bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract C11: The role of immune cells and androgen receptor splice variant 567 exon-skipping in prostate cancer
Authors: Hara Jared HL , Plymate Stephen R. , Sprenger Cynthia T.
Published: October 2016

Importance: Nearly all metastatic prostate cancer treated with first-line androgen deprivation therapies (ADT) will progress to castrate resistant prostate cancer (CRPC). Current ADT treatments and use are associated with upregulation of constitutively active androgen receptor splice variants. Androgen receptor splice variant 567 exon-skipping (ARv567es) is correlated with a marked decrease in 5-year survival in spite of ADT treatment. In our ARv567es mouse models, we have observed a high immune cell infiltrate in places common for mouse prostate cancer metastases such as the lung. Thus, there is an increased need to understand the role of the immune system and ARv567es in prostate cancer metastasis and resistance.

Objective: To understand the role of immune cells in metastasis of prostate cancer expressing splice variants.

Design: M12 human prostate cancer cells transfected with a plasmid containing ARv567es cDNA were grown in vitro and exposed to Bone Marrow Macrophages (BMM) isolated from C57BL/6 mice femurs. BMM were differentiated into M0, M1, and M2 macrophages. M1 macrophages are thought to attack tumor cells while M2 macrophages promote their growth. The following experiments were performed: proliferation studies (MTS assays), migration studies (scratch assays), and invasion studies (Boyden chambers).

Results: Proliferation was significantly higher when M12 ARv567es cells were exposed to M2 conditioned medium as compared to M1 conditioned medium. Scratch assays revealed a significantly increased migration of M12 cells co-cultured with M0 and M2 conditioned medium. Boyden chamber studies demonstrated an increase in migration when M12 cells were exposed to M2 cells.

Conclusions and relevance: We demonstrate in vitro evidence to support the current hypothesis of the role of the immune system in prostate cancer metastasis. Overall, our results demonstrate that immune cells, including M2 macrophages, may create a tumor microenvironment that promotes prostate cancer metastasis.

Citation Format: Jared HL Hara, Stephen R. Plymate, Cynthia T. Sprenger. The role of immune cells and androgen receptor splice variant 567 exon-skipping in prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C11.
Abstract C14: Foxf1 transcription factor reprograms pulmonary endothelial cells to promote metastasis
Authors: Cai Yuqi , Le Tien , Malewski David , Bolte Craig , Goda Chinmayee , Kalin Tanya V.
Published: October 2016

The ability to form a metastatic niche is a unique feature of tumor cells. The niche provides signals for tumor cells extravasation, survival, dormancy or proliferation, ultimately leading to the formation of metastasis. Endothelial cells of metastatic niche become activated and play a key role in tumor cells extravasation and establishing inflammatory microenvironment that supports metastatic outgrowth. Although multiple signaling pathways have been implicated in formation of metastatic niche, the transcriptional network which controls reprogramming of normal endothelial cells (EC) into activated endothelial cells of the metastatic niche (aEC) are poorly understood. Screening for multiple regulators of the endothelial reprogramming, we identified Forkhead Box F1 (Foxf1) transcription factor, which is highly expressed in normal pulmonary ECs and is down-regulated in aECs within mouse and human lung metastases. Tamoxifen-regulated inactivation of both Foxf1 alleles in EC of adult Pdgfb-CreER/Foxf1fl/fl mice caused lung inflammation and edema, leading to respiratory insufficiency and uniform mortality. Deletion of a single Foxf1 allele from mouse ECs was sufficient to increase the number and size of pulmonary metastases in the spontaneous orthotopic mouse model of breast cancer. Increased lung metastasis in Foxf1-deficient mice was associated with increased recruitment of macrophages to the metastatic niche. The genomic signature of Foxf1 deletion from purified lung ECs indicated increased expression of cell adhesion molecules and pro-inflammatory chemokines, as well as reduced expression of genes critical for maintenance of adherence junctions in ECs. Foxf1 knockdown in vitro and in vivo disrupted adherence junctions, increased endothelial permeability and decreased mRNA and protein levels of VE-cadherin, a key regulator of endothelial barrier function. Foxf1 directly bound to and induced transcriptional activity of the VE-cadherin (Cdh5) promoter through -788/-775 bp Cdh5 promoter region. Altogether, Foxf1 transcription factor controls reprogramming of normal pulmonary ECs into aECs of the metastatic niche by regulating expression of endothelial genes critical for recruitment of macrophages and extravasation of tumor cells through endothelial barrier.

Citation Format: Yuqi Cai, Tien Le, David Malewski, Craig Bolte, Chinmayee Goda, Tanya V. Kalin. Foxf1 transcription factor reprograms pulmonary endothelial cells to promote metastasis. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C14.
Abstract C24: Beyond EMT: Vimentin function in lung cancer metastasis
Authors: Salgueiro Alessandra M. , Gilbert-Ross Melissa , Havel Lauren S. , Shupe John , Koyen Allyson E. , Grossniklaus Hans E. , Sica Gabriel , Marcus Adam I.
Published: October 2016

Vimentin is an intermediate filament protein that has been used in the clinic as a biomarker for metastatic potential and poor patient prognosis across numerous solid tumor types; however, little is known about how vimentin might contribute to cancer progression and metastasis. Here we created a novel genetically engineered mouse model (GEMM) to study the role of vimentin in lung cancer progression and metastasis. We first re-developed an LSL-KrasG12D,LKB1fl/fl mouse model whereby intranasal administration of lentiviral Cre recombinase causes a KrasG12D mutation and LKB1 knockout in the lungs. In this model Kras/Lkb1 GEMM (termed KLV+/+), approximately half the mice that develop primary lung tumors in 8-10 weeks also develop metastasis to the mediastinal lymph nodes in weeks 12-16. We used this model to test the hypothesis that vimentin loss prevents lung cancer metastasis by crossing this GEMM with a Vim-/- mouse to create a novel LSL-KrasG12D, LKB1fl/fl, Vim-/- (termed here KLV-/-) mouse. Our findings show that in the KLV-/- mouse, primary tumor burden and cell proliferation were not significantly different than wild-type KLV+/+ mice; however, KLV-/- mice exhibit significantly less metastasis to the mediastinal lymph nodes compared to their wild type counterpart indicating that vimentin contributes to the metastatic cascade. Consistent with this finding, histological analysis of the primary tumors show that KLV-/- mice exhibit less focal invasion than KLV+/+ and +/- mice, further confirming that KLV-/- mice have reduced invasiveness. Interestingly, vimentin staining in invasive regions of KLV+/+ mice was not found in the cancer cells but rather in fibroblast-like cells surrounding invasive cell buds that we term collective invasion packs (CIPs). These fibroblast-like, vimentin-positive cells also stain positive for alpha smooth muscle actin, which is consistent with cancer-associated fibroblasts (CAFs). Taken together, these results suggest that in this highly metastatic genetic background, vimentin may play a central role in recruiting CAFs to invading cancer cells but not necessarily in cancer cell epithelial to mesenchymal transition (EMT).

Citation Format: Alessandra M. Salgueiro, Melissa Gilbert-Ross, Lauren S. Havel, John Shupe, Allyson E. Koyen, Hans E. Grossniklaus, Gabriel Sica, Adam I. Marcus. Beyond EMT: Vimentin function in lung cancer metastasis. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C24.
Abstract C32: The function of GPR56 in metastasis formation of melanoma
Authors: Corson Nancy , Yang Liquan , Xu Lei
Published: October 2016

Disseminated cancer cells often persist in tissues for a long period before being manifested as clinically detectable metastases. This metastasis dormancy imposes a main threat for cancer patients, especially after their first line of cancer treatment. Little is known as to how this dormancy is maintained and what triggers its awakening, but tumor microenvironment is thought to play a decisive role. We discovered that a member of newly described family of adhesion G protein-coupled receptors (GPCRs), GPR56, inhibits metastasis formation of melanoma cell lines and sequesters them at a dormant state in lung. GPR56 binds to TG2, a component in extracellular matrix (ECM) that could also function as a cross linking enzyme. It is significantly up-regulated in human melanoma metastases relative to the primary tumors and its expression promotes metastasis formation of melanoma cells in the experimental metastasis model. The down-regulation of TG2 by GPR56 may abolish the pro-metastasis function of TG2 in melanoma cells via destabilizing ECM and contribute to their sequestration at the dormant state. Furthermore, RNAseq analyses suggest that GPR56 may regulate the expression of factors involved in cellular homeostasis. It is thus possible that GPR56 maintains metastasis dormancy in melanoma by down-regulating TG2 in ECM and perturbing cellular homeostasis.

Citation Format: Nancy Corson, Liquan Yang, Lei Xu. The function of GPR56 in metastasis formation of melanoma. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C32.
Abstract C39: High-content screening to capture tumor dynamics in response to microenvironmental perturbations
Authors: Garvey Colleen M. , Chen Oscar , Foo Jasmine , Mumenthaler Shannon M.
Published: October 2016

Tumor populations are in constant flux as a result of dynamic pressures of their surrounding microenvironment. Measuring the phenotypic response of multiple cell types exposed to physiological relevant tumor conditions has been a challenge due to the heterogenous nature of the tumor microenvironment. Further, traditional cell biology assays for assessing cell viability do not allow for additional downstream analyses and use surrogate measures for cell number, which may fail to provide a complete picture of cellular events. Here, we present a method to utilize high-content screening to generate quantitative, robust data sets characterizing cellular phenotypic responses (i.e. birth, death, morphology) of tumor cells to co-occurring perturbations of drug, oxygen, glucose, ECM stiffness, and stromal cell co-culture. Using an Operetta high-content imaging platform, we are able to perform multiple analyses on the same experimental setup to quantitatively assess the evolutionary dynamics of heterogenous cell populations under multiple environmental perturbations. We are able to differentiate between the effect of microenvironmental conditions on a decrease in cell birth versus increase in cell death, which has significant implications for predicting tumor growth kinetics and drug treatment response. We applied this platform to analyze isogenic lung tumor cells that are either sensitive or resistant to erlotinib, a commonly used tyrosine receptor kinase inhibitor in the treatment of lung cancer. We identified specific microenvironmental contexts where the resistant populations have a fitness advantage over the sensitive population, irrespective of the resistance mechanism. Furthermore, our experimental workflow allows us to capture and quantify cell morphology, an additional measure for overall cell health. We observed significant shifts in specific cell morphological parameters in response to alterations in tumor microenviromental conditions such as low oxygen and increased drug concentration. This novel application of a high-content screening platform allows for the quantification of multiple cellular phenotypes in response to over a hundred different microenvironmental contexts, thus providing deeper insight into the effect of tumor microenvironmental heterogeneity on evolving tumor cell populations.

Citation Format: Colleen M. Garvey, Oscar Chen, Jasmine Foo, Shannon M. Mumenthaler. High-content screening to capture tumor dynamics in response to microenvironmental perturbations. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C39.
Abstract C40: Pancreatic cancer and stroma cell cross-talk affects cell proliferation in a 3D spheroid co-culture model
Authors: Norberg Jessica K. , Nania Salvatore , Heuchel Rainer L. , Löhr Matthias J.
Published: October 2016

Aim of the study: The aim of this study was to validate a novel 3D spheroid co-culture model of pancreatic ductal adenocarcinoma (PDAC) cells and pancreatic stellate cells (PSCs), and to use said model as to investigate the effects of PDAC cell and PSC cross-talk on cell proliferation, cell death, migration and chemo-resistance.

Methods: An eGFP-positive PSC line and PDAC cell lines were cultured in 3D spheroid mono- and co-cultures. Activation of the PSCs within the co-culture model was investigated by real time PCR for whole spheroids and spheroid populations sorted by fluorescence activated cell sorting (FACS). To investigate cell proliferation the cell numbers within the cultures were followed over time and the proportions of the different cell types within the co-cultures were monitored by FACS.

Results: The mRNA expression of the PSC activation marker ASMA as well as the ECM proteins collagen I, laminin and lumican, the PDGFbeta receptor (PDGFRb) and the transforming growth factor beta1 (TGFb-1) downstream effector connective tissue growth factor (CTGF), were increased in PSCs within co-cultures compared to mono-cultures. PSCs were initially expanding but then diminished within 3D spheroid co-cultures together with two separate PDAC cell lines (Panc-1 and HPAF-II). Panc-1 cell numbers were seemingly unaffected by the presence of PSCs, but with higher proportions of PSCs the Panc1 cell numbers within the co-cultures initially were lagging behind but then caught up to the numbers within the mono-cultures. This growth switch was correlated with the opposite switch seen for the PSCs. The proliferation of HPAF-II cells, was on the other hand induced within the co-cultures compared to mono-cultures.

Conclusions: PSCs are activated within the 3D spheroid co-cultures. Both tumor cell and PSC proliferation is influenced by co-culturing the cells in the 3D spheroid model. Different PDAC cell – PSC combinations are affected differently. We currently are investigating the effects on cell death and apoptosis, migration and chemo-resistance.

Citation Format: Jessica K. Norberg, Salvatore Nania, Rainer L. Heuchel, Matthias J. Löhr. Pancreatic cancer and stroma cell cross-talk affects cell proliferation in a 3D spheroid co-culture model. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C40.
Abstract C42: DNA methyltransferase 1 (Dnmt1) is a key regulator of TGFβ-mediated endothelial-to-mesenchymal transition
Authors: Xiao Lin , Dudley Andrew C.
Published: October 2016

Cancer-associated fibroblasts (CAFs) are prominent in the tumor microenvironment and they fuel tumor angiogenesis, tumor growth, and metastasis. CAFs are identified by smooth muscle actin and type collagen 1 expression, they promote intratumoral desmoplasia and fibrosis, and they are derived from multiple cellular precursors including tumor endothelial cells (TECs) through a TGFβ-regulated process termed endothelial-to-mesenchymal transition (EndMT). Recently, we uncovered two distinct TEC populations: TGFβ-responders that undergo rapid EndMT accompanied by CAF marker up-regulation in response to TGFβ and TGFβ non-responders that are comparatively resistant to TGFβ-induced EndMT. From a biochemical screen, we found that 5-Azacytidine, a small-molecule inhibitor of DNA methyltransferases (DNMTs), converts TGFβ non-responders into responders suggesting that TGFβ responsiveness is dictated by epigenetic mechanisms. siRNA silencing of Dnmt1 is sufficient to promote TGFb-induced EndMT in non-responders, whereas Dnmt3a or Dnmt3b are not involved. Chronic (> 7 days) TGFβ stimulation also suppresses Dnmt1 expression and drives the conversion of non-responders into responders indicating that TGFβ may un-silence CAF-specific genes in TECs in part by antagonizing DNMT1 expression/activity. Our findings shed light on the epigenetic mechanisms that regulate TGFβ- and EndMT-mediated conversion of TECs into CAFs. Targeting these mechanisms could inhibit tumor growth and spread.

Citation Format: Lin Xiao, Andrew C. Dudley. DNA methyltransferase 1 (Dnmt1) is a key regulator of TGFβ-mediated endothelial-to-mesenchymal transition. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C42.
Abstract IA02: Immune checkpoint blockade in cancer therapy: New insights and opportunities, and prospects for cures
Authors: Allison James P.
Published: October 2016

The existence of multiple non-redundant inhibitory pathways that limit T cell responses offers novel strategies for mobilizing the immune system to attack cancer cells. The best characterized of these immune checkpoints is CTLA-4, which inhibits T cell proliferation by interfering with the interaction of the costimulatory molecule CD28 with its ligands B7-1 and B7-2 on the surface of antigen presenting cells. Antibodies to CTLA-4 have proven effective against multiple tumor types in both pre-clinical and clinical studies. Ipilimumab, an antibody to human CTLA-4, showed long term (>4 years) survival benefit in about 20% of patients in a randomized, placebo-controlled trial in late stage melanoma. A follow up study of almost 5,000 patients showed that 22% were alive 10 years after treatment disease.

The mechanism(s) of action of anti-CTLA-4 are still being elucidated. We and others have shown that CLTA-4 limits T cell proliferation by a cell intrinsic mechanism. However, there is also evidence that anti-CTLA-4 has to engage the target on both effector (Teff) and regulatory (Treg) T cells. Thus anti-CTLA-4 exerts its anti-tumor effects by multiple mechanisms.

PD-1, another checkpoint, recruits a phosphatase and seems to interfere with T cell antigen receptor mediated signaling. It has two ligands, PD-L1 and PD-L2, which are both expressed on dendritic cells. However, many tumor cells also express PD-L1. Antibodies to PD-1 and PD-L1 have both shown objective responses against several tumor types in clinical trials with response rates of about 25% . A recent phase III trial of a combination of anti-PD-1 and anti-CTLA-4 in melanoma showed objective responses in about 50% of late stage melanoma patients.

To date the US Food and Drug administration has issued 8 approvals for antibodies targeting CTLA-4 or PD-1 in a variety of indications, including melanoma, lung, and kidney cancer.

Emerging data suggest that T cell responses are largely directed toward neoantigens arising as a result of mutational events associated with the carcinogenesis. While all tumors with antigens recognizable by the immune system should be targets for checkpoint blockade, it is becoming clear that certain types of tumors with lower burdens of mutations (eg. prostate, breast, and kidney cancer) present special challenges for immune therapy. Strategies for effective treatment of such tumors will be discussed.

Citation Format: James P. Allison. Immune checkpoint blockade in cancer therapy: New insights and opportunities, and prospects for cures. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA02.
Abstract IA10: Convergent control of cancer associated fibroblast activation and field cancerization by Notch/CSL and p53 signaling
Authors: Dotto G. Paolo , Dotto G. Paolo
Published: October 2016

The vast majority of epithelial cancers is limited to in situ lesions that, for internal organs like breast, prostate or lung, can remain undetected for the whole life of an individual. The reason(s) why only a minor fraction of these lesions progresses into malignancy is not understood. Changes in tumor stroma are most frequently viewed as secondary to changes in the epithelium. However, recent evidence indicates that they may play a primary role. Such a possibility would help explain not only dormancy of most epithelial cancers, but also field cancerization, a condition of major clinical significance linked with multifocal and recurrent tumors and broader tissue changes beyond areas of tumor development that expand over time.

Stromal fibroblast senescence has been linked to aging-associated cancer risk. However, density and proliferation of cancer associated fibroblasts (CAF) are frequently increased. In the mouse, deletion of the Notch effector CSL/RBP-Jκ in dermal fibroblasts is sufficient for CAF activation and ensuing multifocal keratinocyte tumors. We report that CSL silencing induces senescence of primary fibroblasts of both mouse and human origin, and from dermis, oral mucosa, breast and lung. CSL functions in these cells as direct repressor of multiple senescence- and CAF-effector genes. It also physically interacts with p53, repressing its activity. CSL is down-modulated in stromal fibroblasts of premalignant skin actinic keratosis lesions and squamous cell carcinomas (SCC), while p53 expression and function is down-modulated only in the latter, with paracrine FGF signaling as likely culprit. Concomitant loss of CSL and p53 overcomes fibroblast senescence, enhances expression of CAF effectors and promotes stromal and cancer cell expansion. The findings support a CAF activation/stromal co-evolution model under convergent CSL/p53 control.

Citation Format: G. Paolo Dotto, G. Paolo Dotto. Convergent control of cancer associated fibroblast activation and field cancerization by Notch/CSL and p53 signaling. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA10.
Abstract IA13: The interplay between tumor cells, cancer associated fibroblasts, and immature myeloid cells in the esophageal tumor microenvironment
Authors: Karakasheva Tatiana , Lin Eric , Hicks Phil , Waldron Todd , Rustgi Anil K.
Published: October 2016

Esophageal cancer has two major subtypes: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). ESCC is more common worldwide and illustrative of other SCCs (e.g. head/neck, lung) from a molecular pathogenesis viewpoint. EAC is rising in incidence in the United States and Western Europe. Unfortunately, 5-year survival remains dismal for both types, at about 15%. Interrogation of the esophageal tumor microenvironment, replete with desmoplasia, CAFs and diverse immune cells, may afford opportunities to reveal new therapeutic targets, especially in a combinatorial fashion.

We have generated previously a conditional knockout model of p120-catenin whereby mice develop preneoplastic and neoplastic lesions in the esophagus. Tumor-derived cells secrete granulocyte macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-α (TNFα). The tumors contain significant desmoplasia and immune cell infiltration. Immature myeloid cells (myeloid deriver suppressor cells or MDSCs) comprise a significant percentage of the immune cells present and likely participate in fostering a favorable tumor microenvironment, including the activation of fibroblasts. We have identified CD38 as playing a vital role in MDSC biology. CD38 belongs to the ADP-ribosyl cyclase family and possesses both ectoenzyme and receptor functions. It has been described to function in lymphoid and early myeloid cell differentiation, cell activation, and neutrophil chemotaxis. CD38high MDSCs are more immature than MDSCs lacking CD38 expression, suggesting a potential role for CD38 in the maturation halt found in MDSC populations. CD38high MDSCs also possess a greater capacity to suppress activated T cells, and promote tumor growth to a greater degree than CD38low MDSCs, likely as a result of increased iNOS production. In addition, we have identified novel tumor–derived factors, specifically IL-6, IGFBP3, and CXCL16, which induce CD38 expression by MDSCs ex vivo. Finally, we have detected an expansion of CD38+ MDSCs in peripheral blood of advanced-stage cancer patients. Additional work reveals cross-talk between CAFs and tumor cells through the induction of IL-6 and RANTES, suggesting there is interaction between tumor cells, CAFs and MDSCs. In aggregate, we find that CD38 (on MDSCs), IL-6 and RANTES (secreted by tumor cells and CAFs) serve to provide novel approaches in therapy.

Citation Format: Tatiana Karakasheva, Eric Lin, Phil Hicks, Todd Waldron, Anil K. Rustgi. The interplay between tumor cells, cancer associated fibroblasts, and immature myeloid cells in the esophageal tumor microenvironment. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA13.
Abstract IA14: Breaking bad: Cancer-associated fibroblasts are reprogrammed from growth inhibitory to pro-inflammatory and tumor promoting in breast cancer
Authors: Sharon Yoray , Ershaid Nour , Raz Yael , Cohen Noam , Pasmanik-Chor Metsada , Geiger Tamar , Erez Neta
Published: October 2016

Breast tumors are characterized by an extensive desmoplastic stroma, abundantly populated by fibroblasts. We previously demonstrated that Cancer-Associated Fibroblasts (CAFs) orchestrate tumor-enhancing inflammation in multiple mouse and human malignancies, including breast cancer. Although breast cancer is one of the major tumor types where CAFs were shown to be tumor promoting, there is no detailed analysis of the dynamic changes in CAFs characteristics and function in correlation with tumor progression. We therefore set out to characterize the dynamic changes in CAFs during progression of mammary carcinogenesis, in a transgenic mouse model of human breast cancer. We profiled the transcriptome of fibroblasts isolated from normal mammary glands, or from mammary glands of transgenic mice at defined tumorigenic stages. Data analysis revealed unique CAF gene signatures that correspond to distinct tumor stages, with only partial overlap between the stages, suggesting co-evolution of the microenvironment with tumorigenic progression. Interestingly, the gene signature of fibroblasts isolated from hyperplastic lesions is inverse to that in CAFs from neoplastic stages, and has a growth inhibitory phenotype, while CAFs from mammary tumors express pro-inflammatory and tumor promoting gene signatures. Moreover, we functionally demonstrate that CAFs isolated from late carcinoma express a gene signature that links tissue damage with tumor-promoting inflammation. To identify tumor-secreted factors capable of reprogramming normal mammary fibroblasts to pro-inflammatory CAFs, we performed a proteomic screen of breast cancer cells secretome, and identified Osteopontin (OPN). Knockdown of OPN in tumor cells in vivo resulted in attenuated stromal activation, reduced immune cell recruitment and inhibition of tumor growth. Taken together, our findings reveal reciprocal crosstalk between fibroblasts and cancer cells which drives CAF reprogramming, to facilitate tumor progression in breast cancer.

Citation Format: Yoray Sharon, Nour Ershaid, Yael Raz, Noam Cohen, Metsada Pasmanik-Chor, Tamar Geiger, Neta Erez. Breaking bad: Cancer-associated fibroblasts are reprogrammed from growth inhibitory to pro-inflammatory and tumor promoting in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA14.
Abstract IA18: Latency and immune evasion of metastatic stem cells
Authors: Massagué Joan
Published: October 2016

Metastasis frequently develops years after the removal of a primary tumor, from a minority of disseminated cancer cells that survived as latent entities. An improved understanding of the location and survival mechanisms of disseminated cancer cells, and their ability to enter a quiescent state, evade immune surveillance, and retain tumor reinitiating capacity is needed to better prevent and treat metastatic cancer. To this end, we isolated latency competent cancer (LCC) cells from early-stage human lung and breast carcinoma cell lines and defined the mechanisms that prevent the outgrowth, support the long-term survival, and maintain the tumor-initiating potential of these cells during latent metastasis. LCC cells show stem cell-like characteristics and express Sox transcription factors, which are essential for their survival in host organs under restrictive conditions and for metastatic outgrowth under permissive conditions. Through autocrine suppression of WNT signaling and heightened TGF-β signaling, LCC cells self-impose a slow-cycling state with broad down-regulation of NK cell activators. By actively entering quiescence, these metastatic stem cells can evade innate immunity to remain latent for extended periods.

Citation Format: Joan Massagué. Latency and immune evasion of metastatic stem cells. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA18.
Abstract IA24: Forcing through tumor metastasis: Regulation of epithelial-mesenchymal plasticity by matrix stiffness
Authors: Yang Jing
Published: October 2016

In cancer, the presence of dense clusters of collagen fibrils indicates increased matrix stiffness and correlates with poor survival. Previous studies have identified a functional role for matrix stiffness in driving tumor progression, but it is unclear how mechanical inputs are transduced into transcriptional outputs to drive tumor metastasis.

To investigate mechanisms of tumor cell mechanotransduction, we utilized a 3D Matrigel culture of murine (Eph4Ras) or human (MCF10A, MCF10DCIS, Bt-549) mammary epithelial cells coupled with a polyacrylamide hydrogel base with calibrated elastic moduli ranging between ~150Pa of normal mammary gland and ~5700Pa of breast tumor tissues. This approach allows for the interrogation of the effects of changes in matrix stiffness independent of other biochemical variables in extracellular matrix (ECM). Using this system, we show that increasing matrix stiffness induced morphological changes resembling the Epithelial-Mesenchymal Transition (EMT) program. Therefore, we hypothesized that increasing matrix stiffness could directly signal through EMT-inducing transcription factors to induce EMT and promote invasion.

Using a combination of bioengineering, cell biollogy, proteomic, imaging, and murine tumor modeling approaches, we found that the EMT-inducing transcription factor TWIST1 is an essential mechanomediator that promotes EMT in response to increasing matrix stiffness. Loss of Twist1 prevents matrix stiffness-induced EMT and tumor cell invasion. TGF-beta signaling, a major EMT-inducing biochemical signal, acts synergistically with increasing matrix stiffness, the mechanical cure to induce a complete EMT program in a Twist1-dependent manner. At the compliant matrix stiffness, TWIST1 is sequestered in the cytoplasm by its cytoplasmic binding partner G3BP2, thus preventing TWIST1 from accessing DNA to drive EMT. High matrix stiffness promotes nuclear translocation of TWIST1 by releasing TWIST1 from G3BP2. Loss of G3BP2 leads to constitutive TWIST1 nuclear localization and synergizes with increasing matrix stiffness to induce EMT and invasion in a Twist1-dependent manner. In MCF10DCIS breast tumor xenografts, loss of G3BP2 promotes local invasion and distant metastasis in the lung. In human stage-3 breast tumors, collagen fiber alignment, a marker of increasing matrix stiffness, and reduced expression of G3BP2 together predict poor survival.

Together, our findings reveal a TWIST1-G3BP2 mechanotransduction pathway that responds to biomechanical signals from the tumor microenvironment to drive EMT, invasion and metastasis.

Citation Format: Jing Yang. Forcing through tumor metastasis: Regulation of epithelial-mesenchymal plasticity by matrix stiffness. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr IA24.
Abstract PR05: Control of the melanoma metastatic phenotype by A-to-I microRNA editing
Authors: Shoshan Einav , Huang Li , Vasquez Mayra E. , Lee Ho-Jeong , Kim Sun-Jin , Ivan Cristina , Calin George A. , Sood Anil K. , Hwu Patrick , Gershenwald Jeffrey E. , Markel Gal , Fidler Isaiah J. , Bar-Eli Menashe
Published: October 2016

Although recent studies have shown that adenosine-to-inosine (A-to-I) RNA editing occurs in microRNAs, its effects on tumor growth and metastasis are not well understood. We present evidence of CREB-mediated low expression of ADAR1 in metastatic melanoma cell lines and tumor specimens. Re-expression of ADAR1 resulted in the suppression of melanoma growth and metastasis in vivo. Consequently, we identified 3 miRs (miR-455-5P, mir-378-3P, miR-324-5P) undergoing A-to-I editing in the low-metastatic melanoma cell lines but not in highly metastatic. One of these miRs, miR-455-5P has two A-to-I RNA editing sites. The biological function of edited miR-455-5P is different from the unedited form. Indeed, w.t. miR-455 promotes melanoma metastasis via inhibition of the tumor suppressor gene CPEB1 . Moreover, w.t. miR-455 enhances melanoma growth and metastasis in vivo while the edited form inhibits these features mainly by affecting the tumor microenvironment. TCGA analysis confirmed accumulation of wild-type miR-455 in metastatic melanoma lesions. These results demonstrate a previously unrecognized role of RNA editing in melanoma progression.

Citation Format: Einav Shoshan, Li Huang, Mayra E. Vasquez, Ho-Jeong Lee, Sun-Jin Kim, Cristina Ivan, George A. Calin, Anil K. Sood, Patrick Hwu, Jeffrey E. Gershenwald, Gal Markel, Isaiah J. Fidler, Menashe Bar-Eli. Control of the melanoma metastatic phenotype by A-to-I microRNA editing. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr PR05.
Abstract PR07: Mechanisms of stromal reprogramming mediated by heat shock factor 1
Authors: Scherz-Shouval Ruth , Mendillo Marc L. , Gaglia Giorgio , Ben-Aharon Irit , Beck Andrew H. , Whitesell Luke , Lindquist Susan
Published: October 2016

For tumors to form, progress and metastasize, they must recruit and reprogram normal cells in their microenvironment into a pro-tumorigenic stroma. Yet little is known about the pathways leading to stromal reprogramming. We hypothesized that such reprogramming would not be mediated by classic oncogenes, since the stroma is relatively genetically stable. Instead we propose that cancer cells hijack normal cytoprotective stress responses, and subvert them to enable stromal reprogramming. We found that Heat-shock factor 1 (HSF1), master regulator of the heat-shock response, plays a crucial role in this process. Across a broad range of human cancers, HSF1 is activated in cancer-associated fibroblasts (CAFs). In early stage breast and lung cancer, high stromal HSF1 activation is strongly associated with poor patient outcome. In fibroblasts co-cultured with cancer cells, HSF1 drives a transcriptional program that supports cancer phenotypes. This program is profoundly different from the transcriptional program it drives in cancer cells or in heat-shocked cells. Here we characterize mechanisms leading to activation of this unique stromal program and describe the contribution of cancer cells to this process. We then explore the stromal HSF1 program in patients. We apply computational and experimental approaches to define independent cancer and stromal HSF1 signatures and highlight the prognostic value of these signatures in human breast cancer. Billions of years of evolution through changing environments led organisms to develop an arsenal of cytoprotective pathways to promote their survival under stressful conditions. Our work provides insights into the ways by which tumors co-opt these normal biological networks to support their survival in the stressful tumor microenvironment.

This abstract is also presented as Poster B40.

Citation Format: Ruth Scherz-Shouval, Marc L. Mendillo, Giorgio Gaglia, Irit Ben-Aharon, Andrew H. Beck, Luke Whitesell, Susan Lindquist. Mechanisms of stromal reprogramming mediated by heat shock factor 1. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr PR07.
O jornalismo no Brasil e as mediações da produção de O segredo da pirâmide
Authors: Pontes Felipe Simão
Published: October 2016

The objective is to contextualize the book O segredo da pirâmide: para uma teoria marxista do jornalismo [The secret of the pyramid: for a Marxist theory of journalism], by the Brazilian theoretician Adelmo Genro Filho, facing the questions of Brazilian journalism in the 1980s. As an analysis device, we performed a detailed reading of four texts edited in August 5, 1984, in the section “Folhetim”, of the newspaper Folha de S. Paulo, and of the first seven paragraphs of the book. Among the main themes presented are the need for specific training for the profession, the role and shortcomings of communication schools for the training of journalists, the division of value and power within newsrooms, and thwe lack of dialogue theories with practice of journalists.
Uma questão de método: notas sobre a análise de som e música no cinema
Authors: Carreiro Rodrigo , Alvim Luíza
Published: October 2016

To establish accurate methods that enable the rigorous study of the soundtrack in audiovisual products has been a recurring problem in film studies in Brazil. This essay critically examines manuals, books and articles from different areas of study, including Social Communication, Film Analysis and Sound Studies, in order to compile suggestions of methods of sound and music analysis in audiovisuals that may help future researchers.
Análise de redes sociais on-line: um guia para iniciação teórica e prática
Authors: Sousa Ana Lúcia Nunes de
Published: October 2016

In this book, the authors Raquel Recuero, Marco Bastos and Gabriela Zago present the reader with a simple and accessible guide for initiation into the analysis of social networks as a research methodology of social media, as for instance, Facebook and Twitter. The basic concepts, a brief history of the study of social networks, patterns and analysis software and a rich set of examples, where the social media analysis can be applied, are presented in the work. The intention of the authors is to popularize the methodology and the tools so that more researchers can explore the field of social media.
Omissão histórica e repressão psíquica em Boogie Nights de Paul Thomas Anderson
Authors: Modleski Tania
Published: October 2016

Exquisitely filmed in Altmanesque style and drawing on scenes from the films of Martin Scorsese and Quentin Tarantino, Boogie Nights continues to this day to be proclaimed an ultra hip and daring look at the so-called Golden Age of pornography set of the 1970s. In this essay I attempt to document what this film leaves out of the historical record, and to show how historical suppression dovetails with psychic repression. Instead of history we are presented with melodrama. Instead of a historical document, Boogie Nights gives us, again, Oedipus. Like most elegies, the negative or undesirable aspects of the subject are minimized or omitted, although they come back to haunt the text.
Side effects of itraconazole on post-metamorphic Alytes obstetricans after a cold stress
Authors: Loyau Adeline , Cornuau Jérémie H. , Clare Frances C. , Schmeller Dirk S.
Published: October 2016

Itraconazole is the most widely used treatment against Batrachochytrium dendrobatidis (Bd), the fungal pathogen causing chytridiomycosis, a proximate cause of amphibian declines. Several side effects of itraconazole treatment, ranging in severity from depigmentation to death have been reported in different amphibian species and life stages, and these side effects were observed at commonly used dosages of itraconazole. However, no studies have investigated side-effects of itraconazole in conjunction with environmental stress. Post-metamorphic midwife toads (Alytes obstetricans) that were treated with itraconazole and subsequently exposed to a cold stress (exposure to 4°C cold water) had higher mortality rates compared to untreated individuals. Moreover, adults of booroolong frogs (Litoria booroolongensis) treated with itraconazole had a higher probability to become infected when subsequently exposed to Bd. Our results suggest that a post-metamorphosis itraconazole treatment of infected midwife toads combined with a subsequent release into the wild may be an ineffective disease mitigation strategy, as the cold stress during hibernation and/or exposure to Bd in the wild may reduce the hibernation emergence rate of treated individuals in this species.
The Nation in the Balkan Village: National Politicization in Mid-Nineteenth-Century Ottoman Thrace
Authors: Lyberatos Andreas Kosmas
Published: October 2016

The paper tackles the issue of national politicization in late Ottoman Thrace through the case study of Stenimahos (İstanimaka, Stanimaka), a large mountainous village in Northern Thrace, whose Greek-speaking inhabitants initiated during the 1860s a long tradition of anti-Ottoman nationalist militancy and a close relation to independent Greece. The rapid national politicization and radicalization of the Stenimahiote Greeks was triggered by a severe reproduction crisis of the local economy in the context of mounting incorporation of the Ottoman empire into the world economy. Ensuing conflicts in local society were successively articulated into the unstable ‘post-Crimean war’ regional, imperial and international contexts. Last but not least, the analysis of the ‘amphibious’ emigration movement of the Stenimahiotes to Greece which followed the crisis reveals the agency of the non-elite subjects and challenges idealist and ‘top-bottom’ approaches to the process to nation formation in the late Ottoman Balkans.
Bottom Temperatures in Drake Passage
Authors: Tracey Karen L. , Donohue Kathleen A. , Watts D. Randolph
Published: October 2016

Long time series of bottom temperatures in the Southern Ocean are rare. The cDrake array with over 40 current- and pressure-recording inverted echo sounders, moored across Drake Passage to monitor the Antarctic Circumpolar Current (ACC) variability and transport, measured temperature at 1 and 50 m above the seafloor at depths ≥ 3500 m and at the southern continental margin. The 4-yr dataset provided an opportunity to examine the temporal and spatial scales of bottom temperature variability. High variability was observed; ranges were 0.5°–0.9°C in the northern passage and 0.3°–0.6°C in the southern passage. Standard deviations in the two regions were 0.1°–0.15°C and <0.05°C, respectively. Meandering of the ACC with its deep-reaching thermocline accounted for up to 50% of the observed bottom temperature variance. Northern passage temperatures, spaced less than 40 km apart, were correlated with each other, while those in the southern portion, separated by 60–70 km, were not. A gap in the West Scotia Ridge provided a deep passageway for cold water to reach the northern passage from the southern basin; an extreme event during February 2008 brought bottom waters with in situ temperatures below 0.38°C as far north as 57°S. Strong vertical temperature gradients between 1 and 50 m above the bottom occurred intermittently due to intrusions associated with deep eddy circulations arising beneath the meandering jet and to flow over steep topography, permitting the generation of internal waves. High variability in temperature on interannual time scales requires record lengths of 13–17 yr to estimate long-term trends reliably.
Fun and Sexy, but Less Responsible
Authors: Flores Ximena , Gibbons Judith L. , Poelker Katelyn E.
Published: October 2016

Globalisation is transforming the lives, ideals and development of youth worldwide, including adolescents in Guatemala. We hypothesised that the attitudes of today’s Guatemalan adolescents as reflected in their views of the ideal man and woman would more closely converge with those of the global adolescent compared to their compatriots 25 years earlier. Urban adolescents’ ratings and drawings in 2014 (N = 397, Mage = 12.55, 63.13 per cent girls) were compared to those from 25 years earlier (1988–1990; N = 488, Mage = 12.82, 46.35 per cent girls). Core characteristics such as kindness and honesty were important in both time periods. Other qualities (the importance of being fun and the depiction of sexiness in the drawings) were more prominent among present-day adolescents. However, adolescents in 2014 were less likely to draw the ideal person with adult responsibilities. Adolescent values and beliefs are nuanced and depend both on globalisation and the specific cultural context.
The sustainable and green engine (SAGE) – Aircraft engine of the future?
Authors: Smith David J.
Published: October 2016

The case of the European Union’s (EU) Clean Sky initiative and its sustainable and green engine programme focuses on a sector where the implications of climate change are likely to be keenly felt in the coming decades, namely air transport. It is a sector where to date there have been few green or eco innovations. The case focuses on a current EU-funded initiative designed to limit the impact of air transport on climate change. The initiative aims to foster innovation through the introduction of open rotor technology to power the next generation of short-/medium-haul airliners. This technology could potentially cut carbon dioxide emissions from commercial aircraft by 100 million tonnes per year. However, it may also prove to be a disruptive technology rendering existing aircraft and possibly some of the firms that produce them, obsolete. As well as introducing some of the features of disruptive technologies, the case highlights both the drivers for and barriers to the successful adoption of green innovations. Another important aspect of the case is that it also highlights the value of appropriate business strategies, such as the use of technology demonstrator programmes, in supporting and facilitating the adoption and diffusion of green innovations.