bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract P5-05-07: Promestriene effects on estrogen-sensitive breast cancer cell proliferation in vitro
Authors: Almodovar AJO , Litherland SA , Courtneidge S , Decker DA 
Published: August 2014

Abstract
Introduction: Promestriene (3-propyl ethyl, 17B-methyl estradiol) is a synthetic estrogen analogue with potential as a topical treatment for vaginal atrophy caused by estrogen deprivation. Topical Promestriene is minimally absorbed with chronic use and has been reported to significantly improve the symptoms of vaginal atrophy. However, to be considered for use for these symptoms in estrogen responsive post-menopausal breast cancer survivors on an aromatase inhibitor, Promestriene would need to show none of the cyto-proliferative properties of estrogen.
Methods: We conducted in vitro testing of estrogen responsive breast cancer cell line MCF-7, T-47D, and BT-474 for dose-dependent, estrogen-like functional responses to Promestriene in both estrogen-rich and estrogen-deprived conditions. As assay controls, cultures treated with Fulvestrant, Testosterone, Progesterone and Estradiol were analyzed in parallel.
Analysis: Dose dependent Estrogen-like responses in the cell lines were measured as 1) proliferation using flow cytometric analysis of CSFE fluorescence, 2) estrogen receptor expression by flow cytometry, and 3) GREB 1 RNA expression using TaqMan real time PCR quantitative analysis. All cultures were grown to quiescence in RPMI medium supplemented with 10% fetal calf serum. To induce estrogen deprivation, half of the cultures were then held 3 days in media pre-treated and containing anti-estrogen specific antibodies to sequester any residual estrogen from the culture. Data for each culture treatment were analyzed using linear regression analysis and compared using multifactorial or pairwise analyses to determine the significance of estrogen-like responses relative to the estradiol and untreated controls.
Results: In estrogen sufficient cultures, Promestriene exhibited no cell proliferative properties on MCF-7, BT-474, or T47-D tumor cells, even at very high concentrations. However, when estrogen in the media was sequestered and culture allowed to quiesce without estrogen receptor stimulation, low dose Promestriene effects on cell proliferation in MCF-7 estrogen responsive cells were not significantly different from low dose estradiol. Low dose Promestriene (2-10pg/ml), unlike comparable doses of estradiol, did not stimulate GREB1 expression in MCF-7 cells. In contrast, T-47D and BT-474 cell lines proliferated and increased GREB- expression in response Promestriene or Fulvestrant treatments.
Conclusions: The potential estrogen-like properties of Promestriene to stimulate the growth of estrogen receptor responsive breast cancer cell lines, especially in estrogen-deprived conditions, suggest caution when prescribed for vaginal atrophy in post-menopausal breast cancer survivors on an aromatase inhibitor. Its ability to activate growth and gene expression in ER- breast cancer cells warrants further study.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-05-07.
Abstract P5-05-09: Extract ERr731® does not mimic estrogen stimulated growth of MNU-induced breast cancer in ovariectomized Sprague-Dawley rats
Authors: Vollmer G , Möller FJ , Zierau O , Macejova D 
Published: August 2014

Abstract
Background: ERr731® (trade names Phyto-Strol® or femi-loges®), an extract isolated from the roots of the Siberian rhubarb (Rheum rhaponticum), is used as an alternative treatment option for menopausal complaints. In addition, it is regularly used for the treatment of oligomenorrhoea or amenorrhea. The efficacy of the extract on treatment of menopausal complaints was shown in clinical trials and follow-up studies. Although clinical trials did not show changes of mammographic density, we addressed the question whether ERr731 is capable to stimulate experimental breast cancer in an estrogen dependent manner.
Objective: The aim of the study was to assess whether or not the special extract ERr731® in a dosage relevant to human applications is capable to stimulate the growth of methyl-nitroso-urea (MNU) induced experimental breast cancer in ovariectomized Sprague-Dawley (SD) rats.
Experimentals: 32 female SD rats were obtained at the age of postnatal day (PND) 40. On PND 49 and 56 all animals received an intra peritoneal MNU injection of 50 mg/kg body weight (BW). 28 days after the second injection 24 animals were ovariectomized (OvEx) and randomly allocated to 3 experimental groups, 8 animals were SHAM operated and served as positive control. SHAM operated animals (first positive control) and one group of OvEX animals (negative control) were fed a (phyto)estrogen-free diet. A second positive control group of OvEx animals received the phytoestrogen-free diet supplemented with 10 mg/kg diet of estradiol-benzoate. To mimic human exposure, ERr731®, in a dose of 0.067 mg/kg BW/d was chosen which is equivalent to 2.5 mg of the extract/kg chow. The experiment was terminated 25 weeks after MNU injection. Tumor-specific parameters, as well as uterine wet weights (UWW) were assessed.
Results: Ovariectomy reduced the UWW &gt; 6fold. Estradiol-benzoate restored UWW almost completely, whereas ERr731® did not lead to an increase in UWW. Tumor incidence in estrogenized animals was 62.5% (5/8 animals) in the SHAM group and 50% (4/8 animals) in the estradiol-benzoate treated group. No tumors were detected in OvEx negative controls and OvEx animals supplemented with the human relevant dose of ERr731®. The total numbers of tumors were 17 in the group of SHAM operated animals and 5 in the estradiol-benzoate treatment group.
Conclusions: The human dose of ERr731® did neither exhibit estrogenic properties in the uterotrophic assay nor did it stimulate growth of MNU-induced breast cancers in OvEx SD rats, whereas estradiol supplementation at a low dose as well as estradiol levels in animals with a regular estrus cycle significantly promoted tumor growth. In this experimental model the used human dosage of ERr731® therefore appears safe regarding estrogen dependent growth stimulation of experimental MNU breast cancers.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-05-09.
Abstract P5-07-07: Prognostic value of mutant TP53 in basal breast cancer
Authors: Park JY , Choi JE , Lee JH , Son GT , Kang SH , Bae YK , Lee SJ 
Published: August 2014

Abstract
Backgrounds; p53 is a tumor suppressor gene that plays an important role in cell cycle control and apoptosis. In the breast cancer, mutant tumor protein (TP53) is expressed in approximately 30% and patients with mutant TP53 often tend to have poor response to chemotherapy and poor prognosis than those with normal TP53. But, according to a recent study, TP53 inactivation could cause to significant DNA damage and to eventual cell death by mitotic catastrophe. We investigated the expression frequency and prognostic value of mutant TP53 using tissue microarrays of 898 invasive breast cancers.
Patients and methods; From January 1995 to December 2005 at Yeungnam university hospital, patients who diagnosed with the primary invasive breast cancer and received operation were included in this study. Patients with bilateral breast cancer or distant metastasis at the time of diagnosis were excluded. According to the immunohistochemical results of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), Ki67, epidermal growth factor (EGFR) and cytokeratin (CK) 5/6, we classified patients into 6 subgroups, luminal A, luminal B1, B2, HER2-enriched, normal breast-like (triple negative nonbasal) and basal-like breast cancers. Immunohistochemical staining for TP53 was performed and we defined more than 10% stain of tumor cell as mutant TP53-positive. Distribution and prognostic significance of mutant TP53 in each subgroup was investigated.
Results; In 898 invasive breast cancers, mutant TP53 was identified in 33.5% (301/898). Each expression frequency of mutant TP53 was 10.9% (42/385) in luminal A, 32.1% (45/140) in luminal B1, 50.0% (34/68) in luminal B2, 63.7% (72/113) in HER2-enriched, 54.7% (35/64) in normal breast-like and 57.0% (73/128) in basal-like subtype, respectively. In whole breast cancer patients, patients with mutant TP53 tended to have poor overall survival (OS) and disease free survival (DFS). However, there was no statistical significance (p = 0.187 and p = 0.651). But, in 128 patients with basal-like breast cancer, mutant TP53 showed good prognosis in both OS and DFS (p = 0.003 and p = 0.021). In basal-like breast cancer, the expression of mutant TP53 had no association with other clinicopathologic factors such as tumor size, lymph node metastasis, histological grade, lymphovascular invasion etc. and 98.4% (126/128) patients received adjuvant chemotherapy. In multivariate anaylsis, expression of mutant TP53 was an independent prognostic factor for OS and DFS in basal-like breast cancers (p = 0.008 and p = 0.012).
Conclusions: This study showed that basal-like breast cancer with mutant TP53 has a good outcome in both OS and DFS. Further studies are needed to identify the action mechanism of mutant TP53.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-07-07.
Abstract P5-07-09: An aberrant spliced transcript of focal adhesion kinase expressed in human breast cancer
Authors: Yao L , Peng W , Li S , Shao Z 
Published: August 2014

Abstract
Background: Focal adhesion kinase is a tyrosine kinase that plays a critical role at focal adhesion sites in cell mobility and migration. The over-expression and mutation of FAK, which promotes tumor cell invasion and survival, frequently occurs in tumors, allowing FAK to be recognized as a cancer-relevant gene and a potential target for cancer treatment. The vast majority of evidence has revealed that the deregulation of alternative splicing processes often occurs in cancer-associated genes and leads to tumorigenesis.
Results: From 102 breast cancer tissue samples, we found six samples contained the 26 exon deletion FAK associated with a mutation at the 3192 bp site(CDS), but this 26 exon deletion FAK was not observed in the samples derived from 101 normal tissues. Interestingly, the 26 exon deletion FAK, which possesses the same kinase activity and biological function as wild-type FAK, is resistant to caspase-mediated cleavage and prevents breast cancer cells from apoptosis, promoting breast cancer cells survival.
Conclusion: Therefore, our study revealed that the aberrant splicing of the FAK gene may promote tumorigenesis, providing a new method for diagnosing breast cancer and a potentially important target for breast cancer treatment.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-07-09.
Abstract P5-08-01: Systematic interrogation of resistance to HER2-directed therapy identifies a survival pathway activated by PRKACA and PIM1
Authors: Moody SE , Schinzel AC , Singh S , Izzo F , Strickland MR , Luo LY , Thomas SR , Boehm JS , Kim SY , Wang ZC , Hahn WC 
Published: August 2014

Abstract
Amplification and/or overexpression of the receptor tyrosine kinase HER2 occurs in 20-25% of breast cancers, and is associated with poor prognosis. Targeting of HER2 with drugs such as trastuzumab, lapatinib, or pertuzumab has led to clinical benefit in patients with both metastatic and early-stage HER2-amplified breast cancer. However, resistance and disease progression always occurs in patients with metastatic disease, and many patients with early-stage breast cancer experience recurrences despite adjuvant anti-HER2 therapy. As such, understanding the mechanisms of resistance to anti-HER2 therapy has important clinical implications.
Recent studies have identified mutations in PIK3CA, the gene encoding the catalytic subunit of Phosphatidylinositol 3 kinase (PI3K), as one mechanism of resistance to trastuzumab. However, such mutations are present in only a fraction of trastuzumab-resistant breast cancers. We therefore sought to uncover novel mechanisms of resistance to anti-HER2 therapy through an unbiased screen for kinases and kinase-related molecules that are able to rescue HER2-amplified breast cancer cells from HER2 inhibition.
We utilized a library of nearly 600 lentivirally-delivered open reading frames (ORFs) to constitutively express the coding sequence of each molecule individually in HER2-amplified BT474 breast cancer cells in arrayed high-throughput format. We conducted two parallel screens for the ability of each of these molecules to rescue cells from anti-HER2 therapy: one in which we treated the cells with a lapatinib-like drug that inhibits the kinase activity of HER2 and EGFR, and one in which we lentivirally delivered a short hairpin RNA that suppresses expression of HER2.
We identified those ORFs that restored viability of BT474 cells to greater than two standard deviations above the median of all ORFs in each screen. Multiple members of the MAPK and PI3K signaling pathways scored in both screens, serving to validate the approach. In addition, the survival kinases PIM1 and PRKACA scored robustly. Mechanistic studies suggest that these kinases may confer resistance by restoring the phosphorylation of, and thereby inactivating, the pro-apoptotic protein BAD. Consistent with this finding, overexpression of Bcl-xl, which is inhibited by BAD, also conferred resistance to lapatinib in HER2-amplified breast cancer cells. Furthermore, pharmacological blockade of Bcl-xl and Bcl-2 with ABT-263 enhanced lapatinib-induced killing of HER2-amplified breast cancer cells in vitro, and partially abrogated the rescue conferred by both PRKACA and PIM1. These findings suggest that combined inhibition of HER2 and the anti-apoptotic molecules Bcl-xl and Bcl-2 could enhance tumor cell eradication and prevent or delay the emergence of resistant disease.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-08-01.
Abstract P5-08-14: Deregulated histone and cell cycle pathways are associated with anthracycline resistance in breast cancer
Authors: Braunstein M , Liao L , Lyttle N , Taylor KJ , Krzyzanowski P , Kalatskaya I , Stein L , Marcellus R , Al-Awar R , Bartlett JMS , Spears M 
Published: August 2014

Abstract
Drug resistance in breast cancer is the major obstacle to a successful outcome following chemotherapy treatment. While a well-recognized mechanism of resistance involves upregulation of multidrug resistance (MDR) genes, the complexity and hierarchy of other non-MDR driven pathways are still largely unknown. The aim of this study was to identify pathways contributing to anthracycline resistance using isogenic drug resistant breast cancer cell lines. We generated MDA-MB-231, MCF7, SKBR3 and ZR-75-1 epirubicin-resistant breast cancer cell lines, all of which were cross-resistant to doxorubicin and SN-38; only SKBR3 cell line was also resistant to taxanes. Epirubicin-resistant cells were morphologically different from native cells, and had alterations in apoptosis and cell cycle profile. Using gene expression and small inhibitor analyses we identified deregulation of histone H2A and H2B genes in all four cell lines. These genes contribute to several biological pathways, which include cell cycle, chromosomal maintenance, epigenetics, RNA polymerase and mitochondrial transcription, as well as post-translational protein modifications. Importantly, histone deacetylase and cell cycle/DNA damage small molecule inhibitors reversed resistance and were cytotoxic for all four epirubicin-resistant cell lines confirming that histone and cell cycle pathways are associated with epirubicin resistance. Our study has established a model system for investigating drug resistance in all four breast cancer subtypes and revealed key pathways that contribute to the molecular mechanisms of anthracycline resistance.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-08-14.
Abstract P5-11-06: Combination of insulin-like growth factor 1 receptor and PI3K/mTOR inhibition in triple-negative breast cancers
Authors: Liu T , Taliaferro-Smith LD , O'Regan R 
Published: August 2014

Abstract
Triple-negative (TN) breast cancers account for 15%-20% of all breast cancers with limited treatment options and poor prognosis. The poor outcomes seen with TN breast cancers (TNBCs) are in part due to a lack of viable therapeutic targets. Overexpression of insulin-like growth factor 1 receptors results in mammary tumorigenesis and is common in breast carcinomas. However, the use of IGF1R inhibitor alone has produced limited effects on TNBC cells inhibition. NVP-BEZ235 is a potent PI3K/mTOR dual inhibitor and has been shown to be effective in TNBC cell lines, especially for the mesenchymal-like and luminal-androgen receptor subtypes. Unlike rapamycin, which produces a feedback activation of Akt, NVP-BEZ235 alone successfully blocks the Akt activation and effectively inhibits the cells proliferation. Methods: In this study, we examined the effects of a selective IGF1R small molecule inhibitor picropodophyllin (PPP) in combination with NVP-BEZ235 on human MDA-MB-231, MDA-MB-468, HCC1806 and BT549 TNBC cell lines. SRB cell survival assays were performed following PPP or NVP-BEZ235 treatments alone and PPP in combination with NVP-BEZ235. Western blotting was used to detect expression and phosphorylation of down-stream signaling proteins and fluorescence-activated cell sorting (FACS) analysis to assess effects on apoptosis following treatments. Results: The combined IGF1R inhibition with PPP and PI3K/mTOR inhibition with NVP-BEZ235 resulted in significantly greater cytotoxicity than either PPP or NVP-BEZ235 alone in all four cell lines compared to single agent treatments. Notably, this difference was more pronounced at lower concentrations of both drugs (between 7.8 nM-62.5 nM). The combination of PPP and NVP-BEZ235 inhibitors also significantly increased apoptosis via induction of cleaved caspase-3 and suppressed the PI3K/Akt and MEK/ERK signaling cascades in these TNBC cell lines. Conclusion: These results suggest that the combined inhibition of IGF1R and PI3K/mTOR may be a more effective strategy than single inhibition for TNBC treatments and warrant further investigation in in vivo animal studies.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-11-06.
Abstract P5-13-14: Breast cancer in very young patient is a more aggressive entity independent from breast cancer subtype
Authors: Martínez MT , Peña-Chilet M , Perez-Fidalgo JA , Bosch A , Alonso E , Ferrer J , Burgues O , Bermejo B , Lluch A , Ribas G 
Published: August 2014

Abstract
BACKGROUND AND OBJECTIVES: Breast cancer in very young patients (&lt; 35 years) (BCVY) is an uncommon disease and when it occurs it usually has aggressive biological characteristics. Whether this effect is due to an overrepresentation of aggressive breast cancer subtypes in younger patients or not remains an issue of controversial. The objective of this study was to identify potential differences in the molecular and clinical features of breast carcinomas from patients &lt; = 35 years versus a cohort of older counterparts previously matched by breast cancer subtype.
METHODS: We performed a retrospective analysis of a prospectively maintained database that included 424 patients diagnosed with an invasive breast carcinoma from 1995 to 2012 at Hospital Clinico of Valencia. We selected 89 patients separated in two groups, the study group with very young women ≤ 35 years old and with no BRCA mutation or unknown and a second group with women older than 50 years. Data related to clinical and pathological features from both groups such as tumor size, nodal status, histological grade, Ki 67 labeling oestrogen and progesterone receptor and HER2 overexpression were obtained from medical records and we used the statistic model of chi-squared to compare the two groups.
RESULTS: Of the 89 patients, 43 patients ≤ 35 year were included in the study group (median age 31.4 years, standard deviation (SD): 3.82) and 46 patients &gt;50 years were included in the control group (median age 66.4 years, SD: 10.00). Ductal carcinoma was the most common histological subtype in both groups (88.4% of BCVY and 78.3% of the old woman). The majority of tumors were ER and PR positive in both groups, but younger women had a higher proportion of HER2 positive tumors, although the result was not significant. By subtype 57.4% of BCVY presented an immunohistochemical luminal subtype, compared to 71.7% in older patients. Triple negative and HER2 profiles were 11.6% and 34.8% in youngest versus 15.2% and 13.04% in older women respectively. No statistically significant differences were found in terms of breast cancer subtype (p = 0.279)). However, BCVY had a higher pathological grade (56% younger patients had grade IIII vs 26% in oldest, p = 0.002), higher proportion of Ki67 &gt;30% (32.5% of youngest versus 17.4% in older women, p = 0.008), larger tumors (16.3% of BCVY had size tumor &gt; 5 cm, versus 2.2% in controls, p&lt;0.0001) and more frequent nodal involvement (39.5% in young women vs 28.2% in oldest, p = 0.0264).
CONCLUSIONS: Patients diagnosed with breast cancer at ≤ 35 years present more aggressive tumors compared to older patients. These data suggest that BCVY is a distinct entity, further studies to confirm these findings are needed.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-13-14.
Abstract P6-01-01: Diet-induced obesity increases tumor growth and promotes angiogenesis in a murine model of breast cancer
Authors: Vona-Davis L , Coad J , Olfert M 
Published: August 2014

Abstract
Recent epidemiological studies provide strong evidence suggesting obesity is a risk factor in several cancers, including breast cancer. However, the exact molecular mechanisms by which obesity increases the risk of breast cancer are poorly understood. In this study, we evaluated the effect of diet-induced obesity on breast carcinogenesis in the MMTV-PyMT breast cancer model. Four-week old, female mice (n = 40) were randomized to high fat (HFD) or low fat (LFD) diets for 8 weeks. Body weights were obtained weekly and mice were imaged for mammary tumor volumes by 3D ultrasound. Tumor burden was collected during early and late stages, weighed and fixed for immunohistochemical staining. Blood and tissue from the liver, lung, and mesenteric fat were also collected. We also compared the basal VEGF protein expression in skeletal muscle, adipose tissue and mammary tumors from MMTV-PyMT mice and compared these levels against background nontransgenic FVB/N mice. Average tumor volumes and tumor burdens were markedly greater in the mice fed HFD than in LFD and showed an increased number of metastases to the lung by 2-fold. HFD increased mammary cell proliferation and elevated Chemokine (C-C motif) ligand 2 (CCL2) in the blood, tumor beds and adipose tissue. Histopathological analysis showed more tumor-associated macrophages and increased microvessel density with diet-induced obesity. Significantly more crown-like structures were evident in adipose tissue from obese mice at both early and late stage carcinoma. Adipose tissue of MMTV-PyMT mice exhibited greater VEGF protein expression compared to adipose tissue of control FVB mice, and greater VEGF protein compared to tumor VEGF expression. Our findings demonstrate that diet-induced obesity exacerbates breast cancer progression in MMTV-PyMT mice and suggests that high body adiposity caused by diet-induced changes promotes an inflammatory and angiogenic phenotype in breast cancer. NIH P20 RR016440, P30 R032138 and GM103488, and P20 RR016477.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-01-01.