bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-247: Regulation signatures consistently detect activity of EGFR pathway in different cell lines
Authors: Dezso Zoltan , Webb Craig , Miller Jeremy , Cherba David , Bugrim Andrej
Published: February 2011

In this work we introduce a concept of “regulation signatures” which aims to overcome shortcomings of existing methods of molecular diagnostics. In this approach we utilize our recently developed methodology for identifying key regulatory proteins in biological networks. The procedure works by combining high-throughput molecular data from individual biological samples with the knowledge-base on the global network of protein interactions. The algorithm performs scoring of signaling proteins in the global network to identify those that most likely represent key regulators responsible for observed downstream changes in gene and protein expression. Using these scores we construct “regulation signatures” - sets of proteins that characterize core cell signaling activity associated with a condition of interest. In the present study we illustrate this approach by building a signature for the EGFR pathway activation using gene-expression profiles from different cell lines stimulated with EGF. We demonstrate that our algorithm consistently predicts activity of the EGFR pathway despite significant variation in gene expression profiles across different samples. We also illustrate that this signature can detect signaling patterns associated with constitutive RAS activity. We discuss how regulation signatures could be applied to develop more accurate, robust and mechanistically relevant methods for predicting drug sensitivity, disease progression, and other clinical end-points.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-247.
Abstract LB-248: Towards a global picture of breast cancer: transcriptional networks, pathways, regulators, and validation
Authors: Zhang Bin , Tran Linh , Jonathan Derry , Zhu Jun , Friend Stephen
Published: February 2011

The unprecedented volumes of large-scale genomic and genetic data being generated today, combined with the poor understanding of the genetics underlying complex biological systems, demand a systems biology approach to identify a global landscape of interactomes that contribute to a variety of clinical endpoints such as tumor progression. Along this direction, two kinds of gene network analyses, association (gene coexpression network) and causality inference (Bayesian network), have been almost independently developed in the past decade. In spite of the significant success of the methods, it is still far away from generating a clear picture for even a single pathway involved in complex human disease like cancer due to insufficient information and various limitations of the methods. Here we present a framework to combine the two types of network analyses with an aim of integrating many high-throughput gene expression datasets on multiple platforms. By applying the integrative network approach to four large scale microarray datasets in breast cancer, we first systematically uncover gene modules/pathways involved in breast cancer progression through a weighted gene coexpression network analysis, then use these gene modules to partition a complex Bayesian network constructed from the same datasets, and finally identify key regulators of the modules predictive of outcomes. A significant portion of the predicted novel gene targets are validated through a large number of siRNA experiments in breast cancer cell lines. This allows us to globally validate breast cancer gene networks. The integrative approach and the findings will have a significant impact on breast cancer research and drug development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-248.
Abstract LB-253: Mesenchymal stem cells of fallopian tube cancers are specifically attracted by mature ovulating follicles: implication of fallopian tube origin of serous ovarian carcinoma
Authors: Yeh Ching-Hua , Lin Shih-Rung , Chu Tang-Yuan
Published: February 2011

Background: Recent studies of surgical specimens resected from carriers of breast ovarian cancer syndrome have suggested a fallopian tube origin of serous carcinoma of the ovary. We tested the following hypothesis: Cancer initiating cells arising from fallopian tube home to ovulation wound via chemotaxis of follicular fluid.

Materials and Methods: Mesenchymal stem cells from fallopian tube cancers (FTC-MSC) and normal fallopian tubes (FT-MSC) were respectively culture-isolated from two patients with FIGO stage 3C serous adenocarcinoma of fallopian tube and three patients with uterine myoma. Tissues were digested with collagenase type I and dispase and cells were grown in anti-oxidant DMEM medium containing 5% fetal bovine serum. Characteristics of stem cells including cell surface markers, colony formation, trans-differentiation and hTERT expression were analyzed. Follicular fluids and cells were procured and cultured from ovulating women receiving in-vitro fertilization program. Chemotaxis and cell migration activities were studied by trans-well migration assay and wound healing assay.

Results: The isolated FTC-MSC had a doubling time of around 25h and gave a typical mesenchymal stem cell phenotypes with anchorage independent growth, lack of gap junction communication, positive for CD24, CD44, CD133, CD29, CD90, CD56, CD117 and CD146, negative for CD 34 and CD45, and had high hTERT expression. Capabilities of osteogenic and adipogenic differentiation and chemo-resistence paclitaxol and cisplatin were evident. FTC-MSC but not FT-MSC highly responded to mature, ovulating follicular fluid, and to condition media of cultured follicular cells or ovarian stromas, and much less to those derived from immature follicles, and to conditional media of endometrial, cervical and peritoneal cells in culture.

Conclusions: The highly specific chmotaxic effect of mature, ovulating follicles to FTC-MSC supports the hypothesis of fallopian tube origin of serous ovarian carcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-253.
Abstract LB-254: Efficiently targeting cancer stem cells requires tactical activation from their dormant state and subsequent exhaustion
Authors: Lin Edward H. , He Xi C. , Yan Xiaowei , Deng Yanhong , Yeung Raymond , Gu Jian , Curley Stephen , Haug Jeff , Blau Anthony , Wu Xifeng , Tian Qiang , Li Linheng
Published: February 2011

Akin to normal tissue stem cells (NTSCs), cancer stem cells (CSCs) may have adopted dual active-dormant mechanisms to respectively sustain growth while eluding exhaustion from conventional chemotherapy such as 5-fluorouracil (5-FU). How to effectively target dual active-dormant CSCs while preserving NTSCs is essential to curing cancers. We compared the kinetic states of NTSCs in gut and bone marrow as well as leukemia stem cells following 5-FU treatment and found a narrow window of opportunity when forcibly activated dormant NTSC/CSCs can be targeted following depletion of proliferating progeny. Given that stemness factors predict poor overall survival (OS) in many cancers, we proposed a novel two-step ADAPT strategy_activate from dormancy and potentiate subsequent targeting_ in an attempt to synchronize cytotoxic effects of 5-FU on proliferating cells with stemness inhibitors targeting activated CSCs respectively. We applied the two-step protocol using capecitabine, an oral 5-FU prodrug, and celecoxib, a selective COX-2 inhibitor that is also a stemness inhibitor (it down-regulates LGR5/6, CD133, Oct4/Sox effectors, ALDH, CD24, Wnt, Sonic Hedghog) in patients with unresectable metastatic colorectal cancer. We found that the ADAPT strategy resulted in complete or near complete response rate in 27 patients with surgically unresectable metastatic colorectal cancer, especially if coupled with radiation. The median survival for this group of patients reached 92.7 months (95% CI, 53.5 months - not reached). Paradoxically, patients who had confirmed complete response without surgery but with long-term ADAPT therapy enjoyed 100% 5-year relapse free survival compared to 42% of patients who had undergone surgical resection of metastasis (p=0.04 log rank). Intriguingly, Celecoxib exerted many opposite biologic effects compared to 5-FU on cell cycle, apoptosis, DNA repair/synthesis, particularly stemness genes/pathways, and thus produced conflicting effect in short-term colon cancer cultures when combined with 5-FU. This observation potentially explains the 6 months gain in OS in the responding patients and the lack of OS for all patients in reported phase III BICC-C study that randomized Celecoxib vs placebo with 5FU based chemotherapy.. Thus, optimal ADAPT strategy to target CSCs requires initial cytoreduction of proliferating progeny and activation of dormant/drug-resistant CSCs, and subsequent cyclical exhaustion via long-term exposure to stemness inhibitors along with intermittent cytotoxic agents such as 5-FU.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-254.
Abstract LB-257: c-Met: a new cancer stem cell marker and therapeutic target for pancreatic cancer
Authors: Li Chenwei , Hynes Mark , Dosch Joseph , Wu Jing-Jiang , Sarkar Bedabrata , di Magliano Marina Pasca , Simeone Diane M.
Published: February 2011

Pancreatic adenocarcinoma is a highly aggressive disease which is usually diagnosed in an advanced state and for which there are little/no effective therapies. The growth of many cancers depends on a subpopulation of self-renewing cells, termed cancer stem cells (CSC). We have previously identified such a CSC population in human pancreatic cancers which possess the cell surface marker phenotype CD44+CD24+ESA+. C-Met, a member of the receptor tyrosine kinases (RTKs) family and receptor for the hepatocyte growth factor (HGF) ligand, has been recently described as a marker of normal mouse pancreatic stem/progenitor cells. We hypothesized that c-Met may function as a cell surface marker and therapeutic target for human pancreatic CSCs. Studies were performed in low passage primary human pancreatic adenocarcinoma xenografts (n = 3) established in NOD-SCID mice. Self-renewal capacity of c-Methigh pancreatic cancer cells was assessed using in vitro sphere assays and in vivo tumorigenicity of c-Methigh pancreatic cancer cells was evaluated by cell implantation in NOD/SCID mice. In vitro studies demonstrated that c-Methigh cells formed spheres in non-adherent cultures, while c-Met− cells did not. Use of the c-Met inhibitor XL184 or c-Met knockdown with shRNA significantly inhibited tumor sphere formation. Pancreatic cancer cells expressing high c-Met had increased tumorigenic potential in vivo and cells expressing both CD44 and c-Methigh, representing 0.5-5% of pancreatic cancer cells, demonstrated the highest tumorigenic potential of all populations studied to date. C-Methigh CD44+ expressing pancreatic cancer cells demonstrated the capacity for self-renewal and production of differentiated progeny, properties that define CSCs. Further, c-Met inhibition of established primary human pancreatic tumors in NOD/SCID mice significantly inhibited tumor growth and depleted the pancreatic CSC population, when used alone or in combination with gemcitabine. Inhibition of c-Met also prevented the developmental of metastases using an intracardiac injection model. In this report, we define c-Met as a new marker for pancreatic CSC and define c-MethighCD44+ cells as a highly tumorigenic pancreatic CSC population. Our data also indicate that targeting c-Met may be useful in eradicating a CSC population and inhibiting the development of metastases.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-257.
Abstract LB-26: Translational up-regulation of Aurora-A in EGFR-expressed cancer
Authors: Hung Liang-Yi
Published: February 2011

Abnormal expression of Aurora-A and EGFR is observed in different kinds of cancer and associated with poor prognosis in cancer patients. However, the relationship between Aurora-A and EGFR in tumor development was not clear. In previously report (Nucleic Acids Res, 2008, 36:4337-4351), we found EGFR translocates to nucleic to activate Aurora-A expression after EGF treatment in EGFR-overexpressed cells. However, we also observed that not all the EGFR-overexpressed cells have the nuclear EGFR pathway to mediate the Aurora-A expression. In this study, we demonstrated that EGF signaling increased the Aurora-A protein expression in EGFR-overexpressed colorectal cancer cell lines via increasing the translational efficiency. In addition, the overexpression of EGFR was also associated with higher expression of Aurora-A in clinical colorectal samples. Activation of the PI3K/Akt/mTOR and MEK/ERK pathways mediated the effect of EGF induced translational up-regulation. Besides, only the splicing variants containing exon 2 of Aurora-A mRNA showed increased interaction with the translational complex to synthesize Aurora-A protein under EGF stimulus. Besides, the exon 2 containing splicing variants were the major Aurora-A splicing form expressed in human colorectal cancers. Taken together, our results propose a novel regulatory mechanism for the abnormal expression of Aurora-A in EGFR-overexpressed cancers, and highlight the importance of alternative 5′-UTR splicing variants in regulating Aurora-A expression. Furthermore, the specific expression of exon 2 containing splicing variants in cancer tissues may serve as a potential target for cancer therapy in the future.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-26.
Abstract LB-261: Cancer stem cell characteristics exhibited by doxorubicin-selected drug-resistant breast cancer cells
Authors: Calcagno Anna Maria , Salcido Crystal D. , Gillet Jean-Pierre , Wu Chung-Pu , Fostel Jennifer M. , Mumau Melanie , Gottesman Michael M. , Varticovski Lyuba , Ambudkar Suresh V.
Published: February 2011

Background: Cancer stem cells (CSCs) are presumed to possess the virtually unlimited ability to proliferate while preserving self-renewal. These cells are also highly resistant to chemotherapeutics, a feature which correlates with overexpression of ATP-binding cassette (ABC) transporters. No reports to our knowledge have shown that prolonged continuous selection of cells for drug resistance enriches cancer stem-like cells.

Methods: We examined parental and drug-selected breast cancer cell lines to determine whether there is a relationship between drug resistance and the presence of cells with a CSC phenotype. MCF-7/ADR cells, generated from weakly tumorigenic parental MCF7 cells by continuous exposure to increasing concentrations of doxorubicin, were examined by microarray analysis, flow cytometry, invasion, in vivo tumorigenicity and other CSC characteristics. The putative CSC population was also examined for expression of multidrug resistance (MDR) genes using TaqMan Low Density Arrays.

Results: Pathway analysis showed that MCF-7/ADR cells express ABCB1 as well as genes with patterns similar to breast CSCs. MCF-7/ADR cells grow in 3D cultures as mammospheres, are highly invasive and tumorigenic. In contrast to parental cells, over 30% of MCF-7/ADR cells are CD44+/CD24-. The CD44+/CD24- cells have the ability to self-renew and overexpress many MDR genes when compared to the CD44+/CD24+ population. No enrichment in CD44+/CD24- or CD133+ populations was detected in MCF-7/MDR or other cells with forced expression of the ABCB1 transporter or MDR genes.

Conclusions: Cells with characteristics of CSCs increased in number following selection for doxorubicin resistance. Based on our findings, we speculate that prolonged drug treatment in vivo may result in expansion of a CSC-like population.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-261.
Abstract LB-281: Inhibition of Hedgehog results in altered regulation of c-jun and of ERCC1 in cisplatin-resistant A2780-CP70 human ovarian cancer cells
Authors: Kudo Kenji , Gavin Elaine , Das Shamik , Denny Wesley , Jasmin Martine , Shevde-Samant Lalita , Reed Eddie
Published: February 2011

Cancer stem cells are presumed to be highly resistant to chemotherapy. Activation of the Hedgehog pathway has been reported as necessary, for the cancer stem cell state. A key gene in the Hedgehog pathway is Gli1. Resistance to platinum compounds is due in part, to up-regulated nucleotide excision repair, NER. ERCC1 is a key marker for NER activity. Transcriptional control of ERCC1 occurs in part, through c-Jun. Upon treatment with cisplatin, cisplatin-resistant A2780-CP70 cells normally up-regulate c-jun and c-fos, which then up-regulate ERCC1 and other NER genes. More specifically, the c-jun Ser63/73 cascade is up-regulated, with up-regulation of activator protein 1 (Reed, JBC 1998). We studied the relationship between Gli1 expression, ERCC1 expression, and cisplatin resistance in the human ovarian cancer cell lines A2780 and A2780-CP70. A2780-CP70 cells are 10-15 fold more resistant to cisplatin than A2780 cells. We used two different probes to modulate the Hedgehog pathway: a) cyclopamine as a pharmacologic inhibitor of the Smoothened; and, b) an anti-Gli1 shRNA to specifically inhibit Gli1. At baseline, cisplatin-resistant cells, expressed > 10-fold more Gli1 protein than cisplatin-sensitive cells. In cisplatin-resistant cells, Gli1 protein was down-regulated in response to cyclopamine, and to anti-Gli1 shRNA. When A2780-CP70 cisplatin-resistant cells are pretreated with cyclopamine, or anti-Gli1 shRNA, the following events occur. The c-jun Thr91/93 cascade is upregulated, which is associated with pro-apoptotic processes. The c-jun Ser63/73 cascade is suppressed. This cascade is associated with pro-growth processes. If cisplatin is given after cyclopamine or anti-Gli1 pretreatment; Gli1 protein is down-regulated; the c-jun Thr91/93 cascade is upregulated; the c-jun Ser63/73 cascade is suppressed; and cells do not up-regulate ERCC1, XPD, or XRCC1. Thus, the normal cisplatin-induced up-regulation of these three genes involved in NER (ERCC1, XPD) and in base excision repair (XRCC1), is suppressed by suppression of the Hedgehog pathway. We conclude that Gli1 and/or other genes involved in the Hedgehog pathway (which is critical for cancer stem cells), may play key roles in the up-regulation of DNA repair genes, specifically in response to DNA damaging agents such as cisplatin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-281.
Abstract LB-285: Pharmacogenomic study to improve sorafenib response in hepatocellular carcinoma
Authors: Kassner Michelle , Kiefer Jeff , Tang Nanyun , Barrett Michael , Han Haiyong , Von Hoff Daniel , Borad Mitesh , Yin Holly
Published: February 2011

Hepatocellular carcinoma (HCC), the primary malignancy of the liver, is the fourth leading cause of cancer deaths worldwide, with a 5-year survival rate of∼10%. Recently, a new multikinase inhibitor, sorafenib (Nexavar®), which mainly targets the VEGFR and the Raf/Mek/Erk pathways, has shown limited response rate and modest survival benefits in patients with advanced stage HCC. We hypothesize that there exist genetic alterations or contexts of vulnerability (COV) in cancer cells that dictate sensitivity to sorafenib. In order to identify specific COVs and obtain an increased understanding of drug's mechanism of action, we performed a custom chemosensitization high-throughput siRNA screen. We developed and optimized a sorafenib chemosensitization assay in 3 HCC cell lines, one of which, Hep3B, a AFP and HBsAg positive cell line, was selected for primary RNAi screening with a kinase siRNA library, which covers 700 genes (4 siRNA sequences per gene). Primary screen data was rigorously evaluated for multiple quality control metrics (transfection efficiency, CV values, accessing plate-to-plate and set-to-set variation) and found to exceed all expected performance parameters. The top sorefenib sensitizing hits were identified and supplemented with additional genes selected based on related biological concepts. This sensitization effect of the genes was further tested and compared in two additional HCC cell lines (HepG2 and PLC). Additionally, based on the sensitizer list from the RNAi screening, 11 chemical compounds were tested for synergistic combination with sorafenib. Notable synergism with sorafenib was observed in the combination with erlotinib or doxorubicin. More strikingly, we also observed synergy between sorafenib and multiple MEK inhibitors as well as gemcitabine in the selected HCC cell lines. Our data suggest that MEK inhibitors might improve the efficacy of sorafenib in HCC treatment in the clinic. Further mechanistic studies are being conducted for this particular combination.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-285.
Abstract LB-294: Development and characterization of novel orally available hypoxia-inducible factor (HIF) signaling inhibitors as dual-mechanism cancer therapeutics
Authors: Schultes Christoph , Alonso Jorge , Encinas-Lopez Arantxa , Leber Blanka , Mülbaier Marcel , Wawro Sabine , Janssen Bernd , Lewis Joe
Published: February 2011

The HIF signaling pathway is a crucial way in which tumors can circumvent the constraints of regions of low oxygen (hypoxia) to induce angiogenesis and maintain proliferation. The oxygen regulated subunit of the transcription factor hypoxia-inducible factor 1 (HIF1), HIF1αlpha, is a positive factor in tumor growth and its expression has been correlated with poor patient prognosis in a number of settings.

We here present in vitro and in vivo data for a novel series of orally available small-molecule HIF signaling modulators that show nanomolar inhibition of the HIF signaling pathway in addition to potent anti-proliferative activity against a large number of cell lines derived from solid and blood tumors (EC50 in the range 1-100nM). Phenotypically, the compounds elicit an initial G2/M arrest, followed by the induction of caspase-3/7 and the onset of apoptosis.

The in vitro results also translate into in vivo animal models. The lead compounds from the series show efficacy in tumor xenograft mouse models, with dose-dependent tumor growth inhibition of 60-70% after oral dosing (MDA-MB-231 xenograft). Structural optimisation has additionally allowed us to improve the PK and physicochemical characteristics of the compounds, with a lead candidate currently in formal pre-clinical development with the aim of entering a Phase 1 clinical trial in multiple myeloma at the end of 2010.

In conclusion, we believe that the development towards clinical Proof-of-Concept of this new class of dual-mechanism inhibitors of HIF signaling and cell proliferation presents a promising new option for cancer therapeutics.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-294.
Abstract LB-302: Activity of PF-04691502, A dual PI3K/mTOR inhibitor in breast cancer cell lines and models discriminates between ER, PR and HER2 positive and negative segments
Authors: Yuan Jing , Van Lee Nathan , Pavlicek Adam , Ching Keith , Cao Joan , Garza Scott , Hook Kenneth E. , Ozeck Mark , Marx Matthew A. , Christensen James G. , Kan Julie L.C.
Published: February 2011

The PI3K pathway plays a role in key cellular functions that include regulation of cell growth, proliferation, survival, angiogenesis, and motility. PI3K/AKT pathway aberrations are common in cancer comprising PTEN loss of function through mutations, deletion, and methylation events and gain of function at the PIK3CA locus including mutations and amplification events resulting in deregulation of this pathway. Thus, pharmacological intervention of this pathway should impact cellular functions central to survival of cancer cells. PIK3CA mutations/amplification and PTEN loss of heterozygosity have been reported to occur in approximately 35-40% and 20% of breast cancer, respectively and suggest this patient population could benefit from treatment using a small molecule inhibitor that targets the PI3K pathway. PF-04691502 which is a potent inhibitor of all PI3K isoforms and mTOR (TORC1 and TORC2) presently in Phase 1 trials was evaluated for its growth inhibitory or cytoreductive activity over a panel of 30 breast cancer cell lines. PF-04691502 had robust <300nM (IC50%) antiproliferative activity across the panel of breast cell lines. We observed a trend whereby cell lines that were hormone receptor (ER and/or PR) and HER2 negative (triple negative) were least sensitive and cell lines that were HER2(+) and/or hormone receptor positive (ER and/or PR) were more sensitive to PF-04691502. These studies were extended in vivo with PF-04691502 as a single agent and in combination in a HER2, ER and PR positive xenograft model with robust tumor growth inhibition in combination with docetaxel or with the pan-HER inhibitor, PF-00299804. In a xenograft that was triple negative, administration of single agent PF-4691502 at the MTD resulted in 60% tumor growth inhibition. In conclusion, our findings suggest that the ER/PR and/or HER2 positive breast cancer segment may particularly benefit from PI3K/mTOR inhibitor based treatment regimens.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-302.
Abstract LB-314: Patients with inflammatory breast cancer have significant reductions in immune cells responsible for adaptive immunity
Authors: Lee Bang-Ning , Gao Hui , Cohen Evan N. , Andreopoulou Eleni , Jackson Summer A. , Parker Charla , Tin Sanda , Galland Matthew , Ueno Naoto , Valero Vicente , Alvarez Ricardo H. , Cristofanilli Massimo , Reuben James M.
Published: February 2011

Background: Cell-mediated immunity is essential for maintaining immune surveillance against tumor progression. Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer, yet there is a paucity of information on peripheral blood leukocyte immunophenotypes of these patients. Therefore, we enumerated the immune cells of IBC patients with or without metastasis.

Methods: This ongoing prospective study consists of 43 IBC patients, 22 with non-metastatic IBC and 21 with metastatic disease (MIBC). Peripheral blood was collected prior to starting a new therapy and analyzed to determine the immunophenotype of T cells, B cells, regulatory T (TR) cells, natural killer cells (NK), and dendritic cells (DC) by 6-color flow cytometry. The Kruskal-Wallis and Mann-Whitney U tests were used to determine the differences between healthy donors (HD, N=15), non-metastatic IBC and MIBC patients.

Results: Among the 43 IBC patients, 22 are hormonal receptor (HR)+ with 11 HER-2+, 8 are HR- but HER2+, and 13 are triple receptor negative. Non-metastatic IBC patients have significantly lower median percentages (%) of lymphocytes (P=0.018), B cells (P=0.028), and myeloid DC (P=0.049), and higher median % TR cells (P=0.039) when compared with those of HD. In addition, non-metastatic IBC patients have significantly lower median counts of B cells (P=0.003), myeloid DC (P=0.009), and plasmacytoid DC (P=0.037) when compared with those of HD. Moreover, compared with non-metastatic IBC patients, MIBC patients were significantly older (P=0.029) and have significantly lower median % and absolute counts of lymphocyte and B cells (all P<0.02), lower median ratio of CD4+/CD8+ T cells (P=0.028), and lower median number of TR cells (P=0.013).

Conclusion: This preliminary cross-sectional analysis suggests that non-metastatic IBC patients have significant reductions in various effector cells, in particular, B-cells and antigen-presenting DC that may lead to compromised adaptive immunity. Moreover, metastatic IBC patients are more immunocompromised than non-metastatic IBC patients. Longitudinal study is warranted to further assess the role of humoral and cell-mediated immunity in the pathogenesis of IBC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-314.
Abstract LB-321: Changing the route of immunization determines outcome in immunotherapy of experimental brain tumors: Translation in development
Authors: Darabi Anna C. , Sande'n Emma , Eberstål Sofia , Janelidze Shorena , Visse Edward , Siesjö Peter
Published: February 2011

Introduction: Based on our previous experimental result we have performed a clinical trial at the Lund University Hospital, with immunotherapy using IFN transduced autologous tumor cells for intradermal (i.d.) immunizations in adult patients with glioblastoma multiforme. Eight patients have been treated with an increase in overall survival by more than six months as compared to age-matched controls. The trial has shown that the therapy has no side effects and that an immune activation can be detected. Current experimental results show that by changing the route of immunization from i.d. to sub-cutaneous (s.c.) immunization, a substantial increase in survival time of animals is seen. The mechanisms behind this are now under investigation.

Experimental Procedures: We are currently investigating the therapeutic efficacy of i.d. or s.c. administerd IFN transduced irradiated tumor cells (N32-IFNγ) against intra cerebral tumors in the rat glioma model (N32) syngeneic with the Fisher 344 rat. The rats are immunized day 1, 15 and day 29 after tumor inoculation. The induction of the immune response is studied by tracing irradiated CFDA-SE stained tumor cells from the immunization site (i.d. or s.c.) to secondary lymphoid organs using immuno-histochemistry. The immune response is studied at different time-points after the first and after the third immunization.

Preliminary Results: S.c. immunization with N32-IFNγ cured 53% of the tumor bearing animals compared to i.d. immunization where only 6% of the rats survived for 100 days, when the study was finalized. After the first immunization, tumor cell debris can be traced to inguinal lymph nodes of i.d. immunized animals, but not of s.c. immunized animals. After the third immunization tumor debris is found in inguinal lymph nodes both after i.d. and s.c. immunization. No other secondary lymphoid tissues tested contain tumor debris. Mononuclear phagocytes expressing MHC class II are responsible for engulfing tumor cells at the immunization site of both i.d. and s.c. immunized animals. Cells that strongly express the enzyme cyclooxygenase-2, the rate-limiting enzyme for production of prostaglandine E2, are seen after s.c. immunization but not after i.d. immunization. Further studies are ongoing to reveal possible differences in kinetics and antigen presenting cells.

Conclusions: To our knowledge, no systematic comparison has been performed between different immunization routes using whole tumor cells as immunogen. If these results are further confirmed, the route of immunization will be altered from i.d. to s.c. in future clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-321.
Abstract LB-322: A modified HER2/neu peptide vaccine (2L9V-GP2) demonstrates enhanced CD8+ T cell recognition and stimulation in breast cancer patients at high risk for recurrence
Authors: Patil Ritesh , Clifton Guy T. , Clive Kevin , Tyler Josh , Zacharia Athina , Jama Yusuf , Mursal Mohamed , Ciano Kathy , Holmes Jarrod P. , Mittendorf Elizabeth A. , Peoples George E. , Ponniah Sathibalan
Published: February 2011

Introduction: The affinity between tumor-associated antigens and MHC Class I complexes directly affects the degree of CD8+ T cell (CTL) response. GP2 (IISAVVGIL, p654-662) is a HER2/neu-derived peptide, that has poor binding affinity to HLA-A2 (A2) and HLA-A3 (A3). We conducted a preclinical study to determine if amino acid substitutions in the GP2 peptide, predicted to increase binding affinity to A2 and A3, enhance CTL recognition and stimulation.

Methods: Based on computer modeling algorithms (BIMAS, SYFPEITHI), two GP2 peptide variants were predicted to have higher binding affinity to A2: SPA-12(2L9V-GP2) and SPA-13(2L5L9V-GP2). Freshly isolated PBMCs were obtained from randomly chosen, disease-free, node positive (NP) and high risk node negative (NN) breast cancer (BCa) patients, who had completed standard adjuvant therapy and are enrolled in the E75 vaccine booster trial. Peptide-specific CD8+ T cells were measured by HLA-A2: IgG dimer (A2 pts) and by interferon-γ ELISPOT (A2, A3 pts) assays. Groups were compared by t-test (dimer) and Mann-Whitney U (ELISPOT) tests.

Results: Thirty-five A2 (21 NP, 14 NN) and thirteen A3 (13 NP) samples were included in the study. Among A2 pts, the mean level of SPA-12-specific CTLs was greater than the GP2- (2.8±0.3% vs. 1.7±0.1%, p<0.001) and SPA-13-specific CTLs (2.8±0.3% vs. 1.1±0.1%, p<0.001). The level of SPA-13-specific CTLs was less than GP2-specific CTLs (p<0.001). For both A2 and A3 pts, the median number of IFN- producing cells was greater in response to SPA-12 (144, range 0-799 spots/105 cells) compared to GP2 (88, range 0-432 spots/105 cells, p=0.03) and SPA-13 (0, range 0-344 spots/105 cells, p<0.001). Again, the response to SPA-13 was less than GP2 (p=0.001). In addition, the NP A2 pts demonstrated a more robust CD8+ T cell response to SPA-12 compared to the NNs, both by HLA-A2: IgG dimer (3.2±.5 vs 2.2±0.2, p=0.05) and ELISPOT assay (223, range 0-799 vs 65, range 0-548 p=0.003). Nodal status did not have any significant bearing on the responses to GP2 and SPA-13.

Conclusion: The substituted sequences SPA-12 (2L9V-GP2) and SPA-13 (2L5L9V-GP2), both have higher predicted binding affinity to A2 and A3 than GP2. While SPA-12 showed significantly increased recognition and functional CTL responses compared to GP2, SPA-13 demonstrated lower responses. These data suggest that SPA-12 may be a more effective cancer vaccine than GP2, particularly in NP BCa patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-322.
Abstract LB-326: Synergistic therapeutic effects of cytokine-induced killer (CIK) cell and temozolomide against glioblastoma
Authors: Jin Younggeon , Jin Juyoun , Joo Kyeung Min , Lee Se Jeong , Jo Mi-young , Kim Yonghyun , Nam Do-Hyun
Published: February 2011

The presence of active immunity within the brain supports the possibility of effective immunotherapy for glioblastoma (GBM). To provide a clinically-relevant adoptive immunotherapy for GBM using ex vivo expanded cytokine-induced killer (CIK) cells, the treatment capability of CIK cells, either alone or in combination with temozolomide (TMZ) were evaluated. Human CIK (hCIK) cells were cultured from PBMC using activating anti-CD3 antibody and IL-2, which were 99% CD3+, 91% CD3+CD8+ and 29% CD3+CD56+. In vitro, hCIK cells showed tumor-specific cytotoxicity against U-87MG human GBM cells. When hCIK cells were injected into tail veins of immune-compromised mice bearing U-87MG tumors in their brains, numerous CIK cells infiltrated into the brain tumors. CIK treatments (1 × 105, 1 × 106 or 1 × 107, once a week for four weeks) inhibited the tumor growth significantly in a dose-dependent manner; 44%, 54% and 72% tumor volume reduction, respectively, compared with the control group (P < 0.05). Moreover, hCIK cells (1 × 107, once a week for four weeks) and TMZ (2.5 mg/kg, daily for 5 days) combination treatment further increased tumor cell apoptosis and decreased tumor cell proliferation and vessel density (P < 0.05), creating a more potent therapeutic effect (95% reduction in tumor volume) compared with either hCIK cells or TMZ single therapy (72% for both, P < 0.05). Taken together, CIK cell-immunotherapy and TMZ chemotherapy have synergistic therapeutic effects and could be combined for a successful treatment of GBM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-326.
Abstract LB-332: MDM4 transcription is discordantly regulated by common variants of p53
Authors: Bainer Russell , Marioni John , Barriero Luis , Blekhman Ran , Onel Kenan , Gilad Yoav
Published: February 2011

The transcription factor p53 is a central mediator of the DNA damage response programs controlling cell cycle arrest and apoptosis that are critical to the prevention of oncogenesis. Although p53 has been subject to intense study, the functional consequences of the common proline to arginine coding polymorphism at codon 72 have yet to be fully elucidated. We hypothesized that the previously reported difference in apoptotic potential between cells expressing the two common p53 alleles may be due in part to differences in each variant's ability to transcriptionally regulate downstream target genes. To test this, we used a combination of expression profiling and ChIP-on-chip techniques to identify differences in the transcriptional networks regulated by the alternate alleles of p53 in isogenic cell lines. Our results indicate that although the majority of p53 transcriptional targets are equivalently regulated by both allelic variants, a small number of genes are specifically regulated by the respective versions of p53. Surprisingly, among the genes differentially induced by alternate p53 variants is MDM4 (HDMX), a well-characterized regulator of p53 activity. We subsequently used luciferase expression assays to identify a functional site containing a putative p53 binding element within the MDM4 promoter that discordantly interacts with the two p53 variants. These data provide the first evidence that MDM4 transcription is directly mediated by p53, and suggest a mechanism that could contribute to previously-reported differences in apoptotic potential between the common p53 alleles.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-332.
Abstract LB-333: A CREBZF/Zhangfei isoform activates CHOP and promotes apoptosis during prolonged endoplasmic reticulum stress
Authors: Li Yu , Zhang Yani , Audas Timothy E. , Martyn Amanda C. , Lu Ray
Published: February 2011

The basic leucine zipper transcription factor CREBZF (Zhangfei or ZF) was identified through its interaction with Herpes Simplex Virus-1 related cellular protein HCF-1, and has been implicated in cellular stress responses through its interaction with other proteins, such as CREB3/Luman and ATF4. Here we investigated the production of four CREBZF isoforms, which arise from translational initiation of a downstream AUG at codon 83 and mRNA alternative splicing that adds an IFFFR pentapeptidyl tail to the C-terminus. We found that in addition to transcriptional induction, the short-tailed CREBZF (stZF) isoform was specifically induced by prolonged ER stress treatment and amino acid deprivation. This stZF isoform is a potent transcriptional activator of the pro-apoptotic protein CHOP. Overexpression of stZF activates transcription of CHOP through a CCAAT enhancer binding protein (C/EBP)-ATF site, and promotes apoptosis. We propose that 1) CREBZF is a key component of the integrated stress response; 2) stZF is tightly regulated and induced primarily under prolonged cellular stress, and is essential for the role of CREBZF in inducing CHOP and promoting cell death.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-333.
Abstract LB-336: A novel pathway for CXCR3-B-mediated growth inhibitory signals in renal cancer
Authors: Datta Dipak , Pal Soumitro
Published: February 2011

Chemokines and their receptors are classically known to be involved in tumor cell migration playing a critical role in tumor metastasis. However, their role in regulating direct tumor growth is under appreciated. Although chemokine receptor CXCR3 and their ligands have tumor inhibitory properties, some recent reports suggest that they may also promote tumor growth. We recently reported that this controversy in the function of CXCR3, in terms of tumor inhibition vs. progression, is in part related to the observation that CXCR3 is alternatively spliced producing two variants called CXCR3-A (promoting cell proliferation) and CXCR3-B (mediating growth inhibition). Previously, we observed that the expression of CXCR3-B is markedly downregulated in human renal cancer and overexpression of CXCR3-B in renal tumor cells inhibited endogenous tumor cell proliferation. We hypothesize that CXCR3-B-mediated growth inhibitory signals are one of the crucial factors for the renal cancer cell proliferative response. To dissect the inhibitory signals mediated by CXCR3-B, we first overexpressed CXCR3-B in renal cancer cells (Caki-1 and 786-O) using an overexpression plasmid, and validated the overexpression of CXCR3-B at both mRNA and protein levels by realtime PCR and FACS analysis. As CXCR3-A is known to mediate its proliferative signals through Akt, we first evaluated the status of phospho-Akt in CXCR3-B overexpressed cells compared to control by western blot analysis. We did not find any significant change in the phospho-Akt level in our CXCR3-B overexpressed cells. However, we observed marked cell death (apoptosis) in these CXCR3-B overexpressed cells especially under stress, like serum deprivation. To further understand the anti-proliferative or pro-apoptotic signals through CXCR3-B, we checked the expression pattern of 24 different genes that are related to either cell death or survival by performing a protein array. We found the selective reduction of cytoprotective hemeoxygenase-1 (HO-1) or Heat Shock Protein-32 (HSP-32) gene expression in CXCR3-B overexpressed cells compared with control cells. We also validated the downregulation of HO-1 protein expression by western blot analysis. HO-2 and some important genes directly related to apoptosis (DR4 and DR5) remained unaltered in these CXCR3-B overexpressed cells. Together, HO-1 is known to promote cell survival under stress-induced responses; in this condition, CXCR3-B overexpression may inhibit renal cancer cell proliferation/survival through downregulation of HO-1 expression. Thus, our study defines a novel mechanism of CXCR3-B mediated cell death in human renal cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-336.
Abstract LB-352: B-CLL phenotype in Eµ-miR-29 transgenic mice
Authors: Santanam Urmila , Zanesi Nicola , Efanov Alexey , Palamarchuk Alexey , Costinean Stefan , Hagan John , Croce Carlo , Pekarsky Yuri
Published: February 2011

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in the western world. Human B-CLL occurs in two forms: aggressive (showing high ZAP-70 expression and unmutated IgH VH) and indolent (showing low ZAP-70 expression and mutated IgH VH). We found that miR-29a is upregulated in indolent human B-CLL compared to aggressive B-CLL and normal CD19+ B-cells. To study the role of miR-29 in B-CLL, we generated Eµ-miR-29 transgenic mice overexpressing miR-29 in mouse B-cells. Flow cytometric analysis revealed a markedly expanded CD5+ population in the spleen of these mice starting at 2 months of age. Over 80% of miR-29 transgenic mice exhibited an expanded population of CD5+ B-cells, a characteristic of the B-CLL phenotype. An average of 56% of the B-cell population in these transgenics were CD5 positive. At the age of 2 years these mice showed significantly enlarged spleens and an increase in CD5+ B-cell population of up to 100% of B-cells. Over 8% (3/36) of Eµ-miR-29 transgenic mice developed frank leukemia and prematurely died from the disease at the age of 24-26 months. The expanded CD5+ B-cell population was found to be proliferative, with an increased number of cells in the S-phase of the cell cycle, compared to wild type CD19+ B-cells. These results suggest that deregulation of miR-29 can cause, or at least significantly contribute to the pathogenesis of indolent B-CLL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-352.