Targeted inhibition of Src kinase with dasatinib blocks thyroid cancer growth and metastasis
Menée in vitro et in vivo, cette étude évalue l'efficacité du dasatinib, un inhibiteur de kinases de la famille Src, dans la réduction de la croissance tumorale et la prévention des métastases des cancers de la thyroïde
Purpose: There are no effective therapies for patients with poorly differentiated thyroid cancer (PTC) or anaplastic thyroid cancer (ATC), and metastasis to the bone represents a significantly worse prognosis. Src Family Kinases (SFKs) are overexpressed and activated in numerous tumor types and have emerged as a promising therapeutic target, especially in relation to metastasis. We recently showed that Src is overexpressed and activated in thyroid cancer. We therefore tested whether inhibition of Src with dasatinib (BMS-354825) blocks thyroid cancer growth and metastasis. Experimental Design: The effects of dasatinib on thyroid cancer growth, signaling, cell cycle, and apoptosis was evaluated in vitro. The therapeutic efficacy of dasatinib was further tested in in vivo using an orthotopic and a novel experimental metastasis model. Expression and activation of SFKs in thyroid cancer cells was characterized, and selectivity of dasatinib was determined using a Src-gatekeeper mutant. Results: Dasatinib treatment inhibited Src signaling, decreased growth, and induced cell cycle arrest and apoptosis in a subset of thyroid cancer cells. Immunoblotting showed that c-Src and Lyn are expressed in thyroid cancer cells, and that c-Src is the predominant SFK activated. Treatment with dasatinib blocked PTC tumor growth in an orthotopic model by > 90% (p=0.0014). Adjuvant and post-treatment approaches with dasatinib significantly inhibited metastasis (p=0.016 and p=0.004, respectively). Conclusion: These data provide the first evidence that Src is a central mediator of thyroid cancer growth and metastasis, indicating that Src inhibitors may have a higher therapeutic efficacy in thyroid cancer, as both anti-tumor and anti-metastatic agents.