scholarly journals Sequence dependence of cell growth inhibition by EGFR-tyrosine kinase inhibitor ZD1839, docetaxel, and cisplatin in head and neck cancer

Head & Neck ◽  
2009 ◽  
Vol 31 (10) ◽  
pp. 1263-1273 ◽  
Author(s):  
Carmen M. Klass ◽  
Mi Sun Choe ◽  
Selwyn J. Hurwitz ◽  
Mourad Tighiouart ◽  
Xin Zhang ◽  
...  
Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4460-4460
Author(s):  
Seiichi Okabe ◽  
Tetsuzo Tauchi ◽  
Eishi Ashihara ◽  
Shinya Kimura ◽  
Taira Maekawa ◽  
...  

Abstract Abstract 4460 The clinical use of imatinib, a specific BCR-ABL tyrosine kinase inhibitor (TKI) is effective in inducing a complete hematological and cytogenetic remission in a high percentage of chronic myeloid leukemia (CML) and Philadelphia chromosome (Ph) positive acute lymphoblastic leukemia (ALL) patients. However, imatinib does not efficiently kill leukemic stem cells and is limited by the emergence of resistance due to the point mutations in the BCR-ABL kinase domain. Histone acetyltransferases (HAT) and histone deacetylases (HDAC) control the acetylation of histones and intracellular proteins, and regulate the transcription and function of the proteins. HDAC inhibitor is a structurally diverse class of targeted anti-cancer agent. One of the pan-HDAC inhibitor, vorinostat (suberoylanilide hydroxamic acid: SAHA) is a small-molecule inhibitor of most human class I and class II HDAC, and is reported the efficacy of malignant cells including lymphomas and myeloid malignancies.Therefore, combination therapy using a BCR-ABL tyrosine kinase inhibitor and an HDAC inhibitor, vorinostat may help prevent CML relapse due to BCR-ABL point mutation and may improve their long-term outcome. In this study, we investigated the efficacy of vorinostat by using the Ph-positive leukemia cell line, K562 and Ba/F3 BCR-ABL cell in a random mutagenesis study for BCR-ABL mutation. We first performed a comprehensive drug combination experiment using vorinostat and BCR-ABL tyrosine kinase inhibitor, imatinib or nilotinib. The treatment of imatinib or nilotinib exhibits cell growth inhibition partially against Ba/F3 BCR-ABL cell in a random mutagenesis. We also found the BCR-ABL point mutation such as T315I or M344V after 2 weeks nilotinib treatment by direct sequence analysis. We show that vorinostat potently induced cell growth inhibition of K562 and Ba/F3 BCR-ABL cells in a random mutagenesis in a dose dependent manner. Combined treatment of Ba/F3 BCR-ABL cell in a random mutagenesis with vorinostat and nilotinib or imatinib caused significantly more cytotoxicity than each drug alone by colony assay. We investigated the intracellular signaling of vorinostat. Phosphorylation of BCR-ABL, Crk-L were reduced after vorinostat treatment for 24 hours in a dose dependent manner. Caspase 3 and poly (ADP-ribose) polymerase (PARP) activation were increased after vorinostat treatment. Vorinostat potently enhanced cell growth inhibition of Ba/F3 BCR-ABL point mutants (G250E, Q252H, Y253F, E255K, M294V, T315I, T315A, F317L, F317V, M351T and H396P) compared with Ba/F3 expressing Wt BCR-ABL cells. The protein level of BCR-ABL was reduced after vorinostat treatment. BCR-ABL degradations in BCR-ABL mutant cells were significantly enhanced compared with Ba/F3 Wt BCR-ABL cells. Although long term culture of Ba/F3 BCR-ABL cell in a random mutagenesis with 2μ M vorinostat significantly decreased cell growth, the cells were increased after removal of vorinostat. We found these cells were wild type BCR-ABL by direct sequence analysis. Data from this study suggested that administration of the vorinostat may mediate its effects on BCR-ABL positive cells included BCR-ABL point mutation and enhance cytotoxic effects of nilotinib or imatinib in BCR-ABL mutant cells, and provide information of potential therapeutic relevance. Disclosures: Ohyashiki: Nippon Shinyaku Co., Ltd.: Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3693-3693
Author(s):  
Seiichi Okabe ◽  
Tetsuzo Tauchi ◽  
Yuko Tanaka ◽  
Juri Sakuta ◽  
Kazuma Ohyashiki

Abstract Introduction: Chronic myeloid leukemia (CML) is characterized by the t(9:22) translocation known as the Philadelphia chromosome (Ph). ABL tyrosine kinase inhibitor (TKI), imatinib and second-generation ABL TKIs, nilotinib and dasatinib have demonstrated the potency against CML patients. However, resistance to ABL TKI can develop in CML patients due to BCR-ABL point mutations. Moreover, ABL TKIs do not eliminate the leukemia stem cells (LSCs). Therefore, new approach against BCR-ABL mutant cells and LSCs may improve the outcome of Ph-positive leukemia patients. In eukaryotic cells, histone acetylation/deacetylation is important in transcriptional regulation. Chromatin acetylation is controlled by the opposing effects of two families of enzymes: histone acetyltransferases (HAT) and histone deacetylases (HDACs). Deregulation of HDAC activity may be a cause of malignant disease in humans. Phosphoinositide 3-kinase (PI3K) pathway also regulates cell metabolism, proliferation and survival. Furthermore, aberrant activation of PI3K signaling pathway has been shown to be important in initiation maintenance of human cancers. CUDC-907 is an oral inhibitor of class I PI3K as well as class I and II HDAC enzymes. CUDC-907 is currently being investigated in a pivotal phase 1 clinical trial against hematological malignancies such as malignant lymphoma. We suggested that CUDC-907 mediated inhibition PI3K and HDAC activity and in combination with ABL TKIs may abrogate the proliferation and survival of Ph-positive leukemia cells including T315I mutation and ABL TKI resistant. Materials and methods: In this study, we investigated the combination therapy with a CUDC-907 and an ABL TKIs (imatinib, nilotinib and ponatinib) by using the BCR-ABL positive cell line, K562, murine Ba/F3 cell line which was transfected with T315I mutant, nilotinib resistant K562 and ponatinib resistant Ba/F3 cells and primary samples. Results: The treatment of imatinib, nilotinib and ponatinib exhibits cell growth inhibition partially against K562 cells in the presence of feeder cell (HS-5). We found that mRNA of PI3K subunit is significantly increased after a co-culture with HS-5 in K562 and primary CD34 positive CML samples. 72 h treatment of CUDC-907 exhibits cell growth inhibition and induced apoptosis against K562 cells in a dose dependent manner. We examined the intracellular signaling after treatment of CUDC-907. Phosphorylation of JNK, histone acetylation and activity of caspase 3, poly (ADP-ribose) polymerase (PARP) was increased. Anti-apoptotic protein, Mcl-1 was decreased in a dose dependent. We next investigated the efficacy between imatinib and CUDC-907 by using these cell line. Combined treatment of K562 cells with imatinib and CUDC-907 caused significantly more cytotoxicity than each drug alone. Caspase activity was increased and Akt activity was reduced. Phosphorylation of BCR-ABL, Crk-L was reduced and cleaved PARP was increased after imatinib and CUDC-907 treatment. We investigated the CUDC-907 activity against T315I positive cells. CUDC-907 potently induced cell growth inhibition of Ba/F3 T315I cells in a dose dependent manner. Combined treatment of Ba/F3 T315I cells with ponatinib and CUDC-907 caused significantly more cytotoxicity than each drug alone. Caspase activity was increased and Akt activity was reduced after ponatinib and CUDC-907 treatment. To assess the activity of ponatinib and CUDC-907, we performed to test on tumor formation in mice. We injected nude mice subcutaneously with Ba/F3 T315I mutant cells. A dose of 20 mg/kg/day p.o of ponatinib and 30 mg/kg/day p.o of CUDC-907 inhibited tumor growth and reduced tumor volume compared with control mice. The treatments were well tolerated with no animal health concerns observed. We also found that the treatment of CUDC-907 exhibits cell growth inhibition against Ba/F3 ponatinib resistant cells, K562 nilotinib resistant cells, T315I mutant primary samples and CD34 positive CML samples. Conclusion: These results indicated that administration of the dual PI3K and HDAC inhibitor, CUDC-907 may be a powerful strategy against ABL TKI resistant cells including T315I mutation and enhance cytotoxic effects of ABL TKI against those Ph-positive leukemia cells. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4240-4240
Author(s):  
Lin Qiu ◽  
Xiao-dan Wang ◽  
Fang Ge ◽  
Xiu-li Wang ◽  
Bo-long Zhang ◽  
...  

Abstract Imatinib (IM) is a higherly effective targeted drug for CML. However, some CML patients, especially accelerated and blast crisis phase, often relapse due to drug resistance resulting from the emergence of IM-resistant point mutations within the BCR-ABL tyrosine kinase domain. This stimulates the development of new kinase inhibitors that are able to override resistance to IM. HHGV678 is a novel tyrosine kinase inhibitor and we employed IM-sensitive (K562 and 32Dp210) and resistant (K562R and fifteen 32Dp210 mutants) BCR-ABL+ cell lines to compare HHGV678 with IM on growth inhibition. In addition, synergistic effect of HHGV678 with IM was observed in 32Dp210 and 5 BCR-ABL mutants frequently observed in CML patients. MTT assay results showed that the estimated IC50 value of HHGV678 for K562 and 32Dp210 were 15.5 and 28-fold, for K562R and 15 BCR-ABL mutants, were 1.4–124.0-fold lower than that of IM, indicating that HHGV678 was a more effective than IM against cell growth of IM-sensitive and resistant cells. Using combination index analysis, HHGV678 displayed synergistic growth inhibition when used with IM in BCR-ABL mutants (M244V, Q252H, Y253H, E255K and T315I). HHGV678, combined with IM at their IC50 concentration induced apoptosis 2–5 fold higher than that of HHGV678 alone in BCR-ABL mutants respectively, by annexin-V staining. At the same condition, HHGV6787 resulted in remarkable decrease in CrKL phosphorylation as determined by western blot. We conclude that HHGV678 have significant activity against IM-sensitive and resistant BCR-ABL+ cell, especially when it combined with IM that warrant further investigation in clinical trials.


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