bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3417: An in vivo functional screen to identify metastasis suppressor genes
Authors: Murugaesu Nirupa , Iravani Marjan , Johnson Damian , Antonopoulos Aristotelis , Sims David , Fenwick Kerry , Mitsopoulos Costas , Gao Qiong , Orr Nick , Zvelebil Marketa , Haslam Stuart , Dell Anne , Lord Christopher , Ashworth Alan , Isacke Clare
Published: August 2012

Background When breast carcinomas remain confined to breast tissue, cure rates exceed 90% (http://seer.cancer.gov/csr/1975_2006/). However, if the cancer disseminates through the body, long-term survival decreases depending upon the extent of, and the sites of, colonisation Genes that control the different stages of the metastatic process need to be identified to better delineate the process, and to aid in the development of metastatic biomarkers and provide potential targets for the treatment of metastatic disease. Genetic screens, such as those that exploit RNA interference (RNAi), provide an unbiased approach to the identification of genes associated with a phenotype of interest. Although cell-based screens have been highly informative in identifying genes involved in tumour cell survival, migration and invasion, these in vitro approaches are largely unsuitable for interrogating the later stages of the metastatic process, in particular the processes of cell dissemination, tumour cell extravasation from the circulation and colonisation of secondary sites. Method Using the 4T1 mouse model an in vivo functional metastasis screen that integrates RNAi technology and massively parallel sequencing was implemented to rapidly discover and validate metastasis genes. Results Using this approach, 12 ‘hits’ that suppress tumour cell colonisation of the lungs were identified. 3 of the top 5 hits have been validated as novel metastasis suppressor genes in both mouse and human cell lines and further studies have been undertaken to elucidate the mechanism of action of the top hit. Critically, these findings are clinically relevant in primary breast cancers where there is a significant correlation between elevated expression levels of these suppressor genes and reduced frequency of metastatic events. Conclusion This study demonstrates the value of adopting an unbiased methodology to discover novel metastatic genes and establishes, for the first time, that an in vivo metastasis screen can be combined with next generation sequencing to identify novel components of the metastatic process.

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 3417. doi:1538-7445.AM2012-3417
Abstract 342: Silencing of IGF1R induces mesenchymal-to-epithelial transition and inhibits the metastatic properties of triple negative breast cancer cells
Authors: Taliaferro-Smith LaTonia D. , Oberlick Elaine M. , Liu Tongriu , Adams Amy , Eggers Carrie , Kline Erik , Nagaraju Ganji P. , Cohen Cynthia , Marcus Adam , O'Regan Ruth
Published: August 2012

Next to skin cancer, breast cancer is the second most common cancer diagnosed among American women and affects nearly 1.3 million women worldwide each year. Aggressive, metastatic disease is directly responsible for the majority of breast cancer-related deaths. Breast tumors lacking expression of three receptors, estrogen receptor (ER), progesterone receptor (PR), and HER2, are commonly referred to as triple negative breast cancers (TNBCs) and make up 15-20% of all diagnosed breast cancers cases. Disparities exist in terms of survival following diagnosis of TNBC, and a devastating reality is that this diagnosis is highly correlated with incurable, metastatic disease. Despite tremendous advantages in treatments for hormone-sensitive breast tumors, a significant number of women with TNBC experience disease progression due to the unavailability of targeted therapies. Insulin-like growth factor-1 receptor (IGF1R) plays a role in breast cancer proliferation, adhesion, invasion, and migration. Overexpression of IGF1R has been noted in 50% of primary breast tumors and in nearly 65% of TNBCs. Consequently, high IGF1R expression in breast cancers correlates well with, high tumor grade, shorter disease-free survival, and poor prognosis. We report the in vitro effects of IGF1R inhibition on the metastatic properties of mesenchymal TNBC cells lines using two methods: (1) shRNA lentiviral system and (2) picropodophyllin (PPP), an IGF1R tyrosine kinase inhibitor. Stably transfected mesenchymal TNBC cells showed down-regulation of IGF1R protein levels, which resulted in mesenchymal-epithelial-transition (MET), as confirmed by up-regulation of epithelial marker, E-cadherin, and down-regulation of mesenchymal marker, vimentin. Importantly, this MET was accompanied by reduced colony formation, cell motility, and invasion. Cell survival assays and fluorescence-activated cell sorting (FACS) analysis revealed that PPP also effectively decreased cell viability and induced cell death, respectively, in TNBC cells. Furthermore, PPP dramatically inhibited cell invasion and migration. Our findings indicate that inhibitors of IGF1R exhibit promising anti-cancer activity in TNBC cells of mesenchymal origin by triggering MET, inducing cell death, and reducing invasive and metastatic properties. Given the very poor outcomes for patients with metastatic TNBCs, we believe the use of IGF1R inhibitors warrant further investigation as prospective anti-cancer options for treating a subset of mesenchymal TN breast carcinomas.

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 342. doi:1538-7445.AM2012-342
Abstract 3422: N-α-acetyltransferase 10 protein suppresses cancer cell metastasis by binding PIX proteins and inhibiting Cdc42/Rac1 activity
Authors: Hua Kuo-Tai , Tan Ching-Ting , Chen Chi-Kuan , Chen Min-Wei , Hsiao Michael , Kuo Min-Liang
Published: August 2012

80%-90% of eukaryotic proteins are N-α-terminally acetylated. They are mediated by specific N-α-acetyltransferases. However, the biological importance of these N-α-acetyltransferases remains largely unknown. Recently, these N-α-acetyltransferases have been recognized as important characters in many biological processes, including embryonic development, neuron disease and cancer. N-α-acetyltransferase A (Nat A) was first characterized in yeast, it composed of Naa10p, also known as hARD1 (human Arrest defective 1), and Naa15p, also known as NATH (N-acetyl transferase human), are responsible for the N-α-acetylation of majority proteins in mammalian cells. Naa10p is known to be involved in cell cycle control and apoptosis. However, the role of Naa10p in human cancers is elusive. In this study, we found that elevated Naa10p levels are associated with less metastasis to lymph nodes and better prognosis of cancer patients. Naa10p significantly suppressed migration, tumor growth, and metastasis independent of its enzymatic activity. Instead, Naa10p binds to the GIT-binding domain of PIX, thereby preventing the formation of the GIT-PIX-Paxillin complex, resulting in reduced intrinsic Cdc42/Rac1 activity and decreased cell migration. Forced expression of PIX in Naa10-transfected tumor cells restored the migration and metastasis ability. We suggest that Naa10p functions as a tumor metastasis suppressor by disrupting the migratory complex, PIX-GIT- Paxillin, in cancer cells. Our study not only highlights the potential of Naa10p as a therapeutic target for tumor metastasis, but also identifies Naa10p as a regulatory component of the migration complex PIX-GIT-Paxillin.

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 3422. doi:1538-7445.AM2012-3422
Abstract 3441: Silencing glucosylceramide synthase using MBO-asGCS eliminates tumor metastasis
Authors: Bhinge Kaustubh N. , Gupta Vineet , Liu Yong Yu
Published: August 2012

Disseminated metastasis is often observed in cancer patients fail in chemotherapy. Tumor metastasis is known to rely on the interaction of cancer cells and the extracellular matrix components but the molecular mechanism by which drug resistance promotes tumor metastasis is still not clear. Glucosylceramide synthase (GCS) that is a limiting enzyme for ceramide glycosylation and regulates glycosphingolipid (GSL) synthesis can cause drug resistance. Hence we report that GCS is a determinant of metastatic properties of drug-resistant cancer cells, and silencing GCS eliminates tumor metastasis. Our recent study found that the metastatic potency of drug-resistant cancer cells depended on the overexpression of GCS. Compared with drug-sensitive MCF-7 cells, the wound healing, matrigel attachment and MMP-9 activity significantly was 1.5 fold faster, 3 fold more and 2 folds higher respectively in the drug resistant MCF-7/Dox that also had 39-fold higher GCS protein level and 2-fold higher GCS enzyme activity. Introduction of GCS gene enhanced the metastatic potency of MCF-7 cells, because its matrigel attachment and invasion potential significantly increased by 2-fold and 1.5-fold after transfection. In contrast, silencing GCS by using mixed-backbone oligonucleotide against GCS (MBO-asGCS, 100 nM) substantially diminished the metastatic potency of MCF-7/Dox cells, as the wound healing, matrigel attachment and invasion reduced by 2-fold, 1.5-fold and 3-fold respectively. MBO-asGCS treatments eliminated lung metastasis of MCF-7/Dox tumors. Further mechanistic studies disclosed that silencing GCS by MBO-asGCS decreased its expression and enzyme activity and also decreased the levels of globo-series glycosphingolipids (GSLs) in GSL-enriched microdomain located on the plasma membrane. Sequentially, silencing GCS decreased the expression levels of uPA, MMP-9, VEGF and FGF-2 that actively mediated the migration and invasion of cancer cells. This study thus indicates that GCS is determinant for the metastatic potency of drug-resistant cancer cells and silencing GCS by using MBO-asGCS is an effective approach to target the metastasis of tumor with drug resistance.

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 3441. doi:1538-7445.AM2012-3441
Abstract 345: Circulating tumor cells from perfusable tumor nodules grown on decellularized rat lung scaffold has mesenchymal characteristics
Authors: Mishra Dhruva K. , Baird Brandi N. , Ott Harald C. , Gibbons Don L. , Kurie Jonathan M. , Kim Min P.
Published: August 2012

Circulating tumor cells are thought to be responsible for metastasis. These cells leave the primary site of cancer and enter the circulation after undergoing epithelial to mesenchymal transition. The tumor cells lose the epithelial features, such as expression of E-cadherin, and acquire mesenchymal characteristics, such as expression of Twist1, Zeb and N-cadherin. In this study, we developed a novel ex vivo model that utilizes a decellularized rat lung scaffold to grow tumor nodules and study circulating tumor cells. We hypothesized that circulating tumor cells in our ex vivo model will have mesenchymal characteristics. We created the decellularized rat lung scaffold using SDS and Triton-X. We then placed 344SQ or 393P mice lung cancer cell lines in the decellularized rat lung scaffold and perfused them in a customized bioreactor. We measured tumor growth on the scaffold and the number of circulating tumor cells for 14 days. We then analyzed the functional characteristics of the circulating tumor cells using the Boyden chamber and determined gene expression of E-cadherin, N-cadherin, Zeb1 and Twist. Both the 344SQ and 393P lung cancer cell lines formed tumor nodules that gradually increased in size with an increase in the number of circulating tumor cells over the 14-day period in our model. The circulating tumor cells had greater ability to migrate than the monolayer cell cultures in the Boyden chamber assay, with 100% of the circulating tumor cells migrating in contrast to 69% and 71% of the monolayer cell cultures of 344SQ and 393P, respectively. The circulating 393P tumor cells had a significant increase in Twist (58-fold), Zeb (20-fold) and N-cadherin (14-fold) and decrease in E-cadherin compared to the 393P cells from the monolayer cell culture. This difference was even more dramatic for the circulating 344SQ tumor cells with an increase in Twist (>6000-fold), Zeb (14-fold) and N-cadherin (88-fold) compared to the 344SQ cells from the monolayer. There was small 4-fold increase in E-cadherin expression in the circulating 344SQ tumor cells compare to the 344SQ cells from the monolayer. The circulating tumor cells in our model have both phenotypic and genotypic characteristics of mesenchymal cells. The cancer cells that are more mesenchymal at the baseline have a greater difference in these characteristics. The circulating tumor cells in our model may be the sub-population of cells responsible for metastasis.

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 345. doi:1538-7445.AM2012-345
Abstract 3458: Wnt activation is implicated in glioblastoma radioresistance
Authors: Kim Yonghyun , Kim Kang Ho , Lee Hyewon , Yang Heekyoung , Kim Donggeon , Kang Wonyoung , Jin Juyoun , Joo Kyeung Min , Lee Jeongwu , Nam Do-Hyun
Published: August 2012

Glioblastoma (GBM) patients have dismal median survival even with the most rigorous treatments currently available. Radiotherapy is the most effective non-surgical therapy for GBM patients; however, patients succumb due to tumor recurrence within a year. To develop a curative therapeutic approach, we need to better understand the underlying molecular mechanism of radiation resistance in GBM. Towards this goal, we developed an in vivo orthotopic GBM model system that mimics the radiation response of human GBM, using both established-GBM cell line and patient-derived freshly dissociated GBM specimen. In-vivo ionizing radiation (IR) treatment prolonged the survival of mice with intracranical tumor derived from U373MG, but failed to prevent tumor recurrence. U373MG and GBM578 cells isolated after in-vivo IR (U373-IR and 578-IR) were more clonogenic and enriched with stem cell-like characteristics, compared with mock-treated control tumor cells. Transcriptomic analyses and quantitative real-time reverse-transcription PCR analyses using these matched GBM cells before and after radiation treatment revealed that Wnt pathways were preferentially activated in post-IR GBM cells. U373-IR cells and 578-IR were enriched with cells positive for both active b-catenin (ABC) and Sox2 population, and this subpopulation was further increased after additional in-vitro radiation treatment, suggesting that radiation resistance of GBM is mediated due, in part, to the activation of stem cell-associated pathways including Wnt. Finally, pharmacological and siRNA inhibition of Wnt pathway significantly decreased the survival and clonogenicity of GBM cells and reduced their ABCþ/Sox2þ population. Together, these data suggest that Wnt activation is a molecular mechanism to confer GBM radioresistance and an important therapeutic target.

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 3458. doi:1538-7445.AM2012-3458
Abstract 3459: Radioresistence mechanism of prostate cancer stem cells
Authors: jung Kang Mun , Kim Young Seok , Cho Yong Mee
Published: August 2012

BACKGOUND. Radiotherapy induces tumor cell killing mainly by DNA damage and is widely used as one of the main therapeutic modalities for prostate cancer. However, a significant proportion of prostate cancer patients experiences tumor recurrence after radiotherapy and eventually dies of the disease. We previously observed that ionizing radiation (IR) initially damaged prostate cancer stem cells (pCSCs) but levels of CSCs were increased in the recurrent tumors of prostate cancer cell lines and human prostate cancer tissues. METHODS. To define the radioresistance mechanism of pCSCs, we examined expressions of DNA-repair proteins [Ku70, Ku80 and Ataxia telangiectasia and Rad3-related protein kinase (ATR)], cell cycle distribution, and levels of intracellular reactive oxygen species (ROS) in prostaspheres, which is one of pCSC models, and compared to those of total population of a prostate cancer cell line LNCaP. Expressions of DNA-repair proteins were also examined in human prostate cancer tissues harvested before and after radiotherapy. RESTULTS. In non-irradiated cells, the expressions of Ku70 and Ku80 were higher in prostaspheres compared to those of total population. ATR expression was inconspicuous in both cells. After IR with 10 Gy, the expressions of Ku 70, Ku 80, and ATR proteins were increased in both cells with higher levels in prostaspheres than those of total population. Although there was a tendency that prostaspheres belonged to more in G1 phase and less in S phase of cell cycle, it was not statistically significant. Apoptotic cell population and expressions of total and cleaved forms of caspase 3 were not different between prostaspheres and total population. Prostaspheres contained one group of cells that had low levels of ROS. In recurrent human prostate cancer tissue after radiotherapy, expressions of Ku70 and Ku80 were tended to increase. CONCLUSIONS. These results demonstrate that pCSCs contain more DNA-repair proteins and less amount of RCO compared to total population. They suggest that pCSCs have better DNA-repair mechanism and less vulnerability to oxidative damage compared to differentiated 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 3459. doi:1538-7445.AM2012-3459
Abstract 3482: Validation of novel therapeutic targets for T-cell non-Hodgkin lymphoma
Authors: Ito Daisuke , O'Brien Timothy D. , Modiano Jaime F.
Published: August 2012

T-cell malignancies account for 10-15% of all human non-Hodgkin lymphomas (NHL). T-cell lymphomas are incurable, and the development of effective treatment strategies has been hindered by the relatively infrequency of these conditions. T-cell lymphomas occur spontaneously in dogs; they are morphologically similar to human T-cell lymphomas, resemble their biological behavior, and are relatively common (∼35% of all NHL), providing opportunities to improve our understanding of the pathogenesis of these tumors as well as to develop more effective therapies. Tumor-initiating cells (TICs) influence tumor progression and response to therapy in many cancers, so eliminating these cells may be necessary to achieve durable remissions. However, the existence of TICs and their potential significance have not been conclusively established in T-cell NHL. The objective of this study was to evaluate the existence of progenitor-like lymphoma cells (PLCs) in naturally occurring canine T-cell NHL. We identified a reproducible population of tumor-related PLCs in spontaneous T-cell malignancies. The cells expressed the hematopoietic progenitor antigen CD34 and tumor-specific T-cell receptor gene rearrangements. Somewhat unexpectedly, these cells also express B-cell surface proteins (CD20 and CD22), but not the major T-cell surface antigens (CD3 and CD5) that were expressed by the bulk of the tumor cells (BTCs). We have adapted a xenotransplantation assay for primary canine T-cell NHL using NOD/SCID/IL-2Rgammanull mice and genetically modifying the tumor cells to express luciferase as a means monitor tumor growth and distribution by in vivo imaging. This model allows us to expand and serially transplant primary canine T-cell NHL for more detailed studies, including limiting dilution assays and therapeutic targeting using anti-B-cell reagents. In summary, we propose a novel concept in which a small population of tumor cells with “B-cell progenitor” phenotypes may paradoxically contribute to the pathogenesis of T-cell lymphoma, potentially representing a novel therapeutic target. We already use dogs with naturally occurring disease in the pathway for therapy development, allowing us to expand these studies into clinical trials that can then be rapidly translated to benefit human patients (for example, by using approved agents such as anti-CD20 antibodies or CD22-targeted immunotoxins).

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 3482. doi:1538-7445.AM2012-3482
Abstract 3496: Self-renewal as a therapeutic target in human colorectal cancer
Authors: Kreso Antonija , van Galen Peter , Davis Thomas , Szentgyorgyi Eva , O'Brien Catherine , Dick John E.
Published: August 2012

Tumor recurrence following treatment remains a major clinical challenge. Evidence from xenograft models and human trials indicates selective enrichment of cancer-initiating cells (C-ICs) in tumors that survive therapy. Together with recent reports showing that C-IC gene signatures influence patient survival, these studies predict that targeting self-renewal, the key stemness property unique to C-ICs, may represent a new paradigm in cancer therapy. Here we demonstrate that tumor formation, and more specifically human colorectal C-IC function are dependent on the canonical self-renewal regulator BMI-1. Down-regulation of BMI-1 inhibits the ability of colorectal C-ICs to self-renew resulting in the abrogation of their tumorigenic potential. Treatment of primary colorectal cancer xenografts with small molecule BMI-1 inhibitors resulted in colorectal C-IC loss with long-term and irreversible impairment of tumor growth. Targeting the Bmi-1 related self-renewal machinery provides the basis for a new therapeutic approach in the treatment of colorectal cancer.

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 3496. doi:1538-7445.AM2012-3496
Abstract 35: Breast cancer cell interactions
Authors: Georgoulia Nefeli E. , Mitchison Timothy J.
Published: August 2012

In this study, a cell culture approach is employed to identify patterns of pair-wise interaction between cancer cells over a panel of 20 established epithelial breast cancer cell lines. It is our hypothesis that different clones within a tumor, as well as different cell lines in cultured conditions, interact in one of two ways: a) by competitive growth or, b) by synergistic growth. We investigate this by culturing cell lines in serum-free conditioned medium (CM), i.e. medium which has already been used on other cell lines. Cell population growth is monitored by incubating cultures with 5-Ethyl-2′-deoxyuridine (EdU). Cell apoptosis is obtained by labeling fixed cultures with a cleaved Poly ADP Ribose Polymerase (c-PARP) monoclonal antibody. Results yield two 20x20 matrices of cell to CM interaction, and confirm that cancer cells interact through secreted substances in the medium. In an effort to trace these phenomenological interactions back to specific biochemical pathways, the interaction matrices are correlated to gene expression data available for these cell lines. Furthermore, the experiment reveals two cell lines, HCC38 and BT20, whose media produce a strong apoptotic and strong anti-proliferative effect respectively. By employing molecular weight fractionation, we attempt to isolate specific components from the media retaining the strong interaction activity.

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 35. doi:1538-7445.AM2012-35
Abstract 3504: Generation and optimization of a chimeric antigen receptor against human CD22: A new immunotherapeutic agent for adoptive immunotherapy
Authors: Haso Waleed , Lee Daniel , Morgan Richard , Pastan Ira , Mackall Crystal , Orentas Rimas J.
Published: August 2012

CD22 is expressed on a number of hematologic malignancies. A recombinant immunotoxin composed of an anti-CD22 Fv fused to a 38 kDa fragment of Pseudomonas exotoxin A (Moxetumomab pasudodtox, HA22) is currently being evaluated in the treatment of B cell malignancies. We used the Fv sequence to construct a series of chimeric antigen receptors (CARs) to determine the optimal affinity, domain structure, and signaling required for optimal anti-leukemic activity. The original anti-CD22 binding domain, BL22, or a newer generation high-affinity domain, HA22, were fused to transmembrane and signaling sequences derived from the TCR zeta-chain, CD28, and CD137. In some constructs we extended the binding domain away from the membrane using constant domains from IgG (CH2CH3). Retroviral gene vectors were used to transduce activated primary T cells with CAR constructs. We found: HA22 Fv, 2 as opposed to 3 signaling motifs, and non-CH2CH3 containing CARs were superior in short-term in vitro tumor cell cytolysis assays, indicating that Fv affinity, signaling, and 3-D structure of the CAR all impact the anti-leukemic effectiveness of CARs. Finally, direct comparison to CD19-specific CAR showed an equivalent or superior killing activity in 2 out of 3 ALL lines tested. Using Scatchard analysis to define the number of CD22 molecules on the surface, the ALL line with the lowest number of CD22 molecules was also the least able to be killed by CAR-transduced T cells. The superior lytic activity of CD19-CAR for this single cell line was due to preservation of high levels of CD19 at the cell surface. We are currently testing the in vivo activity of anti-CD22 CAR in an immunodeficient mouse model bearing human cell lines and primary patient-derived ALL. Our results indicate that CD22-CAR should be developed for the immunotherapy of CD22+ malignancies.

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 3504. doi:1538-7445.AM2012-3504
Abstract 352: hnRNP A2/B1 regulates S1PR3 expression in lung cancer
Authors: Tauler Jordi , Siegler Jessica , Sun Xiaoguang , Moreno-Vinasco Liliana , Garcia Joe GN
Published: August 2012

Several clinical trials have shown that elevated expression of heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) in exfoliated bronchial epithelial cells correlates with eventual development of lung cancer. Cells with high levels of hnRNP A2/B1 expression have also been reported to manifest multiple molecular features of genetic injury. The hnRNPs are a complex group of RNA-binding proteins which play a key role in mRNA processing: stability, splicing, export and subcellular localization and participate also in telomere biogenesis. To elucidate the mechanism that links hnRNP A2/B1 overexpression with lung cancer progression we have knocked down hnRNPA2/B1 mRNA in non-small cell lung cancer (NSCLC) cell line A549 with a stable siRNA vector-based system. Silencing hnRNP A2/B1 increased proliferation and decreased migration in A549 and H1703 cell lines. These changes in migration and proliferation in A549 and H1703 hnRNPA2/B1-silenced cell lines correlated with an increase of E-Cadherin expression in both cell lines at mRNA and protein level. This increase in E-Cadherin expression was accompanied with a down-regulation of E-Cadherin inhibitors Twist1 and Snai1. We have proposed that hnRNP A2/B1 modulates epithelial-mesenchymal transition (EMT) in lung cancer cell lines that present a mesenchymal or intermediate phenotype such as H1703 and A549. It has been proposed that EMT may induce metastasis of cells with a mesenchymal phenotype. After metastatic seeding, EMT would be reversed trough mesenchymal-epithelial transition (MET) allowing tumor growth. However, mechanisms that regulate reversion of EMT are still poorly characterized. Interestingly, sphingosine 1-phospate (S1P) is an important angiogenic factor and regulator of vascular permeability. Microarray expression analysis revealed that silencing hnRNP A2/B1 decreases expression of the sphingosine 1-phosphate receptor 3 (S1PR3), a pro-migration RhoGTPAse activating S1P receptor, in A549 cells. Therefore, Moreover, S1P also stimulates motility of cancer cells through S1P receptors. It has been described that S1PR3 regulates migration and invasion in breast, prostate and gastric cancer. In A549 cells, S1PR3 is the most abundant receptor for S1P. Here we report that down regulation of hnRNP A2/B1, in lung cancer cells, decreases S1PR3 expression at the mRNA and protein level. We propose that further study of the mechanistic link between hnRNP A2/B1, S1P function and S1P receptors may allow a better understanding of the molecular mechanisms involved in invasion, metastasis. It may also provide new insights regarding the interaction between endothelial and epithelial cells and the regulation of EMT during tumor progression.

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 352. doi:1538-7445.AM2012-352
Abstract 3524: A novel approach to targeting mutated colorectal adenocarcinomas with T cell-engaging CEA/CD3-bispecific BiTE investigational antibody MEDI-565
Authors: Oberst Michael D. , Fuhrmann Stacy , Mulgrew Kathy , Amman Maria , Cheng Lily , Lutterbuese Petra , Richman Laura , Coats Steven , Baeuerle Patrick A. , Hammond Scott A.
Published: August 2012

Colorectal cancer (CRC) cells can harbor somatic mutations with strong impact on cancer cell signaling that limit the effectiveness of both chemotherapy and targeted therapies including monoclonal antibodies and kinase inhibitors. Therefore, novel therapeutic modalities are needed that are not impacted by the presence of such genetic mutations. We have here evaluated a CEA/ CD3-bispecific BiTE antibody termed MEDI-565 (also known as MT111) for its ability to redirect cytotoxic T cells for lysis in co-cultures and in xenograft models of human CRC lines harboring oncogenic mutations. Redirected lysis of CEA-positive tumor cells by MEDI-565 occurred in a manner dependent on CEA surface antigen density but independent of exogenously added soluble CEA. Importantly, the potency of lysis was independent of the mutational status of genes commonly mutated or lost in colorectal and other cancers, including frequent mutations in KRAS, BRAF, PI3KCA, PTEN and TP53 genes. In mouse xenograft models, the ability of MEDI-565 to inhibit tumor growth was likewise independent of the mutational status of the human tumor xenograft models. Our findings suggest that MEDI-565 warrants further clinical investigation as a potential treatment option for patients with CEA-positive tumors harboring somatic mutations that are less responsive to traditional chemotherapy or targeted agents.

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 3524. doi:1538-7445.AM2012-3524
Abstract 3527: Potent anti-tumor activity of AbGn-100, an anti-CD326 x anti-TCR bispecific antibody to CD326-expressing solid tumors
Authors: Chiang Evelyn , Lee Shu-Hua , Tsai Yu-Ying , Liu Meng-Ru , Hsieh Yu-Chi , Huang Chiu-Chen , Lin Shih-Yao
Published: August 2012

CD326 is one of the first and prominent immunotherapeutic targets in cancer therapy due to its frequent and high-level expression on most carcinomas of various origins. The dominant role of cytotoxic T cells for tumor suppression and surveillance in vivo is well documented in literature. A novel bi-specific antibody AbGn-100 was constructed, in which the antigen-binding domain of an anti- human CD326 antibody was linked to the antigen-binding domain of an anti-human T cell receptor (TCR) ≤ chain antibody. Human serum albumin was incorporated into this construct to prolong the half life in vivo. This bi-specific antibody is able to direct T cells toward CD326-expressing cancer cells to execute T cell cytotoxic function after TCR cross-linking mediated by CD326 expressed on cancer cells while it remains harmless when either T cells or CD326-expressing cancer cells is absent. In vitro cytotoxicity assays with PBMCs from different donors have demonstrated potent (up to 60% above the background) cytotoxicity eliciting activity of AbGn-100 to lung (NCI-H358), ovarian (OMC3) and colorectal (COLO205) cancer cells lines. In the absence of cancer cells, the addition of AbGn-100 didn't trigger the up-regulation of T cell activation markers such as CD25 or CD69, nor did it increase the secretion of cytokines such as IL-2 and Interferon β, demonstrating the safety profile of AbGn-100. In vivo activity of AbGn-100 was tested with established lung (NCI-H358) and ovarian (OMC-3) cancer xenografts in NOD-SCID mice. AbGn-100, in the presence of human PBMC, significantly reduced the size of the established lung and ovarian tumors. Most notably, in some of the mice, tumor was not detectable after 50 days of treatment, suggesting the possibility of tumor eradication. PK studies in mice showed the half-life of AbGn-100 to be around 20 hours, which is substantially longer than conventional single-chain Fv bi-specific antibodies. These data support the potential of further development of AbGn-100 as therapeutics for the treatment of CD326-expressing solid 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 3527. doi:1538-7445.AM2012-3527
Abstract 3530: Lipid accumulation inhibits DC ability for cross-presentation of antigens in tumor-bearing mice
Authors: Cao Wei , Koomen John M. , Gabrilovich Dmitry I. , Tyurin Vladimir A. , Kagan Valerian E.
Published: August 2012

Professional antigen presenting cells dendritic cells (DCs) play an important role in the initiation and maintenance of immune responses. Numerous studies have demonstrated defective function of DCs in cancer. However, the mechanisms of those defects remain not clear. Previously, we have demonstrated that DCs in tumor-bearing hosts accumulate lipids via up-regulation of the expression of scavenger receptor A (CD204). This resulted in inability of DCs to effectively process exogenous antigens. In this study we found that the DCs exposed to tumor-derived factors (TDF) in vitro or isolated from tumor-bearing (TB) mice had increased uptake of soluble protein ovalbumin (OVA). No defect in the activity of lysosomal and endosomal proteases was detected. Using mass-spectrometry we determined that TDF did not affect processing of OVA by DCs. At the same time, DCs exposed to TDF or isolated from TB mice expressed lower levels of OVA-derived peptide-MHC class I (pMHC) complexes and decreased ability to stimulate OVA peptide specific CD8+ T cells (OT1). Using lipid mass-spectrometry we found substantial accumulation of oxidized lipids in DCs obtained from TB mice or generated in vitro in the presence of TDF. To mimic accumulation of oxidized lipids in vitro, we treated bone marrow derived DCs with linoleic fatty acid (LA) and oxidized agent azobis-(2,4-dimethylvaleronitrile) (AMVN). DCs easily picked LA and form lipid bodies similar to the process observed in the presence of TDF. However, accumulation of LA did not result in defective processing of OVA-derived epitope as was determined by measuring the level of pMHC on DC surface and by stimulation of OT1 cells. AMVN at selected concentration also did not affect OVA processing and presentation. In contrast, combination of LA and AMVN significantly reduced the ability of DCs to process antigens associated with OVA. No changes in the expression of MHC class I and co-stimulatory molecules were observed. These data indicate that oxidized lipids accumulated in DCs in tumor-bearing hosts prevent cross-presentation of antigens, which may have important implications for DC ability to induce tumor-specific immune responses.

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 3530. doi:1538-7445.AM2012-3530
Abstract 3532: The effect of B cell depletion on tumor phenotype
Authors: Wakatsuki Kohei , Sheu Eric G. , Moore Francis D.
Published: August 2012

Introduction There are past indications that the adaptive immune response of B cells plays a role in tumor development. We examined this issue in vivo by examining the growth of Lewis Lung Carcinoma (LLC) and murine melanoma in B cell knockout (Bcell ko) mice. Methods Cultured LLC or melanoma cells were implanted into hindlimbs of C57BL/6 (B6) and Bcell ko mice. Tumors were measured every 3-4 days, and tissue was harvested for histological examination 2-3 weeks after tumor implantation. Tissues were stained with labeled anti-IgG, -CD4, -CD8, and -CD31 antibody. Results Melanomas in B6 and B cell ko mice enlarged at the same rate. However, tumor growth of LLC was significantly slower in B cell KO mice compared to B6 (p=0.02). Though both tumor-infiltrating CD4+ T cells and CD8+ T cells were identified in B6 mice, tumor-infiltrating CD4+ T cells but no tumor-infiltrating CD8+ T cells were seen in B cell KO mice in LLC. Angiogenesis was significantly inhibited in LLC in B cell KO mice. Conclusions The absence of B cells selectively inhibited tumor growth for LLC, and was associated with less tumor angiogenesis and an absence of CD8+ T cells. Blocking this aspect of the B cell response might be useful therapy for selected 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 3532. doi:1538-7445.AM2012-3532
Abstract 3536: Depletion of regulatory T lymphocytes reverses the imbalance between Pro- and anti-tumor immunities via enhancing antigen-specific T cell immune responses
Authors: Chen Yu-Li , Chang Ming-Cheng , Huang Chia-Yen , Chang Ying-Cheng , Chen Yun-Yuan , Wang Ju-Ming , Cheng Wen-Fang
Published: August 2012

Immunogenicity is the ability of antigens to elicit an immune response. The host immunity for anti-tumor can be induced because of the existence of tumor-specific and/or tumor-associated antigens. However, the most effective immune manipulation for ovarian carcinoma is eagerly awaited. To explore the systemically and locally kinetic changes of immunologic profiles during tumor progression and to elucidate the inhibition of tumor growth and the reverse of immunologic profiles by depletion of Treg cells in ovarian carcinomas, ovarian cancer patients and the ascitogenic animal model were employed. Immunologic profiles with flow cytometric analyses, immunohistochemistric staining, RT-PCR, ELISA, and ELISPOT assays were performed. In vivo depletion of Treg cells with the mAb PC61was also performed in the animal model. Including the anti-inflammatory cytokines IL-4 and TNF-α significantly decreased, TGF-β, IL-6, IL-10 significantly elevated in human ascites when the disease progressed to advanced diseases. The ratios of CD8+ T cell/Treg cell in the tumor asociated lymphocytes of the human ascites were lower in advanced diseases than those in early diseases. These alterations of immune components during tumor progression were proved in our animal model. Mice, when treated with kinetic low dose of mAb PC61, showed longer survival than the other groups. Tumor-bearing mice treated with kinetic low dose mAb PC61could inhibit the suppressive immunologic profiles, enhance the effective immunologic profiles, and generate potent antigen-specific anti-tumor immunities and effects. We concluded that the imbalance between effective and suppressive immunities could be identified in tumor-bearing situation, especially in advanced diseases. The depletion of Treg cells could correct the immunologic profiles and generate potent antigen-specific immunity. The strategy of targeting Treg cells can be a new strategy for the immunotherapy of ovarian carcinoma.

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 3536. doi:1538-7445.AM2012-3536
Abstract 3543: Complete regression of solid B16F1 melanoma tumors obtained by intratumoral injection of LTX-315 (Oncopore®)
Authors: Camilio Ketil A. , Rekdal Oystein , Sveinbjornsson Baldur
Published: August 2012

Background: Malignant melanoma is imposing an increasing threat to the world's population and new therapies are needed.Standard treatment involves surgery, chemotherapy, and radiation therapy and often leads to relapse after ended therapy. LTX-315 (Oncopore®) is a chemically modified cationic cytolytic peptide which is equally active against drug-sensitive and drug-resistant cancer cells. Earlier animal studies have demonstrated that treatment of syngeneic murine A20 B-cell lymphomas and CT26WT colon carcinomas with intratumoral (i.t.) injection with LTX-315 resulted in complete tumor regression and long-term protective effect against re-inoculated tumor cells. The present study was undertaken to investigate whether LTX-315 induced an antitumor response in vivo in a highly aggressive murine melanoma tumor model. Methods: Pre-cultured B16F1 melanoma cells (5 x 104) were subcutaneously inoculated into the abdomen of syngeneic C57BL/6N mice and established tumors treated i.t. with LTX-315. Animals were taken for analysis to elaborate the mechanism of action of LTX-315 and for potential immune modulatory effects following treatment. Blood plasma was analyzed for changes in cytokine content and tumor tissue was analyzed for infiltrating immune cells using immunohistochemistry and flow-cytometry. Results: Intratumoral treatment with LTX-315 resulted in a complete regression of tumor in the treated animals. Tumors treated with LTX-315 showed an increased infiltration of immune cells into the tumor compared to control tumors receiving vehicle. Conclusions: Our results suggest that LTX-315 treatment can induce complete regression in solid B16F1 melanoma tumors, thus leading to local tumor control. Intratumoral treatment with LTX-315 can lead to immune-modulatory effects such as an increase in the number of infiltrating immune cells, causing a shift in the balance between immune effector and immune suppressive cells in the tumor environment.

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 3543. doi:1538-7445.AM2012-3543
Abstract 3553: Modulation of pro-inflammatory signaling pathways by aging T-lymphocytes contributes to a more malignant phenotype in prostate epithelial cells
Authors: Alejandra De Angulo , Faris Robert , Cavazos David , deGraffenried Linda , Jolly Chris
Published: August 2012

Prostate cancer risk is determined largely by age. While some studies have suggested that the slow growing rate of prostate cancer is responsible for the link between aging and prostate cancer, the role of aging T-cells in prostate cancer development remains largely unknown. The objective of this study is to determine how age-related changes in T-lymphocyte function contribute to prostate tumorigenesis. We hypothesized that age related changes in T-lymphocyte function, to a pro-inflammatory phenotype may promote prostate cancer development. For our studies we used the GPAT-1 KO mice model. The GPAT-1 KO mice have T-lymphocytes that mimic aged T-cells. Preliminary data shows that, in agreement with what has been seen in human aged T-cells, aging-mimic GPAT-1 KO T-lymphocytes generate more pro-inflammatory cytokines than T-lymphocytes from age matched wild-type mice. These cytokines turn on inflammatory pathways that stimulate proliferation, tissue disruption and tumor growth. A cytokine array was used to detect the relative protein levels of 40 different cytokines and chemokines in the sera from either young GPAT-1 knockout (KO), young wild-type (WT) or old mice (22 months). We observed a shift to a more pro-inflammatory cytokine profile in the GPAT-1 KO and old mice. Many of the same cytokines that were elevated in the sera from the old and GPAT-1 KO mice, such as IL-17 and IL-6, are also implicated in promoting prostate tumorigenesis primarily through induction of other inflammatory cytokines and transcription factors such as, NF-kB and STAT3. The objective of this study was to determine if the increased levels of pro-inflammatory cytokines in the sera from the GPAT-1 KO mice correlates to a more malignant phenotype in prostate epithelial cells. Malignancy in epithelial cells was assessed by the following phenotypical changes: Immortalization, anchorage independence, proliferation and invasiveness. Exposure to sera from the GPAT-1 KO mice promoted phenotypical changes in epithelial cells that are indicative of early tumorigenesis. Taken together our data suggests that pro-inflammatory cytokines in the sera from mice with aging T-lymphocytes may turn on pro-inflammatory pathways that contribute to a more malignant phenotype in prostate epithelial cells. This is the first study to use the GPAT-1 KO mice model to explore the relationship between aging T-lymphocytes, inflammation and prostate 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 3553. doi:1538-7445.AM2012-3553