bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of tumor stem cells among circulating epithelial tumor cells (CETC) and relationship to therapy response.
Authors: Hekimian K , Stein EL , Pachmann U , Pachmann K 
Published: December 2010

Abstract
Abstract #5053
Background: It has been shown that the metastatic process is highly inefficient. Thus in the experimental setting, using breast cancer cell lines, only 0,1 to 0.01% of the injected cells are capable of forming metastases. With respect to cells released form primary tumors it is neither known, how many cells survive in the circulation nor what proportion is capable of forming metastases. Therefore we have attempted to determine the fraction of stem cells among the CETC and to correlate their frequency to relapse.&#x2028; Material and Methods: Tumor cells were quantified with an automated microscope (Laser Scanning Cytometer®, Icis or ScanR) from anticoagulated blood drawn before each new therapy cycle from patients treated with systemic chemotherapy after surgery and subsequent maintenance therapy. After red blood cell lysis leucocytes were stained with PE-anti-CD45 and tumor cells with FITC-anti-EpCAM. Tumor stem cells were tried to define in 2 ways: 1. Using PE-conjugated anti-CD24 Epithelial antigen positive cells were counterstained and the CD24 negative cells determined. 2. Using the Aldefluor method epithelial cells staining intracellularly positive were determined and changes registered as % increase or decrease. The response to therapy was correlated to outcome.&#x2028; Results: Both methods were well applicable. With the anti-CD24 counter stain, most CETC stained positively. A minor fraction of less than 1% of CETC was lacking CD24 staining and was regarded as the CD24 negative stem cell population. With regard to the Aldefluor method, both green fluorescing FITC anti-CD326 and red fluorescing Dye-anti-CD326 were used for screening of CETC and subsequently green intracellular fluorescence was determined inside the CETC. Aldefluor positive CETC also were in the range of 1%. Patients with CETC increasing during systemic chemotherapy which are defined as poor prognosis patients are now investigated for their proportion of stem cells during CETC increase.&#x2028; Discussion: These analyses will help to clarify whether an increase in CETC during systemic chemotherapy is due to tumor stem cells, surviving conventional chemotherapeutic agents and whether they might be susceptible to new agents.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5053.
Low proteasome activity as a means to track and target breast cancer stem cells in-vivo.
Authors: Lagadec CH , Vlashi E , Dolla Donna L , McBride W , Pajonk F 
Published: December 2010

Abstract
Abstract #5055
Based on clinical observations, the existence of cancer stem cells (CSCs)/cancer initiating cells (CICs) in solid cancers has been postulated by radiation biologists and oncologists for decades. According to the stem cell hypothesis, only a small number of CSCs/CISs within a tumor have the ability to repopulate an entire tumor while their progeny does not. CSCs/CISs in solid tumors can now be identified prospectively in gliomas, head & neck cancers, pancreatic cancers, colon cancers, prostate cancers, melanomas, and in breast cancers. CSCs/CISs are thought to be mostly quiescent and relatively resistant to conventional anti-cancer therapy.&#x2028; Breast CSCs/CICs are enriched in cell populations with high CD44 and low or absent CD24 expression. Unfortunately, detection of breast CSCs/CISs, using CD44 and CD24 expression analysis, requires dissociation of the tumors and antibody staining for surface markers. We recently discovered that cancer stem cells, and specially breast CSCs/CICs, have low proteasome activity. In order to utilize this novel marker for the identification of breast CSCs/CICs, we developed retroviral vectors coding for fusion proteins between thymidine kinase (TK), the fluorescent protein ZsGreen and the c-terminal degron of murine ornithine decarboxylase (cODC). We stably transfected human breast cancer cells lines (MCF-7, MDA-MB-231, T47-D) with this reporter gene construct for 26S proteasome activity.&#x2028; Our reporter construct allowed us to track CSCs/CICs responses to radiation therapy in vivo via fluorescent imaging, but also to target them selectively using suicide gene (TK) therapy. Thus, the use of thymidine kinase in our fusion constructs allows for specific elimination of this cell population by ganciclovir preventing self-renewal in-vitro and causing T47-D and MDA-MB-231 tumor xenograft regression in vivo.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5055.
ALDH1 expression in human breast carcinoma.
Authors: Bhargava R , Beriwal S , McManus K , Dabbs DJ 
Published: December 2010

Abstract
Abstract #5057
Aldehyde dehydrogenase 1 (ALDH1) is an enzyme responsible for oxidation of intracellular aldehydes. It has recently been shown to be a marker of "stem cells". It is hypothesized that breast cancer response to chemotherapy and breast cancer specific survival (BCSS) may be related to the presence and/or amount of self-renewing "stem cells".&#x2028; Since breast cancer molecular classes have distinct prognosis and show variability in response to chemotherapy, ALDH1 immunohistochemical (IHC) expression was analyzed in 189 invasive breast carcinomas (IBCs) to study its correlation to breast cancer molecular classes. The IBCs were classified using immunohistochemical (IHC) surrogate (to molecular classes) markers-estrogen receptors (ER), progesterone receptors (PR) and HER2. ER and PR were scored using a semi-quantitative scoring method modified from previously described “H-score” method with a dynamic range of 0-300. HER2 was considered positive only if 3+ by IHC or amplified (HER2 to chromosome 17 ratio of &gt;2.2) by FISH. The tumors were divided in 6 groups as follows: luminal A (LUMA; ER score 200 or higher, HER2 negative); ERBB2 (ER and PR score 10 or less, HER2+); triple negative (TN; ER and PR score 10 or less, HER2 negative); luminal A-HER2 hybrid (LAHH; ER score 200 or higher, HER2+); luminal unclassified HER2 negative (LUHN; ER or PR score 11-199, HER2 negative); luminal unclassified HER2 positive (LUHP; ER or PR score 11-199, HER2+). THE IBCs were represented with 3-fold redundancy on tissue microarrays (TMAs). The TMAs were stained with ALDH1 antibody (clone 44, dilution 1:150; BD Biosciences). Any staining for ALDH1 was considered as positive and results were analyzed based on %age of positive cells and semiquantitative IHC score with a dynamic range from 0-300 (as described above).&#x2028; ALDH1 was differentially expressed in various molecular classes (p=0.0007).&#x2028; &#x2028; Our results suggest that strong receptor positive tumors (LUMA) have the most committed or differentiated cells, while receptor negative or low receptor positive tumors (TN, LUHN) have higher number of progenitor or "stem cells". These differences likely account for tumor chemotherapeutic response and BCSS between ER+ and ER negative tumors. HER2+ tumors have intermediate range of "stem cells" and likely have mechanisms other than presence of "stem cells" that explains aggressive tumor growth and response to chemotherapy.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5057.
Reduced self-renewal ability and drug resistance by inhibition of notch-4 and ABCG2 in anoikis-resistant MDA-MB-231 breast cancer cells.
Authors: Ko E , Han W , Noh D 
Published: December 2010

Abstract
Abstract #5059
Background In this study, we aimed to investigate the effect of anoikis resistance on drug responsiveness and tumor initiating ability in MDA-MB-231 breast cancer cell line, and to determine whether ABCG2 inhibitor and notch-4 inhibitor will modulate the drug resistance and self renewal ability of anoikis-resistant cells. Methods Anoikis-resistant MDA-MB-231 cells isolated from the MDA-MB-231 cell line using sequential passages through the floating culture system and tested the tumor initiating ability (mammosphere-forming efficacy in vitro and limiting dilution transplantation in vivo), tumor growth rate, and drug responsiveness. Results Anoikis resistant cells were shown to have a greater mammosphere forming efficacy than parent cells (19% versus 2%, P&lt;.001). Similarly, both tumor formation rate and growth rate of anoikis-resistant cells were greater than parent cells when injected into NOD/SCID mice. Anoikis resistant cells were also more resistant to doxorubicin and docetaxel than parent cells. Immunoblots shown that expression of ABCG2 and notch-4 increased in anoikis-resistant cells as compared to parent cells. ABCG2 inhibitior (fumitremorgin C) and notch-4 inhibitor (gamma secretase) were found to preferentially reduce drug resistance and mammosphere-forming efficacy of anoikis resistant cells, respectively. Conclusion Acquisition of anoikis resistance in human breast cancer cells results in increased tumor initiating ability, tumor growth rate and resistance to chemotherapeutic agents. The increased expression of notch-4 and ABCG2 may provide an explanation for the increased tumor initiating ability and drug resistance in anoikis resistant cells.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5059.
Exploratory study of clonality determined by expression of tumor markers in intrinsic subtypes of breast cancers.
Authors: Kashiwaba M , Inaba T , Takeda Y , Takiyama I , Komatsu H , Uesugi N , Wakabayashi G 
Published: December 2010

Abstract
Abstract #5060
[Background] However expression profile-based intrinsic subtypes revealed heterogeneity of breast cancer, several biological issues are not clarified yet, especially in tumor development. [Objectives] In order to clarify the relationship between intrinsic subtypes and positivity of tumor markers (TMs), CEA, CA15-3, BCA225 and NCC-ST439 were measured from sera taken from patients at the relapse retrospectively. In addition to the analysis of positivity of TMs, migration of TMs were analyzed in each intrinsic subtype, especially focused on changes of CA15-3 (equivalent to soluble MUC1) to identify the heterogeneity and development to other subtypes in the meaning of TMs expression. [Methods] Sera were collected from seventy five patients of newly diagnosed metastatic breast cancer. Intrinsic subtypes were simply determined by immunohistochemical staining as Luminal A (LA) ,B (LB), HER2 and TN. The positivity of TM was defined if it elevated 20% higher than normal upper limit. [Results] The positive rate of any TMs were higher in order of LA, LB, HER2 and TN. There was significant difference between Luminal (LA+LB) and TN in positive rate of TMs(p&lt;0.05). If focused on mammary epithelium development marker MUC1 (CA15-3 as a soluble form), it was significantly elevated in Luminal (LA+LB) than HER2 and TN(p&lt;0.05). Interestingly, 18 of 23 (72.3%) TN tumors showed all TMs negative at the relapse, although 4 of 18 (22.2%) TN tumors developed to TMs positive after palliative chemotherapies. [Conclusion] Luminal type showed higher expression of TMs at the relapse. It might be explained by the fact that common TMs were selected as responsive serum proteins to the tumor volume of dominant population of breast cancer by chance. But if we integrate the idea that CA15-3 as a development marker, luminal cancer was developed from ER+ highly developed progenitor and HER2 and TN might be developed from ER- progenitor lineage. The migration of TMs of TN after palliative chemotherapies might be illustrated with clonal selection by chemosensitivity. These phenomenon will be understood by further biological experiments and prospective clinical trials to improve the outcome of metastatic breast cancer.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5060.
Differential transcriptional response to cisplatinum in BRCA1-defective versus BRCA1-reconstituted breast cancer cells by microarrays.
Authors: Di Martino MT , Ventura M , Guzzi PH , Pietragalla A , Neri P , Bulotta A , Calimeri T , Barbieri V , Caraglia M , Veltri P , Cannataro M , Tassone P , Tagliaferri P 
Published: December 2010

Abstract
Abstract #5062
BRCA1-related breast cancer represents a distinct clinical entity characterized by basal-like molecular phenotype. HCC1937 is a BRCA1-defective breast cancer cell line which discloses higher sensitivity to cisplatinum (CDDP) as compared to the BRCA1 full-length cDNA transfected clone HCC1937/wtBRCA1. To study the molecular bases of BRCA1-related differential sensitivity to the drug, we have analyzed the whole gene expression profile of HCC1937 and HCC1937/wtBRCA1 cells following in vivo and in vitro exposure of tumour cells to CDDP.&#x2028; Differential in vivo sensitivity was evaluated in xenografted tumors in SCID mice after 4 weeks of treatment with CDDP (5 mg/kg) or vehicle. Tumors were retrieved from animals 4 hours after the last dose of drug or vehicle. In vitro data were obtained exposing HCC1937 and HCC1937/wtBRCA1 cell lines to CDDP at IC50 doses of 30 and 70µM, or at 60 or 140µM respectively, for 3, 12 and 24 hours. Gene expression profiling was performed by Affymetrix® technology using GeneArray 1.0ST. Array data were analyzed using Gene Expression Console, GeneSpring software and Ingenuity Pathway Analysis (IPA)®.&#x2028; We found up-regulation of G2/M DNA damage checkpoint pathway, in a dose- and time-dependent manner, as well as down-regulation of Notch signaling pathway in HCC1937 cells, after treatment with CDDP in vitro. Both pathways were not affected in BRCA1-reconstituted cells. Notch signaling pathway plays a key role in normal development of several tissues and its aberrant activation is linked with breast cancer tumourigenesis. Our findings suggest that sensitivity of the BRCA1-defective cells to CDDP exposure is related to the DNA-damage repair machinery due to BRCA1-deficiency but also to the modulation of survival pathways triggered by BRCA1. In vivo data analysis of HCC1937/wtBRCA1 tumours exposed to CDDP identified modulation of pathways involving AKT3 and PRKAR2B, also known as RII-BETA, a cAMP-dependent protein kinase, whereas no Notch signaling pathway modulation was detected.&#x2028; In conclusion, reconstituted expression of BRCA1 induces resistance to CDDP in vitro and in vivo but produces a different transcriptional response to drug exposure. This effect could be related to the different growth and environmental milieu as well as to the different exposure conditions. Signaling pathways involving Notch, AKT and RII-BETA are involved in these events. Our data reinforce the concept that BRCA1 offers a molecular marker for individualized therapeutical options in breast cancer patients.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5062.
Cell cycle phase progression analysis identifies unique replication phenotypes of major prognostic and predictive significance in cancer.
Authors: Loddo M , Kingsbury SR , Rashid M , Proctor I , Holt C , Young J , El Sheikh S , Falzon M , Eward KL , Prevost T , Sainsbury R , Stoeber K , Williams GH 
Published: December 2010

Abstract
Abstract #5066
BACKGROUND: The cell cycle machinery acts as an integration point for information transduced through complex and redundant upstream oncogenic signalling pathways. Multiparameter analysis of core regulatory proteins involved in G1-S and G2-M cell cycle phase transitions provides a powerful biomarker readout for assessment of the cell cycle state. We have applied this novel algorithm to breast cancer, investigating its cell cycle kinetics, and determining how this impacts on pathobiology and disease progression in-vivo.&#x2028; METHODS AND FINDINGS: Protein expression profiles of key constituents of the DNA replication licensing pathway (Mcm2, geminin) and mitotic machinery (Plk1, Aurora A, Aurora substrate Histone H3S10ph), mediators of G1-S and G2-M transition respectively, were generated for a cohort of 182 patients. Arrested differentiation and development of genomic instability was associated with increased engagement of cells into the cell division cycle (p&lt;0.0001). Three unique cell cycle phenotypes were identified; (I) well differentiated tumours composed predominantly of Mcm2 negative cells indicative of an out-of-cycle state (18% of cases), (II) high Mcm2 expressing tumours but with low geminin, Aurora A, Plk1 and H3S10ph levels (S-G2-M progression markers) indicative of a G1 delayed/arrested state (24% cases), (III) high expressing Mcm2 tumours, but also expressing high levels of the S-G2-M progression markers, indicative of accelerated cell cycle progression (58% of cases). The accelerated cell cycle phenotype had a significantly higher risk of relapse when compared with out-of-cycle and G1 delayed/arrested tumour phenotypes (HR=3.90 [1.81-8.40], p&lt;0.001). Notably high grade tumours with the G1 delayed/arrested phenotype showed an identical low risk of relapse to well differentiated out-of-cycle tumours (HR=1.00 [0.22-4.46], p=0.99), suggesting that many patients are receiving inappropriate S-G2-M phase directed adjuvant chemotherapy.&#x2028; CONCLUSIONS: This biomarker algorithm provides novel insights into the cell cycle state of dynamic tumour cell populations in-vivo, information that impacts on individualised therapeutic decisions. The cell cycle phenotype has a major influence on disease progression, identifying those patients at most risk of relapse. Importantly, it is only patients displaying an accelerated phenotype, tumours that show S-G2-M phase transit, that are likely to derive benefit from S and G2-M phase specific adjuvant chemotherapeutic agents and mechanistic drugs.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5066.
GATA3, P53, Ki67 and vascular peritumoral invasion are strongly predictive of hormonal resistance in luminal breast cancer.
Authors: Jacquemier JJ , Charafe Jauffret EE , Monville FF , Esterni BB , Extra J , Houvenaeghel GG , Xerri LL , Birnbaum DD 
Published: December 2010

Abstract
Abstract #5068
Background: Breast cancers are traditionally divided into hormone receptor positive and negative cases that guide patient management. The two luminal subtypes in gene expression profiling , A and B, are defined by high expression of ER, GATA3, and FOXA1. There is a little doubt that ER status is a strong predictor of response to endocrine therapy. Prognostic immunohistochemical biomarkers for ER-positive breast cancer include progesterone (PR) and androgen (AR) receptors, proteins related to proliferation or apoptotic resistance. The aim of this study was to identify the best predictors of success of hormonal therapy among immunohistochemical and classical factors.&#x2028; Methods: We studied 10 markers in a consecutive series of 832 cases of breast carcinoma treated at the Paoli-Calmettes Institute from 1990 to 2002 and deposited onto tissue-micro arrays (TMA): luminal-related ER, PR, AR, FOXA1, and GATA3 factors, proliferation-related KI67 and CCND1, ERBB2, anti-apoptotic BCL2, and p53. We also measured the vascular peritumoral invasion (VPI) size, Grade and lymph nodes involvement (N). On these series 145 cases had been profiled on Affymetrix microarrays. The patients had been treated with adjuvant chemotherapy and/or hormonal therapy . The 132 events observed and taken into account were metastases (MF).&#x2028; Results: Of the 67 luminal A cases of this series 63 were ER-positive, 98% were FOXA1-positive; only half of them expressed the five luminal-related markers. In 584 ER-positive patients, 200 did not receive adjuvant hormonal therapy with a highly significant difference in MF with those who received Tamoxifen (p=0.017). For the 240 cases who received hormonal therapy, the factors associated to the MF in multivariate analysis were:&#x2028; &#x2028; A prognostic score can be established summing the impact of each four parameters with a significant Logrank test : p= 0.0003.&#x2028; &#x2028; Discussion: A panel of three antibodies (Ki67, P53 and GATA3), associated with VPI can significantly improve the traditional prognosticators in predicting outcome for ER-positive breast cancer patients receiving hormonal therapy.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5068.
Sirtuin expression is decreased in malignant breast tissue and is associated with patient outcome.
Authors: Zino S , Ashraf N , Kingsmore DB , Payne AP , George W , Shiels PG 
Published: December 2010

Abstract
Abstract #5073
Background: Age is associated with increased incidence of cancer; therefore exploring factors associated with biological ageing in cancer may improve our understanding of the disease and result in new prognostic markers or therapeutic targets. Sirtuins belong to a family of genes that are involved in cell processes including DNA repair, cell-cycle regulation and ageing. SIRT6 modulates telomeric chromatin, is involved in DNA repair and the suppression of genomic instability, aberrations of which are key features of cancer cells. SIRT7 is a positive regulator of RNA polymerase I (Pol I) transcription. Recently, altered sirtuins expression has been linked with lung cancer, gliomas and thyroid cancer. This study aimed to investigate whether SIRT6 and SIRT7 expression is altered in breast tumour biopsies and to determine any association between sirtuin expression and patient outcome.&#x2028; Materials and Methods: The transcriptional expression of SIRT6 and SIRT7 was determined using real-time PCR in archival breast biopsies (73 non-malignant and 70 malignant). SIRT6 and SIRT7 expression relative to HPRT (house keeping gene) was then analysed with respect to histopathology, disease recurrence and survival.&#x2028; Results: We observed a significant decrease in the relative transcriptional expression of SIRT6 and SIRT7 in breast cancer biopsies (median for SIRT6 = 0.799 and SIRT7= 0.482) when compared with non-malignant tissue (median for SIRT6 = 1.823 and SIRT7= 0.607) (Mann-Whitney test, p &lt;0.001 and p= 0.043 respectively). There was a significant association between SIRT6 expression and tumour grade (Kruskal Wallis Test, p=0.002), whereas only a trend was observed for SIRT7 (Kruskal Wallis Test, p=0.067). Kaplan-Meier survival analysis showed that mean survival was significantly shorter in patients with lower SIRT6 expression when compared with those with higher levels of expression (9.32 years vs 13.06 years, p=0.01). A trend was observed between levels of SIRT7 expression and survival (p=0.083). Furthermore, multivariate Cox-regression analysis revealed that SIRT6 expression was independent of tumour size, grade, nodal status, and oestrogen receptor status as a survival predictor (p =0.036).&#x2028; Discussion: These results demonstrate an association between SIRT6 expression and breast cancer pathogenesis and suggest possible SIRT7 involvement. Decreased SIRT6 expression is consistent with genomic instability associated with tumourigenesis and might indicated telomeric dysfunction. Lower levels of SIRT7 are an indication of increased biological ageing in cancerous cells. Furthermore, the association between SIRT6 and both tumour grade and survival, indicates that SIRT6 might prove to be an additional prognostic marker for breast cancer patients.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5073.