bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3365: Identification of target antigens on breast cancer stem cells using phage-developed scFv antibodies: A Proteomic Approach
Authors: Anurag Shukla , Krag (Mentor) David N. 
Published: February 2011

Abstract
The term ‘cancer stem cell’ has only recently emerged, and is defined as a cancer cell that has the ability to self-renew and give rise to another malignant stem cell, as well as differentiate to give rise to the phenotypically diverse non-tumorigenic cancer cells. The ‘cancer stem cell’ hypothesis emerged from the fact that tumors contain a heterogeneous mixture of cells and that not all the cells within a tumor contribute to tumor growth. Using phage display technology, our previous studies have identified two single chain variable fragment (scFv) antibodies (clones 207, 208) that were found to specifically bind human SUM159 breast cancer stem cells (BCSC). We have also shown in a murine xenograft tumor model prepared from the implanted SUM159 cells that these scFv antibodies predominantly bind to the cells located at the periphery of the tumors. Taking in light of these discoveries, the next logical question to be investigated was, “What cellular-antigens are these scFvs binding to?” In order to answer this in the present investigation, we used proteomic approaches based on a small scale immunoprecipitation, followed by purification and mass-spectrometry-based identification of the binding target antigens. A pure population of BCSC was acquired by flow cytometry, using ALDEFLUOR®-based sorting of the SUM159 cell line. Cell lysates of the sorted BCSC were prepared and the target antigens were immunoprecipitated with scFv-207 and scFv-208 antibodies using a solid-state immunoprecipitation assay. The immunoprecipitated targets were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The target antigens were purified and mass-spectrometric techniques (LQT-MS/ESI mass-fingerprinting) were employed to compare the proteomic data to protein databases. The details of the recovery of peptide-based target antigens and their identification using the proteomic approach as outlined above, will be presented and discussed. The identification of BCSC-specific targets will be a crucial step in designing and developing better and more specific antibody-based therapies against breast cancer.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3365.
Abstract 3369: Discordant immunohistochemical expression patterns of four different CD133 antibody clones in glioblastoma
Authors: Hermansen Simon K. , Christensen Karina G. , Jensen Stine S. , Schrøder Henrik D. , Kristensen Bjarne W. 
Published: February 2011

Abstract
The putative tumor stem cell marker CD133 is the marker of choice for identifying brain tumor stem cells in gliomas, but the use of different antibody clones recognizing different epitopes with different glycosylation status, confuses the field. In this study, we sat out to highlight if current discordant CD133 observations could be a result of using different CD133 antibodies for immunohistochemical identification of CD133. Paraffin embedded sections of glioblastoma, kidney, pancreas and placenta tissue as well as glioblastoma and retinoblastoma cell lines were stained with four different CD133 antibody clones and analyzed using light microscopy. Ten consecutive sections of glioblastomas were analyzed with each of the four CD133 clones using quantitative stereology. Results revealed presence of CD133+ niches in glioblastomas, often in close relation to blood vessels, using all four antibody clones. The distribution of identified niches did, however, rarely correspond among each antibody clone. Staining of glioblastoma single and niche cells was predominantly cytoplasmatic, which is opposed to the membranous staining observed in epithelial cells in kidney, pancreas and placenta tissues. Quantitative stereology revealed vast dissimilarities regarding fractions of CD133+ niches and single cells among the CD133 antibody clones. Generally, the fraction of CD133 positivity identified by clone W6B3C1 was significantly higher than CD133 fractions identified by clones AC133, ab19898 and C24B9. Furthermore, clone W6B3C1 was the only clone to stain tumor blood vessels. In conclusion, we report that using different CD133 antibodies for immunohistochemical identification of CD133+ cells on paraffin sections will most likely cause dissimilar results. Thus, direct comparison of CD133 studies using different primary CD133 antibodies should be performed with caution.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3369.
Abstract 3372: Analysis of putative tumor stem cell markers in the NCI-60 tumor cell line panel
Authors: Stuelten Christina H. , Mertins Susan D. , Busch Johanna I. , Gowens Meghan , Scudiero Dominic A. , Burkett Mark W. , Hite Karen , Alley Michael , Hollingshead Melinda , Shoemaker Robert H. , Niederhuber John E. 
Published: February 2011

Abstract
Tumor stem cells or cancer initiating cells are tumor cells that can regenerate a recurring tumor or a metastasis. A variety of cell surface and other markers have been associated with identification and characterization of tumor stem cells. We investigated the expression of a number of these putative stem cell markers (CD15, CD24, CD44, CD133, CD166, CD326, PgP, and aldehyde dehydrogenase) in the NCI60 tumor panel. A spectrally compatible set of labeled antibodies was designed to enable simultaneous evaluation of six markers (CD44, CD24, CD133, CD166, CD326 (EpCAM), and PgP, and forward (FSC) and side scatter (SSC). Marker expression patterns were analyzed by multiple component analysis and correlated with clonogeneic potential of cell lines (2D colony formation assay, anchorage independent colony formation in soft agar assay). Additionally sphere formation in suspension culture and the capacity of cell lines to form tumors in vivo upon injection with matrigel was assessed for colon cancer cell lines. Analysis of expression of single markers and co-expression of up to 6 markers demonstrated that all stem cell markers investigated are expressed in cell lines of the NCI-60 panel. Patterns of co-expression of these markers as defined by multiple component analysis tracked primarily with tumor type, but individual patterns were also observed to occur in multiple tumor types. In the breast cancer panel the patterns of co-expression segregated with the known molecular sub-types (basal, luminal, normal-like) of the tumor cell lines. Cells from colonosphere cultures generated from the colon tumor panel using serum-free, growth factor supplemented medium showed subtly different co-expression patterns. Both sphere-derived and bulk cultured colon tumor cells were highly tumorigenic in NOD/SCID mice and tumor formation was observed following inoculation of 10-100 cells. Only two out of seven of the colonosphere derived cell populations had enhanced tumor initiating ability, but did not share differences in stem cell marker display with respect to the unselected bulk cultures. Furthermore, marker expression patterns did not significantly correlate with in vitro colony formation (2D culture, soft agar). Our results demonstrate a high degree of complexity and heterogeneity in tumor stem cell marker display that can be influenced by culture conditions and relates to the histological classification of tumors rather than to the clonogenic potential of cells in cell lines of the NCI60 panel.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3372.
Abstract 3379: Role of E-cadherin in radiation resistance of human breast cancer cells
Authors: Yuan Yuhui , Liu Jenny , Meyn Raymond E. , Munshi Anupama 
Published: February 2011

Abstract
E-cadherin is the major adhesion protein associated with epithelial cells loss of its expression is diagnostic of the epithelial to mesenchymal transition (EMT). Our preliminary data suggest that EMT, detected as the loss of E-cadherin expression, may regulate tumor cell radiosensitivity, i.e. cells that have undergone EMT are relatively radioresistant compared to the lines that have retained the epithelial phenotype, which typically are relatively radiosensitive. To definitively test this hypothesis we compared expression levels of E-cadherin and other EMT related markers in ER-a negative (MDA-MB-231 and Hs578t) and ER-a positive (MCF-7) human breast cancer cells. Clonogenic cell survival assays showed that the cell lines expressing estrogen receptor (MCF-7) were more sensitive to increasing doses of radiation and had high expression of E-cadherin. Treatment of MCF-7 cells with 100nM siRNA to E-cadherin for 72 hrs made the cells more resistant to radiation with the surviving fraction changing from 42.3% in control cells to 56.4% in siRNA treated cells. In contrast, ER negative cells (MDA-MB-231 and Hs578t) had no detectable expression of E-cadherin and were more radioresistant. We transfected MDA-MB-231 cells with a CDH1-expression vector and isolated stable clones. These clones were selected and tested for radiosensitivity. MDA-MB-231 cells transfected with a control vector (pCMV) served as controls. Restoring E-cadherin expression radiosensitized the cells compared to the control vector cell line, suggesting that restoration of E-cadherin expression in mesenchymal-like cells produces a radiosensitizing effect. Thus, there was a general correlation between EMT, based on loss of E-cadherin expression, and radioresistance. Overall, our results suggest that E-cadherin interacts with radiation and enhances the radioresponse of human breast cancer cells. A detailed investigation of the mechanism is ongoing.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3379.
Abstract 3388: Selective GFP labeling of disseminated cancer with a telomerase-specific adenovirus (OBP-401) to report recurrence after resection
Authors: Kishimoto Hiroyuki , Urata Yasuo , Fujiwara Toshiyoshi , Bouvet Michael , Hoffman Robert M. 
Published: February 2011

Abstract
In order to achieve improved resection of disseminated cancer we used a telomerase-specific replicating adenovirus expressing GFP (OBP-401, Telomelysin®-GFP) to label tumors in vivo. Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of telomerase which is highly active in cancer cells but quiescent in most normal cells. OBP-401 contains the replication cassette, in which the hTERT promoter element drives expression of E1 genes and the GFP gene. Therefore, OBP-401 can selectively replicate in and label tumor cells with GFP. We previously demonstrated that in a peritoneal carcinomatosis mouse model of colon cancer, OBP-401 administration specifically labeled tumor cells in vivo with GFP fluorescence and enabled fluorescence-guided surgical navigation (Proc. Natl. Acad. Sci. USA, 1-6, 14514-14517, 2009; Molecular Cancer Therapeutics 8, 3001-3008, 2009). However, technical difficulties in removing microscopic tumors still remained to be solved since tumor could recur after fluorescence-guided resection. In the present study, we report an additional use of OBP-401 for surgical cure of cancer. Several weeks after cytoreduction surgery with OBP-401 GFP labeling, recurrent tumor tissues were also observed by GFP expression which could be resected under fluorescence guidance. These results indicate that OBP-401 treatment enabled fluorescent detection of subsequent recurrence after cancer surgery for the potential cure of early recurrence. The results suggest future human use of OBP-401 in cancer surgery.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3388.
Abstract 3391: Tie2 signaling regulates osteoclastogenesis and osteolytic bone invasion of breast cancer
Authors: Min Yongfen , Ren Xiubao , Lin Charles 
Published: February 2011

Abstract
Breast to bone metastasis is a common occurrence in the majority of patients with advanced breast cancer. The resultant metastases are incurable, are associated with bone destruction and high rates of morbidity. Understanding the underlying mechanisms of how metastatic tumor cells induce bone destruction is critically important. We previously reported that Tie2, a receptor tyrosine kinase, is significantly increased in human breast cancer tissues compared to normal and benign breast tumors, and regulates tumor angiogenesis. In this study, we identify a new function of Tie2 in osteoclastogenesis and osteolytic bone invasion of breast cancer. Tie2 is present in hematopoietic stem/precursor cells. Genetic deletion of Tie2 or neutralization of Tie2 function using soluble Tie2 receptor impaired osteoclastogenesis in an embryonic stem (ES) cells differentiation assay. In contrast, deletion of Tie2 has no effect on osteoblastogenesis. As monocyte has the potential to become osteoclast and Tie2 is present in certain population of monocyte, we isolated Tie2+ and Tie2- monocyte. We observed a dramatic reduction of osteoclastogenesis in Tie2- monocyte compared to Tie2+ and total monocyte. These data together reveal a direct role of Tie2 signaling in osteoclast differentiation. Consistently, neutralization of Tie2 activity in vivo significantly inhibited osteolytic bone invasion and tumor growth in a mammary tumor model, which correlated with a significant reduction of osteoclast and tumor angiogenesis. Collectively, these findings identify Tie2 a therapeutic target for controlling not only tumor angiogenesis, but also osteolytic bone metastasis.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3391.
Abstract 3393: Identification of genes mediating early dissemination of tumor cells in breast cancer
Authors: Wikman Harriet , Müller Volkmar , Kemming Dirk , Riethdorf Sabine , Eylmann Kathrin , Kropidlowski Jolanthe , Eils Roland , Jänicke Fritz , Streichert Thomas , Brors Benedikt , Pantel Klaus 
Published: February 2011

Abstract
The presence of disseminated tumor cells in bone marrow (BM) at primary breast cancer diagnosis is an independent prognostic factor. We have recently shown that there is a specific gene expression signature associated with BM micrometastasis in lung cancer patients (Wrage et al., CCR 2009). Our aim was therefore, to assess whether early metastatic spread of breast tumor cells into BM is also associated with a specific genetic signature. The gene expression profiles of primary early stage breast cancer patients (T1-2, N0, M0) with (n=15) and without (n=15) early tumor cell dissemination into BM were analyzed using the Affymetrix GeneChip platform. The BM status was assessed by immunostaining the BM samples with anti-cytokeratin antibody A45-B/B3. Gene expression data were normalized using gcrma and customized chip description files were used to re-map all probes to ENSEMBL transcripts. Rank sum test analysis was used to obtain transcripts that were significantly differentially expressed between BM positive and BM negative patients. Five publicly available breast cancer and three lung cancer expression data sets were used to correlate the findings with survival information.
When using false discovery rate of 0.2 and a p-value&lt;0.001, 28 genes were found significantly down regulated and only 4 genes significantly up regulated in the BM positive breast cancer group. The median fold-change between the BM positive and negative groups was 3.56. Quantitative RT-PCR verifications in primary tumors and metastases validated our findings.
The five large breast cancer data sets consisting of 1621 patients in total were used for in silico validations. Among the down-regulated genes 17 showed a significant association with survival in at least one data set, whereas 6 genes showed an association in at least two data sets. Among the four up-regulated genes a high expression of one gene was associated with shorter survival in two data sets whereas another gene was associated with shorter survival in one data set.
In summary, we could identify a set of potential key regulators of early hematogeneous spread of tumor cells. These potential new targets might be used to prevent metastatic relapse by eliminating DTC before the occurrence of overt metastases. Some of the identified genes are supposed to play a role only for the early steps of the metastatic cascade, i.e. dissemination, whereas others were shown also to be important for metastatic out-growth in distant organs and thus having a high impact on the survival of a patient.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3393.
Abstract 340: Kaempferol inhibits angiogenesis and tumorigenesis by regulating Akt-HIF, cMyc-p21, and ERRα genes
Authors: Luo Haitao , Rankin Gary , Federoff Ann , Juliano Noelle , Jiang Bing-Hua , Chen Yi C. 
Published: February 2011

Abstract
This study was designed to investigate kaempferol's effects on VEGF expression and angiogenesis in ovarian cancer cells and the underlying mechanisms/pathways responsible for these effects.
Kaempferol's effects on VEGF expression in ovarian cancer cells, OVCAR-3 and A2780/CP70, were studied with ELISA and a VEGF promoter reporter assay. In-vitro and in-vivo angiogenesis were studied with human umbilical vein endothelial cells and chicken embryo chorioallantoic membranes, respectively. Expression or phosphorylation of pertinent genes in ovarian cancer cells treated with kaempferol (0-160 µM) was examined with RT-qPCR, western blot, or ELISA as appropriate. To investigate kaempferol's effects on VEGF expression, the expression of certain genes was either enhanced by transfection of plasmid DNA or knocked down by transfection of siRNA, and the resultant effects evaluated by using a VEGF promoter reporter assay or RT-qPCR.
Our study found that kaempferol is effective in inhibiting VEGF expression, in-vitro and in-vivo angiogenesis, and in-vivo tumorigenesis at physiologically relevant concentrations (e.g. 40 µM). We further looked into mechanisms/pathways for these effects, and confirmed a role for Akt and HIF-1α in kaempferol's inhibition on VEGF expression. We discovered that a new HIF-1α-independent pathway is also involved in VEGF regulation. Our results showed that kaempferol executes its effects on VEGF expression through regulating ERRα but not PPARGC1A in OVCAR-3 and A2780/CP70 cells. We also identified cMyc/p21 as a novel pathway for kaempferol's inhibitory effects on VEGF expression in ovarian cancer cells.
Our study found that kaempferol is effective for angio-prevention in ovarian cancer cells, and new information was obtained on the mechanisms/pathways for kaempferol's effects. As a dietary flavonoid, kaempferol is a good candidate for angio-prevention and primary prevention of ovarian cancers, and it deserves further investigation in animal studies and human trials.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 340.
Abstract 3402: Knockdown of TWIST1 increases chemosensitivity of osteosarcoma cells
Authors: Xu Gufeng , Shen Jianhe , Yu Alex , Wang Hongmei , Man Tsz Kwong , Lau Ching C. 
Published: February 2011

Abstract
Knock-down of TWIST1 increases chemosensitivity of osteosarcoma cells
Texas Children's Cancer Center; Department of Pediatrics,
Baylor College of Medicine, Houston, TX 77030
TWIST1, a basic helix-loop-helix (bHLH) transcription factor, has previously been reported to be involved in cancer metastasis, invasion, drug response, and osteoblast differentiation induced by bone morphogenic protein. Based on expression profiling, we have previously identified a chemoresistance signature in osteosarcoma that could predict at the time of diagnosis the response to neoadjuvant chemotherapy. One of the 45 genes in the chemoresistance signature is TWIST1 whose expression level was significantly higher in osteosarcomas that were subsequently found to be more chemoresistant. To investigate the involvement of TWIST1 in chemoresistance of osteosarcoma at the cellular level, we first demonstrated that the IC50 of doxorubicin but not cisplatin treatment in eight osteosarcoma cell lines correlated with the endogenous TWIST1 expression level. We then tested the hypothesis that down-regulation of TWIST1 expression through RNAi in osteosarcoma cell lines with high TWIST1 expression could restore the chemosensitivity in these cells. Using two independent shRNAs to knock-down TWIST1 in HOS, SJSA-1 or 143B cells, we were able to show that the transduced cells became more sensitive to doxorubicin treatment as compared with the parental cells or control cells that were transduced with shRNAs with scrambled sequences. The results of the cytotoxicity assay were confirmed by the clonogenic assay using single colonies of stable transfectants with HOS cells. Based on these results, we concluded that TWIST1 is involved in chemoresistance of osteosarcoma cell lines and that down-regulation of its expression through RNAi would sensitize osteosarcoma cells to doxorubicin. However, we did not observe increased chemoresistance with overexpression of TWIST1 in osteosarcoma cell lines that have low levels of TWIST1 expression, suggesting that TWIST1 alone is not sufficient to cause chemoresistance in osteosarcoma cells. Identification of downstream targets of TWIST1 that could mediate chemoresistance by comparing expression profiles of TWIST1-knockdown clones with parental and scrambled controls is ongoing. In summary, these results validate our previous finding that TWIST1 can be used as a potential marker for predicting chemoresistance in osteosarcoma and suggest that modulating TWIST1 or its downstream targets could be considered as a novel strategy to overcome chemoresistance in osteosarcoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3402.