bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A140: MERTK mediates intrinsic and adaptive resistance to AXL-targeting agents
Authors: McDaniel Nellie K. , Cummings Christopher T. , Brand Toni M. , Iida Mari , Hulse Justus , Pearson Hannah E. , Orbuch Rachel A. , Ondracek Olivia J. , Davies Kurtis D. , Gill Parkash , Wang Xiaodong , Frye Stephen V. , Earp H. Shelton , Kimple Randall J. , Harari Paul M. , DeRyckere Deborah , Graham Douglas K. , Wheeler Deric L.
Published: August 2018

The TAM family of receptor tyrosine kinases (RTKs) has been discovered to play a predominant role in promoting the growth, survival, and metastatic spread of several tumor types. AXL and MERTK are two TAM family RTKs that are overexpressed in head and neck squamous cell carcinoma (HNSCC), triple-negative breast cancer (TNBC), and non-small cell lung cancer (NSCLC), malignancies that are highly metastatic and lethal. The AXL receptor is the most well-characterized TAM receptor and has been found to mediate resistance to both conventional and targeted cancer therapies. Since AXL is overexpressed in aggressive tumor types, cancer patients are currently being enrolled in clinical trials testing AXL inhibitors. In the current study, we analyzed the efficacy of AXL inhibitors—both small molecule and monoclonal antibody therapy—in HNSCC, TNBC, and NSCLC preclinical models. We observed limited efficacy of anti-AXL targeting strategies across these different models, which was attributed to the upregulation of MERTK. MERTK was robustly overexpressed in cell lines and patient-derived xenografts treated with AXL inhibitors. Inhibition of MERTK sensitized HNSCC, TNBC, and NSCLC preclinical models to AXL inhibitors, leading to a more potent blockade of downstream signaling, decreased expansion of tumor cells in culture, and reduced tumor growth in vivo. Furthermore, ectopic overexpression of MERTK in AXL inhibitor-sensitive models resulted in resistance to AXL-targeting strategies. These results suggest that cotargeting both AXL and MERTK may be highly beneficial in a variety of tumor types where both receptors are expressed and may therefore prolong antitumor effects and improve the survival of patients with lethal malignancies.

Citation Format: Nellie K. McDaniel, Christopher T. Cummings, Toni M. Brand, Mari Iida, Justus Hulse, Hannah E. Pearson, Rachel A. Orbuch, Olivia J. Ondracek, Kurtis D. Davies, Parkash Gill, Xiaodong Wang, Stephen V. Frye, H. Shelton Earp, Randall J. Kimple, Paul M. Harari, Deborah DeRyckere, Douglas K. Graham, Deric L. Wheeler. MERTK mediates intrinsic and adaptive resistance to AXL-targeting agents [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A140.
Abstract A146: Stromal neuregulin-1 modulates the response to MEK inhibitors in WT BRAF/WT NRAS (WT/WT) melanomas
Authors: Capparelli Claudia , Purwin Timothy J. , Heilman Shea , Chervoneva Inna , Davies Michael A. , Gershenwald Jeffrey  E. , Aplin Andrew E.
Published: August 2018

MEK-ERK1/2 signaling is elevated in the majority of melanomas. While MEK inhibitors (MEKi) are FDA-approved for mutant BRAF melanoma, and have some activity against NRAS mutant tumors, they have shown little activity in patients with melanomas that are wild type for BRAF and NRAS (WT/WT). Since the tumor microenvironment (TME) often regulates drug resistance, we tested the effects of growth factors on WT/WT melanoma growth in the presence of MEKi. Neuregulin-1 (NRG1) protected patient-derived WT/WT human melanoma cell lines from growth inhibition mediated by trametinib (MEKi). Phospho-proteomic analysis and clinical grade neutralizing antibodies implicated adaptive activation of ErbB3/ErbB2 complexes in the protective effects of NRG1. NRG1 was detected in fibroblasts and cancer-associated fibroblasts (CAF), and CAF-conditioned medium activated ErbB3/ErbB2 signaling in MEK inhibited WT/WT melanoma cells. ErbB3 and ErbB2 neutralizing antibodies blocked the protective effects of fibroblast- and CAF-derived NRG1 in vitro and cooperated with MEKi to delay xenograft growth in vivo. Together our results provide a rationale for the treatment of WT/WT melanomas with the combination of MEKi and anti-ErbB3/ErbB2 antibodies.

Citation Format: Claudia Capparelli, Timothy J. Purwin, Shea Heilman, Inna Chervoneva, Michael A. Davies, Jeffrey  E. Gershenwald, Andrew E. Aplin. Stromal neuregulin-1 modulates the response to MEK inhibitors in WT BRAF/WT NRAS (WT/WT) melanomas [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A146.
Abstract A180: The histone methyltransferase SETDB1 contributes to melanoma tumorigenesis
Authors: Orouji Elias , Federico Aniello , Larribere Lionel , Novak Daniel , Utikal Jochen
Published: August 2018

Histone modifications play a significant role in the development and progression of various cancers. The histone methyltransferase SETDB1 (SET domain, bifurcated 1) catalyzes the addition of methyl groups to histone H3 at lysine 9 (H3K9). In the present study, we demonstrate that SETDB1 contributes to melanoma tumorigenesis. We show SETDB1 to be highly amplified in melanoma tissues of patients with poor prognosis. The amplification of SETDB1 correlates with the increased expression of the protein.

Functional studies show an increased SETDB1 expression to be associated with a more proliferative, invasive and migratory phenotype and give rise to larger tumor masses in xenograft mouse models. In human primary melanomas, SETDB1 expression is elevated at the invasive borders. The activity of SETDB1 can be blocked by small molecules, which leads to reduced cell growth even in melanoma cell lines that are resistant towards BRAF and MEK inhibitors.

In conclusion, our findings support SETDB1 as a major driver of melanoma development and progression. We therefore suggest SETB1 as a potential future target for the treatment of melanoma.

Citation Format: Elias Orouji, Aniello Federico, Lionel Larribere, Daniel Novak, Jochen Utikal. The histone methyltransferase SETDB1 contributes to melanoma tumorigenesis [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A180.
Abstract 1009: Reciprocal roles of cancer associated fibroblasts and CD4+ T cells in ovarian cancer progression
Authors: Hu Ye , Orsulic Sandra
Published: August 2018

Recent evidence suggests that the efficacy of tumor immunotherapy is reliant on the signals received from the tumor microenvironment. The two prevalent cell types in the tumor microenvironment are immune cells and cancer-associated fibroblasts (CAFs). The presence of CAFs has been associated with poor survival in multiple cancer types and CAF-targeting in several experimental mouse cancer models has been shown to improve tumoral immune response and therapeutic efficacy.

By conducting immunohistochemistry in 42 patient-matched primary, metastatic, and recurrent ovarian tumors, We have shown that both CAF activation and CD4+ T cell infiltration increase during cancer progression. Upon co-culturing human CAFs with CD4+ T cells, We found that CAFs physically attract CD4+ T cells. In turn, CD4+ T cells activate CAFs, as indicated by the increased ability of CAFs to contract extracellular matrix. Further experiments showed more immune suppressive T cell subtypes (Th2 and Treg cells), when co-culture activated human CAFs with CD4+ Naive T cells.

A recent analysis of chemokines has shown that their expression is highly variable in primary ovarian tumors. Differential expression of chemokines in different areas of the tumor may result in a skewed distribution of immune cell types. We searched for genes that belong to the KEEG pathway ‘cytokine-cytokine receptor interaction' that are differentially expressed in the mesenchymal and mesenchymal subtype-equivalent C1 subtypes compared to all other subtypes in the TGCA and GEO datasets. Our comparison of the top 50 differentially expressed cytokine-cytokine receptor interaction genes in the mesenchymal and C1 subtypes revealed high gene signature conservation, with 32 of 50 genes being shared, including CXCL12, CXCL14, CCL11, CCL26 and KDR. Flow cytometry results showed over-expression of some cytokines in CAFs could foster CAFs into more active state, which created an immune suppressive environment by turning more T cells to Th2 and Treg subtypes.

In summary, ovarian CAFs may have great impact on immune cells proliferation and differentiation, thus influence tumor progression.

Citation Format: Ye Hu, Sandra Orsulic. Reciprocal roles of cancer associated fibroblasts and CD4+ T cells in ovarian cancer progression [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 1009.
Abstract 1014: Pharmacological modulation of PDAC stroma to enhance checkpoint blockade immunotherapy
Authors: Zhao Jun , Xiao Zhilan , Overwijk Willem , Li Chun
Published: August 2018

Sonic hedgehog signaling pathway is an important regulator during the initiation and progression of pancreatic cancer, and sustained activation of this pathway contributes to excessive deposition of tumor stroma and maintenance of tumor-initiating cells. Cyclopamine (CPA) is a potent inhibitor of the SHH pathway. In this work, we encapsulated both paclitaxel (PTX) and CPA in a long-circulating polymeric micelles to obtain M-CPA/PTX. In a genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC) (KPC model), systemic administration of M-CPA/PTX significantly prolonged the median survival of mice with well-established tumors from 23 days with nab-paclitaxel or gemcitabine to 58 days post-enrollment (p<0.0001). Further studies indicated that M-CPA/PTX modulated PDAC stroma by softening extracellular matrix, increasing blood perfusion, and alleviating hypoxia without depletion of α-smooth muscle actin-positive tumor-associated fibroblasts. Significantly, combination of M-CPA/PTX and anti-PD-1 immunotherapy significantly prolonged the survival of PDAC-bearing KPC mice compare with monotherapies (p<0.01). In an immune-competent, orthotopic PDAC model bearing established murine PDAC, treatments with combined M-CPA/PTX and anti-PD-1 enhanced tumor infiltration of CD8+ T cells and IFNγ expression. Neutralization of either CD8 T cells or INFγ nullified the therapeutic gain achieved with combination therapy. Thus, M-CPA/PTX enhanced checkpoint blockade immunotherapy through modulation of PDAC stroma and enhanced tumor infiltration of effector immune cells.

Citation Format: Jun Zhao, Zhilan Xiao, Willem Overwijk, Chun Li. Pharmacological modulation of PDAC stroma to enhance checkpoint blockade immunotherapy [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 1014.
Abstract 1021: Clinical significance of tertiary lymphoid structures (TLS) and tumor-infiltrating plasma cells in ovarian cancer
Authors: Ukita Masayo , Hamanishi Junzo , Baba Tsukasa , Murakami Ryusuke , Abiko Kaoru , Mandai Masaki
Published: August 2018

Objective: Tertiary lymphoid structures (TLS) are transient ectopic lymphoid aggregates that reflect lymphoid neogenesis mainly through CXCL13 and develop under chronic inflammation. Recently TLS have been detected in several types of cancers; however, there are few reports about TLS in ovarian cancer. We investigated the clinical significance of TLS in ovarian cancer.

Methods: 28 patients who were diagnosed with high-grade serous ovarian cancer and treated surgically in our hospital were selected from microarray dataset (KOV-75; GSE39204/55512). We evaluated TLS, tumor-infiltrating lymphocyte (TIL) subsets (CD4+ T cell, CD8+ T cell, CD20+ B cell, CD38+ plasma cell), and the correlation between expression of CXCL13 and TIL subsets by immunohistochemical staining. We analyzed the correlation between gene expression of CXCL13 and the survival time of the patients (pts) by using KOV-75 and the cancer genome atlas (TCGA) datasets.

Results: Immunohistochemical staining revealed that TLS were detected in 64% (18 pts) of ovarian cancer patients, and the numbers of tumor-infiltrating CD8+ T cells, CD20+ B cells and CD38+ plasma cells were significantly higher in cases with TLS (p<0.05). The numbers of tumor-infiltrating CD4+ T cells, CD8+ T cells, CD20+ B cells and CD38+ plasma cells were significantly higher in the CXCL13-high tumor than in the CXCL13-low tumor (p<0.001). In the group with high intratumoral infiltration of CD8 T cells and plasma cells, progression-free survival and overall survival were both significantly extended (p<0.05, respectively). In microarray analyses of KOV-75 and TCGA, high CXCL13 gene expression correlated significantly with both favorable progression-free survival and overall survival (p<0.05, respectively).

Conclusion: CXCL13 contributes to better prognosis in ovarian cancer patients by inducing TLS and various subsets of TIL. Induction of CXCL13 might be a new therapeutic target for ovarian cancer patients.

Citation Format: Masayo Ukita, Junzo Hamanishi, Tsukasa Baba, Ryusuke Murakami, Kaoru Abiko, Masaki Mandai. Clinical significance of tertiary lymphoid structures (TLS) and tumor-infiltrating plasma cells in ovarian cancer [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 1021.
Abstract 1027: Regulatory T-cell genes drive altered immune microenvironment in adult solid cancers and allow for immune contextual patient subtyping
Authors: Brouwer Jurriaan , Cheng Wei-Yi , Bauer-Mehren Anna , Maisel Daniela , Lechner Katharina , Andersson Emilia , Dudley Joel T. , Milletti Francesca
Published: August 2018

The tumor microenvironment is an important factor in cancer immunotherapy response. To further understand how a tumor affects the local immune system, we analyzed immune gene expression differences between matching normal and tumor tissues. We analyzed previously published and new gene expression data from solid cancers and isolated immune cell populations. We also determined the correlation between CD8, FoxP3 immunohistochemistry (IHC) and immune-related genes. Across solid TCGA cancers, we observed that regulatory T-cells (Tregs) were one of the main drivers of immune gene expression differences between normal and tumor tissues. A tumor-specific CD8 signature had slightly lower scores in tumor tissues compared to normal of most (12 of 16) cancers, while a Treg signature score was higher in tumor tissues of all cancers except liver. We clustered TCGA colorectal samples (626 patients) and a new separate testing data set (60 patients) into two groups according to Treg gene signature expression. The High Treg cluster had more colorectal tumors that were Consensus Molecular Subtype 1/4, right-sided and microsatellite-instable, compared to the Low Treg cluster. Finally, we determined the correlation between CD8, FoxP3 immunohistochemistry (IHC) and our gene signatures and found that in this small data set correlation between signature and IHC overall was low, but samples in the High Treg cluster had significantly more CD8+ and FoxP3+ cells compared to the Low Treg cluster. We conclude that high Treg signature expression scores correlate with high overall immune gene expression. Using this novel way of classifying patients, more colorectal tumors with high immune activation were identified compared to other colorectal subtyping methods. Further research will reveal if this Treg-based subtyping improves the identification of patients that may benefit from cancer immunotherapy.

Citation Format: Jurriaan Brouwer, Wei-Yi Cheng, Anna Bauer-Mehren, Daniela Maisel, Katharina Lechner, Emilia Andersson, Joel T. Dudley, Francesca Milletti. Regulatory T-cell genes drive altered immune microenvironment in adult solid cancers and allow for immune contextual patient subtyping [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 1027.
Abstract 1040: Patient derived xenografts of hematologic malignancies for translational research
Authors: Siegert Antje , Brzezicha Bernadette , Fuhrmann Stephan , Karawajew Leonid , Janz Martin , Schmitt Clemens , Fichtner Iduna , Hoffmann Jens
Published: August 2018

Acute leukemias and lymphomas represent a very heterogeneous group of hematologic malignancies and pose an important challenge in the clinical routine. They frequently develop resistance to the treatment with standard-of-care (SoC) drugs and have a high incidence of disease recurrence. Recent progress in molecular profiling has helped to identify new potential drivers for the different leukemia and lymphoma subtypes, with some of them being potential therapeutic targets. Further target validation and drug development projects are highly dependent on corresponding preclinical models representing the different clinical subtypes. Therefore, we started to establish and characterize new patient derived xenografts (PDX) of AML, ALL and lymphomas for drug development and translational research.

AML- and ALL-PDX were derived from bone marrow aspirates or peripheral blood samples, from primary or relapsed acute leukemia patients. Purified cells were transplanted either intravenously (i.v.) and/or subcutaneously (s.c.) into immunodeficient mice. Some mice developed a systemic AML, which was monitored by flow cytometric analysis of blood samples. Non-Hodgkin- or Hodgkin lymphoma-PDX were derived from peripheral blood, lymph node extirpations or core needle biopsies, and were usually transplanted subcutaneously into immunodeficient mice.

For further characterization, established PDX models were treated with SoC and investigational drugs. In parallel, gene expression profiles as well as mutations were analyzed within the first in vivo passages.

More than 20 new PDX models from AML, ALL, NHL and HL have been successfully established and characterized. Highly individual response to the treatments were observed, correlation analyses with mutations and gene expression are ongoing.

Our newly and extensively characterized PDX models from hematologic malignancies are suitable tools for preclinical drug development. They provide an exceptional platform for the identification and validation of new targets and allow the preclinical screening of new compounds and combinations for translational research projects.

Citation Format: Antje Siegert, Bernadette Brzezicha, Stephan Fuhrmann, Leonid Karawajew, Martin Janz, Clemens Schmitt, Iduna Fichtner, Jens Hoffmann. Patient derived xenografts of hematologic malignancies for translational research [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 1040.
Abstract 1045: Development of patient derived orthotopic xenografts from metastatic colorectal cancer
Authors: Santos Tiago Goss dos , Roque Bruno , Roque Caroline , Begnani Maria Dirlei , Lima Eduardo , Coimbra Felipe , Chojniak Rubens
Published: August 2018

The occurrence of liver metastasis is the major cause of death in colorectal cancer patients. The treatment consists of surgery and chemotherapy. However, the patient outcome is very unfavorable. Thus, the development of new therapeutic regimens to treat this condition is urgent and demand the establishment of good animal models. Among the models that have being used, the patient-derived xenografts (PDX) have emerged as one of the most promising. PDXs are preclinical models that faithfully represent the individuality of human cancer, by grafting fresh human tumor in severely immunodeficient mice which allows for higher tumor implantation rates and growth. Metastatic disease could be also modeled using orthotopic implantation into the affected organ. The patient-derived orthotopic xenografts (PDOX) can be interrogated for different treatment strategies based on the individualized gene signature of the human tumor, and the results can inform clinically relevant treatment strategies for the patient. With the objective to establish a PDOX from metastatic colorectal tumors in athymic nude mice, we implanted fresh tumor fragments into mouse liver parenchyma and propagated tumors from three patients which could be serially implanted in second and third mice generations. The morphological and immunohistochemical characterization indicate that xenografts recapitulate the tumor architecture and the expression of mismatch repair genes (MLH1, MSH2, MSH1, PMS2). After tumor implantation in first passage, the time of tumor growth decrease from 150-250 days to 30-100 days without loss of tumor identity. The growth of a post-transplantation lymphoproliferative disease (PTLD) was observed in one case. This pilot study was successful to establish the institutional PDX preclinical platform to study new therapeutic strategies, biomarkers of disease progression and treatment responsiveness.

Citation Format: Tiago Goss dos Santos, Bruno Roque, Caroline Roque, Maria Dirlei Begnani, Eduardo Lima, Felipe Coimbra, Rubens Chojniak. Development of patient derived orthotopic xenografts from metastatic colorectal cancer [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 1045.
Abstract 1056: Cancer avatars are sensitive diagnosticians of the pleural space
Authors: Kuzmishin Gwendolyn B. , Gopal Priyanka , Abazeed Mohamed E.
Published: August 2018

The identification of malignant cells in pleural fluid has critical prognostic and therapeutic implications but is frequently a diagnostic challenge. The first step in determining the cause of a suspected malignant pleural effusion, thoracentesis, has an unsatisfying low sensitivity (~60-70%). Patient-derived xenografts (PDX) retain the principal characteristics of the tumor of origin. However, there has been little progress in the application of these models to guide diagnostic and staging strategies. We assessed the feasibility, cellular yield and comparative diagnostic accuracy of pleural-derived xenografts in patients with effusions.

An institutional review board-approved single-institution prospective registry of patients was used to identify patients undergoing diagnostic and/or therapeutic thoracentesis. Cells isolated from the pleural fluid of these patients were injected into NSG mice. A diagnosis of the cancer in the xenograft was confirmed by a staff pathologist with expertise in the correspondent cancer type.

All of the cases that were clinically positive for tumor cells in the pleural space demonstrated tumor engraftment. Samples taken from patients with known benign etiologies did not result in tumor engraftment. The developed xenografts provided ample tissue that can be made available for extensive molecular testing, even in cases where the cytological samples consisted of very few cells. Critically, two of 10 cases resulted in engraftment of the tumor despite no evidence of malignant cells on cytological examination, indicating a 20% improvement in the statistical power of pleural-based xenografting for the detection of malignancy.

Our study indicates that pleural-derived xenografts can enhance the sensitivity of malignant cell detection, reflecting the inherent limitations of cytological analyses of a few malignant cells. Moreover, the amplification of cellular material provides ample source material that can be used to satisfy the increasing demands for tissue-based molecular testing. To our knowledge, this is the first effort to effectively use patient-derived xenografts for the purpose of cancer staging and diagnosis.

Citation Format: Gwendolyn B. Kuzmishin, Priyanka Gopal, Mohamed E. Abazeed. Cancer avatars are sensitive diagnosticians of the pleural space [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 1056.
Abstract 1063: A clear cell renal cancer metastasis model identifies novel mediators of tumor aggressiveness and predictors of patient survival
Authors: Geist Felix , Dolt Teresa , Höfner Thomas , Klein Corinna , Vogel Vanessa , Stenzinger Albrecht , Holland-Letz Tim , Kossi Ornella , Weichert Wilko , Schirmacher Peter , Pahernik Sascha , Hohenfellner Markus , Trumpp Andreas , Sprick Martin
Published: August 2018

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma with a 5-year survival rate of only 10.5%, and chemotherapy and radiotherapy regimen have shown limited efficacy. On the molecular level, significant inter- and intra-tumor heterogeneity hamper identification of drug targets, biomarkers and unraveling of disease mechanisms.

We developed a novel patient-derived model system of ccRCC that recapitulates the heterogeneity of the originating cancer enabling us to study ccRCC on a functional level. In five rounds and in three biological replicates of an in vivo selection, we transplanted the metastases of orthotopically transplanted tumor cells into the renal capsules of NOD scid gamma (NSG) mice. The tumor was enriched for cells with higher growth and metastatic potential compared to the initial heterogeneous population. Comparative gene-expression analysis revealed candidate genes associated with enhanced malignant growth and metastasis. Absolute shrinkage and selection operator (LASSO) regression identified a gene signature that can robustly predict patient survival. The prognostic power of our signature was additionally verified in independent patient cohorts suggesting that this approach leverages efficient stratification of patients into distinctive risk groups.

One of the hallmark genes in this signature is known to alter cellular signaling properties. Therefore, we hypothesized that this gene contributes to tumor growth and metastasis and thus to aggressiveness of ccRCC. In fact, in knockdown and overexpression xenografts experiments we could confirm an essential role for tumor aggressiveness in vivo suggesting that the gene and associated downstream signaling pathways are attractive targets for treatment of clear cell renal cancer.

Citation Format: Felix Geist, Teresa Dolt, Thomas Höfner, Corinna Klein, Vanessa Vogel, Albrecht Stenzinger, Tim Holland-Letz, Ornella Kossi, Wilko Weichert, Peter Schirmacher, Sascha Pahernik, Markus Hohenfellner, Andreas Trumpp, Martin Sprick. A clear cell renal cancer metastasis model identifies novel mediators of tumor aggressiveness and predictors of patient survival [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 1063.
Abstract 1068: LAMB3 mediates metastatic tumor behavior in papillary thyroid cancer by regulating c-MET/Akt signals
Authors: Chang Jae Won , Koo Bon Seok
Published: August 2018

Laminin subunit beta-3 (LAMB3) encodes one of the three subunits of LM-332, a protein of the extracellular matrix secreted by cultured human keratinocytes. While LAMB3 is involved in the invasive and metastatic abilities of several tumor types, including those found in the colon, pancreas, lung, cervix, stomach, and prostate, its mechanism of action in thyroid cancer has not been investigated previously. Our results show that LAMB3 is upregulated in papillary thyroid cancer, and that its suppression reduces cell migration/invasion via downregulation of epithelial–mesenchymal transition-associated proteins (N-cadherin, vimentin, slug) and inhibition of matrix metalloproteinase 9. LAMB3 suppression also significantly decreases Akt phosphorylation and inhibits the transcription of c-MET, reducing its activation. These results suggest that LAMB3 leads to tumor invasion via Akt activation induced by the HGF/c-MET axis in papillary thyroid cancer cells. Our findings reveal a novel mechanism of action for LAMB3 in papillary thyroid cancer cells.

Citation Format: Jae Won Chang, Bon Seok Koo. LAMB3 mediates metastatic tumor behavior in papillary thyroid cancer by regulating c-MET/Akt signals [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 1068.
Abstract 1082: Loss of desmoglein 2 promotes tumor growth and progression through the activation of Src and facilitates the internalization of EGFR in biliary tract carcinoma cells
Authors: Lee Sang-Hyun , Min Jeong-Ki
Published: August 2018

Understanding the molecular carcinogenesis pathways is critical to establish novel individualized molecular targeted therapies and finally to improve overall clinical outcomes of patients with a highly heterogeneous group of malignancies such as biliary tract cancers (BTCs). In this context, we investigated the patho-physiological roles of a desmosomal component, desmoglein 2 (Dsg2) and found that Dsg2 functions as a tumor suppressor protein in BTC, as Dsg2 loss induced a number of cellular biological activities including proliferation, motility, invasion, transendothelial migration in vitro and tumor growth and metastasis in vivo. Clinico-pathological analyses of BTC patients indicated that lower expression of Dsg2 is associated with a poor prognosis of patients as perineural and lymphatic invasion were highly increased in those patients. In addition, loss of Dsg2 showed a significant increase of EGFR clearance from the cell membrane in BTC cells and patients' tumor tissues. Those cells were significantly decreased in the EGF-driven activation of EGFR and highly resistant to the anti-EGFR antibody treatment. Src appears to be involved in the Dsg2-mediated clearance of EGFR, as this significantly blocked by the suppression of cSrc expression in Dsg2-depleted cells, possibly through the direct binding of Dsg2 preferentially with an inactive form of Src through its SH2 domain. Suppression of cSrc by Src inhibitors or siRNA dramatically reduced BTC tumor growth in vitro and in vivo. In comparison with the anti-EGFR antibody therapy, Src-targeted therapies produced consistent anti-tumor activities independent with the expression status of EGFR in the BTC tumors. In conclusion, targeting Src would be a promising therapeutic approach to patients with advanced BTC and potentially useful in overcoming resistance to current anti-EGFR therapies, although further clinical studies are essentially required to translate the current preclinical knowledge into clinical practice.

Citation Format: Sang-Hyun Lee, Jeong-Ki Min. Loss of desmoglein 2 promotes tumor growth and progression through the activation of Src and facilitates the internalization of EGFR in biliary tract carcinoma cells [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 1082.
Abstract 1089: Role of high mobility group A2 (HMGA2) in prostate cancer
Authors: Hawsawi Ohuod A. , Burton Liza , Dougan Jodi , Millena Ana Cecillia , Nagappan Peri , Khan Shafiq , Odero-Marah Valerie
Published: August 2018

Prostate cancer is the most highly diagnosed cancer in men and the second leading cause of death in the United States. Epithelial-mesenchymal transition (EMT) plays a critical role in cancer progression and metastasis. High mobility group A (HMGA2), a non-histone protein, has been shown to promote EMT in separate studies. Interestingly, wild-type HMGA2 and truncated (lacking the 3'UTR) HMGA2 isoforms are overexpressed in many cancers, but have not been investigated in prostate cancer. Jun-D is a transcriptional factor that might be regulated by HMGA2. Moreover, the function for each individual isoform is still not well understood. We hypothesize that each of the two isoforms of HMGA2 in will have different functions in prostate cancer. We stably overexpressed wild-type HMGA2 and truncated HMGA2 in LNCaP cells and measured the expression and the localization of EMT markers. We also measured reactive oxygen species (ROS) levels using DCFDA dye, since ROS has been associated with EMT. We performed migration and cell viability assays as well as Jun-D knockdown, a putative downstream effector of HMGA2. Our results showed that the overexpression of HMGA2 in LNCaP cells led to an increase in cell viability and migration for both wild-type and truncated HMGA2. We observed that wild-type, but not truncated HMGA2 promoted EMT. Additionally, Jun-D and ROS levels increased for truncated, but not significantly for wild-type HMGA2. Jun-D knockdown with siRNA decreased ROS and cell migration in cells with truncated HMGA2, but not in cells overexpressing wild-type HMGA2. Therefore, wild-type HMGA2 is the isoform that induces EMT, while the truncated form appears to have an alternate role in upregulating ROS via Jun-D. In conclusion, we show a link between HMGA2 and JunD/ROS for the first time, and data that wild-type and truncated HMGA2 may have differing functions that converge to increase cell proliferation and migration, and may in future instruct on more precise therapeutic targeting in patients with these isoforms.

GRANT SUPPORT: NIH 1P20MD002285 and NIH/NCRR/RCMI G12RR003062-22

Citation Format: Ohuod A. Hawsawi, Liza Burton, Jodi Dougan, Ana Cecillia Millena, Peri Nagappan, Shafiq Khan, Valerie Odero-Marah. Role of high mobility group A2 (HMGA2) in prostate cancer [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 1089.
Abstract 1101: Visualization of epithelial-mesenchymal transition in inflammatory microenvironment-colorectal cancer network in vitro and in vivo
Authors: Tazawa Hiroshi , Ieda Takeshi , Yano Shuya , Kikuchi Satoru , Kuroda Shinji , Ohara Toshiaki , Noma Kazuhiro , Kishimoto Hiroyuki , Nishizaki Masahiko , Kagawa Shunsuke , Saitou Takashi , Imamura Takeshi , Fujiwara Toshiyoshi
Published: August 2018

Background: Epithelial-mesenchymal transition (EMT) is a biologic process by which epithelial cancer cells acquire mesenchymal phenotype with malignant properties for invasion and metastasis, leading to poor prognosis. Inflammatory microenvironment has been shown to be responsible for the development and progression of colorectal cancer (CRC). However, the precise role of inflammatory microenvironment in the EMT-related tumor progression remains unclear because EMT network is regulated by complex crosstalk between tumor and normal cells. In this study, we developed a fluorescence-guided live-cell imaging system for the spatiotemporal visualization of EMT state, and assessed the in vitro and in vivo visualization of EMT state in human CRC cells under the inflammatory microenvironment.

Methods: We used two human CRC cell lines, HCT116 and RKO. The promoter of mesenchymal marker vimentin was used for inducing the EMT-dependent red fluorescence protein (RFP) expression in human CRC cells. The RFP expression was quantitatively analyzed to evaluate its association with EMT-related markers and malignant phenotype. Inflammatory cytokines, IL-1β (1 ng/ml) and TNF-α (20 ng/ml), or co-culture with inflammatory mouse macrophage cell line RAW264.7 stimulated by lipopolysaccharide (LPS) (200 ng/mL) were used as an inflammatory microenvironment. Biodistribution of EMT cells was analyzed using in vivo experiments with primary and metastatic CRC xenograft tumors.

Results: Inflammatory cytokines reversely induced the RFP expression in association with EMT-related malignant phenotype, such as morphologic change, EMT marker modulation, and invasion ability, in HCT116 and RKO cells. Co-culture with LPS-stimulated inflammatory macrophages also induced the RFP expression by secreting inflammatory cytokines. In vivo experiments revealed that EMT cells were detected within tumor tissues at colon, liver and peritoneum.

Conclusions: Our results suggest that inflammatory microenvironment has a great potential to induce EMT program in CRC cells. This fluorescence-guided EMT imaging system is a useful tool for monitoring the EMT state in the inflammation microenvironment-CRC network in vitro and in vivo.

Citation Format: Hiroshi Tazawa, Takeshi Ieda, Shuya Yano, Satoru Kikuchi, Shinji Kuroda, Toshiaki Ohara, Kazuhiro Noma, Hiroyuki Kishimoto, Masahiko Nishizaki, Shunsuke Kagawa, Takashi Saitou, Takeshi Imamura, Toshiyoshi Fujiwara. Visualization of epithelial-mesenchymal transition in inflammatory microenvironment-colorectal cancer network in vitro and in vivo [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 1101.
Abstract 1104: Tumor-associated macrophages-secreted CXCL1 promotes breast cancer metastasis via activating NF-κB/SOX4 signaling
Authors: Wang Zhiyu , Wang Neng , Liu Weiping , Zheng Yifeng , Wang Shengqi
Published: August 2018

Purpose: Secreted cytokines play a significant role in modulating cancer metastatic microenvironment, especially for tumor associated macrophages (TAMs). The current study aimed to determine the significance of TAMs-secreted CXCL1 in regulating cancer metastasis and its underlying mechanisms. Experimental Design: Cytokine array was utilized to screen the highest chemokine secreted from TAMs. In vivo immunohistochemistry assay and in vitro wound healing or transwell experiments were carried out to demonstrate the metastatic-promoting effects of TAMs/CXCL1. QPCR profile screening was used to identify CXCL1 targeting metastasis-related gene. In vivo luciferase imaging experiments were designed to confirm the therapeutic significance of CXCL1 silencing on breast cancer metastasis. The clinical significance of CXCL1 was analyzed by human tissue microarray and bioinformatic analysis. Results: CXCL1 was validated as the highest secreted protein released from TAMs, and TAMs-derived CXCL1 could promote breast cancer migration and invasion ability, as well as epithelial-mesenchymal transition (EMT) process. QPCR screening validated SOX4 as the most responsive gene following CXCL1 administration. Mechanistic study revealed that CXCL1 activates SOX4 transcription via NF-κB pathway. CXCL1 silencing in TAMs resulted in a significant reduction in breast cancer growth and metastatic burden. Clinical investigation suggests that high CXCL1 expression was significantly correlated with breast cancer lymph node metastasis, poor overall survival and basal-like subtype. Conclusions: TAMs/CXCL1 promotes breast cancer metastasis via NF-κB/sox4 activation, and CAV1 based therapy might become a novel strategy for breast cancer metastasis prevention.

Citation Format: Zhiyu Wang, Neng Wang, Weiping Liu, Yifeng Zheng, Shengqi Wang. Tumor-associated macrophages-secreted CXCL1 promotes breast cancer metastasis via activating NF-κB/SOX4 signaling [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 1104.
Abstract 1108: M2-polarized macrophages increase invasiveness of EBV-associated nasopharyngeal carcinoma by inducing invadopodia formation
Authors: Tang Wilson Wing Chung , You Chan Ping , Jones Gareth E. , Tsao George Sai-Wah , Tsang Anna Chi Man
Published: August 2018

Cancer metastasis is a major cause of mortality, accounting for approximately 90% of cancer related deaths. Emerging evidences suggest that tumour microenvironment plays an indispensable role in cancer metastasis. Recruitment of innate and adaptive immune cells to the tumour results in chronic inflammation which favours tumour growth and progression. Particularly, tumour associated macrophages (TAMs) are found to promote the initiation, growth, and metastasis in several types of cancers. Nasopharyngeal carcinoma (NPC) is one of the highly invasive and metastatic cancers and is closely associated with EBV infection. We postulate that TAMs may increase the invasiveness of NPC by enhancing the formation of invadopodia, which are membranous actin-rich protrusions with digestive ability of extra-cellular matrix. In this study, monocyte THP-1 cells were polarized to M2-macrophages, and co-cultured with nasopharyngeal cells in a contained chamber-insert. The stimulated nasopharyngeal cells then formed massive numbers of invadopodia and digested larger area of gelatin compared with the unstimulated counterparts. A cytokine antibody array was used to identify the upregulated cytokines in the co-culture medium of the M2-macrohphages and the NPC cells. Tumour necrosis factor alpha (TNFα) was revealed to be the responsible cytokine to induce the formation of invadopodia and digestion of gelatin. Besides, western blot analysis identified that several actin-associated proteins such as Src, Erk, and cortactin were involved in the TNFα-mediated invadopodia formation. We also found that the expression of latent membrane protein 1 (LMP1), an EBV protein that has similar structure to TNF receptor was elevated in NPC cells after co-culturing with the M2-polarized macrophages. Through transient transfection and stable expression of LMP1 in the NPC cells, LMP1 could also promote the formation of invadopodia through cdc42 activation. Taken together, these data indicate macrophages can promote the invasiveness of EBV-infected NPC cells by enhancing their ability in forming invadopodia through an activated TNFα signaling axis and LMP1 upregulation.

Citation Format: Wilson Wing Chung Tang, Chan Ping You, Gareth E. Jones, George Sai-Wah Tsao, Anna Chi Man Tsang. M2-polarized macrophages increase invasiveness of EBV-associated nasopharyngeal carcinoma by inducing invadopodia formation [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 1108.
Abstract 111: The CX3CR1-Fractalkine axis drives both circulating prostate cancer cells and macrophages to the bone metastatic microenvironment
Authors: Kaur Ramanpreet , Qian Chen , Salvino Joseph , Meucci Olimpia , Fatatis Alessandro
Published: August 2018

Prostate cancer (PCa) is the second most frequently diagnosed cancer and its progression into metastatic disease reduces the 5-year survival rate to 29% in diagnosed men. A better understanding of the mechanisms underpinning metastatic dissemination and the role played by the tumor microenvironment at distant sites is essential. Our lab has shown that PCa cells express the chemokine receptor CX3CR1 and seed the skeleton when attracted by bone-derived Fractalkine (FKN) (a.k.a. CX3CL1). A crucial component of the bone microenvironment consists of heterogeneous populations of tumor-associated macrophages (TAMs), which can polarize into M1 or M2 phenotypes and are likely implicated in metastatic progression. TAMs migrate in close proximity of cancer cells and release growth factors, chemokines, and other inflammatory mediators that influence tumor growth. Using cell biology tools, we show that both PCa cells and macrophages express the CX3CR1 receptor, which signal to downstream targets when engaged by FKN and is inhibited by a novel small-molecule inhibitor. We also employed a mouse model of cancer cell dissemination and metastasis to show that our novel CX3CR1 antagonist impairs tumor seeding to the skeleton. Furthermore, as macrophages also express CX3CR1, targeting this receptor may potentially hinder TAMs' accumulation into the metastatic microenvironment, depriving it of crucial pro-metastatic conditioning. In conclusion, we propose that the CX3CR1-FKN axis drives both cancer cells and TAMs to metastatic sites and that the mitigation of the functional interactions between this receptor and its unique chemokine ligand by antagonists of CX3CR1 will impair the clinical progression of PCa metastasis.

Citation Format: Ramanpreet Kaur, Chen Qian, Joseph Salvino, Olimpia Meucci, Alessandro Fatatis. The CX3CR1-Fractalkine axis drives both circulating prostate cancer cells and macrophages to the bone metastatic microenvironment [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 111.
Abstract 1112: AKT2 loss impairs BRAF mutant melanoma metastasis
Authors: McRee Siobhan K. , Pietruska Jodie R. , Tsichlis Philip N. , Hinds Phil W.
Published: August 2018

Despite recent advances in treatment, melanoma remains the deadliest form of skin cancer, due to its highly metastatic nature. Many melanomas with oncogenic BRAFV600E lose the tumor suppressor PTEN, leading to unconstrained PI3K/AKT signaling and a drastic increase in melanoma invasiveness, but the contribution of AKT to melanoma metastasis has not been fully explored. Differential roles for AKT1 and AKT3 have been suggested in many cancers, but a requirement for AKT2 has not been described in melanoma. We report here that shRNA-mediated, conditional knockdown of AKTs in a variety of human melanoma cell lines reveals that selective AKT2 depletion inhibits migratory and invasive phenotypes in vitro, and prevents metastasis in vivo. Our results support a critical role for AKT2 in stimulating melanoma cell migration and invasion and in supporting growth of metastatic lesions. As AKT inhibitors advance in clinical trials for melanoma, our findings could inform therapeutic strategies to improve treatment options and outcome for this devastating disease.

Citation Format: Siobhan K. McRee, Jodie R. Pietruska, Philip N. Tsichlis, Phil W. Hinds. AKT2 loss impairs BRAF mutant melanoma metastasis [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 1112.
Abstract 1113: PODXL1 as a critical accelerator for pancreatic cancer metastasis
Authors: Kondo Eisaku , Saito Ken
Published: August 2018

Podocalyxin-like 1 (PODXL1) is an anti-adhesive transmembrane protein belonging to the CD34 family and also stem cell marker that has been associated with an aggressive tumor phenotype and poor prognosis in several forms of cancer. In this study, we report the biological role of PODXL1 in progression of pancreatic invasive ductal adenocarcinoma (PDAC), especially focusing to invasion and metastasis of PDAC cells. Knockout of PODXL1 gene in three different human PDAC lines, MiaPaCa-2, AsPC1 and Panc-1, almost completely abrogated metastatic lesion in liver-metastatic mouse model in vivo. Molecular analysis revealed that PODXL1 functioned as a critical activator to multiple cytokine receptors expressed on cancer cells, and its interaction facilitated PDAC cell invasion. Endogenous expression of PODXL1 was strongly detected on cancer cells at the invasive front of the PDAC tissues, where coincidently expressed specific cytokine receptor that critically mediates cancer metastasis in vivo. Thus, we identify the novel functional aspect of PODXL1 and its biological role on PDAC as one of the most intractable malignancies.

Citation Format: Eisaku Kondo, Ken Saito. PODXL1 as a critical accelerator for pancreatic cancer metastasis [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 1113.