bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1186: Differences in the levels, localization and DNA binding of p53 in breast cancer cell lines
Authors: Ray Debolina , Murphy Keith R. , Gal Susannah
Published: August 2012

Mutations in the p53 tumor suppressor affect protein accumulation, localization and DNA binding. We undertook to determine these properties of p53 in breast cancer cells and to see how those attributes change following oxidative stress. We analyzed the p53 in 8 different breast cancer cell lines, with either wild-type or mutant p53 protein. By ELISA and western blots, we found that the levels of the p53 protein were generally low for cells carrying wild-type protein and high in cells having a mutation in the TP53 gene. This was contrasted to the case in the HCC2157 cell line which has wild-type p53 but accumulates the protein to high levels. Using biotinylated DNA and streptavidin magnetic beads, we found that wild-type p53 protein from MCF-7 and ZR-75-1 cells binds with different affinity to 12 gene sequences covering several pathways regulated by p53. Treatment of MCF-7 cells with H2O2 caused an increase in this binding affinity. The p53 from the HCC2157 cells and all of the mutant p53 proteins had minimal to weak binding to these sequences even after treatment with H2O2. We also analyzed the phosphorylation of serine 15 on p53 in 4 of the cell lines. The p53 protein from the HCC2157 cells and two other cell lines showed phosphorylated protein at this site, but we found no correlation between that modification and the levels, localization, or binding affinity of the protein. From this and other work, it appears that the mutation status of the TP53 gene alone can not predict the activity of this tumor suppressor since cell lines with the same genetic information do not show the same properties of this protein. We argue that the analysis of DNA binding or transcription activity must be done in order to correlate the functionality of p53 with clinical outcome in tumors.

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 1186. doi:1538-7445.AM2012-1186
Abstract 1308: Achaete-scute homolog 1 (Ascl1) lineage in the lung gives rise to multiple cell types
Authors: Li Yan , Linnoila Ilona
Published: August 2012

Lung contains many highly specialized cells. Type I pneumocytes are responsible for gas exchange, while type II pneumocytes secrete surfactant which prevents alveoli from collapsing. Airways are lined by non-ciliated secretory (Clara) and ciliated cells that eliminate excess mucus and harmful particles, and rare pulmonary neuroendocrine cells (PNECs) which regulate breathing and contribute to carcinogenesis. PNECs have unknown histogenesis but differentiate prior to the other cells. The neural transcription factor achaete-scute homolog 1 (Ascl1) is critical for PNEC development and is associated with stem cell marker expression in normal and neoplastic lung. Hence, we used in vivo lineage and fate tracing strategy to investigate Ascl1-defined cells (ASDCs) during lung development and injury repair. R26R-stop-lacZ (Rosa) reporter mice were crossed with Ascl1-Cre and Ascl1-CreERTM mice, in which the Ascl1 promoter drives the expression of Cre or inducible Cre recombinase, respectively (Battiste et al., Development (2007) 134:285-93). Following recombination, ASDCs and their descendants will be permanently labeled and were further characterized by immunohistochemistry using cellular differentiation markers. Labeled cells in Ascl1-Cre/Rosa mice gave rise not only to PNECs but also to neural, Clara, ciliated, alveolar type I and type II cells. Interestingly, tamoxifen (TM) administration to Ascl1-CreERTM/Rosa dams at embryonic day E9.5 labeled both airway and alveolar cells, while TM injected at E11.5 only labeled airway cells. Moreover, adult Ascl1-CreERTM/Rosa mice were administered TM followed by naphthalene (Nap), which kills Clara cells. It is notable that in addition to PNECs which are resistant to Nap, regenerating Clara cells were now labeled during the injury repair. We conclude that ASDCs are not limited to giving rise to neural cells or PNECs during pulmonary development, but they also contribute to a range of non-neuroendocrine cells such as Clara and ciliated cells as well as alveolar pneumocytes. Further, the lineage participates in injury repair of the airway lining in mature lung. The current Ascl1 lineage study provides a basis for recent studies on mouse small cell lung cancer (Sutherland et al., Cancer Cell (2011) 19:754-64) which suggested that both PNECs and non-neuroendocrine cells such as alveolar type II pneumocytes may serve as progenitors for this very virulent lung cancer type.

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 1308. doi:1538-7445.AM2012-1308
Abstract 1313: Mutually exclusive somatic mutations in WNT pathway medulloblastomas reveal a critical interaction between DDX3X and SMARCA4
Authors: Weeraratne Shyamal D. , Archer Tenley , Pugh Trevor J. , Hargreaves Diana , Yu Furong , Kautzman Amanda , Jones David T.W. , Jaeger Natalie , Tamayo Pablo , Mesirov Jill P. , Pfister Stefan M. , Lichter Peter , Crabtree Gerald , Meyerson Matthew , Pomeroy Scott L. , Cho Yoon-Jae
Published: August 2012

DDX3X is an ATP-dependent RNA helicase that belongs to an extended family of D-E-A-D motif (DEAD-box) containing proteins whose functions have been implicated in key biological processes ranging from RNA transcription and splicing to the regulation of translation initiation. Through whole exome sequencing of 94 primary medulloblasotmas, we have identified DDX3X as one of the most common recurrently mutated genes in medulloblastoma. These mutations predominantly occur in WNT pathway medulloblastomas which concurrently harbor stabilized forms of mutant beta-catenin. Interestingly, we have also identified SMARCA4 mutations in WNT pathway tumors that are mutually exclusive of DDX3X mutations. In addition, two WNT pathway tumors that have neither DDX3X nor SMARCA4 gene mutations have mutations in genes known to encode for direct binding partners of DDX3X and SMARCA4 (EIF3E and ACTL6A, respectively). This mutual exclusivity of DDX3X and SMARCA4 mutations suggests either a direct interaction between the DDX3X and SMARCA4 gene products or an overlap of the biological processes regulated by each. Here we reveal the direct interaction between DDX3X and SMARCA4 in normal physiological conditions and further investigate the impact of somatic mutations in DDX3X and SMARCA4 on this interaction in WNT pathway associated medulloblastomas. Our results point to a critical link between RNA helicases and the SWI/SNF chromatin remodeling complex in WNT/beta-catenin signaling and disease.

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 1313. doi:1538-7445.AM2012-1313
Abstract 1315: An in vivo platform for drug screening in colorectal cancer
Authors: Cho Yong Beom , Hong Hye Kyung , Seo Sun Ae , Choi Yoon-La , Jin Juyoun , Nam Do-Hyun , Ko YoungHyeh , Kim Hee Cheol , Yun Seong Hyeon , Chun Ho-Kyung , Lee Woo Yong
Published: August 2012

We aimed at generating a clinically meaningful in vivo platform for preclinical drug screening in colorectal cancer. Surgical specimens were collected from 143 patients, and 97 carcinomas were engrafted in immunodeficient mouse (tumor take rate 67%). To develop in vivo platform suitable for drug screening, 39 of xenografted carcinomas were selected and expanded satisfactorily in mice with a mean time to reach a size of 1000-1500 mm3 of 90 ± 20 days. In order to validate the similarity of molecular characters between the patient tumor and carcinomas obtained from xenografts, we conducted the mutation status, an expression array, arrayCGH, and other molecular profiling in colon cancer to look at the molecular progression and transition along with primary tumor, metastatic tumor and xenograft model. Histological analysis and the molecular profiles of tumors revealed a high degree of similarity between the patient tumor and xenografted carcinomas. The xenografted tumors maintain their genotypic features of original tumors, suggest that the in vivo platform can be useful for the personalized drug development in colorectal cancers.

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 1315. doi:1538-7445.AM2012-1315
Abstract 1318: Establishment of patient primary colorectal tumor xenograft models for test of anticancer agents
Authors: Liu Changnian , Alsanabani Hani , Zhou Wen , Liu Rong , He Fang , Li Wenwei , Xu Chunpin
Published: August 2012

BACKGROUND Human xenograft tumor models established by transplantation of human tumor cell lines into immunodifficient mice have been routinely used for preclinical test of anticancer agents. But tumor cell lines have a relatively low transplantability, which resulted a limited number of tumor models available for test of novel anticancer agents. Recently, we have developed a large number of patients’ primary colorectal tumor xenograft models by transplanting human fresh colorectal tumor tissues into nude mice, which have been employed for preclinical test of standard clinically used drugs and novel anticancer agents for their chemosensitivity screening. METHODS The fresh colorectal tumor samples were collected from local hospitals. The tumor fragments of 2-3 mm were subcutaneously implanted in the flanks of nude mice by trocar needle. Sixteen tumor fragments were grafted into four mice from one patient tumor tissue (passage 1). The clinically used drugs included 5-FU, irinotecan, oxaliplatin, and avastin. The histology and gene sequensing of the established primary tumor models were analyzed and compared with patients’ original tumors. RESULTS A total of 120 patients’ colorectal tumor samples were implanted into nude mice; and 65 primary tumor models have been established with a tumor taking rates of 54% for the first passage. The tumor taking rates were higher in the later passages ranged from approximately 80-100%. The test anticancer drugs’ therapeutic efficacy was consistent with their clinical findings. The patients’ primary colorectal tumor xenografts from 5 passages retained a similarity in architecture, histopathological morphology, and genomic mutation status to their patients’ original tumors. CONCLUSIONS The patient primary tumor model system can provide a larger number of models for selection of right models for preclinically testing novel agents based on their anticancer mechanism. The primary tumor models retain a similarity in histology and genomic mutation status to their patients’ original tumors. They may predict more relevant clinical response rate and higher correlation with clinical findings than use of traditional xenograft models established from long-term cultured cancer cell lines. Especially, they have advantages for test of target-oriented therapeutics in new drugs development programs.

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 1318. doi:1538-7445.AM2012-1318
Abstract 1320: Over expression of HGF accelerates hepatitis B virus-induced liver carcinogenesis and hastens the malignancy of hepatocellular carcinoma
Authors: Xie Qian , Su Yanli , Dykema Karl , Koaman Julie , Essenburg Curt , Bradley Robert , Iwava Keiichi , Seki Shuhji , Khoo SokKean , Furge Kyle , VandeWoude George F. , Nariyoshi Shinomiya
Published: August 2012

Genetically modified mouse models play important roles in improving our understanding of HGF/MET signaling in liver development, regeneration and in tumor formation. To evaluate the role of HGF/MET in HBV induced HCC, we generated 1) alb-Cre-Metflox/flox mice which lack of MET expression in the liver; 2) a mouse strain over-expressing human HGF (C3HHGF) to determine if MET is required for HCC development and how HGF accelerates HCC malignancy. We show here that overexpression of human HGF in a C3HHGF mouse model induced spontaneous hepatocellular carcinoma (HCC). Such overexpression also accelerated hepatitis B virus (HBV) surface antigen expression in the liver, which in turn selectively promoted the growth of Met-positive hepatocytes and ultimately led to hepatocellular carcinogenesis. We also demonstrate here that HCC in C3HHGF mice presented gene expression patterns highly associated with malignant human HCC. Molecularly, the HCCs of C3HHGF mice had up-regulated VEGF/HGF signal pathways that can be effectively inhibited by pathway inhibitors. We conclude that C3HHGF mouse model can serve as a good tool for studying human HCC, and we suggest that anti-angiogenic therapeutics can be applied for the treatment of HGF-driven HCC.

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 1320. doi:1538-7445.AM2012-1320
Abstract 1329: Personalizing gastrointestinal cancer treatment by the utilization of TumorGraft™ technology
Authors: James Meredith , Bruckheimer Elizabeth , Morris Ronnie , Rowinsky Eric , Sidransky David , Paz Keren
Published: August 2012

Malignancies of the lower gastrointestinal (GI) tract share similarities in their symptoms, histology, genetic composition and sites of metastasis, but differ in their incidence rates. While colorectal cancer is common with over 130,000 new cases annually in the US alone, small intestinal adenocarcinoma is relatively rare with only 2500 new cases annually. Nevertheless, the overall clinical benefit of “standard of care” therapeutics is negligible, thereby underlining the need for novel therapeutics, especially personalized approaches. Champions Oncology focuses on personalizing cancer treatment via generating Tumorgraft models from each patient's individual whole tumor. The current study describes the attempt to identify a personalized solution for two patients with metastatic colorectal and duodenal cancers. Using Champions revolutionary Tumorgraft™ technology, personalized ‘trials’ were performed in vivo. Tumor fragments, obtained from the patient's liver metastases, were implanted into immunodeficient mice in a manner that preserves the biological properties of the original tumor and supporting stroma. Once the Tumorgrafts models were established, individual therapeutics and combinations were evaluated to identify treatment regimens likely to be maximally effective in the clinic. Each drug study encompassed 16 different treatment groups, including FDA-approved, as well as investigational agents. Of the different treatment arms in the colorectal model, two demonstrated partial response with tumor growth inhibition values of 152 and 149% for irinotecan/cetuximab/sunitinib and bevacizumab/cetuximab/irinotecan, respectively. While the combination of cetuximab/irinotecan resulted in stable disease in the duodenal model as well, complete responses were observed in all mice treated with eribulin as a single agent. Mutation status analysis of the tumors revealed wild type KRAS. Additional molecular characterization is ongoing to determine other potential signatures of response. The results from the Tumorgraft study were recommended to the patients and their medical oncologists and new lines of treatment were commenced subsequently. The results from these Tumorgraft studies, the molecular profile of the tumors, and correlation with clinical outcome will be presented. Results demonstrate the application of Personalized Tumorgraft models to personalized oncology and their impact on the future of cancer treatment.

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 1329. doi:1538-7445.AM2012-1329
Abstract 1332: Cisd2 haploinsufficiency leads to non-alcoholic fatty liver disease (NAFLD) and accelerates hepatocarcinogenesis in mice
Authors: Kao Cheng-Heng , Shen Zhao-Qing , Chen Yi-Fan , Tsai Ting-Fen
Published: August 2012

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Hepatic steatosis (fatty liver) is a vulnerable factor that could lead to liver damage, inflammation, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). However, despite the high prevalence of NAFLD, the genetic factor determining the disease progression remains poorly understood. CISD2 is a previously uncharacterized novel gene located within the overlapping region of HCC critical region and human longevity region on chromosome 4q. We have recently demonstrated for the first time that Cisd2 is a mitochondrial outer membrane protein which mediates mitochondrial integrity and lifespan in mammals. Surprisingly, we have observed phenotype similar to NAFLD in the liver of Cisd2 heterozygous (+/−) knockout mice. Cisd2 haplo-insufficiency led to abnormal lipid metabolism accompanying with fatty liver, cell death, severe inflammation and fibrosis in the liver. Moreover, there was a low incidence (1/18; 5.6%) of HCC developed at 16-18 months of age in the Cisd2+/− mice. Interestingly, our results revealed a significant increase of the Srebp1c which is the master regulator of lipogenesis; the increase in Srebp1-c seems to further up-regulate the expression of its target gene, fatty acid synthase (Fas), in the Cisd2+/− livers. In addition, we found that liver fibrosis was associated with activation of hepatic stellate cells, as revealed by increased expression of α-ΣMA, in the Cisd2+/− livers. Furthermore, we provide evidence that Cisd2 haplo-insufficiency promoted hepatocarcinogenesis and accelerated HCC development by 4-6 months in the transgenic mice expressing HBV X protein. In summary, our results suggested that Cisd2 is likely to be a haplo-insufficient tumor suppressor gene for HCC. Heterozygous deficiency of Cisd2 led to NAFLD, and accelerated the progression of HBV-associated HCC. Our data suggest that Cisd2 is a molecular target for the development of chemoprevention and therapeutic strategy for NAFLD.

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 1332. doi:1538-7445.AM2012-1332
Abstract 1334: Overexpression of claudin-1 induces Notch and Wnt signaling to regulate colon carcinogenesis
Authors: Dhawan Punita , Pope Jillian , Sharma Ashok , Washington Mary Kay , Singh Amar B.
Published: August 2012

Under physiological conditions, colonic homeostasis is a carefully balanced interplay between stem cells, their progeny, differentiation and cell fate determination. Dysregulation of this harmony signifies susceptibility to neoplastic growth. Colonic epithelium undergoes continuous proliferation, differentiation, and apoptosis along the crypt (crypt bottom to top). Notch signaling is a key regulator of the absorptive/secretory lineage determination. Dysregulation of notch signaling disrupts the normal colonic differentiation and depletes the goblet cell population while immature colonocyte population increases. Importantly, emerging literature suggests that Notch- signaling helps regulate colon cancer growth and progression in association with Wnt signaling. We have previously demonstrated that claudin-1 expression is highly increased in colon cancer and is causally associated with the tumorigenic and metastatic abilities of colon cancer cells. We also reported an inverse relationship between claudin-1 expression and differentiation in colon cancer cells. Here, we show a significant decrease in the goblet cell population (as determined by PAS and Alcian Blue) and Muc-2 expression accompanied with an increase in Carbonic Anhydrase I (CAI) expression, a commonly used marker for colonocytes in Villin-claudin-1 transgenic (Cl-1TG) mice that overexpress claudin-1 in the intestinal epithelium. Further analysis to detect Ki-67 expression suggested increase in colonic proliferation in Cl-1TG mice vs. WT mice. Taken together, these data suggest a role for claudin-1 in the regulation of colonic epithelial differentiation. To further determine the role of claudin-1 overexpression in cancer progression, we crossed Cl-1TG mice with APCmin mice, most widely used mouse model of colon cancer. Notably, APCmin mice develop few colonic tumors (mean=0.8) and have a life span of ∼22.5-23 weeks. Importantly, we noted a ∼4fold increase in the colonic tumor burden in (mean=3.8 tumors) and decrease in life span in APCmin/Cl-1 mice vs. APCmin mice. Also, tumors in APCmin/Cl-1 mice were larger, exhibited high grade of dysplasia and increased nuclear β-catenin (activated Wnt signaling) compared to tumors from APCmin mice. Our further studies using SW480claudin-1 cells {SW480 cells stably overexpressing claudin-1} and SW620siRNA cells {SW620 cells with stable inhibition of claudin-1 expression} demonstrated activation of Notch and Wnt signaling in SW480 cells (APCmutant) overexpressing claudin-1 while inhibited on inhibition of claudin-1. Taken together, our data supported a novel role of claudin-1 in the regulation of Notch and Wnt-signaling and thus colon carcinogenesis.

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 1334. doi:1538-7445.AM2012-1334
Abstract 1335: Involvement of canonical Wnt/β-catenin signaling pathway in pancreatic ductal adenocarcinoma
Authors: Sano Makoto , Driscoll David , Klimstra David S. , DeJesus-Monge Wilfredo , Lewis Brian C.
Published: August 2012

Pancreatic ductal adenocarcinoma (PDAC), a poor prognostic cancer, develops through the progression of premalignant lesions called pancreatic intraductal neoplasms (PanINs). Acinar-to-ductal metaplasia (ADM) is postulated to contribute to PanIN development, and the canonical Wnt/β-catenin pathway has been implicated in this process. To ascertain the impact of postnatal activation of the Wnt/β-catenin pathway in PanIN-PDAC progression, we combined the elasatse-tva-based RCAS-TVA pancreatic cancer model with the established LSL-KrasG12D, Ptf1a-cre model. Delivery of RCAS viruses encoding β-cateninS37A, but not RCAS-GFP, stimulated a shift to higher-grade PanIN lesions in young adult mice. Moreover, mice injected with RCAS-β-cateninS37A had reduced survival relative to RCAS-GFP controls (log-rank test; p <0.05). In addition, overexpression of active β-catenin or its DNA-binding partner TCF4 in PDAC cell lines enhanced cell proliferation, soft-agar colony formation, as well as migration and invasion activity. In contrast, these phenotypes were significantly blocked by the introduction of Icat, an inhibitor of the β-catenin/TCF4 interaction. Together, these data suggest that activation of the Wnt/β-catenin signaling pathway is closely related to pancreatic tumorigenesis and progression of this malignancy.

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 1335. doi:1538-7445.AM2012-1335
Abstract 1336: Concurrent Snail expression and Kras mutation promote pancreatic fibrosis
Authors: Shields Mario A. , Khan Mohammad WK , Grippo Paul J. , Munshi Hidayatullah G.
Published: August 2012

One of the hallmarks of pancreatic ductal adenocarcinoma (PDAC), the 4th leading cause of cancer related death in the US, is a pronounced collagen-rich stromal reaction. We recently published that type I collagen induces expression of Snail, a key regulator of epithelial-mesenchymal transition, to promote invasion and scattering of PDAC cells (Shields MA, et al. JBC 2011). To further understand the role of Snail in PDAC progression we generated transgenic mice expressing Snail in the pancreas. While there was robust Snail expression in the mouse pancreas, no phenotypic changes were observed. Since inflammation can promote Snail-mediated invasion and metastasis, we treated the Snail-expressing mice with cerulein to induce chronic pancreatitis. Although there was significant inflammation associated with vacuolization, no difference in the pancreatitis response was observed between control and Snail-expressing mice. Since Kras mutation has been shown to be necessary for tumor development in mouse models of pancreatic cancer, we generated mice expressing both mutant KrasG12D and Snail (Kras+/Snail+). Compared to control mice (Kras+/Snail-), Kras+/Snail+ mice developed significantly more acinar to ductal metaplasia, cystic papillary lesions that were associated with increased fibrosis, increased Smad2 and Stat3 phosphorylation. Experiments are underway characterizing the mechanism by which Snail promotes pancreatic fibrosis in Kras-expressing mice.

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 1336. doi:1538-7445.AM2012-1336
Abstract 1342: Nuclear Apc suppresses colitis-associated tumorigenesis in mice
Authors: Zeineldin Maged , Neufeld Kristi L.
Published: August 2012

Because mutation of tumor suppressor gene APC is the initiating step in most colorectal cancers (CRC), understanding the full spectrum of APC functions will illuminate better diagnostic, preventive and therapeutic strategies for the disease. Although APC shuttles between the cytoplasm and nucleus, testing proposed roles for nuclear APC in the context of a whole organism was only recently made possible using a mouse model compromised for nuclear Apc which we generated by introducing germline mutations that inactivate the Apc nuclear localization signals (ApcmNLS). Our previous analysis of ApcmNLS mice revealed a role for nuclear Apc in regulation of Wnt signal transduction and intestinal cell proliferation as well as in tumor suppression. In humans, chronic colitis significantly increases CRC risk and APC mutations occur late in this cancer progression. In the current study, we show increased expression of inflammatory mediators cyclo-oxygenase-2 (Cox-2) and macrophage-inflammatory-protein-2 (MIP-2) in colon epithelial cells from ApcmNLS/mNLS mice, suggesting a role for nuclear Apc in suppressing colitis-mediated colon cancer. To test this hypothesis, we initiated colon tumors with a single injection of the mutagen, azoxymethane (AOM) and promoted the tumors with repeated oral administration of dextran sodium sulfate (DSS) to induce colonic inflammation. When treated with AOM-DSS, ApcmNLS/mNLS mice developed more colonic tumors than treated wildtype mice. Tumors from treated ApcmNLS/mNLS and wildtype mice had the same spectrum of β-catenin mutations, proliferation rates and histopathological features, consistent with the ApcmNLS allele enhancing colitis-associated tumor initiation rather than progression. ApcmNLS/mNLS mice had increased weight loss and colonic lymphoid follicles implicating nuclear Apc in suppression of AOM-DSS-induced colitis. These findings reveal novel functions for nuclear Apc and also indicate a critical protective role for Apc early in inflammation-induced colon tumorigenesis.

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 1342. doi:1538-7445.AM2012-1342
Abstract 1344: ZAP-70 enhances migration of malignant B lymphocytes toward lymphoid organs in a Burkitt lymphoma xenograft model
Authors: Calpe Eva , Purroy Noelia , Abrisqueta Pau , Carpio Cecilia , Palacio Carles , Gallur Laura , Castellvi Josep , Crespo Marta , Bosch Francesc
Published: August 2012

Chronic Lymphocytic Leukemia (CLL) is a lymphoproliferative disease characterized by the accumulation and proliferation of mature B-lymphocytes in the blood, bone marrow and secondary lymphoid organs. CLL patients with adverse outcome prognosis can be identified by the presence of a high ZAP-70 expression. ZAP-70, a protein tyrosine kinase that plays a crucial role in cellular activation in T and NK cells, has been related to aggressive features of the CLL cells, such as higher migrative capacity in vitro. In order to analyze the consequences of ZAP-70 ectopic expression in an in vivo model, we stably transfected a Burkitt cell line (Raji) with a vector expressing a ZAP-70-GFP fusion protein. Raji transfectants showed constitutively active ZAP-70 protein. Subsequently, thirty-four 8-week old SCID mice were inoculated intravenously with 5 x106 cells from each cell line (control Raji-GFP, 12 mice; Raji-ZAP-70-GFP, 9 mice). Mice were euthanized when hind legs paralysis, dyspnea, or tumor growth was observed. Organs were obtained to quantify the percentage of GFP-positive cells present in each organ by flow cytometry. Median survival of mice injected with the ZAP-70 cell line did not differ from that observed in the control mice (16 days, p=0.658). Percentage of GFP positive cells was analyzed by flow cytometry in different tissue compartments (Table 1). We observed a significantly higher percentage of infiltrating GFP-positive cells in the bone marrow from mice injected with ZAP-70 expressing cell line (58.8%±6.08 vs 4.2%±1.4, p<0.001), whereas in the rest of organs the infiltration was comparable (Table 1). Raji-ZAP-70-GFP has a differential expression of CCR7 and CD49d among others (Calpe et al, Blood 2011). In conclusion, malignant B-lymphocytes with ectopic expression of activated ZAP-70 protein showed enhanced ability to migrate toward and infiltrate the bone marrow, where soluble factors are produced to mediate homing, survival, and proliferation of tumor cells.

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 1344. doi:1538-7445.AM2012-1344
Abstract 1345: The use of optical imaging in a clinically relevant mouse intrafemoral model of leukaemia
Authors: Batey Michael A. , Brown Matthew , Booth Catherine
Published: August 2012

One of the challenges facing preclinical development in non solid tumours, such as leukaemia, is the development and validation of clinically relevant models, both to better understand the biology of disease, and to provide reliable efficacy testing for novel agents. In conventional animal models of leukaemia, cells are implanted using intravenous injection, leading to inconsistent engraftment as cells are not introduced directly to their biological niche. Disease burden is measured using either terminal endpoints, such as hind limb paralysis, or by fluorescence activated cell sorting on bone marrow or peripheral blood samples. Neither of these strategies make it practical to identify animals in the early stages of leukemic disease development, limiting investigators’ ability to examine novel therapies in these models. The use of preclinical imaging strategies, such as in vivo optical imaging, allows disease progression to be followed at orthotopic sites and, in the case of non solid tumours, to monitor systemic disease burden longitudinally in an individual animal over time. Here we describe the use of an intrafemoral (i.f.) transplantation method, in which cells are implanted directly into the biological niche of interest, correlating with the environment in which disease develops in patients. Luciferase-labelled human leukaemia cell lines were injected into the bone marrow cavity of the femur of severely immunocompromised NOG (NOD/Shi-scid/IL-2Rynull) mice via the knee joint. Animals were followed over a period of several weeks from initial transplantation, and disease burden monitored and quantified using bioluminescent detection. This model consistently gives rise to disease disseminating gradually from the site of initial transplantation into systemic leukaemia. The ability to quickly identify engraftment and the predictable development of disease allows for therapeutic intervention at an early stage and extends the window available for therapy. The model provides a clinically relevant environment for the preclinical assessment of novel therapeutics for non solid tumours.

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 1345. doi:1538-7445.AM2012-1345
Abstract 1347: A human-mouse xenograft model to study the role of TSLP in CRLF2d B-ALL
Authors: Payne Kimberly J. , Su Rui-Jun , Francis Olivia L. , Martinez Shannalee R. , Bennett Terrence , Arogyaswamy Keshav , Morris Christopher L. , Dovat Sinisa
Published: August 2012

B-cell precursor ALL where genetic defects lead to overexpression of CRLF2 (CRLF2d B-ALL) are high-risk with poor prognosis. CRLFd B-ALL occurs 5 times more frequently among children of Hispanic/Latino ethnicity and is a major contributor to the health disparity in survival of Hispanic children with ALL. CRLF2, together with the IL-7Rα, forms a receptor complex that is activated by the cytokine, TSLP. The JAK-STAT5 pathway is phosphorylated downstream of receptor activation. The activating JAK mutations found in some CRLF2 B-ALL have led to speculation that TSLP stimulation is not a factor in CRLF B-ALL. In preliminary studies to address this question we evaluated the effect of TSLP on two CRLF2d B-ALL cell lines with JAK defects and which have been reported to exhibit constitutive JAK-STAT5 activation. Our data show that TSLP increases STAT5 phosphorylation in both of these cell lines and in primary B-ALL cells that overexpress CRLF2. Our next step was to evaluate the role of TSLP-CRLF2 interaction in vivo in the human-mouse xenograft model. However, mouse TSLP is different from most other cytokines produced in the xenograft in that it is species-specific and does not activate the human TSLP receptor complex that contains CRLF2. Thus, traditional xenograft models do not provide the TSLP-CRLF2 interactions that we believe to be a major factor in CRLF2 B-ALL. To overcome this obstacle we have engineered immune deficient NOD/SCID IL-2Rγ null (NSG) mice to express human TSLP (hTSLP+ mice) as well as control mice that lack the TSLP cytokine (hTSLP- mice). ELISA assays show plasma hTSLP levels in the hTSLP+ mice that approximate the normal range in human plasma. We have used this hTSLP+/− system to expand a sample of primary pre-B ALL cells from a patient that includes clones of CRLF2-HI and CRLF2- B-ALL cells. Preliminary data indicate that the pre-B ALL cells expanded in hTSLP+ mice show higher expression levels of the TSLPR components (CRLF2 and IL-7Rα) than cells expanded in the hTSLP- mice. This data provide evidence that the TSLP produced in this model is active and that it impacts primary pre-B ALL cells. The hTSLP+ mice that we produce will allow for the first time the study of normal and malignant B lymphopoiesis in a model that provides the complex bone marrow architecture of the xenograft while providing the full range of cytokines that are known to act on early B lineage cells (IL-7, FL and TSLP). This model will be particularly important for identifying therapies that can effectively target CRLF2-d B-ALL and reduce cancer health disparities in Hispanic childhood B-ALL.

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 1347. doi:1538-7445.AM2012-1347
Abstract 1349: Xenograft models of human acute myeloid leukemia (AML) with biomarker strategies are valuable in development of new drugs targeting AML
Authors: Zhang Lan , Chen Taiping , Shi Qian , Zhang Juan
Published: August 2012

Acute myeloid leukemia (AML) is a malignant disease caused by disorder of progenitor cells in myeloid hematopoiesis. The rapid progress and high fatality make it difficult to cure the patients suffering from AML. Choice of treatment is limited, consisting primarily of chemotherapy and hematopoietic stem cell transplantation. Pharmaceutical companies are focused on designing new drugs that may be efficacious in treating the disease and prolong the survival of the patients. However, the lack of AML model and specific biomarkers hinder the progress of research on this cancer type. Here we successfully validated subcutaneous and systemic models derived from a number of AML cell lines, such as MV4-11, HL-60, Molm-16, and ML-2, in NOD/SCID mice to evaluate the antitumor activities of new compounds. Biomarkers, such as CD45, CD38 and CD15 in PBMC, spleen and bone marrow from the systemic models, are used in detecting and monitoring the disease progress. These biomarkers correlated with tumor take rate, disease progression and response to standard of care treatments. In conclusion, AML xenograft models with biomarker strategies provide valuable platforms for the development of new compounds targeting this deadly disease.

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 1349. doi:1538-7445.AM2012-1349
Abstract 135: Integrated analysis of cell signaling pathway-associated miRNAs using protein expression array data in NCI-60 cells
Authors: Kim Sang-Bae , Park Yun-Yong , Sohn Bo-Hwa , Jeong Woojin , Lee Sung Sook , Kim Ji Hoon , Davies Micheal A. , Mills Gordon B.
Published: August 2012

MicroRNAs (miRNAs) are single-stranded, non-coding RNA molecules and on average only 22 nucleotides long that regulate gene expression at the post-transcriptional level. The current approaches with miRNA-mRNA association were not enough to verify real functional targets at protein level, which could affect on biological signaling pathway. In this study, we developed a correlation based approach (sequence-independence) to predict potential miRNA targets with genomic and proteomic data including the expression of phosphorylated proteins in NCI-60 cells. To do this we calculated the number of correlated probe-pairs between miRNA(439)-mRNA(22k) and protein(222)-mRNA probe pairs. Then, two significant output pair sets were combined by mRNA probes and then counted the number of common probes. With these count numbers, finally we generated Association score matrix between miRNA and protein probes. Using those score matrix, we evaluated the highly associated miRNAs with 36 biological pathways, which play critical roles in cell cycle, proliferation and metastasis. Among these associations, we found that miR-500 cluster is highly associated with ERK/MAPK signaling pathway through activating MEK1/2 phosphorylation in Melanoma and breast cancer cells. In conclusion, we developed a novel expression profile based approach to systematically predict potential miRNA functional targets which play critical roles in cell signaling pathways from the NCI-60 genomic and proteomic data at whole genomic scale.

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 135. doi:1538-7445.AM2012-135
Abstract 1353: Inactivation of ribosomal protein L22 promotes transformation by induction of Lin28B
Authors: Rao Shuyun , Lee Sangyun , Guitierrez Alejandro , Perrigoue Jacqueline Jacqueline , Thapa Roshan , Tu Zhigang , Jeffers John , Rhodes Michele , Hunger Stephen , Downing James , Zhang Rugang , Balachandran Siddharth , Zambetti Gerard , Testa Joseph , Look A. Thomas , Wiest David
Published: August 2012

The molecular basis by which mutations in some ribosomal proteins (RP) predispose to development of hematologic malignancies remains unclear. We show here that germline inactivation of the ribosomal protein L22 (Rpl22), which selectively blocks T cell development, also predisposes T lineage progenitors to transformation. Indeed, RPL22 was found to be inactivated in ∼9% of human T-acute lymphoblastic leukemias (T-ALL). Moreover, mono-allelic loss of Rpl22 accelerates development of thymic lymphoma in a mouse model of T cell malignancy and in acute transformation assays in vitro. Furthermore, we show that Rpl22 inactivation enhances transformation potential through induction of Lin28B. These findings represent the first mechanistic insight into how an RP mutation promotes transformation.Our finding that Rpl22 inactivation promotes transformation by inducing expression of Lin28B provides insight into the mechanistic basis by which mutations in Rpl22, and perhaps other RP genes, increase cancer risk. In addition, because we have determined that Lin28B induction is dependent upon NF-kB activity, our findings may provide new opportunities for therapeutic intervention both in aggressive forms of T-ALL, where we have found Rpl22 to be inactivated, and perhaps in other diseases caused by mutations in RP genes.

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 1353. doi:1538-7445.AM2012-1353
Abstract 1356: Vascular endothelial growth inhibitor - potential role in targeted therapy in kidney neoplasma via angiogenic inhibition
Authors: Cai Jie , Zhang Ning , Zhao Xueqing , Su Dan , Song Xiaoming , Wu Liyang , Wang Wei , Sun Yanmei , Shi Qian , Chen Taiping , Yang Yong
Published: August 2012

Vascular endothelial growth inhibitor (VEGI, also known as TNFSF15) is an anti-angiogenic cytokine found to be associated with tumour-related vasculature in certain maligancies. Three isoforms, VEGI 251, VEGI192, and VEGI174, have been identified, all sharing a common extracellular domain of 151 C-terminal amino acid sequence critical for biological activity of all three isoforms. Previous studies showed tumor inhibitory effect of truncated recombinant VEGI proteins in breast and colorectal cancer xenograft models, however, the antitumor activity of the full length VEGI molecules have not been well characterized in other malignancies, including kidney neoplasm. The objective of the present study was set to evaluate biological impact of forced expression of full length VEGI-174 in a renal cell carcinoma (RCC) cell line, 786-O, and in 786-O derived xenograft models. We found that Increased VEGI-174 expression in 786-O cells did not affect cell growth and apoptosis in vitro, but did reduce cell adhesion and the ability of endothelial cells to form capillary-like structures in co-culture. Subcutaneous xenograft models were successfully established using the 786-O RCC cells with or without forced expression of VEGI-174. Significantly reduced tumor volume, accompanied by reduced tumor microvessel density and decreased Ki67 and VEGFR2 expression, was observed in animals injected with VEGI-174 transfected 786-O cells compared to those in the control groups. Our results demonstrated that increased expression of full length VEGI-174 in RCC 786-O cells resulted in significant reduction in tumor volume most likely via angiogenic inhibition rather than on tumor growth per se. Despite the lack of antitumor effect of full length VEGI174 in some xenograft tumor models in other studies, our results suggest that antitumor effect of the full length VEGI-174 may be cancer type specific, and VEGI-174 may still be a valuable candidate toward angiogenesis based cancer therapy.

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 1356. doi:1538-7445.AM2012-1356
Abstract 1357: Creation and establishment of xenograft model for uterine leiomyoma in immunodeficient mice
Authors: Cho Chi-Heum , Shin So-Jin , Kwon Sang-Hoon , Cha Soon-Do
Published: August 2012

Objective: Uterine leiomyomas are the most prevalent benign tumors in women of reproductive age and the leading indication for hysterectomy in premenopausal women. The underlying causes of uterine leiomyomas are poorly understood, as a result, in part, of the absence of a good model system with which to study these tumors. To overcome this problem, this study was undertaken to develop a murine model for human leiomyoma. Study design: Human leiomyoma tissues were cut into small pieces and some of those were cultured. Tissue pieces and cultured cells were inserted subcutaneously in the flank of each severe immunodeficiency (NOD/SCID gamma, NSG) mice (n=6). Estrogen supplement was needed to maintain serum estrogen level 3 days before the tissue or cultured cells transplantation. Xenograft tissues or cells were harvested after 6wks and analyzed. Results: Six uterine leiomyoma xenografts were successfully established with the tumor tissue derived from six patients. The xenografted human uterine leiomyoma tissues retained their gross appearance with small vessels around the implant tissues and did not change in size up to 6wks after implantation. H&E staining showed that xenografts retained major histologic features of the original leiomyoma. The immunohistochemical staining of SMA(smooth muscle actin) revealed strong cytoplasmic and membranous positivity of spindle tumor cells of xenografts.Conclusions: In summary, transplantation of surgical specimens from uterine leiomyoma patients into NSG mice results in an attractive model for the study of the uterine leiomyoma and may also be useful for analysis or new experimental therapeutic approaches for the treatment of this disease.

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 1357. doi:1538-7445.AM2012-1357