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Antiproliferative and proapoptotic activity of GUT-70 mediated through potent inhibition of Hsp90 in mantle cell lymphoma

BACKGROUND: Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma with poor prognosis, requiring novel anticancer strategies. METHODS: Mantle cell lymphoma cell lines with known p53 status were treated with GUT-70, a tricyclic coumarin derived from Calophyllum brasiliense, and the biological a...

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Detalles Bibliográficos
Autores principales: Jin, L, Tabe, Y, Kimura, S, Zhou, Y, Kuroda, J, Asou, H, Inaba, T, Konopleva, M, Andreeff, M, Miida, T
Formato: Texto
Lenguaje:English
Publicado: Nature Publishing Group 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3039813/
https://www.ncbi.nlm.nih.gov/pubmed/21139584
http://dx.doi.org/10.1038/sj.bjc.6606007
Descripción
Sumario:BACKGROUND: Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma with poor prognosis, requiring novel anticancer strategies. METHODS: Mantle cell lymphoma cell lines with known p53 status were treated with GUT-70, a tricyclic coumarin derived from Calophyllum brasiliense, and the biological and biochemical consequences of GUT-70 were studied. RESULTS: GUT-70 markedly reduced cell proliferation/viability through G(1) cell cycle arrest and increased apoptosis, with greater sensitivity in mutant (mt)-p53-expressing MCL cells than in wild-type (wt)-p53-bearing cells. Mechanistically, GUT-70 showed binding affinity to heat-shock protein 90 (Hsp90) and ubiquitin-dependent proteasomal degradation of Hsp90 client proteins, including cyclin D1, Raf-1, Akt, and mt-p53. Depletion of constitutively overexpressed cyclin D1 by GUT-70 was accompanied by p27 accumulation and decreased Rb phosphorylation. GUT-70 induced mitochondrial apoptosis with Noxa upregulation and Mcl-1 downregulation in mt-p53 cells, but Mcl-1 accumulation in wt-p53 cells. Noxa and Mcl-1 were coimmunoprecipitated, and activated BAK. Treatment with a combination of GUT-70 and bortezomib or doxorubicin had synergistic antiproliferative effects in MCL cells that were independent of p53 status. CONCLUSION: GUT-70 has pronounced antiproliferative effects in MCL with mt-p53, a known negative prognostic factor for MCL, through Hsp90 inhibition. These findings suggest that GUT-70 has potential utility for the treatment of MCL.