bluuebunny/crossref_metadata_2025_split huggingface dataset:
P5-03-04: Circadian Modulation of Estrogen Receptor alpha Promoter Activity.
Authors: Villa LM , Santos CS , Cousins S , Finkielstein CV 
Published: June 2012

Abstract
The circadian clock is a molecular mechanism that synchronizes environment variations with physiological changes. Disruption of the circadian clock has been linked to increased risk in diseases and a number of disorders (e.g. jet lag, insomnia, coronary heart disease and cancer). Period 2 (PER2), a circadian protein, is at the center of the clock's function. The complete loss of per2 has been shown to be common in several types of cancer including breast and ovarian. Epidemiological studies established a correlation between circadian disruption and the development of estrogen dependent tumors. The expression of estrogen receptor alpha (ERa) mRNA oscillates in a 24-hour period and, unlike PER2, ERa peaks during the light phase of the day. Because up regulation of ER relates to tumor development, defining the mechanisms of ERa expression will contribute to our comprehension of cellular proliferation and regulation of normal developmental processes. The overall goal of this project is to investigate the molecular basis for circadian control of estrogen receptor alpha (ERa) transcription.
Transcriptional activation of ERa was measured using a reporter system in Chinese Hamster Ovary and MCF-7 cell lines. Data show that PER2 influence ERa transcription through a non-canonical mechanism independent of its circadian counterparts. Promoter analysis using the Alibaba 2.0 suite revealed the presence of various putative novel partners. Among them, OCT-1 was found to directly interact with Per2, in vitro, and with corresponding response element within the ERa promoter. The predicted binding site of OCT-1 is 267 bps upstream of the promoter. Pull-down assays were used to map direct interaction of various PER2 recombinant proteins and the DNA-binding domain of OCT-1. Radiolabeled OCT-1 was found to bind to the C-terminal end of PER2. Electrophoretic mobility shift assays were used to determine direct binding of OCT-1 to the promoter. ChIP assay confirmed the recruitment of PER2 to the estrogen promoter by OCT-1. Fluorescence anisotropy and surface plasmon resonance were employed to establish the binding affinity of OCT-1 to the ERa promoter and PER2. OCT-1 was found to have a high affinity for the ERa promoter (∼10 nM). Furthermore, OCT-1 recruits PER2 to the estrogen promoter. Preliminary data suggests that the transcription factor PER2 might play a role in the regulation of the estrogen promoter.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-03-04.
P5-04-01: BP1, a Homeotic Transcription Factor, Indirectly Upregulates ER-alpha in ER Positive Cell Lines.
Authors: Berg PE , Awate S , Kirolikar SP 
Published: June 2012

Abstract
Background: BP1 is a member of the homeobox gene family of transcription factors. Our recent studies have shown that BP1 may play a role in breast cancer cell survival, aggressiveness and metastasis. BP1 protein (pBP1) is expressed in 80% of invasive ductal breast tumors, including in 57% of ER positive and 89% of ER negative tumors. BP1 overexpression results in a more aggressive phenotype in breast cancer cells and larger tumors in women with breast cancer. We also observed the presence of mammary tumors in mice without estrogen supplementation after injection of MCF7 cells overexpressing BP1 compared with unsupplemented mice receiving MCF7 cells containing an empty vector. Our goal was to determine the pathway by which BP1 might cause this decrease in estrogen dependence of MCF7 cells. ER-alpha is a nuclear hormone receptor activated by estradiol and is a major target of anti-estrogen therapy. It is tightly regulated at the genomic and the non-genomic levels. Increased stability of ER-alpha is one mechanism by which cells can become ER-alpha independent. One way of altering ER-alpha stability is via p300 and BRCA1 since p300 acetylates and stabilizes ER-alpha, while BRCA1 destabilizes ER-alpha. We have previously shown that BP1 transcriptionally down-regulates BRCA1, suggesting that pBP1 may participate in this pathway.
Materials and methods: Protein levels of BRCA1, p300, pS2, pBP1 and ER-alpha were determined by Western Blot analysis. RNA levels were measured by real-time PCR. A ChIP assay was performed to confirm binding of pBP1 to the EP300 gene and binding of ER-alpha to BP1. MCF7 parental cell lines were treated with 10nM E2 to induce the expression of pBP1. Experiments involving effects of siBP1 on p300 expression are underway.
Results: Our data demonstrate that MCF7 ER+ cells engineered to overexpress BP1 exhibit increased ER-alpha protein, increased p300 and decreased BRCA1 protein as compared with control cells containing an empty vector and grown under the same conditions. Increased ER-alpha levels correlated with increased pS2 expression, a known downstream target of ER, demonstrating that there is more functional ER-alpha protein in cells overexpressing BP1. ChIP assays showed that pBP1 binds in the first intron of EP300-Histone acetyltransferase (p300). ChIP assays also showed that ER-alpha binds to an estrogen response element (ERE) upstream of the BP1 gene. MCF7 parental cell lines, when serum starved and treated with E2, showed increased BP1 expression compared with cells grown in charcoal stripped serum. Thus, BP1 may increase the stability of ER-alpha by decreasing BRCA1 and increasing p300. Conclusions: pBP1 binds and transcriptionally activates p300, leading to increased ER-alpha stability, while also partially repressing BRCA1. Moreover, ER-alpha, via a feed-forward mechanism, binds to the BP1 gene and increases its expression.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-04-01.
P5-05-04: Bipshenol-A Modulates Estrogen Receptor Alpha and Compromises Tamoxifen-Induced Apoptosis.
Authors: Goodson III WH , Luciani MG , Sayeed A , Jaffee I , Moore II DH , Dairkee SH 
Published: June 2012

Abstract
BACKGROUND: Antiestrogens are important for treatment and prevention of breast cancer. Such drugs influence multiple pathways involved in regulation of cell survival — including apoptosis. In previous work, exposure of human, benign, high-risk donor breast epithelial cells (HRBECs) to the xenoestrogen (XE) bisphenol-A (BPA) induced gene expression changes predicting disruption of apoptotic signaling (Dairkee et al, Cancer Research 2008). Therefore, we hypothesized that antiestrogenic, pro-apoptotic effects of tamoxifen are likely modulated under the influence of XEs. Because the environmental XE, BPA is routinely detected in a large percentage of random human blood samples, we employed functional tests to determine whether BPA interferes with tamoxifen-induced apoptosis in XE-exposed HRBECs.
METHODS: With IRB approval and written informed consent, HRBECs were obtained by random periareolar fine needle aspiration (RPFNA) from women who were high risk on the basis of personal or family history of breast cancer, breast density, or high-risk histology. Primary HRBEC cultures were treated for one week with a low concentrations of BPA corresponding to levels reported in human body fluids. Estrogen Receptor (ER)-α and -β were measured by Western blot (n=6). Altered response to tamoxifen toxicity was measured by analyzing quantitative changes in the Annexin V-positive apoptotic cell population (n=8).
RESULTS: After one-week exposure to BPA, ER-α increased in six of six cases, ER-β decreased in 5 of 6 cases, and we observed a 25 percent reduction in tamoxifen-induced apoptosis. Prior exposure to BPA at the high concentration range detected in the human population reduced tamoxifen efficacy by 50 percent. There was a dose response of evasion of apoptosis to increasing concentrations of BPA (P&lt;0.001, two-sided test for slope fixed effect in a linear mixed effects regression). Prior exposure to another XE, methylparaben (MP), caused a similar dose-dependent decline in tamoxifen-induced apoptosis (p&lt;0.001).
CONCLUSION: BPA and MP, in a range of concentrations measured in humans, prevent tamoxifen-induced apoptotic cell death. For BPA this involves upregulation of ER-α and downregulation of ER-β. Because these XEs are widespread in the American population, they may play a role in limiting the prophylactic and therapeutic efficacy of tamoxifen and other hormone-based therapies.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-05-04.
P5-05-06: Dysregulation in the Transport of Iron and Haem Is Implicated in the Aetiopathogenesis of Breast Cancer.
Authors: Roe T , Hoar F , Tselepis C 
Published: June 2012

Abstract
Backround: Mounting evidence implicates iron in the development of a number of cancers, including breast. The responsible mechanism is poorly understood in breast cancer, although recent work has demonstrated irregular expression of various molecular iron transporters.
Materials and Methods: Immunohistochemistry on archived material was used to evaluate differences in expression of iron and haem exporters, importers and storage proteins between breast cancer, DCIS and normal breast tissue. The results were corroborated by Western blotting and RT-qPCR on protein and RNA samples generated from matched normal and cancer specimens collected at mastectomy. The ability of benign and malignant breast cells in vitro to accumulate excess iron in the presence of exogenous iron/haem was evaluated with a ferrozine assay. In addition the effect of exogenous iron and haem on cell phenotype in vitro was assessed in benign and malignant cell lines. Assays utilised included viability (MTT), proliferation (BrdU), migration, anchorage-independent growth (colony formation) and invasive capacity. These assays were then repeated in the presence of iron chelators to investigate their potential utility as a therapeutic modality.
Results: Statistically significant increases (p&lt;0.05) were observed in expression of the iron importers DCytB, DMT1 and TfR in breast cancer relative to normal tissue. Levels of the storage protein ferritin were also significantly raised. The iron exporters ferroportin and hephaestin were significantly under-expressed in breast cancer, while hepcidin (which induces exporter degradation) was over-expressed. Levels of the haem importer HCP1 and the exporters BCRP and FLVCR were all significantly down-regulated in cancer relative to normal.
Both benign and malignant breast cells were capable of importing excess iron, although only malignant cells could import excess haem. Iron induced increased viability and proliferation in benign cells but had no effect on their migratory or invasive capability, or their ability to form colonies. Haem had no effect on benign cell phenotype. Iron and haem both had significantly positive effects on all these aspects of cell phenotype when introduced to malignant breast cells in vitro. Iron chelators were capable of abrogating these positive effects.
Discussion: Archived material and prospectively collected matched tissue pairs demonstrate that breast cancers exhibit altered expression of the proteins involved in transporting iron and haem through the cell. In vitro experiments reveal malignant cells to be capable of taking up both substances, which both appear to drive a more malignant phenotype. These in vitro changes can be reversed through the introduction of iron chelators, implying possible efficacy as a novel therapy in breast cancer.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-05-06.
P5-06-01: Gene Expression Analysis of Resistance to Bevacizumab in a VEGF-Reinforced Xenograft Model of ER-Positive Breast Cancer.
Authors: Gökmen-Polar Y , Toroni RA , Goswami C , Sanders KL , Mehta R , Sirimalle U , Tanasa B , Shen C , Li L , Ivan M , Badve S , Sledge GW 
Published: June 2012

Abstract
Background: Bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor (VEGF), had promising therapeutic efficacy in breast cancer. However, intrinsic or acquired resistance is common in the clinic. To improve our understanding of the underlying mechanisms of resistance to bevacizumab (BEV), we report the gene expression analysis of resistance to bevacizumab in a VEGF-overexpressing xenograft model of ER-positive breast cancer.
Methods: We developed a nude mouse xenograft model of resistance to anti-VEGF therapy with BEV in which MCF-7 control (ML20) or MCF-7 VEGF (MV165) transfectants were implanted in mammary fat pads, allowed to grow, then treated with BEV, with collection of tumor at early or late time points (while responding (R) to or progressing (NR) on anti-VEGF therapy). To elucidate differentially expressed gene profiling associated with tumor resistance to BEV, we performed whole-genome gene expression analysis (Human WG-6v2 Expression Beadchips, Illumina) and miRNA profiling (TaqMan ***ArrayHuman MicroRNAA+B Cards Set v3.0, Applied Biosystems). Validation of the chosen genes was performed using quantitative real-time RT-PCR (qRT-PCR).
Results: Gene expression analysis revealed differentially regulated genes in the MV165-NR group compared with the MV165-R group. Among the significant genes, Follistatin (FST) and HEY2 were the top genes upregulated in NR compared to R by ANOVA. Expression of HEY2 is induced by the Notch signaling pathway. Using qRT-PCR, we validated the expression of FST and Notch in our system. FST was significantly decreased (Fold change= −3.2; P=0.03) in the R group compared with vehicle in MV165 xenografts. In contrast to R group, FST was upregulated significantly (Fold change= 9.3; P=0.05) in the NR group. Notch4 displayed increased levels of expression in NR group, but it did not reach significance (P=0.23). In addition, correlation of mRNA and miRNA profiles showed that miRNAs targeting FST and Notch4 were differentially regulated in NR group compared to R group in MV165 xenograft tumors. Among the miRNAs, TGF-β-induced oncomiR miR-181a is up-regulated in NR and targets both FST and Notch4. Other miRNAs that target both Notch4 and FST include miR-1, miR-133a, miR-133b, and mir-449b. Conclusion: Our data serve as a potential mechanistic explanation for acquired resistance to bevacizumab. These data may shed light on the transitory effect of BEV observed in the E2100 firstline metastatic breast cancer trial, where VEGF-targeted therapy prolongs progression-free survival in metastatic breast cancer without improving overall survival.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-06-01.
P5-08-01: Quantitative Analysis of Strain Ratio of Microcalcification Lesions with Surgical Specimen Mammography.
Authors: Hung S-H , Chen R-C , Wu Y-T , Chen T , Lin C-H 
Published: June 2012

Abstract
Measurement of the strain induced by compression can be useful in the diagnosis of breast tumors. Microcalcification (MC) detected by mammography could be the only symptom of early breast cancers. The purpose of this study was to develop a quantitative method for a differential diagnosis of MC lesions based on the strain ratio (SR) obtained by applying different breast compression pressure during mammography.
Methods: This prospective study was conducted with institutional review board approval and the written informed consent was obtained. Twenty-five mastectomy specimens (24 for treatment of breast cancer and 1 from contralateral prophylactic mastectomy) with MCs were examined by digital mammography. There were 24 malignant MCs (mean size of 18.8 mm) detected in the 24 separate specimens, including 14 lesions of invasive carcinoma and 10 lesions of carcinoma in situ. Five benign MCs (mean size of 21.6 mm) were detected, including four lesions which coexisted with malignant MCs in the four separate specimens, and one was discovered in the prophylactic mastectomy specimen. Each specimen experienced four different magnitudes of compression force and the corresponding images were acquired for further analysis. Images in Digital Imaging and Communications in Medicine format (DICOM) were exported into custom software, written in Matlab, to contour the region of interest. Stress was defined as the force divided by the whole specimen area, and the square root of MC area was calculated to represent strain deformation. The SR was the slope of the best-fit line through the four points of each lesion. Histology of the MC was correlated with SR. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of SR for discrimination between benign and malignant MC.
Results: The SRs were higher in the malignant MC group (139.10 a.u.) than in the benign MC group (34.09 a.u.; p = 0.024). The SR between invasive carcinoma and carcinoma in situ showed no statistic significance (127.03 a.u. vs. 156.00 a.u.; p = 0.642). The area under the ROC curve for the diagnosis of benign and malignant MC was 0.825 (95% CI, 0.667 to 0.982).
Conclusion: This study demonstrated that the SR detected by mammography showed potential for distinguishing benign from malignant MCs. Further in vivo investigations of larger cohorts are necessary to validate these results.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-08-01.
P5-09-05: Non-Palpable Lesions Findings in a Breast Cancer Opportunistic Screening in South Brazil.
Authors: Rockenbach R , Rombaldi RL , Caleffi M 
Published: June 2012

Abstract
Introduction: Today breast cancer is a major public health challenge in developing countries with increasing mortality rates due to the lack of early detection programs and access to care. Mammography has been considered the most sensitive test for breast non-palpable lesions. The Brazilian National policy recommends mammography from age 50 and every two years. This study investigates only radiological findings in a set of women seeking for long term breast care surveillance.
Objectives: To evaluate patients characteristics of cases with non-palpable breast lesions.
Material and method: A prospective and transversal study was undertaken between March,2009 and April,2010 on 110 women with non-palpable breast lesions, diagnosed by mammography or ultrasound. Histo-pathological evaluation was performed in core biopsy specimen. The following variables were studied: pregnancy, parity, menarche, menopause, hormone replacement therapy, breast lesion location, tumor size, histopathology findings, mammographic and ultrasound classification — BI-Rads.
Results: 23,7% (n=26/110) out of 110 women were diagnosed with breast cancer and 76,3% (n=84/110) were diagnosed with benign mammary pathology. Mammography, according BIRads classification, strongly suggested (p&lt;0,000) the presence of benign and malign pathologies. In the breast cancer group, 14 were diagnosed with stage 1 (TNM), compared to the official data from INCA where stage I is 10% of the cases.

Conclusion: Mammographic screening reduces mortality by 30% after 50 years of age and also provides important benefit (20%) in younger women (40-49). Our study showed a cancer detection rate of 25,7% and 34,6%, respectively, demonstrating the importance of screening also in younger ages. Overall, the rate of biopsy positive was very satisfactory (1 out of 4 cases). Among the studied non-palpable breast lesions, our findings resulted in 53.8% stage I breast cancers (TNM) which reinforces the urgent need of a structured screening program in Brazil to save more lives.
Financial support: Avon Institute.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-09-05.
P5-13-01: Survival Outcome with Bevacizumab: Activation of the Phosphatidylinositol-3 Kinase (PI3K) Pathway Due to PIK3CA Mutations or PTEN Loss Makes a Difference.
Authors: Vidal M , Di Cosimo S , Torrejon D , Saura C , Gómez-Pardo P , Pérez-Garcia J , Muñoz-Couselo E , Bellet M , Sanchez-Olle G , De Mattos-Arruda L , Oliveira M , Tabernero J , Baselga J , Cortes J 
Published: June 2012

Abstract
Background
The PI3K pathway is known to regulate the transcription of Vascular Endothelial Growth Factor (VEGF) in endothelial and cancer cells. The inhibition of VEGF is the rationale behind the development therapy with anti-angiogenics. We investigated the activation of PI3K pathway, defined as PTEN loss and/or PIK3CA mutations, and the relationship with survival in metastatic breast cancer patients treated with the anti-VEGF monoclonal antibody bevacizumab.
Patients and methods: Records for patients with HER2 negative metastatic breast cancer (MBC), treated with bevacizumab from July 2005 to June 2010, and with known PI3K status were reviewed. Univariate and multivariate analysis were performed using SPSS 15.0.
Results: A total of 40 patients — 26 with and 14 without PI3K activation — were identified. Median age was 47 years (range 27–79). Median overall survival (OS) was 41.23 months (CI 95%: 27.29 — 55.18) and 66.23 months (CI 95%: 61.04 — 71.42) in patients with and without PI3K activation, respectively (p=0.04). Among patients with PI3K activation, OS was 34.13 months (CI 95%: 22.40 — 45.86) and 43.43 months (CI 95%: 26.9 — 59.97) in cases with PIK3CA mutations and PTEN loss, respectively. As compared to patients without PI3K activation, patients with PI3KCA mutations but not patients with PTEN loss showed a significant worse outcome (p=0.006 and p=0.3, respectively). In the multivariate analysis including grade, hormone receptor and Ki67 status, and total lines of treatment, the activation of PI3K activation proved to be an independent prognostic factor (p=0.03).
Conclusions: The activation of the PI3K pathway is significantly associated with decreased OS of MBC patients treated with bevacizumab. Prospective evaluation of PI3K activation on VEGF signaling with differential implication of PI3KCA and PTEN loss is warranted.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-01.