bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract P2-06-04: p300 acts as a tumor suppressor by inhibiting pro-metastatic microRNA pathways
Authors: Birnbaum M , Yuan H , Yue K , Bishopric NH 
Published: August 2014

Abstract
The histone acetyltransferase p300 is an important epigenetic factor known to regulate gene silencing, DNA repair, and cell cycle. Altered p300 expression is linked to cancerous phenotypes and has potential as both a biomarker and therapeutic target. Existing anti-cancer therapies such as histone deacetylase inhibitors (vorinostat, valproic acid, trichostatin A) are known to affect p300 levels and activity. Understanding how p300 affects cancerous and metastatic development is crucial to optimizing and advancing these treatments. However, whether p300 acts as a tumor suppressor or promoter is still controversial. To address this issue, we stably knocked down p300 levels in MCF-7, BT 474 and MDA MB 231 to 30-40% endogenous levels to directly examine p300's effects on tumorigenicity. Our experiments show loss of p300 significantly increased cell motility in the scratch assay (p&lt;0.05) and increased motility and invasion in a cell chamber migration chamber by 50% (p&lt;0.001). Xenograft tumors formed from KD-p300 shRNA MCF-7 cells were on average about three times larger at six weeks post implantation than that of non-silencing control NS-MCF-7 tumors. KD-p300 MCF-7 xenograft tumors demonstrate a more aggressive phenotype with increased vascularity.
To identify targets of p300 that might regulate its anti-tumor effect, we observed that miR-let-7c was downregulated in KD-p300 MCF-7 by 70% (p&lt;0.05). Consistent with this, the miR-let-7c target N-Ras was up regulated in KD-p300 MCF-7 cell lines and its xenograft tumors by three fold (p&lt;0.05). Knockdown of p300 of MCF-7 cells also displayed downregulated miR-141 and miR-200a and upregulated their known target, ZEB1, by 40% (p&lt;0.05). Gene expression profile assay showed that loss of p300 resulted in up regulation of ZEB1, laminin, collagen, IL-6, IFN, TGF-b, and components of the Wnt signaling pathway, which indicated a shift from epithelial to mesenchymal phenotype. Our data showed that loss of p300 was sufficient to induce a more invasive and potentially metastatic or EMT phenotype in breast cancer cells.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-06-04.
Abstract P2-06-05: Association of promoter methylation status of the FHIT gene and Fhit expression with HER2/neu status in breast cancer
Authors: Jeong YJ , Jang JI , Kim MS , Bong JG , Park SH , Oh HK 
Published: August 2014

Abstract
Purpose: Aberrant DNA methylation has been recognized to contribute to breast carcinogenesis, and promoter hypermethylation of many tumor suppressor genes has been correlated with decreased gene expression. The fragile histidine triad (FHIT) gene is a putative tumor suppressor gene in breast and other cancers, and loss of Fhit expression has been observed in breast cancers. The aim of this study was to evaluate the association between methylation of the FHIT gene and its expression in breast cancer, and to investigate whether methylation and expression of the FHIT gene would correlate with clinicopathological characteristics in relation to human epidermal growth factor receptor 2 (HER2) status.
Methods: Pyrosequencing of bisulfite treated DNA was performed to study the methylation status of the FHIT gene in 60 breast cancer samples from Korean women obtained at Daegu Catholic University Hospital. We examined the expression of FHIT using tissue microarrays by immunohistochemical staining. Association between the methylation status of the FHIT gene and its expression was analyzed, and the relationship between the FHIT expression and the clinicopathological characteristics of the patients was evaluated.
Results: FHIT methylation was detected in 96.7% and positive expression rate of Fhit was 87.3% of the patients. The mean methylation level of the FHIT gene was associated with intratumoral inflammation. Methylation level of the FHIT gene had no significant differences according to molecular subtypes. Loss of Fhit expression was associated with large tumor size, basal-like subtype and positive expression of EGFR. In HER2-negative breast cancers, loss of Fhit expression was significantly associated with tumor size, estrogen receptor status and Ki-67 proliferation index. There was no significant correlation between methylation of the FHIT gene and its expression in this study.
Conslusion: Our study revealed that loss of Fhit expression in breast cancer is associated with poor prognostic features, although there is no significance association between the FHIT gene methylation and Fhit expression. We found that in HER2-negatvie breast cancers, loss of Fhit expression was associated with poor prognostic features. These results support the possibility of potential complementation between HER2 and the Fhit pathway. The clinical significance of our findings needs to be further evaluated in larger cohorts with longer follow-up.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-06-05.
Abstract P2-09-12: Withaferin A-mediated inhibition of breast carcinoma involves concomitant activation of CHOP and Elk1 via ERK/ribosomal S6 kinase (RSK) signaling axis regulating death receptor 5 expression
Authors: Sharma D , Nagalingam A , Kuppusamy P , Saxena N 
Published: August 2014

Abstract
Introduction: Despite significant progress towards screening efforts and targeted therapies, breast cancer is still a leading cause of cancer-related mortality among women. Novel therapeutic strategies are clearly needed for effective targeting of breast cancer. Natural products continue to generate interest for identification of potential chemopreventive and therapeutic agents. Withaferin A (WFA) is a bioactive small molecule that has been proposed as a new-generation molecule capable of eliciting growth inhibitory effect on cancer cells. The molecular mechanisms by which WFA mediates inhibition of breast cancer remain elusive. The present study was designed to systematically elucidate the underlying mechanisms by which WFA inhibits growth and metastatic potential of breast cancer cells.
Methods: Efficacy of WFA treatment on cell growth was evaluated by using clonogenicity, and anchorage–independent growth. Western blot and immunofluorescence analysis were used to examine activation of ERK/RSK (extracellular signal-regulated kinase/ ribosomal S6 kinase) and downstream signaling axes. Functional importance of ERK/RSK and CHOP (C/EBP homologous protein) in the biologic effects of WFA was examined by using overexpression, phospho-deficient constructs and specific inhibitors. Finally, mouse xenografts, immunohistochemical, RT-PCR and western blot analysis of tumors were used.
Results: Analysis of the underlying molecular mechanisms revealed that WFA treatment induced phosphorylation of RSK2 in an ERK-dependent manner. Further, WFA-induced ERK/RSK signaling resulted in concomitant upregulation of CHOP and Elk-1(ETS-like transcription factor 1). By using ERK1/2 siRNA and FMK-MEA inhibitor, we found that ERK/RSK signaling axis is required for WFA-mediated modulation of CHOP and Elk-1. Intriguingly, we discovered that WFA triggers the nuclear translocation of CHOP and Elk1 resulting in transcriptional upregulation of Death Receptor protein (DR5). CHOP and Elk1 overexpression potentiated while phospho-deficient Elk-1 inhibited WFA-induced DR5 expression exhibiting that CHOP/Elk-1 cooperatively regulate DR5 expression. Furthermore, using nontoxic doses of WFA, we showed that WFA treatment effectively inhibited breast tumorigenesis in vivo. Analysis of WFA-treated breast tumors showed increased activation of ERK/RSK axis and DR5 along with higher nuclear accumulation of CHOP and Elk-1.
Conclusion: These data provided first in vitro and in vivo evidence of the integral role of a previously unrecognized crosstalk between WFA and ERK/RSK and CHOP/Elk-1 axes in breast tumor growth inhibition. WFA treatment could potentially be a rational therapeutic strategy for breast carcinoma.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-09-12.
Abstract P2-09-18: Identification of synergistic drug combination for HER2 positive breast cancer
Authors: Chalugun P , Shim JS , Liu JO 
Published: August 2014

Abstract
Breast cancer is one of the leading causes of death worldwide. 25-30% of breast cancer has HER2 gene amplification, which tend to give rise to poorly-differentiated and high grade tumor with a higher likelihood of spreading. Currently, trastuzumab and lapatinib are the only two FDA-approved treatments that target HER2 positive breast cancer. However, resistance to both drugs is already reported. Since breast cancer is considered to be one of genetic diseases caused by multiple gene aberrations, we used synergistic drug combination as a strategy to overcome these growth signaling pathway abnormalities. To identify new drug combination with lapatinib, we performed a cell-based screen against a library of clinical drugs of 3,200 compounds. Triptolide, a traditional Chinese medicine emerged from the screen with strong synergistic effect with lapatinib in HER2 positive breast cancer cells. This effect was specific to HER2 positive breast cancer. The whole HER2 signaling pathway was inhibited and more cells underwent apoptosis. Besides, both HER2 protein and mRNA levels were decreased in cells treated with the combination. This drug combination was also effective in breast cancer xenograft models of mice. Together, these findings suggest that both triptolide and lapatinib can be used as a promising drug combination for HER2 positive breast cancer.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-09-18.
Abstract P2-10-02: PD-L1 protein expression is a prognostic biomarker in breast cancer
Authors: Wimberly H , Schalper K , Chen L , Velcheti V , Pusztai L , Rimm D 
Published: August 2014

Abstract
BACKGROUND: Programmed death ligand 1 (PD-L1) and its receptor, PD1, are involved in limiting immune response. In the context of cancer, tumor cells expressing PD-L1 can suppress the immune response of PD1-expressing tumor infiltrating lymphocytes (TILs). Disruption of this pathway with antibodies to either the ligand or the receptor has shown promise in the treatment of non small cell lung cancer, melanoma and renal cell cancer. Here we investigate the pathway in breast cancer.
METHODS: PD-L1 protein expression was assessed on two Yale TMA breast cancer cohorts with two-fold redundancy by quantitative immunofluorescence (QIF) using AQUA technology. Cohort 1 (YTMA201) consists of 400 patients with has extensive follow-up and adjuvant treatment information. Cohort 2 (YTMA128) consists of 245 patients with limited follow-up and no treatment information. The PD-L1 antibody (Lieping Chen, clone 5H1) has been previously validated for specificity and reproducibility using transfected cell models. TILs were assessed by a pathologist for each cohort using a score from 0-3 based on the amount of TILs within the spot. AQUA scores for PD-L1 were used as a continuous variable and also cut at the median for outcome analysis.
RESULTS: PD-L1 protein is positively correlated with TILs (p&lt;0.0001 on cohort 1 and p = 0.0072 on cohort 2) and inversely correlated with estrogen receptor status (p&lt;0.0001 on cohort 1 and p = 0.0188 on cohort 2) on both breast cancer cohorts examined (total n = 594). On cohort 1, PD-L1 protein expression is a marker of good prognosis as a continuous variable (p = 0.0271) as well as when cut at the median (p = 0.0151), particularly in the estrogen receptor positive subset of patients.
CONCLUSIONS: PD-L1 expression in breast cancer is positively associated with TILs and inversely associated with estrogen receptor status on two independent breast cancer cohorts. PD-L1 protein expression shows prognostic value in breast cancer patients, particularly the ER positive subset of patients. Further assessment of PD-1 axis marker expression may be valuable as the associated therapeutics are being tested in breast cancer patients.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-10-02.
Abstract P2-10-05: Lymphatic and pro-inflammatory candidate gene variations and breast-cancer related lymphedema
Authors: Fu MR , Axelrod D , Guth AA , Goldberg J , Li X , Cartwright F , Haber J , Conley Y 
Published: August 2014

Abstract
Background
Traditionally, breast cancer-related lymphedema is considered to be mainly due to the mechanical injury from cancer surgery. Recent research identified that inflammation-infection may be one of the important predictors for breast cancer-related lymphedema. This pilot study aimed to explore the associations between lymphatic and pro-inflammatory candidate gene variations and lymphedema following breast cancer treatment.
Methods
A prospective, longitudinal, repeated-measure, and comparative design was used to recruit a sample of 178 breast cancer survivors. To ensure the accuracy of lymphedema phenotype, lymphedema was classified into two phenotypes: lymphedema of arm and breast. Arm lymphedema refers to swelling in the affected arm that must have been validated by infra-red perometer-S350 and a bioimpedance device. Breast lymphedema refers to swelling in the affected breast validated by self-report and an observational scale since no objective measure is available.
Saliva samples were collected for DNA extraction from all the 178 participants. Candidate Gene Association Research Method was used to examine the eight genes known for inflammation and lymphatic specific growth factors, including candidate genes for inflammation, cytokines (IL1A, IL6, IL8, IL10, IL13) and PTGS2 (COX2), and lymphatic specific growth factors [VEGF-C & D]. Descriptive statistics, Chi-Squared tests for contingency tables and one-way analysis of variance for continuous variables were used to compare the genotypes for each of these genes in patients with and without lymphedema. Odds ratios of developing lymphedema are estimated.
Results
Among 178 survivors, 39 women were confirmed to have arm lymphedema by infra-red perometer-S350 and a bioimpedance device and 43 women had breast lymphedema. Five genes were significantly associated with breast cancer-related lymphedema. Specific single nucleic polymorphisms (SNPs) for lymphatic specific growth factors VEGF-C (rs4604006) and cytokine IL13 (rs1800925) were related to arm lymphedema. Specific SNPs of cytokine IL1A (rs1800587) and PTGS2 (COX2) (rs20417) were associated with breast lymphedema.
Conclusion
Our findings provided preliminary data on genetic susceptibility as a risk factor for breast cancer-related lymphedema. Findings of our study may serve as a preliminary foundation for a priori recognition of genetic risk that may facilitate lymphedema risk prediction prior to surgery and raises the potential for early intervention for a high-risk group.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-10-05.
Abstract P2-11-15: Immunohistochemical assessment of Ki67 with the antibodies SP6 and MIB1 - A comparison of prognostic information and reproducibility
Authors: Ekholm M , Beglerbegovic S , Grabau D , Lövgren K , Malmström P , Werner-Hartman L , Fernö M 
Published: August 2014

Abstract
Background
Proliferation is a key feature in breast cancer and also a clinical important factor for prognosis and treatment prediction. In the St Gallen Consensus of 2011, immunohistochemically analysed Ki67 was adopted as a surrogate marker to distinguish the “luminal A” from the “luminal B” subtype, in order to select patients with estrogen receptor positive disease expected to benefit from adjuvant chemotherapy. The mouse monoclonal antibody MIB1 is the generally accepted antibody for assessment of Ki67. However, other antibodies have been developed, e.g. the rabbit monoclonal antibody SP6. The assessment of Ki67 with MIB1 is unfortunately associated with a considerable lack of reproducibility. Rabbit monoclonal antibodies generally tend to have higher specificity without loss of sensitivity, compared to corresponding mouse monoclonal antibodies. SP6 has also been found to have reduced background staining compared to MIB1. According to these advantages, SP6 may be an alternative to MIB1 for routine staining of Ki67. Any methodological modification should, according to international recommendations, be compared against a clinically validated assay and demonstrate acceptable concordance before being introduced in clinical routine. The analysis of Ki67 with SP6 therefore needs to be evaluated and compared to MIB1 in a cohort of breast cancer patients with clinical follow-up.
Aims
To compare the antibodies SP6 and MIB1 for immunohistochemical assessment of Ki67 in primary breast cancer regarding prognostic strength and reproducibility of the evaluation.
Methods
Tissue microarray from a cohort of 237 premenopausal women with node-negative breast cancer was used for assessment of Ki67, with both SP6 and MIB1, by three different investigators. The 7th decile was applied for defining cut-off. Distant disease-free survival (DDFS) was used as endpoint and the follow-up was restricted to 5 years.
Results
Ninety per cent of the samples were classified into the same group, either high or low Ki67, irrespective of antibody used. Ki67 (high vs. low), analysed with both antibodies was associated to DDFS (34 events) in the univariable analyses (SP6: HR 2.6, 95% CI 1.3-5.2, p = 0.01 and MIB1: HR 2.8, 95% CI 1.4-5.7 p = 0.004) and showed borderline significance for DDFS in the multivariable analyses, also including HER2, age, and tumour size (SP6: HR 2.0, 95% CI 0.93-4.5, p = 0.074 and MIB1: HR 2.2, 95% CI 0.97-4.8, p = 0.058). The agreement between different assessors was somewhat higher for MIB1 than for SP6 (kappa-values 0.83-0.88 vs. 0.72-0.77).
Conclusions
SP6 was not superior to MIB1 and the two antibodies were comparable in the assessment of Ki67 for prognostic considerations in primary breast cancer.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-11-15.
Abstract P2-12-08: Genetic testing for breast cancer risk estimation: A cost-effectiveness analysis
Authors: Folse HJ , Dinh TA , Allman R 
Published: August 2014

Abstract
Genetic testing based on seven single-nucleotide polymorphisms (7SNP) can improve individualized estimates of lifetime risk of breast cancer relative to the Gail risk test alone, for the purpose of recommending MRI screening for women at high risk.
An individual-based, continuous-time simulation model of breast cancer and health care processes was used to simulate women in a virtual trial comparing the use of the 7SNP test to the Gail risk test alone to categorize patients as either low risk or high risk. Low risk patients received annual mammogram, while high risk patients received annual MRI.
Cancer incidence was based on Surveillance, Epidemiology, and End Results (SEER) data and validated to the Cancer Prevention Study II (CPS-II) Nutrition Cohort data set. Risk factors are drawn from the National Health and Nutrition Examination Survey (NHANES-4) and Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) data sets. Mammogram characteristics were derived from the Breast Cancer Surveillance Consortium (BCSC) dataset. Other parameters were derived from published literature.
The 7SNP test (vs Gail alone) saved 0.00734 quality-adjusted life-years (QALYs) per person at a cost of $1,971 per person ($268,386 per QALY). Limiting the 7SNP test to only those patients with a lifetime Gail risk of 16 - 28% resulted in a cost of $163,264 per QALY. These results were sensitive to the age at which the test is given, the discount rate, and the costs of the genetic test and MRI.
The cost-effectiveness of using the 7SNP test for patients with intermediate Gail risk is similar to that of other recommended strategies, including annual MRI for patients with a lifetime risk greater than 20% or BRCA1/2 mutations.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-12-08.
Abstract P2-12-09: Developing clinical sequencing assays at Einstein-Montefiore
Authors: Delio M , Patel K , Maslov A , Golden A , Greally J , Morrow B , Vijg J , Montagna C 
Published: August 2014

Abstract
The Department of Genetics in collaboration with a group of Montefiore's clinicians initiated the development of clinical sequencing tests with the final goal to incrementally build clinical sequencing assays to improve clinical care in the Bronx. The use of next generation sequencing is particularly relevant for cancer biology since the heterogeneity of cancer requires deep sequencing and high read depth, which prior to recent advances in technology was expensive and labor intensive.
We designed a custom gene panel for target sequencing using the Illumina HiSeq 2500 consisting of 650 genes for multiple disorders and diseases, including various cancers, in addition to rare and complex mendelian disorders. We sequenced 17 samples, including a tumor-normal breast cancer pair, where we identified a novel, pathogenic stop variant in the highly mutated TP53 tumor suppressor gene. In addition to our custom target panel, we sequenced this sample pair on two additional cancer panels (AmpliSeq Cancer Hotspot and the Comprehensive Cancer Panel using the Ion Torrent Technology) and performed Whole Exome Sequencing (WES) to ensure the sensitivity and specificity of our custom panel. This variant was detected on all platforms.
We found targeted capture high-throughput sequencing to be a cost effective, time sensitive and efficient approach in detecting pathogenic variants to aid diagnosis of individuals affected by cancer or mendelian disorders. We are currently receiving samples to sequence and plan to expand our program to various groups within the Einstein-Montefiore community. Using a personalized medicine approach we expect to detect biomarkers and prospective targets to develop an accurate and effective treatment plan for these individuals.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-12-09.