RESUMO
The NTRK1 gene encodes Tropomyosin-related kinase A (TRKA), the high-affinity Nerve Growth Factor Receptor. NTRK1 was originally isolated from a colorectal carcinoma (CRC) sample as component of a somatic rearrangement (TPM3-NTRK1) resulting in expression of the oncogenic chimeric protein TPM3-TRKA, but there has been no subsequent report regarding the relevance of this oncogene in CRC. The KM12 human CRC cell line expresses the chimeric TPM3-TRKA protein and is hypersensitive to TRKA kinase inhibition. We report the detailed characterization of the TPM3-NTRK1 genomic rearrangement in KM12 cells and through a cellular screening approach, the identification of NMS-P626, a novel highly potent and selective TRKA inhibitor. NMS-P626 suppressed TPM3-TRKA phosphorylation and downstream signaling in KM12 cells and showed remarkable antitumor activity in mice bearing KM12 tumors. Finally, using quantitative reverse transcriptase PCR and immunohistochemistry (IHC) we identified the TPM3-NTRK1 rearrangement in a CRC clinical sample, therefore suggesting that this chromosomal translocation is indeed a low frequency recurring event in CRC and that such patients might benefit from therapy with TRKA kinase inhibitors.
Assuntos
Inibidores de Proteínas Quinases/farmacologia , Receptor trkA/antagonistas & inibidores , Receptor trkA/metabolismo , Tropomiosina/metabolismo , Animais , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Imunoprecipitação , Técnicas In Vitro , Camundongos , Ligação Proteica/efeitos dos fármacosRESUMO
Polo-like kinase 1 (PLK1) is the master regulator of mitosis and a target for anticancer therapy. To develop a marker of PLK1 activity in cells and tumour tissues, this study focused on translational controlled tumour protein (TCTP) and identified serine 46 as a site phosphorylated by PLK1 in vitro. Using an antibody raised against phospho-TCTP-Ser46, it was demonstrated that phosphorylation at this site correlates with PLK1 level and kinase activity in cells. Moreover, PLK1 depletion by siRNA or inactivation by specific inhibitors caused a correspondent decrease in phospho-TCTP-Ser46 signal validating this site as a direct marker of PLK1. Using this marker, the study characterized PLK1 inhibitors in cells by setting up a high-content assay and finally immunohistochemical assay suitable for following inhibitor activity in preclinical tumour models and possibly in clinical studies was developed.
Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Neoplasias Ósseas/enzimologia , Neoplasias Ósseas/metabolismo , Ciclo Celular/fisiologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Feminino , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Osteossarcoma/enzimologia , Osteossarcoma/metabolismo , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Proteína Tumoral 1 Controlada por Tradução , Quinase 1 Polo-LikeRESUMO
In this Letter is described the structure-based design of potent dihydro-pyrazoloquinazolines as PDK1 inhibitors. Starting from low potency HTS hits with the aid of X-ray crystallography and modeling, a medicinal chemistry activity was carried out to improve potency versus PDK1 and selectivity versus CDK2 protein kinase.
