ICAM1 antibody drug conjugates exert potent antitumor activity in papillary and anaplastic thyroid carcinoma

Treatment options for anaplastic thyroid cancer (ATC) and refractory papillary thyroid carcinoma (PTC) are limited and outcomes remain poor. In this study, we determined via bioinformatic expression analyses and immunohistochemistry staining that intercellular adhesion molecule-1(ICAM1) is an attractive target for ATC and PTC. We designed and engineered two ICAM1-directed antibody-drug conjugate (I1-MMAE and I1-DXd), both of which potently and selectively ablate multiple human ATC and PTC cell lines without affecting non-plastic cells in vitro. Furthermore, I1-MMAE and I1-DXd mediated a potent tumor regression in ATC and PTC xenograft models. To develop a precision medicine, we also explored magnetic resonance imaging (MRI) as a non-invasive biomarker detection method to quantitatively map ICAM1 antigen expression in heterogeneous thyroid tumors. Taken together, this study provides a strong rationale for the further development of I1-MMAE and I1-DXd as promising therapeutic candidates to treat advanced PTC and ATC.

A rationally designed ICAM1 antibody drug conjugate eradicates late-stage and refractory triple-negative breast tumors in vivo

Triple-negative breast cancer (TNBC) remains the most lethal form of breast cancer, and effective targeted therapeutics are in urgent need to improve the poor prognosis of TNBC patients. Here, we report the development of a rationally designed antibody drug conjugate (ADC) for the treatment of late-stage and refractory TNBC. We determined that intercellular adhesion molecule-1 (ICAM1), a cell surface receptor overexpressed in TNBC, efficiently facilitates receptor-mediated antibody internalization. We next constructed a panel of four ICAM1 ADCs using different chemical linkers and warheads and compared their in vitro and in vivo efficacies against multiple human TNBC cell lines and a series of standard, late-stage, and refractory TNBC in vivo models. An ICAM1 antibody conjugated with monomethyl auristatin E (MMAE) via a protease-cleavable valine-citrulline linker was identified as the optimal ADC formulation owing to its outstanding efficacy and safety, representing an effective ADC candidate for TNBC therapy.

Abstract 5315: Identification of urinary proteome signatures associated with triple-negative breast cancer

Triple-negative breast cancer (TNBC), an aggressive breast cancer subtype, accounts for ~15% of all breast cancers and is associated with a poor prognosis and high rates of recurrence and distant metastases. Patients diagnosed with TNBC have limited treatment options and are often restricted to chemotherapy-based regimens, in stark contrast to patients with other breast cancer subtypes where the development of targeted therapeutics have significantly improved patient outcomes. TNBC is characterized by the loss of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. This and the genetic and molecular tumor heterogeneity of TNBC has not only limited advances in the development of targeted therapy but also in the identification of biomarkers that can predict disease status and monitor treatment response. Advances in next-generation sequencing technologies have led to the identification of promising clinically actionable mutations however these tests often require invasive procedures to obtain tumor tissue and lack the ability to monitor treatment efficacy or detect recurrence, highlighting the need for non-invasive markers. A number of serum protein biomarkers have been evaluated in TNBC however none have yet to be successfully deployed in the clinic as indicators of disease. We have previously established that the urinary proteome can serve as a source of highly specific and sensitive biomarkers that can detect disease status and stage of multiple cancer types. Within the context of our global proteomics approach to cancer biomarker discovery, we have utilized the SomaScan discovery platform to identify 281 proteins that are differentially expressed in the urine of patients with TNBC compared to the urine of age- and sex-matched controls. The gene expression profiles of these proteins in TNBC tumor tissue were compared to those of normal breast tissue utilizing the R2 Genomics Platform. Proteins whose gene expression profile was consistent with the proteomic data were validated for the ability to distinguish between TNBC and non-TNBC diagnoses using mono-specific ELISAs of patient urine samples. These results demonstrate that a global proteomics approach coupled with clinical gene expression data can be effectively utilized to identify potential biomarkers for TNBC. These findings identify clinically relevant proteins that should be further explored as potential biomarkers in the development of non-invasive diagnostics for TNBC. (This work was supported by the Breast Cancer Research Foundation and the Nile Albright Research Foundation).

Citation Format: Michael N. Lombardo, Roopali Roy, Susan Pories, Meg Lotz, Rama Aldakhlallah, Simon T. Dillon, Towia A. Libermann, Marsha A. Moses. Identification of urinary proteome signatures associated with triple-negative breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5315.

Escape from breast tumor dormancy: The convergence of obesity and menopause

Obesity is associated with an increased risk of, and a poor prognosis for, postmenopausal (PM) breast cancer (BC). Our goal was to determine whether diet-induced obesity (DIO) promotes 1) shorter tumor latency, 2) an escape from tumor dormancy, and 3) an acceleration of tumor growth and to elucidate the underlying mechanism(s). We have developed in vitro assays and PM breast tumor models complemented by a noninvasive imaging system to detect vascular invasion of dormant tumors and have used them to determine whether obesity promotes the escape from breast tumor dormancy and tumor growth by facilitating the switch to the vascular phenotype (SVP) in PM BC. Obese mice had significantly higher tumor frequency, higher tumor volume, and lower overall survival compared with lean mice. We demonstrate that DIO exacerbates mammary gland hyperplasia and neoplasia, reduces tumor latency, and increases tumor frequency via an earlier acquisition of the SVP. DIO establishes a local and systemic proangiogenic and inflammatory environment via the up-regulation of lipocalin-2 (LCN2), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) that may promote the escape from tumor dormancy and tumor progression. In addition, we show that targeting neovascularization via a multitargeted receptor tyrosine kinase inhibitor, sunitinib, can delay the acquisition of the SVP, thereby prolonging tumor latency, reducing tumor frequency, and increasing tumor-free survival, suggesting that targeting neovascularization may be a potential therapeutic strategy in obesity-associated PM BC progression. This study establishes the link between obesity and PM BC and, for the first time to our knowledge, bridges the dysfunctional neovascularization of obesity with the earliest stages of tumor development.

Abstract 3135: Postmenopausal obese mammary adipocytes promote breast tumorigenesis via the LCN2/IL-6/STAT3 signaling axis

Obesity is associated with a substantially increased risk (~50%) and a poor prognosis of breast cancer (BC) in postmenopausal (PM) women. The mechanism(s) underlying obesity-related BC are not clearly understood and, to date, most studies focus on the systemic effects of subcutaneous or visceral adipocytes on BC. We hypothesized that the increased local presence of ‘obese’ mammary adipocytes within the breast microenvironment promotes the acquisition of an invasive and vascular breast tumor cell phenotype and thereby markedly accelerates tumor proliferation and progression. We first asked whether local interactions between mammary adipocytes and BC cells might promote tumor growth and if so, what the underlying mechanism(s) might be. BC cells (ER- and ER+), when treated with the secretome of mammary adipocytes from obese women (ObAdCM), upregulated potent angiogenic/inflammatory factors, including VEGF, bFGF, lipocalin-2 (LCN2), IL-6 and significantly suppressed the angiogenesis inhibitor Tsp-1. ObAdCM stimulated endothelial cell (EC) recruitment by BC cells and increased EC proliferation, indispensable steps in tumor neovascularization. PM ObAdCM significantly stimulated BC cell proliferation, migration and invasion. Both IL-6 and LCN2-neutralization resulted in significant reduction of the ObAdCM-stimulated BC cell migration and proliferation, suggesting that these factors play a role in obesity-mediated BC progression. ObAdCM induced pSTAT3/pAkt signaling in BC cells and IL-6 and LCN2 could independently stimulate pSTAT3 in BC cells. STAT3 inhibition abrogated the ObACDM-mediated effects on BC cell proliferation and migration, suggesting that the pro-tumorigenic effects of PM obese mammary adipocytes are mediated by LCN2/IL-6/STAT3 signaling. Comparative RNAseq analyses identified >30 differentially expressed genes (DEGs) in PM compared to pre-menopausal (Pre-M) obese mammary adipocytes. Furthermore, GO and KEGG enrichment analysis of DEGs suggested an upregulation of PI3K/Akt signaling, ECM-receptor interactions, focal adhesions and lipid/fatty acid metabolism in PM mammary adipocytes. Taken together, our results indicate that obese mammary adipocytes in the breast tumor microenvironment can promote migration, proliferation, invasion and the vascular phenotype of BC cells and suggest that targeting the LCN2/IL-6/STAT3 signaling axis may be a useful strategy in the treatment of obesity-driven breast tumorigenesis. [Supported by NIH RO1CA185530, the Breast Cancer Research Foundation, the Karp Family Foundation and the Nile Albright Research Foundation]

Citation Format: Roopali Roy, Emily Man, Katherine Gonzalez, Lauren Merritt, Cassandra Daisy, Rama Aldakhallah, Liang Sun, Biju Isaac, Shira Rockowitz, Margaret Lotz-Bousvaros, Susan Pories, Marsha A. Moses. Postmenopausal obese mammary adipocytes promote breast tumorigenesis via the LCN2/IL-6/STAT3 signaling axis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3135.

Proteomic Discovery of Noninvasive Biomarkers Associated With Sport-Related Concussions

BACKGROUND AND OBJECTIVES

Sport-related concussions affect millions of individuals across the United States each year, and current techniques to diagnose and monitor them rely largely on subjective measures. Our goal was to discover and validate objective, quantifiable noninvasive biomarkers with the potential to be used in sport-related concussion diagnosis.

METHODS

Urine samples from a convenience series of healthy control collegiate athletes who had not sustained a concussion and athletes who sustained a concussion as diagnosed by a sports medicine physician within 7 days were collected prospectively and studied. Participants also completed an instrumented single-task gait analysis as a functional measure. Participants were recruited from a single collegiate athletic program and were ≥18 years of age and were excluded if they had a concomitant injury, active psychiatric conditions, or preexisting neurologic disorders. Using Tandem Mass Tags (TMT) mass spectroscopy and ELISA, we identified and validated urinary biomarkers of concussion.

RESULTS

Forty-eight control and 47 age- and sex-matched athletes with concussion were included in the study (51.6% female, 48.4% male, average age 19.6 years). Participants represented both contact and noncontact sports. All but 1 of the postconcussion participants reported experiencing symptoms at the time of data collection. Insulin-like growth factor 1 (IGF-1) and IGF binding protein 5 (IGFBP5) were downregulated in the urine of athletes with concussions compared to healthy controls. Multivariable risk algorithms developed to predict the probability of sport-related concussion showed that IGF-1 multiplexed with single-task gait velocity predicts concussion risk across a range of postinjury time points (area under the curve [AUC] 0.786, 95% confidence interval [CI] 0.690-0.884). When IGF-1 and IGFBP5 are multiplexed with single-task gait velocity, they accurately distinguish between healthy controls and individuals with concussion at acute time points (AUC 0.835, 95% CI 0.701-0.968, p < 0.001).

DISCUSSION

These noninvasive biomarkers, discovered in an objective and validated manner, may be useful in diagnosing and monitoring sport-related concussions in both acute phases of injury and several days after injury.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02354469 (submitted February 2015, first patient enrolled August 2015).

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that urinary IGF-1 and IGFBP5 multiplexed with single-task gait velocity may be useful in diagnosing sport-related concussion.

Association between urinary biomarkers MMP-7/TIMP-2 and reduced renal function in children with ureteropelvic junction obstruction

IMPORTANCE

Extracellular matrix proteins and enzymes involved in degradation have been found to be associated with tissue fibrosis and ureteropelvic junction obstruction (UPJO). In this study we developed a promising urinary biomarker model which can identify reduced renal function in UPJ obstruction patients. This can potentially serve as a non-invasive way to enhance surgical decision making for patients and urologists.

OBJECTIVE

We sought to develop a predictive model to identify UPJO patients at risk for reduced renal function.

DESIGN

Prospective cohort study.

SETTING

Pre-operative urine samples were collected in a prospectively enrolled UPJO biomarker registry at our institution. Urinary MMP-2, MMP-7, TIMP-2, and NGAL were measured as well as clinical characteristics including hydronephrosis grade, differential renal function, t1/2, and UPJO etiology.

PARTICIPANTS

Children who underwent pyeloplasty for UPJO.

MAIN OUTCOME MEASUREMENT

Primary outcome was reduced renal function defined as MAG3 function <40%. Multivariable logistic regression was applied to identify the independent predictive biomarkers in the original Training cohort. Model validation and generalizability were evaluated in a new UPJO Testing cohort.

RESULTS

We included 71 patients with UPJO in the original training cohort and 39 in the validation cohort. Median age was 3.3 years (70% male). By univariate analysis, reduced renal function was associated with higher MMP-2 (p = 0.064), MMP-7 (p = 0.047), NGAL (p = 0.001), and lower TIMP-2 (p = 0.033). Combining MMP-7 with TIMP-2, the multivariable logistic regression model predicted reduced renal function with good performance (AUC = 0.830; 95% CI: 0.722-0.938). The independent testing dataset validated the results with good predictive performance (AUC = 0.738).

CONCLUSIONS AND RELEVANCE

Combination of urinary MMP-7 and TIMP-2 can identify reduced renal function in UPJO patients. With the high sensitivity cutoffs, patients can be categorized into high risk (aggressive management) versus lower risk (observation).

"The Urinary Proteomic Profile Implicates Key Regulators for Urologic Chronic Pelvic Pain Syndrome (UCPPS): A MAPP Research Network Study"

Urologic chronic pelvic pain syndrome (UCPPS) is a condition of unknown etiology characterized by pelvic pain and urinary frequency and/or urgency. As the proximal fluid of this syndrome, urine is an ideal candidate sample matrix for an unbiased study of UCPPS. In this study, a large, discovery-phase, TMT-based quantitative urinary proteomics analysis of 244 participants was performed. The participants included patients with UCPPS (n = 82), healthy controls (HC) (n = 94), and disparate chronic pain diseases, termed positive controls (PC) (n = 68). Using training and testing cohorts, we identified and validated a small and distinct set of proteins that distinguished UCPPS from HC (n = 9) and UCPPS from PC (n = 3). The validated UCPPS: HC proteins were predominantly extracellular matrix/extracellular matrix modifying or immunomodulatory/host defense in nature. Significantly varying proteins in the UCPPS: HC comparison were overrepresented by the members of several dysregulated biological processes including decreased immune cell migration, decreased development of epithelial tissue, and increased bleeding. Comparison with the PC cohort enabled the evaluation of UCPPS-specific upstream regulators, contrasting UCPPS with other conditions that cause chronic pain. Specific to UCPPS were alterations in the predicted signaling of several upstream regulators, including alpha-catenin, interleukin-6, epidermal growth factor, and transforming growth factor beta 1, among others. These findings advance our knowledge of the etiology of UCPPS and inform potential future clinical translation into a diagnostic panel for UCPPS.

•

The proteomics of urinary chronic pelvic pain syndrome (UCPPS) found altered pathways.

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Key changes among the extracellular matrix and inflammatory response proteins were found.

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Several of these pathways and proteins were exclusively altered in UCPPS.

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These findings may have diagnostic and/or therapeutic potential in the future.

A facile magnetic extrusion method for preparing endosome-derived vesicles for cancer drug delivery

To date, the scaled-up manufacturing and efficient drug loading of exosomes are two existing challenges limiting the clinical translation of exosome-based drug delivery. Herein, we developed a facile magnetic extrusion method for preparing endosome-derived vesicles, also known as exosome mimetics (EMs), which share the same biological origin and similar morphology, composition, and biofunctions with native exosomes. The high yield and consistency of this magnetic extrusion method help to overcome the manufacturing bottleneck in exosome research. Moreover, the proposed standardized multi-step method readily facilitates the ammonium sulfate gradient approach to actively load chemodrugs such as doxorubicin into EMs. The engineered EMs developed and tested here exhibit comparable drug delivery properties as do native exosomes and potently inhibit tumor growth by delivering doxorubicin in an orthotopic breast tumor model. These findings demonstrate that EMs can be prepared in a facile and scaled-up manner as a promising biological nanomedicine for cancer drug delivery.

Seeking diagnostic and prognostic biomarkers for childhood bacterial pneumonia in sub-Saharan Africa: study protocol for an observational study

INTRODUCTION

Clinically diagnosed pneumonia in children is a leading cause of paediatric hospitalisation and mortality. The aetiology is usually bacterial or viral, but malaria can cause a syndrome indistinguishable from clinical pneumonia. There is no method with high sensitivity to detect a bacterial infection in these patients and, as result, antibiotics are frequently overprescribed. Conversely, unrecognised concomitant bacterial infection in patients with malarial infections occur with omission of antibiotic therapy from patients with bacterial infections. Previously, we identified two combinations of blood proteins with 96% sensitivity and 86% specificity for detecting bacterial disease. The current project aimed to validate and improve these combinations by evaluating additional biomarkers in paediatric patients with clinical pneumonia. Our goal was to describe combinations of a limited number of proteins with high sensitivity and specificity for bacterial infection to be incorporated in future point-of-care tests. Furthermore, we seek to explore signatures to prognosticate clinical pneumonia.

METHODS AND ANALYSIS

Patients (n=900) aged 2-59 months presenting with clinical pneumonia at two Gambian hospitals will be enrolled and classified according to criteria for definitive bacterial aetiology (based on microbiological tests and chest radiographs). We will measure proteins at admission using Luminex-based immunoassays in 90 children with definitive and 160 with probable bacterial aetiology, and 160 children classified according to the prognosis of their disease. Previously identified diagnostic signatures will be assessed through accuracy measures. Moreover, we will seek new diagnostic and prognostic signatures through machine learning methods, including support vector machine, penalised regression and classification trees.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Gambia Government/Medical Research Council Unit The Gambia Joint Ethics Committee (protocol 1616) and the institutional review board of Boston University Medical Centre (STUDY00000958). Study results will be disseminated to the staff of the study hospitals, in scientific seminars and meetings, and in publications.

TRIAL REGISTRATION NUMBER

H-38462.

The role of extracellular vesicles in the physiological and pathological regulation of the blood-brain barrier

Extracellular vesicles (EVs) are a subclass of biological nanoparticles secreted by most cell types. Once secreted, EVs can travel long distances to deliver their content to target cells thereby playing a key role in cell-to-cell communication and supporting both physiological and pathological processes. In recent years, the functional versatility of EVs has come to be more widely appreciated. Their heterogeneous structure encloses solubilized bioactive cargoes including proteins and nucleic acids. EVs mirror the secreting cell in composition therefore representing a novel source of diagnostic and prognostic biomarkers. Moreover, due to their unique structure, EVs constitute a promising class of biocompatible nanovehicles for drug delivery as well. Importantly, and of burgeoning interest, is the fact that EVs have the intrinsic ability to breach biological barriers including the complex blood-brain barrier (BBB), whose restrictive nature represents a significant therapeutic challenge. EVs have been shown to contribute to the progression of a variety of brain diseases including metastatic brain cancer, neurodegenerative diseases, and acute pathologies including infections and ischemia. In this review, the role of EVs in the maintenance and regulation of the BBB under normal physiological and pathologic conditions are discussed. Applications of EVs as therapeutic and diagnostic tools in the treatment of diseases that affect the central nervous system are presented as are limitations hindering their broad translation and potential solutions to resolve them.

A Rationally Designed ICAM1 Antibody Drug Conjugate for Pancreatic Cancer

Outcomes for pancreatic cancer (PC) patients remain strikingly poor with a 5-year survival of less than 8% due to the lack of effective treatment modalities. Here, a novel precision medicine approach for PC treatment is developed, which is composed of a rationally designed tumor-targeting ICAM1 antibody-drug conjugate (ADC) with optimized chemical linker and cytotoxic payload, complemented with a magnetic resonance imaging (MRI)-based molecular imaging approach to noninvasively evaluate the efficiency of ICAM1 ADC therapy. It is shown that ICAM1 is differentially overexpressed on the surface of human PC cells with restricted expression in normal tissues, enabling ICAM1 antibody to selectively recognize and target PC tumors in vivo. It is further demonstrated that the developed ICAM1 ADC induces potent and durable tumor regression in an orthotopic PC mouse model. To build a precision medicine, an MRI-based molecular imaging approach is developed that noninvasively maps the tumoral ICAM1 expression that can be potentially used to identify ICAM1-overexpressing PC patients. Collectively, this study establishes a strong foundation for the development of a promising ADC to address the critical need in the PC patient care.

Association of Longitudinal Changes in Symptoms and Urinary Biomarkers in Patients with Urological Chronic Pelvic Pain Syndrome: A MAPP Research Network Study

PURPOSE

We analyzed a series of novel noninvasive urinary biomarkers for their ability to objectively monitor the longitudinal clinical status of patients with urological chronic pelvic pain syndrome.

MATERIALS AND METHODS

Baseline, 6 and 12-month urine samples were collected (216) and used to quantify vascular endothelial growth factor, vascular endothelial growth factor (VEGF) receptor 1 (R1), neutrophil gelatinase associated lipocalin (NGAL), matrix metalloproteinase-2, matrix metalloproteinase (MMP)-9, and MMP-9/NGAL complex by enzyme-linked immunosorbent assays. Patient symptom changes were classified as improved, stable or worse using a functional clustering algorithm. Proportional odds models were used to evaluate the association between symptom change and urinary biomarkers.

RESULTS

Across all sampled participants, longitudinal decreases in normalized VEGF concentration (pg/μg) were associated with pain severity improvement, and decreases in MMP-9, NGAL and VEGF-R1 concentration (pg/ml) as well as NGAL normalized concentration were associated with improved urinary symptoms. Longitudinal decreases in normalized VEGF-R1 were associated with pain improvement in patients with moderate widespreadness, no bladder symptoms and no painful filling. Lower baseline normalized VEGF-R1 concentration was associated with pain improvement in patients with pelvic pain only. Higher baseline MMP-9/NGAL levels were associated with pain and urinary improvement across all participants. Moreover, longitudinal increases in MMP-2 concentration was associated with improved pain in men and patients with painful filling.

CONCLUSIONS

Our results suggest these urinary biomarkers may be useful in monitoring urological chronic pelvic pain syndrome symptom changes with respect to both urinary severity and pain severity. With further testing, they may represent objective biological measures of urological chronic pelvic pain syndrome progression and/or resolution while also providing insight into the pathophysiology of urological chronic pelvic pain syndrome.

Cancer Nanomedicines in an Evolving Oncology Landscape

Nanomedicine represents an important class of cancer therapy. Clinical translation of cancer nanomedicine has significantly reduced the toxicity and adverse consequences of standard-of-care chemotherapy. Recent advances in new cancer treatment modalities (e.g., gene and immune therapies) are profoundly changing the oncology landscape, bringing with them new requirements and challenges for next-generation cancer nanomedicines. We present an overview of cancer nanomedicines in four emerging oncology-associated fields: (i) gene therapy, (ii) immunotherapy, (iii) extracellular vesicle (EV) therapy, and (iv) machine learning-assisted therapy. We discuss the incorporation of nanomedicine into these emerging disciplines, present prominent examples, and evaluate their advantages and challenges. Finally, we discuss future opportunities for next-generation cancer nanomedicines.

Abstract 121: Mammary adipocytes drive breast tumor progression and angiogenesis via the VEGF/IL6/STAT3 signaling axis

Obesity is associated with a substantially increased risk (~50%) and a poor prognosis of breast cancer (BC) in postmenopausal (PM) women. The mechanism(s) underlying obesity-related BC are not clearly understood and, to date, most studies focus on the systemic effects of subcutaneous or visceral adipocytes on BC. We hypothesize that the increased local presence of ‘obese' mammary adipocytes within the breast microenvironment promotes the acquisition of an angiogenic and invasive breast tumor cell phenotype and thereby markedly accelerates tumor proliferation and progression. We first asked whether local interactions between mammary adipocytes and BC cells might promote tumor growth and if so, what the underlying mechanism(s) might be. Preadipocytes isolated from mammary adipose tissues of overweight/obese pre- (Pre-M; n=7) and post-menopausal (PM; n=9) women were differentiated into mature adipocytes using standard protocols. The effects of both normal (NA) and cancer-associated (CAA) mammary adipocyte secretome from Pre-M and PM obese women were tested on human and mouse BC cell lines respectively. BC cells (MDA-MB-436, MCF-7, M-Wnt), when treated with the secretome of mammary adipocytes from obese women (ObAd-CM), upregulated potent angiogenic factors, including VEGF-A, Angiopoietin-1, Jagged 1, HIF1-α and bFGF and significantly suppressed the angiogenesis inhibitor Tsp-1. ObAd-CM from both Pre-M and PM women significantly stimulated BC cell proliferation, migration and invasion. Importantly, compared to Pre-M patients, CAA Ad-CM from PM patients promoted higher levels of BC cell proliferation, migration and invasion. Pre-treatment with ObAd-CM resulted in increased endothelial cell (EC) recruitment by BC cells, an indispensable step in tumor angiogenesis. This effect was reversed by VEGF neutralization. In addition, ObAd-CM treatment significantly increased EC proliferation and capillary tube formation. Adipokines such as IL-6, IL-8, MCP-1, adiponectin and leptin were highly expressed in ObAd-CM. Of these, IL-6 neutralization alone inhibited the ObAd-CM-induced migratory and invasive phenotype of BC cells. Treatment with ObAd-CM also resulted in significant activation of pSTAT3, pAkt and pErk in BC cells. STAT3 inhibition reversed the ObAd-CM-mediated effects on BC cell proliferation and migration, suggesting that the pro-tumorigenic effects of Ob mammary adipocytes are mediated via IL-6/STAT3 signaling. Taken together, our results indicate that Ob mammary adipocytes promote migration, proliferation, invasion and the angiogenic phenotype in BC cells and suggest that targeting the VEGF/IL-6/STAT3 signaling axis may be a useful strategy in obesity-driven breast tumor growth and metastasis. [Supported by NIH RO1CA185530, the Karp Family Foundation and the Breast Cancer Research Foundation]

Citation Format: Roopali Roy, Takaya Shimura, Lauren Merritt, Katherine Gonzalez, Emily Man, Margaret Lotz-Bousvaros, Susan Pories, Marsha A. Moses. Mammary adipocytes drive breast tumor progression and angiogenesis via the VEGF/IL6/STAT3 signaling axis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 121.

Cdc42-Dependent Transfer of mir301 from Breast Cancer-Derived Extracellular Vesicles Regulates the Matrix Modulating Ability of Astrocytes at the Blood-Brain Barrier

Breast cancer brain metastasis is a major clinical challenge and is associated with a dismal prognosis. Understanding the mechanisms underlying the early stages of brain metastasis can provide opportunities to develop efficient diagnostics and therapeutics for this significant clinical challenge. We have previously reported that breast cancer-derived extracellular vesicles (EVs) breach the blood-brain barrier (BBB) via transcytosis and can promote brain metastasis. Here, we elucidate the functional consequences of EV transport across the BBB. We demonstrate that brain metastasis-promoting EVs can be internalized by astrocytes and modulate the behavior of these cells to promote extracellular matrix remodeling in vivo. We have identified protein and miRNA signatures in these EVs that can lead to the interaction of EVs with astrocytes and, as such, have the potential to serve as targets for development of diagnostics and therapeutics for early detection and therapeutic intervention in breast cancer brain metastasis.

Tumor-Derived Extracellular Vesicles Breach the Intact Blood-Brain Barrier via Transcytosis

The restrictive nature of the blood-brain barrier (BBB) creates a major challenge for brain drug delivery with current nanomedicines lacking the ability to cross the BBB. Extracellular vesicles (EVs) have been shown to contribute to the progression of a variety of brain diseases including metastatic brain cancer and have been suggested as promising therapeutics and drug delivery vehicles. However, the ability of native tumor-derived EVs to breach the BBB and the mechanism(s) involved in this process remain unknown. Here, we demonstrate that tumor-derived EVs can breach the intact BBB in vivo, and by using state-of-the-art in vitro and in vivo models of the BBB, we have identified transcytosis as the mechanism underlying this process. Moreover, high spatiotemporal resolution microscopy demonstrated that the endothelial recycling endocytic pathway is involved in this transcellular transport. We further identify and characterize the mechanism by which tumor-derived EVs circumvent the low physiologic rate of transcytosis in the BBB by decreasing the brain endothelial expression of rab7 and increasing the efficiency of their transport. These findings identify previously unknown mechanisms by which tumor-derived EVs breach an intact BBB during the course of brain metastasis and can be leveraged to guide and inform the development of drug delivery approaches to deliver therapeutic cargoes across the BBB for treatment of a variety of brain diseases including, but not limited to, brain malignancies.

Abstract A44: The obesity and pancreatic cancer connection: Crosstalk between adipose, tumor, and stroma

By the year 2030, pancreatic cancer (PC) is projected to be the second deadliest cancer, bypassing breast, prostate, and colorectal cancer-related fatalities. Obesity and a higher BMI (body mass index) have emerged as major risk factors for this deadly disease. Epidemiologic studies indicate that obesity not only increases the risk of developing PC but also promotes tumor aggressiveness and reduces overall patient survival. The mechanism/s by which the obese microenvironment may influence pancreatic tumor progression and aggressiveness are currently unclear. We hypothesize that the increased local presence of mature adipocytes (in obesity) within the pancreatic microenvironment markedly enhances the tumorigenic functions of pancreatic tumors and tumor-associated stroma, thereby promoting PC progression. Mature visceral adipocytes and pancreatic cancer (PC) and pancreatic stellate (PSC) cell lines were used to conduct a variety of in vitro functional assays, including migration, proliferation, gemcitabine chemoresistance, and development of a fibrotic phenotype, to determine whether local interactions between adipocytes and tumor cells promote PC growth and to identify the underlying mechanism/s. Treatment with adipocyte conditioned medium (AdCM) stimulated significantly higher cell migration and invasion rates in PCs (MiaPaca-2, AsPC-1 and BxPC-3) and increased migration in PSCs (HImPSC) compared to serum-free or normal human fibroblast CM. The AdCM-mediated migration was dose dependent and adipocyte specific. AdCM treatment also resulted in a significant increase in proliferation of PCs and PSCs. Given that the development of chemoresistance is a critical challenge in PC therapy, we next investigated the effects of adipocytes on PC cell gemcitabine toxicity. Pretreatment with AdCM resulted in 50-70% increased cell viability for PC and PSCs in the presence of gemcitabine. Since extensive fibrosis is a hallmark of PC, we analyzed the effect of AdCM on excessive ECM production by both PC and PSCs. Compared to cells treated with full medium, AdCM-treated PSC and PC cells significantly upregulated their expression of fibronectin and collagen VI. Phosphoproteome analysis indicated an enrichment of Src family kinases including pSTAT3, pAKT, Hsp90, β-catenin, and Hck in AdCM-treated PCs. Taken together, our results indicate that adipocytes promote cell migration, proliferation, and gemcitabine resistance and induce a fibrotic phenotype in PC and PSC. Current efforts in our laboratory are focused on identifying the adipocyte-secreted factor/s that may mediate these effects. Our findings have the potential to establish a direct causal role for obesity in pancreatic cancer progression as well as to identify relevant pathways in the obesity-pancreatic cancer axis that may be therapeutically targeted in the future. (Supported by The Advanced Medical Research Foundation and The Karp Family Foundation.)

Citation Format: Roopali Roy, Takaya Shimura, Adelle Dagher, Marsha A. Moses. The obesity and pancreatic cancer connection: Crosstalk between adipose, tumor, and stroma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr A44.

Rationally Designed Antibody Drug Conjugates Targeting the Breast Cancer-Associated Endothelium

The promise of antiangiogenic therapy for the treatment of breast cancer has been limited by the inability to selectively disrupt the established tumor vasculature. Here, we report the development of rationally designed antibody drug conjugates (ADCs) that can selectively recognize and attack breast tumor-associated endothelial cells (BTECs), while sparing normal endothelial cells (NECs). We first performed a quantitative and unbiased screening of a panel of cancer-related antigens on human BTECs and identified CD105 as the optimal ADC target on these cells. We then used clinically approved ADC linkers and cytotoxic drugs to engineer two CD105-targeted ADCs: CD105-DM1 and CD105-MMAE and evaluated their in vitro efficacy in human BTECs and NECs. We found that both CD105-DM1 and CD105-MMAE exhibited highly potent and selective cytotoxicity against BTECs with IC₅₀ values of 3.2 and 3.7 nM, respectively, significantly lower than their IC₅₀ values on NECs (8-13 fold). Our proof-of-principle study suggests that CD105-targeted ADCs are promising antiangiogenic agents that have the potential to be used to inhibit the established tumor vasculature of breast tumors in a safe and precise manner.

Quantitative Analysis of Different Cell Entry Routes of Actively Targeted Nanomedicines Using Imaging Flow Cytometry

A rapid, high-throughput, and quantitative method for cell entry route characterization is still lacking in nanomedicine research. Here, we report the application of imaging flow cytometry for quantitatively analyzing cell entry routes of actively targeted nanomedicines. We first engineered ICAM1 antibody-directed fusogenic nanoliposomes (ICAM1-FusoNLPs) and ICAM1 antibody-directed endocytic nanolipogels (ICAM1-EndoNLGs) featuring highly similar surface properties but different cell entry routes: receptor-mediated membrane fusion and receptor-mediated endocytosis, respectively. By using imaging flow cytometry, we characterized their intracellular delivery into human breast cancer MDA-MB-231 cells. We found that ICAM1-FusoNLPs mediated a 2.8-fold increased cell uptake of fluorescent payload, FITC-dextran, with a 2.4-fold increased intracellular distribution area in comparison with ICAM1-EndoNLGs. We also investigated the effects of incubation time and endocytic inhibitors on the cell entry routes of ICAM1-FusoNLP and ICAM1-EndoNLG. Our results indicate that receptor-mediated membrane fusion is a faster and more efficient cell entry route than receptor-mediated endocytosis, bringing with it a significant therapeutic benefit in a proof-of-principle nanomedicine-mediated siRNA transfection experiment. Our studies suggest that cell entry route may be an important design parameter to be considered in the development of next-generation nanomedicines. © 2019 International Society for Advancement of Cytometry.

Abstract 1989: Breast cancer-derived exosomes modulate the endocytic pathway in brain endothelial cells

Breast cancer brain metastasis is associated with high mortality and has shown a rising trend in incidence during the recent years. Given the rapid progression of brain metastasis, elucidation of the early events that lead to brain metastasis will pave the way to identifying potential diagnostic and therapeutic targets for early intervention. To explore the early mechanisms of breast cancer brain metastasis, we focused on the role of breast cancer-derived exosomes in this process. While extensive studies have explored the role of tumor-derived exosomes in tumor progression, the current understanding of the contribution of tumor-derived exosomes to brain metastasis remains limited. Using a mouse model of brain metastasis, we showed that pre-treatment of mice with exosomes derived from the brain-seeking MDA-MB-231 breast cancer cell line (Br-Ex) increases brain metastasis growth. This facilitation of brain metastasis was not observed with exosomes derived from the parental MDA-MB-231 cells (P-Ex). It is widely acknowledged that during early stages of brain metastasis, tumor cells grow along the brain vasculature, the blood brain barrier (BBB). To understand the mechanisms of the exosome-derived facilitation of brain metastasis, we studied the interactions between exosomes and the BBB. Using state-of-the-art models of the BBB and high-resolution microscopy, we have identified, for the first time, the mechanisms by which Br-Ex modulate the endocytic pathway in brain endothelial cells to decrease exosome degradation. Interestingly, our mechanistic studies showed that these effects are induced through the transfer of exosomal miRNAs enriched in Br-EX. Moreover, we have shown that Br-Ex can exclusively change the expression of integrins in brain endothelial cells in a way that it could alter the microenvironment around the BBB in favor of metastatic tumor cells. These findings indicate that exosomes derived from a brain-seeking subpopulation of breast cancer cells can exclusively modify the physiological regulation of the BBB at multiple levels to accelerate metastatic growth in the brain microenvironment. Taken together, these studies increase our understanding of the early events that facilitate brain metastasis and provide multiple potential targets for diagnostic and therapeutic applications in brain metastasis. (This work was supported by the Breast Cancer Research Foundation and NIH R01CA185530.)

Citation Format: Golnaz Morad, Christopher V. Carman, Marsha A. Moses. Breast cancer-derived exosomes modulate the endocytic pathway in brain endothelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1989.

Brainwashed by extracellular vesicles: the role of extracellular vesicles in primary and metastatic brain tumour microenvironment

Brain malignancies, including primary and metastatic brain tumours, are often associated with high mortality, reflecting a need for more effective diagnostics and therapeutics. Despite the different cells of origin, primary and metastatic brain tumours share the same microenvironment, which affects the survival mechanisms adopted by these tumours. Elucidating the mechanisms by which primary and metastatic brain tumours interact with the brain microenvironment can uncover potential targets for clinical applications. Extracellular vesicles have been recognized as intercellular communicators that can contribute to cancer progression and have shown promise as potential cancer biomarkers and therapeutics. Here, we outline the contribution of extracellular vesicles in the tumour–microenvironment interactions in primary and metastatic brain tumours with the goal of providing a guide for future translational research in this area.

Metalloproteinases and their roles in human cancer

It is now widely appreciated that members of the matrix metalloproteinase (MMP) family of enzymes play a key role in cancer development and progression along with many of the hallmarks associated with them. The activity of these enzymes has been directly implicated in extracellular matrix remodeling, the processing of growth factors and receptors, the modulation of cell migration, proliferation, and invasion, the epithelial to mesenchymal transition, the regulation of immune responses, and the control of angiogenesis. Certain MMP family members have been validated as biomarkers of a variety of human cancers including those of the breast, brain, pancreas, prostate, ovary, and others. The related metalloproteinases, the A disintegrin and metalloproteinases (ADAMs), share a number of these functions as well. Here, we explore these essential metalloproteinases and some of their disease-associated activities in detail as well as some of their complementary translational potential. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.

Dual complementary liposomes inhibit triple-negative breast tumor progression and metastasis

Distinguishing malignant cells from non-neoplastic ones is a major challenge in triple-negative breast cancer (TNBC) treatment. Here, we developed a complementary targeting strategy that uses precisely matched, multivalent ligand-receptor interactions to recognize and target TNBC tumors at the primary site and metastatic lesions. We screened a panel of cancer cell surface markers and identified intercellular adhesion molecule-1 (ICAM1) and epithelial growth factor receptor (EGFR) as optimal candidates for TNBC complementary targeting. We engineered a dual complementary liposome (DCL) that precisely complements the molecular ratio and organization of ICAM1 and EGFR specific to TNBC cell surfaces. Our in vitro mechanistic studies demonstrated that DCLs, compared to single-targeting liposomes, exhibited increased binding, enhanced internalization, and decreased receptor signaling. DCLs consistently exhibited substantially increased tumor targeting activity and antitumor efficacy in orthotopic and lung metastasis models, indicating that DCLs are a platform technology for the design of personalized nanomedicines for TNBC.

Approaches to the discovery of non-invasive urinary biomarkers of prostate cancer

Prostate cancer (PCa) continues to be one of the most common cancers in men worldwide. Prostate specific antigen (PSA) measured in blood has been used for decades as an aid for physicians to detect the presence of prostate cancer. However, the PSA test has limited sensitivity and specificity, leading to unnecessary biopsies, overdiagnosis and overtreatment of patients. For these reasons, there is an urgent need for more accurate PCa biomarkers that can detect PCa with high sensitivity and specificity. Urine is a unique source of potential protein biomarkers that can be measured in a non-invasive way. This review comprehensively summarizes state of the art approaches used in the discovery and validation of urinary biomarkers for PCa. Numerous strategies are currently being used in the discovery of urinary biomarkers for prostate cancer including gel-based separation techniques, mass spectrometry, activity-based proteomic assays and software approaches. Antibody-based approaches remain preferred method for validation of candidate biomarkers with rapidly advancing multiplex immunoassays and MS-based targeted approaches. In the last decade, there has been a dramatic acceleration in the development of new techniques and approaches in the discovery of protein biomarkers for prostate cancer including computational, statistical and data mining methods. Many urinary-based protein biomarkers have been identified and have shown significant promise in initial studies. Examples of these potential biomarkers and the methods utilized in their discovery are also discussed in this review.

Abstract 5083: Using proteomics profiling to elucidate the interactions of breast cancer-derived exosomes with the blood-brain barrier

Breast cancer metastasis to brain is associated with a dismal prognosis commonly attributed to a limited understating of the mechanisms driving this pathological process. Elucidation of the early events leading to brain metastasis is essential to the development of more effective therapeutic and diagnostic approaches. With an interest in the role of breast cancer-derived exosomes in brain metastasis, our group has previously shown that exosomes derived from a brain-seeking variant of the breast cancer cell line MDA-MB-231 (Br-Ex) can facilitate brain metastasis by inducing alterations in the protein expression profile of astrocytes, one of the components of the blood brain barrier (BBB). This observation led us to hypothesize that the interaction(s) between exosomes and astrocytes is more efficient compared to brain endothelial cells (ECs) or pericytes, the two additional major components of the BBB, resulting in more prominent alterations in the protein expression profile of astrocytes. To test this hypothesis, we first quantified and compared the uptake of exosomes by brain ECs, astrocytes, and pericytes in vitro. The uptake of Br-Ex by astrocytes was significantly greater than that of brain ECs (P&lt;4e-3) and pericytes (P&lt;1e-3). In contrast, exosomes derived from parental or bone-seeking MDA-MB-231 cells (P-Ex and Bo-Ex, respectively) did not show a preferential uptake by astrocytes. We have also demonstrated the uptake of Br-Ex by astrocytes in vivo. The uptake of exosomes by different cell types predominantly relies on the interaction of exosomal proteins with different receptors on the recipient cells. To determine the exosomal proteins potentially involved in the preferential uptake of Br-Ex by astrocytes, we performed quantitative mass spectrometry on the P-, Bo-, and Br-Ex via Isobaric Tag for Relative and Absolute Quantitation (iTRAQ) analysis. Database searches were performed against human proteins in the SwissProt database and a total of 126 proteins were detected with over 95% confidence. Pairwise comparisons identified a total of 27 and 21 proteins with statistically significant differential expression (P &lt; 0.05) in the Br-Ex compared to the P- and Bo-Ex, respectively. Functional enrichment analysis of the detected proteins demonstrated that proteins belonging to the cell migration and focal adhesion categories were over-represented in the Br-Ex. Among these proteins, a number of integrins and annexins were highly enriched in the Br-Ex and can potentially be involved in the preferential uptake of these exosomes by astrocytes.

These findings indicate that exosomes derived from brain-seeking breast cancer cells can preferentially interact with astrocytes and these interactions can be driven by exosomal integrins and annexins. (The authors are grateful for the support of the Breast Cancer Research Foundation and the Advanced Medical Research Foundation.)

Citation Format: Golnaz Morad, Hasan H. Otu, Simon T. Dillon, Marsha A. Moses. Using proteomics profiling to elucidate the interactions of breast cancer-derived exosomes with the blood-brain barrier [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5083.

Abstract 5122: Obesity promotes tumor growth, reduces breast tumor latency and correlates with neovascularization

Obesity is associated with an increased risk and a poor prognosis for both ER+ and ER- breast cancers (BC). To date, however, few studies have focused on the contribution of obesity to BC. In addition, there is a paucity of in vivo models that reliably recapitulate postmenopausal obesity related to BC development and progression. The goal of this study was to determine whether interactions between adipocytes and breast tumor cells promote BC growth and progression and to identify the underlying mechanism(s) responsible. We found that MDA-MB-436 and MCF-7 BC cells, when treated with the conditioned media of adipocytes from obese individuals (Ad-CM), upregulated a number of angiogenic factors including VEGF-A, Ang-1 and bFGF and suppressed the angiogenic inhibitor Tsp-1. Ad-CM stimulated migration and invasion of MDA-MB-436 and MCF-7 (human) and E-Wnt and M-Wnt (mouse) BC cells. Interestingly, the cellular proliferation rate in response to Ad-CM was stimulated only in the ER+ MCF-7 and E-Wnt cells but not in the ER- BC cells, suggesting that Ad-CM may affect proliferation via an ER-dependent mechanism. After pretreatment with Ad-CM, MDA-MB-436, MCF-7 or M-Wnt BC cells exhibited significantly enhanced EC recruitment as well.

Utilizing two different breast tumor models, an orthotopic model (ER-: luciferase-labeled MDA-436 cells injected into the mammary fat pad of SCID mice) and a transgenic model (ER+: doxycycline-driven conditional MMTV/TWNT/luciferase expression), we investigated whether postmenopausal obesity reduces breast tumor latency, promotes angiogenesis and accelerates tumor growth. To model the effect of obesity on postmenopausal BC, mice were ovariectomized (OVX) before inducing obesity via a high-fat diet (HFD) regimen. In the ER- BC model, obese mice had significantly higher tumor frequency, higher tumor volume, and significantly lower median survival. In the ER+ tumor model, obese mice displayed significantly higher tumor frequency, a significantly shorter tumor latency period and a significantly lower median survival time. Tumors in OVX/HFD animals had significantly higher microvessel density (MVD) and an increased number of SMA+ mature vessels. A majority of tumors in OVX/HFD mice displayed aggressive local invasion into the surrounding fat pad and muscle. Proangiogenic factors such as IL-6 (Interleukin-6) and Lcn2 (lipocalin 2) were ~2-fold higher in the sera of obese tumor-bearing mice as compared to controls. Our data suggest that postmenopausal obesity reduces breast tumor latency and promotes aggressive tumor growth via increased angiogenesis. Ongoing studies in our laboratory are investigating the mechanism(s) by which an obesogenic microenvironment mediates these effects.

*Authors contributed equally.

This work was supported by NIH RO1CA185530.

Citation Format: Roopali Roy*, Jiang Yang*, Takaya Shimura, Lauren Merritt, Adelle Dagher, Lewis Chodosh, Marsha A. Moses. Obesity promotes tumor growth, reduces breast tumor latency and correlates with neovascularization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5122.

Nanomaterial Preparation by Extrusion through Nanoporous Membranes

Template synthesis represents an important class of nanofabrication methods. Herein, recent advances in nanomaterial preparation by extrusion through nanoporous membranes that preserve the template membrane without sacrificing it, which is termed as "non-sacrificing template synthesis," are reviewed. First, the types of nanoporous membranes used in nanoporous membrane extrusion applications are introduced. Next, four common nanoporous membrane extrusion strategies: vesicle extrusion, membrane emulsification, precipitation extrusion, and biological membrane extrusion, are examined. These methods have been utilized to prepare a wide range of nanomaterials, including liposomes, emulsions, nanoparticles, nanofibers, and nanotubes. The principle and historical context of each specific technology are discussed, presenting prominent examples and evaluating their positive and negative features. Finally, the current challenges and future opportunities of nanoporous membrane extrusion methods are discussed.

Urinary kallikrein 10 predicts the incurability of gastric cancer

The current imaging modalities are not sufficient to identify inoperable tumor factors, including distant metastasis and local invasion. Hence, we conducted this study using urine samples to discover non-invasive biomarkers for the incurability of gastric cancer (GC). Urine samples from 111 GC patients were analyzed in this study. The GC cohort was categorized and analyzed according to disease stage and operability. In the discovery phase, protease protein array analysis identified 3 potential candidate proteins that were elevated in the urine of advanced GC patients compared to early GC patients. Among them, urinary kallikrein 10 (KLK10) was positively associated with tumor stage progression. Moreover, the urinary level of KLK10 (uKLK10) was significantly elevated in the urine of patients with inoperable GC compared to operable GC patients (median, 118 vs. 229; P=0.014). The combination of uKLK10, tumor location and tumor size distinguished operability of GC with an area under the curve of 0.859, 82.4% sensitivity and 86.2% specificity. Disease-free survival (DFS) was significantly shorter in GC patients with high uKLK10 compared to those with low uKLK10 (hazard ratio: 3.30 [95% confidence interval, 1.58-6.90] P<0.001). Immunohistochemical analyses also demonstrated a positive correlation between tumor stage and KLK10 expression in GC tissues (r=0.426, P<0.001). In addition, GC patients with high expression of pathological KLK10 (pKLK10) showed a significantly shorter DFS compared to those with low pKLK10 (hazard ratio: 3.79 [95% confidence interval, 1.27-11.24] P=0.010). uKLK10 is a promising non-invasive biomarker for the inoperability and incurability of GC.

Using Atomic Force Microscopy to Predict Tumor Specificity of ICAM1 Antibody-Directed Nanomedicines

Atomic force microscopy (AFM) is a powerful tool to detect in vitro antibody-antigen interactions. To date, however, AFM-measured antibody-antigen interactions have yet to be exploited to predict in vivo tumor specificity of antibody-directed nanomedicines. In this study, we have utilized AFM to directly measure the biomechanical interaction between live triple negative breast cancer (TNBC) cells and an antibody against ICAM1, a recently identified TNBC target. For the first time, we provide proof-of-principle evidence that in vitro TNBC cell-ICAM1 antibody binding force measured by AFM on live cells more precisely correlates with in vivo tumor accumulation and therapeutic efficacy of ICAM1 antibody-directed liposomes than ICAM1 gene and surface protein overexpression levels. These studies demonstrate that live cell-antibody binding force measurements may be used as a novel in vitro metric for predicting the in vivo tumor recognition of antibody-directed nanomedicines.

A Time-lapse, Label-free, Quantitative Phase Imaging Study of Dormant and Active Human Cancer Cells

The acquisition of the angiogenic phenotype is an essential component of the escape from tumor dormancy. Although several classic in vitro assays (e.g., proliferation, migration, and others) and in vivo models have been developed to investigate and characterize angiogenic and non-angiogenic cell phenotypes, these methods are time and labor intensive, and often require expensive reagents and instruments, as well as significant expertise. In a recent study, we used a novel quantitative phase imaging (QPI) technique to conduct time-lapse and labeling-free characterizations of angiogenic and non-angiogenic human osteosarcoma KHOS cells. A panel of cellular parameters, including cell morphology, proliferation, and motility, were quantitatively measured and analyzed using QPI. This novel and quantitative approach provides the opportunity to continuously and non-invasively study relevant cellular processes, behaviors, and characteristics of cancer cells and other cell types in a simple and integrated manner. This report describes our experimental protocol, including cell preparation, QPI acquisition, and data analysis.

ADAM12 Is a Novel Regulator of Tumor Angiogenesis via STAT3 Signaling

ADAM12, (ADisintegrin and metalloproteinase domain-containing protein 12), is upregulated in epithelial cancers and contributes to increased tumor proliferation, metastasis, and endocrine resistance. However, its role in tumor angiogenesis is unknown. Here, we report that ADAM12 is upregulated in the vessels of aggressive breast tumors and exerts key regulatory functions. ADAM12 significantly increases bFGF-mediated angiogenesis in vivo and ADAM12 levels are upregulated in tumors that have undergone a switch to the angiogenic phenotype. Importantly, ADAM12-overexpressing breast tumors display a higher microvessel density (MVD). Our goal was to identify the mechanisms by which tumor-associated ADAM12 promotes angiogenesis. ADAM12 expression in breast tumor cells correlated with a significant upregulation of proangiogenic factors such as VEGF and MMP-9 and downregulation of antiangiogenic factors such as Thrombospondin-1 (THBS1/TSP1) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2). Co-culture with ADAM12-expressing tumor cells promoted endothelial cell (EC) recruitment and capillary tube formation. Conversely, downregulation of endogenous ADAM12 in breast cancer cell lines resulted in reduction of pro-angiogenic factors and EC recruitment. These ADAM12-mediated effects are driven by the activation of EGFR, STAT3 and Akt signaling. Blockade of EGFR/STAT3 or silencing of ADAM12 reversed the proangiogenic tumor phenotype, significantly downregulated pro-angiogenic mitogens and reduced EC recruitment. In human breast cancer tissues, ADAM12 expression was significantly positively correlated with pro-angiogenic factors including VEGF and MMP-9 but negatively associated with TSP1.Implications: These novel findings suggest that ADAM12 regulates EC function and facilitates a proangiogenic microenvironment in a STAT3-dependent manner. A combined approach of targeting ADAM12 and STAT3 signaling in breast cancer may represent a promising strategy to inhibit tumor neovascularization. Mol Cancer Res; 15(11); 1608-22. ©2017 AACR.

Abstract 711: Mechanistic implications of COL1A1 as a prostate cancer biomarker

Prostate cancer (PCa) is the second most frequently diagnosed form of male cancer and shares similar symptoms with BPH (Benign Prostate Hyperplasia), a disease characterized by prostate enlargement. Elevated levels of prostate-specific antigen (PSA) can be observed with either benign or malignant growth of the prostate and therefore cannot effectively discriminate between these two prostate diseases. Currently, a test that sensitively and accurately distinguishes between BPH and localized prostate cancer does not exist creating an urgent need for novel biomarkers that can successfully distinguish between these two prostate diseases. The goal of this study was to identify and validate non-invasive urinary biomarkers that distinguish between BPH and PCa. Our previous proteomic study identified elevated levels of several proteins, including EGF (epidermal growth factor), HE-4 (human epididymis protein 4), COL1A1 (collagen, type I, alpha 1) and other proteins in the urine of PCa patients compared to urine samples from patients with BPH. In this current study we have analyzed and validated the presence of EGF, HE-4 and COL1A1 by enzyme-linked immunosorbent assay (ELISA). Our ELISA experiments revealed that COL1A1 was significantly (P &lt; 0.002) elevated in the urine of patients diagnosed with early or localized PCa vs. BPH. In vitro experiments performed on seven different prostate cell lines identified cells from the tumor microenvironment that secrete the highest levels of COL1A1. Expression of COL1A1 by these cells was confirmed by immunohistochemistry (IHC) using prostate tissue microarrays (TMA). In addition, protein array experiments identified elevated levels of several proteases in the urine of PCa patients, including MMP-9, uPA, ADAM-TS1 and several cathepsins. Substrate gel electrophoresis (zymography) revealed elevated activity of both MMP-9 and MMP-2 in urine from PCa patients. These data suggest that MMP-9 and MMP-2 may participate in the cleavage of collagen type 1, resulting in elevated levels of COL1A1 in urine of PCa patients. We are currently testing this hypothesis. In summary, COL1A1 may represent a novel non-invasive urinary biomarker that can effectively discriminate between BPH vs. localized PCa. (Supported by The Ellison Foundation)

Citation Format: Andrej Jedinak, Camille Vuichoud, Andrew El-Hayek, Katherine Kaplan, Jason Savage, Sarah Prophet, Adam S. Feldman, Kevin A. Camphausen, Kevin R. Loughlin, Marsha A. Moses. Mechanistic implications of COL1A1 as a prostate cancer biomarker [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 711. doi:10.1158/1538-7445.AM2017-711

Abstract 5808: The role of breast cancer-derived exosomes in brain metastasis

The development of brain metastasis is associated with a significant reduction in the survival rate of breast cancer patients. Improving the prognosis of women with brain metastasis from breast cancer relies on the elucidation of the mechanisms underlying this process. Our group and others have shown that the formation of brain metastases occurs along the abluminal side of brain vessels, a process called “vessel co-option”. These observations prompted our hypothesis that the cellular and extracellular matrix (ECM) components of the blood-brain-barrier (BBB) can serve as a pre-metastatic niche for breast cancer brain metastases. The role of tumor-derived exosomes (TEx) in the preparation of a pre-metastatic niche in distant organs has been shown in a number of cancers. To investigate the mechanisms driving the vessel co-option of breast cancer brain metastases, we studied the role of breast cancer-derived exosomes in preparation of the BBB for metastasis formation. Exosomes were isolated from the MDA-MB-231 breast cancer cell line, a brain-seeking variant of these cells, and a bone-seeking variant as a non-brain metastatic control. Brain endothelial cells, astrocytes, and brain vascular pericytes, the three components of the BBB, were treated with exosomes for 3 days to recapitulate the continuous exposure of cells to the circulating TEx in vivo. The treated cells were analyzed for cellular activities relevant to pre-metastatic niche preparation in the brain such as the integrity of the BBB, expression of cytokines, and modulation of the ECM. An initial screen was performed using cytokine antibody arrays and PCR arrays for ECM and adhesion molecules and results were validated in three separate experiments using western blots, ELISA, and Multiplex assays. Exosomes derived from brain-seeking cells significantly increased astrocyte migration and decreased the expression of Integrin β1 in brain endothelial cells, both of which can lead to the disruption of the BBB integrity. Moreover, the expression of Interleukin 8 was increased by TEx in astrocytes. TEx also increased the expression of MMP-3 and -9 (Matrix Metalloproteinases) from an undetectable baseline level and decreased the expression of TIMP-1 and -2 (Tissue Inhibitors of MMPs) in astrocytes. While the importance of these two MMPs for brain metastasis from breast cancer has been previously reported, our study is the first to demonstrate that secretion of these MMPs is triggered by TEx. Surprisingly, we did not observe any significant TEx-derived modulations in the expression of cytokines, ECM, and adhesion molecules in brain pericytes. These findings indicate that within the BBB, astrocytes and endothelial cells, but not pericytes, can be affected by breast cancer-derived exosomes in such a way that can potentially lead to preparation of a suitable niche for future metastasis formation along the brain vasculature. (This work is supported by the Breast Cancer Research Foundation.)

Citation Format: Golnaz Morad, Jiang Yang, Marsha A. Moses. The role of breast cancer-derived exosomes in brain metastasis [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 5808. doi:10.1158/1538-7445.AM2017-5808

Host non-inflammatory neutrophils mediate the engraftment of bioengineered vascular networks

Notwithstanding remarkable progress in vascular network engineering, implanted bioengineered microvessels largely fail to form anastomoses with the host vasculature. Here, we demonstrate that implants containing assembled human vascular networks (A-Grafts) fail to engraft due to their inability to engage non-inflammatory host neutrophils upon implantation into mice. In contrast, unassembled vascular cells (U-Grafts) readily engage alternatively polarized neutrophils, which in turn serve as indispensable mediators of vascular assembly and anastomosis. The depletion of host neutrophils abrogated vascularization in U-Grafts, whereas an adoptive transfer of neutrophils fully restored vascularization in myeloid-depleted mice. Neutrophil engagement was regulated by secreted factors and was progressively silenced as the vasculature matured. Exogenous addition of factors from U-Grafts reengaged neutrophils and enhanced revascularization in A-Grafts, a process that was recapitulated by blocking Notch signaling. Our data suggest that the pro-vascularization potential of neutrophils can be harnessed to improve the engraftment of bioengineered tissues.

Identification of novel non-invasive biomarkers of urinary chronic pelvic pain syndrome: findings from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network

OBJECTIVE

To examine a series of candidate markers for urological chronic pelvic pain syndrome (UCPPS), selected based on their proposed involvement in underlying biological processes so as to provide new insights into pathophysiology and suggest targets for expanded clinical and mechanistic studies.

METHODS

Baseline urine samples from Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study participants with UCPPS (n = 259), positive controls (PCs; chronic pain without pelvic pain, n = 107) and healthy controls (HCs, n = 125) were analysed for the presence of proteins that are suggested in the literature to be associated with UCPPS. Matrix metalloproteinase (MMP)-2, MMP-9, MMP-9/neutrophil gelatinase-associated lipocalin (NGAL) complex (also known as Lipocalin 2), vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGF-R1) and NGAL were assayed and quantitated using mono-specific enzyme-linked immunosorbent assays for each protein. Log-transformed concentration (pg/mL or ng/mL) and concentration normalized to total protein (pg/μg) values were compared among the UCPPS, PC and HC groups within sex using the Student's t-test, with P values adjusted for multiple comparisons. Multivariable logistic regression and receiver-operating characteristic curves assessed the utility of the biomarkers in distinguishing participants with UCPPS and control participants. Associations of protein with symptom severity were assessed by linear regression.

RESULTS

Significantly higher normalized concentrations (pg/μg) of VEGF, VEGF-R1 and MMP-9 in men and VEGF concentration (pg/mL) in women were associated with UCPPS vs HC. These proteins provided only marginal discrimination between UCPPS participants and HCs. In men with UCCPS, pain severity was significantly positively associated with concentrations of MMP-9 and MMP-9/NGAL complex, and urinary severity was significantly positively associated with MMP-9, MMP-9/NGAL complex and VEGF-R1. In women with UCPPS, pain and urinary symptom severity were associated with increased normalized concentrations of MMP-9/NGAL complex, while pain severity alone was associated with increased normalized concentrations of VEGF, and urinary severity alone was associated with increased normalized concentrations of MMP-2. Pain severity in women with UCPPS was significantly positively associated with concentrations of all biomarkers except NGAL, and urinary severity with all concentrations except VEGF-R1.

CONCLUSION

Altered levels of MMP-9, MMP-9/NGAL complex and VEGF-R1 in men, and all biomarkers in women, were associated with clinical symptoms of UCPPS. None of the evaluated candidate markers usefully discriminated UCPPS patients from controls. Elevated VEGF, MMP-9 and VEGF-R1 levels in men and VEGF levels in women may provide potential new insights into the pathophysiology of UCPPS.

A quantitative method for screening and identifying molecular targets for nanomedicine

Identifying a molecular target is essential for tumor-targeted nanomedicine. Current cancer nanomedicines commonly suffer from poor tumor specificity, "off-target" toxicity, and limited clinical efficacy. Here, we report a method to screen and identify new molecular targets for tumor-targeted nanomedicine based on a quantitative analysis. In our proof-of-principle study, we used comparative flow cytometric screening to identify ICAM-1 as a potential target for metastatic melanoma (MM). We further evaluated ICAM-1 as a MM targeting moiety by characterizing its (1) tumor specificity, (2) expression level, (3) cellular internalization, (4) therapeutic function, and (5) potential clinical impact. Quantitation of ICAM-1 protein expression on cells and validation by immunohistochemistry on human tissue specimens justified the synthesis of antibody-functionalized drug delivery vehicles, which were benchmarked against appropriate controls. We engineered ICAM-1 antibody conjugated, doxorubicin encapsulating immunoliposomes (ICAM-Dox-LPs) to selectively recognize and deliver doxorubicin to MM cells and simultaneously neutralize ICAM-1 signaling via an antibody blockade, demonstrating significant and simultaneous inhibitory effects on MM cell proliferation and migration. This paper describes a novel, quantitative metric system that identifies and evaluates new cancer targets for tumor-targeting nanomedicine.

Characterization of dormant and active human cancer cells by quantitative phase imaging

The switch of tumor cells from a dormant, non-angiogenic phenotype to an active, angiogenic phenotype is a critical step in early cancer progression. To date, relatively little is known about the cellular behaviors of angiogenic and non-angiogenic tumor cell phenotypes. In this study, holographic imaging cytometry, a quantitative phase imaging (QPI) technique was used to continuously and non-invasively analyze, quantify, and compare a panel of fundamental cellular behaviors of angiogenic and non-angiogenic human osteosarcoma cells (KHOS) in a simple and economical way. Results revealed that angiogenic KHOS cells (KHOS-A) have significantly higher cell motility speeds than their non-angiogenic counterpart (KHOS-N) while no difference in their cell proliferation rates and cell cycle lengths were observed. KHOS-A cells were also found to have significantly smaller cell areas and greater cell optical thicknesses when compared with the non-angiogenic KHOS-N cells. No difference in average cell volumes was observed. These studies demonstrate that the morphology and behavior of angiogenic and non-angiogenic cells can be continuously, efficiently, and non-invasively monitored using a simple, quantitative, and economical system that does not require tedious and time-consuming assays to provide useful information about tumor dormancy. © 2017 International Society for Advancement of Cytometry.

Abstract A53: ADAM12 contributes to the malignant potential of pancreatic cancer and may serve as a non-invasive biomarker for its detection

Pancreatic malignancies are the fourth leading cause of all cancer-related deaths of both men and women in the United States. A majority of patients with pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors (pNET) present with advanced disease due to a lack of specific symptoms. The high mortality rate associated with pancreatic cancer can be attributed to both a lack of clinical diagnostic tests for early detection as well as an inadequate understanding of the underlying molecular mechanisms of its aggressive pathogenesis. We have recently become interested in the role that ADAM12 (a disintegrin and metalloprotease 12), a member of the disintegrin metalloprotease family, may play in the development and progression of pancreatic cancer. We have found that ADAM12 protein levels are significantly upregulated in human pancreatic cancer and in mouse models of PDAC and correlate with disease progression. ADAM12 levels were also upregulated in precursor PanIN lesions in a transgenic mouse model. ADAM12 transcript and protein expression is higher in poorly differentiated/quasi-mesenchymal pancreatic cancer cell lines such as Panc1 and MiaPaca2 compared to well-differentiated/classical cell lines such as AspC1 and BxPC3. Downregulation of ADAM12 in pancreatic tumor cells resulted in reduced cell migration, invasion and proliferation whereas apoptotic rates were significantly higher. In agreement with these findings, activation of common signaling pathways including pEGFR, pSTAT3 and pErk were also downregulated in response to ADAM12 silencing in these cells. We have also determined whether ADAM12 could be detected in the urine of patients with pancreatic malignancies and whether ADAM12 levels might serve as an independent predictor of disease status. Retrospective analyses of urine samples (n=130) from PDAC and pNET patients as well as age- and sex-matched controls were conducted. Urinary ADAM12 levels were determined using a monospecific ELISA system. Multivariable logistic regression analyses indicated that, when controlling for age and sex, urinary ADAM12 could serve as significant independent predictor for distinguishing PDAC (P&lt;0.001) and pNET (P&lt;0.008) patients from healthy controls. Kaplan-Meier analysis of estimated patient survival stratified by urinary ADAM12 levels indicated a significantly shorter patient survival time for PDAC patients with high ADAM12 levels (P=0.015) compared to patients with lower urinary ADAM12. Taken together, our results indicate that ADAM12 is aberrantly upregulated in PDAC tumors and contributes to the malignant properties of pancreatic tumor cells. These data also support the conclusion that the measurement of ADAM12 levels may have diagnostic value in detection and/or clinical monitoring of disease status in patients with pancreatic malignancies. [Supported by: The Advanced Medical Research Foundation]

Citation Format: Roopali Roy, Adelle Dagher, David Zurakowski, Matthew Kulke, Marsha A. Moses.{Authors}. ADAM12 contributes to the malignant potential of pancreatic cancer and may serve as a non-invasive biomarker for its detection. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A53.

Abstract 4950: Collagen, type I, alpha 1 (COL1A1): a potential urinary biomarker that can distinguish between benign prostate hyperplasia and localized prostate cancer

Benign prostate hyperplasia (BPH) is the most frequent benign disease among men worldwide and its incidence increases with age. Prostate cancer (PCa) and BPH share similar symptoms and an elevated serum prostate-specific antigen (PSA) can be observed with either benign or malignant growth of the prostate. It is the demographic overlap of BPH and PCa, and the lack of discrimination between these two prostate diseases by PSA, that defines the diagnostic dilemma faced by clinicians when treating prostate disease. The goal of the current study was to identify novel non-invasive, biomarkers that can distinguish between BPH and PCa. We utilized iTRAQ (Isobaric Tags for Relative and Absolute Quantitation) mass spectrometry techniques to sensitively and accurately identify the urinary proteome of men with BPH vs. men with PCa. We then performed functional enrichment analysis and pathways enrichment analysis of these proteins using Ingenuity Pathway Analysis (IPA) tools to determine differentially expressed pathways and functions in PCa as compared to BPH. Network analysis identified differences in a number of signaling molecules including ERK1/2, TGFβ, PI3K, p38 MAPK and NFκB, with a high degree of interactivity. Protein expression was validated by immunoblot analyses using monospecific antibodies. Here, we focused on collagen, type I, alpha 1 (COL1A1), one of a number of extracellular matrix-associated proteins detected. We found that COL1A1 was significantly (P &lt; 0.001) elevated in the urine of patients diagnosed with early or localized PCa but not in the urine of men with BPH. Complementary studies were conducted on human BPH and PCa cells. Our data suggest that COL1A1 may represent a novel non-invasive biomarker that can discriminate between BPH and early PCa. (Supported by The Ellison Foundation)

Citation Format: Andrej Jedinak, Camille Vuichoud, Andrew El-Hayek, Kevin R. Loughlin, Marsha A. Moses. Collagen, type I, alpha 1 (COL1A1): a potential urinary biomarker that can distinguish between benign prostate hyperplasia and localized prostate cancer. [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 4950.

ICAM-1-Targeted, Lcn2 siRNA-Encapsulating Liposomes are Potent Anti-angiogenic Agents for Triple Negative Breast Cancer

Lipocalin 2 (Lcn2) is a promising therapeutic target as well as a potential diagnostic biomarker for breast cancer. It has been previously shown to promote breast cancer progression by inducing the epithelial to mesenchymal transition in breast cancer cells as well as by enhancing angiogenesis. Lcn2 levels in urine and tissue samples of breast cancer patients has also been correlated with breast cancer status and poor patient prognosis. In this study, we have engineered a novel liposomal small interfering RNA (siRNA) delivery system to target triple negative breast cancer (TNBC) via a recently identified molecular target, intercellular adhesion molecule-1 (ICAM-1). This ICAM-1-targeted, Lcn2 siRNA- encapsulating liposome (ICAM-Lcn2-LP) binds human TNBC MDA-MB-231cells significantly stronger than non-neoplastic MCF-10A cells. Efficient Lcn2 knockdown by ICAM-Lcn2-LPs led to a significant reduction in the production of vascular endothelial growth factor (VEGF) from MDA-MB-231 cells, which, in turn, led to reduced angiogenesis both in vitro and in vivo. Angiogenesis (neovascularization) is a requirement for solid tumor growth and progression, and its inhibition is an important therapeutic strategy for human cancers. Our results indicate that a tumor-specific strategy such as the TNBC-targeted, anti-angiogenic therapeutic approach developed here, may be clinically useful in inhibiting TNBC progression.

The GPR 55 agonist, L-α-lysophosphatidylinositol, mediates ovarian carcinoma cell-induced angiogenesis

Background and Purpose

Highly vascularized ovarian carcinoma secretes the putative endocannabinoid and GPR55 agonist, L-α-lysophosphatidylinositol (LPI), into the circulation. We aimed to assess the involvement of this agonist and its receptor in ovarian cancer angiogenesis.

Experimental Approach

Secretion of LPI by three ovarian cancer cell lines (OVCAR-3, OVCAR-5 and COV-362) was tested by mass spectrometry. Involvement of cancer cell-derived LPI on angiogenesis was tested in the in vivo chicken chorioallantoic membrane (CAM) assay along with the assessment of the effect of LPI on proliferation, network formation, and migration of neonatal and adult human endothelial colony-forming cells (ECFCs). Engagement of GPR55 was verified by using its pharmacological inhibitor CID16020046 and diminution of GPR55 expression by four different target-specific siRNAs. To study underlying signal transduction, Western blot analysis was performed.

Key Results

Ovarian carcinoma cell-derived LPI stimulated angiogenesis in the CAM assay. Applied LPI stimulated proliferation, network formation, and migration of neonatal ECFCs in vitro and angiogenesis in the in vivo CAM. The pharmacological GPR55 inhibitor CID16020046 inhibited LPI-stimulated ECFC proliferation, network formation and migration in vitro as well as ovarian carcinoma cell- and LPI-induced angiogenesis in vivo. Four target-specific siRNAs against GPR55 prevented these effects of LPI on angiogenesis. These pro-angiogenic effects of LPI were transduced by GPR55-dependent phosphorylation of ERK1/2 and p38 kinase.

Conclusions and Implications

We conclude that inhibiting the pro-angiogenic LPI/GPR55 pathway appears a promising target against angiogenesis in ovarian carcinoma.

Infantile hemangioma-derived stem cells and endothelial cells are inhibited by class 3 semaphorins

Class 3 semaphorins were discovered as a family of axon guidance molecules, but are now known to be involved in diverse biologic processes. In this study, we investigated the anti-angiogenic potential of SEMA3E and SEMA3F (SEMA3E&F) in infantile hemangioma (IH). IH is a common vascular tumor that involves both vasculogenesis and angiogenesis. Our lab has identified and isolated hemangioma stem cells (HemSC), glucose transporter 1 positive (GLUT1(+)) endothelial cells (designated as GLUT1(sel) cells) based on anti-GLUT1 magnetic beads selection and GLUT1-negative endothelial cells (named HemEC). We have shown that these types of cells play important roles in hemangiogenesis. We report here that SEMA3E inhibited HemEC migration and proliferation while SEMA3F was able to suppress the migration and proliferation in all three types of cells. Confocal microscopy showed that stress fibers in HemEC were reduced by SEMA3E&F and that stress fibers in HemSC were decreased by SEMA3F, which led to cytoskeletal collapse and loss of cell motility in both cell types. Additionally, SEMA3E&F were able to inhibit vascular endothelial growth factor (VEGF)-induced sprouts in all three types of cells. Further, SEMA3E&F reduced the level of p-VEGFR2 and its downstream p-ERK in HemEC. These results demonstrate that SEMA3E&F inhibit IH cell proliferation and suppress the angiogenic activities of migration and sprout formation. SEMA3E&F may have therapeutic potential to treat or prevent growth of highly proliferative IH.

Novel non-invasive biomarkers that distinguish between benign prostate hyperplasia and prostate cancer

Background

The objective of this study was to discover and to validate novel noninvasive biomarkers that distinguish between benign prostate hyperplasia (BPH) and localized prostate cancer (PCa), thereby helping to solve the diagnostic dilemma confronting clinicians who treat these patients.

Methods

Quantitative iTRAQ LC/LC/MS/MS analysis was used to identify proteins that are differentially expressed in the urine of men with BPH compared with those who have localized PCa. These proteins were validated in 173 urine samples from patients diagnosed with BPH (N = 83) and PCa (N = 90). Multivariate logistic regression analysis was used to identify the predictive biomarkers.

Results

Three proteins, β2M, PGA3, and MUC3 were identified by iTRAQ and validated by immunoblot analyses. Univariate analysis demonstrated significant elevations in urinary β2M (P < 0.001), PGA3 (P = 0.006), and MUC3 (P = 0.018) levels found in the urine of PCa patients. Multivariate logistic regression analysis revealed AUC values ranging from 0.618 for MUC3 (P = 0.009), 0.625 for PGA3 (P < 0.008), and 0.668 for β2M (P < 0.001). The combination of all three demonstrated an AUC of 0.710 (95% CI: 0.631 – 0.788, P < 0.001); diagnostic accuracy improved even more when these data were combined with PSA categories (AUC = 0.812, (95% CI: 0.740 – 0.885, P < 0.001).

Conclusions

Urinary β2M, PGA3, and MUC3, when analyzed alone or when multiplexed with clinically defined categories of PSA, may be clinically useful in noninvasively resolving the dilemma of effectively discriminating between BPH and localized PCa.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1284-z) contains supplementary material, which is available to authorized users.

Hypercholesterolemia induces angiogenesis and accelerates growth of breast tumors in vivo

Obesity and metabolic syndrome are linked to an increased prevalence of breast cancer among postmenopausal women. A common feature of obesity, metabolic syndrome, and a Western diet rich in saturated fat is a high level of circulating cholesterol. Epidemiological reports investigating the relationship between high circulating cholesterol levels, cholesterol-lowering drugs, and breast cancer are conflicting. Here, we modeled this complex condition in a well-controlled, preclinical animal model using innovative isocaloric diets. Female severe combined immunodeficient mice were fed a low-fat/no-cholesterol diet and then randomized to four isocaloric diet groups: low-fat/no-cholesterol diet, with or without ezetimibe (cholesterol-lowering drug), and high-fat/high-cholesterol diet, with or without ezetimibe. Mice were implanted orthotopically with MDA-MB-231 cells. Breast tumors from animals fed the high-fat/high-cholesterol diet exhibited the fastest progression. Significant differences in serum cholesterol level between groups were achieved and maintained throughout the study; however, no differences were observed in intratumoral cholesterol levels. To determine the mechanism of cholesterol-induced tumor progression, we analyzed tumor proliferation, apoptosis, and angiogenesis and found a significantly greater percentage of proliferating cells from mice fed the high-fat/high-cholesterol diet. Tumors from hypercholesterolemic animals displayed significantly less apoptosis compared with the other groups. Tumors from high-fat/high-cholesterol mice had significantly higher microvessel density compared with tumors from the other groups. These results demonstrate that hypercholesterolemia induces angiogenesis and accelerates breast tumor growth in vivo.

Urinary ADAM12 and MMP-9/NGAL complex detect the presence of gastric cancer

Although the early diagnosis of gastric cancer provides the opportunity for curative endoscopic resection, comprehensive screening endoscopy would be invasive and expensive. To date, there is a complete absence of clinically useful gastric cancer biomarkers. With the goal of discovering noninvasive biomarkers for the early diagnosis of gastric cancer, we have conducted a case-control study using urine samples from individuals with gastric cancer versus healthy control samples. Of the enrolled 106 patients from September, 2012 to April, 2013, a cohort of 70 patients composed of 35 patients with gastric cancer and 35 age- and sex-matched healthy controls was analyzed. The gastric cancer group was composed of stage IA of 62.9% (22/35). The urinary levels of MMP-9/NGAL complex (uMMP-9/NGAL) and ADAM12 (uADAM12) were significantly higher in the gastric cancer group compared with the healthy control group as determined by monospecific ELISAs (uMMP-9/NGAL: median, 85 pg/mL vs. 0 pg/mL; P = 0.020; uADAM12: median, 3.35 ng/mL vs. 1.44 ng/mL; P < 0.001). Multivariate analysis demonstrated that both uMMP-9/NGAL and uADAM12 were significant, independent diagnostic biomarkers for gastric cancer. Moreover, MMP-9/NGAL activity was significantly elevated as determined by gelatin zymography. The combination of uMMP-9/NGAL with uADAM12 distinguished between control samples and gastric cancer samples with an AUC of 0.825 (P < 0.001) in an ROC analysis. Significantly, immunohistochemical analyses demonstrated a high coexpression of MMP-9 and NGAL (P < 0.001) and high expression of ADAM12 (P < 0.001) in gastric cancer tissues compared with adjacent normal tissues (N = 35). In summary, uMMP-9/NGAL and uADAM12 are potential noninvasive biomarkers for gastric cancer, including early-stage disease.

The endogenous zinc finger transcription factor, ZNF24, modulates the angiogenic potential of human microvascular endothelial cells

We have previously identified a zinc finger transcription factor, ZNF24 (zinc finger protein 24), as a novel inhibitor of tumor angiogenesis and have demonstrated that ZNF24 exerts this effect by repressing the transcription of VEGF in breast cancer cells. Here we focused on the role of ZNF24 in modulating the angiogenic potential of the endothelial compartment. Knockdown of ZNF24 by siRNA in human primary microvascular endothelial cells (ECs) led to significantly decreased cell migration and invasion compared with control siRNA. ZNF24 knockdown consistently led to significantly impaired VEGF receptor 2 (VEGFR2) signaling and decreased levels of matrix metalloproteinase-2 (MMP-2), with no effect on levels of major regulators of MMP-2 activity such as the tissue inhibitors of metalloproteinases and MMP-14. Moreover, silencing ZNF24 in these cells led to significantly decreased EC proliferation. Quantitative PCR array analyses identified multiple cell cycle regulators as potential ZNF24 downstream targets which may be responsible for the decreased proliferation in ECs. In vivo, knockdown of ZNF24 specifically in microvascular ECs led to significantly decreased formation of functional vascular networks. Taken together, these results demonstrate that ZNF24 plays an essential role in modulating the angiogenic potential of microvascular ECs by regulating the proliferation, migration, and invasion of these cells.

Abstract 892: Potential of urinary MMP-9/NGAL complex as a novel biomarker for the early detection of gastric cancer

The early diagnosis of gastric cancer (GC) provides the opportunity for curative endoscopic resection. However, although endoscopy is a standard diagnostic method for this disease, comprehensive screening endoscopy would be invasive, expensive and could result in significant complications. To date, there is a significant lack of useful GC biomarkers. In fact, serum tumor markers such as CEA and CA19-9 have not been recommended as GC diagnostics due to their low sensitivity and specificity. With the goal of discovering non-invasive biomarkers for the early diagnosis of GC, we have conducted a pilot case-control study utilizing urine samples from individuals with gastric cancer vs. healthy control samples. A cohort of 70 patients composed of 35 patients with gastric cancer and 35 age- and sex-matched healthy controls was analyzed. Baseline clinical characteristics were tightly controlled and no significant differences were noted. Since changes in the microvasculature have been described in the very early stages of GC, we conducted an angiogenesis protein array analysis to identify potential candidate biomarkers. Three proteins, IL-8, PECAM-1, MMP-9, were found to be elevated in the urine of GC patients compared to controls by this method. In confirming the elevated levels of urinary MMP-9 by gelatin zymography, we determined that MMP-9/NGAL complex was also significantly elevated in the GC urines compared to control samples. We therefore tested all samples for the presence of IL-8, PECAM-1, MMP-9 and MMP-9/NGAL complex using monospecific ELISAs. We were able to confirm that urinary levels of MMP-9/NGAL complex were significantly higher in the GC group compared to the healthy control group (Median, 85 pg/ml (IQR, 43-224) vs. 0 pg/ml (IQR, 0-213), respectively, P=0.020). Urinary MMP-9/NGAL complex could distinguish between healthy control samples and GC samples with an area under the curve of 0.657(95%CI, 0.527-0.789) in a receiver operating characteristics analysis. A cut-off value of urinary MMP-9/NGAL complex was established and the statistical performance characteristics of this urinary biomarker were also determined. In summary, urinary MMP-9/NGAL complex emerged as a significant non-invasive biomarker for gastric cancer including early stage disease. Ongoing studies are focused on the large scale validation of these findings.

Citation Format: Takaya Shimjura, Adelle Dagher, Masahide Ebi, Tamaki Yamada, Tomonori Yamada, Takashi Joh, Marsha A. Moses. Potential of urinary MMP-9/NGAL complex as a novel biomarker for the early detection of gastric cancer. [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 892. doi:10.1158/1538-7445.AM2014-892

Abstract 891: Urinary ADAM12 levels detect the presence of pancreatic cancer

Pancreatic malignancies are the fourth leading cause of all cancer-related deaths of both men and women in the United States. Each year, approximately 32,000 new patients are diagnosed with this disease and nearly the same number die from it. A majority of patients with pancreatic malignancies, including both pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumors (pNET) present with advanced disease due to a lack of specific symptoms and current diagnostic limitations, making this disease extremely difficult to detect. The combination of poor prognosis and late presentation of pancreatic cancer patients highlights the urgent need for the development of effective, early detection strategies for this disease. Our laboratory has established a comprehensive biomarker discovery initiative whose objective is to identify proteins present in urine of cancer patients, to determine whether their presence might be relevant to disease status and stage and to validate their diagnostic and prognostic efficacy in large scale clinical trials. In the current study, our goal was to determine whether ADAM12 (a disintegrin and metalloprotease 12) could be detected in the urine of patients with pancreatic malignancies and whether ADAM12 levels might serve as an independent predictor of disease status. Retrospective analyses of urine samples (n=130) from PDAC and pNET patients as well as age- and sex-matched controls were conducted. Urinary ADAM12 levels were determined using a monospecific ELISA system. In addition, ADAM12 protein expression in tumor and normal pancreatic tissues was analyzed via immunohistochemistry (IHC). Multivariable logistic regression analyses indicated that, when controlling for age and sex, urinary ADAM12 could serve as significant independent predictor for distinguishing PDAC (P&lt;0.001) and pNET (P&lt;0.008) patients from healthy controls. Kaplan-Meier analysis of estimated patient survival stratified by urinary ADAM12 levels indicated a significantly shorter patient survival time for PDAC patients with high ADAM12 levels (P=0.015) compared to patients with lower urinary ADAM12. In addition, IHC analysis indicated that ADAM12 protein expression was upregulated ∼4-fold in Grade I-III PDAC compared to normal pancreatic tissue. Taken together, our results suggest that the measurement of ADAM12 levels may have diagnostic value in detection and/or clinical monitoring of disease status in patients with pancreatic malignancies. [Supported by: The Advanced Medical Foundation]

Citation Format: Roopali Roy, David Zurakowski, Matthew Kulke, Marsha A. Moses. Urinary ADAM12 levels detect the presence of pancreatic cancer. [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 891. doi:10.1158/1538-7445.AM2014-891