bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract P5-03-02: Expression of RANK and RANK ligand (RANKL) in breast carcinoma and distinct breast epithelial cells from BRCA1 mutation carriers
Authors: Lindeman GJ , Visvader JE , Vaillant F , Mann GB , Soriano R , Branstetter D , Dougall WC 
Published: August 2014

Abstract
Background: Breast tumors in BRCA1 mutation carriers likely arise from luminal progenitor (LP) cells, previously shown to exhibit aberrant growth properties. Oophorectomy, and possibly tamoxifen, reduce breast cancer risk in BRCA1 carriers, potentially via inhibition of paracrine mediated signaling to stem/progenitor cells. RANKL is a major paracrine effector of progesterone's mitogenic action in mammary epithelium via its receptor RANK, and has a role in ovarian hormone-dependent activation of stem cells. Here we assessed RANK and RANKL expression in breast tumors and normal breast epithelial subtypes from women with mutations of BRCA1 (mBRCA1) or BRCA2 (mBRCA2).
Methods: RANK and RANKL expression in breast cancer or normal breast tissue samples with mBRCA1, mBRCA2 or wildtype (WT) BRCA1/2 were analyzed in formalin fixed paraffin embedded (FFPE) sections by IHC. kConFab and The Royal Melbourne Hospital Tissue Bank provided the samples used in this analysis; these samples were obtained with relevant IRB approval. RANK expression on normal breast epithelial cells was measured by flow cytometry. Antibodies against human RANK (N-1H8, N-2B10; Amgen) and RANKL (M366; Amgen) were used in both assays. Incidence of IHC staining was scored as a positive IHC signal of any intensity. The overall expression was generated using the H scoring method which is calculated as the staining intensity of the tumor (0-3) multiplied by the percentage of positively staining cells.
Results: Breast tumors from women with mBRCA1 had a higher incidence of RANK expression (68/162; 42%) compared with mBRCA2 (17/113; 15%) or WT (34/314; 11%) and higher overall H score (21.3) compared with mBRCA2 (8.0) or WT (3.4); RANKL expression did not vary greatly between groups: mBRCA1 (13/135; 10%), mBRCA2 (5/114; 4%), WT (23/212; 11%). In normal breast tissue, LP (Lin−EpCAM+CD49f+) and basal/stem cells (Lin−EpCAM−CD49fhi) expressed RANK on their surface. Similar expression patterns were seen in these epithelial subtypes from each BRCA1/2 genotype. Stromal cells (Lin−EpCAM−CD49f−) had minimal RANK expression.
Conclusions: RANK expression intensity and incidence scores are both enriched approximately 4-fold in breast tumors from BRCA1 carriers compared with other genotypes. Also, RANK is normally expressed in breast LP cells as well as the basal/stem cell containing population. Ongoing studies will assess functional regulation of LP or mammary stem cell activity by RANKL and determine if the RANKL/RANK signaling pathway affects the aberrant growth characteristics of these cells from BRCA1 mutation carriers.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-03-02.
Abstract P5-03-08: Mifepristone suppresses triple-negative breast cancer cell growth and cancer stem cell maintenance via down-regulating KLF5 expression
Authors: Liu R , Chen C 
Published: August 2014

Abstract
Triple-negative breast cancer (TNBC) is one of the most malignant breast cancers without effective therapeutic approaches currently. We previously reported that KLF5 is over-expressed in TNBC; KLF5 depletion significantly suppresses TNBC cell proliferation, survival and tumor growth. As a progesterone receptor antagonist, MIF has been reported to have anti-tumor activity in multiple hormone-dependent cancers, including luminal type breast cancers. Interestingly, we found that MIF is able to down-regulate KLF5 protein expression in TNBC cells, reduce cancer stem cell population and suppress cell growth of TNBC cells in vitro and in vivo. Similarly, we found KLF5 is also important for the maintenance of TNBC stem cell. We further demonstrated that MIF does not suppress KLF5 mRNA expression at all, but down-regulates KLF5 protein level via up-regulating miR-153 expression in TNBC cells. We found miR-153 mimics can down-regulate the KLF5 protein level in TNBC cells and decrease TNBC stem cell ratio similar to MIF does; consistently, miR-153 inhibitor rescued MIF-induced down-regulation of KLF5 protein expression and partially rescued the reduced cancer stem cell population by MIF treatment. Taken together, our findings suggest that MIF is able to inhibit TNBC growth and cancer stem cell population possibly via suppressing KLF5 expression; and our research may provide a new possible chemotherapeutic for the treatment of TNBC.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-03-08.
Abstract P5-03-12: Prognostic role of stem cell markers in triple-negative breast cancer (TNBC)
Authors: Song J , Apple S , Goodglick L , Mah VH , Kim SR , Alavi MT , Chia D , Deng X , Chang HR 
Published: August 2014

Abstract
Introduction: Triple-negative breast cancer (TNBC) is among the most aggressive types of breast cancer with frequent recurrence and death despite chemotherapy. Studies have shown that cancer stem cells play a key role in many of the drug resistant cancers including TNBC. In this study, we report the expressions of four stem cell markers in 158 TNBC tumors.
Design: Clinicopathological data were obtained from 158 triple negative breast cancers between 2002 and 2010. Tissue microarray was constructed and immunohistochemistry stains (IHC) for CD44 and CD24, CD 133 and ALDH1 were performed using the streptavidin-biotin method. Each set of TNBC consists of normal, ductal carcinoma in situ and invasive areas for assessment of IHC stains. Statistical analysis was done on the following parameters: Histological types, modified Bloom and Richardson grades, lymph-vascular invasion, lymph node status, tumor size, Ki67, presence of lymphocytic host response, age &gt;50 or &lt;50, BRCA status, prognosis (recurrence and death) and chemotherapeutic response. P values less than 0.05 were considered statistically significant.
Results: the mean age of this cohort of TNBC patients was 55 with 64% white, 13.2% black, 12.6% Asian/Pacific, 3.8% Hispanic/Latino and 1.9% other. The majority of these tumors (82.3%) were grade 3, 15.2% were grade 2, and less than 1% was grade 1. CD24, CD44 and CD133 expressions were significantly higher in TNBC than in normal breast tissues (p = 5.53 e-10, p = 1.14 e-11, p = 2.25 e-08 respectively). While both CD24 and CD133 expressions predicted poor survival (p = 0.073 and p = 0.043 respectively), neither was associated with recurrence. In contrast to CD24, CD44 and CD133 expressions, ALDH-1 expression was rare in TNBC and surrounding normal tissues. When expressed, ALDH-1 was associated with poor survival but cases were too few to reach significance. None of the four stem cell markers studied were associated with any of the conventional histopathologic features and BRCA1 or BRCA2 mutations.
Conclusions: Our study suggests that stem cell marker(s) may be prognostically important in TNBC patients. When it is fully characterized it may provide new insight in developing effective therapeutic strategies targeting stem cell related signaling pathways.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-03-12.
Abstract P5-03-13: ASPM as a link between mammary tissue architectures, Wnt signaling pathways, breast cancer stemness and aggressiveness
Authors: Tsai KK-C 
Published: August 2014

Abstract
Disruption of tissue microarchitectures represents an early step of tumorigenesis and the related molecular events may have important biological and clinical implications. Using a physiologically relevant model of tissue organization, we exploited the ubiquitous transcriptomic change associated with human glandular morphogenesis, thereby identifying a microcephaly-related gene ASPM that reciprocally links to mammary tissue architectures. We show that ASPM was functionally indispensible for the structural transformation of differentiated mammary acini and its depletion in breast carcinoma cells forced reversion of malignant tumor architectures. In vitro and in vivo functional assays, together with clinical correlative analysis, revealed that ASPM is an oncogenic factor that carries strong, independent and robust prognostic significance in breast cancer. Follow-on biochemical and functional studies demonstrated that ASPM serves as a scaffolding protein for upstream activators of beta-catenin, including notably dishevelled-2, whereby it regulates Wnt signaling pathways, cytoskeleton and cell locomotion. Interestingly, through its effect on the Wnt pathway activity, ASPM also critically regulate a subpopulation of breast cancer stem cells (CSCs) that exhibited high migratory potentials in vitro. Consistently, silencing of ASPM in breast CSCs attenuated the tumor growth and distant metastasis in mouse xenograft models of human breast cancer. Together, our results provide a novel mechanistic link between tissue architecture, Wnt signaling, breast cancer stemness and tumor aggressiveness (Supported in part by grants CA-101-PP-19 from National Health Research Institutes and DOH 102-TD-C-111-004 from Department of Health, Taiwan to K.K.T.).
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-03-13.
Abstract P5-03-14: Low dose ionising radiation effects in normal breast progenitor sub-populations
Authors: Kavanagh JN , Kissenpfennig A , Irwin GW , Prise KM 
Published: August 2014

Abstract
The human breast is a radiosensitive tissue and radiation exposure is proposed to contribute to mammary gland carcinogenesis through changes to stem and progenitor cells that result in aberrant proliferation, differentiation and genome instability. However, little is known about the low dose radiation response (LD IR) under conditions of relevance to environmental and occupational and medical imaging exposures.
This study utilises 2-D and 3-D breast models derived from two normal breast cell lines (MCF10A and HME1) and primary human mammary epithelial cells from reduction mammoplasty surgery, to investigate the mechanisms underpinning sensitivity of normal breast to LD IR and elucidate its role in breast cancer initiation and progression.
We have shown that DNA damage can be detected in both cell lines after doses &lt;50 mGy and that an increased level of DNA damage foci at 1 h post LD IR is observed in a subpopulation of cells.
Using antibodies to cell surface markers suggested to be putative breast stem cell markers, we have performed Fluoresence Activated Cell Sorting (FACS) to isolate subpopulations from the MCF10A cell line. CD49fhi, EpCAM-, MUC1- cells thought to be progenitor like cells were found to be more resistant to LD IR than the EpCAM+, MUC1+ population.
As the pathways that govern survival/proliferation of stem and progenitor cells versus differentiation are interconnected, we have investigated if radiation resistance is also correlated with changes to breast cell differentiation. It was observed that LD IR modulated breast cell lineage markers in 2D cultures of both cell lines.
We subsequently found that radiation induces a decrease in MUC1 mRNA expression levels which coincides with increased Lef1 expression. Lef1 has been shown to promote Mre11 expression thereby conferring elevated DNA repair and radiation resistance in tumour cells.
Based on our findings, we hypothesize that progenitor cell populations within normal breast cell lines may be more efficient at detecting DNA DSBs resulting from LD IR leading to a pro-survival response. We are currently investigating these effects in primary mammary epithelial cell samples, using FACS to isolate progenitor subpopulations.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-03-14.
Abstract P5-04-11: CDK11p58 inhibits estrogen receptor a positive breast cancer invasion via integrinb3 through repressing ERa signaling
Authors: Chi Y , Wang L , Wang L , Wei P , Wu J 
Published: August 2014

Abstract
Background: The sex steroid estrogen plays a major role in the development and progression of breast cancer. Estrogen promotes breast cancer proliferation through a number of established pathways. CDK11p58, a Ser/Thr kinase which belongs to Cell Division Cycle 2-like 1 (CDC2L1) subfamily, is associated with cell cycle progression, tumorigenesis and apoptotic signaling. In the previous study, we found that CDK11p58 interacted with estrogen receptor a (ERa) in breast tumor cells and repressed ERa transcriptional activity through promoting its ubiquitin/proteasome-mediated degradation. Here we sought to investigate the critical role of CDK11p58 in the carcinogenisis of breast cancer.
Methods and results: We measured the expression of CDK11p58 in 132 pairs of breast cancer tissues and adjacent tissues by IHC and qPCR. The mRNA and protein level of CDK11p58 were significant higher in breast cancer tissues than those in normal breast tissues. Interestingly, low expression of CDK11 was associated with lymph nodes metastasis in patients (P&lt;0.05). Using the ERa + cell lines ZR-75-30 and T47D, we found CDK11p58 could repress the migration and invasion of ERa positive breast cancer cells. We further demonstrated that mRNA of integrinb3 were dramatically repressed by CDK11p58 by the TaqMan® Metastasis Gene Expression Assays. The effect was CDK11p58 kinase activity dependent. Expression of integrinβ3 was highly related with ERa signaling. While overexpression ERa stimulates integrinβ3 expression, knockdown of ERa attenuates integrinβ3 expression. By the Dual-luciferase array and CHIP assay, we found estrogen response elements (ERE) indeed existed in integrinβ3 promoter. ERa bound to the ERE on the integrinβ3 promoter and increased its transcription.
Conclusions: Our findings provide mechanistic insights into how CDK11p58 regulated the expression of integrinβ3 to inhibit the cell invasion though repressing the signaling of ERa in a kinase activity dependent way. These data indicate that CDK11p58 is an antimetastasis gene product in breast cancer and regulation of integrinβ3 by CDK11p58 through ERa could be part of a signaling pathway that determines and explains breast cancer invasion and metastasis.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-04-11.
Abstract P5-05-04: Relationship between plasma estradiol levels and estrogen-regulated gene expressions in premenopausal estrogen receptor-positive breast cancers
Authors: Toyama T , Asano T , Sato S , Yoshimoto N , Endo Y , Hato Y , Takahashi S , Yamashita H 
Published: August 2014

Abstract
Background: Estrogen receptor (ER) and progesterone receptor (PgR) expression status in breast cancer are important factors in determining the use of adjuvant therapy. Plasma estradiol (E2) and progesterone vary markedly through the menstrual cycle. Recently, the levels of PgR expression were reported to be correlated with E2 at the time of surgery in Caucasian premenopausal breast cancer patients. Materials and methods: In this study, plasma E2 levels at surgery were examined for correlations with expressions of estrogen-regulated genes (ERGs), including PgR, and proliferation genes in 147 Japanese premenopausal ER-positive breast cancers. Plasma E2 and progesterone, FSH, and LH were measured on the day of surgery by ECLIA and mRNA expressions were analyzed for 4 ERGs (PgR, GREB1, TFF1, PDZK1), 2 progesterone-regulated (RANKL, cyclin D1) and 2 proliferation genes (MKI67, BIRC5) by RT-PCR using the TaqMan system. ER and PgR protein expression levels were estimated by immunohistochemistry. Results: Our results revealed that expressions of PgR mRNA and protein in breast cancer tissues were significantly correlated with plasma E2 levels at surgery (p = 0.005, p = 0.0165, respectively). Other ERGs were also significantly correlated with plasma E2 levels. However, there were no correlations between mRNA expressions of proliferation genes, MKI67 and BIRC5, and plasma E2 levels. Furthermore, mRNA expressions of the progesterone-regulated genes, RANKL and cyclin D1, were significantly correlated with PgR mRNA expression (p&lt;0.0001, p&lt;0.0001, respectively). Discussion: Significant correlations were seen in the expression of ERGs in Japanese ER-positive breast cancers according to the plasma E2 levels, which vary markedly through the menstrual cycle. Our results supported the previous report in Caucasian patients by other group. This variability may affect the interpretation of gene expression profiles incorporating ERGs such as the 21-gene recurrence score.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-05-04.
Abstract P5-05-05: Lower mitotic activity in BRCA1/2-associated primary breast cancers occurring after risk-reducing salpingo-oophorectomy
Authors: van Verschuer VMT , Heemskerk-Gerritsen BAM , van Deurzen CHM , Obdeijn IM , Tilanus-Linthorst MMA , Verhoef C , Schmidt MK , Koppert LB , Hooning MJ , Seynaeve C 
Published: August 2014

Abstract
Background Bilateral salpingo-oophorectomy reduces breast cancer (BC) risk by about 50% in BRCA1/2 mutation carriers when performed premenopausally. It has been hypothesized that growth activity of BCs originating after risk-reducing salpingo-oophorectomy (RRSO) is lower. We compared tumor characteristics and growth rates of BRCA1/2-associated primary BCs (PBCs) detected after RRSO with those of tumors originating without RRSO.
Methods From a cohort of 271 female BRCA1/2-associated patients with screen detected BC, 20 BRCA1/2 mutation carriers with PBC detected ≥12 months after RRSO were selected (RRSO group). Controls were 36 BRCA1/2 mutation carriers with PBC detected without RRSO (non-RRSO group) matched for age at PBC diagnosis (± 2.5 years) and for BRCA1 or BRCA2 mutation (intended matching ratio 1:2). Tumor growth rates, expressed as tumor volume doubling times (DT), were calculated. Pathology samples were revised for histological subtype, tumor differentiation grade, estrogen receptor (ER), progesterone receptor (PR) and HER2 status. Imaging examinations (magnetic resonance imaging (MRI), mammography) before and at BC diagnosis were revised.
Results Median age at PBC diagnosis was 52 years (range 35-67). MRI detected more BC than mammography in the RRSO-group as compared to the non-RRSO group (83% vs. 39%, P = 0.02). Tumor size at diagnosis was smaller in the RRSO group (11.0 mm vs. 17.0 mm, P = 0.01). Mitotic activity indexes (MAI) in the RRSO and non-RRSO group were 12 vs. 22 mitotic counts/2 mm2 (P = 0.02). No significant differences in differentiation grade, ER and HER2 status were found. PR-status was more often positive in the RRSO group without reaching statistical significance (38% vs. 13%, P = 0.07). Median DT in the RRSO group was 124 days (range 89-193) and 93 days (range 54-253) in the non-RRSO group (P = 0.47).
Conclusion BC occurring after RRSO in BRCA mutation carriers features a lower MAI, suggesting a less aggressive biological behavior. When confirmed in larger series, this may have consequences for BC screening protocols for BRCA1/2 mutation carriers after RRSO.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-05-05.
Abstract P5-05-08: Obesity suppresses estrogen receptor beta expression in breast cancer cells via a HER2-mediated pathway
Authors: Wiese MA , Bowers LW , Tekmal RR , Brenner AJ , Hursting SD , deGraffenried LA 
Published: August 2014

Abstract
Purpose: Increased levels of estrogen receptor beta (ERb) are correlated with an improved breast cancer prognosis. Our preliminary data suggests that obesity may decrease ERβ expression in certain breast cancer subtypes and may contribute to the more aggressive disease associated with obesity. This study aims to elucidate a potential mechanism(s) mediating this suppression.
Experimental Design: We utilized an in vitro model of obesity in which breast cancer cells were exposed to sera collected from postmenopausal breast cancer patients at the Cancer Therapy and Research Center at the University of Texas Health Science Center at San Antonio (UTHSCSA) and pooled by BMI category (obese (OB): ≥30 kg/m2; normal weight (NW): 18.5-24.9 kg/m2). Four human mammary tumor cell lines were used: SKBR3 (HER2 over-expressing, ERα negative), MCF-7 and ZR75 (ERα positive, HER2 negative) and MDA-MB-231 (triple negative), in addition to the mouse mammary tumor cell line, MMTV/neu (HER2 over-expressing). The effects of the sera on ERβ expression were assessed by qPCR. Protein expression levels were determined using Western blot analyses. Herceptin, a HER2 antagonist, was used to evaluate the role of HER2 in OB sera-induced ERβ modulation.
Results: OB sera exposure led to lower ERβ expression in SKBR3 and MMTV/neu cells in comparison to NW. Treatment of the SKBR3 cells with Herceptin at the time of OB sera exposure resulted in a three-fold increase in ERβ expression. In contrast, there was only a small increase in SKBR3 cell ERβ expression when Herceptin was added to NW sera, suggesting that the effects of the OB sera may be mediated by HER2 activity. In support of this hypothesis, exposure to OB versus NW sera did not modulate ERβ expression in MDA-MB-231, MCF-7 and ZR75 cells, which have very low levels of HER2. Lapatinib, another HER2 antagonist, will be used to inhibit HER2 signaling in MMTV/neu cells. On-going studies utilizing siRNA to the HER2 receptor aim to elucidate the HER2-regulated pathways contributing to the ERβ suppressing effects of OB sera in SKBR3 cells.
Conclusion: Based on our preliminary data, we hypothesize that obesity suppresses ERβ expression in breast cancer cells via a HER2-mediated pathway. Elucidation of the mechanism(s) mediating this effect could provide important insight into both the regulation of ERβ expression as well as how obesity promotes a more aggressive disease. Increased knowledge regarding the regulation of this effect may result in the identification of a new treatment target for the obese breast cancer patient population.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-05-08.