeling of AL776.(A) AL776 modeled in the EGFR kinase-binding pocket usingthe Protein Data Bank (PDB) with code 1M17. The quinazoline moiety canbind to the hinge region in a manner analogous to erlotinib, while thelinker-dasatinib portion of AL776, exposed to solvent, can adopt anumber of conformations. The protonated form of the tertiary amine inAL776 can interact with Asp776. (B) AL776 modeled in thec-Src pocket using the PDB with code 3G5D. The dasatinib moiety of AL776binds to the hinge portion of the c-Src ATP binding pocket in a poseidentical to dasatinib while the linker-quinazoline portion of AL776points out into solvent and can adopt many conformations.
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pone.0117215.g006: Molecular modeling of AL776.(A) AL776 modeled in the EGFR kinase-binding pocket usingthe Protein Data Bank (PDB) with code 1M17. The quinazoline moiety canbind to the hinge region in a manner analogous to erlotinib, while thelinker-dasatinib portion of AL776, exposed to solvent, can adopt anumber of conformations. The protonated form of the tertiary amine inAL776 can interact with Asp776. (B) AL776 modeled in thec-Src pocket using the PDB with code 3G5D. The dasatinib moiety of AL776binds to the hinge portion of the c-Src ATP binding pocket in a poseidentical to dasatinib while the linker-quinazoline portion of AL776points out into solvent and can adopt many conformations.

Mentions: One of the primary requirements of the K1-K2 prototype is to possess stronginhibitory potency against Kin-1 and Kin-2, both as an intact molecule as wellas upon undergoing hydrolysis to release K1 directed at Kin-1 and K2 at Kin-2.Having found that AL776 (K1-K2) in an in vitro kinase assaypossessed dual EGFR and c-Src targeting property as an intact structure, it wasimportant to determine how it could probably bind to the EGFR and c-Src kinasedomain. Thus, molecular modeling was used to map the binding of the intactstructure to EGFR or c-Src. AL776 was modeled in the EGFR kinase pocket usingthe 1M17 Protein Data Bank (PDB) structure as a starting point. The quinazolineportion of bound erlotinib [26] in 1M17 was used as a template to construct and minimize a boundpose of AL776. Despite the large size of AL776, the quinazoline moiety couldbind to the 1M17 structure in a pose analogous to erlotinib. In this pose thelinker-dasatinib portion of AL776 points out of the ATP binding pocket towardssolvent, allowing for conformational flexibility. Furthermore, the tertiaryalkyl nitrogen atom of AL776 is in a position such that the protonated form caninteract via a hydrogen-bond/ionic interaction with the carboxylate group ofAsp776. A sample pose of AL776 showing the N+-Asp776 interaction is given inFig. 6A.


Target modulation by a kinase inhibitor engineered to induce a tandem blockade of the epidermal growth factor receptor (EGFR) and c-Src: the concept of type III combi-targeting.

Rao S, Larroque-Lombard AL, Peyrard L, Thauvin C, Rachid Z, Williams C, Jean-Claude BJ - PLoS ONE (2015)

Molecular modeling of AL776.(A) AL776 modeled in the EGFR kinase-binding pocket usingthe Protein Data Bank (PDB) with code 1M17. The quinazoline moiety canbind to the hinge region in a manner analogous to erlotinib, while thelinker-dasatinib portion of AL776, exposed to solvent, can adopt anumber of conformations. The protonated form of the tertiary amine inAL776 can interact with Asp776. (B) AL776 modeled in thec-Src pocket using the PDB with code 3G5D. The dasatinib moiety of AL776binds to the hinge portion of the c-Src ATP binding pocket in a poseidentical to dasatinib while the linker-quinazoline portion of AL776points out into solvent and can adopt many conformations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414309&req=5

pone.0117215.g006: Molecular modeling of AL776.(A) AL776 modeled in the EGFR kinase-binding pocket usingthe Protein Data Bank (PDB) with code 1M17. The quinazoline moiety canbind to the hinge region in a manner analogous to erlotinib, while thelinker-dasatinib portion of AL776, exposed to solvent, can adopt anumber of conformations. The protonated form of the tertiary amine inAL776 can interact with Asp776. (B) AL776 modeled in thec-Src pocket using the PDB with code 3G5D. The dasatinib moiety of AL776binds to the hinge portion of the c-Src ATP binding pocket in a poseidentical to dasatinib while the linker-quinazoline portion of AL776points out into solvent and can adopt many conformations.
Mentions: One of the primary requirements of the K1-K2 prototype is to possess stronginhibitory potency against Kin-1 and Kin-2, both as an intact molecule as wellas upon undergoing hydrolysis to release K1 directed at Kin-1 and K2 at Kin-2.Having found that AL776 (K1-K2) in an in vitro kinase assaypossessed dual EGFR and c-Src targeting property as an intact structure, it wasimportant to determine how it could probably bind to the EGFR and c-Src kinasedomain. Thus, molecular modeling was used to map the binding of the intactstructure to EGFR or c-Src. AL776 was modeled in the EGFR kinase pocket usingthe 1M17 Protein Data Bank (PDB) structure as a starting point. The quinazolineportion of bound erlotinib [26] in 1M17 was used as a template to construct and minimize a boundpose of AL776. Despite the large size of AL776, the quinazoline moiety couldbind to the 1M17 structure in a pose analogous to erlotinib. In this pose thelinker-dasatinib portion of AL776 points out of the ATP binding pocket towardssolvent, allowing for conformational flexibility. Furthermore, the tertiaryalkyl nitrogen atom of AL776 is in a position such that the protonated form caninteract via a hydrogen-bond/ionic interaction with the carboxylate group ofAsp776. A sample pose of AL776 showing the N+-Asp776 interaction is given inFig. 6A.

Bottom Line: Cancer cells are characterized by a complex network of interrelated and compensatory signaling driven by multiple kinases that reduce their sensitivity to targeted therapy.Variation of K1-K2 linkers led to AL776, our first optimized EGFR-c-Src targeting prototype.We now term this new targeting model consisting of designing a kinase inhibitor K1-K2 to target Kin-1 and Kin-2, and to further release two inhibitors K1 and K2 of the latter kinases, "type III combi-targeting".

View Article: PubMed Central - PubMed

Affiliation: Cancer Drug Research Laboratory, Department of Medicine, Division of Medical Oncology, McGill University Health Center/Royal Victoria Hospital, 687 Pine Avenue West Rm M7.19, Montreal, Quebec, H3A 1A1 Canada.

ABSTRACT
Cancer cells are characterized by a complex network of interrelated and compensatory signaling driven by multiple kinases that reduce their sensitivity to targeted therapy. Therefore, strategies directed at inhibiting two or more kinases are required to robustly block the growth of refractory tumour cells. Here we report on a novel strategy to promote sustained inhibition of two oncogenic kinases (Kin-1 and Kin-2) by designing a molecule K1-K2, termed "combi-molecule", to induce a tandem blockade of Kin-1 and Kin-2, as an intact structure and to be further hydrolyzed to two inhibitors K1 and K2 directed at Kin-1 and Kin-2, respectively. We chose to target EGFR (Kin-1) and c-Src (Kin-2), two tyrosine kinases known to synergize to promote tumour growth and progression. Variation of K1-K2 linkers led to AL776, our first optimized EGFR-c-Src targeting prototype. Here we showed that: (a) AL776 blocked EGFR and c-Src as an intact structure using an in vitro kinase assay (IC50 EGFR = 0.12 μM and IC50 c-Src = 3 nM), (b) it could release K1 (AL621, a nanomolar EGFR inhibitor) and K2 (dasatinib, a clinically approved Abl/c-Src inhibitor) by hydrolytic cleavage both in vitro and in vivo, (c) it could robustly inhibit phosphorylation of EGFR and c-Src (0.25-1 μM) in cells, (d) it induced 2-4 fold stronger growth inhibition than gefitinib or dasatinib and apoptosis at concentrations as low as 1 μM, and, (e) blocked motility and invasion at sub-micromolar doses in the highly invasive 4T1 and MDA-MB-231 cells. Despite its size (MW = 1032), AL776 blocked phosphorylation of EGFR and c-Src in 4T1 tumours in vivo. We now term this new targeting model consisting of designing a kinase inhibitor K1-K2 to target Kin-1 and Kin-2, and to further release two inhibitors K1 and K2 of the latter kinases, "type III combi-targeting".

No MeSH data available.


Related in: MedlinePlus