bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B082: Role of CD44v6 in acquired resistance to anti-angiogenic therapy of triple-negative breast cancer
Authors: Morello Virginia , Ginestier Christophe , Charafe-Jauffret Emmanuelle , Michieli Paolo
Published: May 2015

Triple-negative breast tumors do not offer many therapeutic opportunities beyond chemotherapy. Lately, new hope for the treatment of this type of cancer has been brought by anti-angiogenic agents. However, clinical trials showed that, although angiogenesis inhibitors increase progression-free survival of triple negative cancer patients, they do not improve overall survival, suggesting the occurrence of acquired resistance. Understanding the molecular mechanisms underlying resistance to angiogenesis inhibitors is an important step towards the development of therapies that prevent this process. Using a vital library of human primary breast cancers, we developed an orthotopic mouse model of triple negative carcinoma that allows studying acquired resistance to angiogenesis inhibitors in a controlled setting. This model unveiled that anti-angiogenic drugs reduce tumor growth on one hand but enhance metastasis on the other. FACS analysis of tumor cells revealed that angiogenesis inhibitors enrich for cells expressing CD44v6, a splice variant of the trans-membrane glycoprotein CD44. Expression of CD44v6 has been associated with tumor invasion and metastasis in a variety of human cancers, including breast. Furthermore, CD44v6 has been shown to be a co-receptor for Hepatocyte Growth Factor (HGF) and to be essential for the activation of c-Met, a master regulator of invasive growth. Interestingly, treatment with HGF/Met inhibitors reduced tumor growth, prevented selection of CD44v6+ cells and suppressed angiogenesis inhibitor-induced metastasis. These results point at a causative role of CD44v6 in acquired resistance to anti-angiogenic therapy and suggest the opportunity of combining HGF/Met inhibitors with anti-angiogenic drugs.

Note:This abstract was not presented at the conference.

Citation Format: Virginia Morello, Christophe Ginestier, Emmanuelle Charafe-Jauffret, Paolo Michieli. Role of CD44v6 in acquired resistance to anti-angiogenic therapy of triple-negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B082.
Abstract B087: HER-2/neu expression regulates the immune response and tumor senescence in breast cancer
Authors: Rosemblit Cinthia , Cintolo-Gonzalez Jessica , Xu Shuwen , Czerniecki Brian J.
Published: May 2015

Background: Over-expression of the receptor tyrosine kinase ErbB2 (HER-2) has been widely implicated in malignant transformation, cell survival, motility and invasion in breast cancers. Intermediate expression of HER-2 has been identified in luminal breast cancer stem cells. HER-2 over-expression down regulates major histocompatibility complex class I molecules (MHCI) expression in breast cancer cells.

Results: We investigated the expression of HER-2 in various HER-2 expressing cell lines and measured HLA A-2 MHC class I expression. High Her-2 expressing cell lines SKBR3 and SKOVA3 and intermediate expressing cell lines MCF7 demonstrated extremely low HLA A-2 expression, while low Her-2 expressing MDAMB231 demonstrated low HER-2 expression and high HLA A2 expression. Anti-HER-2 CD8 T cells recognize the latter cells but not high or intermediate expressing HER-2 expressing cells. Treatment of intermediate expressing cell lines but not high HER-2 expressing cells with interferon-gamma; (IFN- gamma) and TNF-alpha; result in markedly increased HLA A2 expression and 3 fold increase in CD8 T cell killing of the MCF7 cells. Treatment of high expressing HER-2 cells with trastuzumab but not lapatinib decreased HER-2 expression and combined with IFN-gamma; and TNF-alpha; result in increased HLA- A2 expression and dramatic increase in CD8 T cell recognition. In contrast, high and intermediate HER-2 expressing cells are sensitive to lysis and tumor senescence induction when treated with combinations of IFN-gamma; and TNF-alpha; in a dose dependent manner. Low HER-2 expressing cells are less sensitive to senescence induction.

Conclusions: In conclusion, our results establish a potential role for HER-2 in regulating the immune response against breast cancer and suggest that CD8 T cells are more effective in eliminating low and intermediate HER-2 expressing cells while CD4 T cell derived IFN-gamma; and TNF-alpha; together with trastuzumab may be more effective in eliminating high expressing HER-2 breast cancer cells and inducing tumor senescence preventing recurrence.

Citation Format: Cinthia Rosemblit, Jessica Cintolo-Gonzalez, Shuwen Xu, Brian J. Czerniecki. HER-2/neu expression regulates the immune response and tumor senescence in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B087.
Abstract B091: Analysis of glial activation in a murine model of brain metastatic breast cancer
Authors: Shapovalov Yuriy , Amico-Ruvio Stacy A. , Spielman Sara C. , Lamantia Cassandra E. , Brown Edward B. , Majewska Ania K.
Published: May 2015

Brain metastasis represents a particularly challenging complication of breast cancer. It is estimated that in certain populations of cancer patients, approximately 10-15% have symptomatic brain metastases and as many as 30% reveal metastases on autopsy. The brain provides a unique microenvironment for tumor growth. It is a particularly difficult therapeutic target due to the complexity of brain function as well as the reduced access of therapeutic agents through the blood brain barrier (BBB). In fact, many of the newest and most effective treatments for primary breast cancer are ineffective in treating tumor metastases in the brain. It is becoming increasingly clear that prevention and treatment of brain metastatic breast cancer requires development of new, brain-specific treatments which can take into account this unique metastatic milieu and exploit innate mechanisms to fight tumor cell seeding, extravasation, and growth in the brain.

In this study, we characterized pattern of glial activation in a murine model of brain metastatic breast cancer. We used a human breast adenocarcinoma cell line, MDA-MB-231BR-GFP, that exhibits selective metastatic tropism toward the brain. Three weeks after intracardiac injection of the cells into Nu/Nu mice, we observed the development of brain metastases. Using immunohistochemistry, we analyzed expression of glia-specific markers in the immediate vicinity of and away from metastatic breast tumors. We discovered that microglia and astrocytes are activated in the areas adjacent to tumor cells. The degree of activation diminishes considerably away from the tumors.

The experimental data provide an insight into the pattern of glial activation in the setting of brain metastatic breast cancer. The results of our experiments also necessitate additional studies to improve our understanding about breast tumor metastasis to the brain. We are currently investigating mechanisms whereby glial activation may promote increased metastatic seeding of breast cancer cells. Our research focus has been on pro-inflammatory markers as potential mediators of glial activation on the entry of cancer cells to the brain. In addition, we have been examining possible contribution of glia in the disruption of the BBB and the increase in brain metastasis of breast cancer. These results provide a starting point for evaluating whether glia may directly contribute to breast cancer metastasis to the brain.

Citation Format: Yuriy Shapovalov, Stacy A. Amico-Ruvio, Sara C. Spielman, Cassandra E. Lamantia, Edward B. Brown, III, Ania K. Majewska. Analysis of glial activation in a murine model of brain metastatic breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B091.
Abstract B092: Beta-blockade of breast cancer metastasis: Receptor regulation and downstream signaling pathways
Authors: Chai Ming Gene , Le Caroline P. , Creed Sarah J. , Finnin Benjamin A L , Pimentel Matthew A. , Shackleford David , Moeller Andreas , Haviv Izhak , Lane J. Robert , Sloan Erica K.
Published: May 2015

Chronic stress accelerates breast cancer metastasis through beta-adrenergic signaling and recent clinical studies found that beta-blockade reduced metastasis in women with breast cancer. However, the specific beta-adrenergic receptor subtype(s) through which stress-responsive neurotransmitters mediates effects on cancer remain unknown. To identify the receptor that transmits beta-adrenergic signaling to primary mammary tumors, we used bioluminescence imaging to longitudinally quantify the effect on metastasis of beta-blockers that selectively inhibit beta1 vs. beta 2 adrenergic receptors in an orthotopic mouse model of breast cancer progression. Non-specific beta-blockade with propranolol reduced metastasis by >90% (p = .03), confirming a key role for beta-adrenergic signaling pathways in stress-enhanced metastasis. Treatment with the beta2-selective antagonist ICI118551 similarly reduced stress-enhanced metastasis to control levels. In contrast, beta-1 selective blockade failed to protect against metastasis. Pharmacological intervention studies and gene expression analyses have started to define the downstream signaling pathways of beta-adrenergic regulation of metastasis. These studies may provide mechanistic explanation for recent clinical findings that not all beta-blockers protect against metastasis and provide a framework for selection of cancer patients who may optimally benefit from beta-blockade.

Citation Format: Ming Gene Chai, Caroline P. Le, Sarah J. Creed, Benjamin A L Finnin, Matthew A. Pimentel, David Shackleford, Andreas Moeller, Izhak Haviv, J. Robert Lane, Erica K. Sloan. Beta-blockade of breast cancer metastasis: Receptor regulation and downstream signaling pathways. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B092.
Abstract B100: Subtype specific expression of HRH1 contributes to increased chemoresistance of breast cancer cells
Authors: Mancino Mario , Fernandez-Nogueira Patricia , Enreig Estel , Ametller Elisabet , Gascón Pedro , Almendro Vanessa
Published: May 2015

Background: Histamine is a monoamine produced by α-decarboxylation of histidine by the enzyme histidine decarboxylase (HDC). Histamine acts as an autocrine regulator of cell proliferation through its binding to HRH1-4 receptors. In breast cancer (BC), there are controversial results about the therapeutic efficacy of HRH1 or HRH2 inhibitors and the role of histamine receptors in tumor progression.

Given the phenotypic heterogeneity of BC and the presence of different molecular subtypes with different clinical outcome, we aimed to investigate the contribution of histamine receptors in the proliferation, migration and cell survival of BC cells of different molecular subtypes.

Methods: The expression of histamine receptors HRH1-4 and HDC in human breast tumors of different subtypes, and their correlation with clinical variables were gathered through informatics analysis using the “Gene expression based Outcome for Breast cancer Online” (GOBO) web-based tool. The measurement of the mRNA levels of HRH1-4 and HDC in a panel of breast cancer cell lines was used to confirm the subtype specific expression of each protein. Using specific HRH inhibitors in luminal and basal-like breast cancer cell lines we assessed the functional role of histamine receptors in cell proliferation, migration and survival.

Results: HRH1 was highly expressed in ER+ tumors while HDC was highly expressed in the ER- tumors. In any case, the high expression of HRH1 or HDC was significantly correlated with lower overall survival only in ER+ tumors. The same pattern of expression was observed in BC cell lines, where HRH1 was highly expressed in basal-like BC cells compared to the luminal ones. HRH2 and HRH3 were highly expressed in the estrogen-dependent MCF7 cell line, while HRH4 was not detected in any breast cancer cell line. Only the antagonism of HRH1 induced apoptosis, and decreased proliferation and migration, while HRH2 or HRH3 inhibition had no effect on cell survival. Interestingly, the luminal cell lines were more sensitive than the basal-like cell lines to HRH1 antagonism, even though the low expression of HRH1 in these cells.

Conclusion: Taken together, these findings suggest a complex role of the autocrine histamine signaling system in the progression of BC tumors of different subtype through the activation of HRH1.

Citation Format: Mario Mancino, Patricia Fernandez-Nogueira, Estel Enreig, Elisabet Ametller, Pedro Gascón, Vanessa Almendro. Subtype specific expression of HRH1 contributes to increased chemoresistance of breast cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B100.
Abstract B107: STAT3-induced production of hyaluronan contributes to FGFR-induced migration, proliferation, and therapeutic resistance in breast cancer
Authors: Bohrer Laura , Chuntova Polly , McCarthy James , Schwertfeger Kaylee
Published: May 2015

Aberrant activation of fibroblast growth factor receptors (FGFRs) has been linked to breast cancer growth and progression. FGFR activation in tumor cells acts through both autocrine and paracrine mechanisms to contribute to tumor growth. Our previous studies suggesting that FGFR activation leads to increased inflammation led us to evaluate the mechanisms that drive FGFR-induced inflammation in the tumor setting. We demonstrate here that FGFR activation leads to phosphorylation of STAT3Tyr705 in a number of breast cancer cell lines. Furthermore, we demonstrate that phosphorylation of STAT3Tyr705 is mediated indirectly through FGFR-induced production of IL-6 family cytokines. Using a novel in vivo model of FGFR-dependent tumor growth, we demonstrate that pharmacological inhibition of STAT3 leads to decreased FGFR tumor growth. Further examination of the function of STAT3 in this model revealed that STAT3 regulates expression of hyaluronan synthase 2 (Has2) and subsequent production of the extracellular matrix component hyaluronan (HA). Increased HA production by the tumor cells was found to contribute to FGFR-induced proliferation, migration and therapeutic resistance. Finally, analysis of human breast cancer samples reveals a correlation between activated FGFR signaling and tumor-associated expression of HA. In conclusion, our studies demonstrate that FGFR activation leads to STAT3 activity, which regulates expression of Has2 and production of tumor cell-derived HA. Together, these results identify a novel pathway by which FGFR induces proinflammatory signaling pathways and modifies the microenvironment, leading to enhanced FGFR-induced tumor growth.

Citation Format: Laura Bohrer, Polly Chuntova, James McCarthy, Kaylee Schwertfeger. STAT3-induced production of hyaluronan contributes to FGFR-induced migration, proliferation, and therapeutic resistance in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B107.
Abstract B118: An efficient resource to accelerate research into the cause and prevention of breast cancer: The Love Army of Women
Authors: Love Susan M.
Published: May 2015

Background: It is well established that more research into the cause and prevention of breast cancer is needed. While studies are done in cell lines and lab animals, translation of findings to women is often delayed due to difficulty in recruitment. To address this problem, the Dr. Susan Love Research Foundation formed the Love Army of Women (AOW); an on-line recruitment resource designed to partner women with researchers in order to accelerate breast cancer research.

Methods: Researchers submit a proposal to the Dr. Susan Love Research Foundation's Scientific Advisory Committee. If a study is accepted, a mass e-mail describing the study procedures and inclusion/exclusion criteria is sent to the entire AOW database. Women sign up at www.armyofwomen.org to join and receive AOW e-mails about breast cancer research studies. Women self-select based on interest and study criteria, and undergo a secondary on-line screening before contact information is passed on to the researcher for the enrollment process.

Results: Over 373,000 women have signed up, including survivors and women without a history of breast cancer, ranging from ages 18 to 100, representing all 50 US states and 49 countries. To date, the AOW has recruited for 76 studies. The diversity of the AOW members has proved beneficial for many studies, such as those needing to enroll racial/ethnic minorities, women of varying sexual orientations, or young survivors.

A secondary goal of the AOW is to assist researchers new to research with human subjects. The AOW has successfully helped researchers cross the chasm, coaching them on what it takes to transition their research from animal models to human subjects.

Conclusions: The AOW has proved to be a successful resource for scientists to accelerate accrual, expand the number and diversity of their subject population and to obtain exactly the type of specimens they need when they need it. This partnership between women and scientists has revolutionized research and accelerated efforts to eradicate breast cancer. The public is ready and willing to partner with the research community to find the answers to urgent clinical problems.

Citation Format: Susan M. Love. An efficient resource to accelerate research into the cause and prevention of breast cancer: The Love Army of Women. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B118.
Abstract B133: Metalloprotease-disintegrin ADAM12-L in breast cancer cells: Regulation of expression by microRNA-200b/c
Authors: Duhachek-Muggy Sara , Zolkiewska Anna
Published: May 2015

ADAM12-L, a member of the cell surface ADAM metalloprotease family, is selectively up-regulated in claudin-low breast cancers and in residual breast tumors after conventional therapy. In vitro, ADAM12-L is enriched in breast cancer cells grown in suspension as mammospheres and after induction of epithelial-to-mesenchymal transition (EMT) by transforming growth factor β or Twist. The mechanisms responsible for this pattern of ADAM12-L expression are not known. The 3'-UTR of ADAM12-L mRNA contains several predicted target sites for miR-200b/c, important regulators of EMT, tumor invasion, metastasis, and chemosensitivity. The mRNA splice variant encoding the secreted isoform ADAM12-S and lacking miRNA-200b/c target sites in the 3'UTR shows a different expression pattern than ADAM12-L. The purpose of this study was to determine whether ADAM12-L expression in breast cancer cells is regulated by miR-200b/c. To achieve this goal, breast cancer cells with high expression of ADAM12-L and low levels of miR-200b/c (SUM159PT, SUM1315MO2, and Hs578T) were treated with miR-200b/c mimics. Cells with low expression of ADAM12-L and high levels of miR-200b/c (SUM225PT, SUM149PT, and MCF7) were treated with miR-200b/c inhibitors. To determine whether ADAM12-L mRNA is a direct target of miR-200b/c, we performed co-transfection experiments using miR-200b/c mimics/inhibitors and ADAM12-L 3'UTR reporter constructs with intact or mutated miR-200b/c target sites. Our results indicate that miR-200b/c down-regulates ADAM12-L levels in breast cancer cells, but the mechanism does not seem to involve direct targeting of its 3'UTR. As ADAM12-L is virtually not present in normal breast tissue, we propose that ADAM12-L may be considered as a novel cell surface marker of tumor cells undergoing EMT and/or as a read-out for miR-200b/c activity in breast tumors.

Citation Format: Sara Duhachek-Muggy, Anna Zolkiewska. Metalloprotease-disintegrin ADAM12-L in breast cancer cells: Regulation of expression by microRNA-200b/c. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B133.
Abstract B136: Sox10 expression labels in vitro mammary stem cell activity
Authors: Dravis Christopher , Johns Claire , Spike Benjamin T. , Smith Michelle Southard , Wahl Geoffrey M.
Published: May 2015

Molecular pathways that guide cell proliferation and programming events during embryonic development to generate specific organs may be aberrantly re-activated in the cancer state of those organs to drive tumor progression. Recently, our laboratory has successfully demonstrated the applicability of this tenet to studies of breast cancer. We have developed an enrichment protocol for fetal mammary stem cells (fMaSCs) from embryonic mammary rudiments, and verified that particular subtypes of breast cancers, including Basal-like triple-negative breast cancers for which targeted therapies do not exist, show strong correlation with expression signatures found in fMaSCs. This suggests that elucidation of the biology behind fMaSC function will yield important insight into better treatment of these aggressive breast cancers. To identify mechanisms that govern fMaSC function, we have performed transcriptome analyses on cell populations enriched for fMaSCs and their surrounding stroma. From this data, we have identified candidate signaling and transcription networks that we are currently validating. Here we describe ongoing work with one candidate to emerge from our analyses, Sox10. Sox10 is specifically expressed in the enriched fMaSC population, and is of particular interest given the well-documented roles for other Sox family transcription factors in: 1) regulating cell fate decisions in embryonic and adult tissue, and 2) mediating the progression of some types of cancer. We show that Sox10 expression specifically correlates with MaSC function in fetal and adult mammary. We further show that Sox10 expression can be utilized to identify the cells maintaining MaSC stem cell properties in culture. Importantly, incorporation of Sox10 into our existing fMaSC purification protocol results in a twofold improvement in fMaSC enrichment. Our discoveries with Sox10 thus represent a molecular focal point around which to build signaling and transcriptional networks underlying fMaSC state and function. They further demonstrate the promise of our approach in identifying novel targets for the development of new therapies for poorly treated cancers.

Citation Format: Christopher Dravis, Claire Johns, Benjamin T. Spike, Michelle Southard Smith, Geoffrey M. Wahl. Sox10 expression labels in vitro mammary stem cell activity. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B136.
Abstract IA04: Genomic studies of breast cancer progression
Authors: Mardis Elaine R.
Published: May 2015

Whole genome sequencing of tumor progression samples provides an ability to capture the natural history of cancer evolution. Hence, we can document changes in the cancer cell population by monitoring the changing genotypes detected at different stages of progression. The impact of therapeutic intervention on cancer cell heterogeneity is of interest, and can be indicative of therapy resistance or response. Metastatic progression is of interest as an evolutionary process, wherein the resulting heterogeneity of primary and metastatic tumor is of interest, as is evidence for novel drivers unique to one or more metastases. I will provide results for studies of both types, involving breast cancer samples and integrated analyses from whole genome sequencing and RNA sequencing.

Citation Format: Elaine R. Mardis. Genomic studies of breast cancer progression. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr IA04.
Abstract IA13: Wnt and Fgf signaling in mammary stem cells and breast cancer
Authors: Rosen Jeffrey M. , Bin Xue , Roarty Kevin
Published: May 2015

Some of the earliest evidence implicating both Wnt and FGF signaling in mammary tumorigenesis came from the observation of tumors in mouse mammary tumor virus (MMTV)- infected mice. Tumors arising from MMTV proviral insertion often exhibited preferential activation of Wnt and FGF pathway members. Interestingly, tumors with MMTV-induced expression of these FGF pathway ligands also showed MMTV-induced activation of Wnt pathway members, and functional cooperativity of MMTV-driven Wnt 1 and Fgf-3 transgenes in mammary tumorigenesis was observed. High throughput MMTV insertional mutagenesis studies have indicated that activation of Wnt and FGF pathway components is the most common occurrence in resulting tumors, providing definitive genetic proof for the cooperativity between these two pathways. Unraveling the complexity of these pathways in the context of development and tumorigenesis remains an evolving challenge. While the Wnt/ß-catenin cascade plays a central role in a range of biological processes, it has emerged as a key regulator of stem cell dynamics in multiple tissues, including the mammary gland. Significant evidence now implicates the Wnt/ß-catenin pathway in uncontrolled self-renewal of cancer stem cells and their associated radiation resistance during treatment. In the mammary gland, localized Wnt signaling most likely plays a critical role in regulating oriented cell division and cell fate. As with many signaling pathways, this is not an “on and off switch”, but is instead influenced by the level and duration of the signaling event. There are also Wnt-mediated ß-catenin-independent pathways, known as noncanonical Wnt cascades. For instance, noncanonical Wnt signaling through the receptor Ror2 helps to specify the extent and location of canonical Wnt/ß-catenin signaling. With regard to FGF signaling, FGFR1 and FGFR2, the two primary FGFRs expressed in mouse mammary epithelium, also are critical for mammary stem cell maintenance. Cooperation of the FGF and Wnt pathways in mammary tumorigenesis is based in part on the activation of protein translational pathways that result in, but are not limited to, increased expression of Wnt/β-catenin target genes at the level of protein translation. Lastly, Wnt and Fgf ligands can be regulated by systemic steroid hormones and act in a paracrine manner to influence mammary stem cells, providing another layer to the signaling hierarchy. Supported by grant NIH-CA16303.

Citation Format: Jeffrey M. Rosen, Xue Bin, Kevin Roarty. Wnt and Fgf signaling in mammary stem cells and breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr IA13.
Abstract PR07: Integrative functional genomics of breast cancer
Authors: Marcotte Richard , Sayad Azin , Iorio Cathy , Haider Maliha , Moffat Jason , Neel Benjamin G.
Published: May 2015

Cancer is a disease of the genome. Using genomic approaches alone, it is difficult to ascertain which variants drive pathogenesis because most of these are functionally irrelevant passenger mutations. Highly recurrent events point to drivers; however, the majority of genomic alterations in tumors occur at low frequency. In addition, the products of many oncogenes and tumor suppressor genes are not druggable. However, such abnormalities can cause unanticipated gene/pathway dependencies (synthetic lethality), providing alternate avenues for drug development. Lentiviral-based shRNA libraries enables genome-wide screening of cultured cancer cells in a pooled format, facilitating the identification of genes necessary for cancer cell proliferation and survival in cultured cells. We screened a panel of > 75 breast cancer cell lines using an 80,000 lentiviral shRNA library targeting 16,000 genes and integrated these screen results with gene expression, copy-number variation (CNV), and somatic mutations derived from the same lines. We identified several classes of gene dropouts, which are required for survival or growth of all (or some) cell lines, irrespective of subtype and several subtype-specific genes, whose essentiality is restricted to a defined subtype. These include well-known HER2 subtype-specific genes, ERBB2, ERBB3, and TFAP2C and luminal subtype-specific gene FOXA1, SPDEF, GATA3, and ESR1. In addition, the unprecedented number of lines allows the identification of synthetic lethal interaction with common breast cancer somatic mutations or CNV such as PIK3CA and PTEN or 9p21 deletion, respectively, which encodes the CDKN2A, CDKN2B, and MTAP genes. Finally, integration of gene expression, copy number variation, and functional screening results identified potential biomarkers with common genetic changes and functional drivers. Overall, our study represents an extensive functional genetic survey of breast cancer, reveals complexities between genomic and functional genomic results, and uncovers several unexpected gene dependencies and potential novel therapeutic target for each subtype.

This abstract is also presented as Poster A033.

Citation Format: Richard Marcotte, Azin Sayad, Cathy Iorio, Maliha Haider, Jason Moffat, Benjamin G. Neel. Integrative functional genomics of breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr PR07.
Abstract A08: Clonal evolution enhances leukemia propagating cell activity in T-cell acutelymphoblastic leukemia through AKT/mTORC1 pathway activation
Authors: Blackburn Jessica , Liu Sali , Dobrinski Kimberly , Martinez Sarah , Moore Finola , Lobbardi Riadh , Langenau David
Published: May 2015

This abstract is being presented as a short talk in Session 3: Mechanisms of Resistance. A full abstract is printed in the Proffered Abstracts section (PR06) of the Conference Proceedings.

Citation Format: Jessica Blackburn, Sali Liu, Kimberly Dobrinski, Sarah Martinez, Finola Moore, Riadh Lobbardi, David Langenau. Clonal evolution enhances leukemia propagating cell activity in T-cell acutelymphoblastic leukemia through AKT/mTORC1 pathway activation. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A08.
Abstract A10: Suppressor of cytokine signaling (SOCS)-3 and the C-X-C chemokines CXCL1 and CXCL2 promote tumor aggressiveness and radiation resistance in pancreatic cancer
Authors: Jiang Sisi , Coppola Giovanni , Mose Evangeline , Lowy Andrew , Jamieson Christina , Cacalano Nicholas
Published: May 2015

Despite recent advances in our understanding of pancreatic ductal adenocarcinoma (PDA), it remains a poorly understood, devastating disease that is largely resistant to all standard treatment modalities. Much effort has been made to identify novel tumor suppressor genes, biomarkers of metastatic behavior, and targets for molecular therapeutics that can improve prognosis and quality of life for PDA patients. Despite the finding that the pro-inflammatory C-X-C family chemokines CXCL1 and CXCL2 are expressed in a significant fraction of human PDA tissues and are known to promote metastasis in bladder and breast cancer, very little is known of its regulation and its role in the progression of PDA. Our laboratory has identified a mechanism by which CXCL1 and CXCL2 expression is regulated in human PDA. CXCL1/2 expression is repressed by the Signal Transducer and Activator of Transcription (STAT)-3 and conversely, the Suppressor of Cytokine Signaling (SOCS)-3, a STAT3 inhibitor, promotes CXCL1/2 gene activation and pro-inflammatory signaling in murine embryonic fibroblasts (MEFs) and human PDA cell lines. Ectopic expression of SOCS3 in the ASPC1 PDA cell line induces CXCL1 and CXCL2 expression and drives resistance to radiation and gemcitibine treatment. Treatment with neutralizing antibodies against CXCL1 or its receptor, CXCR2, sensitizes these cells to ionizing radiation. Further, using an orthotopic xenograft model of human PDA in immunodeficient mice, we demonstrated the in vivo relevance of this pathway. We found that mice injected with human SOCS3-positive human PDA cells have a shorter survival time and develop more aggressive disease compared to mice injected with control cells. We also have shown increased numbers of CD11b-positive granulocytes in the tumor microenvironment of SOCS3+ PDA tumors. We hypothesize that SOCS3 and CXCL1and CXCL2 promote human PDA pathogenesis by two mechanisms: (i) autocrine activation of the CXCR2 receptor expressed on human pancreatic cancer cells and (ii) pro-inflammatory recruitment of neutrophils to the tumor microenvironment.

Citation Format: Sisi Jiang, Giovanni Coppola, Evangeline Mose, Andrew Lowy, Christina Jamieson, Nicholas Cacalano. Suppressor of cytokine signaling (SOCS)-3 and the C-X-C chemokines CXCL1 and CXCL2 promote tumor aggressiveness and radiation resistance in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A10.
Abstract A14: Canonical WNT/β-catenin pathway activation suppresses embryonal rhabdomyosarcoma growth and self-renewal
Authors: Chen Eleanor , DeRan Michael , Grandinetti Katherine Brooke , Ignatius Myron , Clagg Ryan , McCarthy Karin , Lobbardi Riadh , Wu Xu , Langenau David
Published: May 2015

Embryonal rhabdomyosarcoma (ERMS) is a common pediatric malignancy of muscle with relapse being the major clinical challenge. Self-renewing tumor-propagating cells (TPCs) drive cancer relapse and are confined to a molecularly definable subset of ERMS cells. To identify drugs that suppress TPC function, a large-scale chemical screen comprising of ~40,000 compounds including 47% FDA-approved drugs was completed, identifying GSK3-inhibitors as potent suppressors of ERMS growth through inducing terminal differentiation of TPCs into myosin-expressing cells. In support of GSK3 inhibitors functioning through activation of the canonical WNT pathway, recombinant WNT3A and a stabilized β-catenin enhanced differentiation and reduced self-renewal in human ERMS cell lines. Moreover, treatment of tumor-bearing zebrafish with a GSK3 inhibitor activated the WNT/β-catenin pathway, resulting in suppressed ERMS growth, depleted TPCs, and diminished self-renewal capacity in vivo. As canonical WNT signaling is essential for transition from muscle stem cell proliferation to myogenic differentiation during regeneration, our findings suggest that the same developmental pathways that regulate muscle stem cell self-renewal also contribute to tumorigenesis in ERMS. GSK3 inhibitors are being assessed for their efficacy in inhibiting growth as well as inducing differentiation of human ERMS in xenograft mouse models. Our work has identified the vital role of canonical WNT pathway in regulating differentiation and self-renewal of ERMS and demonstrated the effective application of small molecule inhibitors to target differentiation of TPCs in ERMS.

Citation Format: Eleanor Chen, Michael DeRan, Katherine Brooke Grandinetti, Myron Ignatius, Ryan Clagg, Karin McCarthy, Riadh Lobbardi, Xu Wu, David Langenau. Canonical WNT/β-catenin pathway activation suppresses embryonal rhabdomyosarcoma growth and self-renewal. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A14.
Abstract A19: Progesterone receptor signaling inhibits cervical cancer
Authors: Mehta Fabiola , Yoo Young A , Son Jieun , DeMayo Francesco J. , Lydon John P. , Chung Sang-Hyuk
Published: May 2015

Human papillomavirus (HPV) is the major etiological factor for cervical cancer, which remains third most frequent and fourth most deadly malignancy in women worldwide. However, evidence indicates that other non-viral cofactors are also required for the disease. The uterine cervix is sensitive to female hormones, which have been implicated in cervical carcinogenesis. A transgenic mouse model expressing HPV oncogenes E6 and/or E7 is relevant to human cancer. We use this model to study a mechanism of hormone actions in the context of this common malignancy. Estrogen and estrogen receptor α (ERα) are required for the development of cervical cancer in this mouse model. ERα is known to upregulate expression of the progesterone receptor (PR), which, upon activation by its ligands, either promotes or inhibits carcinogenesis depending on the tissue context. In the present study, we demonstrate that progesterone-PR signaling inhibits cervical and vaginal epithelial cell proliferation in a ligand-dependent manner. We also demonstrate that synthetic progestin medroxyprogesterone acetate (MPA) promotes regression of cancers and precancerous lesions in the female lower reproductive tracts (i.e., cervix and vagina). Our results provide the first experimental evidence supporting that the progesterone signaling is inhibitory for cervical cancer in vivo. Our results also suggest that cervical cancer recurs if MPA treatment is ceased. They imply that MPA efficiently get rid of bulk of disease, yet cancer progenitor/stem cells remain. Our mouse model provides a unique opportunity to interrogate mechanism of PR and PR ligands in cervical cancer.

Citation Format: Fabiola Mehta, Young A Yoo, Jieun Son, Francesco J. DeMayo, John P. Lydon, Sang-Hyuk Chung. Progesterone receptor signaling inhibits cervical cancer. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A19.
Abstract A29: Interrogating therapeutic response for advanced prostate cancer in vivo using cross-species regulatory models
Authors: Mitrofanova Antonina , Floch Nicolas , Aytes Alvaro , Shen Michael , Abate-Shen Cory , Califano Andrea
Published: May 2015

While most men diagnosed with localized prostate cancer now have favorable outcomes, those with advanced disease often undergo androgen deprivation therapy, which initially leads to tumor regression but ultimately results in the emergence of a castration-resistant form of the disease that is highly metastatic and ultimately fatal. Our research is focused on generating mouse models of advanced prostate cancer to evaluate new therapeutic approaches for its treatment. Toward this end, we have generated state-of the-art genetically-engineered mouse (GEM) models, which are based on biologically-relevant signaling pathways and recapitulate prostate cancer from its earliest to most advanced stages. Indeed these mice recapitulate lethal prostate cancer as they display distant metastases with 100% penetrance as well as disseminated cells in the bone marrow. By pursuing preclinical studies in these GEM mice we have found that combinational targeted of key signaling pathways is significantly more effective than standard of care (i.e., chemotherapy) for blocking cancer progression, improving survival and inhibiting metastases in vivo.

However, one of the main obstacles for effectively translating results from preclinical studies in genetically-engineered mouse models is difficulties in overcoming inherent species differences that may preclude direct comparisons from mice to man. To overcome this limitation, we have assembled regulatory networks (called interactomes) for both mouse and human prostate cancer to enable cross-species analyses for identification of master regulators (driver genes) that underlie the therapeutic response. In particular, using these computational resources we have interrogated gene expression profiles from preclinical studies in our genetically-engineered mice, and have identified molecular regulators that predict therapeutic response in the mice and are conserved in human prostate cancer. Our approach highlights the value of cross-species analyses of preclinical studies in mice and human clinical data for predicting drug response.

Citation Format: Antonina Mitrofanova, Nicolas Floch, Alvaro Aytes, Michael Shen, Cory Abate-Shen, Andrea Califano. Interrogating therapeutic response for advanced prostate cancer in vivo using cross-species regulatory models. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A29.
Abstract A37: Role of autophagy inhibition in metastatic disease utilizing mouse models
Authors: Barnard Rebecca , Hansen Ryan J. , Maycotte Paola , Thorburn Andrew , Gustafson Daniel L.
Published: May 2015

Modification of autophagy to enhance cancer treatment is being aggressively pursued in the laboratory and clinic; however, it remains to be seen if inhibition or induction of autophagy is going to result in better outcomes. In addition, the advantages of autophagic modification with neoadjuvant chemotherapy vs. surgical adjuvant chemotherapy have yet to be reported. The 4T1-luc metastatic mammary mouse cell line modified to express luciferase was used to induce lung metastases, both from orthotopic growth of primary tumors or experimentally induced via tail vein injection. Both pharmacologic inhibition (chloroquine (CQ) administered 60 mg/kg daily to mice) and genetic knockdown of a key protein necessary for autophagy alone (4T1-luc-shBeclin-1 cells) did not alter time to metastasis (as determined by luciferase positive lungs) when 4T1-luc cells were injected via tail vein. In addition, inhibiting autophagy in 4T1-luc cells with CQ in vitro prior to injection via the tail did not alter time to metastasis. Similar results were observed with pharmacologic inhibition on experimentally induce lung metastases using the metastatic mouse melanoma B16-F10 cell line. In vitro work, by us and others, has lead us to conclude that pharmacologic inhibition plus cisplatin leads to greater growth inhibition and cell kill in vitro than either alone. Effect of autophagy inhibition in combination with cisplatin on metastatic formation in a neoadjuvant setting was tested by treating mice with daily with CQ and cisplatin (q14d) one day post tumor cell injection in the mammary fat pad. Additional experiments were conducted to determine if autophagy inhibition plus cisplatin in a surgical adjuvant setting delays metastasis formation. In each instance, primary tumors were removed at ~100mm3 and mice were followed until luciferase positive lungs were observed. From these results we conclude that autophagy inhibition, using CQ, does not alter metastatic growth alone and appears to slightly enhance the efficacy of cisplatin on treating metastases. It remains to be seen if autophagy inhibition with other compounds would alter results.

Citation Format: Rebecca Barnard, Ryan J. Hansen, Paola Maycotte, Andrew Thorburn, Daniel L. Gustafson. Role of autophagy inhibition in metastatic disease utilizing mouse models. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A37.
Abstract A41: Patient-Derived Fluorescent Orthotopic Xenografts (PDOX™) models for personalized anti-metastatic cancer therapy and drug discovery
Authors: Hoffman Robert M.
Published: May 2015

The original patient-derived xenografts (PDX) was developed in Rygaard's laboratory (Acta Pathol Microbiol Scand 77: 758-760, 1969), who was the first to use nude mice for cancer research, in this case implanting human patient tumors subcutaneously. A number of other laboratories around the world followed with their own subcutaneous nude mouse models of patient tumors as well as cancer cell lines in nude mice. Two decades ago, our laboratory developed the first orthotopic patient tumor models in nude mice for colon cancer (Proc Natl Acad Sci USA 88: 9345-9349, 1991), pancreatic cancer (Proc Natl Acad Sci USA 89: 5645-5649, 1992), for ovarian cancer (Anticancer Research 13, 283-286, 1993) and for breast cancer (Anticancer Res. 13, 901 904, 1993). These were major advancements since this was the first time metastasis could occur in PDX since the patent tumors were implanted orthotopically. We have termed these models patient-derived orthotopic xenografts (PDOX™). We have now developed technology to make the orthotopic patient tumor models genetically fluorescent by passaging patient tumors through transgenic mice ubiquitously expressing fluorescent proteins (J Cell Biol 113, 2290-2295, 2012) in order to label the PDOX™ stroma. The labeled stroma is stable upon passage to non-transgenic mice for rapid screening of effective agents. PDOX™, enable rapid screening of anti-metastatic agents for patients with highly recalcitrant tumors, a major advance in individualized cancer therapy.

Citation Format: Robert M. Hoffman. Patient-Derived Fluorescent Orthotopic Xenografts (PDOX™) models for personalized anti-metastatic cancer therapy and drug discovery. [abstract]. In: Proceedings of the AACR Special Conference: The Translational Impact of Model Organisms in Cancer; Nov 5-8, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(11 Suppl):Abstract nr A41.