bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5331: Interleukin-6 as a therapeutic target in advanced ovarian cancer
Authors: Coward Jermaine , Kulbe Hagen , Leader David , Quigley Mary , Leinster David Andrew , Thompson Richard , Nemeth Jeffrey , Vermeulen Jessica , McNeish Iain , Balkwill Frances R.
Published: February 2011

The inflammatory cytokine IL-6 is a major component of an autocrine cytokine network in human ovarian cancer that influences angiogenesis, a stromal signature and leukocyte infiltration. We have used tissue culture experiments, animal models, and data from a Phase II clinical trial in women with advanced ovarian cancer to investigate the therapeutic potential and mechanisms of action of CNTO328, an antibody that neutralises IL-6. In tissue culture, CNTO328 had no effect on growth or survival of ovarian cancer cells that expressed IL-6 receptors and constitutively secreted the ligand. However, it inhibited constitutive production of IL-6 and other inflammatory cytokines and chemokines, including TNF-alpha, IL-8, IL-1beta and CCL2 by the malignant ovarian cells.

In intraperitoneal ovarian cancer xenograft models, CNTO328 reduced tumour growth and angiogenesis and decreased transcription of inflammatory cytokines in the tumour microenvironment.

Of eighteen patients with advanced, platinum-resistant ovarian cancer treated with CNTO328 in a single arm Phase II trial, there was one partial response, as defined by combined RECIST/CA125 criteria, seven patients experienced periods of disease stabilisation, and in four of these this lasted at least 6 months. Baseline plasma TNF-alpha, IL-8, VEGF, beta2 microglobulin and CRP were significantly lower in patients who had stable disease or partial response. After six weeks therapy, plasma levels of several cytokines were either stable or decreased in patients who had clinical benefit from the anti-IL-6 treatment and TNF-alpha and IL-8 were significantly lower in this group than in those who progressed. Plasma TNF-alpha, IL-8, VEGF and ascites TNF-alpha, IL-8, CCL2 and IL-1beta levels showed a strong decline in the patient with a partial response. We conclude that IL-6 antagonists may have a role to play in the treatment of ovarian cancer. Their actions involve inhibiting production of inflammatory cytokines, chemokines and angiogenic factors that have tumour-promoting actions in the ovarian cancer microenvironment.

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 5331.
Abstract 5334: Mechanism of cysteine-mcMMAF release from the stably linked antibody-drug conjugate SGN-75
Authors: Zhang Xinqun , Okeley Nicole M. , Setter Jocelyn , Law Che-Leung , Benjamin Dennis R. , Senter Peter D. , Alley Stephen C.
Published: February 2011

The antibody-drug conjugate SGN-75 is composed of the humanized monoclonal antibody (mAb) h1F6 and the drug-linker mcMMAF conjugated through interchain disulfide cysteine residues. SGN-75 has been shown to be highly active against tumor cell lines both in vitro and in vivo. The mcMMAF drug-linker was designed to be protected from protease cleavage, and we have shown that cysteine-mcMMAF is the major released drug in vitro. We demonstrate that the cysteine residue in cysteine-mcMMAF comes from the mAb, implying antibody degradation as the mechanism for generation of cysteine-mcMMAF. Two isotope cysteine labeling approaches were utilized in which either total cysteine in tumor cells or the mAb cysteines of h1F6 were labeled with heavy isotope cysteine. Metabolic incorporation of heavy cysteine into CD70-expressing tumor cells or mAb-producing CHO cells using media depleted of cysteine and supplemented with heavy isotope cysteine gave complete labeling by heavy cysteine. Heavy cysteine-labeled cells were treated with unlabeled SGN-75, and unlabeled cells were treated with heavy-cysteine-labeled SGN-75. The results demonstrate that the mAb backbone of SGN-75 is the origin of the cysteine in cysteine-mcMMAF providing evidence that an active drug component can be released from a stably linked ADC through proteolytic degradation of the mAb inside of target cells.

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 5334.
Abstract 5338: Metastatic colorectal cancer cells from patients previously treated with chemotherapy are sensitive to T cell killing mediated by CEA/CD3-bispecific T cell-engaging BiTE antibody
Authors: Osada Takuya , Hsu David , Hammond Scott , Hobeika Amy , Devi Gayathri , Clay Timothy M. , Lyerly H. Kim , Morse Michael A.
Published: February 2011

Carcinoembryonic antigen (CEA; CD66e, CEACAM5) is a well-characterized tumor-associated antigen that is frequently and uniformly over-expressed in human carcinomas. A novel bispecific single-chain antibody of the bispecific T cell engager (BiTE) class named MEDI-565 (also known as MT111) was generated by genetic engineering. MEDI-565 binds CEA on cancer cells and CD3 present on T cells; such binding mediates T cell killing of cancer cells expressing CEA. However, MEDI-565 effectively mediates the killing of cancer cells only if it binds concurrently to CEA on a cancer cell and to CD3 on a T cell.

We hypothesized that metastatic human colorectal cancer (CRC) previously treated with conventional chemotherapy would be sensitive to T cell-mediated killing if T cells of a sufficient magnitude could be activated against the tumor. To test this hypothesis, we selected MEDI-565 to redirect a large number of polyclonal T cells against tumors expressing CEA instead of using a cancer vaccine approach that, in general, is anticipated to elicit few antigen-specific T cells in humans.

We analyzed proliferation and lysis of CEA-positive CRC specimens that had survived prior systemic chemotherapy and biologic therapy to determine if they could be killed by patient T cells engaged by MEDI-565 in vitro. The mechanism of redirected T cell killing was also investigated.

At low concentrations (0.1 to 1 ng/mL), MEDI-565 plus T cells caused reduced proliferation and enhanced apoptosis of CEA-positive human CRC specimens. High levels of soluble CEA (≤ 1,000 ng/mL) did not affect MEDI-565-induced T cell killing of cells expressing CEA, suggesting that endogenous circulating CEA may not impair the clinical activity of MEDI-565 in patients. Cancer cell lines expressing CEA remained sensitive to T cell mediated killing despite repeated exposure to T cells and MEDI-565. These results suggest that MEDI-565/T-cell treatment may not induce escape mechanisms in cancer cells, and, thus, might be suitable for long-term and repeated treatment. Granzyme B and perforin were implicated as potential mediators of MEDI-565-induced T cell killing. Furthermore, MEDI-565 activated T cells to secrete both Tc1 (Th1) and Tc2 (Th2) type cytokines.

This study demonstrates for the first time that metastatic CRC specimens derived from patients previously treated with conventional chemotherapy can be lysed by patient T cells. Clinical testing of cancer immunotherapies such as MEDI-565 that result in exposure of tumors to large numbers of T cells is warranted.

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 5338.
Abstract 5339: Inhibition of breast cancer cell proliferation and unique epitope recognition by EpCAM-specific human monoclonal antibody adecatumumab
Authors: Münz Markus , Murr Alexander , Kvesic Majk , Rau Doris , Mangold Susanne , Pflanz Stefan , Lumsden John , Volkland Jörg , Fagerberg Jan , Riethmüller Gert , Rüttinger Dominik , Kufer Peter , Baeuerle Patrick A. , Raum Tobias
Published: February 2011

Epithelial cell adhesion molecule (EpCAM; CD326) is frequently and highly expressed on a wide variety of human carcinomas. The emerging role of EpCAM as a signalling receptor and activator of the wnt pathway, and its expression on tumor-initiating cells, further add to its attractiveness as target for immunotherapy of cancer.

Thus far, five conventional monoclonal IgG antibodies have been tested in cancer patients for safety and anti-tumor activity. These are murine IgG2a edrecolomab and its murine/human chimeric IgG1 antibody version, and humanized, human-engineered and fully human IgG1 antibodies 3622W94, ING-1, and adecatumumab (MT201), respectively. We have recombinantly produced all antibodies but murine edrecolomab in Chinese hamster ovary cells and investigated all five antibodies for their binding affinity, EpCAM epitope recognition, antibody-dependent cellular (ADCC) and complement-dependent cytotoxicity (CDC), and inhibition of breast cancer cell proliferation.

ING-1 and 3622W94 bound to recombinant EpCAM with much higher affinity than adecatumumab and edrecolomab, which was largely determined by slower off-rates. Edrecolomab, ING-1, and 3622W94 all recognized epitopes in the exon 2-encoded, N-terminal domain of EpCAM, while adecatumumab recognized a more membrane proximal epitope encoded by exon 5. All antibodies induced lysis of EpCAM-expressing human cancer cell lines by both ADCC and CDC with potencies that correlated with their binding affinities for recombinant EpCAM. The chimeric version of edrecolomab with a human Fcγ1 domain was much more potent in ADCC with human effector cells than the murine IgG2a version of the antibody. Of the five antibodies, only adecatumumab showed a significant inhibition of MCF7 breast cancer cell proliferation in the absence of complement and immune cells.

A moderate binding affinity and recognition of a distinct domain of EpCAM may best explain why adecatumumab showed a larger therapeutic window in cancer patients than the two high-affinity IgG1 antibodies ING-1 and 3622W94, both of which caused acute pancreatitis. Adecatumumab emerges as an anti-EpCAM antibody with unique characteristics and biological activity.

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 5339.
Abstract 534: Invasive human prostate cancer and integrin cleavage: Potential role of uPAR contributed by macrophages
Authors: Cress Anne E. , Sandoval Cynthia P. , Gard Jaime M.C. , Pawar Sangita C. , Sroka Isis C. , Abril Edward R. , Nagle Raymond B.
Published: February 2011

Laminin binding integrins are major determinants of cancer cell migration, invasion and metastasis. Our previous work showed that integrin α6β1 is cleaved on the tumor cell surface by urokinase-type plasminogen activator (uPA), producing a structural variant, α6pβ1. Urokinase plasminogen activator receptor (uPAR) is a regulatory determinant for α6 integrin cleavage since uPAR interacts with integrin and activates uPA. Previous work by others has shown that both human tumor tissue and tumor infiltrating macrophages express uPAR . In the present study, we investigated the potential of uPAR to co-localize with α6β1 integrin in human prostate cancer cells (DU-145) and whether uPAR expressed on the macrophage cell surface mediates integrin α6β1 cleavage. The results indicated uPAR and integrin α6β1 were co-expressed in invasive human prostate carcinoma. Co-localization of uPAR and integrin α6β1 occurred in some tumor cells in vitro, consistent with reports indicating a variable distribution in human tumors. The culture of macrophages with tumor cells resulted in an increased cleavage of integrin α6 as detected by immuno precipitation followed by western blot analysis. Taken together, these data suggest that integrin α6 cleavage is directed by the receptor for uPA, uPAR, contributed either by the tumor cell itself or tumor cell contact with macrophages. (Supported in part by CA 56666, CA23752, T34 GM008718 and the TACMASS core service of the Arizona Cancer Center)

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 534.
Abstract 5340: Impact of binding epitope and antigen size on the cytotoxic activity of MCSP-specific BiTE antibodies for treatment of melanoma
Authors: Bluemel Claudia , Hausmann Susanne , Fluhr Petra , Sriskandaradja Mirna , Baeuerle Patrick , Kufer Peter
Published: February 2011

Melanoma chondroitin sulphate proteoglycan (MCSP; also called CSPG4, HMW-MAA, MSK16, MCSPG, MEL-CSPG, NG2, or gp240) is a surface antigen frequently expressed on human melanoma cells, which is involved in cell adhesion, invasion and spreading, angiogenesis, complement inhibition, and signalling. MCSP has therefore been frequently selected as target antigen for development of antibody- and vaccine-based therapeutic approaches. We have here used a large panel of monoclonal antibodies against human MCSP for generation of single-chain MCSP/CD3-bispecific antibodies of the BiTE (for bispecific T cell engager) class.

BiTE antibodies can transiently connect the T cell receptor subunit CD3 on T cells with a surface antigen on target cells leading to a highly efficient redirected lysis of target cells. This involves cytolytic synapse formation and delivery of perforin and granzymes. BiTE-engaged T cells are capable of serial target cell lysis, and are not affected by immune escape mechanisms interfering with peptide antigen processing and presentation, or clonal T cell differentiation.

Despite similar binding affinity to MCSP, respective BiTE antibodies greatly differed in their potency of redirected lysis of CHO target cells stably transfected with full-length human MCSP, MCSP deletion mutants or fusion proteins. BiTE antibodies binding to the membrane proximal domain D3 of MCSP were more potent than those binding to more distal domains. This epitope distance effect was corroborated with EpCAM/CD3-bispecific BiTE antibody MT110 by using MCSP/EpCAM fusion proteins as surface target antigens. Generally, CHO cells expressing small surface antigens were better lysed than those with large antigens, indicating that antigen size is also an important factor for BiTE potency. This is in line with the observation that target cell lysis by membrane proximally-binding BiTE antibodies improved upon omission of more distal MCSP domains.

The present study for the first time relates the size of surface antigens and positioning of binding domains to BiTE potency of target cell lysis via redirected cytotoxic T cells. In case of the MCSP antigen, this provides the basis for selection of a maximally potent BiTE antibody candidate for development of a novel melanoma therapy.

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 5340.
Abstract 5343: Development of novel anti-CD27 human antibodies with therapeutic potential
Authors: He Li-Zhen , Vitale Laura , O'Neill Tom , Crocker Andrea , Widger Jenifer , Storey Jim , Weidlick Jeff , Zhang Yan , Marsh Henry , Keler Tibor
Published: February 2011

The costimulatory molecule CD27 is a member of the tumor necrosis factor (TNF) receptor superfamily, and is constitutively expressed on the majority of mature T cells, memory B cells, and a portion of NK cells. The interaction of CD27 with its ligand CD70 plays key roles in T cell activation, proliferation, survival, maturation of effector capacity and memory; in clonal B cell expansion and germinal center formation; and in NK cell cytolytic activity. Previous reports have shown that antigen-specific CD8+ cytolytic T cell immunity can be augmented through CD27 activation in mice. Of particular relevance is the work by M. J. Glennie et al. demonstrating that an agonistic anti-mouse CD27 mAb given without a DC maturation signal has potent anti-tumor activity through boosting of T cell immunity. To explore the therapeutic potential of this target, a panel of fully human antibodies recognizing human CD27 was generated using human Ig transgenic mice immunized with recombinant human CD27. These human anti-CD27 mAbs showed specific and high affinity binding to CD27 and CD27-expressing lymphoma cells. We generated transgenic mice that express human CD27 (hCD27-Tg) to evaluate the anti-human CD27 mAbs in vivo. The expression profile and regulation of the human CD27 transgene driven by its own promoter were similar to that observed with endogenous mouse CD27. Administration of anti-human CD27 mAbs in combination with ovalbumin greatly enhanced antigen specific T cell responses compared to ovalbumin plus human IgG1 isotype control in the hCD27-Tg mice. The SIINFEKL-specific CD8+ T cell proliferation and activation were detected by pentamer staining and IFNγ ELISPOT analysis. These data support the further development of these novel human anti-CD27 antibodies and we are currently investigating their therapeutic activity using various in vivo tumor models.

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 5343.
Abstract 5347: Disruption of PDZ protein-protein interactions inhibits Tax transformation and HTLV-1 infection capacities
Authors: Twizere Jean-Claude , Dewulf Jean-François , Legros Sebastien , Boxus Mathieu , Zimmermann Pascale , Fujii Naoaki , Kettmann Richard
Published: February 2011

Approximately 15 to 25 million people worldwide are infected with human T-cell leukaemia virus type 1 (HTLV-1) or type 2 (HTLV-2). One of the viral regulatory proteins, Tax, is critical for viral transcription and replication and has been clearly implicated in T-lymphocyte transformation in vitro and oncogenesis in vivo. Elucidation of the metabolic processes involved in Tax activity is thus of prime importance for understanding the pathogenesis induce by HTLV.

Interactions between Tax and a selected group of PDZ containing proteins are associated with the transforming activities of Tax1 as well as persistent HTLV-1 infection. We demonstrate that the PDZ-containing protein syntenin-1 and −2, known to interact with Heparan sulfate proteoglycan receptor syndecan-1 and to connect cytoskeletal proteins, interact with HTLV-1 Tax and with the HTLV-1 receptor GLUT-1 but not with HTLV-2 Tax. Both PDZ1 and 2 domains of syntenins are required for Tax binding. We also show that syntenin-2 co-localizes with Tax in nuclear speckles. Furthermore, we demonstrate that an antagonist for PDZ protein- protein interaction suppresses Tax-induced transformation and prevents T cell infection by HTLV-1. Thus, disruption of PDZ protein-protein interaction may provide new therapeutic opportunities for HTLV-1 induced diseases.

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 5347.
Abstract 5349: Vesicular stomatitis virus oncolysis is potentiated by impairing mTORC1-dependent type-I IFN production
Authors: Alain Tommy , Lun XueQing , Martineau Yvan , Sean Polen , Pulendran Bali , Petroulakis Emmanuel , Zemp Franz , Lemay Chantal G. , Roy Dominic , Bell John C. , Thomas George , Kozma Sara C. , Forsyth Peter A. , Costa-Mattioli Mauro , Sonenberg Nahum
Published: February 2011

Oncolytic viruses constitute a promising therapy against malignant gliomas (MGs). However, virus-induced type-I interferon (IFN) greatly limits its clinical application. The kinase mTOR (mammalian target of rapamycin) stimulates type-I IFN production via phosphorylation of its effector proteins, 4E-BPs and S6Ks. Here we show that both mouse embryonic fibroblasts (MEFs) and mice lacking S6K1 and S6K2, are susceptible to Vesicular Stomatitis Virus (VSV) infection due to an impaired type-I interferon response. We used this knowledge to employ a pharmacoviral approach to treat MGs. The highly specific inhibitor of mTOR, rapamycin, in combination with an IFN-sensitive VSV-mutant strain (VSVΔM51), dramatically increased the survival of immunocompetent rats bearing MGs. More importantly, VSVΔM51 selectively killed tumor, but not normal cells, in MG-bearing rats, which were treated with rapamycin. These results demonstrate that reducing type-I IFNs through inhibition of mTOR is an effective strategy to augment the therapeutic activity of VSVΔM51.

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 5349.
Abstract 535: Development of small-molecule hepsin inhibitors
Authors: Tang Xi , Vasioukhin Valeri
Published: February 2011

Hepsin is a cell-surface serine protease prominently overexpressed in the majority of human prostate tumors. We and others have previously demonstrated that hepsin promotes prostate cancer progression and metastasis in vivo. These findings identified hepsin as a very attractive therapeutic target in prostate cancer. To develop small molecule hepsin inhibitors, we have previously performed in vitro screenings of libraries of small drug-like molecules. These efforts resulted in identification of several lead compounds inhibiting hepsin proteolytic activity. We now identified and performed additional characterization of the derivatives of most potent hepsin lead inhibitors. We also developed a novel cell-based hepsin activity assay, which utilizes expressed on the cell-surface human hepsin and C-terminally HA-tagged pro-HGF, as its specific cleavage substrate. Overall, this study identified specific and potent small-molecule hepsin inhibitors that may be potentially used in the future as therapeutic agents to attenuate prostate cancer progression in the ‘watchful waiting’ cohort of prostate cancer 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 535.
Abstract 5350: Does hepatitis C virus core protein promote liver cancer through androgen-receptor mediated signaling?
Authors: Ray Ratna B. , Steele Robert
Published: February 2011

Hepatitis C virus (HCV) infection is frequently associated with the development of hepatocellular carcinoma (HCC), which is one of the male dominant diseases. Androgen signaling in liver may be related to carcinogenesis. In this study, we investigated whether HCV proteins cross-talk with androgen receptor (AR) signaling pathway for promotion of liver cancer. We have demonstrated that HCV core protein alone or in context with other HCV proteins enhances AR-mediated transcriptional activity, and further augments in the presence of androgen. Subsequent study suggested that HCV core protein activates STAT3, which in turn enhances AR-mediated transcription. This activity was blocked by a pharmacological inhibitor of Jak/Stat signaling pathway, AG490. Vascular endothelial growth factor (VEGF) is a target gene of androgen receptor in liver, and plays an important role in angiogenesis. Therefore, we examined whether HCV infection modulates VEGF expression in hepatocytes. Our results demonstrated that HCV enhances VEGF expression and facilitates tube formation in human coronary microvascular endothelial cells in the presence of AR. We are in the process of evaluating the AR targets in the hepatocytes following HCV infection.

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 5350.
Abstract 5353: Identification of a subset of AIDS related lymphoma (ARL) containing HIV infected macrophages that is immunophenotypically distinct from EBV+ ARL
Authors: Huysentruyt Leanne C. , Bracci Paige M. , McGrath Michael S.
Published: February 2011

The risk of developing non-Hodgkin lymphoma is 60X greater in the HIV-infected population when compared to non-infected individuals despite the initiation of highly active antiretroviral therapy (HAART). The primary difference between lymphoma in non-infected individuals and those with AIDS related lymphoma (ARL) is that ARL is high-grade and metastatic. Since the introduction of HAART the incidence of ARL has decreased but not the same extent as other AIDS-related malignancies and there has been little change amongst the CD4 strata. Therefore, with the increase in life expectancy afforded by HAART, the overall number of ARL cases is expected to rise in the future. Preliminary reports have suggested that some ARLs contain HIV-infected macrophages that may contribute to ARL pathogenesis. A recent study evaluating HIV sequence evolution in the contest of metastatic ARL found lymphoma specific HIV compartmentalized within sites of lymphoma that was distinct from HIV present in non-lymphoma sites (Salemi et al, PLOSone Dec 3, 2009). These data suggested the existence of a lymphoma specific form of HIV evolving within individuals who develop ARL. The goal of this research was to determine the incidence of HIV infected lymphomas in the pre and post-HAART eras and if HIV-positive lymphomas have a specific immunophenotype. A tissue microarray containing ∼150 of ARLs (from 1982-2007) was obtained through the AIDS and Cancer Specimen Resource (ACSR) and was used for HIV p24 and macrophage CD68 immunohistochemistry. Double staining techniques confirmed that p24 expression was localized to tumor associated macrophages (TAM). There was a highly significant (p<0.001) increase in the frequency of p24+ ARL cases post-HAART (after 1996; 49%) as compared to pre-HAART (before 1996; 26%). Using antigen expression data CD20, CD3, CD10, BCL6, BCL2, MUM1, Ki67, blimp, p53 and EBV, provided by the ACSR, we were able to determine that p24+ ARLs were generally of B cell origin but did not have a specific immunophenotype. In contrast, EBV+ ARLs were more likely to express MUM1 or blimp and less likely to express CD29, CD10 or BCL6. EBV status was not associated with a pre/post HAART diagnosis (44 vs. 40%). However, a subset of EBV-/p24+ tumors was identified. In the pre-HAART era, 13% of the tumors were EBV-/p24+ compared to 30% in the post-HAART era suggesting, that the incidence of this tumor type is increasing (p<0.05). These data describe for the first time the existence of potentially tumor specific HIV in up to 1/3 of all post HAART ARLs, a class of tumor that is immunophenotypically distinct from EBV+ ARLs.

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 5353.
Abstract 5355: HPV-16 infection alters cellular microRNA expression in squamous cell carcinoma of the head and neck (SCCHN)
Authors: Wald Abigail I. , Wells Susanne I. , Ferris Robert L. , Khan Saleem A.
Published: February 2011

Up to 30% of squamous cell carcinoma of the head and neck (SCCHN) contain human papillomavirus (HPV) type 16 DNA. The presence of HPV DNA in these cancers is associated with a better disease outcome, and an understanding of the differences between HPV-positive and HPV-negative SCCHN has significant clinical importance. MicroRNAs (miRNAs) are approximately 22 nucleotides long, single-stranded RNAs that regulate gene expression at a posttranscriptional level. We hypothesize that HPV infection alters cellular miRNA expression which leads to changes in the expression of their target genes. We investigated the expression of cellular miRNAs using microarrays and quantitative Real Time RT-PCR. We found that 3 miRNAs were upregulated and 8 miRNAs were downregulated in HPV-positive SCCHN cell lines compared to HPV-negative SCCHN cell lines. MiR-363, miR-497, and miR-33 were upregulated, while miR-155, miR-181a, miR-181b, miR-29a, miR-218, miR-222, miR-221, and miR-142-5p were downregulated. We also analyzed miRNA expression in HPV-positive and HPV-negative SCCHN tumors and normal oral tissues. There were 17 up- and 1 downregulated miRNAs in SCCHN tumors compared to normal oral mucosa. These included several miRNAs that are known to be altered in many cancers, such as miR-21, miR-17-5p, and miR-145. MiR-363, the most upregulated miRNA in the HPV-positive cell lines, was also upregulated in HPV-positive tumors compared to HPV-negative tumors. Preliminary data using cell lines expressing HPV-16 E6 and/or E7 oncogene has shown that miR-363 expression increases with the expression of E6. These results suggest a possible role of HPV in altering the expression of specific cellular miRNAs, including miR-363. Studies are currently in progress to identify miR-363 gene targets by utilizing gene expression data and spectral counting proteomics. MiRNAs altered by the presence of HPV may identify specific pathways targeted by the virus, and may provide novel therapeutic targets for HPV-associated SCCHN.

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 5355.
Abstract 5356: Inactivation of Foxo3a and increased expression of Id1 by the Epstein-Barr Virus-encoded LMP1 facilitates resistance to TGF-β-mediated growth inhibition in nasopharyngeal epithelial cells
Authors: Lo Angela KF , Dawson Christopher W. , Young Lawrence S.
Published: February 2011

The universal association of Nasopharyngeal carcinoma (NPC) with EBV underscores the importance of EBV infection to the development of this disease. The EBV-encoded Latent Membrane Protein-1 (LMP1) is believed to be a key factor in NPC development due to its ability to induce cellular transformation in various cell types. As a viral mimic of CD40, LMP1 functions as a constitutively active TNF receptor, altering multiple signal cascades and activating a plethora of downstream targets. LMP1 has been shown to inactivate the transcriptional activity of Foxo3a, a tumor suppressor that can inhibit the proliferation of tumor cells. LMP1 has also been found to increase expression of Id1, a transcriptional repressor that can inhibit the expression of differentiation-linked genes. Here, we report that inactivation of Foxo3a by LMP1 facilitates Id1 induction. Using a panel of LMP1 mutants, we identified the CTAR1 domain of LMP1 as being responsible for Foxo3a inactivation and Id1 upregulation.

Through the use of dominant negative proteins, shRNA silencing or selective pharmacological inhibitors, we demonstrate that Foxo3a inactivation by LMP1 is mediated through the LMP1 CTAR1 domain and requires activation of the Akt and Erk-MAPK signaling pathways. Whilst engagement of the Akt, Erk-MAPK and NIK-dependent noncanonical NF-κB pathways by LMP1 are involved in Id1 upregulation, we found that LMP1 CTAR2 domain-mediated IKKβ-dependent canonical NF-κB signaling negatively regulates Id1 expression, suggesting that CTAR2 may antagonize CTAR1-mediated regulation of Id1. LMP1 has been shown to inhibit TGFβ-mediated growth inhibition by disrupting various facets of TGFβ signaling. Here we show that stable “knock-down” of Id1 in LMP1 expressing NP69 cells after stable expression of Id1-specific shRNA, reduced the growth inhibitory effect of TGFβ. The interplay between LMP1, Foxo3a and Id1 is likely to contribute to the characteristic resistance of LMP1 to TGFβ-mediated signaling and cell growth arrest. The data presented in this study may offer a novel therapeutic approach for EBV associated epithelial cancers.

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 5356.
Abstract 5358: Epstein-Barr Virus-encoded BARF1 gene stimulates gastric epithelial cell MMP-1 secretion through ERK activation
Authors: Jeong Jin-Yong , Byun Hyun-Jeong , Woo Jun Hee , Kim Chul Woo , Kim Woo Ho , Chang Mee Soo
Published: February 2011

The Epstein-Barr virus (EBV), originally isolated from Burkitt's lymphoma tissue, has now been associated with various epithelioid diseases and many other malignancies, including gastric adenocarcinoma. Our interest has been focused on the BARF1 early gene from EBV, which has ability to induce oncogenic transformation in rodent fibroblasts and to immortalize monkey kidney primary epitherial cells. The aim of this study was to investigate the effect of BARF1 expression in gastric cancer cells. First, a pEGFP vector containing the full length BARF1 gene was constructed and transfected into EBV negative gastric cancer cell lines (AGS and SNU601). Microarray analysis was then performed and gene expression profiles were analyzed and compared between the cell containing full length BARF1 gene and the vector control. We found that matrix metalloproteinase-1 (MMP-1) was significantly up-regulated in the cell containing BARF1 gene. The MMP-1 mRNA and protein expression levels are confirmed by RT-PCR and Western blotting. Additionally, the mobility of BARF1 transfectants was increased in scrape-wound migration assay compared with the vector control cells. Because MMP-1 secretion in other cell types is extracellular signal regulated kinase (ERK)-dependent, we examined mitogen-activated protein kinase (MAPK) ERK activation in response to BARF1. BARF1 also induced activation of ERK. To determine whether BARF1-induced MMP-1 secretion was ERK-dependent, we used PD98059 and UO126, the specific inhibitors of MEK, the proximal activator of ERK. UO126 and PD98059 inhibited ERK activation and MMP-1 secretion, indicating that MMP-1 secretion in response to BARF1 was MEK- and ERK-dependent. Because p38 activity mediates MMP-1 secretion in dermal fibroblasts and several other cell types, but inhibits MMP-1 secretion in cytokine-stimulated AGS cells, we also examined the effects of p38 inhibition on MMP-1 secretion in response to BARF1. p38 inhibition with the specific p38 inhibitors, SB203580 and SB202190, enhanced MMP-1 secretion, as well as ERK activation. These results indicate that EBV-encoded BARF1 gene stimulates gastric epithelial cell MMP-1 secretion via ERK activation. This is the first report that a viral protein, BARF1, is capable of regulating MMP-1.

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 5358.
Abstract 536: Mesenchymal stromal cells promote tumor growth both in vitro and in vivo
Authors: Suzuki Kazuhiro , Origuchi Makoto , Kanehira Masahiko , Sun Ruowen , Takahata Takenori , Itoh Jugoh , Fukuda Shinsaku , Umezawa Akihiro , Saijo Yasuo
Published: February 2011

[Background] Mesenchymal stromal cells (MSCs), also referred as mesenchymal stem cells are pluripotent progenitor cells that differentiate into chondrocytes, adipocytes, osteoblasts and other types of cell. Although MSCs are resident mainly in bone marrow, MSCs are found in adipose tissue, lung, and many other organs where MSCs maintain and regenerate the connective tissues of organs. Recent report proposed that MSCs also migrate and function as stromal cells in the tumor tissues. Effects of MSCs on tumor growth in vitro and in vivo are still unclear. In this study, we verified tumor promotion by MSCs and analyzed mechanisms. [Method] B16-LacZ, a melanoma cell line expressing β-galactosidase protein, was tested for their growth rate by X-gal colorizing assay in the presence or absence of mouse bone marrow MSCs in vitro. Growth of B16-LacZ was also examined in the detached condition using cell disk or conditioned medium from MSCs. Next, B16-LacZ and Lewis Lung Carcinoma (LLC) cells were mixed with MSCs at 1/1 and 1/5 ratios and subcutaneously inoculated into mice. Tumor sizes were measured and immunostaining of CD31 was performed to evaluate angiogenesis. We also determine the secretion of soluble factors associated with angiogenesis in cultured medium from B16-LacZ alone, MSCs alone, or B16-LacZ and MSCs ELISA. [Result] Proliferation of B16-LacZ co-cultured with MSCs exhibited 5.8 times greater than that of B16-LacZ alone in vitro (P<0.01). In detached condition, using cell disk or conditioned medium from MSCs, the growth rate was only 1.6 times (P<0.01) in cell disk, and 1.4 times (P<0.05) in conditioned medium at 60-hour incubation. Mixed group of B16-LacZ and MSCs at 1/1 and 1/5 ratios developed 2.3 times (P<0.05) and 4.3 times (P<0.01) grater tumor compared to B16-LacZ alone in vivo. MSCs alone did not develop a tumor. Results of LLC experiments were similar to B16-LacZ experiments. Tumor vessel area of mixture of B16-LacZ and MSCs was 2.4 times (P<0.05) at 1/1 and 4.2 times (P<0.01) at 1/5 ratio lager than B16-LacZ alone. The amount of the secretion of LIF, M-CSF, MIP-2 and VEGF factors from MSCs were significantly larger compared with B16-LacZ. The amount of the secretion from co-culture of B16-LacZ and MSCs was almost the same as the MSCs alone group. [Conclusion] MSCs promoted tumor growth both in vitro and in vivo, and promotion of tumor growth by MSCs can be at least in part attributed to the tumor angiogenesis.

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 536.
Abstract 5363: HER-2 over-expression in a subset of soley estrogen-induced breast tumors in intact female ACI rat
Authors: Li Sara Antonia , Hong Yan , Li Jonathan J.
Published: February 2011

Breast cancer comprises about 30% of all cancers occurring in USA women. Gene profiling expression data of human breast cancer have characterized luminal A and B subtypes, comprising 73% of all breast cancers in women, as exhibiting both estrogen receptor alpha (ERα) and progesterone receptor (PR) positivity, as well as over-expression of FOX-A1 and GATA-3 transcription factors, and primarily p53wt. It is well established that 25-30% of these human breast cancers exhibit amplification of the gene or over-expression of the protein product of human epidermal growth factor receptor-2 [HER-2/neu, also known as epidermal growth factor receptor 2 (ErbB-2)], a tyrosine kinase transmembrane receptor involved in signal transduction pathways leading to cell growth and differentiation, and playing a crucial role in the acceleration and evolution of cancer. In breast cancer, its over-expression is associated with poor prognosis and increased metastatic potential. We have shown that the intact female ACI rat breast tumor model induced by estrogen remarkably recapitulates the aforementioned luminal A/B subtypes of human breast cancer, both in its histopathological progression and molecular alterations. In addition, this estrogen-induced mammary tumor is characterized by c-myc amplification, cyclin E1, MDM2, and Aurora A/B mitotic kinase over-expression, centrosome over-duplication, chromosomal instability, and aneuploidy; the defining feature of human breast cancer. Employing western blot analyses, we now report that 29% of 17β-estradiol-induced primary ACI rat breast tumors exhibited pronounced levels of HER-2/neu expression. Immunohistochemical analyses revealed that the HER-2/neu over-expression was confined to pre-invasive lesions, cribiform and comedo ductal carcinomas in-situ (DCIS), and primary invasive tumors, suggesting that estrogen is in some manner involved in initiating its over-expression in a subset of these breast tumors. However, the large majority of estrogen-elicited mammary tumors in ACI rats were essentially devoid of HER-2/neu expression. [Supported by the Susan G. Komen for the Cure Grants BCTR42906 and BCTR0600996].

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 5363.
Abstract 5369: AN019 in combination with ionizing radiation retards intracranial tumor growth and inhibits angiogenic induction in vitro and in vivo
Authors: Gondi Christopher S. , Gorantla Bharathi , Rao A.K.S. Bhujanga , Amala K. , Naidu M.U.R. , Jogi K.V. , Ramana G.V. , Chowdary M. Praveen , Rao Jasti S.
Published: February 2011

Successful treatment of malignant glioma is hampered by the development of resistance to alkylating agents such as Temozolomide (TMZ). The addition of radiation to a TMZ treatment regime has shown promising results with reported survivability of up to 5 years. One of the side effects of Temozolomide is the increased activation of angiogenic factors which may work contrary to the desired result. In this report we demonstrate the development of a novel compound AN019, showing specific VEGF suppression accompanied with anti-angiogenic and anti-proliferative properties in gliomas. We used U87, a glioma cell line, and EGFRvIII over-expressing glioma xenograft 4910 cells for this study. Deduced IC50 values indicated that AN019 had greater anti-proliferative effect than Temozolomide (U87: AN019=103µM, TMZ=768µM; 4910: AN019=169µM, TMZ=582µM). Matrigel invasion assay indicated that AN019 retarded the invasive potential of both U87 and 4910 glioma cells over TMZ treated cells which was enhanced after radiation treatment. In-vitro angiogenic and migration assays showed an almost complete inhibition of angiogenic induction and migration in U87 and 4910 cells after AN019 treatment when compared to TMZ. Cell cycle analysis revealed that 100µg/ml concentration of AN019 was sufficient to achieve >70% apoptosis in both U87 and 4910 cells, whereas 150µg/ml of TMZ was required to achieve the same response. Western blot and ELISA for the expression of VEGF levels indicated that lower concentrations of AN019 (U87=86±3µg/ml and 12±1µg/ml with radiation; 4910=100±1µg/ml and 6µg/ml with radiation) were required for 50% inhibition of VEGF expression. TMZ treatment required a higher concentration to achieve similar 50% inhibition of VEGF expression (U87=80±10µg/ml and 12±3µg/ml with radiation; 4910=100±3µg/ml and 27±3µg/ml with radiation). Animal studies showed that oral doses of AN019 (20mg/kg) regressed tumors in all animals and 70% of the animals showed complete absence of intracranial tumors, whereas TMZ (100mg/kg) treated animals also showed regression of tumors with a 30% cure rate. Overall, our results demonstrate that AN019 has anti-angiogenic, anti-proliferative and anti-tumorogenic properties which may have clinical implications.

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 5369.
Abstract 5372: Mechanisms of synergy of histone deacetylase inhibitors, belinostat and depsipeptide, with DNA damaging agents, etoposide and cisplatin in small cell lung cancer cell lines
Authors: Luchenko Victoria , Salcido Crystal D. , Zhang Yongwei W. , Mumau Melanie D. , Agama Kelli , Giaccone Giuseppe , Pommier Yves , Bates Susan E. , Varticovski Lyuba
Published: February 2011

Small cell lung cancer (SCLC) is the most aggressive type of lung carcinoma. SCLC has a high response rate to chemotherapy, but rapid onset of drug resistance. Chemotherapeutic treatment using combinations of drugs that target different signaling pathways improves overall survival of patients with SCLC. Histone deacetylase (HDAC) inhibitors regulate epigenetic changes and play a role in regulating cell cycle progression and have been suggested as potential therapeutic agents for SCLC. HDAC inhibition is thought to relax DNA, thereby allowing increased access of transcription factors to certain promoters. Likewise, they could increase accessibility of DNA to cytotoxic agents. We examined whether two distinct HDAC inhibitors, belinostat and depsipeptide, have an effect on SCLC cell lines and whether they could be combined with conventional agents used for SCLC, VP16 (etoposide) and cisplatin. We used simultaneous and schedule-dependent treatment protocols of SCLC cells with single drugs and drug combinations. Computational analysis of cell survival using combination index (CI) showed that HDAC inhibitors synergized with DNA damaging agents when administered simultaneously, but this effect was only additive if cells were pre-treated with HDAC inhibitors for 24 hours prior to DNA damaging agents. In addition, using DNA damaging agents 24 hours prior to HDAC inhibitors was clearly antagonistic with CI >1 for all drugs and cell lines tested. Because of a potential use of belinostat and depsipeptide for therapy of SCLC in combination with conventional chemotherapies, we examined the mechanisms of synergy and protection between these agents. We found that PARP degradation was complete when drugs were used simultaneously, but was decreased if HDAC inhibitors were used prior to cisplatin or etoposide. Similar effects were observed by analysis of cell cycle and γH2AX phosphorylation. Thus, schedule of drug administration will be critical for development of clinical protocols for therapy of SCLC using these agents.

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 5372.