bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2289: Potential role for Src kinase inhibitors in PKCα-overexpressing breast cancer
Authors: Molloy Mary E. , Tonetti Debra A. 
Published: June 2012

Abstract
The purpose of this study was to evaluate the role of Src kinase in estrogen induced growth inhibition in the T47D/PKCα breast cancer cell line. Our lab has previously shown that constitutive overexpression of protein kinase Cα (PKCα) imparts a tamoxifen-resistant, hormone-independent phenotype in the T47D:A18 breast cancer cell line (Chisamore, et al. Clin Cancer Res 2001; 7(10):3156-65). Furthermore 17β-estradiol (E2) inhibits tumor growth in vivo as well as inhibits colony formation when cells are grown in 3D Matrigel (Zhang, et al. Mol Cancer Res 2009; 7(4):498-510). Here we show that the Src kinase inhibitor PP2 (5 μM) significantly inhibited T47D/PKCα colony formation in 3D Matrigel, but was unable to inhibit proliferation in vitro. The combination of PP2 and E2 treatment in 3D Matrigel did not further decrease colony number when compared to either alone. This suggests that these compounds may be acting on the same pathway and that E2 may be inhibiting Src kinase activity. To examine the effect of E2 on Src in T47D/PKCα xenograft tumors we probed the phosphorylation state of Src on Tyr416, known to be necessary for its full kinase activity. Src is basally phosphorylated on Tyr416 in T47D/PKCα cells. Interestingly, E2 treatment in vivo resulted in a decrease in phospho-Src. Erk 1/2, a downstream target of Src, is basally phosphorylated in T47D/PKCα cells. E2 treatment also resulted in a decrease in phospho-Erk1/2, in accordance with decreased Src phosphorylation. A reduction in phosphorylated Src and Erk1/2 was not seen in vitro indicating that the extracellular matrix is necessary for E2 to elicit an inhibitory effect on these proteins. In this study, we report that E2 treatment in vivo inhibited Src phosphorylation in tamoxifen resisitant T47D/PKCα tumors. Additionally pharmacological inhibition of Src inhibited T47D/PKCα colony formation in 3D Matrigel. Taken together, our results suggest that a Src inhibitor may be a potential therapeutic option for patients with PKCα-overexpressing breast cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2289. doi:10.1158/1538-7445.AM2011-2289
Abstract 2294: The nuclear association among ERα – PR – AIB1 is modulated by progestins and antiprogestins in experimental breast cancer
Authors: Giulianelli Sebastian J. , Gorostiaga María A. , Lanari Claudia 
Published: June 2012

Abstract
The nuclear receptor coactivator AIB1 (SRC-3) is intimately associated with hormone action in estrogen receptor (ER)-positive breast cancer, and its overexpression has been associated with early resistance to endocrine therapy. In two models of ER+, progesterone receptor (PR)+ breast cancer, human T47D cells growing in vitro and C4-HD and C4-HI mouse mammary carcinomas maintained by syngeneic transplantations in BALB/c mice, we have shown that progestins induce a nuclear physical association between ERα and PR isoform A (PRA). We hypothesize that this interaction is necessary to induce progestin-induced cell proliferation. While both the pure antiestrogen ICI 182780 (ICI) and the antiprogestin RU486 inhibit tumor growth, only ICI blocked the ERα-PRA nuclear interaction induced by medroxyprogesterone acetate (MPA). RU486 showed an agonist-like effect stimulating the association between both receptors. The aim of this study was to investigate the interaction of ERα with PR isoform B (PRB) in both models and to evaluate the role of AIB1 in progestin-induced proliferation and in RU486-induced inhibition of cell proliferation. MPA (10nM) treatment induced an early increase in the nuclear co-localization between pSer118 ERα and pSer162 PRB in epithelial cells from the mouse model (p&lt;0.001), and between total ERα with pSer162 PRB in T47D cells (p&lt;0.001), as shown by confocal microscopy. By co-immunoprecipitation assays we corroborated that both PR isoforms interact with ERα in the cell nuclei. We also found that MPA increased the nuclear association of pSer294 PR and ERα with AIB1 in the murine epithelial tumor cells (p&lt;0.001). These results were corroborated by co-immunoprecipitation in nuclear extracts from untreated or MPA-treated T47D cells. RU486 (10nM) induced similar ERα-PR interactions as MPA, but no association between PR and AIB1 was observed in RU486-treated cells. Our data support the hypothesis that a nuclear complex of ERα, both PR isoforms, and AIB1 mediates the proliferative effects of MPA. In addition, the results suggest that the lack of association of ERα-PR complexes with AIB1 may explain the antagonist effect of RU486 in these cells, supporting the hypothesis that the inhibitory effects of RU486 are related to genomic events.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2294. doi:10.1158/1538-7445.AM2011-2294
Abstract 2311: A novel kinase inhibitor of FADD phosphorylation chemosensitizes through the inhibition of NF-κB
Authors: Schinske Katrina , Nyati Shyam , Williams Terence , Johnson Timothy , Ross Brian , Tomás Ricardo Pérez , Rehemtulla Alnawaz 
Published: June 2012

Abstract
Fas-Associated protein with Death Domain (FADD) was originally reported as a pro-apoptotic adaptor molecule that mediates receptor induced apoptosis. Recent studies have revealed a potential role of FADD in NF-κB activation, embryogenesis, and cell cycle regulation and proliferation. Over-expression of FADD and its phosphorylation have been associated with the transformed phenotype in many cancers and is therefore a potential target for therapeutic intervention. In an effort to identify novel chemical entities that inhibit FADD phosphorylation, we screened an NCI diversity compound collection using a cell based assay recently developed in our laboratory for the detection of FADD-kinase activity (Khan, 2010). The screen resulted in the identification of NSC 47147 as a potent inhibitor of FADD phosphorylation. This compound was shown to be an inhibitor of CKIα, a previously described FADD kinase, with an IC50 = 1.5 µM. We demonstrate that inhibition of FADD phosphorylation by NSC 47147 results in a decrease in NF-κB activity, thereby potentially sensitizing tumor cells to chemotherapy. In support of this, treatment of lung cancer cells with NSC 47147 and cisplatin in culture as well as in a mouse xenograft model resulted in the synergistic induction of apoptosis and enhanced tumor control compared to either agent alone. These results provide evidence for the inhibition of FADD phosphorylation as a viable target for anti-cancer therapy.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2311. doi:10.1158/1538-7445.AM2011-2311
Abstract 2312: Using multidimensional real-time cell profiling approach to identify novel inhibitors of key targets and pathways involved in cancer maintenance and progression
Authors: Ke Ning , Wang Xiaobo , Xu Xiao , Abassi Yama 
Published: June 2012

Abstract
A high throughput cell-based phenotypic screening method was developed using real time cell analysis system which is based on impedance sensor technology. Using compounds with known mechanisms, we had previously demonstrated small molecule compounds produce characteristic time-dependent cell response profiles (TCRP) which could be indicative of mechanism of action. The cellular-basis for the anti-mitotic TCRP has been extensively validated using both anti-mitotic compounds and siRNAs targeting mitotic machineries (e.g. Eg5, PLK1 & Mad2). In this study, we used the TCRP approach to screen a 119,595 compound library for novel anti-cancer agents. The screening was performed at a final concentration of 17.8 µM using a human non small cell lung cancer line, H1993. The TCRP was monitored for 48 hours after compound treatment and the data generated was analyzed using in-house developed software to perform clustering analysis. For each screening set, a panel of compounds with known mechanisms of action were used as positive control and also served as reference for TCRP-based clustering to predict mechanisms of action. After multi-dose confirmation, 239 hits with IC50 values less than 8.9 µM were subjected to TCRP analysis. In comparison with reference TCRP patterns, we indentified 26 hits corresponding to tyrosine kinase inhibitors, 9 hits as DNA damaging agents, 125 hits as anti-mitotic agents, and 28 hits as cytostatic agents. Detailed characterization of 117 putative anti-mitotic compounds with traditional p-H3 based methods demonstrates 113 of them (96.6%) mediated mitotic arrest, thus demonstrating the robust predictive nature of the approach. We also have validated the putative tyrosine kinase inhibitors in in vitro kinase assays. TCRP-based phenotypic screening displays a novel drug screening approach with great potentials for discovering new pathway-modulating anticancer agents.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2312. doi:10.1158/1538-7445.AM2011-2312
Abstract 2313: DDR1 receptor kinase pathway as an emerging target in cancer therapeutics
Authors: Kim Hyung-Gu , Mandinova Anna , Hwang So Young , Schreiber Stuart L. , Lee Sam W. 
Published: June 2012

Abstract
We have identified a novel p53 pro-survival signaling pathway involving up-regulation/activation of a p53 target gene DDR1 and its down-stream signaling, which can influence the balance between cell death and survival in a p53 dependent response. Unlike other p53 target genes that function as either cell cycle inhibitors or apoptosis-promoters, DDR1 kinase promotes cell survival by counteracting p53-mediated cell death/apoptosis. Furthermore, accumulating evidence suggest that aberrant signaling through DDR1 kinase is closely associated with various steps of tumorigenesis and carcinogenesis, although little is known about the molecular mechanism(s) underlying the role of DDR1 in cancer. We have identified TK0019 as a DDR1 tyrosine kinase inhibitor via the target-based small molecule array screening. TK0019 specifically targets DDR1 kinase and its novel targets involved in EMT (Epithelial-Mesenchymal transition) pathway such as Slug, AKT and vimentin, which is known to play a major role in tumor progression and metastasis development. In addition, TK0019 suppressed the activation of AKT prosurvival protein and of essential EMT pathway proteins involved in tumor migration/invasion. DDR1 kinase is highly expressed in a variety of human cancer and occasionally mutated in lung cancer and leukemia. TK0019 binds directly to N-terminal part (extracellular region of the receptor) of DDR1 protein and specifically inhibits DDR1 kinase activation in response to its ligand. TK0019 demonstrated antiproliferative activity against a range of DDR1-overexpressing cancer cell lines without high cytotoxicity in normal cells. TK0019 also exhibited the potent anti-growth properties even in EGFR targeted (erlotinib and gefitinib) drug-resistant cancer cells. TK0019 potently inhibited spontaneous formed breast cancer tumors and their associated metastasis in mice with no apparent adverse effects on normal organs. More particularly, the invention features a novel use of TK0019 for effective treatment of the variety human cancers by inhibiting tumor migration/invasion via the inactivation of EMT pathway.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2313. doi:10.1158/1538-7445.AM2011-2313
Abstract 2323: Molecular modeling studies of the STAT3 homodimer:DNA complex
Authors: Husby Jarmila , Haider Shozeb M. , Zinzella Giovanna , Thurston David E. , Neidle Stephen 
Published: June 2012

Abstract
Signal Transducers and Activators of Transcription (STAT) are a group of latent cytoplasmic transcription factors in cytokine signaling, that transduce signals from the cell membrane to the nucleus, where they activate gene transcription. STAT activation by phosphorylation is mediated by growth factors or cytokines, inducing STAT:STAT dimer formation between two monomers via reciprocal phosphoTyr formation. A member of the STAT family, STAT3 (Figure 1), has been found to be expressed at elevated levels in a large number of diverse human cancers, thus STAT3 represents a validated target for anticancer drug design. Understanding the dynamics of the STAT3 dimer interface, accounting for both protein-DNA and protein-protein interactions, with respect to the dynamics of the latent, unphosphorylated STAT3 monomer, is important for designing potential small-molecule inhibitors of the activated dimer.
The results of molecular dynamics (MD) simulations of the activated STAT3 homodimer:DNA complex, and latent unphosporylated STAT3 monomer in explicit water have been studied. Careful analysis of the data obtained from MD simulations over a 35 ns time-frame has revealed the dynamics of the macromolecular complex at the atomistic level; how the transcription factor interacts with the DNA, the nature of the conformational changes, and the way function may be affected. Further analysis of the dimer interface, with a main focus on the protein-DNA interaction, including the water molecules, has revealed the key residues contributing to the recognition events involved in STAT3 protein-DNA interactions. Moreover, locations of the majority of mutations in the DNA-binding domain are found at the protein-DNA interface. In particular, we have been able to map out these mutations in detail and relate them to specific protein-DNA contacts. Their structural stability and importance will be described, along with a discussion of how this model is being used to assist in the discovery of novel small-molecule inhibitors.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2323. doi:10.1158/1538-7445.AM2011-2323
Abstract 2331: Role of MMP expression in the effect of Plk4 on cell migration and invasion
Authors: Brashavitskaya Volha , Rosario Carla O. , Dennis James W. , Swallow Carol J. 
Published: June 2012

Abstract
Plk4 is a haploinsufficient tumor suppressor in mice (Ko et al, Nature Genetics, 2005). Plk4+/− mouse embryonic fibroblasts (MEFs) spontaneously immortalize in culture and become tumorigenic by passage 15 (Rosario et al, PNAS, 2010). We investigated the secondary genetic alterations associated with tumorigenicity.
Early passage (P3) Plk4+/+, P3 Plk4+/− and late passage (P15) Plk4+/− MEFs were compared by genome-wide expression array (Illumina). When differentially expressed genes were organized by biological function, increased cell proliferation and death (p=2.13E10-1.31E02, p = 2.52E07-1.14E02 respectively), and decreased cell motility (p = 3.74E07-1.27E02) in the P15 MEFs were predicted. An independent array analysis comparing tumorigenic (T) to nontumorigenic (NT) Plk4+/− MEFs showed a pattern of altered gene expression predictive of decreased motility in the T MEFs. These results suggested the hypothesis that Plk4 modulates cell motility. To directly test this hypothesis in functional assays we measured cell spreading, scratch-wound healing and transwell migration through Matrigel; in all these assays P3 Plk4+/− were inferior to P3 Plk4+/+ MEFs. We hypothesized that altered MMP expression was one mechanism for the difference observed in migration, and tested this by comparing MMP-13,-10 and -3 expression as shown in the Table. Plk4 status was associated with altered expression of MMPs; in particular, MMP-13 expression was confirmed to be significantly reduced in P3 Plk4+/− compared to P3 Plk4+/+ MEFs by RT-qPCR.

Our results indicate that Plk4 regulates cell motility and invasion. One potential mechanism is through upregulation of MMP-3,-10, and -13 expression. To further elucidate the molecular mechanisms of Plk4 related carcinogenesis we will next directly determine the effect of Plk4 on MMP activity and correlate this with migration and invasion.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2331. doi:10.1158/1538-7445.AM2011-2331
Abstract 2334: TWIST1, a B-RAF effector, promotes melanoma cell invasion
Authors: Weiss Michele B. , Aplin Andrew E. 
Published: June 2012

Abstract
Metastatic melanoma is the deadliest form of skin cancer and a paradigm for highly aggressive, chemotherapy-resistant tumors. Therefore, determining the factors impacting melanoma advancement toward metastasis is an important and clinically-relevant task. The TWIST1 protein is up-regulated in melanoma and its expression correlates strongly with poor clinical prognosis. We tested the role of high TWIST1 expression in traits associated with the progression of melanoma, as well as sought to delineate the mechanism underlying TWIST1 up-regulation. Our data shows that TWIST1 protein levels are higher in melanoma cells, especially invasive lines, compared to normal melanocytes. To evaluate the biological relevance of TWIST1 expression, we generated invasive melanoma cell lines depleted of TWIST1 by shRNA and non-invasive melanoma cell lines which constitutively overexpress TWIST1. First, we utilized these cell lines in standard Matrigel invasion assays through boyden chambers. Depletion of TWIST1 in several invasive melanoma cell lines significantly reduces Matrigel invasion by approximately 40-50%. The inverse phenotype is apparent when TWIST1 is overexpressed in low TWIST1-expressing, non-invasive melanoma cell lines. Additionally, we tested the effect of altered Twist expression in 3D collagen spheroid outgrowth assays, which mimic both tumor architecture and the in vivo collagen-rich dermal layer. We have found significant reduction of spheroid outgrowth when invasive cell lines are depleted for TWIST1 as well as increases in outgrowth when non-invasive cells overexpress TWIST1. Alterations to spheroid outgrowth were not as a result of apoptotic changes or proliferative rate as assessed by live/dead and EdU staining. Importantly, the mechanisms regulating high TWIST1 expression in melanoma are unclear. A comparison between wild-type and mutant B-RAF melanoma cell lines demonstrates that TWIST1 is more highly expressed in mutant B-RAF cells. We have found that disruption of B-RAF/MEK signaling, through siRNA/shRNA knockdown or pharmacological inhibition, strongly represses TWIST1 at the mRNA and protein level. An area of active investigation is the determination of the transcription factor responsible for TWIST1 regulation downstream of mutant B-RAF in melanoma. The data generated from these studies will allow for a greater understanding of the role and regulation of TWIST1 during the progression of melanoma towards metastasis. In addition, it may highlight TWIST1 as an attractive molecule/pathway for novel targeted therapies for melanoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2334. doi:10.1158/1538-7445.AM2011-2334
Abstract 2339: Overexpression of PKCα in T47D breast cancer cells induces migration via p120-catenin transcriptional downregulation
Authors: Perez White Bethany E. , Zhao Huiping , Tonetti Debra A. 
Published: June 2012

Abstract
Several factors have been identified that influence epithelial-mesenchymal transition (EMT) in breast cancer cells. We previously reported that overexpression of protein kinase C α (PKCα) in breast cancer predicts tamoxifen resistant secondary tumors (Tonetti, 2003). In T47D breast cancer cells, stable overexpression of PKCα (T47D/PKCα) leads to hormone-independent growth as well as tamoxifen resistance (Chisamore, 2001). In our current study we report that PKCα overexpression increases the metastatic potential of breast cancer cells through induction of a nonclasssical EMT. T47D/PKCα cells are morphologically distinct from T47D/neo cells and do not retain the cuboidal structure of epithelial breast cancer cells. Overexpression of PKCα resulted in significantly induced migratory capabilities in the Boyden chamber assay and PKC activation by phorbol 12-myristate 13 acetate further enhanced T47D/PKCα cell migration. Pharmacological inhibition with the classical PKC inhibitor Go6976 significantly reduced the migratory capacity of T47D/PKCα cells. Transient siRNA-mediated knockdown of PKCα (120 h) significantly reduced both basal and NIH3T3 fibroblast conditioned media-induced T47D/PKCα cell migration. Levels of adherens junction proteins E-cadherin, α-E-catenin, β-catenin and p120-catenin were significantly downregulated in T47D/PKCα cells compared to T47D/neo cells as determined by western blot. Levels of E-cadherin protein were restored by more than 50% after 168 h of PKCα knockdown in T47D/PKCα cells. While SYBR green RT-qPCR revealed that E-cadherin transcripts were significantly higher in T47D/PKCα cells compared to T47D/neo control cells, there was no change in expression of β-catenin or α-E-catenin transcripts. However, p120-catenin transcripts were significantly lower in T47D/PKCα cells compared to T47D/neo cells. Treatment with the proteasomal inhibitor MG132 induces accumulation of E-cadherin but not p120-catenin. Taken together, these data suggest that PKCα may be responsible for EMT in breast cancer cells through upstream signaling that leads to transcriptional inhibition of p120-catenin and subsequent degradation of E-cadherin protein. Further, PKCα expression may not only be predictive of tamoxifen-resistance and hormone-independent growth but also of increased potential for metastasis.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2339. doi:10.1158/1538-7445.AM2011-2339