作者: Pinkerton, Anthony B ; Lee, J Scott ; Fruman, David A ; Schneider, Robert J ; Walters, Beth ; Fung, Amos ; Jackson, Michael R ; Li, Boyang ; Chiu, Honyin ; Ronai, Ze'ev A ; Mallya, Sharmila ; Nguyen, Nancy ; Herzog, Lee-Or ; Buono, Roberta

AbstractBackgroundThe BCL2 inhibitor venetoclax has shown efficacy in several hematologic malignancies, with the greatest response rates in indolent blood cancers such as chronic lymphocytic leukaemia. There is a lower response rate to venetoclax monotherapy in diffuse large B-cell lymphoma (DLBCL).MethodsWe tested inhibitors of cap-dependent mRNA translation for the ability to sensitise DLBCL and mantle cell lymphoma (MCL) cells to apoptosis by venetoclax. We compared the mTOR kinase inhibitor (TOR-KI) MLN0128 with SBI-756, a compound targeting eukaryotic translation initiation factor 4G1 (eIF4G1), a scaffolding protein in the eIF4F complex.ResultsTreatment of DLBCL and MCL cells with SBI-756 synergised with venetoclax to induce apoptosis in vitro, and enhanced venetoclax efficacy in vivo. SBI-756 prevented eIF4E-eIF4G1 association and cap-dependent translation without affecting mTOR substrate phosphorylation. In TOR-KI-resistant DLBCL cells lacking eIF4E binding protein-1, SBI-756 still sensitised to venetoclax. SBI-756 selectively reduced translation of mRNAs encoding ribosomal proteins and translation factors, leading to a reduction in protein synthesis rates in sensitive cells. When normal lymphocytes were treated with SBI-756, only B cells had reduced viability, and this correlated with reduced protein synthesis.ConclusionsOur data highlight a novel combination for treatment of aggressive lymphomas, and establishes its efficacy and selectivity using preclinical models.

2015-12-15·Cancer Research1区 · 医学

SBI-0640756 Attenuates the Growth of Clinically Unresponsive Melanomas by Disrupting the eIF4F Translation Initiation Complex

1区 · 医学

Article

作者: Pellecchia, Maurizio ; Feng, Yongmei ; Li, Jian-Liang ; Zhang, Tongwu ; Ronai, Ze'ev A. ; Barile, Elisa ; Davies, Michael A. ; Bosenberg, Marcus ; Hassig, Christian A. ; Grotegut, Stefan ; Lau, Eric ; Hulea, Laura ; James, Brian ; De, Surya K. ; Topisirovic, Ivan ; Pinkerton, Anthony B. ; Brown, Kevin M. ; Kim, Hyungsoo ; Cheli, Yann ; Yin, Hongwei

AbstractDisrupting the eukaryotic translation initiation factor 4F (eIF4F) complex offers an appealing strategy to potentiate the effectiveness of existing cancer therapies and to overcome resistance to drugs such as BRAF inhibitors (BRAFi). Here, we identified and characterized the small molecule SBI-0640756 (SBI-756), a first-in-class inhibitor that targets eIF4G1 and disrupts the eIF4F complex. SBI-756 impaired the eIF4F complex assembly independently of mTOR and attenuated growth of BRAF-resistant and BRAF-independent melanomas. SBI-756 also suppressed AKT and NF-κB signaling, but small-molecule derivatives were identified that only marginally affected these pathways while still inhibiting eIF4F complex formation and melanoma growth, illustrating the potential for further structural and functional manipulation of SBI-756 as a drug lead. In the gene expression signature patterns elicited by SBI-756, DNA damage, and cell-cycle regulatory factors were prominent, with mutations in melanoma cells affecting these pathways conferring drug resistance. SBI-756 inhibited the growth of NRAS, BRAF, and NF1-mutant melanomas in vitro and delayed the onset and reduced the incidence of Nras/Ink4a melanomas in vivo. Furthermore, combining SBI-756 and a BRAFi attenuated the formation of BRAFi-resistant human tumors. Taken together, our findings show how SBI-756 abrogates the growth of BRAF-independent and BRAFi-resistant melanomas, offering a preclinical rationale to evaluate its antitumor effects in other cancers. Cancer Res; 75(24); 5211–8. ©2015 AACR.

Scientific Reports3区 · 综合性期刊

Targeting eIF4F translation complex sensitizes B-ALL cells to tyrosine kinase inhibition

3区 · 综合性期刊

ArticleOA

作者: Herzog, Lee-Or ; Thao, Joshua ; Duong, Madeleine R ; Lee, Jong-Hoon Scott ; Mallya, Sharmila ; Vo, Thanh-Trang ; Fruman, David A ; Buono, Roberta ; Gotesman, Moran

AbstractThe mechanistic target of rapamycin (mTOR) is a kinase whose activation is associated with poor prognosis in pre-B cell acute lymphoblastic leukemia (B-ALL). These and other findings have prompted diverse strategies for targeting mTOR signaling in B-ALL and other B-cell malignancies. In cellular models of Philadelphia Chromosome-positive (Ph+) B-ALL, mTOR kinase inhibitors (TOR-KIs) that inhibit both mTOR-complex-1 (mTORC1) and mTOR-complex-2 (mTORC2) enhance the cytotoxicity of tyrosine kinase inhibitors (TKIs) such as dasatinib. However, TOR-KIs have not shown substantial efficacy at tolerated doses in blood cancer clinical trials. Selective inhibition of mTORC1 or downstream effectors provides alternative strategies that may improve selectivity towards leukemia cells. Of particular interest is the eukaryotic initiation factor 4F (eIF4F) complex that mediates cap-dependent translation. Here we use novel chemical and genetic approaches to show that selective targeting of either mTORC1 kinase activity or components of the eIF4F complex sensitizes murine BCR-ABL-dependent pre-B leukemia cells to dasatinib. SBI-756, a small molecule inhibitor of eIF4F assembly, sensitizes human Ph+ and Ph-like B-ALL cells to dasatinib cytotoxicity without affecting survival of T lymphocytes or natural killer cells. These findings support the further evaluation of eIF4F-targeted molecules in combination therapies with TKIs in B-ALL and other blood cancers.

100 项与 SBI-0640756 相关的药物交易

登录后查看更多信息