bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract B022: cDNA microarray analysis of genes associated with reduced annexin A6 expression in invasive breast cancer cells
Authors: Sakwe Amos M. 
Published: May 2015

Abstract
Recent studies have shown that the calcium-dependent membrane binding protein, annexin A6 (AnxA6) is involved in cell proliferation, membrane dynamics, calcium fluxes across the plasma membranes and cell-cell and cell extracellular matrix interactions and cell motility. Together with our recent observation that AnxA6 is down regulated in breast cancer, this suggests that AnxA6 may influence the expression of a very diverse set of genes. We therefore, investigated changes in gene expression profiles associated with AnxA6 depletion in invasive breast cancer cells. To do this we generated AnxA6 depleted BT-549 cells with varying extents of AnxA6 down regulation. Two of the cell lines designated BT-A6sh2 and BT-A6sh5 as well as pGIPZ transfected control cells were used in the cDNA microarray analysis. Analysis of the microarrays revealed that a total of 558 genes were significantly down-regulated of which 38 were down regulated by at least 2.0-fold and p &lt; 0.05. Meanwhile, 625 genes were significantly up-regulated and 33 were up regulated by at least 2.0-fold and p &lt; 0.05. Interestingly, the greater the extent of AnxA6 depletion the greater the number of genes that were up or down regulated. Among the up regulated genes were RASGRF2, CDH2, JAG1, PCDH10 and PCDH7. Among the down regulated genes were FNDC1, CD24 SLC4A4, CALB2, CSPG4 and ST8SIA6. Interestingly, LGALS3 and CDH3 were among several other genes that were up regulated while EGFR, a predictive marker of basal-like breast cancer, was among the genes that were down regulated following &gt;80% depletion of AnxA6. Validation of some of these genes by quantitative RT-PCR suggests that AnxA6 influences Ras signaling, cadherin-mediated cell-cell interactions, solute transport, cell-extracellular matrix interactions, calcium signaling and more interestingly, cancer stem cell phenotypes. Down-regulation of CD24 and up-regulation of N- and P-cadherin suggest that reduced AnxA6 expression as previously shown in breast cancer tissues also facilitates the transformation of tumor cells into CD24-low mesenchymal stem cell-like phenotypes. These data suggest that reduced AnxA6 expression in invasive breast cancer is accompanied by modulation of a wide range of genes that influence several aspects of breast cancer progression, some of which are potentially useful targets for prognosis and therapeutic intervention.
Citation Format: Amos M. Sakwe. cDNA microarray analysis of genes associated with reduced annexin A6 expression in invasive 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 B022.
Abstract B047: Cyclin-dependent kinase 2 regulates androgen receptor activity in estrogen receptor negative breast cancer
Authors: Proctor Luke A. , Hanson Adrienne R. , Butler Miriam S. , Tilley Wayne D. , Moore Nicole L. 
Published: May 2015

Abstract
There are limited treatment options for estrogen receptor (ER)-negative breast cancer, a disease subtype that is highly aggressive and associated with poor clinical outcome. The androgen receptor (AR) is expressed in approximately 30% of ER-negative breast cancers and is emerging as a viable therapeutic target. AR activity is influenced by numerous intracellular signalling pathways which post-translationally modify the AR protein to finely regulate its stability and transcriptional output. This study is investigating the functional interaction between cyclin dependent kinases (CDKs) and AR in breast cancer. We hypothesize that CDK2 is required for optimal AR activity and androgen-regulated cell growth in ER-negative breast cancer cells and that inhibition of CDK2 may be an effective approach to reduce ER-negative breast cancer cell growth. AR-positive, ER-negative MDA-MB-453 breast cancer cells were treated with the androgen 5α-dihydrotestosterone (DHT) in the presence or absence of the CDK2 inhibitors roscovitine, NU6102 or CVT-313. The effects on AR target genes as well as total and phosphorylated AR were assessed by quantitative RT-PCR and Western blotting while MTT assay, trypan blue dye exclusion and flow cytometry were used to examine cell proliferation and viability. DHT induced expression of the AR target genes FKBP5, c1ORF116, SEC14L2 and RANBP3L however each of the CDK2 inhibitors completely blocked the stimulatory effect of DHT on these genes. The CDK2 inhibitors also reduced the ability of DHT to stabilize AR protein and induce Ser81-AR phosphorylation. Basal and DHT-induced cell proliferation was blocked by the CDK2 inhibitors, and this was associated with cell cycle arrest and cell death. The results suggest that AR requires CDK2 for optimal transcriptional activity and proliferative effects in breast cancer cells. This may have important therapeutic implications for ER-negative, AR-positive breast cancers.
Citation Format: Luke A. Proctor, Adrienne R. Hanson, Miriam S. Butler, Wayne D. Tilley, Nicole L. Moore. Cyclin-dependent kinase 2 regulates androgen receptor activity in estrogen receptor 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 B047.
Abstract B095: CARM1 methylates BAF155 and perturbs chromatin remodeling machinery to enhance tumor progression
Authors: Wang Lu 
Published: May 2015

Abstract
CARM1 belongs to the type I protein arginine (R) methyltransferase (PRMT) family and asymmetrically di-methylates proteins on arginines. Because CARM1 is highly expressed in high grade breast tumors and was shown to transactivate cancer-relevant transcription factors including ERa, NF-kb, p53 and E2F1, it has been strongly implicated in tumorigenesis. To fully characterize functions of CARM1 in breast cancer, we knocked-out CARM1 from several breast cancer cell lines using Zinc-Finger Nuclease technology. Western blot using an asymmetric di-methylated R antibody revealed striking differences between CARM1 KO and parental MCF7 cell lysates, indicating that CARM1 methylates a significant number of substrates in breast cancer cells. BAF155, a core subunit of SWI/SNF chromatin remodeling complex, was identified as a CARM1 substrate by mass spectrometry. Further biochemical analyses validated that BAF155 was methylated by CARM1 in vivo and in vitro and methylation was mapped to a single site, R1064. We next generated BAF155R1064K knock-in MCF7 and MDA-mb-231 cells and showed that methylation of BAF155 is essential for breast cancer cell growth, colony formation and migration. Further, we developed an antibody that selectively recognized methylated form of BAF155 (me-BAF155) and observed strong nuclear me-BAF155 staining in invasive ductal carcinoma but not in the normal breast tissue. Importantly, me-BAF155 immunostaining positively correlates with tumor stage and metastasis. To understand the molecular mechanism by which BAF155 methylation affects tumorigenesis, we performed ChIP-seq using ChIP-validated BAF155 antibody in the BAF155WT or BAF155R1064K knock-in MCF7 cells. Interestingly, C-Myc pathway genes were only identified in WT but not mutant BAF155 regulated categories. Individual ChIP assays validated differential binding of BAF155WT or BAF155R1064K to specific target genes and importantly, the mRNA levels of these genes were affected correspondingly. This result suggests that BAF155 methylation affects gene expression by altering genomic association of BAF155, and perhaps the SWI/SNF complex, to chromatin regions. Collectively, our study revealed novel mechanisms by which CARM1 perturbs the chromatin remodeling machinery to enhance tumor progression.
Citation Format: Lu Wang. CARM1 methylates BAF155 and perturbs chromatin remodeling machinery to enhance tumor 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 B095.
Abstract B098: Tumor cell-derived IL-4 suppresses tumor growth and metastasis
Authors: Zhang Connie Shengnan , Greer Peter A. 
Published: May 2015

Abstract
Interleukin 4 (IL-4) is a cytokine that, among other actions, can induce macrophages to undergo alternative activation and polarize to M2 macrophages which have been reported to promote tumorigenesis and metastasis. IL-4 also promotes the formation of multinucleated giant cells from macrophages in vitro and participates in the development of the foreign body reaction in vivo.
AC2M2 cells, a highly metastatic mouse carcinoma cell line, were transduced with retroviruses expressing IL-4 (IL-4-AC2M2) or empty vector control (EV-AC2M2). Co-culture experiments showed that AC2M2-derived IL-4 polarized macrophages to express the M2 marker, arginase 1. EV- and IL-4-AC2M2 cells grew at the same rate in vitro. However, mice injected with IL-4-AC2M2 cells grew tumors at a significantly reduced rate as compared to control mice injected with EV-AC2M2 cells in an orthotopic mouse mammary tumor engraftment model. IL-4 expression also correlated with elimination of lung metastasis. Reduced primary tumor growth and complete abolishment of lung metastasis in the IL-4 group correlated with a 30-fold increase of tumor associated macrophage populations and macrophage phagocytosis of tumor cells.
Thus, tumor-derived IL-4 suppressed tumorigenesis and lung metastasis by activating macrophage phagocytosis in the tumor microenvironment; suggesting that IL-4 could be a good candidate for immunotherapy.
Note:This abstract was not presented at the conference.
Citation Format: Connie Shengnan Zhang, Peter A. Greer. Tumor cell-derived IL-4 suppresses tumor growth and metastasis. [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 B098.
Abstract IA02: Tumor plasticity and reactive stroma in breast cancer metastasis
Authors: Kang Yibin 
Published: May 2015

Abstract
Metastasis represents the most devastating stage of cancer progression. The multi-step cascade of cancer metastasis is driven by both intrinsic changes of cancer cell properties, as well as the stromal reaction to tumor cells. Epithelial-mesenchymal transition (EMT) is a complex process that is associated with dramatic changes in cell adhesion, polarity, and migratory properties, and is intimately associated both with cell fate transitions during embryonic development and with the acquisition of invasive properties during early steps of cancer metastasis. We found that the transcription factor Elf5, a key regulator of alveologenesis in the mammary gland, regulates EMT in both mammary gland development and metastasis. This specific role for Elf5 in suppressing EMT and metastasis was uncovered via analyses of Elf5 conditional knockout animals, various in vitro and in vivo models of EMT and metastasis, an MMTV-neu transgenic model of mammary gland tumor progression, and clinical breast cancer samples. Furthermore, we demonstrate that this role of Elf5 is mediated by the direct transcriptional repression of Snail2/Slug, a master regulator of mammary stem cells and a known inducer of EMT. These findings establish a broad molecular function of Elf5 that extends from being a key cell lineage regulator during normal mammary gland development to serving as a suppressor of EMT and metastasis in breast cancer.
The growth of disseminated tumor cells at distant organs represents a critical final stage of metastasis development. Bone metastasis is a frequent occurrence in breast cancer, affecting more than 70% of late stage cancer patients. Increasing evidence suggest that the development of bone metastasis relies on the positive feedbacks from stromal components of the bone microenvironment. Using in vivo imaging technology, we showed that TGFβ is released from bone matrix upon bone destruction, and signals to breast cancer to further enhance their malignancy in developing bone metastasis. We furthered identified Jagged1 as a TGFβ target genes in tumor cells that engaged bone stromal cells through the activation of Notch signaling to provide a positive feedback to promote tumor growth and to activate osteoclast differentiation. More recently, we identified osteoclast-derived miRNAs as biomarkers and therapeutic targets of osteolytic bone metastasis. Importantly, pharmaceutical inhibitors against TGFβ and Notch signaling pathways and miRNAs blocking osteoclast differentiation significantly reduce the development of bone metastasis, suggesting novel avenues for clinical management of skeletal complications of breast cancer.
Citation Format: Yibin Kang. Tumor plasticity and reactive stroma in breast cancer metastasis. [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 IA02.
Abstract IA11: Dissecting cancer through the lens of development
Authors: Wahl Geoffrey Myles , Dravis Christopher , Johns Claire , Rodewald Rose , Spike Benjamin T. , Trejo Christy 
Published: May 2015

Abstract
Mammary stem cells (MaSCs) self-renew and generate the different epithelial cell types of the breast. Impressively, a single MaSC can regenerate an entire functional mouse mammary gland when transplanted into a cleared fat pad. Intriguingly, stem-like cells have been identified in some types of breast cancer using bioinformatic strategies. These observations raise a number of important questions: Do some breast cancers arise by mutations occurring in mammary stem cells, as such cells have a high capacity for self-renewal, proliferation and differentiation? Or, do breast cancers arise by de-differentiation of cells to a stem-like state, as such cells may be particularly able to generate the heterogeneity that fuels tumor progression? If stem cells contribute to cancer, what is the nature of such cells, and can we use this information to devise better treatment strategies or prognostic molecular signatures? Finally, cancer cells that seem particularly competent at generating tumors upon xenografting into nude mice have also been suggested to exhibit stem cell characteristics such as multi-lineage differentiation and self-renewal. Are these “cancer stem cells” mutant stem cells, or a different type of cell that is particularly tumorigenic in the xenograft assay? Here, we integrate approaches involving developmental, stem cell, and cancer biology to gain insight into these challenging questions.
We took a new direction to isolate and characterize MaSCs during fetal mammogenesis when undifferentiated cells are expected to be enriched. We microdissected and dissociated fetal mammary cells across different stages of development and conducted limiting dilution, orthotopic mammary transplantation analyses to determine fetal MaSC (fMaSC) frequency. We found that the fMaSCs are not measurable until mid-gestation, when an elongating duct that invades through the adjacent mesenchyme is formed. We used flow sorting to significantly enrich fMaSCs, and then used microarray and single cell RNA-seq to begin to interrogate the molecular pathways that drive their proliferation. We find that the pathways they express, and that are expressed by the fetal stroma that surround them, are enriched in several very aggressive types of human breast cancer, as well as in several genetically engineered mouse models. These data and powerful experimental strategies are opening new ways of understanding cancer from a developmental perspective, and for using this knowledge to develop new diagnostic and treatment strategies.
Citation Format: Geoffrey Myles Wahl, Christopher Dravis, Claire Johns, Rose Rodewald, Benjamin T. Spike, Christy Trejo. Dissecting cancer through the lens of development. [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 IA11.
Abstract IA23: Molecular and clinical impact of APOBEC3B mutagenesis in breast cancer
Authors: Harris Reuben S. 
Published: May 2015

Abstract
Recent studies have revealed a role for the DNA cytosine deaminase APOBEC3B in breast cancer mutagenesis. First, APOBEC3B mRNA is up-regulated in the majority of primary breast tumors and breast cancer cell lines. Second, endogenous APOBEC3B protein is predominantly nuclear and the only detectable source of DNA C-to-U editing activity in breast cancer cell line extracts. Third, APOBEC3B knockdown causes a corresponding decrease in genomic uracil concentrations, mutation frequencies, and C-to-T mutation levels in breast cancer cell lines. Fourth, the biochemical signature of APOBEC3B is evident in breast cancer mutation spectra. Fifth, breast carcinomas that express high levels of APOBEC3B have twice as many mutations as those expressing low levels. Finally, high levels of APOBEC3B associate with poorer prognostic outcomes including shorter survival durations. All of these data are consistent with a model in which APOBEC3B-catalyzed DNA cytosine deamination provides a chronic source of DNA damage and mutagenesis in breast carcinomas that helps to explain how some tumors evolve rapidly and manifest gross heterogeneity.
Citation Format: Reuben S. Harris. Molecular and clinical impact of APOBEC3B mutagenesis 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 IA23.
Abstract A34: Mammary-specific, doxycycline-regulated transposon mobilization for identifying driver genes in mouse models of breast cancer
Authors: Gestl Shelley A. , Gunther Edward J. 
Published: May 2015

Abstract
Transposon-mediated mutagenesis offers a powerful tool for discovering genetic changes that contribute to cancer pathogenesis. Tissue-specific transposon mobilization has been exploited widely to identify candidate cancer genes in a variety of tissues, including intestine, pancreas, and liver. These models typically use tissue-specific expression of the Cre recombinase to activate a latent transposase allele, which in turn mobilizes a mutagenic transposon. Notably, transposase expression cannot be halted once activated in these models, potentially leading to unwanted transposition events that either delete driver insertions or create additional passenger insertions. As an alternative strategy, we generated transgenic mice harboring the SB11 transposase under the control of tet operator sequences. Tet-O-SB11 founder lines were characterized that permit a range of transgene expression levels when crossed to mice carrying a mammary-specific transactivator, MMTV-rtTA. We show that efficient mobilization of the T2/Onc transposon in mammary tissue requires high-level SB11 expression, which strictly depends on doxycycline administration in our models. Furthermore, efficient T2/Onc mobilization enabled by high-level SB11 expression strongly cooperated with Wnt1 transgene expression to drive mammary tumorigenesis in vivo. Preliminary analysis of transposon integration sites in these mammary tumors confirms that transposon-mediated mutations serve as pathogenic driver events. Temporal regulation of transposase-mediated mutagenesis may offer a flexible tool for discovering driver events operative at various stages of tumor progression.
Citation Format: Shelley A. Gestl, Edward J. Gunther. Mammary-specific, doxycycline-regulated transposon mobilization for identifying driver genes in mouse models of breast 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 A34.
Abstract B24: ATDC (Trim29) drives invasive bladder cancer formation
Authors: Palmbos Phillip , Wang Lidong , Yang Huibin , LeFlein Jake , Wilkinson John E. , Kumar-Sinha Chandan , Kunju L. Priya , Daignault Stephanie , Wu Xue-Ru , Lotan Yair , Liebert Monica , Ljungman Mats , Simeone Diane 
Published: May 2015

Abstract
Bladder cancer is a common and deadly malignancy, but incomplete understanding of the molecular events driving tumor development and metastasis has limited development of effective treatments. Ataxia-Telangiectasia Group D Complementing (ATDC; also named TRIM29) is highly expressed in many cancer types, including bladder and pancreas. To determine the role of ATDC in tumorigenesis, we developed a novel transgenic mouse model in which ATDC was overexpressed in multiple tissue types. The dominant phenotype in these mice was the development of both papillary and invasive bladder carcinoma beginning at approximately 8 months of age. In this model, invasive bladder tumors were histologically indistinguishable and shared a similar gene expression signature with human invasive bladder cancers. We also found that ATDC was highly expressed in ~70% human bladder cancers where it marked invasive tumors and correlated with worse survival after chemotherapy (p = 0.002). Furthermore, ATDC knockdown decreased proliferation, invasion and tumor growth in multiple human bladder cancer cell lines and in an in vivo orthotopic bladder tumor model. ATDC-induced bladder tumorigenesis was mediated by upregulation of DNA methyltransferase 3A (DNMT3A), which drove PTEN promoter methylation and silencing, events which promoted invasion and proliferation in both transgenic mice and human bladder cancers. These findings establish ATDC as a novel driver and therapeutic target in bladder cancer. In addition, the ATDC transgenic mouse model should serve as an important and unique new model to study bladder cancer development, progression and therapeutic responses.
Citation Format: Phillip Palmbos, Lidong Wang, Huibin Yang, Jake LeFlein, John E. Wilkinson, Chandan Kumar-Sinha, L. Priya Kunju, Stephanie Daignault, Xue-Ru Wu, Yair Lotan, Monica Liebert, Mats Ljungman, Diane Simeone. ATDC (Trim29) drives invasive bladder cancer formation. [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 B24.