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PDF file, 91KB, Population Pharmacodynamic Parameter Estimates for Anti-Cancer Agents.

PDF file, 50KB.

PDF file, 58KB, Representative plots of mean tumor volume versus time are shown for dose ranging studies with various anti-cancer agents in xenograft/allograft mice.

PDF file, 43KB, Representative plots of mean tumor volume versus time are shown for A549, H520, Calu-6 and H460 xenografts given daily oral doses of erlotinib at 50 mg/kg.

PDF file - 70K, Listing of References for Clinical Response and Human Pharmacokinetics

PDF file, 74KB, Dose and Schedule Information for Xenograft/ Allograft Studies for Anti-Cancer Agents.

Supplemental Dataset 1. Expression of AXL, GAS6, Vimentin and E-Cadherin in 644 human cancer cell line using RNAseq technology.

Timelapse movie of HeLa cells treated with R428 (1μM).

Timelapse movie of HeLa cells treated with DMSO.

Timelapse movie of HeLa cells treated with docetaxel (3nM).

Supplemental Dataset 3. Tumor cell line profile of docetaxel in combination with R428

Supplemental Dataset 2. Kinome profile with 1000nM R428

Timelapse movie of HeLa cells treated with docetaxel (3nM) in combination with R428 (1μM).

Immunotherapy with checkpoint inhibitors has proved to be highly effective, with durable responses in a subset of patients. Given their encouraging clinical activity, checkpoint inhibitors are increasingly being tested in clinical trials in combination with chemotherapy. In many instances, there is little understanding of how chemotherapy might influence the quality of the immune response generated by checkpoint inhibitors. In this study, we evaluated the impact of chemotherapy alone or in combination with anti–PD-L1 in a responsive syngeneic tumor model. Although multiple classes of chemotherapy treatment reduced immune cell numbers and activity in peripheral tissues, chemotherapy did not antagonize but in many cases augmented the antitumor activity mediated by anti–PD-L1. This dichotomy between the detrimental effects in peripheral tissues and enhanced antitumor activity was largely explained by the reduced dependence on incoming cells for antitumor efficacy in already established tumors. The effects of the various chemotherapies were also agent specific, and synergy with anti–PD-L1 was achieved by different mechanisms that ultimately helped establish a new threshold for response. These results rationalize the combination of chemotherapy with immunotherapy and suggest that, despite the negative systemic effects of chemotherapy, effective combinations can be obtained through distinct mechanisms acting within the tumor.

Targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) can induce regression of tumors bearing activating mutations in the Ras pathway but rarely leads to tumor eradication. Although combining MEK inhibition with T-cell-directed immunotherapy might lead to more durable efficacy, T cell responses are themselves at least partially dependent on MEK activity. We show here that MEK inhibition did profoundly block naive CD8(+) T cell priming in tumor-bearing mice, but actually increased the number of effector-phenotype antigen-specific CD8(+) T cells within the tumor. MEK inhibition protected tumor-infiltrating CD8(+) T cells from death driven by chronic TCR stimulation while sparing cytotoxic activity. Combining MEK inhibition with anti-programmed death-ligand 1 (PD-L1) resulted in synergistic and durable tumor regression even where either agent alone was only modestly effective. Thus, despite the central importance of the MAP kinase pathway in some aspects of T cell function, MEK-targeted agents can be compatible with T-cell-dependent immunotherapy.

Summary Clearance of apoptotic cells by macrophages prevents excessive inflammation and supports immune tolerance. Here, we examined the effect of blocking apoptotic cell clearance on anti-tumor immune response. We generated an antibody that selectively inhibited efferocytosis by phagocytic receptor MerTK. Blockade of MerTK resulted in accumulation of apoptotic cells within tumors and triggered a type I interferon response. Treatment of tumor-bearing mice with anti-MerTK antibody stimulated T cell activation and synergized with anti-PD-1 or anti-PD-L1 therapy. The anti-tumor effect induced by anti-MerTK treatment was lost in Stinggt/gt mice, but not in Cgas−/− mice. Abolishing cGAMP production in Cgas−/− tumor cells, depletion of extracellular ATP, or inactivation of the ATP-gated P2X7R channel also compromised the effects of MerTK blockade. Mechanistically, extracellular ATP acted via P2X7R to enhance the transport of extracellular cGAMP into macrophages and subsequent STING activation. Thus, MerTK blockade increases tumor immunogenicity and potentiates anti-tumor immunity, which has implications for cancer immunotherapy.

Autophagy is a cell survival process essential for the regulation of immune responses to infections. However, the role of T cell autophagy in anti-tumor immunity is less clear. Here, we demonstrate a cell-autonomous role for autophagy in the regulation of CD8

Diverse biological roles for mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) have necessitated the identification of potent inhibitors in order to study its function in various disease contexts. In particular, compounds that can be used to carry out such studies in vivo would be critical for elucidating the potential for therapeutic intervention. A structure-based design effort coupled with property-guided optimization directed at minimizing the ability of the inhibitors to cross into the CNS led to an advanced compound 13 (GNE-495) that showed excellent potency and good PK and was used to demonstrate in vivo efficacy in a retinal angiogenesis model recapitulating effects that were observed in the inducible Map4k4 knockout mice.

Expectations for parent involvement in their children's education have risen dramatically over the last 20 years. The demands now placed on parents to evaluate and select educational options for their children, to act as advocates for their children, and to support increasingly demanding academic standards have never been greater. Strong partnerships between home and school can increase opportunities for students. Understanding the nature of these significant changes and how parents may be affected by them is a critical first step.

Cell migration is a stepwise process that coordinates multiple molecular machineries. Using in vitro angiogenesis screens with short interfering RNA and chemical inhibitors, we define here a MAP4K4–moesin–talin–β1-integrin molecular pathway that promotes efficient plasma membrane retraction during endothelial cell migration. Loss of MAP4K4 decreased membrane dynamics, slowed endothelial cell migration, and impaired angiogenesis in vitro and in vivo. In migrating endothelial cells, MAP4K4 phosphorylates moesin in retracting membranes at sites of focal adhesion disassembly. Epistasis analyses indicated that moesin functions downstream of MAP4K4 to inactivate integrin by competing with talin for binding to β1-integrin intracellular domain. Consequently, loss of moesin (encoded by the MSN gene) or MAP4K4 reduced adhesion disassembly rate in endothelial cells. Additionally, α5β1-integrin blockade reversed the membrane retraction defects associated with loss of Map4k4 in vitro and in vivo. Our study uncovers a novel aspect of endothelial cell migration. Finally, loss of MAP4K4 function suppressed pathological angiogenesis in disease models, identifying MAP4K4 as a potential therapeutic target. A new MAP4K4–moesin–talin–β1-integrin pathway regulating endothelial cell motility was discovered through chemical and siRNA screens; loss of Map4k4 or inhibition of MAP4K4 kinase activity altered the sprout morphology of endothelial cells during angiogenesis by blocking moesin phosphorylation, which regulates the disassembly of focal adhesions, demonstrating that this pathway is involved in both normal and pathological angiogenesis. Cell migration is crucial in important biological processes such as embryogenesis, inflammation and angiogenesis, but many aspects of the cell motility machinery remain to be defined at the molecular level. Here Weilan Ye and colleagues identify a previously unknown pathway regulating endothelial cell motility. Using chemical and RNA screens, they found that a selective inhibitor of MAP4K4 altered the sprout morphology of endothelial cells during angiogenesis. The inhibitor caused endothelial cells to accumulate long, thin subcellular protrusions, suggesting a failure to retract these protrusions. The authors show that MAP4K4 phosphorylates moesin, which regulates the disassembly of focal adhesions by inactivating β1-integrin, and they demonstrate that this MAP4K4–moesin–talin–β1-integrin pathway plays a role in both normal and pathological angiogenesis.

Molecularly targeted drug therapies have revolutionized cancer treatment; however, resistance remains a major limitation to their overall efficacy. Epithelial-to-mesenchymal transition (EMT) has been linked to acquired resistance to tyrosine kinase inhibitors (TKI), independent of mutational resistance mechanisms. AXL is a receptor tyrosine kinase associated with EMT that has been implicated in drug resistance and has emerged as a candidate therapeutic target. Across 643 human cancer cell lines that were analyzed, elevated AXL was strongly associated with a mesenchymal phenotype, particularly in triple-negative breast cancer and non–small cell lung cancer. In an unbiased screen of small-molecule inhibitors of cancer-relevant processes, we discovered that AXL inhibition was specifically synergistic with antimitotic agents in killing cancer cells that had undergone EMT and demonstrated associated TKI resistance. However, we did not find that AXL inhibition alone could overcome acquired resistance to EGFR TKIs in the EMT setting, as previously reported. These findings reveal a novel cotreatment strategy for tumors displaying mesenchymal features that otherwise render them treatment refractory. Cancer Res; 74(20); 5878–90. ©2014 AACR.

Summary: Autophagy is a cell survival process essential for the regulation of immune responses to infections. However, the role of T cell autophagy in anti-tumor immunity is less clear. Here, we demonstrate a cell-autonomous role for autophagy in the regulation of CD8+ T-cell-mediated control of tumors. Mice deficient for the essential autophagy genes Atg5, Atg14, or Atg16L1 display a dramatic impairment in the growth of syngeneic tumors. Moreover, T cells lacking Atg5 have a profound shift to an effector memory phenotype and produce greater amounts of interferon-γ (IFN-γ) and tumor necrosis factor α (TNF-α). Mechanistically, Atg5−/− CD8+ T cells exhibit enhanced glucose metabolism that results in alterations in histone methylation, increases in H3K4me3 density, and transcriptional upregulation of both metabolic and effector target genes. Nonetheless, glucose restriction is sufficient to suppress Atg5-dependent increases in effector function. Thus, autophagy-dependent changes in CD8+ T cell metabolism directly regulate anti-tumor immunity. : DeVorkin et al. show that loss of autophagy enhances CD8+ T-cell-mediated rejection of tumors. Mechanistically, suppression of autophagy shifts T cells to a glycolytic phenotype and causes a reduction in S-adenosylmethionine. As a consequence, autophagy-deficient T cells transcriptionally reprogram immune response genes to an effector memory state. Keywords: autophagy, CD8+ T cells, anti-tumor immunity, glycolysis, lactate, SAM, methylation

Purpose: Immunodeficient mice transplanted with subcutaneous tumors (xenograft or allograft) are widely used as a model of preclinical activity for the discovery and development of anticancer drug candidates. Despite their widespread use, there is a widely held view that these models provide minimal predictive value for discerning clinically active versus inactive agents. To improve the predictive nature of these models, we have carried out a retrospective population pharmacokinetic–pharmacodynamic (PK–PD) analysis of relevant xenograft/allograft efficacy data for eight agents (molecularly targeted and cytotoxic) with known clinical outcome. Experimental Design: PK–PD modeling was carried out to first characterize the relationship between drug concentration and antitumor activity for each agent in dose-ranging xenograft or allograft experiments. Next, simulations of tumor growth inhibition (TGI) in xenografts/allografts at clinically relevant doses and schedules were carried out by replacing the murine pharmacokinetics, which were used to build the PK–PD model with human pharmacokinetics obtained from literature to account for species differences in pharmacokinetics. Results: A significant correlation (r = 0.91, P = 0.0008) was observed between simulated xenograft/allograft TGI driven by human pharmacokinetics and clinical response but not when TGI observed at maximum tolerated doses in mice was correlated with clinical response (r = 0.36, P = 0.34). Conclusions: On the basis of these analyses, agents that led to greater than 60% TGI in preclinical models, at clinically relevant exposures, are more likely to lead to responses in the clinic. A proposed strategy for the use of murine subcutaneous models for compound selection in anticancer drug discovery is discussed. Clin Cancer Res; 18(14); 3846–55. ©2012 AACR.

Given recent trends, middle-class families may become an increasing presence in urban districts. Such parents could help secure badly needed resources and raise expectations. This study of parental involvement in two urban schools suggests that middle-class parental involvement may be more complex than often assumed. The authors find that middle-class parents bring myriad resources to urban schools and can be catalysts for change. However, the relationship between parental involvement and widespread benefit was mediated by parents’ own goals and perspectives as well as by the larger social context. Furthermore, compared to a more individualistic approach to parental involvement, a collective orientation is more sustainable and has greater potential for benefiting all children in the school, without regard to their social class.

Focusing on parental networks—a central dimension of social capital—this article uses ethnographic data to examine social-class differences in the relations between families and schools. We detail the characteristics of networks across different classes and then explore the ways that networks come into play when parents are confronted by problematic school situations. The middle-class parents in our study tended to react collectively, in contrast to working-class and poor parents. The middle-class parents were also uniquely able to draw on contacts with professionals to mobilize the information, expertise, or authority needed to contest the judgments of school officials. We did not find substantial race differences. We affirm the importance of a resource-centered conception of social capital that grants the issue of inequality a predominant place.

On Tuesday, Sep 19, 2017, the NOAA Space Weather Prediction Center and OFCM launched the new Space Weather Operations, Research, and Mitigation website SWORM.GOV. The website provides access to the public to Federal activities supporting the Executive Office of the President National Science and Technology Council SWORM Subcommittee as well as other activities and events relevant to the National Space Weather Enterprise. SWORM.GOV was approved by the SWORM Subcommittee, funded by NOAA, and maintained by OFCM.

Immunotherapeutic agents have shown dramatic success in oncology in recent years and several have been approved in melanoma and lung cancer. One strategy for extending the benefit of immunotherapy is to evaluate these agents in combination with standard of care chemotherapy, with the goal of bringing the benefit of immunotherapy into earlier lines of treatment. We have carried out a systematic evaluation of the effects of different classes of chemotherapeutic agents (including alkylating agents, platinum based agents, and taxanes) on the tumor immune microenvironment of syngeneic murine tumor models (CT26 and MC38) in two different strains of mice (BALB/c and C57BL/6). We found that different chemotherapeutic agents caused markedly different changes in the composition and cell phenotype of the tumor immune environment. The majority of chemotherapeutic agents resulted in a mild to moderate increase in CD8+ T cells in the tumor. Some agents also altered the activation state of these CD8+ cells as measured by the level of PD-1 and IFN-gamma. A subset of the chemotherapeutic agents resulted in profound changes in the number of CD4+ cells, including regulatory T cells, as well as changes in myeloid subpopulations including monocytes, neutrophils, and macrophages. In addition to single agents studies, we carried out combination studies of selected chemo agents with simultaneous addition of anti-PD-L1. Several of these combinations caused pronounced increases in efficacy above single agent treatment. We will present the combination pharmacodynamic marker changes and efficacy of these treatments. Our findings demonstrate that chemotherapeutic agents can stimulate the tumor immune environment, at least transiently, through multiple mechanisms. Different subsets of chemotherapeutic agents display unique changes in the tumor immune infiltrate, and may require different immunotherapeutic approaches. These findings provide a rationale for testing immunotherapy-chemotherapy combinations in the clinic. Citation Format: Marcia P. Belvin, Shiuh-Ming Luoh, Jeanne Cheung, Erin McNamara, Rafael Cubas, Jeong Kim. Effects of chemotherapeutic agents on the tumor immune microenvironment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4898.

There are concerns regarding increased cancer incidence in patients treated with ezetimibe, an inhibitor of the absorption of dietary cholesterol. Here we tested the hypothesis that ezetimibe will accelerate mammary tumorigenesis in rats. The drug was administered at a dose of 1 ppm in an AIN-93G diet that contained 0.3% cholesterol. This experimental diet and control diets that contained either no additions or cholesterol or ezetimibe only, were fed to groups of 30 Sprague-Dawley rats 3 days after they were treated with 50 mg/kg methylnitrosourea (MNU). All rats were euthanized 22 weeks after MNU administration. Tumor multiplicity was significantly smaller in rats fed cholesterol than those fed no cholesterol (1.84 +/- 0.42 vs. 3.86 +/- 0.86 respectively, P0.05), but was significantly greater in the cholesterol/ezetimibe group than the group fed only cholesterol (3.48 +/- 0.59 vs. 1.84 +/- 0.42 respectively, P0.04). The average weight of tumors/rat was also significantly larger in the cholesterol/ezetimibe group than those fed cholesterol alone (5.67 +/- 1.15 vs. 2.56 +/- 0.71 respectively, P0.04). As expected, ezetimibe prevented the cholesterol raising effect of the dietary cholesterol. These results show that ezetimibe reverses the inhibitory effect of dietary cholesterol on the development of rat mammary tumors.

The authors take on the district vs. charter school question. The real question, they say, ought to be whether we favor good schools for all kids. Are we ready to talk about why it’s acceptable to provide a world class public education to kids in well-funded suburban schools while city kids work to bootstrap into the American Dream in Third World conditions with far fewer resources than their suburban peers? A better conversation would untangle our tolerance for this inequality and generate solutions that level the playing field.

Meeting abstracts OX40, a TNFRSF member, is a co-stimulatory molecule expressed on antigen experienced effector T (Teff) and regulatory T (Treg) cells, including infiltrating cells in mouse and human tumors. Activation of OX40 by agonistic antibodies is hypothesized to promote anti-tumor immunity

Molecularly-targeted drug therapies have revolutionized cancer treatment, however, resistance remains a major limitation to their overall efficacy. Epithelial to mesenchymal transition (EMT) has been linked to acquired resistance to tyrosine kinase inhibitors (TKIs), independent of mutational resistance mechanisms. AXL is a receptor tyrosine kinase (RTK) associated with EMT that has been implicated in drug resistance, and has emerged as a candidate therapeutic target. Across 643 human cancer cell lines that were analyzed, we found that elevated AXL was strongly associated with a mesenchymal phenotype, particularly in triple negative breast cancer and non-small cell lung cancer. Here we experimentally established a model system to induced EMT by exposure to TGF-β and we observed that the resulting TGF-β-induced mesenchymal cells exhibit substantially increased AXL expression, become relatively drug-resistant to their appropriate TKI and cross-resistant to a variety of anti-cancer agents. We tested the ability of AXL inhibition to restore erlotinib sensitivity, in both a TGF-β-induced resistance model and in two different models of acquired resistance to erlotinib. Here, our observations do not support the previously reported role for AXL inhibition in overcoming acquired resistance to TKIs in the EMT context. However, in an unbiased screen of small molecule inhibitors of cancer-relevant processes, we discovered that AXL inhibition was specifically synergistic with anti-mitotic agents in killing cancer cells that had undergone EMT and demonstrated associated TKI resistance. Inhibition of AXL in combination with anti-mitotic agents enhances death in mitosis by promoting cells to enter mitosis through the down-regulation of CDK1, resulting in G2M cell cycle arrest. In summary, our findings highlight the utility of combination drug screening to reveal novel potentially useful anti-cancer drug combinations to improve clinical responses. While we did not identify a functional role for AXL in the context of acquired resistance to TKI therapies, we did observe that AXL inhibition may be an effective therapy in the context of mesenchymal tumors, specifically when used in combination with anti-mitotic agents. These findings reveal a novel therapeutic strategy for tumors displaying mesenchymal features that otherwise render them treatment-refractory. Citation Format: Catherine Wilson, Thinh Pham, Xiaofen Ye, Eva Lin, Sara Chan, Erin McNamara, Richard M. Neve, Lisa Belmont, Hartmut Koeppen, Robert L. Yauch, Avi Ashkenazi, Jeff Settleman. AXL tyrosine kinase inhibition selectively sensitizes mesenchymal cancer cells to antimitotic agents. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 693. doi:10.1158/1538-7445.AM2014-693

Immunodeficient mice transplanted subcutaneously with human tumors (xenografts) are a widely used model of preclinical efficacy in the discovery and development of anti-cancer agents. We performed a retrospective population pharmacokinetic-pharmacodynamic (PK-PD) analysis of xenograft efficacy data that accounts for differences in clinical and preclinical drug exposure in order to improve their predictive value. In addition, we investigated the ability of xenograft studies to predict clinical response with newer molecular targeted agents. Data from preclinical and clinical studies with three cytotoxic chemotherapeutic agents (docetaxel, carboplatin, and 5-fluorouracil) and five molecular targeted agents (erlotinib, sunitnib, dasatinib, trastuzumab, and vismodegib) were included in this analysis. Anti-cancer agents were administered at a range of doses to xenograft mice bearing tumors relevant to the cancer of interest. No correlation was observed when comparing clinical response to % tumor growth inhibition (%TGI) at the maximum tolerated dose (MTD) in mice. PK-PD modeling was used to simulate %TGI in xenografts using human exposures at clinically relevant doses. These simulated %TGI in xenografts driven by human drug exposures were found to correlate (r=0.92; p=0.0005) with clinical response, illustrating the importance of taking into account species differences in drug exposure when interpreting xenograft data. Distinct differences were observed in the anti-tumor activity of sunitinib in Colo205 colorectal (simulated %TGI = 64%) and 786-O renal cell adenocarcinoma (simulated %TGI = 81%) xenografts, and vismodegib in medulloblastoma allografts (simulated %TGI =102%) and D5123 colorectal xenografts (simulated %TGI = 33%). These differences were consistent with the underlying biology of these models and demonstrate the importance of understanding tumor biology when selecting relevant xenograft models for molecular targeted agents. Based on these analyzes, agents that lead to greater than 60% tumor growth inhibition in preclinical models at clinically relevant exposures are more likely to lead to responses in the clinic. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A11.

The Inhibitor of Apoptosis (IAP) protein family members are widely expressed in many cancers, providing a mechanism to protect these cancer cells from apoptosis. The IAP proteins block activation of the canonical and non-canonical NF-kB pathway, the subsequent expression of TNFα and its initiation of the extrinsic apoptosis pathway. IAP proteins also directly bind and inhibit caspases activated during the induction of apoptosis. Using MDA-MB-231 cells as a model system to assess the effect of candidate IAP antagonists on markers of extrinsic and intrinsic pathway inhibition, we observe that the antagonism of the major IAP family members results in apoptosis in vitro and inhibits their tumor growth in nude mice in vivo. These effects are coincident with changes in the cellular levels of IAP family members such as c-IAP1, detected by Western analysis. These data are consistent with previously described autoubiquitination and subsequent proteasomal degradation of c-IAP1 following IAP antagonism. We have developed a high-throughput, quantifiable and sensitive assay to measure c-IAP1 levels in multiple cell lines, xenografts and in PBMCs using the MesoScale Discovery (MSD) Platform. The c-IAP1 MSD assay has a lower limit of quantification of 1.6 ng/ml of cell lysate, has precision of Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4409. doi:10.1158/1538-7445.AM2011-4409

In 1986 Fordham and Ogbu introduced the idea that black students continue to underperform in school because of their cultural opposition to acting white. This notion of the burden of acting white and Ogbu's cultural ecological theory more broadly have provided one of the dominant theories used to explain the black-white achievement gap. The research presented here offers a reassessment of the burden of acting white and directs researchers to examine the variation to be found in students' peer groups. This article highlights the ability of students to sustain an authentic black identity and to achieve academically by effectively managing their academic success among their peers

This article presents a case study of parents' involvement with their third-grade children. Using interviews and classroom observations, the research revealed how some black parents, deeply concemed about the historical legacy of discrimination against blacks in schooling, approach the school with open criticisms. Since educators seek a positive and deferential role for parents in schooling, race appears to play an independent role in parents' ability to comply with educators' requests (although social class also mediates the ways in which black parents express their concerns). The results highlight the difference between possession and activation of capital and the value accorded displays of capital in particular settings. Taken together, the findings suggest the importance of focusing on moments of inclusion and exclusion in examining how individuals activate social and cultural capital