Elevated S100A8 protein expression in breast cancer cells and breast tumor stroma is prognostic of poor disease outcome

PURPOSE

Elevated S100A8 expression has been observed in cancers of the bladder, esophagus, colon, ovary, and breast. S100A8 is expressed by breast cancer cells as well as by infiltrating immune and myeloid cells. Here we investigate the association of elevated S100A8 protein expression in breast cancer cells and in breast tumor stroma with survival outcomes in a cohort of breast cancer patients.

PATIENTS AND METHODS

Tissue microarrays (TMA) were constructed from breast cancer specimens from 417 patients with stage I-III breast cancer treated at the University of Michigan Comprehensive Cancer Center between 2004 and 2006. Representative regions of non-necrotic tumor and distant normal tissue from each patient were used to construct the TMA. Automated quantitative immunofluorescence (AQUA) was used to measure S100A8 protein expression, and samples were scored for breast cancer cell and stromal S100A8 expression. S100A8 staining intensity was assessed as a continuous value and by exploratory dichotomous cutoffs. Associations between breast cancer cell and stromal S100A8 expression with disease-free survival and overall survival were determined using the Kaplan-Meier method and Cox proportional hazard models.

RESULTS

High breast cancer cell S100A8 protein expression (as indicated by AQUA scores), as a continuous measure, was a significant prognostic factor for OS [univariable hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.00-1.55, p = 0.05] in this patient cohort. Exploratory analyses identified optimal S100A8 AQUA score cutoffs within the breast cancer cell and stromal compartments that significantly separated survival curves for the complete cohort. Elevated breast cancer cell and stromal S100A8 expression, indicated by higher S100A8 AQUA scores, significantly associates with poorer breast cancer outcomes, regardless of estrogen receptor status.

CONCLUSIONS

Elevated breast cancer cell and stromal S1008 protein expression are significant indicators of poorer outcomes in early stage breast cancer patients. Evaluation of S100A8 protein expression may provide additional prognostic information beyond traditional breast cancer prognostic biomarkers.

Abstract P4-12-13: High intratumoral and stromal S100A8 expression is prognostic of poor outcome in breast cancer

Background: S100A8 and S100A9 are members of a family of calcium binding proteins that regulate inflammatory response, and are biomarkers of inflammatory diseases, S100A8/A9 preferentially form heterodimers that interact with their receptor, RAGE, to activate signaling pathways (ERK1/2 MAPK, JNK, and NF-κB) and stimulate tumor cells. Elevated expression of S100A8/A9 has been observed in cancers of the bladder, esophagus, colon, ovary, and breast. S100A8/A9 are expressed intratumorally by cancer cells and in the stroma by infiltrating immune and myeloid cells as well. We investigated the associations of elevated expression of intratumoral and stromal S100A8 with survival outcomes in breast cancer.

Methods: Tissue microarrays (TMA) were constructed from breast cancer specimens from patients with stage I-III breast cancer treated at the University of Michigan Comprehensive Cancer Center between 2004-2006, ensuring a minimum of 10-year follow-up. Each patient was represented on the TMA by representative regions of non-necrotic tumor and distant normal tissue. Automative Quantitative Immunofluorescence (AQUA) was performed for S100A8 protein, and samples were scored for intratumoral and stromal S100A8 expression. S100A8 staining was assessed as a continuous value and by exploratory dichotomous cutoffs. Associations with disease-free survival (DFS) or overall survival (OS) and S100A8 expression, either as continuous value or based on the exploratory cutoffs, were determined using the Kaplan-Meier method and Cox proportional hazards models.

Results: In the entire patient cohort, high intratumoral S100A8 expression, as a continuous measure, was a significant prognostic factor for OS (univariable hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.02-1.56, p=0.036), and for DFS (multivariable HR [95%CI] = 1.24 [1.01-1.53], p = 0.043). Exploratory analyses demonstrated optimal cutoffs of intratumoral and intrastromal staining that greatly separated survival curves. We evaluated whether the prognostic significance of S100A8 expression is different in breast cancer patients based on hormone receptor status and determined that neither intratumoral nor stromal S100A8 expression were significantly associated with outcomes.

Conclusions: Elevated intratumoral and stromal expression of S100A8 are significant indicators of poor outcome in breast cancer patients. These data further support a biological role for S100A8 signaling in mammary carcinogenesis and aggressive tumor behavior. Evaluation of S100A8 protein expression might provide additional prognostic information beyond traditional breast cancer prognostic biomarkers. Further validation is necessary to investigate these findings.

Citation Format: Miller P, Kidwell K, Thomas D, Sabel M, Rae J, Hayes DF, Lippman ME, El-Ashry D. High intratumoral and stromal S100A8 expression is prognostic of poor outcome in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-13.

Abstract P4-03-18: A hierarchy of cancer associated fibroblasts in situ and in circulation promote breast cancer metastasis

Background: Metastasis is the primary cause of breast cancer mortality. Interactions between cancer cells and non-cancer cells of the tumor microenvironment (TME) are pivotal in governing tumor initiation, progression and metastasis, and cancer associated fibroblasts (CAFs) are critical orchestrators of these interactions. We recently identified circulating CAFs (cCAFs) as a novel circulating biomarker associated with metastatic breast cancer. We established CAF cell lines from dissociated luminal A, ER- Her-2 amplified, and triple-negative/basal-like (TN) breast tumors. We demonstrated that “aggressive” CAFs differentially secrete miRNAs that contribute to ER-negativity, activated growth factor signaling, and induction of EMT in breast cancers compared to “indolent” CAFs. We hypothesized that a hierarchy exists within CAFs regarding their ability to facilitate tumor progression and metastasis. Here we demonstrate that CAFs derived from aggressive TN breast tumors differ from those derived from more indolent Luminal A breast tumors in secretion of cytokines and chemokines that can confer differential effects on the behavior of breast cancer cells. We also demonstrate that “aggressive” CAFs more potently facilitate tumor progression and metastasis than “indolent” CAFs. We additionally evaluated if “aggressive” and “indolent” CAFs differ in their ability to mobilize CTCs and circulating CAFs into circulation.

Methods: Conditioned media (CM) from “aggressive” and “indolent” CAFs was analyzed for chemokine/cytokine expression. Luminal A breast cancer cells (MCF-7) or primary tumor cells from an aggressive TN tumor (DT28) were injected into the mammary fat pad of 6-8 week old female NSG mice, either alone or in combination with CAF19-I or CAF23-A. Tumor progression was monitored and mice were examined for metastasis at necropsy. Tissues were harvested for histology and blood was collected by cardiac puncture. Plasma was analyzed for cytokine/chemokine expression and blood was processed for enumeration of circulating tumor cells (CTCs) and cCAFs.

Results: “Aggressive” CAF CM had significantly higher levels of a number of factors, including IL-8, SDF-1, and CXCL1, compared to “indolent” CAF CM. MCF-7 cells co-injected with “aggressive” CAFs formed tumors much faster than those co-injected with the “indolent” CAFs or without CAFs. While DT28 cells readily form tumors and metastasize in the NSG model, fewer DT28 cells do not form metastases in the timeframe that this same lower number of DT28 cells co-injected with “aggressive” CAFs demonstrated robust tumor growth and developed metastases in liver and pancreas. DT28 cells co-injected with “indolent” CAFs did not exhibit metastases.

Conclusion: The data presented here further demonstrate that there is a hierarchy within CAFs regarding their ability to facilitate tumor growth and metastasis, and that this may largely be mediated by secreted soluble factors. “Aggressive” CAFs may retain their programmed role in circulation and accelerate metastasis more than “indolent” CAFs. We suggest that targeting CAFs in situ and in circulation and disrupting their interactions with breast cancer cells could provide novel strategies to combat breast cancer and breast cancer metastasis.

Citation Format: Sharma U, Miller P, Speransky S, Medina-Saenz K, Ferrer P, Lippman M, El-Ashry D. A hierarchy of cancer associated fibroblasts in situ and in circulation promote breast cancer metastasis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-03-18.

Assessing Model Selection Uncertainty Using a Bootstrap Approach: An update

Model comparisons in the behavioral sciences often aim at selecting the model that best describes the structure in the population. Model selection is usually based on fit indices such as AIC or BIC, and inference is done based on the selected best-fitting model. This practice does not account for the possibility that due to sampling variability, a different model might be selected as the preferred model in a new sample from the same population. A previous study illustrated a bootstrap approach to gauge this model selection uncertainty using two empirical examples. The current study consists of a series of simulations to assess the utility of the proposed bootstrap approach in multi-group and mixture model comparisons. These simulations show that bootstrap selection rates can provide additional information over and above simply relying on the size of AIC and BIC differences in a given sample.

ASPP2 deficiency causes features of 1q41q42 microdeletion syndrome

Chromosomal abnormalities are implicated in a substantial number of human developmental syndromes, but for many such disorders little is known about the causative genes. The recently described 1q41q42 microdeletion syndrome is characterized by characteristic dysmorphic features, intellectual disability and brain morphological abnormalities, but the precise genetic basis for these abnormalities remains unknown. Here, our detailed analysis of the genetic abnormalities of 1q41q42 microdeletion cases identified TP53BP2, which encodes apoptosis-stimulating protein of p53 2 (ASPP2), as a candidate gene for brain abnormalities. Consistent with this, Trp53bp2-deficient mice show dilation of lateral ventricles resembling the phenotype of 1q41q42 microdeletion patients. Trp53bp2 deficiency causes 100% neonatal lethality in the C57BL/6 background associated with a high incidence of neural tube defects and a range of developmental abnormalities such as congenital heart defects, coloboma, microphthalmia, urogenital and craniofacial abnormalities. Interestingly, abnormalities show a high degree of overlap with 1q41q42 microdeletion-associated abnormalities. These findings identify TP53BP2 as a strong candidate causative gene for central nervous system (CNS) defects in 1q41q42 microdeletion syndrome, and open new avenues for investigation of the mechanisms underlying CNS abnormalities.

Body density and diving gas volume of the northern bottlenose whale (Hyperoodon ampullatus)

Diving lung volume and tissue density, reflecting lipid store volume, are important physiological parameters that have only been estimated for a few breath-hold diving species. We fitted 12 northern bottlenose whales with data loggers that recorded depth, 3-axis acceleration and speed either with a fly-wheel or from change of depth corrected by pitch angle. We fitted measured values of the change in speed during 5 s descent and ascent glides to a hydrodynamic model of drag and buoyancy forces using a Bayesian estimation framework. The resulting estimate of diving gas volume was 27.4±4.2 (95% credible interval, CI) ml kg(-1), closely matching the measured lung capacity of the species. Dive-by-dive variation in gas volume did not correlate with dive depth or duration. Estimated body densities of individuals ranged from 1028.4 to 1033.9 kg m(-3) at the sea surface, indicating overall negative tissue buoyancy of this species in seawater. Body density estimates were highly precise with ±95% CI ranging from 0.1 to 0.4 kg m(-3), which would equate to a precision of <0.5% of lipid content based upon extrapolation from the elephant seal. Six whales tagged near Jan Mayen (Norway, 71°N) had lower body density and were closer to neutral buoyancy than six whales tagged in the Gully (Nova Scotia, Canada, 44°N), a difference that was consistent with the amount of gliding observed during ascent versus descent phases in these animals. Implementation of this approach using longer-duration tags could be used to track longitudinal changes in body density and lipid store body condition of free-ranging cetaceans.

Long-term non-invasive interrogation of human dorsal root ganglion neuronal cultures on an integrated microfluidic multielectrode array platform

Scientific studies in drug development and toxicology rely heavily on animal models, which often inaccurately predict the true response for human exposure. This may lead to unanticipated adverse effects or misidentified risks that result in, for example, drug candidate elimination. The utilization of human cells and tissues for in vitro physiological platforms has become a growing area of interest to bridge this gap and to more accurately predict human responses to drugs and toxins. The effects of new drugs and toxins on the peripheral nervous system are often investigated with neurons isolated from dorsal root ganglia (DRG), typically with one-time measurement techniques such as patch clamping. Here, we report the use of our multi-electrode array (MEA) platform for long-term noninvasive assessment of human DRG cell health and function. In this study, we acquired simultaneous optical and electrophysiological measurements from primary human DRG neurons upon chemical stimulation repeatedly through day in vitro (DIV) 23. Distinct chemical signatures were noted for the cellular responses evoked by each chemical stimulus. Additionally, the cell viability and function of the human DRG neurons were consistent through DIV 23. To the best of our knowledge, this is the first report on long-term measurements of the cell health and function of human DRG neurons on a MEA platform. Future generations will include higher electrode numbers in customized arrangements as well as integration with different tissue types on a single device. This platform will provide a valuable testing tool for both rodent and human cells, enabling a more comprehensive risk assessment for drug candidates and toxicants.

Tracking the kinematics of caudal-oscillatory swimming: a comparison of two on-animal sensing methods

Studies of locomotion kinematics require high-resolution information about body movements and the specific acceleration (SA) that these generate. On-animal accelerometers measure both orientation and SA but an additional orientation sensor is needed to accurately separate these. Although gyroscopes can perform this function, their power consumption, drift and complex data processing make them unattractive for biologging. Lower power magnetometers can also be used with some limitations. Here, we present an integrated and simplified method for estimating body rotations and SA applicable to both gyroscopes and magnetometers, enabling a direct comparison of these two sensors. We use a tag with both sensors to demonstrate how caudal-oscillation rate and SA are adjusted by a diving whale in response to rapidly changing buoyancy forces as the lungs compress while descending. The two sensors gave similar estimates of the dynamic forces, demonstrating that magnetometers may offer a simpler low-power alternative for miniature tags in some applications.

WITHDRAWN: Impact of Initial Antibiotic Selection on Adverse Outcomes Among Patients With Severe Sepsis and Septic Shock

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Crit Care Med, 43 (2015) 263, http://dx.doi.org/10.1097/01.ccm.0000474875.35054.b3. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Is the tiger shark Galeocerdo cuvier a coastal species? Expanding its distribution range in the Atlantic Ocean using at-sea observer data

The occurrence of tiger shark Galeocerdo cuvier in the Atlantic Ocean was assessed using at-sea observer data from multiple pelagic longline fisheries. Geographic positions of 2764 G. cuvier recorded between 1992 and 2013 and covering a wide area of the Atlantic Ocean were compared with the currently accepted distribution ranges of the species. Most records fell outside those ranges in both the Southern and Northern Hemispheres, which strongly suggests that the distribution range of G. cuvier in the open ocean is considerably larger than previously described.

Abstract P2-06-03: Leukemia inhibitory factor receptor as a tumor suppressor: A study on migration and invasion of breast cancer cells upon LIFR stimulation

BACKGROUND: Tumorigenesis is the result of a step-wise process during which a mutation activates an oncogene or inactivates a tumor suppressor gene. Identification of these genes is critical in order to develop effective therapies for breast cancer patients. Our group previously discovered the Leukemia Inhibitory Factor Receptor (LIFR) as a novel tumor suppressor gene via an in vivo RNAi screen in HMLE cells. HMLE is a partially transformed non-tumorigenic cell line; these cells can become tumorigenic with a single mutation, such as the Ras mutation that creates the HMLER line. HMLEs were transduced using an shRNA library targeting the entire human genome, and stably transfected cells were xenografted into NOD/SCID mice. Genomic DNA from resultant primary tumors were analyzed for the shRNA sequences that, when integrated, made HMLEs tumorigenic. LIFR emerged from this screen as a novel candidate tumor suppressor gene in breast cancer. Here we report on the decreased migration and invasion of breast cancer cells activated by LIFR stimulation.

METHODS: HMLER cells were plated at 500,000 cells per well of a six-well plate. Twenty-four hours later, HMLERs were treated with 100, 25, 12.5, 5, 2.5, or 0 ng/ml recombinant hLIF. Protein lysates were analyzed for phospho-STAT3 induction upon LIF stimulation. Based on the results, we selected 25 ng/ml as the appropriate hLIF concentration to maximally stimulate LIFR in the migration assay described here. HMLERs were serum starved for 8 hours. DMEM with 10% fetal bovine serum was added to the bottom of the migration assay plate as a chemoattractant. The cells were suspended in DMEM with 0.1% bovine serum albumin and either treated with 25 ng/ml LIF or no LIF. Thereafter, 25,000 cells were added to either a Corning Biocoat Matrigel Invasion Chamber or a control insert lacking a migration matrix. The migration assay plate was incubated at 37°C and the cells were allowed to migrate for 20 hours. Migrated cells were enumerated under the light microscope and a migration percentage was calculated.

RESULTS: In the first portion of the study, we found that low concentrations of LIF (2.5 ng/ml) resulted in p-STAT3 induction in HMLERs, but that p-STAT3 was maximally induced with 25 ng/ml of LIF. In the invasion and migration assay, HMLER cells that had not been treated with LIF displayed an aggressively invasive and migratory phenotype with 61.1% migration in matrigel compared to control inserts without the migration matrix. When HMLERs were treated with 25 ng/ml LIF, the cells displayed decreased invasion and migration with only 50.0% of cells migrating. Based on these results, LIFR stimulation inhibits the invasion and migration of breast cancer cells.

CONCLUSIONS: As a tumor suppressor gene, LIFR is vital to the normal functioning of a non-cancerous cell, and its loss can produce a tumorigenic and metastatic phenotype. Treatment with LIF converts aggressively metastatic breast cancer cells to a less invasive phenotype. Through a deeper understanding of LIFR's tumor suppressor effects, we can harness the anti-tumorigenic and anti-metastatic properties of LIFR stimulation and develop targeted therapies to prevent growth and metastasis of breast cancer.

Citation Format: Dempsey NG, Miller P, Lippman M. Leukemia inhibitory factor receptor as a tumor suppressor: A study on migration and invasion of breast cancer cells upon LIFR stimulation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-06-03.

Providing NHS staff with height-adjustable workstations and behaviour change strategies to reduce workplace sitting time: protocol for the Stand More AT (SMArT) Work cluster randomised controlled trial

BACKGROUND

High levels of sedentary behaviour (i.e., sitting) are a risk factor for poor health. With high levels of sitting widespread in desk-based office workers, office workplaces are an appropriate setting for interventions aimed at reducing sedentary behaviour. This paper describes the development processes and proposed intervention procedures of Stand More AT (SMArT) Work, a multi-component randomised control (RCT) trial which aims to reduce occupational sitting time in desk-based office workers within the National Health Service (NHS).

METHODS/DESIGN

SMArT Work consists of 2 phases: 1) intervention development: The development of the SMArT Work intervention takes a community-based participatory research approach using the Behaviour Change Wheel. Focus groups will collect detailed information to gain a better understanding of the most appropriate strategies, to sit alongside the provision of height-adjustable workstations, at the environmental, organisational and individual level that support less occupational sitting. 2) intervention delivery and evaluation: The 12 month cluster RCT aims to reduce workplace sitting in the University Hospitals of Leicester NHS Trust. Desk-based office workers (n = 238) will be randomised to control or intervention clusters, with the intervention group receiving height-adjustable workstations and supporting techniques based on the feedback received from the development phase. Data will be collected at four time points; baseline, 3, 6 and 12 months. The primary outcome is a reduction in sitting time, measured by the activPAL(TM) micro at 12 months. Secondary outcomes include objectively measured physical activity and a variety of work-related health and psycho-social measures. A process evaluation will also take place.

DISCUSSION

This study will be the first long-term, evidence-based, multi-component cluster RCT aimed at reducing occupational sitting within the NHS. This study will help form a better understanding and knowledge base of facilitators and barriers to creating a healthier work environment and contribute to health and wellbeing policy.

TRIAL REGISTRATION

ISRCTN10967042 . Registered 2 February 2015.

Associations between vasodilatory capacity, physical activity and sleep among younger and older adults

INTRODUCTION

Exercise promotes cardiovascular health through its direct impact on the vascular endothelium. Conversely, poor sleep quality is associated with endothelial dysfunction, which may explain the increased cardiovascular disease amongst poor sleepers. Yet, the influence of physical activity and poor sleep quality on vascular health is not clear.

PURPOSE

This study examined the relationships between forearm vasodilatory capacity, self-reported sleep quality and free-living, actigraphy-derived energy expenditure in a group of young and older community dwelling adults.

METHODS

Venous occlusion plethysmography determined baseline and peak forearm blood flow following reactive hyperemia. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Measures of body composition were assessed using dual energy X-ray absorptiometry.

RESULTS

A total of 104 (61 young; 43 old) participants completed the study. In general, younger participants were more active, as determined by steps per day and average daily energy expenditure, but reported poorer sleep quality. In the combined sample, those who reported moderate sleep disturbances (PSQI total score; 11-15) had significantly lower vasodilatory capacity (16.8 ± 7.6 ml/100 ml/min) compared to those who reported no sleep disturbance (PSQI total score; 0-5) (22.3 ± 7.2 ml/100 ml/min) or mild sleep disturbance (PSQI total score; 6-10) (22.3 ± 8.1 ml/100 ml/min) (p < 0.01). After adjustment for physical activity, total body fat and age, moderately poor sleep remained an independent predictor of forearm vasodilatory capacity.

CONCLUSIONS

These findings suggest that any positive vascular benefits accrued through increased physical activity might be offset by the negative consequences of chronically disturbed sleep.

Taxonomy of rare genetic metabolic bone disorders

This article reports a taxonomic classification of rare skeletal diseases based on metabolic phenotypes. It was prepared by The Skeletal Rare Diseases Working Group of the International Osteoporosis Foundation (IOF) and includes 116 OMIM phenotypes with 86 affected genes.

INTRODUCTION

Rare skeletal metabolic diseases comprise a group of diseases commonly associated with severe clinical consequences. In recent years, the description of the clinical phenotypes and radiographic features of several genetic bone disorders was paralleled by the discovery of key molecular pathways involved in the regulation of bone and mineral metabolism. Including this information in the description and classification of rare skeletal diseases may improve the recognition and management of affected patients.

METHODS

IOF recognized this need and formed a Skeletal Rare Diseases Working Group (SRD-WG) of basic and clinical scientists who developed a taxonomy of rare skeletal diseases based on their metabolic pathogenesis.

RESULTS

This taxonomy of rare genetic metabolic bone disorders (RGMBDs) comprises 116 OMIM phenotypes, with 86 affected genes related to bone and mineral homeostasis. The diseases were divided into four major groups, namely, disorders due to altered osteoclast, osteoblast, or osteocyte activity; disorders due to altered bone matrix proteins; disorders due to altered bone microenvironmental regulators; and disorders due to deranged calciotropic hormonal activity.

CONCLUSIONS

This article provides the first comprehensive taxonomy of rare metabolic skeletal diseases based on deranged metabolic activity. This classification will help in the development of common and shared diagnostic and therapeutic pathways for these patients and also in the creation of international registries of rare skeletal diseases, the first step for the development of genetic tests based on next generation sequencing and for performing large intervention trials to assess efficacy of orphan drugs.

Abstract AS31: MEK inhibition reverses antiestrogen resistance in ovarian cancer (OVCA) via alteration of cell cycle pathways and MAPK/estrogen regulated gene expression

BACKGROUND: It is estimated that 67% of epithelial OVCAs are estrogen receptor (ER) positive. However, the response to anti-estrogen therapy in OVCA remains marginal. The Ras/Raf/MEK/MAPK pathway is hyperactivated in 40% of OVCAs. We have previously shown that estrogens further activate kinases such as Src, ER and Src kinase binding in the cytoplasm suggesting a non-genomic role or ER in OVCA. We postulated that estrogens further activate MAPK signaling and combination ER blockade with MEK inhibition would block cross-talk and increase the efficacy of ER blockade.

METHODS: The effects of treatment with MEK inhibitor (AZD6244) and anti-estrogen (Fulvestrant), each alone or together, on cell cycle and cell survival were evaluated in ER+ OVCA lines in vitro. Drug effects on xenograft tumor growth were assayed in vivo in NOD/SCIDs. Reverse phase protein lysate array (RPPA) analysis and gene expression analysis (GEA) were performed to evaluate biomarkers of drug response. Finally, a previously reported MAPK gene signature identified in breast cancer was analyzed in the OVCA lines treated with AZD6244 and combination treatment. And using alteration of gene expression upon MEKi treatment as suggestive of MAPK regulation, we define a MAPK gene signature originating from ovarian cancer cells.

RESULTS: RPPA analysis of high grade serous tumors from the TCGA (n=408) demonstrates that over 70% of tumors have phosphorylated MEK and MAPK, and patients with ER+ cancers and high pMAPK or pMEK (top50%), have a worse overall survival than those with low pMAPK or pMEK. Estrogen (E2) increases phosphorylation of MEK in ER+ OVCA cells. Fulvestrant caused minimal growth arrest after treatment demonstrating intrinsic resistance. AZD6244 caused loss of pMAPK, partial G1 cell cycle arrest and a modest increase in p27 levels in a dose dependent manner after treatment. However, responsiveness of OVCA cells to fulvestrant increased by addition of AZD6244 in vitro, with synergistic cell cycle arrest mediated by p27 binding to Cyclin E/cdk2 and much greater inhibition of MAPK activity. Gene enrichment analysis showed an increase in the ERB4/MAPK gene set with Fulv alone and the addition of AZD6244 showed that the top 20 gene sets downregulated were all related to replication and cell cycle (ie FOXM1, CyclinE). RPPA confirmed that combination was more effective in decreasing cell cycle promoting proteins (ie FOXM1, Cyclin B1) and upregulating p27. AZD6244 treatment of OVCA lines resulted in differential expression of about ¼ of the breast cancer defined MAPK gene expression signature, and of these, fulvestrant addition to MEK inhibition (MEKi) differentially affected 19 genes, reflective of these being E2 regulated genes. Similarly, of the total MEKi affected genes, a subset were differentially regulated by the addition of fulvestrant indicating putative E2 regulation underlying these genes. Xenograft data showed the greatest decrease in tumor volume with the drug combination compared to either drug alone.

CONCLUSION: Given the majority of primary OVCAs express high MEK/MAPK activity may underlie failure of anti-estrogen therapy. MEK inhibition reverses anti-estrogen resistance in our OVCA models. These data support further pre-clinical and clinical evaluation of combined fulvestrant and MEK inhibition in OVCA.

Citation Format: K. Hew, P. Miller, J. Sun, Z. Wei, G. Zhang, Y. Lu, G. Mills, J. Slingerland, MD, PhD, D. El-Ashry, F. Simpkins. MEK inhibition reverses antiestrogen resistance in ovarian cancer (OVCA) via alteration of cell cycle pathways and MAPK/estrogen regulated gene expression [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS31.

Non-song social call bouts of migrating humpback whales

The use of stereotyped calls within structured bouts has been described for a number of species and may increase the information potential of call repertoires. Humpback whales produce a repertoire of social calls, although little is known about the complexity or function of these calls. In this study, digital acoustic tag recordings were used to investigate social call use within bouts, the use of bouts across different social contexts, and whether particular call type combinations were favored. Call order within bouts was investigated using call transition frequencies and information theory techniques. Call bouts were defined through analysis of inter-call intervals, as any calls within 3.9 s of each other. Bouts were produced significantly more when new whales joined a group compared to groups that did not change membership, and in groups containing multiple adults escorting a female and calf compared to adult only groups. Although social calls tended to be produced in bouts, there were few repeated bout types. However, the order in which most call types were produced within bouts was non-random and dependent on the preceding call type. These bouts appear to be at least partially governed by rules for how individual components are combined.

Lack of TNFR2 expression by CD4+ T cells limits IL-2 production and promotes Th17 differentiation (BA11P.138)

Tumor necrosis factor (TNF) plays dualistic pro-inflammatory and immune suppressive roles that lead to unpredictable outcomes of TNF blockade in autoimmune disease. Recent evidence has identified contrasting co-stimulatory effects of TNF on effector T cells and regulatory T cells in controlling autoimmunity. The objective of this study was to determine whether CD4+ T cell autonomous TNFR1 and TNFR2 differentially regulate IL-2 production. We utilize B10.A 5C.C7 TCR Tg Rag2-/- IL-2-GFP reporter mice that are deficient for TNFR1 and/or TNFR2 and memTNFΔ1-12 FoxP3-GFP reporter mice that encode an uncleavable tmTNF to demonstrate that TNFR2, but not TNFR1, and membrane, but not soluble, TNF promote Il2 promoter activity and decrease Il2 mRNA decay to increase IL-2 production in response to CD4+ T cell stimulation. We further demonstrate differential DNA binding of NF-κB in TNFR1- and TNFR2-deficient CD4+ T cells following activation. Adoptive transfer of naive CD4+ T cells from TNFR2-deficient IL-2-GFP heterozygous (IL-2+/-), but not IL-2-GFP homozygous (IL-2-/-), 5C.C7 Rag2-/- TCR Tg mice into B10.A Rag2-/- hosts and subsequent immunization with MCC88-103 + LPS yielded greater IL-17 production upon CD4+ T cell re-challenge in comparison to transfer of TNFR2-sufficient 5C.C7 TCR CD4+ T cells. Taken together, these results suggest that selective blockade of TNFR2 on CD4+ T cells is sufficient to inhibit IL-2 production and promote TH17 differentiation.