bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1127: Bcr-Abl inhibition in leukemia cells creates metabolic addictions
Authors: Alvarez-Calderon Francesca , Zaberezhnyy Vadym , Gemta Lelisa , Gregory Mark A. , DeGregori James V.
Published: August 2012

Bcr-Abl kinase inhibitors are the standard therapy for chronic myelogenous leukemia (CML). While effective in controlling disease in chronic phase, these inhibitors often fail to completely eliminate Bcr-Abl+ CML cells and also fail to achieve durable remissions for advanced CML and Bcr-Abl+ acute lymphoblastic leukemias (ALL). Our lab employed a large-scale synthetic lethal shRNA screen to identify genes involved in CML survival upon treatment with the Bcr-Abl kinase inhibitor imatinib (IM) [Cancer Cell. 2010;18(1):74-87]. This screen identified several genes involved in energy utilization including a component of pyruvate dehydrogenase, dihydrolipoyllysine-residue acetyltransferase. CML proliferation depends on Bcr-Abl-driven glycolysis for energy production. Upon IM treatment, we hypothesized that these cells are forced to rely on other sources of energy including the TCA cycle and the electron transport chain, and that targeting alternative energy production pathways will enhance IM-mediated elimination of CML cells. Thus, we predicted that inhibition of mitochondrial respiration by knockdown or pharmacologic inhibition would cooperate with tyrosine kinase inhibitors (TKI) to eliminate Bcr-Abl+ leukemia. Indeed, our experiments have shown that knocking down pyruvate dehydrogenase in human blast crisis Bcr-Abl+ CML cells (K562) greatly sensitized cells to IM in vitro. Conversely, supplementing the cell culture media with increasing concentrations of methyl-pyruvate protected K562 cells from IM treatment. Moreover, we found that the mitochondrial ATP-synthase inhibitor Oligomycin A (OA) also synergized with IM to kill CML cells in vitro. Interestingly, the doses of OA are far below the IC50 and do not affect the oxygen consumption rates, indicating that mitochondrial respiration is not inhibited. These OA doses alter mitochondrial transmembrane potential and increasing superoxide levels. In addition, OA enhanced elimination of Bcr-Abl+ cells by a Bcr-Abl TKI in vivo and prolonged disease-free survival in a mouse model of Bcr-Abl+ B-ALL. Notably, drug doses of OA used had no apparent adverse effects on these mice. Targeting mitochondrial metabolism as an adjuvant drug therapy may prevent the survival of residual Bcr-Abl+ CML cells upon tyrosine kinase inhibitor treatment. This project is supported by pre-doctoral fellowship number F31CA157166 from the National Cancer Institute, and Leukemia and Lymphoma Society Grant

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1127. doi:1538-7445.AM2012-1127
Abstract 1146: A functional polymorphism on chromosome 15q25 associated with survival of early stage non-small cell lung cancer
Authors: Choi Yi Young
Published: August 2012

Introduction: The 15q25 region was associated with lung cancer risk and might be associated with prognosis of lung cancer. This study was conducted to determine the impact of a functional polymorphism in the CHRNA3 gene on chromosome 15q25 on the survival of patients with early stage non-small cell lung cancer (NSCLC). Methods: Five hundred eighty-three consecutive patients with surgically-resected NSCLC were enrolled. The rs6495309C>T polymorphism in the promoter of the CHRNA3 gene was investigated. The association between genotype and overall survival and disease-free survival was analyzed. Results: Patients with the rs6495309 CT or TT genotype had a significantly better OS and DFS than the rs6495309 CC genotype (adjusted hazard ratio for overall survival = 0.56, 95% confidence interval = 0.41-0.75, P = 0.0001; and adjusted hazard ratio for disease-free survival = 0.61, 95% confidence interval = 0.48-0.79, P = 0.0001). An association between the rs6495309C>T polymorphism and survival outcome was demonstrated in smokers and never-smokers, and in squamous cell carcinomas and adenocarcinomas. Conclusion: The CHRNA3 rs6495309C>T polymorphism may affect survival in patients with early-stage NSCLC. Analysis of the rs6495309C>T polymorphism can help identify patients at high risk of a poor disease outcome. Key words: CHRNA3, polymorphism, non-small cell lung cancer, survival

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1146. doi:1538-7445.AM2012-1146
Abstract 115: KIR haplotype polymorphism determines innate susceptibility/resistance to childhood leukemia
Authors: Samarani Suzanne , Nocq Julie , Allam Ossama , Marzouk Rim , Momparler Richard.L , Ahmad Ali
Published: August 2012

Background: The Killer-cell Immunoglobulin-like Receptor (KIR) genes encode receptors that are expressed on the surface of Natural Killer (NK) cells and a subset of T cells. The receptors regulate functional activities of these immune cells in the body. There exist seventeen distinct KIR genes in humans of which nine encode inhibitory, and six encode activating receptors, while two are pseudo genes. KIR haplotypes show extensive variability with respect to their repertoire of activating KIR genes. Humans may have none or up to six different activating KIR genes. The acquisition of these genes is believed to decrease activation threshold of NK cells in humans, and provide resistance to malignancy. Hypothesis: We hypothesized that the acquisition of activating KIR genes by an individual may protect him/her from childhood leukemia. Methods: We used the candidate gene approach. In a case-control study, we determined the presence or absence of different activating KIR genes using gene-specific primer pairs. The frequencies of each gene were compared between cases and controls using Chi2 test and multivariate logistic regression. Results: Our results show for the first time that the inheritance of activating KIR genes is associated with increased resistance to childhood leukemia (both B-ALL and T-ALL; in adjusted analysis p-values being as low as 1.14x10-7). Interestingly, this resistance increased as the number of activating KIR genes increased in the genome of the individual. Furthermore, we found that that this resistance/susceptibility is differentially modulated by co-inheritance of different inhibitory KIR-MHC class I gene pairs. Conclusions: The inheritance of activating KIR gene-containing haplotypes confers innate resistance to childhood leukemia. These receptors may serve as novel target molecules for therapeutic interventions in childhood leukemia. The study was supported by a research grant (≠2010-700554) from the Canadian Cancer Society Research Institute (CCSRI).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 115. doi:1538-7445.AM2012-115
Abstract 1151: cMYC amplification in colon cancer: A novel association with BRAF V600E and proficient DNA mismatch repair
Authors: French Amy J. , Sargent Daniel , Foster Nathan , Kabat Brian , Blair Hilary , Limburg Paul , Vierkant Robert , Wang Alice , Tillmans Lori , Thibodeau Stephen
Published: August 2012

Background: Colon cancer is categorized by the acquisition of a number of molecular alterations in both oncogenes and in tumor suppressor genes. Although cMYC alterations have been reported in colon cancer cell lines, little other information exists in primary colon tumors. We sought to determine the frequency of cMYC amplification in primary colon cancer and its relationship to other well defined colon tumor alterations. Methods: An initial set of 392 tumors were evaluated. All samples were tested for the BRAF V600E mutation and all were classified as proficient mismatch repair (pMMR) based on both IHC and microsatellite analysis of tumor tissue. A second set of 522 tumors was selected to replicate associations identified in the first set of samples. Similar to the initial cohort, both the BRAF V600E and the mismatch repair status of the tumors were assessed. The second cohort, however, included tumors that were both pMMR and dMMR. In both sets of samples, fluorescent in situ hybridization was used to evaluate cMYC gene amplification. Results: In cohort 1, cMYC amplification was observed in 15 of the 362 (4%) pMMR tumors successfully analyzed (Table 1). cMYC amplification was detected in 10 of 323 (3%) tumors with normal BRAF status vs. 5 of 39 (13%) tumors with altered BRAF status (p=0.015). In the second cohort, cMYC amplification was found in 20 of the 522 (4%) tumors. Only 1 of the 152 (<1%) dMMR tumors had cMYC amplification vs. 19 of the 370 (5%) pMMR tumors (p=0.012). Of the pMMR tumors, cMYC amplification was detected in 13 of 333 (4%) tumors with normal BRAF status vs. 6 of 37 (16%) tumors with altered BRAF status (p=0.007), nearly identical to the first group. Conclusion: cMYC amplification in colon cancer is an infrequent event. However, when present, cMYC amplification occurs almost exclusively in tumors that are pMMR. Additionally, among pMMR tumors, cMYC amplification is associated with the presence of the BRAF V600E mutation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1151. doi:1538-7445.AM2012-1151
Abstract 1152: Clinical relevance of elevated microsatellite alterations at selected tetranucleotide repeats in colorectal adenocarcinomas
Authors: Katkoori Venkat R. , Shanmugam Chandrakumar , Sthanam Meenakshi , Callens Tom , Messiaen Ludwine M. , Bumpers Harvey L. , Manne Upender , Birdsong George G. , Samuel Temesgen
Published: August 2012

Purpose: Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) are frequently observed in various cancers, including colorectal cancers (CRCs). The incidence of EMAST and its clinical relevance with respect to patient race, however, have not been studied. Therefore, we assessed the frequency and clinical relevance of EMAST and microsatellite instability (MSI) in African-American (AA) and non-Hispanic Caucasian (NHCA) CRC patients. Methods: We analyzed 166 CRCs, collected from the University of Alabama at Birmingham and Grady Memorial hospitals. The EMAST and MSI status of the CRCs was evaluated using seven tetranucleotide microsatellite markers (MYCL1, D8S321, D9S242, D9S747, D20S82, D20S85, L17686) and five National Cancer Institute-recommended MSI markers (BAT25, BAT26, D2S123, D5S346, D17S250). This was accomplished by polymerase chain reactions using marker-specific primers. The status for EMAST and MSI was considered positive if at least two EMAST- or MSI-specific loci were found to be unstable. The EMAST and MSI phenotypes were correlated with clinicopathologic features and patient survival. Results: The overall incidence of EMAST was 46% (77 of 166 cases); AA patients had a higher incidence (62 of 124, 50%) relative to NHCA patients (15 of 42, 36%). Analyses based on tumor location and patient race showed that, for AAs, EMAST was more common in colonic tumors (60 of 114, 53%) than in tumors of NHCAs (10 of 32, 31%). In contrast, only 20% of rectal tumors in AAs (2 of 10) demonstrated EMAST, as compared to NHCA (5 of 10, 50%) patients. Combined analysis (both racial groups) showed that 16% (26 of 166) of cases exhibited both EMAST and the phenotype, MSI-high. Furthermore, for AA patients, but not NHCA patients, EMAST was associated with mucinous CRCs (χ2p = 0.02 and χ2p = 0.56, respectively). NHCA patients who had EMAST had lower median survival (24 months) relative to those without EMAST (55 months). In contrast, the AA patients did not demonstrate an appreciable difference in median survival. Conclusions: These findings suggest that, for AA patients, CRCs with EMAST are associated with the MSI-high phenotype and mucinous tumors. For NHCA patients, EMAST is associated with short survival. This work was supported by grants from the NCI/NIH (2U54-CA118948, R01-CA98932, and R03-CA139629).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1152. doi:1538-7445.AM2012-1152
Abstract 1161: The role of MED12 exon 2 mutations in histopathological variants of uterine leiomyoma
Authors: Mäkinen Netta , Arola Johanna , Vahteristo Pia , Lehtonen Heli J. , Bützow Ralf , Aaltonen Lauri A.
Published: August 2012

Uterine leiomyomas, or fibroids, are benign tumors affecting millions of women worldwide. They arise from the overgrowth of smooth muscle and connective tissue. Regardless of their benign nature, leiomyomas can cause considerable morbidity, such as abdominal pain, excessive bleeding, pregnancy complications and even infertility. They also pose a considerable socio-economic impact and are the most common cause for hysterectomy. Based on histopathology, uterine leiomyomas can be divided into various subtypes. Cellular, atypical and mitotically active fibroids are examples of relatively rare variants of common leiomyomas. Rarely, fibroids may undergo malignant transformation and develop into a leiomyosarcoma. We recently showed that MED12 (mediator complex subunit 12) exon 2 is mutated in approximately 70% of uterine leiomyomas (ref 1). The mutation hot spot affects an evolutionary conserved region of the MED12 protein. MED12 is part of a 26-subunit protein complex, which is thought to regulate global as well as gene-specific transcription by bridging DNA regulatory elements to the RNA polymerase II initiation complex. To study the frequency of MED12 exon 2 mutations in different histopathological variants of uterine leiomyoma, we analyzed 105 fibroids and 61 leiomyosarcomas by direct sequencing. Both rare histopathological variants and leiomyosarcomas harbored significantly less MED12 exon 2 mutations than common leiomyomas. The driver mutations underlying these lesions remain to be characterized. (1) N Mäkinen et al. (2011) MED12, the mediator complex subunit 12 gene, is mutated at high frequency in uterine leiomyomas. Science 14, 252-255.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1161. doi:1538-7445.AM2012-1161
Abstract 1162: SIX1 protein expression selectively identifies blastemal elements in Wilms tumor
Authors: Sehic Daniel , Karlsson Jenny , Sandstedt Bengt , Gisselsson David
Published: August 2012

Background. Wilms tumour (WT) is the most common renal neoplasm in children. Histologically, most WTs consist of three tissue elements: blastema, epithelium, and stroma. Some cases also show diffuse or focal anaplastic features. Previous studies have shown that a predominance of blastemal cells in post-chemotherapy WT specimens is associated with a poor clinical course. However, there is currently no molecular marker for blastemal cells, and risk stratification for post-nephrectomy treatment is therefore often based on clinico-histological parameters alone. Procedure. In the present study, three public gene expression microarray datasets, including 82 WTs and 8 normal foetal kidneys, were used to establish a consensus gene expression profile of WT. By bioinformatic analyses, 17 genes overexpressed in WT compared to foetal kidney were then selected for evaluation of their protein expression in WT cell lines and in the different histological components in paraffin-embedded WT tissue sections by immunofluorescence. Results. Most of the evaluated proteins were expressed in all three common histological components. A prominent exception was SIX1, being expressed predominantly in blastemal elements in 24/25 paediatric cases containing blastema. Anaplastic elements exhibited highly variable SIX1-positivity. The SIX2 protein, known to be co-expressed with SIX1 during nephrogenesis, only exhibited blastemal-predominant expression in half of the SIX2 evaluated cases. Conclusions. Genes highly expressed in WT compared to foetal kidney are generally overexpressed in all of the three common WT tissue elements. An exception is the predominant expression of SIX1 in blastemal cells, hereby identifying this protein as a candidate marker for blastema.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1162. doi:1538-7445.AM2012-1162
Abstract 1164: MTUS1 as a potential progression marker at chromosome 8p in bladder cancer
Authors: Rogler Anja Paola , Hoja Sabine , Ekici Arif , Wullich Bernd , Goebell Peter , Hartmann Arndt , Stöhr Robert
Published: August 2012

Aims and background: The search for sensitive and specific progression and recurrence markers in bladder cancer is a major focus of many urological research groups. The aim of this study was to identify biomarkers on chromosome 8p in papillary urothelial carcinoma that give evidence for progression from non-invasive pTa to invasive pT1 stage. Candidate genes should be analyzed functionally in cell lines and validated immunohistochemically using tissue micro arrays. Material and methods: To find new progression markers 19 papillary urothelial carcinomas (9 pTa and 10 pT1) were investigated with array comparative genomic hybridization (aCGH) on Affymetrix Genome-Wide Human SNP Array 6.0. Therefore, tumor slides were manually microdissected, genomic DNA was isolated and DNA was hybridized on Affymetrix Chip together with reference DNA from 167 tumor-free patients. Computational analysis was performed with free Software “Genotyping-Console” from Affymetrix. MTUS1 gene and protein expression were investigated in bladder cancer cell lines and tumor tissue using qRT-PCR, Western blot and immunohistochemistry. Results: aCGH revealed more chromosomal aberrations overall as well as more deletions on chromosome 8p in pT1 tumors (50%) compared to pTa tumors (11%). Several putative progression-associated genes could be identified on 8p, for example SLC7A2, PDGFL, MTUS1, FGL1 and PCM1. MTUS1 (microtubule associated tumor suppressor 1) was chosen for further analysis, as in other tumor types this gene is known to be associated with frequent loss of heterozygosity at 8p22. However, to our knowledge, not much is known about its role in bladder cancer. Western blot analysis revealed expression of different isoforms in cell lines (140, 80 and 60 kDa) and tumor tissue (mainly 80kDa). Immunohistochemical staining of 128 papillary and 236 advanced tumors showed conflicting results compared to the aCGH findings. Conclusion: Whereas loss of genetic material at 8p22 harboring the MTUS1 gene is significantly associated with a pT1 stage in papillary urothelial carcinoma, pT1 tumors showed a significantly higher MTUS1 expression than pTa tumors as was shown by immunohistochemistry. At least in the pT1 group, expression loss contributed to worse overall survival, suggesting MTUS1 as a prognostic marker. Functional effects of MTUS1 overexpression will be analyzed in the future in RT112 cell line.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1164. doi:1538-7445.AM2012-1164
Abstract 1171: Identification of p53 target genes by ChIP-Seq and transcriptome analysis combined with genome-wide p53-binding motif analysis in silico
Authors: Idogawa Masashi , Sasaki Yasushi , Shinomura Yasuhisa , Imai Kohzoh , Tokino Takashi
Published: August 2012

p53 is one of the most important tumor suppressor genes. In approximately half of all human cancers, p53 is inactivated as a direct result of mutations in the p53 gene. Furthermore, mutation or deletion of p53 is related to poor prognosis and resistance to chemotherapy and radiation. The activation of p53 is induced by a variety of cell stresses, such as DNA damage, oncogene activation, spindle damage and hypoxia. Activated p53 transactivates a number of genes, many of which are involved in DNA repair, cell cycle arrest and apoptosis. In this study, we tried to identify novel p53 target genes by the combination of chromatin-immunoprecipitation, transcriptome analysis and a search of p53 binding motif in silico. We infected lung cancer cell, H1299 (p53 null) with adenovirus vectors expressing FLAG-tagged p53, p63g and p73b, and then performed chromatin-immunoprecipitation (ChIP) with FLAG antibody. The immunoprecipitated DNA was subjected to next-generation sequencing (ChIP-Seq). The short sequences generated by ChIP-Seq were aligned to the human genome sequence and peaks which indicate the binding of p53 family protein were detected by several algorithms. We also searched p53 binding motif, RRRCWWGYYY appeared inside genes and 10k base upstream from its transcription start site, and selected ChIP-Seq peaks of which genomic positions include p53 binding motif. Furthermore we analyzed mRNA expression of H1299 cells by cDNA microarray including several long intergenic non-coding RNAs (lincRNAs) and next-generation sequencing (RNA-Seq). We combined three categories of data, mRNA expression, ChIP-Seq peaks and p53 binding motif in silico. As a result, we found several genes which are upregulated by p53 family proteins and have ChIP-Seq peaks with p53 binding motif in promoter regions or gene bodies. These genes included not only well-known p53 target genes such as p21 and MDM2 but also novel candidate genes. In addition, ChIP-PCR and reporter assay confirmed the binding and responsiveness to p53. Thus, our approach identified several novel target genes induce by p53. We are now analyzing the role of these genes in p53 response pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1171. doi:1538-7445.AM2012-1171
Abstract 1178: Allele specific p53 mutant synthetic lethality
Authors: Yu Xin , Vazquez Alexei , Levine Arnold J. , Carpizo Darren R.
Published: August 2012

Rescuing the function of mutant p53 is an attractive cancer therapeutic strategy. The NCI60 database has reported the growth inhibition of over 47,000 compounds in a panel of 60 human tumor cell lines with the p53 mutational status known. We hypothesized that we could use the NCI60 dataset as an “in silico” screen to identify compounds with activity in cell lines containing mutant p53. We identified three compounds from the thiosemicarbazone family and validated this methodology for two of the three. Both compounds demonstrate a marked sensitivity in cell lines carrying a p53-175 allele while at the same time are relatively nontoxic to cells wildtype for p53. Mechanistic studies reveal that one of the compounds restores a wildtype structure and function to the p53-175 mutant. These findings extend to p53R172H knock-in mutant mice as well as to the inhibition of xenograft tumor growth in a 175-allele specific, mutant p53 dependent manner. Together these data both validate a bioinformatics approach to the identification of compounds with activity in cell lines expressing mutant p53, and identify two compounds that demonstrate allele specific mutant p53 synthetic lethality.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1178. doi:1538-7445.AM2012-1178
Abstract 1185: Plakoglobin (β-catenin) interacts with the transcription factor p53 and regulates the expression of genes involved in tumorigenesis and metastasis
Authors: Aktary Zackie , Pasdar Manijeh
Published: August 2012

Plakoglobin (β-catenin) and β-catenin are highly homologous proteins that function in cell-cell adhesion and signaling. Both proteins exist in a cadherin-associated form, which mediates adhesion, and in a distinct cytosolic/nuclear form, which plays a signaling role. Despite their interactions with common cellular partners, β-catenin has well documented oncogenic potential while plakoglobin expression is generally associated with tumor/metastasis suppression. The underlying mechanisms for this activity of plakoglobin are unclear. We previously showed that plakoglobin expression in oral squamous carcinoma cells (SCC9-PG) resulted in a mesenchymal-epidermoid transition, which was concurrent with increased N-cadherin and decreased β-catenin levels. Comparison of the RNA and protein profiles of SCC9 cells and SCC9-PG transfectants identified a number of differentially expressed proteins and transcripts, which suggested that plakoglobin regulates gene expression. Closer analysis of the mRNA profiles of SCC9 and SCC9-PG cells identified several p53 target genes that were differentially expressed upon plakoglobin expression, suggesting that plakoglobin may regulate gene expression in conjunction with p53. Here, we describe the ability of plakoglobin to regulate three potential p53 target genes: the tumor and metastasis suppressors 14-3-3α and Nm23 and the tumor promoter SATB1. We show, by RT-PCR and Western blot, that plakoglobin expression results in increased 14-3-3σ and Nm23 and decreased SATB1 mRNA and protein levels. Co-immunoprecipitation experiments show that plakoglobin and p53 interact, and that these interactions occur in both the cytoplasm and the nucleus. Chromatin immunoprecipitation and Electrophoretic mobility shift assays (EMSA) indicate that plakoglobin and p53 associate with the promoters of these target genes. Finally, luciferase reporter assays confirm that plakoglobin regulates the expression of these p53 target genes. Taken together, the results of these studies provide strong evidence that plakoglobin plays an active role in regulating gene expression, a function that has not often been associated with plakoglobin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1185. doi:1538-7445.AM2012-1185
Abstract 132: MicroRNA expression profiling in tumorigenic prostate cancer cells and tumor suppressive functions of let-7
Authors: Liu Can , Kelnar Kevin , Vlassov Alexander , Brown David , Tang Dean
Published: August 2012

Most human tumors contain a small population of cells with stem cell properties, called cancer stem cells (CSCs), which are believed to be responsible for tumor initiation, metastasis, resistance to clinical therapy and relapse. It's crucial to understand the regulatory mechanisms unique to CSCs, so that we may design CSC-specific therapeutics. Recent discoveries of microRNA (miRNA) have provided a new avenue in understanding the regulatory mechanisms of cancer. In our previous studies, we have showed miR-34a under-expression in prostate CSC populations, and its critical role in negatively regulating prostate tumor development and metastasis. However, detailed profiling process was not presented due to space limit. Here, we presented the detailed miRNA expression profiling process and results, together with functional studies of let-7. By quantitative RT-PCR, we dicovered miRNA expressions profiles specific to the prostate cancer (PCa) stem/progenitor populations, i.e., CD44, CD133, α2β1 and side population from thee prostate xenograft models (LAPC9, LAPC4, and Du145). Functional annotation of let-7, one of the commonly under-expressed miRNAs in PCa stem/progenitor populations, showed that over-expression of let-7 inhibited proliferation and clonal expansion of prostate cancer cells in vitro. In addition, over-expression of let-7 by a lentiviral vector suppressed tumor development in mice. To further understand how these miRNAs are differentially expressed in the stem/progenitor population of PCa cells, we took miR-34a as an example, and explored p53 and c-Myc regulation in the CD44+ and CD44- populations, but failed to draw a connection.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 132. doi:1538-7445.AM2012-132
Abstract 1323: Liver-specific knockout mice and liver-derived cell lines provide insights into potential roles for the GP73/GOLM1 HCC serum biomarker - association with sustained cell proliferation
Authors: Arora Gunisha , Flores Rosalba , Wright Lorinda , Fimmel Claus J. , Bode Barrie P.
Published: August 2012

Golgi Protein-73kDa (GP73/GOLM1) is a resident cis Golgi Type II membrane protein that is nearly undetectable in normal liver, but whose expression is upregulated in hepatocellular carcinoma (HCC) and whose circulating levels increase in the plasma of patients with chronic liver disease and HCC. As such, it is the subject of ongoing clinical trials investigating its use as a serum biomarker for HCC. GP73/GOLM1 is cleaved by a proprotein convertase and secreted by proliferating cells, an activity possibly elevated in cancer, yet its biological role in the liver and in the pathogenesis of HCC remains unclear. In order to investigate possible biological roles for GP73/GOLM1, liver-specific knockout mice (C57BL/6) were generated using the Cre-loxP system, characterized by a “floxed” GOLM1 gene and Cre recombinase driven by the albumin promoter. GP73/GOLM1 Cre+/−genotypes were confirmed by PCR analysis. GP73/GOLM1Fl/Fl/Cre(+) animals showed no obvious biological phenotype compared to their Cre(-) littermates, and exhibited normal growth, behavior, and successful mating, suggesting that hepatic GP73/GOLM1 is not vital for normal physiological function, as might be hypothesized from its normally low expression in the liver. Previous studies indicated that GP73/GOLM1 expression was not upregulated in post-hepatectomy liver regeneration, suggesting that its activated expression in the liver is linked to inflammatory or carcinogenic processes rather than transiently increased mitosis. Examination of GP73/GOLM1 expression in 14 human HCC cell lines revealed similar expression levels in epithelial and mesenchymal cell lines, and in an SV40-transformed nontumorigenic human liver epithelial cell line. Rodent in vitro models of hepatocellular transformation revealed equal GP73/GOLM1 expression levels in nontumorigenic parent cell lines and their transformed tumorigenic derivatives. Collectively, the data from the in vivo and in vitro models thus far do not support a direct association of GP73/GOLM1 expression with liver mitogenesis or differentiation, but rather suggest that its expression may be linked to a sustained commitment to cell proliferation - such as occurs in cell lines, liver disease and cancerous transformation, promoted by an inflammatory microenvironment. Possible mechanistic roles for GP73/GOLM1 in HCC development and progression are currently being tested in carcinogenesis models with liver-specific knockout mice. A website on GP73/GOLM1 has also been established as a resource for the research community interested in the study of this protein.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1323. doi:1538-7445.AM2012-1323
Abstract 1339: The role of TNF-α in PGE2-induced tumorigenesis in gastric cancer mouse model
Authors: Oshima Hiroko , Ishikawa Tomo-o , Oshima Masanobu
Published: August 2012

Accumulating evidence has indicated that chronic inflammation is associated with cancer development. Mouse genetic studies have shown that the proinflammatory mediator, PGE2, plays an essential role in gastrointestinal tumorigenesis. Moreover, the proinflammatory cytokine TNF-α also plays a key role in tumorigenesis, including colitis-associated colon cancer. However, the relationship between PGE2 and TNF-α in tumorigenesis has not yet been fully investigated. We previously constructed a gastric tumor mouse model, Gan mice, that recapitulates human intestinal-type gastric cancer, in which both the PGE2 pathway and Wnt signaling are activated simultaneously in the stomach by transgenic expression of the COX-2, mPGES-1, and Wnt1 genes. The induction of the PGE2 pathway triggers an inflammatory response in the Gan mouse stomach, and the expression of proinflammatory cytokines and chemokines is induced in gastric tumor tissues. We herein examined the role of TNF-α in the PGE2-induced inflammation-associated gastric tumorigenesis by crossing Gan mice with TNF-α knockout mice. Importantly, the gastric tumorigenesis in the Gan TNF-α (-/-) compound mice was significantly suppressed in comparison to the control Gan mice. Moreover, the β-catenin level decreased significantly in the gastric tumors of Gan TNF-α (-/-) mice, suggesting a role for TNF-α in the promotion of Wnt signaling. Interestingly, inflammatory cells, including macrophages and CD4+ T cells, still infiltrated into the Gan TNF-α (-/-) mouse tumors, and the expression levels of IL-1α and IL-6 were almost the same as those in the control Gan mouse tumors. Accordingly, it is possible that TNF-α is an important tumor-promoting factor for gastric tumorigenesis, although TNF-α is not essential for PGE2-induced inflammation in the stomach. Notably, macrophages in the Gan TNF-α (-/-) mouse tumors lost their expression of the M2 marker CD206. It has been suggested that macrophages polarized to the M2(-like) type are important for tissue remodeling and tumorigenesis. It is therefore possible that TNF-α is required for macrophage polarization to a pro-tumorigenic status, which may be important for Wnt activation and gastric tumor promotion.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1339. doi:1538-7445.AM2012-1339
Abstract 1352: Shp2 is required for CML initiation and maintenance
Authors: Gu Shengqing , Chan Gordon , Neel Benjamin G.
Published: August 2012

Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm (MPN) caused by the constitutively activated BCR-ABL tyrosine kinase. CML progresses from an initial chronic phase, through an accelerated phase, to a final and fatal blast crisis. Current first-line therapy for CML involves tyrosine kinase inhibitors (TKIs) such as imatinib, dasatinib, or nilotinibs. However, TKIs don't completely cure CML, as revealed by low complete molecular response rate and frequent disease relapse upon drug withdrawal. Studies of patient samples and mouse models indicate that this most likely results from lack of dependence of CML stem cells (CML-SCs) on BCR-ABL for survival. It is important to further identify potential targets of CML-SC. Shp2 is a non-receptor protein tyrosine phosphatase involed in RTK, cytokine, and integrine signaling pathways, and is a target of Abl kinase during cell proliferation. It is required for survival and maintenance of normal hematopoietic stem cells (HSCs). In the context of CML, BCR-ABL constitutively phosphorylates Gab2, which then binds to Shp2, resulting in its inappropriate activation of downstream pathways, including the Ras-Erk cascade. Gab2 is required for CML initiation in vivo. We hypothesized that Shp2 is required for CML development from the stem cell level and might be an effective target for treatment of CML. Using our induced Shp2 deletion tools, we found that Shp2 is required for CML initiation and maintenance in a bone marrow transplant model of CML. Moreover, primitive CML cells undergo elevated cell death upon Shp2 knockout. This implicates Shp2 as a potential target for CML therapy in future.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1352. doi:1538-7445.AM2012-1352
Abstract 1367: Characterization of spontaneous metastases in Champions TumorGraft™ models
Authors: Albee Lee D. , Lu Bin , Anderson Nathan , James Meredith , Friedman Jay , Bruckheimer Elizabeth M.
Published: August 2012

Oncology drug development is challenged by an absence of model systems that accurately mimic the full metastatic processes during disease progression. Methods for establishing metastases generally involve orthotopic implantation or intravenous delivery of cell line-based xenografts. These cell line-based models can capture the seeding phase of the metastatic process but do not address the processes involved in remodeling of the extracellular matrix to allow for invasion into nearby tissues or dissemination to distance sites throughout the body via the lymphatic or the circulatory system. Extensive characterization of Champions TumorGraft™ models demonstrates that spontaneous metastasis in our platform may not be a rare event as it has been verified in 8 different models and preliminary data indicates multiple additional occurrences. Further, the capacity for spontaneous metastasis is not indication specific as it has been observed in Champions TumorGrafts derived from patients with multiple cancer types (e.g. ovarian, breast, H&N, and lung). The development and incidence rate of TumorGraft metastasis seems to correlate with the aggressiveness of disease and occurrence of metastases in the patient. For example, 83% of mice implanted with Champions TumorGraft breast cancer model CTG-0033 develop liver and/or spleen metastases. This Champions TumorGraft was derived from a patient with aggressive disease that failed to respond to first and second line treatments, and developed metastases in multiple organs including the liver. In this report, growth rates, metastases formation and molecular characterization in primary subcutaneous Champions TumorGraft models were compared with their corresponding metastatic lesions to identify changes that may correlate with the formation of metastases. Overall, this study further demonstrates that Champions Oncology TumorGraft platform preserves the biological properties of the original human tumor including spontaneous metastatic behavior and is therefore ideal for oncology drug development programs focused on the inhibition of metastases.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1367. doi:1538-7445.AM2012-1367
Abstract 1368: Investigating the tumorigenicity of disseminated tumor cells
Authors: Hall Carolyn S. , Laubacher Barbara , Anderson Amber , Kuerer Henry , Bedrosian Isabelle , Krishnamurthy Savitri , Lucci Anthony
Published: August 2012

Background: Tumor cells that disseminate to the bone marrow (disseminated tumor cells, DTCs) have been identified in 30% of stage I - III breast cancer (BC) patients and independently predict outcome. Because DTCs are a rare, heterogeneous population of cells, little is known regarding their characteristics; such as their clinical significance with regard to disease progression, and targets that can be utilized for their eradication. DTC Identification is typically achieved using antibodies to epithelial cell adhesion molecule (EpCAM), and cytokeratin (CK). However, EpCAM and CK can be down-regulated during epithelial–mesenchymal transition (EMT). To date, no published report has assessed the tumorigenicity of DTCs isolated from patient samples using an in vivo animal model. The purpose of this study was to investigate the tumorigenicity of DTCs in vivo. Methods: Thirteen clinical stage I-III BC patients provided informed consent to participate in an IRB-approved study involving collection of bone marrow at the time of primary surgery. Following Ficoll centrifugation, bone marrow aspirates were cultured using breast cancer stem cell enriching conditions for 21 days. At 21 days, viability of floating cells with high nuclear: cytoplasmic ratios were confirmed with Tryphan blue staining and cytokeratin expression was identified using pan-cytokeratin immunostaining. 200 cells were co-injected with Matrigel into the mammary fat pads (3 mice/patient) of female nude mice. Mice were monitored daily for tumor formation. Results: Viable floating cells with large nuclear: cytoplasmic ratios were observed in 10/13 cases. Both CK+ and CK- DTCs were identified in 8 out of 10 cases, and CK- DTCs only were identified in 2 out of 10 cases. One of the 10 samples was tumorigenic in vivo; all 3 mice injected with this patient's cells developed breast tumors within ≤ 55 days. This sample was obtained from a 40-year old T2N2 patient with a grade 2 estrogen receptor positive, progesterone receptor negative, Her2/neu negative tumor. Interestingly, CK expression was not detected in this patient's cultured cells. Conclusions: DTCs can be isolated and propagated using breast cancer stem cell enriching conditions, enabling the characterization and assessment of DTCs that are in the process of (or have undergone) EMT. In addition, the tumorigenetic potential of DTCs can be assessed on a patient-by-patient basis by employing an in vivo mouse model. Further studies are needed to develop targeted therapies for the eradication of micrometastatic disease in stage I-III BC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1368. doi:1538-7445.AM2012-1368
Abstract 1372: Microvessel proliferation by co-expression of endothelial nestin and Ki-67 is associated with a basal-like phenotype and aggressive features in breast cancer
Authors: Krüger Kristi , Stefansson Ingunn Marie , Collett Karin , Arnes Jarle Birger , Aas Turid , Akslen Lars Andreas
Published: August 2012

Angiogenesis, the formation of new blood vessels from pre-existing ones, is essential in tumour growth and metastasis. Microvessel density (MVD) is the most widely used method for quantification of tumour angiogenesis. We here present a novel angiogenesis marker, microvessel proliferation (MVP) based on a dual immunohistochemical stain of nestin and Ki-67. Nestin is an intermediate filament protein expressed in a variety of undifferentiated cells, including newly synthesized endothelial cells (1-3), and used in this study to stain the vasculature. Proliferating cells were recognized by their Ki-67 positivity, and immature microvessels were recognized by their nestin positivity combined with their morphology. Proliferating microvessels contains endothelial cells co-expressing nestin and Ki-67. Microvessel proliferation was estimated by vascular proliferation index (VPI), the ratio of vessels containing immature proliferating endothelial cells, and the total number of immature vessels. VPI was evaluated in 178 breast cancer tissue sections. High VPI showed significant association to several markers of aggressive breast cancer, including negative estrogen receptor (ER) status (p=0.003), high tumour cell proliferation by Ki-67 (p=0.004), high p53 expression (p=0.001), five immunohistochemical profiles for the basal-like phenotype (odds ratios (OR); range 2.8-6.3), and the triple negative phenotype (TNP)(p=0.040). Concerning the mode of detection, high VPI was three times more likely to be presented in an interval detected breast cancer compared with a screening detected (OR: 3.0, p<0.0005). Both in univariate and multivariate analysis, high VPI was significantly associated with poor survival (p=0.034 and p=0.022, respectively). In conclusion, activated angiogenesis, estimated by microvessel proliferation, is associated with several markers of aggressive breast cancer phenotype, basal-like breast cancer, interval detection, and a significant predictor of prognosis in this series of breast cancer. 1. Lendahl U, Zimmerman LB, McKay RD. CNS stem cells express a new class of intermediate filament protein. Cell. 1990 Feb 23;60(4):585-95. 2. Mokry J, Cizkova D, Filip S, Ehrmann J, Osterreicher J, Kolar Z, et al. Nestin expression by newly formed human blood vessels. Stem Cells Dev. 2004 Dec;13(6):658-64. 3. Mokry J, Ehrmann J, Karbanova J, Cizkova D, Soukup T, Suchanek J, et al. Expression of intermediate filament nestin in blood vessels of neural and non-neural tissues. Acta Medica (Hradec Kralove). 2008;51(3):173-9.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1372. doi:1538-7445.AM2012-1372
Abstract 1376: TIMP-2 inhibits angiogenesis induced by tumor associated myeloid-suppressor cells
Authors: Guedez Liliana , Stetler-Stevenson William G.
Published: August 2012

Among the mechanisms of resistance to cancer treatment is the recruitment by tumors of inflammatory myeloid (CD11b+, Gr-1+) suppressor cells, promoting angiogenesis and tumor progression. Here, we report the effects of tissue inhibitor of metalloproteases(TIMP)-2 on the recruitment of CD11b+, Gr-1+ cells and subsequent suppression of tumor angiogenesis. Previously, we showed that xenografts of A549 cells with up-regulated TIMP-2 demonstrated significant reduction in the number of CD11b+, Gr-1+ cells, expression of VEGF-R2, and αvβ3 as well as reduced angiogenesis. Here, the effect of TIMP-2 on the growth of Luciferase-tagged-A549 cells was tested in vivo using the direct in vivo angiogenesis (DIVA) assay implanted subcutaneously containing 400 nM TIMP-2 or PBS. TIMP-2 decreased A549-cell proliferation in vivo as determined by quantitating bioluminescence emission. Immuno-histochemistry analysis of the tissue in TIMP-2 treated DIVAs demonstrated a drastic reduction in inflammation, fewer CD11b+, Gr-1+ cells were recruited into the TIMP-2 DIVA compared with untreated DIVA controls, as well as significant lower number of angiogenic vessels and invading endothelial cells were seen. Moreover, bone marrow from mice carrying DIVA with TIMP-2-treated A549 cells demonstrated a relative decrease in cell progenitors as compared with PBS treated tumor cells, suggesting that TIMP-2 blocked the release of tumor factors affecting the mobilization of bone marrow progenitors. These findings support TIMP-2 as anti-angiogenesis and anti-inflammatory factor. By targeting tumor-myeloid suppressors cells, TIMP-2 may have a therapeutic utility in the resistance of tumors to angiogenesis inhibitors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1376. doi:1538-7445.AM2012-1376