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Targeting aurora kinases with danusertib (PHA-739358) inhibits growth of liver metastases from gastroenteropancreatic neuroendocrine tumors in an orthotopic xenograft model.

I. Medizinische Klinik, Diagnostische und Interventionelle Radiologie, II. Medizinische Klinik, Onkologisches Zentrum, Universitätsklinikum Hamburg-Eppendorf; Labor Lademannbogen, Hamburg, Germany.
Clinical Cancer Research (Impact Factor: 7.84). 07/2012; 18(17):4621-32. DOI: 10.1158/1078-0432.CCR-11-2968
Source: PubMed

ABSTRACT Aurora kinases play a crucial role in cell-cycle control. Uncontrolled expression of aurora kinases causes aneuploidy and tumor growth. As conservative treatment options for advanced gastroenteropancreatic neuroendocrine tumors (GEP-NET) are disappointing, aurora kinases may be an interesting target for novel therapeutic strategies.
Human GEP-NETs were tested for aurora kinase expression. The efficacy of the new aurora kinase inhibitor danusertib was evaluated in two human GEP-NET cell lines (BON1 and QGP) in vitro and in vivo.
The majority of ten insulinomas and all 33 nonfunctional pancreatic or midgut GEP-NETs expressed aurora A despite a mostly high degree of cell differentiation. Both human GEP-NET cell lines expressed aurora kinase A and B, and high Ser10 phosphorylation of histone H3 revealed increased aurora B activity. Remarkably, danusertib led to cell-cycle arrest and completely inhibited cell proliferation of the GEP-NET cells in vitro. Decreased phosphorylation of histone H3 indicated effective aurora B inhibition. In a subcutaneous murine xenograft model, danusertib significantly reduced tumor growth in vivo compared with controls or mice treated with streptozotocine/5-fluorouracil. As a consequence, decreased levels of tumor marker chromogranin A were found in mouse serum samples. In a newly developed orthotopic model for GEP-NET liver metastases by intrasplenic tumor cell transplantation, dynamic MRI proved significant growth inhibition of BON1- and QGP-derived liver metastases.
These results show that danusertib may impose a new therapeutic strategy for aurora kinase expressing metastasized GEP-NETs.

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