RESUMEN
Selective inhibitors of the protein tyrosine phosphatase SHP2 (src homology regionâ 2 domain phosphatase; PTPN11), an enzyme that is deregulated in numerous human tumors, were generated through a combination of chemical synthesis and structure-based rational design. Seventy pyridazolon-4-ylidenehydrazinyl benzenesulfonates were prepared and evaluated in enzyme assays. The binding modes of active inhibitors were simulated in silico using a newly generated crystal structure of SHP2. The most powerful compound, GS-493 (4-{(2Z)-2-[1,3-bis(4-nitrophenyl)-5-oxo-1,5-dihydro-4H-pyrazol-4-yliden]hydrazino}benzenesulfonic acid; 25) inhibited SHP2 with an IC50 value of 71±15â nM in the enzyme assay and was 29- and 45-fold more active toward SHP2 than against related SHP1 and PTP1B. In cell culture experiments compound 25 was found to block hepatocyte growth factor (HGF)-stimulated epithelial-mesenchymal transition of human pancreatic adenocarcinoma (HPAF) cells, as indicated by a decrease in the minimum neighbor distances of cells. Moreover, 25 inhibited cell colony formation in the non-small-cell lung cancer cell line LXFAâ 526L in soft agar. Finally, 25 was observed to inhibit tumor growth in a murine xenograft model. Therefore, the novel specific compound 25 strengthens the hypothesis that SHP2 is a relevant protein target for the inhibition of mobility and invasiveness of cancer cells.
Asunto(s)
Antineoplásicos/farmacología , Movimiento Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Neoplasias/enzimología , Neoplasias/patología , Proteína Tirosina Fosfatasa no Receptora Tipo 11/antagonistas & inhibidores , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Ratones , Ratones Desnudos , Simulación del Acoplamiento Molecular , Estructura Molecular , Neoplasias/tratamiento farmacológico , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Relación Estructura-Actividad , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
In this study, we have used techniques from cell biology, biochemistry, and genetics to investigate the role of the tyrosine phosphatase Shp2 in tumor cells of MMTV-PyMT mouse mammary glands. Genetic ablation or pharmacological inhibition of Shp2 induces senescence, as determined by the activation of senescence-associated ß-gal (SA-ß-gal), cyclin-dependent kinase inhibitor 1B (p27), p53, and histone 3 trimethylated lysine 9 (H3K9me3). Senescence induction leads to the inhibition of self-renewal of tumor cells and blockage of tumor formation and growth. A signaling cascade was identified that acts downstream of Shp2 to counter senescence: Src, focal adhesion kinase, and Map kinase inhibit senescence by activating the expression of S-phase kinase-associated protein 2 (Skp2), Aurora kinase A (Aurka), and the Notch ligand Delta-like 1 (Dll1), which block p27 and p53. Remarkably, the expression of Shp2 and of selected target genes predicts human breast cancer outcome. We conclude that therapies, which rely on senescence induction by inhibiting Shp2 or controlling its target gene products, may be useful in blocking breast cancer.
Asunto(s)
Senescencia Celular , Neoplasias Mamarias Animales/enzimología , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Animales , Aurora Quinasa A/genética , Aurora Quinasa A/metabolismo , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Proteínas de Unión al Calcio , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Femenino , Histonas , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Neoplasias Mamarias Animales/genética , Neoplasias Mamarias Animales/patología , Metilación , Ratones , Ratones Transgénicos , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , Proteínas Quinasas Asociadas a Fase-S/genética , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
The protein tyrosine phosphatase Shp2 is a positive regulator of growth factor signaling. Gain-of-function mutations in several types of leukemia define Shp2 as a bona fide oncogene. We performed a high-throughput in silico screen for small-molecular-weight compounds that bind the catalytic site of Shp2. We have identified the phenylhydrazonopyrazolone sulfonate PHPS1 as a potent and cell-permeable inhibitor, which is specific for Shp2 over the closely related tyrosine phosphatases Shp1 and PTP1B. PHPS1 inhibits Shp2-dependent cellular events such as hepatocyte growth factor/scatter factor (HGF/SF)-induced epithelial cell scattering and branching morphogenesis. PHPS1 also blocks Shp2-dependent downstream signaling, namely HGF/SF-induced sustained phosphorylation of the Erk1/2 MAP kinases and dephosphorylation of paxillin. Furthermore, PHPS1 efficiently inhibits activation of Erk1/2 by the leukemia-associated Shp2 mutant, Shp2-E76K, and blocks the anchorage-independent growth of a variety of human tumor cell lines. The PHPS compound class is therefore suitable for further development of therapeutics for the treatment of Shp2-dependent diseases.