Search

mTOR is an atypical serine threonine kinase involved in regulating major cellular functions, such as nutrients sensing, growth, and proliferation. mTOR is part of the multiprotein complexes mTORC1 and mTORC2, which have been shown to play critical yet functionally distinct roles in the regulation of cellular processes. Current clinical mTOR inhibitors only inhibit the mTORC1 complex and are derivatives of the macrolide rapamycin (rapalogs). Encouraging effects have been observed with rapalogs in estrogen receptor–positive (ER+) breast cancer patients in combination with endocrine therapy, such as aromatase inhibitors. AZD2014 is a small-molecule ATP competitive inhibitor of mTOR that inhibits both mTORC1 and mTORC2 complexes and has a greater inhibitory function against mTORC1 than the clinically approved rapalogs. Here, we demonstrate that AZD2014 has broad antiproliferative effects across multiple cell lines, including ER+ breast models with acquired resistance to hormonal therapy and cell lines with acquired resistance to rapalogs. In vivo, AZD2014 induces dose-dependent tumor growth inhibition in several xenograft and primary explant models. The antitumor activity of AZD2014 is associated with modulation of both mTORC1 and mTORC2 substrates, consistent with its mechanism of action. In combination with fulvestrant, AZD2014 induces tumor regressions when dosed continuously or using intermittent dosing schedules. The ability to dose AZD2014 intermittently, together with its ability to block signaling from both mTORC1 and mTORC2 complexes, makes this compound an ideal candidate for combining with endocrine therapies in the clinic. AZD2014 is currently in phase II clinical trials. Mol Cancer Ther; 14(11); 2508–18. ©2015 AACR.

Purpose: KRAS wild-type status is an imperfect predictor of sensitivity to anti-EGF receptor (EGFR) monoclonal antibodies in colorectal cancer, motivating efforts to identify novel molecular aberrations driving RAS. This study aimed to build a quantitative readout of RAS pathway activity to (i) uncover molecular surrogates of RAS activity specific to colorectal cancer, (ii) improve the prediction of cetuximab response in patients, and (iii) suggest new treatment strategies. Experimental Design: A model of RAS pathway activity was trained in a large colorectal cancer dataset and validated in three independent colorectal cancer patient datasets. Novel molecular traits were inferred from The Cancer Genome Atlas colorectal cancer data. The ability of the RAS model to predict resistance to cetuximab was tested in mouse xenografts and three independent patient cohorts. Drug sensitivity correlations between our model and large cell line compendiums were performed. Results: The performance of the RAS model was remarkably robust across three validation datasets. (i) Our model confirmed the heterogeneity of the RAS phenotype in KRAS wild-type patients, and suggests novel molecular traits driving its phenotype (e.g., MED12 loss, FBXW7 mutation, MAP2K4 mutation). (ii) It improved the prediction of response and progression-free survival (HR, 2.0; P < 0.01) to cetuximab compared with KRAS mutation (xenograft and patient cohorts). (iii) Our model consistently predicted sensitivity to MAP–ERK kinase (MEK) inhibitors (P < 0.01) in two cell panel screens. Conclusions: Modeling the RAS phenotype in colorectal cancer allows for the robust interrogation of RAS pathway activity across cell lines, xenografts, and patient cohorts. It demonstrates clinical utility in predicting response to anti-EGFR agents and MEK inhibitors. Clin Cancer Res; 20(1); 265–72. ©2013 AACR.

Mutant-selective EGFR tyrosine kinase inhibitors (TKI), such as osimertinib, are active agents for the treatment of EGFR-mutant lung cancer. Specifically, these agents can overcome the effects of the T790M mutation, which mediates resistance to first- and second-generation EGFR TKI, and recent clinical trials have documented their efficacy in patients with EGFR-mutant lung cancer. Despite promising results, therapeutic efficacy is limited by the development of acquired resistance. Here we report that Src family kinases (SFK) and focal adhesion kinase (FAK) sustain AKT and MAPK pathway signaling under continuous EGFR inhibition in osimertinib-sensitive cells. Inhibiting either the MAPK pathway or the AKT pathway enhanced the effects of osimertinib. Combined SFK/FAK inhibition exhibited the most potent effects on growth inhibition, induction of apoptosis, and delay of acquired resistance. SFK family member YES1 was amplified in osimertinib-resistant EGFR-mutant tumor cells, the effects of which were overcome by combined treatment with osimertinib and SFK inhibitors. In conclusion, our data suggest that the concomitant inhibition of both SFK/FAK and EGFR may be a promising therapeutic strategy for EGFR-mutant lung cancer. Cancer Res; 77(11); 2990–3000. ©2017 AACR.

Accurate variant calling in next generation sequencing (NGS) is critical to understand cancer genomes better. Here we present VarDict, a novel and versatile variant caller for both DNA- and RNA-sequencing data. VarDict simultaneously calls SNV, MNV, InDels, complex and structural variants, expanding the detected genetic driver landscape of tumors. It performs local realignments on the fly for more accurate allele frequency estimation. VarDict performance scales linearly to sequencing depth, enabling ultra-deep sequencing used to explore tumor evolution or detect tumor DNA circulating in blood. In addition, VarDict performs amplicon aware variant calling for polymerase chain reaction (PCR)-based targeted sequencing often used in diagnostic settings, and is able to detect PCR artifacts. Finally, VarDict also detects differences in somatic and loss of heterozygosity variants between paired samples. VarDict reprocessing of The Cancer Genome Atlas (TCGA) Lung Adenocarcinoma dataset called known driver mutations in KRAS, EGFR, BRAF, PIK3CA and MET in 16% more patients than previously published variant calls. We believe VarDict will greatly facilitate application of NGS in clinical cancer research.

The cyclin dependent kinase (CDK) –retinoblastoma (RB) -E2F pathway plays a critical role in the control of cell cycle in estrogen receptor positive (ER+) breast cancer. Small molecule inhibitors of CDK4/6 have shown promise in this tumour type in combination with hormonal therapies, reflecting the particular dependence of this subtype of cancer on cyclin D1 and E2F transcription factors. mTOR inhibitors have also shown potential in clinical trials in this disease setting. Recent data has suggested cooperation between the phosphatidylinositol 3-kinase (PI3K) pathway and CDK4/6 inhibition in preventing early adaptation and eliciting growth arrest, but the mechanisms of the interplay between these pathways have not been fully elucidated. Here we show that profound and durable inhibition of ER+ breast cancer growth is likely to require multiple hits on E2F mediated transcription. We demonstrate that inhibition of mTOR using the mTORC1/2 inhibitor vistusertib at 300nM causes a >50% decrease in cyclin D1 protein levels and RB phosphorylation in three cell lines. At these concentrations, vistusertib treatment also elicits marked effects on E2F mediated transcription, causing changes in the mRNA levels of 28 out of 43 (65%) of a selected set of E2F target genes.Combined inhibition of mTOR, CDK4/6 and ER delivers profound and durable regressions in breast cancer cell lines and xenografts (110.2% tumour growth inhibition at day 48). In vivo data show, that over a period of 58 days, tumours failed to re-grow in the presence of the triplet combination compared to either agent alone, suggesting, that the triplet is necessary to maintain growth inhibition. Furthermore, we show that CDK4/6 inhibitor resistant cell lines re-activate the CDK-RB-E2F pathway, but remain sensitive to mTOR inhibition (EC50 52.7 nM in parental cells vs 39.6-73.3 nM in a number of palbociclib resistant cell populations), suggesting that mTORC1/2 inhibitors may represent an option for patients that have relapsed on CDK4/6 therapy. A Phase I study (PASTOR) combining the dual TOR kinase inhibitor Vistusertib with Palbociclib, and Fulvestrant is underway to explore safety and efficacy of the triplet combination in patients with metastatic breast cancer. Citation Format: Oelmann E, Michaloglou C, Crafter C, Siersbaek R, Delpuech O, Curven J, Carnevalli L, Staniszweska A, Polanska U, Cheraghchi-Bashi A, Lawson M, Chernukhin I, McEwen R, Carroll J, Cosulich S. Combined inhibition of mTOR and CDK4/6 is required for optimal blockade of E2F function and long term growth inhibition in estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD4-04.

The PIK3CA gene, encoding the p110α catalytic unit of PI3Kα, is one of the most frequently mutated oncogenes in human cancer. Hence, PI3Kα is a target subject to intensive efforts in identifying inhibitors and evaluating their therapeutic potential. Here, we report studies with a novel PI3K inhibitor, AZD8835, currently in phase I clinical evaluation. AZD8835 is a potent inhibitor of PI3Kα and PI3Kδ with selectivity versus PI3Kβ, PI3Kγ, and other kinases that preferentially inhibited growth in cells with mutant PIK3CA status, such as in estrogen receptor–positive (ER+) breast cancer cell lines BT474, MCF7, and T47D (sub-μmol/L GI50s). Consistent with this, AZD8835 demonstrated antitumor efficacy in corresponding breast cancer xenograft models when dosed continuously. In addition, an alternative approach of intermittent high-dose scheduling (IHDS) was explored given our observations that higher exposures achieved greater pathway inhibition and induced apoptosis. Indeed, using IHDS, monotherapy AZD8835 was able to induce tumor xenograft regression. Furthermore, AZD8835 IHDS in combination with other targeted therapeutic agents further enhanced antitumor activity (up to 92% regression). Combination partners were prioritized on the basis of our mechanistic insights demonstrating signaling pathway cross-talk, with a focus on targeting interdependent ER and/or CDK4/6 pathways or alternatively a node (mTOR) in the PI3K-pathway, approaches with demonstrated clinical benefit in ER+ breast cancer patients. In summary, AZD8835 IHDS delivers strong antitumor efficacy in a range of combination settings and provides a promising alternative to continuous dosing to optimize the therapeutic index in patients. Such schedules merit clinical evaluation. Mol Cancer Ther; 15(5); 877–89. ©2016 AACR.

The increased usage of circulating tumor DNA (ctDNA) sequencing for oncology clinical research demonstrates a critical need for sensitive and specific testing. While we have observed a high degree of concordance between single tumor mutations in tumor and plasma, several recent studies have highlighted a lack of concordance between plasma and tumor panel NGS gene panel testing due to biological and technical factors. To explore further these factors and benchmark ctDNA NGS testing services, a set of matched plasma, tumor, and normal samples from 24 subjects were acquired from three biobanking companies. Replicate 2 ml-plasma samples were tested by four ctDNA sequencing companies, and matching tumor/normal samples were tested by two tumor sequencing companies. Concordance was measured by comparing plasma mutations to tumor mutations as well as comparing mutations among the same plasma tested by the ctDNA companies. While our experience with NGS of matched samples from clinical trials typically identifies ~30% of patients with no detectable mutation and therefore likely not shedding tumor DNA, with the retrospectively collected commercial samples ~60% lacked detectable high confidence mutations, likely due to quality control issues with sample collection. We also found variation in the concordance of ctDNA mutation detection rates among the four vendors, due to significant differences in DNA yield and assay sensitivity. While factors such as tumor heterogeneity and timing of plasma-tumor collection can lower concordance rates, the majority of discordance in our study was due to technical rather than biological variation. Assay analytical variance and the impact of reporting false positive variants are key factors that need to be addressed as plasma-based NGS testing is more widely incorporated into translational and clinical research. Examples illustrating the complexity of the analyses and giving support for confidence in ctDNA testing results will be given. Citation Format: Daniel Stetson, Brian Dougherty, Ambar Ahmed, Tristan Lubinski, Aleksandra Markovets, Kenneth Thress, Robert McEwen, Gaia Schiavon, David Whitston, Barrett Nuttall, J. Carl Barrett. Examination of analytical factors impacting concordance of plasma-tumor testing by next-generation sequencing (NGS) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-249. doi:10.1158/1538-7445.AM2017-LB-249

The efficiency and effectiveness of target selection and validation could be improved with accessible, standardized and integrated biological reference data sets. Such resources should be established through precompetitive approaches.

The PIK3CA gene, encoding the p110 catalytic unit of PI3Kα, is one of the most frequently mutated oncogenes described in human cancer. Hence PI3Kα is a target subject to intensive efforts in identifying inhibitors and evaluating their therapeutic potential. To date most studies with PI3K inhibitors have used a continuous (daily) dosing schedule and although clinical responses have been reported the overall activity observed has been moderate. This may in part be due to suboptimal pathway inhibition which is capped by normal tissue toxicities such as rash, diarrhoea and hyperglycaemia. Furthermore, additional dose reduction may be required when such agents are used in combination with other therapies. Therefore in our efforts to optimise inhibition of PI3K pathway signalling, we have explored high dose intermittent scheduling as an alternative to continuous dosing. Here we describe pre-clinical studies that exemplify such concepts, centred around use of AZD8835, a PI3K inhibitor currently in Phase 1 clinical evaluation. AZD8835 is a novel and potent inhibitor of PI3Kα and PI3Kδ, with selectivity vs. PI3Kβ, PI3Kγ(IC50s of 6nM, 6nM, 431nM and 90nM respectively in enzyme assays) and other kinases. AZD8835 preferentially displays activity in tumour models with a mutant PIK3CA background, such as ER+ve breast cancer models. Such models were used in our investigations, in both cell culture and in mouse xenograft contexts. We demonstrate that a high dose intermittent schedule of single agent AZD8835 achieves greater pathway inhibition yielding significant anti-tumour responses. In the sensitive BT474 xenograft model, a dose of 100mg/kg AZD8835 BID on days 1 and 4 in a weekly schedule delivered -36% tumour regression, accompanied by a strongly elevated rapid onset apoptosis signal with 4-16% cells staining positively for cleaved-caspase3. We also evaluated AZD8835 in combination with other targeted therapeutic agents, in MCF7, BT474 and T47D breast models, observing increased sensitivity relative to single agent AZD8835; firstly with agents that target other nodes in the PI3K pathway; secondly with agents targeting parallel but interconnected driver pathways in breast disease (ER, CDK4/6). Overall the data indicate that high dose intermittent scheduling can deliver strong anti-tumour efficacy in a range of combination settings and provides a promising alternative to continuous dosing. Such schedules merit clinical evaluation. Citation Format: Kevin Hudson, Urs Hancox, Cath Trigwell, Phillippa Dudley, Lyndsey Hanson, Robert McEwen, Alys Jones, Marie Cumberbatch, Urszula Polanska, Rebecca Ellston, Oona Delpuech, Pablo Morentin Gutierrez, Lara Ward, Francisco Cruzalegui, Stephen Green. High dose intermittent scheduling of AZD8835, a novel potent and selective inhibitor of PI3Kα and PI3Kδ, identifies potential treatment strategies for PIK3CA-dependent cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2665. doi:10.1158/1538-7445.AM2015-2665

There is a widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. In Europe, these requires are now being met by systems using large uncooled ferroelectric detector arrays offering performance levels which, until recently, could only be achieved by expensive cryogenically cooled systems. The uncooled technologies a result of collaboration between the UK Defence Evaluation and Research Agency (DERA) and Marconi Electronic Systems (MES) under a 'Dual Use Technology Program (DUTP). The successes from this program have resulted in developments for civil applications, including both hand held and helmet mounted fire-fighter's thermal imaging cameras. Military applications include personal surveillance sensors, vehicle driving aids, airborne flying aids and thermal weapon sighting systems. The products available to date have been based on hybrid ferroelectric detector technology in which the IR sensing material is manufactured separately from the silicon readout circuit to which it is subsequently bonded. Meanwhile, the ongoing DUTP program is developing a high performance 'integrated' detector technology in which the ferroelectric ceramic material is deposited as a microbridge structure directly onto the silicon readout circuit. The improved performance available from this approach will realize major enhancement and cost reductions to be achieved in future thermal imaging sensor developments.

There is widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. In Europe, these requirements are now being met by systems using large uncooled ferroelectric detector arrays offering performance levels which, until recently, could only be achieved by expensive cryogenically cooled systems. The uncooled technology is the result of collaboration between the UK Defence Research Agency (DRA) and GEC-Marconi Electro Optics (GMEO) under a 'dual use technology program' (DUTP). This has resulted in the design of an uncooled module suite which constitute the core elements of the European uncooled thermal imaging sensors. This module suite has been adopted by UK MoD to meet the requirements of the UK Stairs A demonstrator program producing a lightweight thermal surveillance and weapon sight. A European consortium including Delft Instruments and Signaal Usfa (DISU) in Holland have also adopted the modules to meet the requirements of the lightweight infrared observation nightsight (LION). This product is being marketed in collaboration with Thomson CSF Optronics, of France. This paper discusses the current status of the underlying detector and processing technology including enhancements already in development. In addition, the designs and benefits offered by the Stairs A and LION products are addressed.

AZD4547 is an orally bio-available, highly selective and potent small molecule inhibitor, ATP competitive inhibitor of FGF receptors 1, 2 and 3. To identify novel dynamic transcript biomarkers of FGFR signalling inhibition by AZD4547, a gene expression profiling study was performed. Cell lines defined as sensitive or resistant to AZD4547 (n=10 for each class) were treated with AZD4547 or DMSO control for 2, 6 or 24 hours and processed for microarray analysis. Amongst those genes modulated by AZD4547, the MEK signature genes DUSP6 and ETV5, together with the MAPK pathway regulator SPRED1 were repressed on AZD4547 treatment across all sensitive cell lines over time, consistent with FGFR signalling through this pathway. Further in vivo validation using three FGFR sensitive/responsive xenograft models (SNU16, KMS11, KG1a) was performed. We observed time dependent repression (16h to 24h) of DUSP6, ETV5 and SPRED1 across all three xenograft models which was consistent with plasma exposure of AZD4547 in vivo. In addition, modulation of these transcript biomarkers corresponded with inhibition of phosphorylation of FGFR, FRS2 and ERK, supporting engagement of the FGFR signalling pathway. Taken together, these data identify novel dynamic biomarkers of FGFR inhibition in vivo. Citation Format: Oona Delpuech, Claire Rooney, Lorraine Mooney, Robert McEwen, Sarah Fenton, Dawn Baker, Robert Shaw, Jonathan Dry, Elaine Kilgour, Paul Smith. Identification of novel dynamic biomarkers of FGFR inhibition by the FGFR1,2 and 3 selective inhibitor AZD4547. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 908. doi:10.1158/1538-7445.AM2013-908

There is a widespread requirement for wide area surveillance with target detection and recognition. To achieve the above aims with a single sensor is difficult and inevitably performance compromises have to be made. A system, designated Firefly, has been developed which splits the task of surveillance/target detection from that of recognition. Firefly uses separate sensors for both tasks, each sensor can then be optimized for the role it has to perform For surveillance and target detection, Firefly makes use of a previously developed scanned thermal imager operating in the 8 - 11 micrometer waveband. There was no suitable sensor available for the recognition role and so a 3 - 5 micrometer imager based on a 2D starring array was developed for this purpose. The Firefly system is described in this paper with emphasis being given to a description of the high resolution, recognition sensor where the development effort was concentrated. Results of performance also are given.

Large arrays of ferroelectric elements have considerable potential for thermal imaging applications, offering operation and performance which challenges the cooled semiconductor detectors. A hybrid array technology, exploiting ferroelectric ceramic materials is the basis of a successful range of two dimensional arrays. The success is based on hot pressed ceramic (operated in both pyroelectric and dielectric bolometer modes), and the technologies for solder bump bonding and element reticulation. Arrays have been made with up to 105 elements at pitches down to 40 micrometer, thus providing high resolution in compact systems. Ferroelectrics have now been produced as thin films with high figures of merit and, once deposition techniques compatible with silicon integrated circuits have been demonstrated, these will allow a more direct array fabrication. These integrated array technologies have potential for high yield and low cost arrays of very large numbers of elements. Thermal imaging systems research has led to a signal conditioning architecture optimized for pyroelectric and dielectric bolometer arrays and exploiting the ac coupling of the ferroelectric response to the radiation. The resulting compact sensors give high image quality with low fixed pattern nose in reliable, low power formats.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper will be divided into two parts. In the first, the meaning of marginal ethos will be sketched and some typical problems involved in a pluralistic society governed by marginal ethics will be described. In the second, an attempt will be made to construct a statement of the requirements for price justice under current conditions. This approach will serve the following purposes: (1) it will give us some basis for attacking the problems outlined in the first part; (2) it will avoid the endless debate surrounding the historical meaning and justification of the Just Price doctrines. I The ethos of competitive society, according to my understanding of Dr. Brief's program, is characterized by atomistic individuals seek? ing their own serf-interest by means within the law. The law for its part offers but a bare minimum resistance to competitive business practices. Under these conditions one can conceive of a scale of business actions roughly characterized as more than respectable, barely respectable, and less than respectable. Respectability, of course, is defined in terms of the de facto judgments of the community. The businessman, however, who cuts corners a little bit stands to gain a differential profit. This would be known as an example of sub-marginal ethics. This type of action forces imitation by other businessmen, in sheer self-defense. Logically, there is no end to this downward spiral short of ruin for some of the businessmen and perhaps greatly enhanced power for the rest

The problem of money, a baffling but always intriguing mystery, added to a discussion of the economic role of the government or state ?a topic on which the centuries have cast much heat and some light ?may constitute a formidable challenge to our intellectual digestion. Nevertheless, that topic must be faced unless we are to shirk our obligations. For, in the words of the late Professor Durbin, "econ? omists are the paid 'remembrancers' of the public conscience." It is our function to "denounce the specious pleas . . . and to summon the lazy citizen to repentance."1 This particular combination of problems has been too long neglected by most Catholics?for reasons that I shall not attempt to discover now. As a consequence, we face the danger that our writings will always be post-mortems, showing what we do not like about a past situation but furnishing no specific direction for the future. In one sense, too, we are traitors to our tradition; for "the question of money was the first eco? nomic question to receive systematic treatment from the writers of the later Middle Ages."2 Recently, however, a new Catholic book treat? ing the "major issues of today" contained exactly four insignificant references to money. Proper circumscription of the problem to be treated in this paper requires explicit declaration that our major assumptions include: (1) a a peace-time economy, (2) in a free, democratic society, (3) in an ad? vanced industrial country, not ruined or substantially damaged by war or catastrophe, and (4) with a stable and well-established government. Roughly, our assumptions restrict the discussion to countries such as the United States at peace. If, therefore, our remarks are to be applied to other countries, necessary qualifications should be made. For the sake of completeness, however, and to forestall objections, we shall take a few moments at the beginning to mention several points on the role of the State in an economy at war and in two types of abnormal peace-time situations.

The mechanism by which tumor allografts escape host immunologic attack was investigated. B16-BL6 cells (the bladder 6 subline of the B16 melanoma) (H-2b) were transfected with a gene (Dd) encoding an allogeneic class I major histocompatibility complex antigen. Clones that expressed Dd antigen were injected into the footpads of nonimmune syngeneic mice, syngeneic immune mice, and nude mice. Under conditions of immunologic selection a clone that contained multiple copies of the transfected gene formed variants that lacked the transfected gene. Primary tumors and pulmonary metastases of immunized mice and pulmonary metastases of nonimmunized mice had lost the Dd gene and, in most cases, all of the associated plasmid. In contrast, in immunodeficient nude mice, primary tumors and pulmonary metastases retained the Dd gene and the associated plasmid. Deletion of genes encoding cell surface antigens may be one of the mechanisms by which allogeneic tumors escape immunologic attack.