TY - JOUR
T1 - MP470, a novel receptor tyrosine kinase inhibitor, in combination with Erlotinib inhibits the HER family/PI3K/Akt pathway and tumor growth in prostate cancer
AU - Qi, Wenqing
AU - Cooke, Larry S.
AU - Stejskal, Amy
AU - Riley, Christopher
AU - Della Croce, Kimiko
AU - Saldanha, Jose W.
AU - Bearss, David
AU - Mahadevan, Daruka
N1 - Funding Information:
It is our pleasure to acknowledge the National Foundation of Cancer Research for providing funding for this project. Also we wish to thank Dr. P. Tadikamalla and Dr. E. Mash of the Synthetic Chemistry Shared Service, Arizona Cancer Center for providing MP470.
PY - 2009/5/11
Y1 - 2009/5/11
N2 - Background: Prostate cancer is a common disease in men and at present there is no effective therapy available due to its recurrence despite androgen deprivation therapy. The epidermal growth factor receptor family (EGFR/HER1, HER2/neu and HER3)/PI3K/Akt signaling axis has been implicated in prostate cancer development and progression. However, Erlotinib, an EGFR tyrosine kinase inhibitor, has less effect on proliferation and apoptosis in prostate cancer cell lines. In this study, we evaluate whether MP470, a novel receptor tyrosine kinase inhibitor alone or in combination with Erlotinib has inhibitory effect on prostate cancer in vitro and in vivo. Methods: The efficacy of MP470or MP470 plus Erlotinib was evaluated in vitro using three prostate cancer cell lines by MTS and apoptosis assays. The molecular mechanism study was carried out by phosphorylation antibody array, immunoblotting and immunohistochemistry. A LNCaP mouse xenograft model was also used to determine the tumor growth inhibition by MP470, Erlotinib or the combination treatments. Results: MP470 exhibits low μM IC50 in prostate cancer cell lines. Additive effects on both cytotoxicity and induction of apoptosis were observed when LNCaP were treated with MP470 in combination with Erlotinib. This combination treatment completely inhibited phosphorylation of the HER family members (HER1, 2, 3), binding of PI3K regulatory unit p85 to HER3 and downstream Akt activity even after androgen depletion. Furthermore, in a LNCaP mouse xenograft model, the MP470-Erlotinib combination produced 30-65% dose-dependent tumor growth inhibition (TGI). Conclusion: We propose that MP470-Erlotinib targets the HER family/PI3K/ Akt pathway and may represent a novel therapeutic strategy for prostate cancer.
AB - Background: Prostate cancer is a common disease in men and at present there is no effective therapy available due to its recurrence despite androgen deprivation therapy. The epidermal growth factor receptor family (EGFR/HER1, HER2/neu and HER3)/PI3K/Akt signaling axis has been implicated in prostate cancer development and progression. However, Erlotinib, an EGFR tyrosine kinase inhibitor, has less effect on proliferation and apoptosis in prostate cancer cell lines. In this study, we evaluate whether MP470, a novel receptor tyrosine kinase inhibitor alone or in combination with Erlotinib has inhibitory effect on prostate cancer in vitro and in vivo. Methods: The efficacy of MP470or MP470 plus Erlotinib was evaluated in vitro using three prostate cancer cell lines by MTS and apoptosis assays. The molecular mechanism study was carried out by phosphorylation antibody array, immunoblotting and immunohistochemistry. A LNCaP mouse xenograft model was also used to determine the tumor growth inhibition by MP470, Erlotinib or the combination treatments. Results: MP470 exhibits low μM IC50 in prostate cancer cell lines. Additive effects on both cytotoxicity and induction of apoptosis were observed when LNCaP were treated with MP470 in combination with Erlotinib. This combination treatment completely inhibited phosphorylation of the HER family members (HER1, 2, 3), binding of PI3K regulatory unit p85 to HER3 and downstream Akt activity even after androgen depletion. Furthermore, in a LNCaP mouse xenograft model, the MP470-Erlotinib combination produced 30-65% dose-dependent tumor growth inhibition (TGI). Conclusion: We propose that MP470-Erlotinib targets the HER family/PI3K/ Akt pathway and may represent a novel therapeutic strategy for prostate cancer.
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U2 - 10.1186/1471-2407-9-142
DO - 10.1186/1471-2407-9-142
M3 - Article
C2 - 19432987
AN - SCOPUS:66749185251
SN - 1471-2407
VL - 9
JO - BMC Cancer
JF - BMC Cancer
M1 - 142
ER -