Dasatinib reduces FAK phosphorylation increasing the effects of RPI-1 inhibition in a RET/PTC1-expressing cell line

Molecular Cancer

Research

Giuliana Cassinelli¹  Patrizia Casalini²  Piera Mondellini³  Dario Caccia³  Italia Bongarzone³  Francesca Miccichè³ 

[1] Department of Experimental Oncology and Molecular Medicine, Molecular Pharmacology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy;Department of Experimental Oncology and Molecular Medicine, Molecular Targeting Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy;Department of Experimental Oncology and Molecular Medicine, Proteomics Laboratory, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy;

关键词: Epidermal Growth Factor Receptor;    Papillary Thyroid Carcinoma;    Focal Adhesion Kinase;    Dasatinib;    Paxillin;   

DOI  :  10.1186/1476-4598-9-278

 received in 2010-05-10, accepted in 2010-10-18,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundTPC-1 is a papillary thyroid carcinoma (PTC)-derived cell line that spontaneously expresses the oncogene RET/PTC1. TPC-1 treated with the RET/PTC1 inhibitor RPI-1 displayed a cytostatic and reversible inhibition of cell proliferation and a strong activation of focal adhesion kinase (FAK). As dasatinib inhibition of Src results in reduction of FAK activation, we evaluated the effects of TPC-1 treatment with dasatinib in combination with RPI-1.ResultsDasatinib (100 nM) strongly reduced TPC-1 proliferation and induced marked changes in TPC-1 morphology. Cells appeared smaller and more contracted, with decreased cell spreading, due to the inhibition of phosphorylation of important cytoskeletal proteins (p130CAS, Crk, and paxillin) by dasatinib. The combination of RPI-1 with dasatinib demonstrated enhanced effects on cell proliferation (more than 80% reduction) and on the phosphotyrosine protein profile. In particular, RPI-1 reduced the phosphorylation of RET, MET, DCDB2, CTND1, and PLCγ, while dasatinib acted on the phosphorylation of EGFR, EPHA2, and DOK1. Moreover, dasatinib completely abrogated the phosphorylation of FAK at all tyrosine sites (Y576, Y577, Y861, Y925) with the exception of the autoactivation site (Y397). Notably, the pharmacological treatments induced an overexpression of integrin β1 (ITB1) that was correlated with a mild enhancement in phosphorylation of ERK1/2 and STAT3, known for their roles in prevention of apoptosis and in increase of proliferation and survival. A reduction in Akt, p38 and JNK1/2 activation was observed.ConclusionsAll data demonstrate that the combination of the two drugs effectively reduced cell proliferation (by more than 80%), significantly decreased Tyr phosphorylation of almost all phosphorylable proteins, and altered the morphology of the cells, supporting high cytostatic effects. Following the combined treatment, cell survival pathways appeared to be mediated by STAT3 and ERK activities resulting from integrin clustering and FAK autophosphorylation. EphA2 may also contribute, at least in part, to integrin and FAK activation. In conclusion, these data implicate ITB1 and EphA2 as promising therapeutic targets in PTC.

【 授权许可】

Unknown   
© Caccia et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.