bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo magnetic resonance imaging of the progression of murine ductal carcinoma in situ: finding timescales and predictors of future invasion.
Authors: Jansen SA , Conzen SD , Newstead GM , Markiewicz EJ , Karczmar GS 
Published: December 2010

Abstract
Abstract #6011
Background: Understanding the natural history of breast cancer is important for effective patient management and treatment. For example, some evidence suggests that preinvasive ductal carcinoma in situ (DCIS) may be over-treated, since not all will progress to invasive cancer. Unfortunately, due to obligate surgical excision of newly diagnosed breast cancers, the natural history of disease is difficult to study in women. However, mouse models of breast cancer can serve as an alternative; the purpose of this study was to use magnetic resonance imaging (MRI) to investigate the progression of DCIS into invasive cancer in a transgenic model.&#x2028; Methods:12 SV40 Tag mice were imaged every 2-3 weeks (wks) starting at 10 wks of age. SV40 mice develop mammary cancer similar to DCIS and IDC, and usually live to 22 wks when they succumb to breast cancer. T1-weighted gradient echo images of inguinal mammary glands were obtained. DCIS lesions and invasive tumors were identified and volumes were measured over time. For each lesion we measured: the time at initial development (TDCIS and Ttumor), the growth rate of DCIS and invasive tumors (calculated from 'V=V0exp(αt)'), and for DCIS lesions that progressed to invasive tumors the progression time Tprog was measured.&#x2028; Results:DCIS (n=21) and invasive (n=16) tumors developed, at an average initial age of TDCIS =12.7±2.6 wks and Ttumor =16.3±3.1 wks, and at an initial volume of 0.3±0.2 mm3 and 1.7 mm3, respectively. The average growth rate for DCIS lesions was αDCIS= 0.08±0.23 wk-1, significantly smaller than that of invasive tumors (αtumor= 0.55±0.35 wk-1, p =0.001). 9/21 DCIS lesions progressed to invasive cancers in an average time of Tprog=4.56 ± 1.9 wks(Figure 1a). 11/21 DCIS did not progress within the study window and 5/21 were stable for over 8 wks (Figure 1b).&#x2028; &#x2028; The volume of DCIS was not a predictor of progression, but there was a trend for DCIS growth rate to be related to eventual development of invasiveness.&#x2028; Discussion:To our knowledge, the results reported here are the first direct measurements of the timescales and characteristics of progression from in situ to invasive carcinoma. Surprisingly, even in transgenic mice that are strongly pre-disposed to develop cancer, some DCIS lesions did not progress to invasive cancer. Interestingly, DCIS volume did not predict future progression to invasive tumors, but growth rate may have been a predictor. The methods and data here provide a foundation for using MRI in pre-clinical studies of early cancer progression, prevention and targeted treatment. Extensions of this pilot study may yield image-based biomarkers of progressing vs. indolent DCIS.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6011.
Novel roles of a transcription elongation regulator in mammary gland development and tumorigenesis.
Authors: Sreejith Janardhanan N , Sun J , Amleh A , Sun L , Wang L , Li R 
Published: December 2010

Abstract
Abstract #6013
Historically, transcriptional regulation in mammary gland development and breast cancer development is thought to primarily occur at the stage of transcription initiation. However, recent studies of genome-wide transcription suggest that the majority of “inactive” genes in human cells experience transcription initiation and many of them have binding of RNA polymerase at the promoter-proximal region. Thus, transcription elongation may represent a widespread, yet vastly under-appreciated step for mammalian gene regulation. Cofactor of BRCA1 (COBRA1), which was first identified as a BRCA1-binding protein, acts as an integral subunit of the negative elongation factor (NELF) complex to stall RNA polymerase II (RNAPII) during estrogen-stimulated transcription elongation. COBRA1 also shares a number of target genes for transcriptional regulation with BRCA1 in breast cancer cells. In support of its potential role in tumor suppression, COBRA1 is preferentially expressed in luminal epithelial cells in normal mammary ducts; and its reduced expression is strongly correlated with metastatic breast cancer. Knockdown of COBRA1 leads to elevated hormone-dependent transcription and accelerated cell proliferation in vitro. To further investigate the biological function of COBRA1, we compared tumor growth of control and COBRA1 knockdown human breast cancer cells in a xenograft mouse model. In contrast to tumors from the control cells whose growth was strictly estrogen-dependent, tumors from COBRA1-depleted cells achieved sustained growth even in the absence of exogenously added estrogen. This result suggests that depletion of COBRA1 either allows hormone-independent cell proliferation or sensitizes cells to grow under extremely low levels of estrogen. In a complementary approach, a Cre-lox system was used to delete mouse Cobra1 in whole body or in mammary gland. Mouse embryos deficient in Cobra1 do not develop beyond E5.5; and mammary gland-specific Cobra1 knockout mice exhibit severe defects in alveologenesis and lactogenesis. The molecular basis for the Cobra1-associated developmental defects and the possible impact of Cobra1 deletion on mammary tumorigenesis will be discussed. By linking regulation of transcription elongation with mammary gland-specific functions, our work establishes a novel paradigm for gene regulation in mammary gland biology and breast cancer research.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6013.
Inhibition of E-cadherin is associated with down-regulation of members of the miR-200 family but not with promoter methylation in human breast cancer cell lines.
Authors: Tryndyak VP , Beland FA , Pogribny IP 
Published: December 2010

Abstract
Abstract #6017
Background: Increasing evidence indicates the fundamental role of epithelial to mesenchymal transition (EMT) in breast cancer progression and this is viewed as an essential early step in tumor cell invasion and metastasis. One of the pivotal events of EMT is down-regulation of E-cadherin. Recent findings have demonstrated the importance of the miR-200 microRNA family in the regulation of E-cadherin and EMT. In view of these findings, we examined the relationship between expression of members of the miR-200 family and status of E-cadherin levels in various human breast cancer cell lines.&#x2028; Materials and Methods: Using quantitative real-time PCR analysis, we analyzed the expression of miR-200b, miR-200c, and miR-141 in 15 human breast cancer cell lines. Additionally, we measured the level of ZEB1, ZEB2, and E-cadherin proteins using Western blot analysis and E-cadherin promoter methylation by methylation-specific PCR.&#x2028; Results: We found a substantial down-regulation of miR-200b, miR-200c, and miR-141 in the breast cancer cell lines. The extent of down-regulation was correlated with metastatic potential of cells. The down-regulation of members of the miR-200 family was associated with up-regulation of ZEB1 and ZEB2, transcriptional repressors of E-cadherin, and a subsequent decrease in the E-cadherin levels. More importantly, inhibition of E-cadherin expression was not due to its promoter hypermethylation. Treatment of breast cancer cells with demethylating agent 5-aza-2'-deoxycytidine resulted in over-expression of miR-200b and miR-200c, increase of the level of E-cadherin, and diminished metastatic properties of cancer cells.Discussion: Previous studies have revealed the important role of promoter methylation-related inhibition of E-cadherin in EMT in human breast cancer. However, the transcriptional silencing of E-cadherin is not always related to promoter hypermethylation, which indicates the existence of other mechanisms in E-cadherin down-regulation. In the present study, we demonstrated the crucial role of members of the miR-200 family in up-regulation of ZEB1 and ZEB2 proteins leading to subsequent E-cadherin down-regulation in human breast cancer cell lines. The extent of down-regulation of the miR-200 family was dependent of cancer stage and was associated with metastatic potential of cancer cell lines. This suggests that expression of miR-200 may be a powerful diagnostic marker determining breast cancer stage and cancer invasive phenotype. More importantly, the results indicate the great potential for reversing the invasive phenotype of cancer cells by up-regulation of miR-200 microRNAs.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6017.
The development of a potent, multifunctional gene delivery vector driven by the cancer-selective mucin-1 promoter to detect and treat breast cancer metastasis.
Authors: Huyn ST , Burton J , Sato M , Wu L 
Published: December 2010

Abstract
Abstract #6022
With breast cancer, early detection and proper staging are critical, influencing both the treatment regimen and therapeutic outcome for a patient. Improvements in these areas will play a profound role in reducing mortality due to this disease. We therefore aim to develop a targeted adenoviral based gene therapy vector that can be used in the detection and staging of metastatic breast cancer. We did this through application of the two-step transcriptional amplification system (TSTA). This system was developed in our lab, and has shown the ability to greatly augment the activity of weak promoters, while still maintaining tissue specificity.&#x2028; We incorporated the tumor specific promoter Mucin1 into the TSTA system to successfully target breast tumor models. Studies carried out in vitro have demonstrated that this MUC1 TSTA vector is able to achieve efficiency of up to 250 fold over basal promoter levels, without loss of specificity. Moreover, when incorporated into an adenoviral vector to express firefly luciferase (AdMUC1-TSTA-fl), it exhibits higher reporter gene expression than a AdCMV-fl virus at the same multiplicity of infection (MOI).&#x2028; Biodistribution studies have shown that, depending upon the initial route of administration, this system holds great potential for use in the detection of lymph node metastais, as well as distant metastases. This vector has shown low off target expression following intravenous injection into non-tumor bearing mice. Through use of in vivo xenograft models of breast cancer, we have shown the ability to target and detect both lymph node metastais, as well as liver metastasis using our AdMUC1 TSTA-fl reporter virus in combination with in vivo optical imaging. Based on these results, we believe that this system holds strong promise for clinical application.&#x2028; A critical aspect of this project will be the incorporation of cytotoxic genes for therapeutic studies. At the same time, the ability to express imaging reporter genes for bioluminescent imaging or PET (positron emission tomography) is highly desirable, allowing for efficient, non-invasive monitoring of pharmacokinetics of transgene expression in real time. To address this issue, we developed a MUC-1 driven TSTA amplification scheme able to simultaneously express two separate transgenes, the firefly luciferase and the herpes simplex virus thymidine kinase (HSV-tk sr39tk) gene. This bi-directional reporter TSTA construct has shown strong efficiency, and specificity, and is currently being evaluated for use in therapeutic application of breast tumors in vivo. This approach holds great promise for the treatment and diagnosis of metastatic breast cancer.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6022.
TOP2A mRNA expression in HER2 negative breast cancer.
Authors: Gennari A , Sormani M , Pfeffer U , Morandi L , Mustacchi G , Danesi R , Mirisola V , Bruzzi P 
Published: December 2010

Abstract
Abstract #6036
Background Recent meta-analyses on the interaction between HER2 status and efficacy of adjuvant anthracyclines suggest that patients with HER2 negative tumors derive no added benefits from anthracycline administration. Since topoisomerase IIa is a known target of the anthracyclines, it's expression has been proposed as a more accurate and biologically related predictive factor of anthracycline responsiveness. Additional evidence suggests that TOP2A gene amplification occurs only in HER2 amplified tumors, whereas it is rare among HER2 negative patients. The aim of the present study was to address the regulation of TOP2A expression, at the level of mRNA, in HER2 negative disease. Methods We used two previously published Affymetrix gene expression datasets: GSE 1456 (159 patients) and GSE 2494 (249 patients). Microarray data preprocessing was carried out using Bioconductor software (gcrma procedure). Expression of HER2 and TOP2A were evaluated extracting the Affy probes “210930_s_at” and ”216836_s_at” (for HER2) and the Affy probe "201292_at” (for TOP2A); overexpressed samples were defined those with expression values over the 75th percentile of the whole sample of patients. The distribution of TOP2A mRNA overexpression according to molecular subtype was evaluated in the GSE 1456 dataset.&#x2028; Results: Overall, 348 out of 408 patients were HER2 negative. TOP2A mRNA overexpression was detected in 65 out of 348 HER2 negative tumors (18,7%). In the GSE 1456 dataset TOP2A mRNA overexpression was detected in 48% of basal like tumors, 42% of Luminal B and 21% of Luminal A. Among HER2 positive tumors, TOP2A mRNA overexpression was detected in 40%. mRNA TOP2A overexpression was present in 27% of the ERBB2 and in 80% of the Luminal B (HER2 positive) molecular subtype.&#x2028; Conclusions: TOP2A overexpression, at the level of mRNA, is present in the HER2 negative population and it is distributed in all molecular subtypes, especially among the Basal like and Luminal B subtypes. We are currently evaluating the interaction between TOP2A mRNA expression and efficacy of adjuvant anthracyclines in a retrospective analysis of data including 200 early breast cancer patients.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6036.
Hot flashes are associated with CYP2D6 genotype in breast cancer survivors taking tamoxifen.
Authors: Madlensky L , Flatt SW , Natarajan L , Lawrence H , Nikoloff D , Fontecha M , Hao S , Hillman G , Johnson A , Parker BA , Pierce JP 
Published: December 2010

Abstract
Abstract #6045
Background: We have previously shown that participants in the Women's Healthy Eating and Living (WHEL) study comparison group who reported hot flashes after breast cancer treatment had more favorable disease-free survival than women who did not report hot flashes. However, this was not the case in the intervention group. The polymorphic CYP450 enzyme CYP2D6 catalyzes the conversion of tamoxifen (TAM) to one of its key active metabolites, endoxifen. Some studies have suggested that certain genetic variants of CYP2D6 are associated with a decreased likelihood of hot flashes, reduced endoxifen levels and an increased risk of disease recurrence in women receiving adjuvant TAM therapy. This analysis was performed to estimate the association between CYP2D6 genotype and hot flashes in early stage breast cancer survivors who took adjuvant TAM in the WHEL study.&#x2028; Methods: The WHEL study was a randomized trial of a dietary intervention in breast cancer survivors, who enrolled in the study within 4 years of diagnosis from 1995-2000. Participants self-reported TAM use, hot flash severity and menopausal status at study entry. Clinical characteristics (tumor stage, estrogen receptor status, chemotherapy) were extracted from medical records. Blood samples were obtained by venipuncture, separated and stored at -80 deg. DNA was extracted from stored buffy coat and analyzed using the Roche AmpliChip CYP450 Test. Women were classified according to their predicted CYP2D6 phenotype as Extensive (EM), Heterozygous Extensive (Het EM), Intermediate (IM), Poor (PM), or Ultrarapid (UM) Metabolizers.&#x2028; Results: Overall, 1434 WHEL participants had verified estrogen receptor-positive stage I or II breast cancers and reported taking TAM at baseline for at least 4 months. A total of 1411 women were successfully genotyped and their CYP2D6 phenotypes were classified as follows: 468 EM (33.2%); 665 Het EM(47.1%), 164 IM (11.6%), 86 PM (6.1%) and 28 UM (2.0%). In univariate analyses, there was a significant difference among CYP2D6 genotype in relation to hot flashes reported at baseline: 79.8% of EMs, 76.3% of Het EMs, 80.1% of IMs, 63.9% of PMs, and 75% of UMs reported hot flashes (χ2= 11.3, p=0.02). After controlling for age, menopausal status, and time since diagnosis, the PM group was half as likely to report hot flashes as the referent EM group (OR= 0.46; 95% CI= 0.28-0.78; p=0.003). Additional analyses of serum endoxifen levels and associations with disease outcome are underway.&#x2028; Conclusion: In the WHEL study, women who were classified as Poor Metabolizers of TAM, based on their CYP2D6 genotype, were half as likely as Extensive Metabolizers to report experiencing hot flashes while receiving adjuvant TAM treatment for early stage breast cancer.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6045.
Assays of circulating tumor cells and outcome in the triple-negative breast cancer trial TBCRC001.
Authors: Rugo HS , Carey LA , Mayer E , Marcom PK , Liu M , Ma C , Storniolo AM , Forero A , Esteva FJ , Wolff AC , Hobday T , Ferraro M , Davidson NE , Winer EP , Moore D , Scott J , Park JW 
Published: December 2010

Abstract
Abstract #6048
Introduction. Basal-like breast cancer (BBC) has low expression of ER, PR, and HER2, and is often called triple negative (TN) BrCa. TBCRC 001 is a multicenter randomized phase II study of cetuximab (C) alone or combined with carboplatin (P) in TN BrCa. Pts randomized to Arm 1 received C alone (400 mg/m2, then 250 mg/m2 weekly) with P (AUC 2, 3 of 4 weeks) added upon progression (PD). Pts on Arm 2 received C+P throughout. The primary endpoint was objective response. To explore markers of activity and response, we measured circulating tumor cells (CTCs) in pts on study and directly compared two methods of CTC enumeration; CellSearch (Veridex) and immunomagnetic enrichment followed by flow cytometry (IE/FC). A subset of samples were isolated for molecular profiling.&#x2028; Methods. Blood was obtained from consenting pts at baseline, 7 to 14 days after the first infusion, then monthly until the end of the study. CellSearch assay was performed as previously described using 7.5 cc blood in a CellSave tube and the CellSpotter analyzer, and the percent of CTCs staining for EGFR was also measured. For IE/FC, 20 ml of blood was subjected to IE using anti-EpCAM MAb-conjugated iron particles, followed by multiparameter FC for EpCAM, CD45, and nucleic acid content. CTC results were correlated by method, and to time on study treatment. In this preliminary analysis, the endpoint is time on study treatment (to progression/toxicity, TST).&#x2028; Results: Safety and efficacy data from arms 1 and 2 have been presented (Carey et al; SABCS 2007, ASCO 2008). Of 102 TN pts enrolled in this study, 65 had CTC measurements by both methods on at least one time point. CTC levels by the two assays were highly correlated at all time points. At baseline, Spearman's rank correlation coefficient was 0.67 (p&lt;0.0001). Using the cutoffs shown below, CTC by IE/FC or CellSearch at baseline and first follow-up correlated with TST. This relationship was observed in both arm 1 and 2.&#x2028; &#x2028; Conclusion: In this phase II trial of C or C+P in pts with TN metastatic BrCa, CTCs measured by two different techniques were highly correlated. CTC levels at baseline and 7-14 days predicted longer vs. shorter TST, suggesting that CTCs may be an early marker of response to targeted therapy. Additional molecular data on CTCs will be presented.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6048.
Circulating tumor cells and FDG-PET/CT: biological and functional methods for therapeutic monitoring in metastatic breast cancer.
Authors: Cristofanilli M , De Giorgi U , Rohren E , Ueno NT , Miller C , Doyle GV , Jackson S , Andreopoulou E , Handy BC , Reuben JM , Hortobagyi GN , Macapinlac HA , Fritsche HA , Valero V 
Published: December 2010

Abstract
Abstract #6052
Introduction: The combination of Computed Tomography (CT) and [18F] Fluorodeoxyglucose - Positron Emission Tomography (FDG-PET) scanning technologies provides a more complete picture of disease activity than CT alone. Circulating tumor cell (CTC) levels were shown to be more predictive than standard imaging (CT) when used to monitor disease progression in women with metastatic breast cancer (MBC). We performed a retrospective study to compare the ability of combined FDG-PET/CT to CTC to predict clinical outcomes in patients treated for MBC.&#x2028; Methods: One hundred and two MBC patients with either measurable or evaluable disease starting a new line of therapy had CTC counts and FDG-PET/CT scans done at baseline (BL) and at mid-therapy. CTC: 7.5mL of blood collected in CellSave tubes at both time points was assayed for CTC using the FDA approved CellSearch® System. Patients were categorized as having a favorable (&lt;5CTC) or unfavorable (≥5CTC) outcome. Imaging: non-contrast-enhanced CT images were acquired first, then FDG-PET/CT scans were performed after administering a mean dose of 555 MBq FDG (range 444-740 MBq) to fasting patients. CT, PET, and co-registered CT-PET images were reviewed independently by 2 radiologists. The highest recorded FDG uptake was semi-quantitatively analyzed and maximum standardized uptake value (SUV) calculated with response = SUV of &lt;50% in target lesions and no response = SUV of &gt;50%. Changes in CTC and SUV at mid-therapy were compared to progression free survival (PFS) and overall survival (OS).&#x2028; Results: CTC: 50% (51/102) patients had ≥5 CTC at baseline (BL). At mid-therapy (median 2.5 months from BL), 21/102 progressed (≥5CTC) with a median PFS of 2.8 months vs. 7.8 months for those with no progression (&lt;5CTC) (p&lt;0.0001). OS was 10.0 months for patients with ≥5CTC at mid-therapy vs. 29.6 months for those with &lt;5CTC (p&lt;0.0001). PET/CT: 48% (49/102) patients showed no response at mid-therapy with median OS = 17.4 months vs. 29.6 months for those responding (p=0.0020). Overall, there was approximately 75% concordance in predicting outcomes between imaging and CTC assay changes [Table 1]. The majority of patients with discordant results had more advanced aggressive disease, i.e., &gt;2nd line chemotherapy and triple-negative disease.&#x2028; &#x2028; Conclusion: ≥5 CTC and/or no response at FDG-PET/CT at mid-therapy accurately predicted significantly shorter OS.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6052.