bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1479: IKK-epsilon contributes to the malignant progression of ovarian cancer
Authors: Annunziata Christina M. , Hsu Sarah , Hernandez Lidia , Kohn Elise , Davidson Ben
Published: June 2012

Background and significance: The mechanism through which the NF-κB pathway affects the initiation, propagation and dissemination of ovarian cancer is unknown. I-κB kinases (IKKs) are key regulators of NF-κB signaling. Three IKK isoforms – α, β and ∈ – have been linked to oncogenesis, yet the precise components of NF-κB signaling mechanisms in ovarian cancer have not yet been dissected. IKK∈ was identified as an oncogene in breast cancer and has been associated with poor clinical outcome in ovarian cancer. This IKK isoform can regulate the innate immune response via activation of interferon-response factors, or can signal through classical NF-κB mechanisms by inactivating CYLD, a negative regulator of the pathway. Therefore, the molecular context is key to determining which oncogenic pathway is activated and how the signals will ultimately affect the cancer cel We hypothesized that IKK∈ drives ovarian cancer growth and metastasis.

Methods: The expression of IKKe was determined in primary ovarian cancer specimens and human ovarian cancer cell lines. Ovarian cancer cell lines were depleted of IKKe using RNA interference and tested in functional assays, including anchorage-independent growth, basement membrane invasion, and heterotypic cell adhesion. Orthotopic xenograft mouse models were used to determine the role of IKKe in metastasis in vivo. Gene expression microarrays established an IKKe-specific signature in ovarian cancer.

Results: We surveyed 120 ovarian cancer specimens (42 primary carcinomas, 78 solid metastases) for IKK∈ expression. Notably, cytoplasmic expression was elevated in metastatic lesions relative to primary tumor sites (p=0.03). RNA interference targeting IKK∈ in a panel of 5 metastatic ovarian cancer cell lines inhibited cell growth and prevented colony formation in soft agar. An ovarian cancer-specific IKK∈-regulated gene expression signature was identified using stably expressed shRNA targeting IKK∈. Pathway analysis of the signature indicated that IKK∈ regulates the expression of genes essential to diverse processes known to contribute to the malignancy of ovarian cancer, including TGFb and HIF1a pathways. Orthotopic xenograft experiments in mice demonstrated decreased aggressiveness of IKK∈-depleted ovarian cancer cells.

Conclusion: These data provide evidence that IKK∈ plays a key role in ovarian cancer metastasis. Understanding IKK∈-regulated signaling in ovarian cancer will identify novel pathway interactions for context-specific therapeutics in the poor prognostic group of women whose ovarian cancers over-express IKK∈.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1479. doi:10.1158/1538-7445.AM2011-1479
Abstract 149: Antisense inhibition of microRNA-21 and -221 in tumor-initiating stem-like cells modulates biological functions of pancreatic cancer including tumorigenesis, metastasis, and chemoresistance
Authors: Ischenko Ivan , Camaj Peter , Jauch Karl-Walter , Bruns Christiane J.
Published: June 2012

Introduction. Our preliminary studies identified a small population of pancreatic cancer cells with stem-like properties. These cells, called Side Population (SP) cells, were able to induce fast and aggressive tumor formation in nude mice. Cultured SP were able to differentiate into daughter SP or non-SP cells and were found to be highly chemoresistant. Furthermore, performed gene expression analysis showed a significant difference in the expression of more than 1300 genes in SP cells, among which the difference in microRNA expression between SP and non-SP cells was identified as the most interesting candidate for our further studies.

Methods. Pancreatic cancer stem-like cells from highly metastatic cell line L3.6pl were identified and characterized by flow cytometry using Hoechst 33342 dye staining. The gene expression was assessed by Affymetrix and the results were further confirmed by quantitative RT-PCR. The antagomir transfection was performed using microRNA-21 and -221 oligonucleotide antisense. Tumor cell apoptosis, cell cycle progression, chemoresistance, and invasion were quantitated by propidium iodide staining and Boyden chamber assay, respectively.

Results. In our study, some microRNAs, including miR-21, miR-221, miR-211, and miR-30c-2 were significantly upregulated in stem-like SP from L3.6pl cells. Interestingly, in these cells both miR-21 and miR-221 were involved in the modulation of expression of more than 200 genes, including RASSF6, RAB2B, TP63, TP53INP1, TP53INP2, TET1, MAPK10, MAP2K6, CDK6, TNFRSF11B, SOCS6, STK33, and SMAD7. The administration of antagomir-21 and -221 significantly reduced the SP fracture, decreased SP cell differentiation, positively affected L3.6pl cell proliferation, invasion, and chemoresistance against gemcitabine and 5-Fluorouracil.

Conclusion. Our results demonstrate the significance of both microRNA-21 and -221 in tumor-initiating capability of stem-like tumor cells in pancreatic cancer. Both microRNAs contribute to the most important biological functions of pancreatic cancer including apoptosis, metastasis, and chemoresistance, and may further serve as a potential target for pancreatic cancer therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 149. doi:10.1158/1538-7445.AM2011-149
Abstract 150: Regulation of TGFB receptor by miR21 in Sezary syndrome
Authors: Narducci Maria Grazia , Arcelli Diego , Lazzeri Cristina , Pagani Elena , Picchio Maria Cristina , Cristofoletti Cristina , Tocco Valeria , Ferracin Manuela , Sampogna Francesca , Frontani Marina , Lombardo Giuseppe Alfonso , Scala Enrico , Negrini Massimo , Caprini Elisabetta , Russo Giandomenico
Published: June 2012

Sezary syndrome (SS) represents a very aggressive form of Cutaneous T Cell Lymphomas with a median overall survival of 5.1 years (range, 0.4-18.6 years). As it appears evident there are in this disease either short survivors than long survivors. Previous studies of prognostic indicators in SS showed that circulating Sézary cell count, high CD4/CD8 ratio, advanced age, high lactate dehydrogenase serum level and a high white blood cell count were associated with an unfavorable outcome. Up to now, few data have been provided concerning possible associations between immunological and genetic markers, who might provide also clues on tumor progression in this disease. In the last 10 years we have observed more than 50 Sezary Syndromes in our Institute and phenotyped them with new immunologic markers. We have also performed genetic analysis with Single Nucleotide polymorphysms (SNPs) for evaluation of genomic imbalances, mRNA expression and lately microRNA(miRNA) expression profiling. In this study we have analyzed the expression profile of 470 miRNAs using Agilent platform array in 22 SS patients. We investigated the relationship between the expression level of miRNAs and the clinical outcome of SS patients by Kaplan-Meier method and risk assessment by multivariate analysis. We also functionally investigated the role of miR-21, mapping in one of the region more frequently amplified in SS and some of its targets. We identified 45 miRNAs differentially expressed between SS and healthy controls. Using predictive analysis, a list of 19 miRNAs, including miR-21 and miR-18a, miR-342, miR-31 and let-7 members were also found. Moreover, we defined a signature of 14 miRNAs able to discriminate patients with unfavorable and favorable outcome. We show that miR-21 knockdown increases apoptosis and modulates TGF beta receptor 2 expression in vitro. The antipoptotic effect appears to be regulated through PTEN. Conversely, we were not able to observe a direct miR-21 regulation on PDCD4 gene mapping to chromosome 10q24, a frequently imbalanced region in SS. In conclusion we have identified a new prognostic miRNAs signature in SS and characterized the role of miR-21, one of the most involved in cancer, recognized as a disease and prognostic classifier in this disease.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 150. doi:10.1158/1538-7445.AM2011-150
Abstract 1505: The role of cathepsin B in colorectal tumorigenesis
Authors: Bian Benjamin , Mongrain Sébastien , Boudreau Francois , Rivard Nathalie
Published: June 2012

Many cancers express elevated protease levels which contribute to certain aspects of tumor behavior such as growth and metastatic spread. Specifically, elevation of the cysteine protease cathepsin B has been shown to correlate with malignant progression of tumors. The majority of reports on cathepsin B expression in tumors have focused on measurements of activity or protein staining. However, multiple transcripts species have been detected resulting from alternative splicing in the 5’- or 3-untranslated regions, and possibly the use of alternative promoter regions. The specific role of these variants remains to be established. Methods: Expression of cathepsin B was analyzed in normal human intestinal epithelial cells (HIEC) and colorectal cancer cell lines (Caco-2/15, HCT116, DLD1, HT29, SW480, T84, Colo205) by qPCR and Western blot. The role of cathepsin B was examined in HT29 and DLD1 cell lines through recombinant lentiviruses encoding anti-cathepsin B short hairpin RNA (shRNA). Results: RT-PCR analyses demonstrated that the levels of the full transcript for cathepsin B containing exons 1-12 (CB) were similar between normal and cancerous cell lines. By contrast, the splice variant lacking exons 2 and 3 (CB-2,3) was expressed only in cancer cells and in biopsies from human colorectal tumors when compared to the adjacent healthy tissues. Immunofluorescence studies showed that this novel tumor form of cathepsin B (CB-2,3) was associated with nuclei and mitrochondria while the full-length cathepsin B protein (CB) was found in the lysosomes. Western blot analyses on culture media showed a strong secretion of various cathepsin B isoforms by cancer cell lines. The lentiviral infection of a shRNA which specifically knocked-down cathepsin B expression, while decreasing enzyme activity in cell lysates, did not influence colorectal cancer cell proliferation under anchorage-dependent conditions. By contrast, decrease of cathepsin B expression in HT29 and DLD1 colon cancer cell lines resulted in a marked reduction of their capacity to grow in soft agar. Levels of β-catenin protein and phosphorylated ERK1/2 were not affected following cathepsin B silencing in contrast to phosphorylated Akt which was significantly reduced. Further, migration and invasion through Matrigel was reduced by 60% in cells expressing the shRNA against cathepsin B compared to cells expressing a control shRNA. Conclusion: These results suggest that the alternative splicing of cathepsin B could contribute to the aberrant intracellular trafficking and function of cathepsin B in colorectal cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1505. doi:10.1158/1538-7445.AM2011-1505
Abstract 1507: Ectopic expresion of cathepsin G in mammary tumor cells and its role in tumor growth and osteolytic bone metastasis
Authors: Varney Michelle L. , Gregory Clint , Singh Rakesh K.
Published: June 2012

Breast cancer has a high predilection to metastasize to the bone microenvironment. The resulting lesions are predominantly osteolytic and are associated with the resulting morbidity and mortality. We have demonstrated that tumor bone interaction plays an important role in osteolytic bone metastasis mediated by dysregulation of a unique set of genes. Among these genes several proteases have been found to be up-regulated at the tumor-bone interface, one of these is Cathepsin G, a serine protease. These proteases act as modulators between the tumor and stroma. Previously, we have shown that both malignant cells and osteoclasts at the TB-interface express higher levels of Cathepsin G, which is critical for osteolytic bone metastasis. The precise role of tumor and/or host-derived Cathepsin G in osteolytic bone metastasis is not known. In this report, we examined the contribution of tumor-derived Cathepsin G by testing the hypothesis that ectopic expression of Cathepsin G modulates malignant cell phenotype, osteoclast recruitment and activation, and osteolytic metastasis. We generated stable mammary tumor cell lines constitutively expressing Cathepsin G (Cl66-CTSG). Cathepsin G-expressing tumor cells showed diminished in vitro cell proliferative potential and in vivo mammary fat pad tumor growth as compared to vector control transfected Cl66-CMV cells. We demonstrated that Cathepsin G-overexpressing tumor cells induced osteoclast activation and differentiation in vitro and tumor-induced osteolysis in vivo. Our data suggest that tumor-derived Cathepsin G might have distinct tumor modulating activities in the bone microenvironment by regulating cell proliferation and osteoclast recruitment and activation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1507. doi:10.1158/1538-7445.AM2011-1507
Abstract 1509: Analysis of interaction between tumor endothelial cells and tumor cells
Authors: Maishi Nako , Ohga Noritaka , Hida Yasuhiro , Ohba Yusuke , Kawamoto Taisuke , Akiyama Kosuke , Kitayama Kazuko , Kondoh Miyako , Osawa Takahiro , Yamamoto Kazuyuki , Inoue Nobuo , Shindoh Masanobu , Hida Kyoko
Published: June 2012

Interaction between tumor endothelial cells (TECs) and tumor cells plays a key role in the early stage of hematogenous metastasis. TECs provide the principal route by which tumor cells exit the primary tumor site and enter the circulation. We have reported TECs are different from normal endothelial cells (NECs) in various aspects, such as chromosomal abnormality and gene expression profiles. In this study, we isolated two types of TECs from different human tumor xenografts in nude mice to analyze interaction between TECs and tumor cells. One is HMTEC isolated from highly metastatic tumor and the other is LMTEC from low metastatic tumor. We also isolated NEC from dermis of normal nude mouse as normal control. HMTEC expressed higher levels of mRNA of angiogenesis-related genes than LMTEC or NEC. We hypothesized HMTECs may promote metastasis, in particular, intravasation at the primary site. We investigated the roles of TECs in tumor metastasis; 1) migration of tumor cells towards TECs, 2) adhesion to endothelial layer, 3) crossing the endothelium. Tumor cells migrated towards conditioned-media (CM) from HMTEC more than LMTEC-CM or NEC-CM in vitro. Tumor cells were more adhesive to HMTEC than to LMTEC or NEC. They migrated through the HMTEC-monolayer most among all ECs in transendothelial migration assay. These results suggested that HMTEC may help tumor cells to metastasize. Finally, we analyzed the effects of CM from highly metastatic tumor cells on NECs. Tumor CM induced mRNA expressions of several genes, such as CXCL12, VEGFA and extracellular matrix in NEC. Tumor cells more migrated towards tumor CM- treated NEC than non-treated NEC. Tumor cells adhered more to the tumor CM- treated NEC than to non-treated NEC. These results suggest that TECs “educated” in tumor microenvironment which have highly metastatic potential, may be collaborating with tumor cells for metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1509. doi:10.1158/1538-7445.AM2011-1509
Abstract 1510: Transcriptional profiling of a lethal breast cancer tumor microenvironment
Authors: Witkiewicz Agnieszka K. , Kline Jessica , Queenan Maria , Brody Jonathan , Sotgia Federica , Tsirigos Aristotelis , Lisanti Michael P.
Published: June 2012

Breast cancer growth and progression are governed by complex and reciprocal interactions between tumor cells and surrounding stromal elements. We have previously shown that a loss of stromal Cav-1 expression is associated with an increased risk of early tumor recurrence, metastasis and decreased overall survival. To identify and characterize the signaling pathways activated in Cav-1 negative tumor stroma, we performed gene expression profiling using laser micro-dissected breast cancer associated stroma.

Methods: Tumor stroma was laser capture micro-dissected using a Leica LCM system from 4 cases showing high stromal Cav-1 expression and 7 cases with loss of stromal Cav-1. Total RNA was amplified using the NuGEN™ WT-Ovation™ FFPE RNA Amplification System V2 and cDNA was hybridized to Affymetrix GeneChip® arrays. One-way ANOVA was setup to extract differentially expressed genes between Cav-1 positive and negative stromal samples.

Results: We identified 238 genes that were up-regulated and 232 genes that were down-regulated in the stroma of tumors showing a loss of Cav-1 expression (p-value < = 0.01 and fold change > = 1.5) Gene set enrichment analysis revealed “stemness”, inflammation, DNA damage, oxidative stress, hypoxia, autophagy, and mitochondrial dysfunction in the tumor stroma of patients lacking stromal Cav-1.

Conclusions: Our findings are consistent with the recently proposed “Autophagic Tumor Stroma Model of Cancer Metabolism”. In this model, cancer cells induce oxidative stress in adjacent stromal cells, which then forces these stromal cells to undergo autophagy. This, in turn, produces recycled nutrients to feed “hungry” cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1510. doi:10.1158/1538-7445.AM2011-1510
Abstract 1516: Estrogen regulated TME factors are novel modulators of neovasculogenesis and EMT in breast cancer
Authors: George Andrea L. , Rajoria Shilpi , Shanmugam Arulkumaran , Prakash Pradeep Bangalore , Suriano Robert , Tiwari Raj K.
Published: June 2012

The tumor microenvironment plays host to multiple cell types that aid in tumor metastasis and recent work has begun to focus on the impact of non-malignant cells in breast cancer progression. Tumor metastasis relies on neovasculogenesis, aided by bone marrow-derived endothelial progenitor cells (BM-EPCs), which is critical for invasive tumor growth as well as an epithelial to mesenchymal transition (EMT) by malignant cells, allowing them to break from the primary tumor site and migrate to secondary foci. The modulators of tumor induced neovasculogenesis as well as EMT need elucidation. Previously we reported that estrogen significantly enhanced BM-EPC migration to mouse mammary tumor sites in vivo, resulting in an increase in neovasculogenesis and induction of proangiogenic and prometastatic proteins including vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Using in vitro assays, we observed that estrogen leads to stabilization of the transcription factor hypoxia inducible factor 1 α (HIF-1α), a key regulator of hypoxia signaling, in the mouse mammary tumor cell line TG1-1. We observed that estrogen signaling via HIF-1α leads to an increase in VEGF, and conditioned media from TG1-1 cells treated with estrogen leads to a significant increase in human umbilical vein endothelial cell (HUVEC) migration in vitro, an effect abrogated by the anti-estrogen Fulvestrant as well as 3-(5’-hydroxymethyl-2’-furyl)-1-benzylindazole (YC1) a specific HIF-1α inhibitor. While tumor growth induces neovasculogenesis via endothelial cell recruitment, the inflammatory environment created stimulates infiltration of tumor associated macrophages, or TAMs. We further observed that conditioned media from the mouse macrophage cell line RAW264.7 induced EMT in TG1-1 cells, leading to an increase in both the EMT transcription factor TWIST and TG1-1 cell migration. Thus, an inflammatory environment leads to macrophage dependent secretion of pro-metastatic factors, resulting in breast tumor cell EMT and migratory propensity. We conclude that estrogen modulated secreted factors in different cell types influence the tumor microenvironment and have functional consequences on tumor cell growth and metastasis and may provide targets for clinical therapeutic intervention.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1516. doi:10.1158/1538-7445.AM2011-1516
Abstract 1523: α4 integrin expression is a determinant for activity of the integrin antagonist HYD1 in multiple myeloma cell lines and patient specimens
Authors: Emmons Michael F. , Gebhard Anthony , Mclaughlin Mark , Cress Anne , Hazlehurst Lori
Published: June 2012

Our laboratory previously showed that the β1 integrin inhibitory peptide HYD1 causes caspase independent cell death in myeloma cell lines. To further characterize the mechanism of HYD1 induced cell death an isogenic drug resistant variant was developed. This variant, called H929-60, was developed by chronically exposing parental H929 cells to increasing doses of HYD1 over time until a drug resistant phenotype was observed. The resistant cell lines demonstrated reduced binding of FAM-conjugated HYD1 to the cell surface compared to the parental cell line. We previously reported that HYD1 blocks α4β1 mediated adhesion to fibronectin and thus we asked whether resistance towards HYD1 induced cell death correlated with reduced α4β1 integrin expression. The resistant variant showed deceased levels of α4 integrin protein expression despite no change in RNA levels, indicating a post-transcriptional regulation of α4 expression. These changes were consistent with decreased binding to fibronectin, VCAM-1 and HS-5 stromal cells. Moreover, we demonstrated that biotin conjugated HYD1 is able to pulldown a α4 containing complex and the amount of α4 bound to biotin-HYD1 was reduced in the drug resistant variant. Reducing the expression of α4 and β1 integrins on the cell surface in H929 cells was sufficient to confer partial resistance to HYD1 induced cell death. Because the H929 resistant variant showed reduced adhesion to stroma cells, we asked whether acquisition of resistance towards HYD1 resulted in reduced levels of drug resistance in the HS-5 co-culture model of drug resistance. Using the HS-5 co-culture model, we show that the drug resistant variant H929-60 cells treated with either melphalan or velcade were drug sensitive in the HS-5 stromal co-culture model of drug resistance. Thus the drug resistant variant failed to demonstrate a cell adhesion mediate drug resistance (CAM-DR), indicating that as cells acquire resistance to HYD1 they lose resistance initiated by the tumor microenvironment. Finally, we show that HYD1 was significantly more potent in relapsed/refractory patient specimens compared to newly diagnosed patient specimens. Additionally, we show that α4 integrin expression positively correlates with HYD1 sensitivity. Together our data indicate that HYD1 is an attractive novel agent for the treatment of relapsed/refractory multiple myeloma with high levels of α4 integrin expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1523. doi:10.1158/1538-7445.AM2011-1523
Abstract 1524: Overcoming temozolomide resistance in MGMT positive glioblastoma by targeting ALDH1
Authors: Schäfer Andrea , Teufel Julian , Höpner Ingrid , Ringel Florian , Bettstetter Markus , Schlegel Jürgen
Published: June 2012

Despite aggressive therapy, including radical surgical resection, radiation, and chemotherapy, the prognosis for patients with glioblastoma (GBM) remains poor and relapse occurs regularly. Implementation of the chemotherapy drug temozolomide (TMZ), as a standard in adjuvant GBM therapy, significantly increased the overall survival of patients with an epigenetic silenced MGMT promoter (MGMT-). To date, no comparable therapeutic approach for GBM patients with MGMT expression (MGMT+) is applied.

Tumor re-growth in MGMT+ and MGMT- GBM corroborates the tumor stem cell (TSC) paradigm, postulating that a therapy-resistant subpopulation of cells harbors the ability to keep the tumor alive and growing. Recently, we presented aldehyde dehydrogenase 1 (ALDH1) as a marker for glioblastoma cells with stem cell capacity.

In this study, we demonstrate that ALDH1 overexpression in established and primary MGMT+ GBM cell lines correlates with resistance to TMZ, while concomitant inhibition of ALDH1 by 4-diethylaminobenzaldehyde (DEAB) or tetraethylthiuramdisulfide (DSF) re-sensibilized the cells significantly. Application of TMZ in combination with DEAB strikingly attenuated the stem cell capacity of both MGMT + and MGMT – cells. For further verification of the specific impact of ALDH1 on therapy resistance, shRNA constructs were applied. Moreover, immunohistochemical analysis of ALDH1 expression in specimens of glioblastoma patients revealed a significant correlation between expression of this enzyme and a poor clinical prognosis.

All these findings demonstrate that ALDH1 is a marker for brain tumor stem cells, a strong predictor of clinical outcome and a potential target for an improved therapy of MGMT positive GBM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1524. doi:10.1158/1538-7445.AM2011-1524
Abstract 1535: Increasing integrin function from within the cell sensitizes melanomas to chemotherapy
Authors: Nelson Elke S. , Folkmann Andrew , DeMali Kris
Published: June 2012

Metastatic melanoma is an aggressive skin disease for which there are no effective therapies. Emerging evidence indicates that melanomas can be sensitized to chemotherapy by increasing integrin function. Current therapies work by targeting integrins from outside the cell, resulting in complete gains or losses of integrin function that lead to mechanism-based toxicities. An attractive alternative approach would be to target proteins, such as vinculin, that associate with the integrin cytoplasmic domains and regulate its ligand binding properties. Here we report that a novel reagent, denoted vinculin activating peptide or VAP, increases integrin activity from within the cell, as measured by elevated: (1) active integrins on the cell surface, (2) adhesion of cells to extracellular matrix ligands, (3) numbers of cell-matrix adhesions, and (4) downstream signaling. These effects are dependent on both integrins and a key regulatory residue A50 in the vinculin head. We further show that VAP enhances integrin function independent of both its mode of delivery and the melanoma cell type tested. Furthermore, VAP dramatically increases the sensitivity of melanomas to chemotherapy in clonal growth assays and in vivo mouse models of melanoma. Finally, we demonstrate that the increase in chemosensitivity results from increases in p53-dependent DNA damage-induced apoptosis. Collectively these findings demonstrate for the first time that integrin function can be manipulated from within the cell and validate integrins as a new strategy for the treatment of chemoresistant melanomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1535. doi:10.1158/1538-7445.AM2011-1535
Abstract 1537: Role of S100PBP in pancreatic adenocarcinoma
Authors: Lines Kate E. , Audi Namaa , Chelala Claude , Wijesuriya Nilu , Kocher Hemant , Hurst Helen , Crnogorac-Jurcevic Tatjana
Published: June 2012

We have recently discovered a 37kDa novel S100P-binding protein, S100PBP which exhibits no homology to any currently known protein. We have therefore explored its expression in a wide range of normal and cancer tissues, and performed several in vitro functional assays to define its putative roles.

In order to determine S100PBP localization in human samples immunohistochemistry was performed on a multi-organ tissue array (Pantomics) and on an in-house made pancreatic tissue array including normal pancreas, primary cancer and metastatic lesions. To determine S100PBP functions cells with both silenced and stably over-expressing S100PBP were established. Affymetrix gene expression arrays and a battery of functional assays including adhesion, migration and invasion were performed using these cells.

We show that S100PBP is ubiquitously expressed in different normal and tumor specimens in a cell and tissue type dependent manor. In normal pancreas S100PBP is widely expressed in both exocrine and endocrine compartments while in pancreatic adenocarcinoma it is present in early precursor lesions, PanINs, and retained in some cancer cells, but with significantly lower intensity.

We further show that in pancreatic cancer cells S100PBP binds, in addition to S100P, several other S100 proteins, namely S100A2, S100A4 and S100A6 in a calcium-dependant fashion. Over-expression of S100PBP also causes changes in the expression levels of S100P and S100A9, which were both down-regulated, while the levels of the S100A4 transcript increased. Furthermore, manipulation of S100PBP expression leads to phenotypic changes affecting the adhesive, migratory and invasive capacity of pancreatic cancer cells, which varied depending on the cellular context and constellation of presence of different S100 proteins. Both over-expression and silencing of S100PBP also induced an increase/decrease in Cathepsin Z levels, respectively. This protease appears to be critically important for inducing the observed changes in cellular adhesion.

In summary, S100PBP is ubiquitously expressed and modulates the function of several S100 proteins, as well as Cathepsin Z, and appears to play an important role in the adhesive, migratory and invasive capabilities of pancreatic cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1537. doi:10.1158/1538-7445.AM2011-1537
Abstract 1546: CD44 cleavage promotes anoikis resistance in oral squamous cell carcinoma
Authors: Qian Xu , Kamarajan Pachiyappan , Kapila Yvonne Lorraine
Published: June 2012

Background: CD44, a cell surface proteoglycan receptor, plays an important role in modulating oral squamous cell carcinoma (OSCC) cell functions. The recent identification of CD44 as a cancer stem cell marker led us to hypothesize that cleavage of CD44 may alter OSCC cell-matrix interactions and anoikis resistance, and thereby promote a metastatic phenotype in OSCC.

Methods: Anoikis-resistant cells were developed by maintaining human OSCC (UM-SCC 14A) cells under suspension culture conditions in polyhydroxyethylmethacrylate (poly-HEMA) coated plates. Anoikis sensitive control cells were maintained in adherent culture conditions. CD44 cleavage was blocked by the use of matrix metalloproteinase (MMP) chemical inhibitors, including ADAM-17 and ADAM-10. Western blot analysis was used to examine the relative levels of CD44 among the adherent and anoikis-resistant cells.

Results: This study showed that anoikis resistant OSCC cells exhibit higher levels of CD44 cleavage than their adherent counterparts. The study also showed that ADAM-10 and ADAM-17 chemical inhibitors blocked CD44 cleavage and the formation of anoikis-resistant multicellular aggregates in OSCC cells.

Conclusions: CD44 cleavage plays a crucial role in promoting the anoikis resistant phenotype in OSCC cells, suggesting that CD44 may significantly contribute to OSCC tumor initiation and metastasis. (Supported by NIH RO1 DE014429 to YLK)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1546. doi:10.1158/1538-7445.AM2011-1546
Abstract 1558: Paracrine signaling through Mycn enhances tumor-vascular microenvironment in neuroblastoma
Authors: Chanthery Yvan H. , Gustafson W. Clay , Weiss William A.
Published: June 2012

Neuroblastoma, a tumor of peripheral neural crest origin, numbers among the most common childhood cancers. Both amplification of the proto-oncogene MYCN and increased vascular density mark high-risk disease. Since angiogenesis is regulated by phosphatidylinositol-3’ kinase (PI3K), we tested a clinical PI3K inhibitor, NVP-BEZ235, in MYCN-dependent neuroblastoma. NVP-BEZ235 decreased angiogenesis in a primary human neuroblastoma (MYCN-amplified orthotopic xenograft), and improved survival in a transgenic mouse model for MYCN-driven neuroblastoma. Using both gain and loss of function approaches, we demonstrate that the anti-angiogenic efficacy of NVP-BEZ235 was critically dependent on Mycn, in vitro and in-vivo. Thus, clinical PI3K/mTOR inhibitors drive degradation of Mycn in tumor cells, with secondary paracrine blockade of tumor-vascular microenvironment. These observations argue that NVP-BEZ235 should be tested in children with high-risk, MYCN amplified neuroblastoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1558. doi:10.1158/1538-7445.AM2011-1558
Abstract 1563: M402, a heparan sulfate mimetic, inhibits taxane mediated mobilization of endothelial progenitor cells and their homing to tumors in a mouse model
Authors: Schultes Birgit C. , D'Alessandro Josephine S. , Chu Chia L. , Long Alison , Honan Christopher T. , Kishimoto Takashi K.
Published: June 2012

Treatment with certain anti-cancer agents, particularly taxanes and sunitinib, can lead to mobilization of pro-angiogenic factors and an acute mobilization of Endothelial Progenitor Cells (EPCs), which home to the viable tumor rim where they can enhance tumor vascularization. This phenomenon has been linked to rapid tumor regrowth following chemotherapy or treatment with specific angiogenesis inhibitors and may thus diminish the long-term efficacy of the treatment. EPCs are mobilized in response to circulating growth factors and chemokines (VEGFR, FGF, G-CSF, IL-6, SDF1α, etc.) that are induced by the drug or the progressing tumor. Many of these factors contain heparin binding domains for their anchorage to proteoglycans on cell surfaces or the extracellular matrix. We tested a novel heparan sulfate mimetic, M402, for its ability to inhibit EPC mobilization as well as EPC homing to the tumor as a result of interference with heparin-binding cytokines, chemokines and growth factors. In normal BALB/c mice, G-CSF and Docetaxel induced a significant increase in EPC within 8-24 h of dosing as compared to the saline control, while cisplatin or gemcitabine treatment did not show this effect. The docetaxel-induced EPC mobilization into the blood could be inhibited significantly by M402, similarly to an anti-VEGFR2 antibody (DC101). Analysis of the bone marrow microenvironment indicated that M402 does not inhibit the generation of EPCs but rather prevents the mobilization of EPCs from the bone marrow, likely through disruption of the SDF-1α/CXCR4 axis. M402 alone did not influence EPC mobilization in normal mice. However, in mice bearing orthotopic 4T1 breast carcinoma or Capan-2 pancreatic tumors, treatment with M402 normalized circulating EPCs otherwise mobilized by tumor-secreted factors, particularly G-CSF. Furthermore, M402 inhibited homing of EGFP labeled EPCs into SDF-1a loaded matrigel plugs or 4T1 tumors. The effect on EPCs correlated with decreased tumor angiogenesis as assessed by immuno-histochemistry and microCT. Furthermore, we observed synergistic anti-tumor activity of M402 with docetaxel in the 4T1 model. In conclusion, the experiments show that M402 could inhibit docetaxel or tumor-mediated EPC mobilization by trapping the EPCs in the bone marrow and inhibiting their recruitment into the tumor microenvironment. The data provide a scientific rationale for further studying the observed synergy of M402 with taxanes in cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1563. doi:10.1158/1538-7445.AM2011-1563
Abstract 1564: Investigating the interaction of tumor xenografts with their microenvironment by combining human- and mouse- specific assays with high throughput RT-qPCR
Authors: Farren Matthew , Weston Susie , Brown Helen , Powell Steve , Shaw Robert , Smith Neil R. , Lovick Susan , Ashton Susan , Wedge Stephen R. , Barry Simon T.
Published: June 2012

Tumour growth is governed by the interaction with its microenvironment through pathways that regulate tumour cell function, angiogenesis, and recruitment of associated stromal cells and immune infiltrate. These complicated biological networks can be studied in tumour xenografts using a combination of gene expression, protein and histological analysis. The majority of gene expression studies either probe expression of specific transcripts by RT-qPCR, or use broad Affymetrix microarrays to examine 1000s of genes. RT-PCR experiments may be too focussed studying the interaction of a small number of pathways, while Affymetrix is often not sensitive enough to detect low abundance transcripts, or is limited by species specificity of the probe sets. For example studying tumour stromal and endothelial cells can be challenging because these cells comprise only a small proportion of the tumour. In this study we have used high throughput RT-qPCR to specifically analyse 180 human and mouse genes (or orthologues) thought to regulate key stromal/tumour interactions in a broad xenograft panel. This approach enabled us to determine the expression patterns of potential angiogenic, migratory and survival drives of a diverse range of tumour xenograft models. Across the xenograft panel these genes distinguished tumours with an Epithelial and Mesenchymal phenotype. Interestingly we find that the transcript profile of the supporting stroma (all murine transcripts) is similar between models and key genes cluster with physiological characteristics such vessel, stromal or inflammatory phenotypes. We also used this approach to assess pharmacodynamic changes in gene expression in the tumour and host compartments in response to a VEGF signalling inhibitor. Surprisingly there was little modulation in the expression of genes in the tumour cell compartment. However, there was a clear down regulation of transcripts corresponding to endothelial cells with a concomitant reduction in the tumour vasculature. This approach has enabled us to gain insight into pre-clinical models and the response to a host targetted therapy. The data provides information that enhances understanding that can be derived using histological analysis and standard protein expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1564. doi:10.1158/1538-7445.AM2011-1564
Abstract 157: Variability of microRNA measurements in breast ductal carcinomas
Authors: Grizzle William E. , Kerr Elizabeth H. , Parker Suzanne B. , Oelschlager Denise K. , McNally Lacey R.
Published: June 2012

MicroRNAs (miRNAs) are a newly identified class of molecules involved in the post transcriptional regulation of genetic information. Multiple approaches have been developed to measure miRNAs including the measurement of miRNAs in paraffin embedded tissue. There have been few reported studies of the reproducibility of miRNA measurements, especially in paraffin embedded tissues, and how such measurements might vary due to tissue heterogeneity and/or analytical variability. We used microdissected paraffin embedded samples of ductal carcinoma of the breast enriched to a tumor nuclear cellularity of at least 80% to determine the reproducibility of analysis of miRNAs extracted from paraffin sections. From each of 3 microdissected paraffin embedded tissues, six 10μ paraffin sections were cut and combined as one specimen and the following six 10μ sections were combined as a second specimen from the same case. While the sections were adjacent, this would incorporate variation due to tissue heterogeneity over 0.12mm of the specimen that was analyzed. All six specimens were blinded and 1500 miRNAs including miRNAs from mice, rats and plants as controls were analyzed by High Throughput Genomics (HTG) considering each of these 6 specimens as an independent specimen. Even with tissue heterogeneity, the correlations of the values of miRNA of the three pairs of specimens were 0.96, 0.90 and 0.83; the 12 correlations between specimens of different cases did not excel 0.9 and only 2 exceeded 0.8. Results of combining alternative paraffin sections into 2 specimens from these same cases and laser capture microdissection specimens are pending to separate differences due to variation in tissue from analytical variables. Of note, the 22 most upregulated miRNAs (X20 to X30 basal levels) in these breast ductal carcinomas include the following: Let 7b, Let 7f, 1225-3P, 1228, 1237, 1280, 1281, 1308, 16, 1826, 191, 200c, 23a, 27a, 574-5p, 638, 663b, 720, 768-3P, 768-5P, 886-5P, and 92a. These studies are continuing and laser capture microdissection results will be incorporated in the study.

Supported in part by the Breast SPORE at UAB (CA089019-09) and a grant from the Susan G Komen foundation (BCTR0600484).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 157. doi:10.1158/1538-7445.AM2011-157
Abstract 1579: TGF-β blockade controls ascites by preventing abnormalization of lymphatic vessels in orthotopic human ovarian carcinoma model
Authors: Liao Shan , Liu JieQiong , Jain Rakesh K. , Xu Lei
Published: June 2012

Ovarian cancer is characterized by the rapid growth of solid intraperitoneal tumors and accumulation of ascites, the ascites being the clinical presentation of end-stage disease. The role of Transforming Growth Factor beta (TGF-β) in tumor progression has been well studied. However, the role of TGF-β in lymphatic vessel function remains far from understood. We study the effect and mechanisms of TGF-β blockade in human ovarian cancer. We report that blocking tumor and host TGF-β signaling can significantly inhibit the growth of both VEGF- and IL-8-dependent human ovarian tumors. More importantly, we have shown that TGF-β blockade significantly decreases the volume of ascites by both inhibiting ascites formation and preventing impairment of lymphatic vessel drainage, thus demonstrating its potential as a promising new treatment for malignant ascites. Since a number of agents that target the TGF-β-pathway are in clinical trials, the results of the proposed study could be rapidly translated to the clinic.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1579. doi:10.1158/1538-7445.AM2011-1579
Abstract 158: Expression of miR-205 is significantly associated with prognosis of endometrial cancer
Authors: Karaayvaz Mihriban , Zhang Cecilia , Mehmood Saira , Georgakopoulos Penelope , Burke Stephanie , Shroyer Kenneth , Liang Sharon , Ju Jingfang
Published: June 2012

Background: microRNAs (miRNAs) have emerged as key regulators of gene expression, and their altered expression has been associated with tumorigenesis and tumor progression. As a result, miRNAs represent important diagnostic biomarkers for the advancement of cancer and potential therapeutic approaches. They may be up-regulated or down-regulated in various tumor types, thus act as oncogenes or tumor suppressors. Although accumulating evidence suggests the role of aberrant miRNA expression in endometrial carcinogenesis, there is still limited data available about the endrometrial miRNAs. Endometrial cancer is characterized by frequently infiltrating tumors, and one of the most important molecular alterations in this process is through epithelial-mesencymal transition (EMT). Several studies implicated the role of miRNAs targeting the critical players during EMT. The goal of this study is to investigate the clinical utility of selected key miRNAs in archival FFPE tissue samples of patients with endometrial cancer. In this study, the expression of miR-26a, miR-205, miR-200c, miR-192, miR-215, let-7g, miR-21, miR-181b were quantified from 20 stage I, 2 stage II, 5 stage III, 8 stage IV endometrial cancer patients (endometrioid-type endometrial cancer (EEC), endometrial serous carcinoma(ESC), clear cell carcinoma(CCC) undifferentiated carcinoma (UDC), malignant mullerian mixed tumor (MMMT)) with up to 15 years clinical follow up information.

Methods: Using archival FFPE tissues, areas of tumor and normal tissues were identified according to the corresponding hematoxylin and eosin stained sections, and cores of 1.5 mm in diameter were extracted. Total RNAs were isolated from 35 paired endometrial tumor and adjacent normal tissue specimens by using Trizol based approach. The expression levels of miRNAs were quantified by using real-time qRT-PCR analysis.

Results: The expression of miR-205 (p=0.0002) and miR-200c (p<0.0001) were significantly elevated in endometrial cancer tissue specimens when compared to adjacent normal tissues. Kaplan-Meier survival analysis indicated that low levels of miR-205 expression (hazard ratio, 0.309; log rank test, p=0.018) is closely associated with better patient's overall survival.

Conclusions: miR-205 holds a great potential as a prognostic biomarker in endometrial cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 158. doi:10.1158/1538-7445.AM2011-158