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Reversal of oncogene transformation and suppression of tumor growth by the novel IGF1R kinase inhibitor A-928605.

Pappano WN, Jung PM, Meulbroek JA, Wang YC, Hubbard RD, Zhang Q, Grudzien MM, Soni NB, Johnson EF, Sheppard GS, Donawho C, Buchanan FG, Davidsen SK, Bell RL, Wang J - BMC Cancer (2009)

Bottom Line: A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo.This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo.A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models.

View Article: PubMed Central - HTML - PubMed

Affiliation: Cancer Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064, USA. bill.pappano@abbott.com

ABSTRACT

Background: The insulin-like growth factor (IGF) axis is an important signaling pathway in the growth and survival of many cell and tissue types. This pathway has also been implicated in many aspects of cancer progression from tumorigenesis to metastasis. The multiple roles of IGF signaling in cancer suggest that inhibition of the pathway might yield clinically effective therapeutics.

Methods: We describe A-928605, a novel pyrazolo [3,4-d]pyrimidine small molecule inhibitor of the receptor tyrosine kinases (IGF1R and IR) responsible for IGF signal transduction. This compound was first tested for its activity and selectivity via conventional in vitro kinome profiling and cellular IGF1R autophosphorylation. Additionally, cellular selectivity and efficacy of A-928605 were analyzed in an IGF1R oncogene-addicted cell line by proliferation, signaling and microarray studies. Finally, in vivo efficacy of A-928605 was assessed in the oncogene-addicted cell line and in a neuroblastoma model as a single agent as well as in combination with clinically approved therapeutics targeting EGFR in models of pancreatic and non-small cell lung cancers.

Results: A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo. This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo. A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models.

Conclusion: These results suggest that a selective IGF1R inhibitor such as A-928605 may provide a useful clinical therapeutic for IGF pathway affected tumors and warrants further investigation.

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Related in: MedlinePlus

A-928605 is a potent inhibitor of IGF signal transduction as seen in a model transformed cell line.A, Parental NIH 3T3 cells compared to the vector control and CD8-IGF1R lines show a strong pIGF1R signal in the CD8-IGF1R line. All cells were grown in normal growth media containing 10% FBS. B, Cells were treated for 1 hour with A-928605 in a dose response analysis as shown. The CD8-IGF1R fusion protein runs as a doublet [25]. C and D, Three day proliferation assay in the NIH-3T3 vector control cells (C) or CD8-IGF1R cells (D) with increasing amounts of six clinical small molecule inhibitors and A-928605. Compounds were run in duplicate at each indicated concentration. Results are representative of 5 separate assays. Intended targets of each small molecule inhibitor are as follows: lapatinib, ERBB2 and EGFR; gefitinib, EGFR; dasatinib, ABL and SRC; Sorafinib, multi-targeted; imatinib, ABL and KIT; erlotinib, EGFR.
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Figure 2: A-928605 is a potent inhibitor of IGF signal transduction as seen in a model transformed cell line.A, Parental NIH 3T3 cells compared to the vector control and CD8-IGF1R lines show a strong pIGF1R signal in the CD8-IGF1R line. All cells were grown in normal growth media containing 10% FBS. B, Cells were treated for 1 hour with A-928605 in a dose response analysis as shown. The CD8-IGF1R fusion protein runs as a doublet [25]. C and D, Three day proliferation assay in the NIH-3T3 vector control cells (C) or CD8-IGF1R cells (D) with increasing amounts of six clinical small molecule inhibitors and A-928605. Compounds were run in duplicate at each indicated concentration. Results are representative of 5 separate assays. Intended targets of each small molecule inhibitor are as follows: lapatinib, ERBB2 and EGFR; gefitinib, EGFR; dasatinib, ABL and SRC; Sorafinib, multi-targeted; imatinib, ABL and KIT; erlotinib, EGFR.

Mentions: We originally recognized that the pyrazolopyrimidine class of kinase inhibitors possessed moderate potency for IGF1R during a high throughput screen of our compound repository [20]. A-928605 (Figure 2A) is an optimized pyrazolopyrimidine that has previously been reported to have an IGF1R in vitro enzymatic IC50 of 37 nM as well as an IC50 value of 90 nM for inhibition of cellular IGF1R phosphorylation induced by IGF1 in A431 tumor cells [20]. This small molecule inhibitor was tested against an in vitro panel of 156 kinases for potential enzyme inhibition and was found to have a Ki of less than 10 nM in only 5 of those kinases (Figure 2B). Two of these five kinases, IGF1R and the closely related IR, were desired targets and confirmed by cellular analysis. However, the three other kinase activities with Ki values below 10 nM could not be confirmed in cellular assays. For example, A-928605 has an IC50 value for inhibition of A-431 and HCC827 cellular epidermal growth factor receptor (EGFR) phosphorylation of > 10 μM.


Reversal of oncogene transformation and suppression of tumor growth by the novel IGF1R kinase inhibitor A-928605.

Pappano WN, Jung PM, Meulbroek JA, Wang YC, Hubbard RD, Zhang Q, Grudzien MM, Soni NB, Johnson EF, Sheppard GS, Donawho C, Buchanan FG, Davidsen SK, Bell RL, Wang J - BMC Cancer (2009)

A-928605 is a potent inhibitor of IGF signal transduction as seen in a model transformed cell line.A, Parental NIH 3T3 cells compared to the vector control and CD8-IGF1R lines show a strong pIGF1R signal in the CD8-IGF1R line. All cells were grown in normal growth media containing 10% FBS. B, Cells were treated for 1 hour with A-928605 in a dose response analysis as shown. The CD8-IGF1R fusion protein runs as a doublet [25]. C and D, Three day proliferation assay in the NIH-3T3 vector control cells (C) or CD8-IGF1R cells (D) with increasing amounts of six clinical small molecule inhibitors and A-928605. Compounds were run in duplicate at each indicated concentration. Results are representative of 5 separate assays. Intended targets of each small molecule inhibitor are as follows: lapatinib, ERBB2 and EGFR; gefitinib, EGFR; dasatinib, ABL and SRC; Sorafinib, multi-targeted; imatinib, ABL and KIT; erlotinib, EGFR.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2749869&req=5

Figure 2: A-928605 is a potent inhibitor of IGF signal transduction as seen in a model transformed cell line.A, Parental NIH 3T3 cells compared to the vector control and CD8-IGF1R lines show a strong pIGF1R signal in the CD8-IGF1R line. All cells were grown in normal growth media containing 10% FBS. B, Cells were treated for 1 hour with A-928605 in a dose response analysis as shown. The CD8-IGF1R fusion protein runs as a doublet [25]. C and D, Three day proliferation assay in the NIH-3T3 vector control cells (C) or CD8-IGF1R cells (D) with increasing amounts of six clinical small molecule inhibitors and A-928605. Compounds were run in duplicate at each indicated concentration. Results are representative of 5 separate assays. Intended targets of each small molecule inhibitor are as follows: lapatinib, ERBB2 and EGFR; gefitinib, EGFR; dasatinib, ABL and SRC; Sorafinib, multi-targeted; imatinib, ABL and KIT; erlotinib, EGFR.
Mentions: We originally recognized that the pyrazolopyrimidine class of kinase inhibitors possessed moderate potency for IGF1R during a high throughput screen of our compound repository [20]. A-928605 (Figure 2A) is an optimized pyrazolopyrimidine that has previously been reported to have an IGF1R in vitro enzymatic IC50 of 37 nM as well as an IC50 value of 90 nM for inhibition of cellular IGF1R phosphorylation induced by IGF1 in A431 tumor cells [20]. This small molecule inhibitor was tested against an in vitro panel of 156 kinases for potential enzyme inhibition and was found to have a Ki of less than 10 nM in only 5 of those kinases (Figure 2B). Two of these five kinases, IGF1R and the closely related IR, were desired targets and confirmed by cellular analysis. However, the three other kinase activities with Ki values below 10 nM could not be confirmed in cellular assays. For example, A-928605 has an IC50 value for inhibition of A-431 and HCC827 cellular epidermal growth factor receptor (EGFR) phosphorylation of > 10 μM.

Bottom Line: A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo.This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo.A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models.

View Article: PubMed Central - HTML - PubMed

Affiliation: Cancer Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064, USA. bill.pappano@abbott.com

ABSTRACT

Background: The insulin-like growth factor (IGF) axis is an important signaling pathway in the growth and survival of many cell and tissue types. This pathway has also been implicated in many aspects of cancer progression from tumorigenesis to metastasis. The multiple roles of IGF signaling in cancer suggest that inhibition of the pathway might yield clinically effective therapeutics.

Methods: We describe A-928605, a novel pyrazolo [3,4-d]pyrimidine small molecule inhibitor of the receptor tyrosine kinases (IGF1R and IR) responsible for IGF signal transduction. This compound was first tested for its activity and selectivity via conventional in vitro kinome profiling and cellular IGF1R autophosphorylation. Additionally, cellular selectivity and efficacy of A-928605 were analyzed in an IGF1R oncogene-addicted cell line by proliferation, signaling and microarray studies. Finally, in vivo efficacy of A-928605 was assessed in the oncogene-addicted cell line and in a neuroblastoma model as a single agent as well as in combination with clinically approved therapeutics targeting EGFR in models of pancreatic and non-small cell lung cancers.

Results: A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo. This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo. A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models.

Conclusion: These results suggest that a selective IGF1R inhibitor such as A-928605 may provide a useful clinical therapeutic for IGF pathway affected tumors and warrants further investigation.

Show MeSH
Related in: MedlinePlus