bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract P5-03-06: Progesterone Activates MAPK Pathway in Estrogen Induced Mammary Carcinogenesis
Authors: Boopalan T , Arumugam A , Delgado A , Parada J , Agullo P , Lakshmanaswamy R. 
Published: April 2011

Abstract
In women, breast cancer is the most prevailing endocrine-related malignancy. Epidemiological and experimental studies argue that estrogens are central to its etiology. Estrogen-induced carcinogenesis in ACI rats is highly relevant as a model for human breast cancer. These estrogen-induced cancers exhibit aneuploidy, as do invasive ductal mammary carcinomas in women. It has been demonstrated that ovary intact ACI rats given estrogen induced high incidence of mammary cancers while ovariectomized rats given the same dose of estrogen for the same length of time did not induce mammary cancers. Recently, we demonstrated that ovariectomized ACI rats given estrogen plus progesterone had a high incidence of mammary cancer. In this context, it is essential to understand the possible role of progesterone, if any, as the other main ovarian hormone in mammary carcinogenesis. Our goal was to determine the role of progesterone in mammary cancer development by using carcinogenesis induced solely by hormones in ACI rats. To achieve our goal, we designed the following experiment. Ovary intact and ovariectomized rats were used in this study. The groups (n=30) tested were as follows: 1) ovary intact control (no hormone treatment); 2) ovary intact rats given 30 mg estradiol; 3) ovary intact rats given 30 mg estradiol plus 30 mg mifepristone; 4) ovary intact rats given 30 mg progesterone; 5) ovariectomized control (no hormone treatment); 6) ovariectomized rats given 30 mg estrogen; and 7) ovariectomized rats given 30 mg estradiol plus 30 mg progesterone. Mammary glands were surgically excised and snap frozen in liquid nitrogen and stored at -80°C from a subset (n=4) of intact animals after four weeks of treatment and ovariectomized rats after twelve weeks of treatment. In rest of the animals mammary carcinogenesis was followed for nine months. As expected, estradiol induced mammary cancers in ovary intact rats and not in ovariectomized rats. Addition of progesterone to ovariectomized rats treated with estradiol induced high incidence of mammary cancer. Mifepristone treatment inhibited mammary carcinogenesis in ovary intact rats receiving estradiol. Pathway focused microarray analysis of mammary glands from the rats of different groups and treatment indicated alterations in apoptosis, MAPK and PI3K pathways. Estrogen plus progesterone treatment down regulated apoptotic genes such as Apaf1, Bad, Bax, Bid, Casp9 and up regulated Mapk3, Grb10, Itgb1, PrKca, Prkcz and Map4k1, Map2k1ip1, Mapk8ip2, Mapkapk5 in PI3K and MAPK pathways respectively when compared with estrogen alone treatment. We have observed differences both at transcriptional and translational levels. Our results clearly demonstrate the significance of progesterone in mammary carcinogenesis.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-03-06.
Abstract P5-04-03: Antibodies in Single Chain Format Against HER2/neu Antigen: Promising Agents for Breast Cancer Immunotherapy
Authors: Asgharpour M , Nejatollahi F , Jaberipour M. 
Published: April 2011

Abstract
Introduction: HER2/neu gene is overexpressed in 25-30% of breast cancers and is associated with increased metastatic potential and poor prognosis. Blocking the HER2/neu signaling has been the focus of most therapeutic approaches. Although monoclonal antibodies have shown some success in the inhibition of tumor growth, the HAMA reaction has limited the use of these agents. Human recombinant antibodies offer a potential alternative and provide valuable clinical agents for cancer immunotherapy. Our aim was to produce a source of specific single chain antibodies (scFv) against HER2/neu and assess their effects on cancer cell line. Materials and Methods: A phage antibody display library of single chain Fv (scFv) was panned against three HER2/neu epitopes and differentiated by BstN1 fingerprinting. The selected clones were screened for the ability to bind the HER2/neu positive cell line (SKBR-3) by flowcytometry. The cell line was treated with 3 specific scFvs and the expression of HER2/neu transcript was measured by real time PCR. The effects of the selected scFv antibodies on the cell line were evaluated by MTT assay. Results: one specific clone was isolated against each epitope. Flowcytometry assay showed that the clones bound to HER2/neu expressing cell line with intensity range 75-80%. Real time PCR results revealed that scFv-II, -III and combination of all the three scFvs downregulated HER2/neu gene expression (Fig 1). All the single chain types alone and in combination significantly inhibited the proliferation of the SKBR-3 cells in the MTT proliferation assay (Fig 2).
Conclusion: Herceptin (Trastuzumab) is a humanized antibody against HER2/neu which is approved by the FDA for treatment of HER2/neu positive breast cancers. Researches have shown multiple life-threatening side effects of Herceptin on the patients and also the overall objective response rate to herceptin is only 15-20%. Therefore there is a need for development of an alternative. The human origin, small size (20-30kDa), rapid blood clearance and good tumor penetration of human scFvs offer potential advantages for the use of these agents in cancer immunotherapy. Our results suggest that the highly specific anti-HER2/neu human scFvs that inhibit the proliferation of the breast cancer cell line could contribute in breast cancer immunotargeting approaches. In vivo assessment of the antibodies is under investigation to show the therapeutic effects of the selected scFvs.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-04-03.
Abstract P5-05-06: The Role of Sprouty 2 in HER2 Signaling in Breast Cancer; Decreased Expression Is Associated with Poor Outcome Including in Trastuzumab-Treated Patients
Authors: Faratian D , Sims AH , Mullen P , Kay C , Um I , Langdon SP , Harrison DJ. 
Published: April 2011

Abstract
Purpose: Resistance to trastuzumab is a frequent clinical problem, in part due to the overriding activation state of the MAPK/PI3K signaling pathways. Sprouty-family proteins are negative regulators of MAPK/PI3K signaling, but their role in HER2 signaling and resistance to therapy is unknown.
Experimental design: The association of Sprouty 2 gene expression with grade, HER2-status, and survival was investigated in a meta-analysis of 1107 breast tumors from six published microarray studies. Sprouty regulation in response to HER2/HER3 signaling was studied using qRT-PCR. Changes in expression of Spry2 and feedback inhibition on trastuzumab-resistance were studied using full-length/dominant-negative transfection or chemical inhibition in SKBr3 and BT474 cell lines in cell viability assays. Finally, expression of Spry2 was measured in a cohort of 122 patients treated with trastuzumab by quantitative fluorescence microscopy (AQUA).
Results: Low Spry2 gene expression was associated with high HER2 protein expression. Spry2 was regulated through HER2/HER3 signaling as a delayed early gene, an effect reversed by treatment with the dimerization inhibitor pertuzumab. Overexpression of Spry2 in the SKBr3 trastuzumab-resistant cell line resulted in synergistic inhibition of cell viability with trastuzumab. Restitution of feedback inhibition with the PI3K-inhibitor LY294002 had a similar effect. Low Spry2 expression was associated with increased risk of death (HR = 2.28, 95% CI 1.22 - 4.26; p=0.008) in trastuzumab-treated patients, including in multivariate analysis (Cox regression analysis, p=0.002).
Conclusions: These results suggest that combinations of negative regulators of growth factor signaling may be an effective therapeutic strategy in breast cancers with deficient feedback inhibition.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-06.
Abstract P5-05-10: EIA-Induced PP2A Expression Prevents β-Trcp Mediated FOXO3a Degradation and Enhances Chemosensitization by Inhibiting TAK1/IKK Signaling
Authors: Chang Y-W , Su J-L , Hung M-C. 
Published: April 2011

Abstract
Background: E1A gene therapy was tested in multiple clinical trials in breast, ovarian, and head and neck cancers. E1A can sensitize paclitaxel-induced cell death and combined paclitaxel chemotherapy and E1A gene therapy is currently tested in a clinical trial for ovarian cancer patients. It has been shown that resistance to paclitaxel occurs in cells expressing low level of FOXO3a. We found that Forkhead box O-class (FOXO) transcription factor FOXO3a is critical for E1A-mediated chemosensitization to paclitaxel. Knocked down FOXO3a expression dramatically abolished E1A-induced chemosensitization of paclitaxel. E1A stabilized FOXO3a by preventing ubiquitin-dependent proteolysis. The E3 ligase involved in stabilizing FOXO3a is β-transducin repeat-containing proteins (ßTrCP); ßTrCP binding to FOXO3a requires phosphorylation of FOXO3a at Ser644 by IKKβ. E1A reduces βTrCP-mediated ubiquitination of FOXO3a by inhibiting IKKβ activity. Further, inhibited IKKß activity is due to E1A-induced expression of PP2A, which binds to transforming growth factor β-activated kinase 1 (TAK1), thus inhibiting TAK1's activation of IKKβ. In this study, we found that E1A stabilizes FOXO3a which is required to sensitize paclitaxel-induced apoptosis. The stabilization is achieved by E1A-induced expression of PP2A/C, which inhibits the binding of TAK1 to IKKβ, therefore abolishing IKKß's function in phosphorylating FOXO3a and FOXO3a degradation. This result provides a rationale for the combination of E1A gene therapy and paclitaxel chemotherapy and may also shed light on design of targeted therapy.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-10.
Abstract P5-05-11: The Cellular Impact of HuR (Human (Hu) Antigen R) in Breast Cancer Cells on the Growth and Invasion In Vitro and the Expression of Cyclin D1 and MMP-9
Authors: Yuan Z , Sanders AJ , Ye L , Wang Y , Jiang WG. 
Published: April 2011

Abstract
Introduction: HuR, a ubiquitously expressed member of the Hu family, selectively binds and stabilizes ARE-containing mRNAs encoding proto-oncogenes, cell cycle regulators, cytokines and growth factors. The role of HuR and its cellular function in breast cancer remains unclear. In the present study, we aimed to provide new insights into the molecular and cellular implication of HuR in breast cancer.
Materials and methods. We first constructed a set of anti-HuR ribozyme transgenes that targeted human HuR. Breast cancer cells were transfected with the transgene, in order to establish new sublines with HuR expression knocked down. Cell growth and invasiveness were investigated using in vitro cell models. The expression of cyclin-D1 and MMP2 were determined using immunocytochemistry, Western blotting and polymerase chain reaction.
Results: Here, we show that MCF7 and MDA-MB-231 cells breast cancer cells stability transfected with a hammerhead ribozyme transgene specifically targeted to HuR (MCF7HuRKO and MDA-MB-231HuRKO) have a reduction in HuR expression both at mRNA and protein levels. Using these new sublines of breast cancer cells, the in vitro growth was evaluated. We showed that that HuR knockdown dramatically reduced cell growth in MCF7 cells (P &lt; 0.001) and to a lesser degree reduced that in MDA MB 231 cells. We further demonstrated that reduction of HuR in MDA MB 231 cells (MDA-MB-231HuRKO) resulted in a significant reduction of the in vitro invasiveness in MDA-MB-231 cells (P &lt; 0.001), although the same failed to occur to MCF-7 cells. Furthermore, we found that the decreased cell growth rate in MCF7 cells following HuR knockdown was seen together with a reduction in cyclin D1 transcript and protein levels. It was also interest to observe that the change in invasiveness in MDA-MB-231 cells after HuR knockdown was accompanied by a decrease in MMP-9 levels.
Conclusion: Our study shows that targeting HuR can influences breast cancer cell growth and invasion and suggests a role for HuR in vitro in enhancing breast cancer cell growth and invasion. These changes may be facilitated through changes in the level of cyclin D1 and MMP-9.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-11.
Abstract P5-06-03: Truncated ERBB2 Receptors: Diagnostic and Therapeutic Targets
Authors: Ward T , Iorns E , Singh S , Jegg A-M , Gallas M , Lippman M , Landgraf R , Pegram M. 
Published: April 2011

Abstract
Background:
Patients with ERBB2+ breast cancer have aggressive disease and poor prognoses. It is now apparent that many ERBB2+ tumors also express truncated ERBB2 receptors (t-ERBB2s), namely p110 and p95. Increased expression of t-ERBB2s by breast tumors correlates with increased nodal involvement, distant metastasis, and poor clinical outcome in patients. Because t-ERBB2s lack the epitope bound by trastuzumab, expression of high levels of these isoforms may designate patients who would be better treated with alternative anti-ERBB2 therapy such as lapatinib; unfortunately, there is currently no clinical method to distinguish full-length p185- versus t-ERBB2 in patient tumor samples. Materials and Methods:
Recombinant forms of p185-, p110- and p95-ERBB2 were constructed using standard cloning techniques and expressed in human mammary epithelial cells (HMLE) via retroviral vector. The expression and subcellular localization of constructs were confirmed by western blot analysis and confocal microscopy. The ability of p185- and t-ERBB2 constructs to transform HMLE cells was evaluated using soft agar assays, and the effects on migration and invasion of these cells were investigated by transwell assays. Finally, the in vivo tumor formation by p185- vs. t-ERBB2 expressing cells was evaluated in immunodeficient mice. Additionally, a novel proximity-based antibody-capture method method to discern full-length versus t-ERBB2 in patient tumor samples was assessed (COPIA). Block tumors and fine-needle aspirates from patient tumor samples were used for quantifying total and phosphorylated ERBB2 receptors.
Results and Discussion:
Recombinant p185- and t-ERBB2 constructs were stably expressed in HMLE cells, and were correctly targeted to the cell membrane, as shown by confocal immunofluorescence microscopy and immunoblot. Expression of p110 t-ERBB2 increased migration and invasion of HMLE cells compared to p185 ERBB2 (P&lt;0.0001), while p110, p95m and p185 ERBB2s were equally effective at enhancing anchorage-independent growth. In vivo, expression of p110 t-ERBB2 but not other isoforms led to increased tumor formation in mice compared to controls (P&lt;0.005). No apparent phenotypes were elicited by expression of intracellular t-ERBB2 isoforms. Using COPIA testing, t-ERBB2 isoforms were detected in strongly ERBB2- positive tumors (16 of 31 samples, 52%) and were phosphorylated in 10 of 31 (32%). As expected, t-ERBB2s were not detected in ERBB2-negative tumor samples.
Truncated ERBB2s, particularly p110, may be major pathogenic drivers in ERBB2+ cancers. These isoforms may accelerate disease progression by promoting invasion and metastasis, and likely mediate resistance to trastuzumab and other therapies. Thus, t-ERBB2s represent attractive novel targets for diagnosis and treatment of ERBB2+ breast cancers.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-03.
Abstract P5-06-06: The Safety and Tolerability of Panobinostat (LBH589) in Combination with Capecitabine +/− Lapatinib: A Phase I Study in HER2+ Breast Cancer
Authors: Peacock NW , Jones SF , Yardley DA , Bendell JC , Infante JR , Murphy PB , Burris HA. 
Published: April 2011

Abstract
Background: Panobinostat is a histone deacetylase (HDAC) inhibitor, for which in vitro studies have suggested activity in breast cancer lines. This phase I study was designed to assess the safety, tolerability, and efficacy of panobinostat in combination with lapatinib and capecitabine in 3 parts. Part 1, for which we have previously reported findings (Peacock et al, ASCO 2010), established the maximum tolerated dose (MTD) of panobinostat (30mg twice weekly) in combination with capecitabine (1000mg/m2 BID). Part 2, reported here, was designed to assess the QTc prolongation and overall toxicity of panobinostat in combination with lapatinib in patients with HER2+ breast cancer. Part 3 will assess the tolerability and efficacy of the triplet combination based on doses defined in Parts 1 and 2. Method: Patients aged ≥18 years with incurable, locally recurrent or metastatic HER2+ breast cancer were eligible. Additional eligibility criteria included: &lt; 3 prior treatments in the metastatic setting; ECOG PS 0-1; measurable disease by RECIST; no impairment of cardiac function; no prior treatment with HDAC inhibitors; informed consent. Lapatinib doses of 1000mg daily were administered with panobinostat doses of 15mg and 20mg three times weekly, following 1 week of 2 doses of panobinostat alone to assess QTc prolongation. Cycles were repeated every 21 days until disease progression or toxicity warranted drug discontinuation. Patients were reevaluated for response every 2 cycles.
Results: 5 female patients with HER2+ metastatic breast cancer were accrued to Part 2, with a median age of 66 years (range: 64 — 67); 80% of patients were ECOG PS 0. To date, patients have received 17 cycles of treatment (median 4 cycles), and 2 patients have stable disease (progression1, unevaluable 1, and too early to assess 1), with one patient remaining on treatment. There have been no dose-limiting toxicities. One patient was hospitalized for grade 3 peripheral neuropathy (unrelated). No grade 2/3/4 toxicities have occurred in &gt;1 patient; no QTc prolongation has been observed.
Conclusions: Our preliminary findings suggest that the combination of panobinostat and lapatinib is safe and tolerable. No QTc prolongation or cardiotoxicity has been observed. Part 3 will evaluate the triplet combination using the dosages established in Parts 1 and 2.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-06.
Abstract P5-06-08: Role of Androgen Receptor in Metastasis and Hormone Resistance of Estrogen Receptor Positive Breast Cancer
Authors: Ciupek A , Brusco L , Covington KR , Weigel NL , Lu Y , Mills G , Fuqua SAW. 
Published: April 2011

Abstract
Background: We have previously developed a novel model of estrogen receptor a (ERa)-positive breast cancer metastasis involving shRNA knockdown of Rho GDIa, an inhibitor of the GTP hydrolyzing enzymes of the Rho family.Also although it is known that androgen receptor (AR) is frequently expressed with ERa in breast tumors, and is generally accepted to be a favorable prognostic factor, its role in tumor progression and metastasis is unknown.
Materials and Methods: shRNA knock down was used to lower endogenous expression of Rho GDIa in ERa-positive MCF-7 cells. Metastasis of the knockdown cells was analyzed by injection into athymic mice followed by histological analysis of isolated tissues. Resistance to Tam was also analyzed in these cells by following tumor growth in injected mice treated with vehicle or Tam. To determine the involvement of specific pathways, western blot analysis was used to determine expression of components of the AR and ERa signaling pathways. Reverse phase protein arrays (RPPA) were also used to analyze global expression of phosphorylated proteins. Results: The MCF-7-Rho GDIa knockdown cells exhibited increased lung metastasis, and both primary and metastatic tumors were resistant to the inhibitory effects of Tam. AR protein was found to be overexpressed in the Rho GDIa knock down cells as well, as confirmed by both western blot and RPPA. AR RNA levels were not increased however, thus post-transcriptional modifications via the Rho pathway may be involved in its up-regulation. In addition, AR protein levels were modulated by estrogen treatment in the knockdown cells, suggesting a role for ER in its regulation.
Discussion: Given that AR was significantly overexpressed with the metastatic and resistant phenotype of these cells, its role in these processes is currently being explored with AR antagonists. AR may represent a clinical target for hormone therapy resistance and metastasis of ERa-positive breast cancer.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-06-08.
Abstract P5-08-01: Oncology Clinicians’ Knowledge, Attitudes and Practices Regarding Fertility Preservation
Authors: Goldfarb SB , Dickler MN , McCabe MS , Thom B , Jia X , Margolies A , Norton L , Hudis C , Basch E , Kelvin JF. 
Published: April 2011

Abstract
Background:
Many breast cancer survivors of child-bearing age wish to become parents after therapy and are concerned about the possibility of treatment-induced infertility. Educating patients about the effects of therapy on fertility, early menopause, and fertility preservation options prior to treatment may optimize a survivor's quality of life after treatment. It is unclear whether oncologists feel qualified to discuss fertility issues with their patients, and if not, what barriers prevent such discussions.
Methods:
An IRB approved cross-sectional survey was developed at Memorial Sloan-Kettering Cancer Center (MSKCC) in order for clinicians to self-evaluate their knowledge, attitudes, and behaviors regarding fertility preservation. Survey items were derived from existing surveys in the literature and input from a multidisciplinary committee. The web-based survey was systematically administered to all MSKCC ambulatory clinicians. Repeated email reminders were sent to optimize responses.
Results:
76 breast cancer clinicians at MSKCC and our regional network sites completed the survey between 2/9/09 and 2/25/09. Among respondents, there was widespread agreement (97% (70/72)) that patients should be informed of fertility preservation options, but fewer respondents (51% (37/72)) consistently discussed effects of treatment on fertility with their patients. Only 47% of clinicians (35/74) reported access to information about effects of treatment on fertility. Many physicians cited lack of training in fertility preservation, time constraints, and lack of referral information as barriers to educating patients. No significant difference existed in practice or knowledge between physicians who were practicing for ≤ 5 years vs ≥ 5 years.
Conclusions:
Physicians report that lack of education, resources and insufficient time hinder fertility preservation discussions with patients. Physicians might benefit from educational efforts regarding the effects of treatment on fertility and new fertility preservation techniques in order to effectively counsel their patients. Time limitations may be overcome by developing educational resources and collaborating with other clinical staff (e.g., nurses) to provide this vital information to patients. These findings are informing an institution-wide educational fertility program.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-08-01.