(5-(2-4-bis((3s)-3-methylmorpholin-4-yl)pyrido(2-3-d)pyrimidin-7-yl)-2-methoxyphenyl)methanol and Lung-Neoplasms

mTOR complex 1 (mTORC1) positively regulates cell invasion and metastasis by enhancing translation of Snail. A connection between mTOR complex 2 (mTORC2) and cell invasion and metastasis has also been suggested, yet the underlying biology or mechanism is largely unknown and thus is the focus of this study. Inhibition of mTOR with both mTOR inhibitors and knockdown of key components of mTORC, including rictor, Sin1, and raptor, decreased Snail protein levels. Inhibition of mTOR enhanced the rate of Snail degradation, which could be rescued by inhibition of the proteasome. Critically, inhibition of mTORC2 (by knocking down rictor) but not mTORC1 (by knocking down raptor) enhanced Snail degradation. Therefore, only mTORC2 inhibition induces Snail proteasomal degradation, resulting in eventual Snail reduction. Interestingly, inhibition of GSK3 but not SCF/β-TrCP rescued the Snail reduction induced by mTOR inhibitors, suggesting GSK3-dependent, but SCF/β-TrCP-independent proteasomal degradation of Snail. Accordingly, mTOR inhibitors elevated E-cadherin levels and suppressed cancer cell migration and invasion

Topics: Adaptor Proteins, Signal Transducing; Animals; Benzoxazoles; Breast Neoplasms; Carrier Proteins; Cell Line, Tumor; Female; Gene Knockdown Techniques; Glycogen Synthase Kinase 3; Humans; Lung Neoplasms; Mechanistic Target of Rapamycin Complex 2; Mice; Mice, Transgenic; Morpholines; Neoplasm Invasiveness; Neoplasm Metastasis; Protein Kinase Inhibitors; Pyrimidines; Rapamycin-Insensitive Companion of mTOR Protein; Snail Family Transcription Factors; TOR Serine-Threonine Kinases

ATP-competitive mTOR inhibitors have been studied as potential antitumor agents. Based on the structure-activity relationship of known mTOR inhibitors, a series of novel imidazo[1,2-b]pyridazine derivatives were synthesized and characterized. The anti-proliferative activities of these compounds were evaluated by SRB assay against six human cancer cell lines. Imidazo[1,2-b]pyridazine diaryl urea derivatives A15-A24 exhibited significant anti-proliferative activity especially against non-small cell lung cancer A549 and H460 with IC

Topics: A549 Cells; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Drug Design; Drug Screening Assays, Antitumor; Heterografts; Humans; Lung Neoplasms; Mice, Nude; Protein Kinase Inhibitors; Pyridazines; TOR Serine-Threonine Kinases

Kinase inhibitors are important cancer therapeutics. Polypharmacology is commonly observed, requiring thorough target deconvolution to understand drug mechanism of action. Using chemical proteomics, we analyzed the target spectrum of 243 clinically evaluated kinase drugs. The data revealed previously unknown targets for established drugs, offered a perspective on the "druggable" kinome, highlighted (non)kinase off-targets, and suggested potential therapeutic applications. Integration of phosphoproteomic data refined drug-affected pathways, identified response markers, and strengthened rationale for combination treatments. We exemplify translational value by discovering SIK2 (salt-inducible kinase 2) inhibitors that modulate cytokine production in primary cells, by identifying drugs against the lung cancer survival marker MELK (maternal embryonic leucine zipper kinase), and by repurposing cabozantinib to treat FLT3-ITD-positive acute myeloid leukemia. This resource, available via the ProteomicsDB database, should facilitate basic, clinical, and drug discovery research and aid clinical decision-making.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cytokines; Drug Discovery; fms-Like Tyrosine Kinase 3; Humans; Leukemia, Myeloid, Acute; Lung Neoplasms; Mice; Molecular Targeted Therapy; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proteomics; Xenograft Model Antitumor Assays

Small cell lung cancer (SCLC) is an aggressive cancer that represents ~15% of all lung cancers. Currently there are no targeted therapies to treat SCLC. Our genomic analysis of a metastatic SCLC cohort identified recurrent RICTOR amplification. Here, we examine the translational potential of this observation. RICTOR was the most frequently amplified gene observed (~14% patients), and co-amplified with FGF10 and IL7R on chromosome 5p13. RICTOR copy number variation correlated with RICTOR protein expression in SCLC cells. In parallel, cells with RICTOR copy number (CN) gain showed increased sensitivity to three mTOR inhibitors, AZD8055, AZD2014 and INK128 in cell growth assays, with AZD2014 demonstrating the best inhibition of downstream signaling. SCLC cells with RICTOR CN gain also migrated more rapidly in chemotaxis and scratch wound assays and were again more sensitive to mTOR inhibitors. The overall survival in SCLC patients with RICTOR amplification was significantly decreased (p = 0.021). Taken together, our results suggest that SCLC patients with RICTOR amplification may constitute a clinically important subgroup because of their potential response to mTORC1/2 inhibitors.

Topics: Adult; Aged; Aged, 80 and over; Benzamides; Benzoxazoles; Female; Fibroblast Growth Factor 10; Gene Amplification; Humans; Interleukin-7 Receptor alpha Subunit; Lung Neoplasms; Male; Middle Aged; Molecular Targeted Therapy; Morpholines; Protein Kinase Inhibitors; Pyrimidines; Rapamycin-Insensitive Companion of mTOR Protein; Small Cell Lung Carcinoma; Survival Analysis; Treatment Outcome

BH3 mimetics such as ABT-263 induce apoptosis in a subset of cancer models. However, these drugs have shown limited clinical efficacy as single agents in small-cell lung cancer (SCLC) and other solid tumor malignancies, and rational combination strategies remain underexplored. To develop a novel therapeutic approach, we examined the efficacy of ABT-263 across >500 cancer cell lines, including 311 for which we had matched expression data for select genes. We found that high expression of the proapoptotic gene Bcl2-interacting mediator of cell death (BIM) predicts sensitivity to ABT-263. In particular, SCLC cell lines possessed greater BIM transcript levels than most other solid tumors and are among the most sensitive to ABT-263. However, a subset of relatively resistant SCLC cell lines has concomitant high expression of the antiapoptotic myeloid cell leukemia 1 (MCL-1). Whereas ABT-263 released BIM from complexes with BCL-2 and BCL-XL, high expression of MCL-1 sequestered BIM released from BCL-2 and BCL-XL, thereby abrogating apoptosis. We found that SCLCs were sensitized to ABT-263 via TORC1/2 inhibition, which led to reduced MCL-1 protein levels, thereby facilitating BIM-mediated apoptosis. AZD8055 and ABT-263 together induced marked apoptosis in vitro, as well as tumor regressions in multiple SCLC xenograft models. In a Tp53; Rb1 deletion genetically engineered mouse model of SCLC, the combination of ABT-263 and AZD8055 significantly repressed tumor growth and induced tumor regressions compared with either drug alone. Furthermore, in a SCLC patient-derived xenograft model that was resistant to ABT-263 alone, the addition of AZD8055 induced potent tumor regression. Therefore, addition of a TORC1/2 inhibitor offers a therapeutic strategy to markedly improve ABT-263 activity in SCLC.

Topics: Aniline Compounds; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Cell Line, Tumor; Dose-Response Relationship, Drug; Genetic Engineering; Humans; Inhibitory Concentration 50; Lung Neoplasms; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Membrane Proteins; Mice; Morpholines; Multiprotein Complexes; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins; Remission Induction; Small Cell Lung Carcinoma; Sulfonamides; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

The mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/AKT signaling pathways interact at multiple nodes in cancer, including at mTOR complexes, suggesting an increased likelihood of redundancy and innate resistance to any therapeutic effects of single pathway inhibition. In this study, we investigated the therapeutic effects of combining the MAPK extracellular signal-regulated kinase (MEK)1/2 inhibitor selumetinib (AZD6244) with the dual mTORC1 and mTORC2 inhibitor (AZD8055). Concurrent dosing in nude mouse xenograft models of human lung adenocarcinoma (non-small cell lung cancers) and colorectal carcinoma was well tolerated and produced increased antitumor efficacy relative to the respective monotherapies. Pharmacodynamic analysis documented reciprocal pathway inhibition associated with increased apoptosis and Bim expression in tumor tissue from the combination group, where key genes such as DUSP6 that are under MEK functional control were also modulated. Our work offers a strong rationale to combine selumetinib and AZD8055 in clinical trials as an attractive therapeutic strategy.

Topics: Animals; Apoptosis; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Colorectal Neoplasms; Female; Gene Expression Profiling; Humans; Lung Neoplasms; MAP Kinase Signaling System; Mice; Mitogen-Activated Protein Kinase Kinases; Morpholines; Mutation; Neoplasms, Experimental; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Signal Transduction; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays