Learning hand in hand: Engaging in research-practice partnerships to advance developmental science

Developmental science research often involves research questions developed by academic teams, which are tested within community or educational settings. In this piece, we outline the importance of research-practice partnerships, which involve both research and practice-based partners collaborating at each stage of the research process. We articulate challenges and benefits of these partnerships for developmental science research, identify relevant research frameworks that may inform these partnerships, and provide an example of an ongoing research-practice partnership.

Abstract IA15: Modeling the tumor microenvironment of high-grade serous ovarian cancer

Using biopsies of metastatic high-grade serous ovarian cancer (HGSOC) that ranged from minimal to extensive disease, we defined RNA and protein profiles that evolved with changes in cellularity, architecture, and tissue modulus. This gave new insights into host response to cancer as well as leukocyte, cytokine, and matrisome regulation in the tumor microenvironment (TME). Although we had studied a single metastatic site, we identified an extracellular matrix (ECM) gene expression signature, which we named the matrix index, that significantly associated with increased stiffness and disease score. High matrix index distinguished patients with a shorter overall survival in ovarian and twelve other primary cancers, suggesting a common matrix response to human cancer. We used this “deconstruction” analysis of a human TME to build 3D multicellular cultures of human HGSOC cells, primary omental fibroblasts, mesothelial cells, and adipocytes. These cultures reproduce the prognostic matrix index signature, as confirmed by RNAseq and immunofluorescence, of the human cancer biopsies. Using these 3D models, we can study regulation of the matrisome and cancer cell invasion. Similarly, we have conducted multilevel analysis of orthotopic mouse models of HGSOC metastases with relevant oncogenic mutations. This analysis identified significant correlations between the transcriptome, host cell infiltrates, immune response, matrisome, vasculature, and tissue modulus of mouse and human TMEs, with several stromal and malignant cell targets in common. However, each mouse model showed distinct differences and potential vulnerabilities that enabled us to predict response to chemotherapy and an anti-IL-6 antibody. The transcriptional profiles of the mouse tumors that differed in chemotherapy response were able to classify chemotherapy-sensitive and -refractory patient tumors. We believe that these 3D human and mouse models provide useful preclinical tools and may help identify subgroups of HGSOC patients most likely to respond to specific therapies.

Citation Format: Frances Balkwill. Modeling the tumor microenvironment of high-grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr IA15.

Pituitary tumour fibroblast-derived cytokines influence tumour aggressiveness

Tumour-associated fibroblasts (TAFs) are key elements of the tumour microenvironment, but their role in pituitary neuroendocrine tumours (PitNETs) has been little explored. We hypothesised that TAF-derived cytokines may play a role in tumour aggressiveness and that their release can be inhibited by somatostatin analogues. TAFs were isolated and cultured from 16 PitNETs (11 clinically non-functioning tumours and 5 somatotropinomas). The fibroblast secretome was assessed with a 42-plex cytokine array before and after multiligand somatostatin receptor agonist pasireotide treatment. Angiogenesis and epithelial-to-mesenchymal transition pathway assessment included CD31, E-cadherin and ZEB1 expression. GH3 cells treated with TAF- or skin fibroblast-conditioned medium were assessed for migration, invasion and cell morphology changes. PitNET TAFs secreted significant amounts of cytokines including CCL2, CCL11, VEGF-A, CCL22, IL-6, FGF-2 and IL-8. TAFs from PitNETs with cavernous sinus invasion secreted higher IL-6 levels compared to fibroblasts from non-invasive tumours (P = 0.027). Higher CCL2 release from TAFs correlated with more capillaries (r = 0.672, P = 0.004), and TAFs from PitNETs with a higher Ki-67 tended to secrete more CCL2 (P = 0.058). SST1 is the predominant somatostatin receptor in TAFs, and pasireotide decreased TAF-derived IL-6 by 80% (P < 0.001) and CCL2 by 35% (P = 0.038). GH3 cells treated with TAF-conditioned medium showed increased migration and invasion compared to cells treated with skin fibroblast-conditioned medium, with morphological and E-cadherin and ZEB1 expression changes suggesting epithelial-to-mesenchymal transition. TAF-derived cytokines may increase PitNET aggressiveness, alter angiogenesis and induce epithelial-to-mesenchymal transition changes. Pasireotide's inhibitory effect on TAF-derived cytokines suggest that this effect may play a role in its anti-tumour effects.

Chemokines modulate the tumour microenvironment in pituitary neuroendocrine tumours

Non-tumoural cells within the tumour microenvironment (TME) influence tumour proliferation, invasiveness and angiogenesis. Little is known about TME in pituitary neuroendocrine tumours (PitNETs). We aimed to characterise the role of TME in the aggressive behaviour of PitNETs, focusing on immune cells and cytokines. The cytokine secretome of 16 clinically non-functioning PitNETs (NF-PitNETs) and 8 somatotropinomas was assessed in primary culture using an immunoassay panel with 42 cytokines. This was correlated with macrophage (CD68, HLA-DR, CD163), T-lymphocyte (CD8, CD4, FOXP3), B-lymphocyte (CD20), neutrophil (neutrophil elastase) and endothelial cells (CD31) content, compared to normal pituitaries (NPs, n = 5). In vitro tumour-macrophage interactions were assessed by conditioned medium (CM) of GH3 (pituitary tumour) and RAW264.7 (macrophage) cell lines on morphology, migration/invasion, epithelial-to-mesenchymal transition and cytokine secretion. IL-8, CCL2, CCL3, CCL4, CXCL10, CCL22 and CXCL1 are the main PitNET-derived cytokines. PitNETs with increased macrophage and neutrophil content had higher IL-8, CCL2, CCL3, CCL4 and CXCL1 levels. CD8+ T-lymphocytes were associated to higher CCL2, CCL4 and VEGF-A levels. PitNETs had more macrophages than NPs (p < 0.001), with a 3-fold increased CD163:HLA-DR macrophage ratio. PitNETs contained more CD4+ T-lymphocytes (p = 0.005), but fewer neutrophils (p = 0.047) with a 2-fold decreased CD8:CD4 ratio. NF-PitNETs secreted more cytokines and had 9 times more neutrophils than somatotropinomas (p = 0.002). PitNETs with higher Ki-67 had more FOXP3+ T cells, as well as lower CD68:FOXP3, CD8:CD4 and CD8:FOXP3 ratios. PitNETs with "deleterious immune phenotype" (CD68^hiCD4^hiFOXP3^hiCD20^hi) had a Ki-67 ≥ 3%. CD163:HLA-DR macrophage ratio was positively correlated with microvessel density (p = 0.015) and area (p < 0.001). GH3 cell-CM increased macrophage chemotaxis, while macrophage-CM changed morphology, invasion, epithelial-to-mesenchymal transition and secreted cytokines of GH3 cells. PitNETs are characterised by increased CD163:HLA-DR macrophage and reduced CD8:CD4 and CD8:FOXP3 T cell ratios. PitNET-derived chemokines facilitate macrophage, neutrophil and T cell recruitment into the tumours which can determine aggressive behaviour.

Abstract 1103: The effects of neo-adjuvant chemotherapy on myeloid cells in high-grade serous ovarian cancer metastases

Many tumours have abundant macrophage populations. Tumour-associated macrophages (TAMs) frequently have tumour promoting roles and are associated with poor clinical outcome. We hypothesise that targeting TAMs in high-grade serous ovarian cancer (HGSOC) may improve response to chemotherapy.

We have assessed the effects of chemotherapy on TAM populations in human HGSOC obtained pre- and post-chemotherapy as well as in murine HGSOC models harbouring a relevant mutational profile. We find that chemotherapy treatment decreases TAM density within tumour areas. Furthermore, TAMs expressing markers known to associate with disease progression were decreased following chemotherapy. In vivo and in vitro we have demonstrated an up-regulation of inflammasome activation and TLR signalling in live myeloid cells following chemotherapy and have shown that macrophages are killed by chemotherapy at clinically relevant drug concentrations. These observations suggest a mechanism for TAM depletion and highlight chemotherapy induced activation of innate immunity in HGSOC.

The majority of HGSOC patients respond well to first line chemotherapy but will relapse and succumb to treatment resistant disease. We have developed a murine model of HGSOC relapse after first-line chemotherapy, which has the potential to extend translational studies into this clinically important area. We have found that TAMs are re-established in tumours at relapse, suggesting a clinically defined window of opportunity to target TAMs in HGSOC following first-line chemotherapy.

Overall, our results provide a rationale for targeted re-programming of TAMs in HGSOC after chemotherapy.

Citation Format: Owen M. Heath, Eleni Maniati, Chiara Belato, Ganga Gopinathan, Laura Lecker, Anissa Lakhani, Colin Pegrum, Jacqueline McDermott, Michelle Lockley, Desmond P. Barton, Frances Balkwill. The effects of neo-adjuvant chemotherapy on myeloid cells in high-grade serous ovarian cancer metastases [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 1103.

MON-460 Pasireotide Treatment Inhibits Cytokine Release from Pituitary Adenoma-Associated Fibroblasts: Is This Mechanism Playing a Key Role in Its Effect?

Introduction: Tumour-associated fibroblasts (TAFs) are important elements of the tumour microenvironment (TME) well-studied in several cancers, but their role in pituitary adenomas (PAs) has never been shown. We aimed to study the role of TAFs in PAs and its response to somatostatin analogues (SSA). Methods: TAFs were isolated from 11 freshly-cultured NFPAs and 5 GHomas as confirmed by vimentin and αSMA immunostaining. TAF presence in PAs was confirmed by immunohistochemistry, and further assessed with the gene-signature based method xCELL on a different set of samples. Macrophage infiltration, angiogenesis and epithelial-to-mesenchymal pathways were evaluated by immunohistochemistry for CD68, CD163, HLA-DR, E-cadherin, ZEB1 and CD31. TAFs secretome was assessed in vitro on culture supernatants, at baseline and after treatment with pasireotide (10^-7M) using Millipore MILLIPLEX human cytokine 42-plex. GH3 cells were treated with TAF-conditioned media (CM) and normal skin fibroblasts-CM (F-CM). Cell morphology (analysed by ImageJ), invasion and epithelial-to-mesenchymal pathways were assessed. Results: CCL2 and eotaxin-1 were identified as the top secreted cytokines in TAF supernatants, followed by VEGF-A, CCL22, IL-6, FGF-2 and IL-8. TAF secretomes from NFPAs and GHomas did not differ significantly. PAs with cavernous sinus invasion had higher TAF-derived IL-6 levels compared to non-invasive PAs (72.7±10.7 vs 43.9±6.3pg/mL; p=0.027), while there was a trend for TAFs from PAs with higher Ki67 to secrete more CCL2 (p=0.058). Correlation between macrophages and TAF-derived FGF-2 was found (r=0.499, p=0.049), and increased FGF-2 and CXCL1 levels were seen in PAs with a macrophage M2:M1 ratio≥2. CCL2 levels were correlated with microvessel area (r=0.672, p=0.004), whereas PDGF-AA was negatively correlated with E-cadherin immunoreactivity (r=-0.564, p=0.023). RT-qPCR analyses indicated that the sst1 receptor is the predominant somatostatin receptor expressed in TAFs, while sst2 and sst5 receptors are poorly expressed. Pasireotide treatment decreased TAF-derived IL-6 by 80% (p<0.001) and CCL2 by 35% (p=0.038). GH3 cells treated with TAF-CM showed epithelial-to-mesenchymal-like morphology and increased invasiveness in comparison to F-CM or untreated cells, as well as E-cadherin downregulation and ZEB1 upregulation. Conclusions: TAFs are present in the TME of PAs and display a biological role. TAF-derived cytokines may influence tumor and non-tumoral cells (such as macrophages) leading to increased invasiveness, as well as influence angiogenesis and epithelial-to-mesenchymal pathways in PAs, with IL-6 and CCL2 emerging as relevant mediators. The inhibitory effect of pasireotide on TAF secretome highlights a promising anti-tumoral effect of SSAs by directly targeting TAFs and thus modulating the TME in PAs.

MON-462 Cytokine Network in Pituitary Adenomas and Its Role in the Tumor Microenvironment: Focus on Macrophages

Introduction: Cytokines are important elements of the tumor microenvironment (TME) coordinating host responses against the tumor, promoting growth, invasion, angiogenesis and regulating non-tumoral cells in TME. Little is known regarding the cytokine network in pituitary adenomas (PAs) and its role in the TME. We aimed to characterise PA-derived cytokines to study their role in the TME of PAs. Methods: The cytokine secretome of culture supernatants from 27 human PAs (16 NFPAs, 9 GHomas, 1 TSHoma, 1 ACTHoma) was assessed using Millipore MILLIPLEX cytokine/chemokine 42-plex. IL-8 and CCL2 expression was further studied by RNAscope. Angiogenesis, macrophages and epithelial-to-mesenchymal transition were evaluated by immunohistochemistry for CD31, CD68, CD163, HLA-DR, E-cadherin and ZEB1. Macrophage infiltration in PAs and its phenotype was further assessed with the gene-signature based method xCELL. We have developed an in vitro model of pituitary cells (GH3) and macrophages (RAW264.7) and studied their interaction via assessing the effect of conditioned media. We documented cell morphology (ImageJ), migration and invasion (Boyden chambers), epithelial-to-mesenchymal transition pathway (RT-qPCR and immunocytochemistry) and secretome changes (cytokine array). Results: IL-8, CCL2, CCL3 and CCL4 are the main PA-derived cytokines, with CXCL1, CXCL10, CCL22 and CX3CL1 also secreted by most of these tumors. RNAscope data showed that CCL2 and IL-8 are mainly synthesised in the pituitary tumour cells. NFPAs secreted more cytokines than somatotropinomas, especially CCL2 (16x more), IL-8 (25x more) and CCL4 (27x more). PAs contained more macrophages than normal pituitary (4.9±0.7 vs 1.2±0.2%, p=0.007). Macrophage infiltration was associated with higher chemokine levels (CCL2, CCL3, CCL4, CXCL1 and IL-8). Macrophages in PAs belong to the CD163+ M2-subtype, while in normal pituitary M1-macrophages predominate, resulting in 3-fold increased M2:M1 ratio in PAs (p<0.001). These findings were confirmed with xCELL on a different set of PA samples. M2:M1 ratio correlated with microvessel density (r=0.509; p=0.008). Macrophage-conditioned media induced numerous effects on GH3 cells: more elongated, epithelial-to-mesenchymal transition-like cells, significantly increased migration and invasiveness, and altered GH3 cell cytokine secretome. On other hand, GH3 cell-conditioned media induced activation-associated morphological changes in RAW264.7 macrophages, increased chemotaxis and altered macrophage cytokine secretome. Conclusions: Primarily M2-subtype macrophages are present in the TME of PAs and their number is correlating with CCL2, IL-8, CCL3 and CCL4 release. NFPAs secrete higher levels of cytokines than somatotropinomas. Our data suggest that there is crosstalk between pituitary tumor cells and macrophages which may determine the biological behavior of PAs.

Abstract PR14: CRISPR/Cas9-mediated Trp53, Brca1, Brca2, Pten, and Nf1 knockout to generate improved murine models of ovarian high-grade serous carcinoma

Background: Transplantable murine models of ovarian high-grade serous carcinoma (HGSC) that recreate key mutations seen in the human disease are greatly needed. These models would assist investigation of the relationships between tumor genotype, chemotherapy response, and immune microenvironment. ID8 is a widely-used murine model of ovarian cancer. However, we previously showed that it is poorly characteristic of HGSC, with no functional alterations in key HGSC genes including Trp53, Brca1, Brca2, Pten, Nf1, and Rb1. We generated novel ID8 derivatives with single (Trp53-/-) and double (Trp53-/-;Brca2-/-) mutations using CRISPR/Cas9 gene editing.

Methods: We have now generated further ID8 derivatives: Trp53-/-;Brca1-/-, Trp53-/-;Pten-/- and Trp53-/-;Nf1-/-. In vitro, we assessed DNA double-strand break repair, and sensitivity to both platinum chemotherapy and PARP inhibition, as well as cytokine and chemokine production. In vivo, we investigated intraperitoneal growth, as well as immune cell infiltration into the tumor microenvironment.

Results: Assays of homologous recombination (HR) function confirm that loss of Brca1 function, but not Pten or Nf1, renders cells HR defective. This is accompanied by significant increases in sensitivity to both platinum and the PARP inhibitor rucaparib in Trp53-/-;Brca1-/- cells compared to Trp53-/-. Drug sensitivity in Trp53-/-;Pten-/- and Trp53-/-;Nf1-/- cells remains unchanged compared to Trp53-/- cells.

In vivo, loss of Pten and Nf1 significantly reduced time to reach humane endpoints following intraperiteonal injection (34 and 36.5 days respectively) compared to p53 loss alone (46 days, both p&lt;0.0001), while Brca1 loss had no effect on intraperitoneal growth (47 days).

There were significant differences in survival for the different genotypes following three doses of intraperitoneal cisplatin (5mg/kg on days 28, 35, and 42 only). Mice bearing control Trp53-/- tumors reached humane endpoint in a median of 81 days. Trp53-/-;Pten-/- and Trp53-/-;Nf1-/- tumors produced the worst survival (median 69 and 71 days, respectively; p&lt;0.01 for both compared to Trp53-/-). Survival was extended to 97 days for Trp53-/-;Brca1-/- (p=0.0003 compared to Trp53-/-), but even further to 113 days for Trp53-/-;Brca2-/- tumors (median 113 days), which was significantly longer than both Trp53-/- and Trp53-/-;Brca1-/- (p&lt;0.0001 for both).

In poor-prognosis Trp53-/-;Pten-/- and Trp53-/-;Nf1-/- tumors, whole-blood analysis of mice at endpoint shows a significant decrease in haemoglobin compared to single Trp53-/- tumors (p=0.0023). Furthermore, flow cytometry data show a significant increase in CD11b+;Ly6CG++ neutrophils in the ascites of mice compared to single Trp53-/-, suggesting an immunosuppressive microenvironment (p=0.0146). Analysis of whole blood at endpoint again shows a significant increase in neutrophils in mice bearing double Trp53-/-;Pten-/- tumors compared to single Trp53-/- (p=0.0203). Possible mechanisms suggested from cytokine array data include increased expression of CCL7 in Trp53-/-;Pten-/- cells, which is confirmed in tumors. Further work to characterize T-cell activation in these models is ongoing.

Conclusions: These novel ID8 models represent a new and simple tool to investigate the biology of HGSC. All cells will be made available to other researchers upon request.

This abstract is also being presented as Poster B61.

Citation Format: Josephine Walton, Malcolm Farquharson, Susan Mason, Julianna Blagih, Darren Ennis, Elaine Leung, Suzanne Dowson, Dimitris Athineos, Damiano Rami, David Stevenson, Seth Coffelt, Karen Blyth, Douglas Strathdee, Frances Balkwill, Karen Vousden, Michelle Lockley, Iain McNeish. CRISPR/Cas9-mediated Trp53, Brca1, Brca2, Pten, and Nf1 knockout to generate improved murine models of ovarian high-grade serous carcinoma. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr PR14.

Abstract A31: Mutant p53 increases integrin-ECM interactions in early HGSOC

Until recently, it was thought that high-grade serous ovarian cancer (HGSOC) arises from the ovarian surface epithelium (OSE). Now, it has become clear that the epithelium of the fallopian tube fimbriae is the starting point of many HGSOCs. Serous tubal intraepithelial carcinomas (STICs) are suggested to be the earliest form of HGSOC and show mutations in the p53 gene. Part of the neoplastic transformation into invasive HGSOC may be the initial adhesion of STIC cells to the surface of the ovary as a first site of metastasis. To examine the role of mutant p53 immortalized fallopian tube secretory epithelial (FTSE) cells in the early onset of HGSOC, we used mechanically tunable hydrogels and developed a protocol to obtain decellularized human ovary scaffolds for 3D cell cultures. Stable expression of mutant p53 in FTSE cells promoted adhesion to hydrogel matrices and invasion into decellularized ovary scaffolds. Next, we sought to analyze the extracellular matrix (ECM) landscape of human fallopian tube and ovary tissues and identified proteins with a high affinity to integrin αvβ3. Mutant p53 FTSE cells had increased levels of integrin αvβ3 and decreased adhesive potential upon integrin αvβ3 blockage compared to wild-type FTSE cells. The results indicate that FTSE cells expressing mutant p53 upregulate integrin expression, which in turn alters their tissue-specific ECM interactions. Our findings give new insights in the early onset of HGSOC and may help to understand the role of p53 in the cells of origin of HGSOC.

Citation Format: Laura SM Lecker, Caterina Trevisan, Robin Delaine-Smith, Eleni Maniati, Oliver Pearce, Christoph Meinert, Marcin Iwanicki, Ronny Drapkin, Daniela Loessner, Frances Balkwill. Mutant p53 increases integrin-ECM interactions in early HGSOC. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A31.

A guiding map for inflammation

Biologists, physicians and immunologists have contributed to the understanding of the cellular participants and biological pathways involved in inflammation. Here, we provide a general guide to the cellular and humoral contributors to inflammation as well as to the pathways that characterize inflammation in specific organs and tissues.

Upregulation of amphiregulin on CD14++CD16- (classical) monocytes in non-small cell lung cancer

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Background: Amphiregulin is an EGFR ligand which contributes to many of the hallmarks of cancer including angiogenesis and metastasis. Recent studies demonstrate that Amphiregulin promotes an immunosuppressive tumour microenvironment by modulating the expression of T regulatory cells. Although its expression has been described on a variety of immune cells and tumour cells, there is no published data on Amphiregulin expression by monocytes to date. Previous work by this group has demonstrated that monocytes from non-small cell lung cancer patients are phenotypically and genomically different compared to healthy volunteers. This study aims to further investigate the differing genomic profile of monocytes in non-small cell lung cancer. Methods: Gene expression profiling was performed on CD14++CD16- (classical) monocytes of newly diagnosed patients with Stage IV non-small cell lung cancer (n = 6) and age-matched healthy volunteers (n = 6) using Affymetrix Human U133 Plus 2.0 array. Validation of differentially expressed genes of interest (including Amphiregulin) at mRNA level was performed using real-time PCR with TaqMan gene expression assays on independent patient (n = 6) and healthy volunteer cohorts (n = 6). Differential protein expression of Amphiregulin from the monocytes of healthy volunteers (n = 3) and non-small cell lung cancer patients (n = 3) was validated using ELISA technology. Results: Amphiregulin is one of the most upregulated genes on classical monocytes in non-small cell lung cancer patients compared to healthy volunteers (p = 0.001). The increased expression of Amphiregulin was confirmed on qPCR validation in an independent cohort of non-small cell lung cancer patients (p < 0.05) as well as in the original group (p < 0.001). Amphiregulin was also found to be increased at protein level on CD14++CD16- monocytes of non-small cell lung cancer compared to healthy volunteers. (p = 0.37). Conclusions: Amphiregulin is overexpressed by classical monocytes in non-small cell lung cancer and this over-expression is confirmed at mRNA and protein level. The production of Amphiregulin has not been ascribed to human monocytes in non-small cell lung cancer making its overexpression in this study a unique finding.

CXCR2 Inhibition Profoundly Suppresses Metastases and Augments Immunotherapy in Pancreatic Ductal Adenocarcinoma

CXCR2 has been suggested to have both tumor-promoting and tumor-suppressive properties. Here we show that CXCR2 signaling is upregulated in human pancreatic cancer, predominantly in neutrophil/myeloid-derived suppressor cells, but rarely in tumor cells. Genetic ablation or inhibition of CXCR2 abrogated metastasis, but only inhibition slowed tumorigenesis. Depletion of neutrophils/myeloid-derived suppressor cells also suppressed metastasis suggesting a key role for CXCR2 in establishing and maintaining the metastatic niche. Importantly, loss or inhibition of CXCR2 improved T cell entry, and combined inhibition of CXCR2 and PD1 in mice with established disease significantly extended survival. We show that CXCR2 signaling in the myeloid compartment can promote pancreatic tumorigenesis and is required for pancreatic cancer metastasis, making it an excellent therapeutic target.

Centre of the Cell: Science Comes to Life

Centre of the Cell is a unique biomedical science education centre, a widening participation and outreach project in London's East End. This article describes Centre of the Cell's first five years of operation, the evolution of the project in response to audience demand, and the impact of siting a major public engagement project within a research laboratory.

Abstract 455: B cells actively participate to the anti-cancer immune response in high grade serous ovarian cancer metastases

Intra-tumor B cells and immunoglobulin signatures have been associated with a better clinical prognosis in ovarian cancer (Iglesia et al, 2014; Nielsen et al, 2012). However little is known about the mechanisms by which B cells influence the anti-cancer immune response. The aim of our research is to evaluate B cell dependent anti-cancer immune responses in peritoneal metastases in high grade serous ovarian cancer (HGSOC) patients.

We have found that in these peritoneal metastases, B cells are mainly located in lymphoid structures and a high proportion of these (60%) display a CD27+ memory phenotype. HGSOC B cells are able to secrete Th1 related cytokines as well as high levels of IL8, which is a chemo-attractant for T cells, granulocytes and macrophages. Interestingly CD4+ and CD8+ T cells express high levels of the IL8 receptor, CXCR1, which suggests B cells help recruiting T cells to lymphoid structures.

Plasma cells were also detected in the peritoneal metastases along with IgG deposits. Secreted IgGs were mainly located in stromal areas suggesting that the associated matrix may prevent their infiltration into tumour islets and/or that they target specific stromal antigens.

Interestingly, we observed that neoadjuvant chemotherapy and residual disease after chemotherapy influence the type of IgG subclasses expressed in the omentum of HGSOC patients. Chemotherapy enhances the expression of IgG1, IgG2 and IgG3 immunoglobulins in omentum with residual disease. This supports the notion that B cells are involved in the anti-tumor immune response in HGSOC metastases.

In conclusion, our data suggest that B cells actively participate to the anti-tumor immune response in HGSOC metastases. This response is preferentially Th1 oriented through the production of cytokines and dominant expression of IgG1 immunoglobulins. Enhancing the B cell dependent anti-tumor immune response could be a potential strategy for the treatment of HGSOC patients.

Iglesia MD, Vincent BG, Parker JS, Hoadley KA, Carey LA, Perou CM, Serody JS (2014) Prognostic B-cell signatures using mRNA-seq in patients with subtype-specific breast and ovarian cancer. Clin Cancer Res 20: 3818-3829

Nielsen JS, Sahota RA, Milne K, Kost SE, Nesslinger NJ, Watson PH, Nelson BH (2012) CD20+ tumor-infiltrating lymphocytes have an atypical CD27- memory phenotype and together with CD8+ T cells promote favorable prognosis in ovarian cancer. Clin Cancer Res 18: 3281-3292

Citation Format: Anne Montfort, Steffen Boehm, Thomas Dowe, Joanne Topping, Michelle Lockley, Melania Capasso, Frances Balkwill. B cells actively participate to the anti-cancer immune response in high grade serous ovarian cancer metastases. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 455. doi:10.1158/1538-7445.AM2015-455

Interleukin-6 Stimulates Defective Angiogenesis

The cytokine IL6 has a number of tumor-promoting activities in human and experimental cancers, but its potential as an angiogenic agent has not been fully investigated. Here, we show that IL6 can directly induce vessel sprouting in the ex vivo aortic ring model, as well as endothelial cell proliferation and migration, with similar potency to VEGF. However, IL6-stimulated aortic ring vessel sprouts had defective pericyte coverage compared with VEGF-stimulated vessels. The mechanism of IL6 action on pericytes involved stimulation of the Notch ligand Jagged1 as well as angiopoietin2 (Ang2). When peritoneal xenografts of ovarian cancer were treated with an anti-IL6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies, there was an association between levels of IL6 mRNA, Jagged1, and Ang2. Our findings have implications for the use of cancer therapies that target VEGF or IL6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease, and stroke.

B regulatory cells in cancer

B regulatory cells are a newly described subpopulation of B cells that appear to play important roles in autoimmunity and more recently, in cancer. In this review we summarize our current knowledge of B regulatory cells, as well as the body of evidence pointing towards a role for B cells in general, and B regulatory cells in particular, in promoting tumor growth.

Abstract 4391: CD20 as a target for therapy in solid tumors

Using the K14-HPV16 mouse model of squamous carcinogenesis (SCC), we previously reported that B cells foster neoplastic progression through deposition of immunoglobulin complexes in premalignant tissue via Fcα receptor-dependent activation of recruited myeloid cells. Here we evaluated therapeutic interventions targeting these pathways in preclinical trials through administration of depleting αCD20 antibody and small molecule inhibitor of Syk kinase. Both approaches harbored efficacy in preventing premalignant progression to the dysplastic/carcinoma in situ state. Screening a diverse spectrum of human solid tumors revealed SCCs of the vulva, head and neck, as well as pancreatic ductal adenocarcinomas (PDAC) as scoring positively for “signatures” of B cell or plasma cell infiltration, i.e. Ig or CD20 mRNA expression, thereby identifying carcinomas potentially amenable to anti-B cell therapies. Accordingly, B cell-deficient mice failed to support growth of either transplantable orthotopic SCC or PDAC. While administration of αCD20 mAB as a single agent was inefficient in impeding growth of preexisting SCCs, when delivered in combination with cytotoxic chemotherapy, e.g., paclitaxel, carboplatin or cisplatin, αCD20 mAb significantly improved chemotherapeutic response and improved survival by a mechanism dependent on CD8+ T cells. These data reveal that blocking protumorigenic programs regulating by humoral immunity, in combination with chemotherapy, effectively reprograms the tumor immune microenvironment and improves outcome. The authors acknowledge generous support from the NIH/NCI (R01CA130980, R01CA13256, R01CA140943, R01CA15531), the Department of Defense (W81XWH-09-1-0342, W81XWH-10-BCRP-EOHS-EXP) and the Susan G Komen Foundation (KG111084)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4391. doi:1538-7445.AM2012-4391

Abstract 49: Targeting the TNF network in human ovarian cancer - A systems biology approach

In a recent publication (Kulbe et al Cancer Res 2011 epub ahead of print), we have shown how key pathways in cancer-related inflammation and Notch signaling are part of an autocrine malignant cell network in high-grade serous ovarian cancer, HGSOC. This network, that we have named the TNF network, has paracrine actions on angiogenesis, the stromal signature and the immune cell infiltrate in HGSOC. We have now used a systems biology approach, combining data from phospho-proteomic mass spectrometry and gene expression array analysis, to define the best therapeutic targets within the network and to identify drugs that may synergise with cytokine and chemokine inhibitors. First, we established a hierarchy of kinases involved in the TNF network and analyzed the constitutively active kinases in one of the high TNF network cell lines. Of 45 constitutively active kinases, 33 of these kinases showed direct interactions with each other. Next, we mapped gene expression microarray data onto the Connectivity Map of drugs in order to identify compounds having an effect on transcription similar to that of the TNF network. Among the identified candidate drugs were luteolin, apigenin and resveratrol. One of the known targets of this class of drugs is the protein kinase Casein kinase II (CSNK2A1), a kinase activated in association with the TNF network. In conclusion, we have identified kinases, particularly CK2, associated with the TNF network that may play a central role in sustaining the cytokine network and/or mediating its effects in ovarian cancer. We believe our findings have implications for our understanding of ovarian cancer biology and the development of new and more effective treatments for this disease.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 49. doi:1538-7445.AM2012-49

Paraneoplastic thrombocytosis in ovarian cancer

BACKGROUND

The mechanisms of paraneoplastic thrombocytosis in ovarian cancer and the role that platelets play in abetting cancer growth are unclear.

METHODS

We analyzed clinical data on 619 patients with epithelial ovarian cancer to test associations between platelet counts and disease outcome. Human samples and mouse models of epithelial ovarian cancer were used to explore the underlying mechanisms of paraneoplastic thrombocytosis. The effects of platelets on tumor growth and angiogenesis were ascertained.

RESULTS

Thrombocytosis was significantly associated with advanced disease and shortened survival. Plasma levels of thrombopoietin and interleukin-6 were significantly elevated in patients who had thrombocytosis as compared with those who did not. In mouse models, increased hepatic thrombopoietin synthesis in response to tumor-derived interleukin-6 was an underlying mechanism of paraneoplastic thrombocytosis. Tumor-derived interleukin-6 and hepatic thrombopoietin were also linked to thrombocytosis in patients. Silencing thrombopoietin and interleukin-6 abrogated thrombocytosis in tumor-bearing mice. Anti-interleukin-6 antibody treatment significantly reduced platelet counts in tumor-bearing mice and in patients with epithelial ovarian cancer. In addition, neutralizing interleukin-6 significantly enhanced the therapeutic efficacy of paclitaxel in mouse models of epithelial ovarian cancer. The use of an antiplatelet antibody to halve platelet counts in tumor-bearing mice significantly reduced tumor growth and angiogenesis.

CONCLUSIONS

These findings support the existence of a paracrine circuit wherein increased production of thrombopoietic cytokines in tumor and host tissue leads to paraneoplastic thrombocytosis, which fuels tumor growth. We speculate that countering paraneoplastic thrombocytosis either directly or indirectly by targeting these cytokines may have therapeutic potential. (Funded by the National Cancer Institute and others.).

Sequential genetic change at the TP53 and chemokine receptor CXCR4 locus during transformation of human ovarian surface epithelium

Early genetic events in the development of high-grade serous ovarian cancer, HGSOC, may define the molecular basis of the profound structural and numerical instability of chromosomes in this disease. To discover candidate genetic changes we sequentially passaged cells from a karyotypically normal hTERT immortalised human ovarian surface epithelial line (IOSE25) resulting in the spontaneous formation of colonies in soft agar. Cell lines (TOSE 1 and 4) established from these colonies had an abnormal karyotype and altered morphology but were not tumorigenic in immunodeficient mice.

TOSE cells showed loss of heterozygosity at TP53, increased nuclear p53 immunoreactivity and altered expression profile of p53 target genes. The parental IOSE25 cells contained a missense, heterozygous R175H mutation in TP53 whereas TOSE cells had loss of heterozygosity at the TP53 locus with a new R273H mutation at the previous wild-type TP53 allele.

Cytogenetic and array CGH analysis of TOSE cells also revealed a focal genomic amplification of CXCR4, a chemokine receptor commonly expressed by HGSOC cells. TOSE cells had increased functional CXCR4 protein and its abrogation reduced epidermal growth factor receptor, EGFR, expression, as well as colony size and number. The CXCR4 ligand, CXCL12, was epigenetically silenced in TOSE cells and its forced expression increased TOSE colony size. TOSE cells had other cytogenetic changes typical of those seen in HGSOC ovarian cancer cell lines and biopsies. In addition, enrichment of CXCR4 pathway in expression profiles from HGSOC correlated with enrichment of a mutated TP53 gene expression signature and of EGFR pathway genes.

Our data suggest that mutations in TP53 and amplification of the CXCR4 gene locus may be early events in the development of HGSOC, and associated with chromosomal instability.

IL6-STAT3-HIF signaling and therapeutic response to the angiogenesis inhibitor sunitinib in ovarian clear cell cancer

PURPOSE

Ovarian clear cell adenocarcinoma (OCCA) is an uncommon histotype that is generally refractory to platinum-based chemotherapy. We analyze here the most comprehensive gene expression and copy number data sets, to date, to identify potential therapeutic targets of OCCA.

EXPERIMENTAL DESIGN

Gene expression and DNA copy number were carried out using primary human OCCA tumor samples, and findings were confirmed by immunohistochemistry on tissue microarrays. Circulating interleukin (IL) 6 levels were measured in serum from patients with OCCA or high-grade serous cancers and related to progression-free and overall survival. Two patients were treated with sunitinib, and their therapeutic responses were measured clinically and by positron emission tomography.

RESULTS

We find specific overexpression of the IL6-STAT3-HIF (interleukin 6-signal transducer and activator of transcription 3-hypoxia induced factor) pathway in OCCA tumors compared with high-grade serous cancers. Expression of PTHLH and high levels of circulating IL6 in OCCA patients may explain the frequent occurrence of hypercalcemia of malignancy and thromboembolic events in OCCA. We describe amplification of several receptor tyrosine kinases, most notably MET, suggesting other potential therapeutic targets. We report sustained clinical and functional imaging responses in two OCCA patients with chemotherapy-resistant disease who were treated with sunitinib, thus showing significant parallels with renal clear cell cancer.

CONCLUSIONS

Our findings highlight important therapeutic targets in OCCA, suggest that more extensive clinical trials with sunitinib in OCCA are warranted, and provide significant impetus to the growing realization that OCCA is molecularly and clinically distinct to other forms of ovarian cancer.