ABSTRACT
PURPOSE: The presence of TNF-α in approximately 50% of surgically resected tumors suggests that the canonical NF-κB and the mTOR pathways are activated. Inhibitor of IκB kinase ß (IKKß) acts as the signaling node that regulates transcription via the p-IκBα/NF-κB axis and regulates translation via the mTOR/p-S6K/p-eIF4EBP axis. A kinome screen identified a quinoxaline urea analog 13-197 as an IKKß inhibitor. We hypothesized that targeting the NF-κB and mTOR pathways with 13-197 will be effective in malignancies driven by these pathways. EXPERIMENTAL DESIGN: Retrospective clinical and preclinical studies in pancreas cancers have implicated NF-κB. We examined the effects of 13-197 on the downstream targets of the NF-κB and mTOR pathways in pancreatic cancer cells, pharmacokinetics, toxicity and tumor growth, and metastases in vivo. RESULTS: 13-197 inhibited the kinase activity of IKKß in vitro and TNF-α-mediated NF-κB transcription in cells with low-µmol/L potency. 13-197 inhibited the phosphorylation of IκBα, S6K, and eIF4EBP, induced G1 arrest, and downregulated the expression of antiapoptotic proteins in pancreatic cancer cells. Prolonged administration of 13-197 did not induce granulocytosis and protected mice from lipopolysaccharide (LPS)-induced death. Results also show that 13-197 is orally available with extensive distribution to peripheral tissues and inhibited tumor growth and metastasis in an orthotopic pancreatic cancer model without any detectable toxicity. CONCLUSION: These results suggest that 13-197 targets IKKß and thereby inhibits mTOR and NF-κB pathways. Oral availability along with in vivo efficacy without obvious toxicities makes this quinoxaline urea chemotype a viable cancer therapeutic.
Subject(s)
Antineoplastic Agents/pharmacology , I-kappa B Kinase/antagonists & inhibitors , NF-kappa B/metabolism , Pancreatic Neoplasms/drug therapy , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Apoptosis Regulatory Proteins/metabolism , Area Under Curve , Blotting, Western , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , G1 Phase Cell Cycle Checkpoints/drug effects , Humans , I-kappa B Kinase/metabolism , Immunohistochemistry , Mice , Mice, Inbred BALB C , Mice, Nude , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Phenylurea Compounds/chemistry , Phenylurea Compounds/pharmacokinetics , Phenylurea Compounds/pharmacology , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Quinoxalines/chemistry , Quinoxalines/pharmacokinetics , Quinoxalines/pharmacology , Tumor Burden/drug effects , Xenograft Model Antitumor AssaysABSTRACT
In HeLa cells the combinatorial knockdown of Bcl-xL and Mcl-1 is sufficient to induce spontaneous apoptosis. Quinoxaline derivatives were screened for the induction of Mcl-1 dependent apoptosis using a cell line without functional Bcl-xL. Quinoxaline urea analog 1 h was able to specifically induce apoptosis in an Mcl-1 dependent manner. We demonstrate that even small changes to 1h results in dramatic loss of activity. In addition, 1 h and ABT-737 synergistically inhibit cell growth and induce apoptosis. Our results also suggest that 1h could have therapeutic potential against ABT-737 refractory cancer.
Subject(s)
Quinoxalines/chemistry , Apoptosis/drug effects , Biphenyl Compounds/pharmacology , HeLa Cells , Humans , Myeloid Cell Leukemia Sequence 1 Protein , Nitrophenols/pharmacology , Piperazines/pharmacology , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Quinoxalines/chemical synthesis , Quinoxalines/pharmacology , Structure-Activity Relationship , Sulfonamides/pharmacology , bcl-X Protein/antagonists & inhibitors , bcl-X Protein/genetics , bcl-X Protein/metabolismABSTRACT
The macrocyclic diarylether heptanoid (MDEH) natural products have been used in folk medicine for centuries. MDEHs are reported to exert anti-tumor properties by inhibiting the activation of NF-κB. Here we report the synthesis of a small MDEH library (first reported synthesis of racemic platycarynol) using a Grubbs cross metathesis/Ullmann cyclization strategy. Evaluation of the library led to the identification of MDEH 9b which sensitizes pancreatic cancer cells to gemcitabine mediated growth inhibition and apoptosis.
Subject(s)
Ether/analogs & derivatives , Pancreatic Neoplasms/drug therapy , Antineoplastic Agents/pharmacology , Apoptosis , Biological Products/chemistry , Biological Products/pharmacology , Cell Line , Chemistry, Pharmaceutical/methods , Drug Design , HEK293 Cells , Humans , Models, Chemical , NF-kappa B/metabolism , Time Factors , Tumor Necrosis Factor-alpha/metabolismABSTRACT
The quinoxaline core is considered a privileged scaffold as it is found in a variety of biologically relevant molecules. Here we report the synthesis of a quinoxalin-6-amine library, screening against a panel of cancer cell lines and a structure-activity relationship (SAR). This resulted in the identification of a bisfuranylquinoxalineurea analog (7c) that has low micromolar potency against the panel of cancer cell lines. We also show that cells treated with quinoxalineurea 7c results in caspase 3/7 activation, PARP cleavage and Mcl-1 dependent apoptosis.