bluuebunny/crossref_metadata_2025_split huggingface dataset:
P3-18-06: AEZS-131 – A Highly Selective ERK-Inhibitor: Characterization and Preclinical Testing in Triple Negative Breast Cancer (TNBC).
Authors: Engel JB , Seipelt I , Hönig A , Hahne JC , Teifel M 
Published: June 2012

Abstract
Introduction: Overexpression of MAPK has been detected in 34 % of TNBC and has been found to be associated with anthracycline resistance (1). AEZS-131 is a highly selective orally active ERK1/2-inhibitor, which has shown in vivo activity (first in class) in colon cancer. The following study explores mode of action and efficacy in models of TNBC.
Study design: AEZS-131 was tested in a kinase panel of 36 STK, 26 TK and 7 PIK to check for selectivity. Inhbition of Rsk-phosphorylation (cellular substrate of ERK) was evaluated by western blot analysis. Mode of action was explored by cell cycle FACS-analysis. Cleavage of PARP was explored by Western blot. Cytotoxic efficacy was evaluated in 5 TNBC, of which 2 had mutations in the MAPK signal transduction pathway lines, by MTT assay. Additionally it was explored if inhibition of classical apoptosis could abrogate the effect of AEZS-131.
Results: AEZS-131 selectively inhibited ERK with an IC50&lt;4nM. Phosphorylation of Rsk-1 the cellular substrate of ERK was inhibited with an IC 50 of 158 nM. AEZS-131 induced cell cycle arrest in G1 dose-dependently and cleavage of PARP. EC 50 was 0,739 μM for MDA-MB-231 (Ras-mutated), 0,137 μM for MDA-MB-435s (B-RAF mutated), 17,5 μM for MDA-MB-468 (PTEN loss), 25 μM for HCC 1806. HCC 1937 were not inhibited by the compound. Of note, inhibition of classical apoptosis did not alter the cytotoxic effect of the compound in MDA-MB-468 and HCC-1806 cells.
Conclusions: AZS-131 was shown to selectively inhibit ERK at low nM concentrations and to induce G1-arrest. Accordingly, the cytotoxic effect most pronounced in TNBC cell lines with mutations in the MAPK pathway. If classical apoptosis is inhibited, cytotoxic effects remain unchanged, suggesting that AEZS-131 can also induce nonclassical forms of programmed cell death. AEZS-131 should be further explored in TNBCs with overexpression of MAPK or mutations in the MAPK-pathway.
*Æterna Zentaris GmbH, Frankfurt/M, Germany.
(1): MAPK overexpression is associated with anthracycline resistance and increased risk for recurrence in patients with triple-negative breast cancer.
Eralp Y, Derin D, Ozluk Y, Yavuz E, Guney N, Saip P, Muslumanoglu M, Igci A, Kücücük S, Dincer M, Aydiner A, Topuz E.
Ann Oncol. 2008 Apr;19(4):669–74.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-18-06.
P4-01-15: Alteration of Y-box Binding Protein-1 Expression Modifies the Response to Endocrine Therapy in Estrogen Receptor Positive Breast Cancer.
Authors: Ito T , Kamijo S , Izumi H , Kohno K , Ito K-I 
Published: June 2012

Abstract
Y-box binding protein-1 (YB-1) plays an important role in tumor progression and drug resistance. This study examined whether YB-1 is involved in the alteration of response to endocrine therapy in ER-positive breast cancer cells. MCF7 cells that stably expressed YB-1 (MCF7-YB-1) and vector control cells (MCF7-vector) were established. These cells were used to analyze the expression of the factors related to the ER and growth factor receptor signaling pathways, response to the antiestrogens (tamoxifen and fulvestrant), and estrogen responsive element (ERE) activity. The effect of knocking down endogenous YB-1 expression was tested in wild-type MCF7 cells. In addition, the expression of the YB-1 and the factors related to the ER and growth factor receptor signaling pathways were evaluated in the clinical breast cancers treated with preoperative chemotherapy. The expression of HER2, AIB1, p-Erk and c-Myc were increased in the MCF7-YB-1 cells. In contrast, knocking down of YB-1 decreased the expression of these factors, but increased the expression of ERα in the wild-type MCF7 cells. Furthermore, sensitivity to antiestrogens was decreased in the MCF7-YB-1 in comparison to those in the MCF7-vector cells. In the MCF7-YB-1 cells, the expression levels of p-Erk and c-Myc were continuously upregulated when the cells were treated either with tamoxifen or fulvestrant. The ERE activity was decreased in the MCF7-YB-1 cells in comparison to the MCF7-vector cells, and the ERE activity of the MCF7-YB-1 cells was inhibited by fulvestrant at a lower concentration than that which inhibited the ERE activity of the MCF7-vector cells. In the ER-positive clinical breast cancers treated with preoperative chemotherapy, significantly more of the specimens that showed increased or positive nuclear YB-1 expression after the chemotherapy were positive for HER2 expression. These data suggest that alteration of YB-1 may modify the crosstalk between the ER pathway and HER2 pathway in ER-positive breast cancer cells, and consequently may alter the response to endocrine therapy in these cells.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-15.
P4-01-19: SRC-1 Expression Is a Prognostic Factor of Breast Cancer-Specific and Disease-Free Survival in Inflammatory Breast Cancer.
Authors: Arias-Pulido H , Ahmed RD , Chaher N , Vargas J , Joste N , Lomo L , Qualls C , Azziez S , Terki N , Bouzid K , Prossnitz E , Royce M 
Published: June 2012

Abstract
Background: Steroid receptor coactivator (SRC-1 to 3) proteins drive nuclear receptor transcriptional activity by modulating transcriptional processes such as chromatin modification, transcription initiation, chain elongation, and RNA splicing. In patients who display resistance to endocrine treatment, SRC-1 has been implicated in the conversion of tamoxifen anti-agonist activity to its agonist profile. SRC-1 expression is a prognostic of DFS in breast cancer, but its role in inflammatory breast cancer (IBC) remains unknown.
Materials and Methods: SRC-1 protein levels were measured by immunohistochemistry in 103 IBC and 11 normal, non-cancer related samples, diagnosed at the Centre Pierre & Marie Curie (Algiers, Algeria). Staining results were correlated with protein levels of ER, PR, and HER2, and clinico-pathological variables, breast cancer-specific (BCSS) and disease-free survival (DFS), and response to tamoxifen treatment.
Results: SRC-1 was positive in all normal breast tissue, as well as in 66% of IBC samples. SRC-1 positivity was associated with worse OS (P&lt;0.001) and DFS (P=0.004). SRC-1 expression correlated with worse BCSS (P=0.011), and marginally with DFS (P=0.046) in tamoxifen-treated patients, but strongly with DFS (P=0.007) in patients who received no endocrine therapy as indicated by Kaplan-Meier and log-Rank analyses. Multivariate analysis showed that SRC-1 (Hazard Ratios (HR): 5.2; 95%CI: 2.0−13.6; P&lt;0.001) and Her2 (HR: 3.1; 95%CI: 1.2−8.1; P=0.02) expression were independent prognostic markers of BCSS. SRC-1 (HR: 4.8; 95%CI: 1.9−12.2; P&lt;0.001), Her2 (HR: 2.4; 95%CI: 1.0−5.7; P=0.05), and hormone treatment (HR: 0.4; 95%CI: 0.2−0.8; P=0.01) were independent prognostic markers of DFS.
Discussion: Determining prognosis and predicting response to endocrine treatment is of paramount importance in the search for personalized treatment. SRC-1 expression predicts worse OS, DFS, and, similar to non-IBC, predicts DFS independently of endocrine therapy. This study highlights the importance of SRC-1 expression as a strong prognosticator of BCSS and disease recurrence in IBC patients. *Supported by an UICC ICRET Fellowship (ICR/09/043 to Dr. Chaher) and by New Mexico State IBC funding (New Mexico Senate Bill 532).
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-19.
P4-02-01: Bis(2-Ethylhexyl) Phthalate: A Potential Endocrine Disruptor Confer Letrozole Insensitivity and Induction of Aromatase Activity in Breast Cancer Cells.
Authors: Nair HB , Bhaskaran SS , Krishnegowda NK , Tekmal RR , VandeBerg JL 
Published: June 2012

Abstract
Exposure to endocrine disrupting compounds (EDC's) is an important determinant of mammary gland development and mammary tumor pathogenesis. The risk of breast cancer in adulthood is known to be influenced by environmental factors experienced as a fetus. Fetal exposure to dietary factors or certain pharmaceuticals and environmental chemicals that affect or mimic steroid hormones increase predisposition to breast cancer. The mechanisms by which EDC's alter epigenetic programming, differentiation and deregulation of ductal branching of mammary glands are poorly understood. A high ratio of estrogen receptor a (ERα) to ERβ has been recently found to be associated with poor prognosis and aggressive disease in breast cancer patients. Preliminary studies from our laboratory revealed that bis(2-ethylhexyl) phthalate (DEHP) is a possible EDC which induces cell proliferation in T47D, MCF7, MCF7/Aro breast cancer cells in vitro and confers insensitivity to letrozole, a third generation aromatase inhibitor. DEHP increased cell proliferation (MTT assay) in a dose dependent manner and was non toxic to T47D, MCF7 and MCF 7 Aro cells. 1, 10 and 100 nM concentrations of DEHP up regulated ERα and down regulated ERβ at the mRNA level. Hypermethylation in the estrogen receptor beta (ERβ) promoter was observed after treatment with 1nM DEHP for 24 h, suggesting that DEHP alter epigenetic programming through changes in the DNA methylation to modify the chromatin structure and change the accessibility of DNA to transcription factors. When breast cancer cells were treated with letrozole (200nM and DEHP (1nM) together, they survived, whereas those treated with letrozole alone did not survive. Aromatase mRNA and enzyme levels were higher in the DEHP treated cells by comparison with sham control MCF7/Aro cells. Nonmalignant MCF-10A breast epithelial cells showed a proliferation advantage (MTT assay) by up regulation of ERα as well as aromatase expression when treated with 1nM DEHP. Aromatase transgenic mice treated with 10mg/Kg b.wt of DEHP over a period of 30 days resulted in the excessive ductal branching density and epithelial outgrowth in the mammary gland. The present data suggest that dietary accumulation of DEHP through plastic food containers, water bottles, etc. may contribute to risk of hormone sensitive breast cancer in women and chemoinsensitivity and or drug resistance in breast cancer patients.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-02-01.
P4-02-07: Influence of the Progesterone Receptor on the Prognosis of Breast Cancer in Interaction with Other Prognostic Factors.
Authors: Salmen JC , Fasching PA , Hepp P , Jueckstock J , Haeberle L , Mohrmann S , Beckmann MW , Hartmann A , Wachter DL , Friese K , Janni W , Rack B 
Published: June 2012

Abstract
Introduction: The expression of the estrogen receptor (ER) and/or the progesterone receptor (PR) is a predictive factor for the response to endocrine treatment and to chemotherapy in primary breast cancer. Knowledge about the prognostic relevance of the PR is rare and partly controversial. Aim of this retrospective study was to analyze the prognostic relevance of PR.
Methods: Between 1995 and 2008, data from 5,144 patients with heterogeneously treated primary breast cancers have been collected in 3 German university hospitals.
The laboratories used immunhistochemical assays for the investigation of the ER and PR.
The PR-expression was correlated with patient and tumor characteristics.
For each outcome parameter overall survival (OS), distant disease free survival (DDFS) and local recurrence free survival (LRFS) cox proportional hazad models were built. Furthermore the effect of the PR status was analyzed according to tumor subgroups.
Results: PR status was associated with a more favourable OS, DDFS and LRFS in the univariate analysis. PR remained an independent prognostic factor for OS and DDFS but not for LRFS in the cox proportional hazard model.
For OS and DDFS the prognostic effect of PR seemed to be consistent among the subgroups and was significant for most of them. Comparing subgroups there was a difference between the HR for ER negatives and ER positives. In ER negative tumors the prognostic effect of the PR seemed to be larger (HR=0.40; 95%CI: 0.25−0.63) than in ER positives (HR=0.68; 95%CI: 0.53−0.87). For all other subgroups there seemed to be no interaction between PR status and the other prognostic factors.
Conclusion: PR positivity results into a similarly favourable prognosis in ER negative and ER positive patients. ER positivity alone seems not to be sufficient to define a group of patients with the most favourable prognosis. On the contrary, patients with ER positive, PR negative tumors have a signicantly deteriorated prognosis and seem to be a patient group, which should be investigated concerning drug resistance mechanisms.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-02-07.
P4-07-08: Subsets and Molecular Signatures of Circulating Tumor Cells in Breast Cancer Brain Metastasis.
Authors: Marchetti D , Zhang L , Wetzel M , Zaidi T , Ridgway L , Schoeber W , He W , Groves MD , Katz RL 
Published: June 2012

Abstract
Background: Circulating tumor cells (CTCs) represent the “seeds” of intractable brain metastatic breast cancer (BMBC); however, properties of CTCs targeting the brain remain elusive. For example, the FDA-approved CTC platform (CellSearch™, Veridex, LLC) detects only CTCs positive for epithelial cell adhesion molecule (EpCAM) and cytokeratins (CKs), but is unable to capture any other CTC subtypes or analyze biomarkers of brain-homing CTCs. We hypothesized that profiling CTCs from BMBC patients might result in the identification of brain-colonizing CTC signatures. Materials and Methods: We employed CellSearch™ and a novel technology that uses analysis of specific antigenic markers by immunofluorescence, coupled with detecting gene amplification by fluorescence in situ hybridization on the same cells; and quantification of the signal via automated scanning (FICTION; BioView Duet-3™ system).
Results: We established that our approach was feasible by performing CTC analyses on peripheral blood mononuclear cells isolated from BMBC patients or patients not possessing overt metastatic disease. We detected a differential gene amplification for human epidermal growth factor receptor1 and 2 (EGFR and HER2, respectively). Second, the number of EpCAM-positive CTCs visualized by the BioView™ platform was at least three orders of magnitude higher than one obtained from CellSearch™ CTC analyses using the same specimen. Third, we identified the presence of CTCs positive for CKs but negative for EpCAM. Conversely, high levels of prometastatic heparanase, in conjunction with the expression of aldehyde dehydrogenase-1 (ALDH1), a known cancer stem-cell marker, were detected in CTCs from BMBC patients; with a correlation between heparanase, ALDH1, and high EGFR amplification. Finally, extensive flow cytometric/FACS analyses validated the presence of CTC subsets negative for EpCAM and CD45, a hematolymphoid marker, however enriched for heparanase/ALDH1 expression.
Discussion: These findings indicate that the BioView™ platform not only captures more EpCAM-positive CTCs than CellSearch™ but also allows the detection of novel CTC subtypes possessing varying EpCAM levels. Importantly, they suggest that profiling CTC subtypes in patients with BMBC can be relevant towards the discovery of BMBC founder CTCs. Work is ongoing to further characterize these CTC subtypes, and to assess their abilities to metastasize to brain in xenotransplantation studies using immunodeficient mice.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-08.
P4-07-10: Circulating Tumor Cells in Newly Diagnosed Inflammatory Breast Cancer.
Authors: Mego M , Giordano A , De Giorgi U , Hsu L , Lucci A , Dawood S , Woodward WA , Ueno NT , Valero V , Andreopoulou E , Hortobagyi GN , Reuben JM , Cristofanilli M 
Published: June 2012

Abstract
Background: Inflammatory breast cancer (IBC) is one of the most aggressive forms of breast cancer and is associated with special clinical and biological features. Circulating tumor cells (CTC) are an independent prognostic factor in metastatic breast cancer for progression-free and overall survival. Previously we showed that metastatic IBC patients treated with first and subsequent lines of chemotherapy had a lower number of CTC when compared with CTC levels of non-IBC patients; hence the prognostic value of CTC in mIBC patients is limited. In the present study, we investigated the prognostic value of baseline CTC in newly diagnosed IBC patients. Patients and methods: This retrospective study included 84 newly diagnosed IBC (37 stage III B or C and 47 stage IV) patients treated with neoadjuvant therapy or first line chemotherapy between January 2004 and July 2009 at the MD Anderson Cancer Center. The median age was 55 years (range, 23–78). Twenty-four (28.8%) patients were HER2 positive, 36 (42.9%) hormone receptor positive and 33 (39.3%) were triple receptor negative. CTC were detected and enumerated using the CellSearch® system before patients started chemotherapy. Progression free survival (PFS) and overall survival (OS) were calculated from the date of CTC measurement and estimated by the Kaplan-Meier product limit method.
Results: At baseline, 64 (76.2%) patients had at least ≥1 CTC and 29 (34.5%) ≥5 CTC. Proportions of patients with stage III IBC with ≥1 CTC and ≥5 CTC were lower than those of newly diagnosed stage IV IBC patients (67.6% vs. 86%; p = 0.12 and 24.3% vs. 42.6%; p = 0.11, respectively). At a median follow up of 22.4 months (range: 4.8 - 58.3 months), 48 (57.1%) patients experienced disease progression and 26 (31.0%) had died. Patients with &lt; 5 CTC had similar PFS (p = 0.36) and OS (p = 0.80) to those of patients with ≥5 CTC, respectively. We investigated the prognostic value of CTC ≥ 1 in stage III IBC patients, as well. There was no difference in PFS (p = 0.71) and OS (p = 0.15) in patients with CTC = 0 vs. those of patients with CTC ≥ 1, respectively. Moreover, we correlated CTC levels with prognosis, using different CTC threshold, but we observed no correlation between baseline CTC and patients’ outcome (Table 1). Conclusions: CTC can be detected in a large proportion of patients with newly diagnosed IBC; however, baseline CTC was not prognostic for PFS and OS. Collective dissemination of cancer cells via lymphovascular tumor emboli and/or epithelial-mesenchymal transition accompanied by inadequate detection of CTC due to lack of sensitivity of current assays may account for limited prognostic value of CTC in newly diagnosed IBC. Nevertheless, sample size and study power could influence study results as well.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-10.
P4-07-11: Circulating Tumor Cells after Neoadjuvant Therapy Predict Outcome in Stage I to III Breast Cancer.
Authors: Gainer S , Krishnamurthy S , Bhattacharyya A , Lodhi A , Hall C , Kuerer H , Bedrosian I , Anderson A , Singh B , Lucci A 
Published: June 2012

Abstract
Introduction: Circulating tumor cells (CTCs) predict outcome in metastatic breast cancer, but their significance is unclear in non-metastatic patients. Furthermore, it is unclear if the presence of CTCs after completion of neoadjuvant chemotherapy (NACT) predicts worse outcome. The purpose of this study was to determine if CTCs after NACT predicts worse outcome.
Methods: Clinical stage I-III breast cancer patients seen at a single tertiary cancer center provided informed consent to participate in an IRB-approved study involving collection of blood (7.5 ml x 2 tubes) at the time of surgery for their primary breast cancer. CTCs were detected using the Cell SearchTM system. A positive result was defined as the presence of one or more cells per 7.5 ml blood since the threshold for positivity has not been established in non-metastatic breast cancer. Statistical analyses used chi-square and Fischer's exact test.
Results: One hundred and twenty patients were prospectively enrolled. Median age was 50 years and median follow-up was 33 months. Eight percent of patients had T1 disease, 35% T2, 18% T3, and 39% T4. Fifty-three percent of patients (63/120) had hormone receptor positive disease. Thirty-two percent of patients (38/120) were HER-2 positive. Thirty percent (36/120) were triple negative. Seventy-eight percent (91/120) had lymph node positive disease. Two or more CTCs were present in 9% of patients (11/120). Of the 11 patients who died, 3 had 2 or more CTCs (P=0.08). Of the 20 who relapsed, 6 had 2 or more CTCs (P=0.0019).
Conclusions: Presence of two or more CTCs after NACT predicted worse relapse free survival in patients with stage I-III breast cancer.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-11.
P4-07-15: Insulin-Like Growth Factor Receptor I (IGFIR) Expression in Circulating Tumor Cells (CTCs) of Patients with Early and Metastatic Breast Cancer (BC).
Authors: Spiliotaki M , Markomanolaki H , Kokotsaki M , Kallergi G , Mavroudis D , Georgoulias V , Agelaki S 
Published: June 2012

Abstract
Background: Components of the insulin-like growth factor system are deregulated and IGFIR overexpression is commonly observed in BC, however the expression of the receptor in CTCs of patients with BC has not been studied.
Methods: IGFIR expression was assessed in CTCs from 65 patients with early and 101 with metastatic breast cancer before the start of adjuvant and first-line chemotherapy, respectively. Peripheral blood mononuclear cells’ (PBMCs) cytospins were stained with a monoclonal A45-B/B3 anti-cytokeratin (CK) antibody and IGFIR β-subunit anti-rabbit antibody. IGFIR(+)CK(+) CTCs were detected using immunofluorescent microscopy (Ariol system). Phosphorylated IGFIR was also evaluated after staining with phospho-IGFIR-β (Tyr1131)/Insulin Receptor-β (Tyr1146) antibody.
Results: CK(+) CTCs were detected in 23 (35.3%) patients with early and 48.5% with metastatic BC. IGFIR(+) CTCs were identified in all (100%) patients with early and in 38 (78%) out of 49 patients with metastatic BC (p=0.014). Eighteen (78%) out of 23 patients with early disease had exclusively IGFIR(+) CTCs and 5(22%) had both IGFIR(+) and IGFIR(−) CTCs. There were no patients in whom exclusively IGFIR(−) CTCs were identified. The respective values in patients with metastatic disease were 19 (39%), 19 (39%) and 11 (22%) (p=0.004, compared to early disease). The median percentage of the expression of IGFIR(+) and IGFIR(−) CTCs per patient was 100% (range 25–100) and 0% (range 0–75), in early and 68% (range, 0–100) and 32% (range 0–100), in metastatic disease, respectively (p=0.003). A total of 222 and 386 CTCs were detected in patients with early and metastatic disease, respectively. IGFIR expression was observed in 84% and 64% of all detected CTCs in adjuvant and metastatic patients, respectively (p&lt;0.001). Phosphorylated IGFIR has been evaluated in PBMCs’ cytospins from 6 patients with adjuvant and 6 with metastatic disease. Interestingly, among 18 CTCs detected in early BC, all expressed phosphorylated IGFIR, whereas, among 34 CTCs identified in metastatic patients, none expressed the phosphorylated form of the receptor. The evaluation of phosphorylated IGFIR is ongoing and updated results will be presented.
Conclusions: IGFIR expression is commonly observed in CTCs of patients with BC. IGFIR expression is detected in a higher proportion of patients and in a higher proportion of the total number of CTCs identified in early compared to metastatic disease. The above observations suggest that metastatic progression is associated with loss or downregulation of IGFIR expression in breast cancer.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-15.