bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting DNA Replication before It Starts: Cdc7 as a Therapeutic Target in p53 Mutant Her2 and Triple Negative Breast Ca.
Authors: Sainsbury R. , Proctor I. , Rodriguez S. , Loddo M. , Tudzarova S. , Stoeber K. , Williams G. 
Published: December 2010

Abstract
Based on protein expression profiles of core regulatory proteins involved in the G1–S and G2–M phase transitions, we have identified three distinct cell cycle phenotypes in a series of 200 breast cancers: (I) a G0 “out-of-cycle” state (18% of cases); (II) a G1 arrested/delayed state (24% cases); and (III) accelerated S-G2-M phase progression (58% of cases). The accelerated cell cycle progression phenotype had a higher risk of relapse when compared with G0 and G1-delayed/arrested phenotypes (HR=3.90 (1.81-8.4, p&lt;0.001) and was associated with Her2 and triple negative subtypes (p&lt;0.001). High-grade tumours with the G1 delayed/arrested phenotype showed an identical low risk of relapse compared with well-differentiated G0 tumours. In addition to its prognostic significance, the cell cycle phenotype also impacts on individualised therapeutic decisions. It is only patients showing the actively cycling, aggressive cell cycle phenotype that are likely to benefit from conventional chemotherapeutic S- or M-phase-directed agents or from the new generation of targeted cell cycle inhibitors that are now entering clinical trials.The DNA replication initiation factor Cdc7 is an emerging anti-cancer target. Cdc7 inhibition results in an abortive S phase and potent cancer cell killing. Specificity is based on normal cells undergoing a reversible G1 arrest following Cdc7 inhibition due to activation of a novel cell cycle checkpoint that is lost or impaired in cancer cells. Our analysis of the molecular circuitry underlying this replication origin activation checkpoint reveals that G1 arrest is dependent on three non-redundant checkpoint axes coordinated through the Forkhead transcription factor FoxO3a and p53. We show that only breast cancers displaying the accelerated cell cycle phenotype express elevated Cdc7 levels and are therefore highly represented in p53 mutant Her2-subtype and triple negative tumours. Breast cancers of the luminal subtype expressing low levels of Cdc7 undergo a cytostatic G1 arrest after Cdc7 inhibition due to their p53 wild type status, a checkpoint response mimicking untransformed cells. In contrast Her2 and triple negative tumours show a marked response to Cdc7 inhibitors with potent cancer-cell-specific killing as a result of (i) overexpression of the target protein and (ii) impairment of the origin activation checkpoint due to p53 lesions. Thus integrating cancer cell cycle phenotypic data with a molecular analysis of the origin activation checkpoint serves as a predictor of response to pharmacological Cdc7 inhibitors.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2148.
Cyclin D1 Is a Direct Target of JAG-Mediated Notch Signaling in Breast Cancer.
Authors: Reedijk M. , Reedijk M. , Reedijk M. , Cohen B. , Shimizu M. , Ng N. , Bukhman Y. , Pan J. , Dering J. 
Published: December 2010

Abstract
We have previously demonstrated that expression of the Notch ligand, JAG1 is associated with the basal breast cancer phenotype and disease recurrence. Herein we report on a genomics approach to elucidate mechanisms downstream of JAG1 that promote breast cancer growth. In a survey of 46 breast cancer cell lines we found that triple negative (TN; basal and mesenchymal ER-, PR- and Her2-negative) lines express JAG1 at significantly higher levels than do HER2+ or luminal (ER+) Her2- cell lines. The TN breast cancer cell lines HCC1143 and MDA MB231, which express JAG1 and demonstrate growth inhibition with RNA interference-induced down-regulation of JAG1, were selected for further study. We used microarray profiling of tumor cells transfected with JAG1 siRNA to identify JAG1-regulated genes. Differentially expressed genes (p ≤ 0.005; fold change ≥ 1.5) were identified for further study. Among the JAG1-regulated genes identified, cyclin D1 was found to be a direct target of NOTCH1 and NOTCH3. We show that JAG1 down-regulation results in reduced cyclin D1 expression, reduced direct binding of Notch to the cyclin D1 promoter, and inhibition of cell cycle progression through the cyclin D1-dependant G1/S check-point. Furthermore, we show that cyclin D1 and JAG1 expression correlate in basal breast cancer expression data sets. These data suggest a model whereby JAG1 promotes cyclin D1-mediated proliferation of TN breast cancer cells.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2150.
Function of HES6 an Inhibitor of HES1, in the Breast Cancer Cell Lines T47D and MCF-7 Is to Up-Regulate E2F-1 and Increased Proliferation.
Authors: Strom A. , Hartman J. , Lam E. , Lin C. , Gustafsson J. , Gustafsson J. 
Published: December 2010

Abstract
Hormone resistance remains as a major obstacle in breast cancer treatment. The majority of breast tumors are dependent on estrogens to grow, therefore anti-estrogens such as Tamoxifen is an effective treatment option. We have found that a transcription factor Hes6, earlier described in the nervous tissue, is up-regulated in hormone-independent breast cancer cells compared to normal estrogen sensitive breast cancer cells. By using a lenti-virus system, we have over-expressed Hes6 in T47D cells which are estrogen sensitive. This resulted in increased proliferation. We also found that estrogen treatment of MCF-7 breast cancer cells induced expression of endogenous Hes6 in the G1-phase. We could not find any binding of estrogen receptor α to the HES6 gene but instead found a binding site up-steam of the promoter in the ASCL1 gene. ASCL1 is a known inducer of HES6 and we are showing that ASCL1 is up-regulated by 17β-estradiol in MCF-7 cells. To find the mechanism behind the tumorogenic effects of Hes6, we analysed important factors of the cell-cycle. We found that the G1-phase factor E2F-1 was up-regulated in response to increased Hes6 expression. Since HES6 have been shown to be an inhibitor of HES1, this is in agreement with a previous study where we found that HES1 inhibited proliferation by binding to the promoter of and down-regulating E2F-1 expression. E2F-1 is an important limiting factor in late G1-phase of the cell cycle and can drive cell proliferation.We believe that the HES1-HES6 interplay is important in antiestrogen-resistant breast cancer. Studies are now ongoing to investigate if Hes6 is up-regulated in estrogen-independent human breast cancer samples.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2153.
nWASP, the Neural Wiskott-Aldrich Syndrome Protein, Plays a Pivotal Role in the Control of Endothelial Migration and Angiogenesis.
Authors: Jiang W. , Martin T. , Mansel R. 
Published: December 2010

Abstract
Introduction. nWASP, the neural Wiskott-Aldrich Syndrome Protein, is a member of the Wiskott-Aldrich syndrome (WAS) protein family which are known regulators of actin polymerization. Via interactions with actin, ERM (ezrin/moesin/radixin) family proteins, and other cytoskeletal associated proteins, nWASP is a key cell migration mediator. It has been shown that nWASP is aberrantly expressed in human breast cancer and that a reduction of nWASP is linked to a poor clinical outcome. Over-expression of nWASP in breast cancer cells also reduces their aggressiveness in vitro. In the present study, we investigated the potential influence of nWASP on the biological functions of endothelial cells and the angiogenic aspect of endothelial cells.Materials and methods. A panel of human cell lines of variety origins (n=43) were screened for the presence/absence of nWASP expression. A human vascular endothelial cell line, HECV, was found to be negative for nWASP expression and was chosen as a cell model in the present study. An expression construct for human nWASP was prepared using a mammalian expression vector, pcDNA3/V5/GFP/TOPO vector. HECV cells were transfected with the expression construct, or control vectors. The impact of nWASP over-expression in the endothelial cell line on the adhesiveness, migration and in vitro angiogenesis was assessed using a panel of in vitro models.Results. HECV cells, following transfection with the nWASP construct, successfully expressed nWASP, a subline subsequently established from which was so named as HECVnWASPexp7. Using an electric cell impedance sensing (ECIS) method, it was shown that HECVnWASPexp7 cells showed a significantly reduced adhesiveness to matrix surface (333.4±1.4 ohm), p&lt;0.01 when compared with the wild type cells (HECVwt 419.7±1.6 ohm) and transfection control (HECVpControl 387.9±1.46 ohm). In a similar fashion, HECVnWASPexp7 cells also displayed a marked reduction in cell migration when compared with control cells. Using an in vitro microtubule formation assay, it was shown that both HECVwt and HECVpControl cells responded well in their microtubule formation to an angiogenic factor, hepatocyte growth factor (HGF). However, HECVnWASPexp7cells were less responsive to HGF when assessed for microtubules. We have further shown that in response to an nWASP inhibitor, Wiskostatin, HECVnWASPexp7 cells markedly increased their tubule formation, a clear contrast to the wild type and control cells.Conclusion. It is concluded that nWASP is a key regulator of the migratory property of vascular endothelial cells and that this effect on cell migration is reflected by changes in the angiogenic activities of the cells. Collectively, nWASP is a potential intrinsic angiogenic regulator in endothelial cells.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2156.
Impact of IL17B on Endothelial Cells and Angiogenesis.
Authors: Sanders A. , Guo X. , Mason M. , Jiang W. 
Published: December 2010

Abstract
Introduction:Tumour angiogenesis plays a vital role in cancer development and spread. In the current study, IL17B was found to be unregulated in endothelial cells in response to Hepatocyte Growth Factor (HGF). IL17B shares structural similarities to IL17A, which has been previously proposed to promote angiogenesis and tumourgenicity, though currently the role of this cytokine in cancer or angiogenesis is largely unknown.Methods:HECV gene expression in response to HGF treatment was examined over a wide range of genes using micro array analysis to detect differential gene expression over the U133+2 chip. Recombinant human IL17B (rhIL17B) was subsequently used to treat human HECV endothelial cells over a range of concentrations. The impact of rhIL17B on HECV cell motility and angiogenic potential was assessed using Matrigel migration/wounding and tubule formation.Results:Micro array analysis detected a significant increase in IL17B expression in response to 4 hour treatment of HECV human endothelial cells with 40ng/ml HGF (p &lt; 0.05 vs HGF untreated HECV cells). rhIL17B negatively influenced HECV tubule formation at the higher concentrations with substantial reduction in tubule formation being seen following treatment with 250ng/ml rhIL17B. Higher concentrations of rhIL17B were also seen to reduce the capacity of HECV cells to migrate in a scratch wounding assay and significant differences in migrated distance were observed following 75 minute incubation (P &lt; 0.05 vs control untreatment group).Conclusions:Micro array analysis suggests that IL17B gene expression in the HECV human endothelial cell line can be upregulated in response to treatment with HGF. Subsequently high levels of rhIL17B were seen to negatively impact on the tubule formation and migratory capacity of this cell line. Together this data suggests that IL17B is unlikely to play a key role in the pro-angiogenic response initiated through HGF signalling but at higher concentrations may itself be able to negatively impact the angiogenic potential of the HECV endothelial cell line.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2157.
Mast Cells Positive to Tryptase Correlate with Angiogenesis in Early Breast Cancer.
Authors: Troilo S. , Patruno R. , Zizzo N. , Troilo P. , Catino A. , Gadaleta C. , Ranieri G. 
Published: December 2010

Abstract
Background: Literature data indicate that mast cells (MCs) are involved in tumor angiogenesis due to the release of several pro-angiogenetic factor among which tryptase, a serine protease stored in MCs granules, is one of the most active. In benign breast lesions and in primary breast cancer, tryptase-positive MCs are more numerous as compared to chymase-positive MCs. Recently, it has been demonstrated that tryptase-positive MCs are involved in angiogenesis in sentinel lymph nodes with micrometastases from patients with breast cancer. However no data has been published regarding the correlations between MCs positive to tryptase and angiogenesis in primary breast cancer tissue. In the present study, we have evaluated the correlations between the number of MCs positive to tryptase (MCDPT), the area occupied by MCs positive to tryptase (MCAPT), microvascular density (MVD) and endothelial area (EA) in a series of T1-3, N0-2, MO female breast cancer, by means of immunohistochemistry and image analysis methods.Material and Methods: Bioptic specimens were collected from 88 female breast cancer patients who had undergone breast cancer surgery. For the evaluation of MCDPT, MCAPT, MVD and EA, a three layer biotin-avidin-peroxidase system was utilized. Briefly, six-micrometers thick serial sections of formalin-fixed and paraffin-embedded bioptic tumor samples were obtained. Then sections were microwaved at 500 W for 10 min. and treated with a 3% hydrogen peroxide solution. Sections were incubated with human-specific monoclonal antibodies anti-CD34 (QB-END 10; Bio-Optica Milan, Italy) diluted 1:50 for 1h at room temperature and anti-tryptase (clone AA1; Dako, Glostrup, Denmark) diluted 1:100 for 1h at room temperature. The bound antibody was visualised using biotinylated secondary antibody, avidin-biotin peroxidase complex, and and 3-amino-9-ethylcarbazole. The five most vascularized areas ("hot spot") were selected at low magnification and both individual vessels were counted at x 400 magnification. In serial sections each single tryptase-positive MC was counted. Single brown stained endothelial cells and red MCs positive to tryptase were also evaluated in terms of immunostained area at x 400 magnification.Results: Our data demonstrated a significantly (r= ranging from 0.78 to 0.89; p: ranging from 0.001 to 0.002 by Pearson's analysis respectively) correlation between MCDPT, MCAPT, MVD, EA each to other, whereas no correlation concerning MCDPT, MCAPT, MVD, EA and the main clinical pathological features was found.Discussion: These preliminary results suggest that tryptase-positive MC play a key role in breast cancer angiogenesis and that inhibition of tryptase may be a new antiangiogenic strategy for the treatment of breast cancer.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2159.
Blockade of Notch Signaling by GSI Induces Apoptosis in Human Breast Cancer Cells through Various Molecular Mechanisms Involving Survivin and BH3-Only Members of the Bcl-2 Family.
Authors: Séveno C. , Campone M. , Campone M. , Juin P. , Barillé-Nion S. 
Published: December 2010

Abstract
The Notch pathway is multifunctional and controls key nodes in cell signaling. In most cases, its deregulation has oncogenic effects, and aberrant activation of Notch signaling has been evidenced in breast cancer (Stylianou S, CR 2006). In particular, a functional Notch pathway appears to be of critical importance in the maintenance of basal breast cancer (Lee CW, CR 2008, BCR 2008). Moreover, because Notch signaling is repressed by both ER (Rizzo P, CR 2008) and HER2 (Osipo C, Oncogene 2008) oncogenic pathways, its reactivation during tamoxifen or trastuzumab treatment may restrain the efficiency of these inhibitors. Thus, Notch signaling inhibitors, such as competitive inhibitors of the g-secretase, GSI, that prevent proteolytic processing of the Notch receptor and the activation of its intracellular domain, are being actively investigated for the treatment of breast cancer, even though the mechanisms that might underlie their effects are still poorly understood.We first observed that GSI XII (z-Ile-Leu-CHO) was more effective in inducing apoptosis, as a single agent, on ER-/PR-/Her2- breast cancer cell lines than GSI X (z-Leu-Leu-Nle-CHO). This effect was associated with decreased expression of the anti-apoptotic proteins Survivin and XIAP and increased expression of, depending on cell lines, either NOXA or PUMA, two pro-apoptotic BH3-only members of the Bcl2 family.In the opposite, ER+ breast cancer cell lines were more sensitive to induction of apoptosis by GSI X, but this was manifest only in combination with Tamoxifen. Interestingly, Tamoxifen treatment of these cells induced both GSI X-sensitive Notch transcriptional activity and Survivin expression. Moreover, Survivin knock-down by RNA interference increased Tamoxifen sensitivity. Thus, Survivin might be an important actor of survival signal triggered by Notch (re)activation during ER pathway inhibition. Our results corroborate previous data showing the interest to use GSI in breast cancer but underline also the need to unravel the sub-type and context dependent molecular events involved in their biological activity.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2160.
mTORC1 Activity Contributes to the Mcl-1 Dependence of HER2 Amplified Breast Cancer Cells.
Authors: Campone M. , Campone M. , Noel B. , Gouraud W. , Gouraud W. , Jézéquel P. , Jézéquel P. , Barillé-Nion S. , Juin P. 
Published: December 2010

Abstract
Whether or not certain subtypes of mammary tumors specifically rely on a limited number of anti-apoptotic mechanisms for their maintenance, and how therapy might affect these mechanisms, is currently ill characterized.We have analyzed published gene-expression profiles of breast cancer patients for which HER2 status, evaluated by immunohistochemistry, was also available. A statistically significant enrichment in the expression of Mcl-1 in HER2 amplified breast tumors, compared to other breast tumors, was found.In vitro, knock down of Mcl-1 expression by RNA interference proved sufficient to induce apoptosis in the HER2 amplified cell line BT474. Combined RNA interference experiments showed that apoptosis induced by Mcl-1 knock down in these cells (ie, their “Mcl-1 dependence”) relied on the expression of the pro-apoptotic BH3-only protein Bim. This indicates that the Bim/Mcl-1 balance (possibly regulated by direct physical interactions between these two proteins) constitutes an integrating point towards which the numerous survival pathways that are known to lie downstream of HER2 should converge, to the very least in these cells.While seeking for signaling pathways that might significantly affect Mcl-1 dependence downstream of HER2, using diverse small molecule inhibitors, we found that mTORC1 inhibition in BT474 cells not only leaves Mcl-1 expression levels unaltered, but also prevents induction of apoptosis by Mcl-1 depletion. mTORC1 inhibition enhances the activity of the survival kinases Akt and ERK (p44 and p42). HER2 signaling is involved in this activation, since it is prevented by trastuzumab treatment.These data suggest that, due to the structure of the signaling network mTORC1 is embedded in (which includes the HER2 driven negative feedback loop described here), its activity locks HER2 amplified cells in a Mcl-1 dependent state. They also imply that combining inhibitors of mTORC1 with inhibitors of the HER2 pathway (such as trastuzumab) might restrain the effects on cell survival of the former, and enhance their clinical efficiency in HER2 amplified breast cancers.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2161.
The Cell of Breast Cancer Origin Affects Tumor Estrogen Receptor Status.
Authors: Toneff M. , Du Z. , Li Y. 
Published: December 2010

Abstract
It has been known for some time that breast cancer phenotype is dependent upon the initiating oncogene. However, it has only recently been demonstrated that breast cancer phenotype, including tumor histopathology, gene expression profile, and metastatic potential, may also depend upon the cellular subtype from which a tumor arises. Breast tumor estrogen receptor (ER) status is a common prognostic factor, and approximately 70% of all breast tumors are ER+; that is, they expresse ER in ≥5% of tumor cells. However, it remains unknown which factors determine breast cancer ER status. It is possible that the cell of tumor origin plays a role in determining the ER status of the resulting tumor. Our lab has developed a method to somatically introduce oncogenes into a developmentally normal mouse mammary gland with temporal control using the modified avian retrovirus RCAS. We have generated transgenic mice that express the RCAS receptor TVA under mammary cell selective markers and demonstrated our ability to infect individual cells and induce mammary tumors. In this study we used an RCAS vector encoding polyoma virus middle T antigen (PyMT) to infect transgenic adult MMTV-tva or WAP-tva mice. The MMTV LTR is though to be active in several different mammary cell types including luminal epithelial, progenitor, and stem cells. WAP is primarily active in more highly differentiated mammary epithelial cells. Tumors induced by RCAS-PyMT differ in histopathology between the two lines. Those arising in MMTV-tva mice have a predominately solid morphology, while those arising in WAP-tva mice display a predominately papillary morphology. Interestingly, we found that the majority of tumors arising in MMTV-tva mice are ER+ (61%), while tumors arising in WAP-tva mice are predominately ER- (95%). Our data suggest that tumors induced by the same oncogene from distinct cellular subtypes in the mouse mammary epithelium can significantly vary in histopathology, and that tumor ER status can be dependent upon the cell of tumor origin.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2163.
A Prospective Study of Breast Cancer Incidence and Stage Distribution in Women with a BRCA1 or BRCA2 Mutation under Surveillance with and without Magnetic Resonance Imaging.
Authors: Warner E. , Hill K. , Causer P. , Plewes D. , Jong R. , Yaffe M. , Wong J. , Wright F. , Sun P. , Narod S. 
Published: December 2010

Abstract
Introduction: The sensitivity of MRI for the detection of pre-clinical breast cancer exceeds that of mammography and of other screening tests. If MRI screening leads to reduced mortality in women with a BRCA1 or BRCA2 mutation, then it is expected that the incidence of advanced stage breast cancers should be reduced in a cohort of women undergoing regular MRI screening, compared to conventional screening.Methods: We followed 1275 women with a BRCA1 or BRCA2 mutation for a mean of 3.2 years for incident breast cancers. 445 women were enrolled in an MRI screening trial in Toronto and 830 controls, from elsewhere in Canada and the United States, underwent conventional screening. The cumulative incidences of DCIS, of early-stage and of late-stage breast cancer were estimated at six years in the two cohorts.Results: There were 41 cases of breast cancer diagnosed in the MRI-screened cohort and 76 cases of breast cancer diagnosed in the control cohort. The cumulative incidence of DCIS or stage I breast cancer at six years was 12.7% in the MRI-screened cohort and was 9.5% in the control group (p = 0.02; log rank test). The cumulative incidence of stage II – IV breast cancers at six years was 2.0% in the MRI-screened cohort and was 7.1% in the control group (p = 0.02; log rank test). The adjusted hazard ratio for the development of stage II – IV breast cancer associated with membership in the MRI-screened cohort was 0.30 (95% CI: 0.12 to 0.72; p = 0.008).Conclusion: Annual surveillance with MRI is associated with a significant reduction in the incidence of advanced stage breast cancer in BRCA1 and BRCA2 carriers.Funding for this study is generously provided by the Canadian Breast Cancer Research Alliance.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 26.