bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract PR10: High angiogenic capacity of inflammatory neutrophils and polarized M2 macrophages is determined by production of MMP-9 unencumbered by its natural inhibitor TIMP-1
Authors: Zajac Ewa , Schweighofer Bernhard , Casar Berta , Kupriyanova Tatyana , Rimann Ivo , Juncker-Jensen Anna , Deryugina Elena , Quigley James P.
Published: August 2014

By delivering a potent matrix metalloproteinase, MMP-9, inflammatory neutrophils and macrophages play an important role in tumor angiogenesis. We have previously demonstrated that high angiogenic capacity of neutrophil MMP-9 (nMMP-9) is determined by its TIMP1-free status. In this study, we compared biochemically and functionally nMMP-9 with the MMP-9 produced by monocytes and macrophages of innate (M0), tumor-suppressing (M1) and tumor-promoting (M2) phenotypes. The angiogenic potential of a specific leukocyte type correlated with amount of TIMP-1 complexed with secreted proMMP-9. Similar to neutrophils, M2-macrophages produce proMMP-9 complexed with very low amounts of TIMP-1, rendering its high angiogenic capacity. In contrast, M0 macrophages and M1-polarized macrophages secrete non-angiogenic proMMP-9 complexed with TIMP-1 at near stoichiometric ratios. However, silencing of TIMP-1 in M0- and M1-macrophages results in induction of their angiogenic potential, thereby supporting a biochemical mechanism for unique angiogenic capacity of proMMP-9 delivered by neutrophils and a distinct subset of pro-tumorigenic macrophages.

This abstract is also presented as Poster B89.

Citation Format: Ewa Zajac, Bernhard Schweighofer, Berta Casar, Tatyana Kupriyanova, Ivo Rimann, Anna Juncker-Jensen, Elena Deryugina, James P. Quigley. High angiogenic capacity of inflammatory neutrophils and polarized M2 macrophages is determined by production of MMP-9 unencumbered by its natural inhibitor TIMP-1. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr PR10.
Abstract PR3: The cholesterol metabolite 27-hydroxycholesterol increases breast cancer tumor growth and metastasis
Authors: Nelson Erik Russell , Wardell Suzanne E. , Howe Matthew K. , Carver Nicole J. , Umetani Michihisa , McDonnell Donald P.
Published: August 2014

Breast cancer remains the most common cancer and is the second leading cause of cancer death in women. The magnitude of this problem provides strong rationale for studies that may lead to the development of new chemopreventative strategies and/or lifestyle changes that reduce cancer incidence. It is of significance, therefore, that circulating cholesterol has been correlated to the development of breast cancer, and patients taking lipophilic inhibitors of 2-hydroxy-3-methylglutaryl coenzyme A (statins) demonstrate significantly lower breast cancer incidence, and decreased breast cancer recurrence. Therefore, our recent finding that 27-Hydroxycholesterol (27HC), a primary metabolite of cholesterol, exerts partial agonist activity on both the estrogen receptors (ERs) and liver X receptors (LXRs) suggests a potential, mechanistic link between hypercholesterolemia and breast cancer incidence. Importantly, the enzyme responsible for the conversion of cholesterol to 27HC (CYP27A1) is primarily expressed in macrophages, and it is well established that tumor infiltrating macrophages are associated with more aggressive tumors and worse patient outcome. Therefore, we initiated a series of studies to determine the impact of 27HC on breast cancer pathophysiology. Here, we demonstrate that (1) macrophage produced 27HC increases breast cancer cell proliferation, (2) elevation of exogenous 27HC increases in vivo tumor growth and lung metastases, and (3) genetic ablation of the enzyme responsible for 27HC synthesis increases latency, and reduces tumor growth and metastasis. Our ongoing work is aimed at identifying the mechanisms responsible for the 27HC induced increase in metastasis. In summary, our data thus far strongly indicate a role for macrophage produced 27HC in breast cancer pathophysiology and metastasis. The results provide additional support for the exploration of potential chemopreventative benefits of lower cholesterol diets, pharmacological inhibitors of HMG-CoA reductase or CYP27A1, and macrophage ablative strategies.

DOD Postdoctoral Award BC085585 (ERN), NIH 5R37DK048807 (DPM).

This abstract is also presented as Poster B50.

Citation Format: Erik Russell Nelson, Suzanne E. Wardell, Matthew K. Howe, Nicole J. Carver, Michihisa Umetani, Donald P. McDonnell. The cholesterol metabolite 27-hydroxycholesterol increases breast cancer tumor growth and metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr PR3.
Abstract A21: Active immunotherapy with PROSTVAC® demonstrates potent antitumor efficacy in a mouse model of prostate cancer.
Authors: Rountree Ryan B. , Mandl Stefanie J. , Cote Joseph , Cruz Tracy dela , Giffon Thierry , Gordon Evan , Foy Susan P. , Lombardo John R. , Trent Erica , Laus Reiner , Delcayre Alain
Published: August 2014

BN ImmunoTherapeutics (BNIT) specializes in developing novel active immunotherapies for cancer. These therapies use recombinant poxviruses engineered to express tumor-associated antigens (TAAs), with the intent of generating effective immune responses against the patients' cancer. PROSTVAC® is a candidate product for the treatment of prostate cancer for which a global Phase III clinical trial (PROSPECT) was recently initiated. This product is composed of two different viral vectors derived from a recombinant vaccinia virus (PROSTVAC™-V) and a recombinant fowlpox virus (PROSTVAC™-F). Both vectors contain transgenes encoding prostate-specific antigen (PSA) and a triad of costimulatory molecules (B7-1, ICAM-1, and LFA-3), designated as TRICOM™. Patients are immunized using a prime-boost strategy consisting of an initial treatment with PROSTVAC™-V followed by repeated boosting with PROSTVAC™-F to maximize the immune responses against the PSA tumor-antigen.

Here we show preclinical data characterizing PROSTVAC® activity in mice. Treatment with either PROSTVAC™-V or PROSTVAC™-F induced PSA-specific antibody and T cell responses; however, PSA-specific responses were further increased by the prime/boost strategy, particularly with respect to the frequency of responding CD8 T cells. These CD8 T cells produced IFN-gamma and degranulated in an antigen-specific manner. Furthermore, PROSTVAC® treatment resulted in strong efficacy in a mouse model of prostate cancer. In this model, treatment with PROSTVAC resulted in anti-tumor efficacy accompanied by a Th1-biased response against PSA. In contrast, growth of tumors in control mice induced only non-protective PSA-specific responses with strong Th2 bias.

Overall, these animal studies help define the activity and mechanism of action of PROSTVAC® which is currently being evaluated in the clinic.

R.B. Rountree and S.J. Mandl contributed equally to this work.

Citation Format: Ryan B. Rountree, Stefanie J. Mandl, Joseph Cote, Tracy dela Cruz, Thierry Giffon, Evan Gordon, Susan P. Foy, John R. Lombardo, Erica Trent, Reiner Laus, Alain Delcayre. Active immunotherapy with PROSTVAC® demonstrates potent antitumor efficacy in a mouse model of prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A21.
Abstract A33: Combination immunotherapy with anti-CD40 mAb and MPL results in T cell-independent antitumor effects against B16 melanoma in mice.
Authors: Voort Tyler Van De , Sondel Paul , Felder Mildred , Young Richard , Kalogriopoulos Nicholas , Rakhmilevich Alexander
Published: August 2014

Combination immunotherapies are promising candidates for clinical testing. In this study, monophosphoryl lipid A (MPL), a nontoxic derivative of LPS and agonist of Toll-like receptor (TLR) 4, was tested in combination with an agonistic anti-CD40 monoclonal antibody (anti-CD40) to assess the antitumor synergy between the two agents. We show that anti-CD40 is capable of priming mouse macrophages for subsequent ex vivo activation by MPL to an extent comparable to a TLR9 agonist, CpG. When given intratumorally (i.t.) to C57BL/6 mice bearing subcutaneous B16 melanoma, anti-CD40 and MPL induced synergistic antitumor effects. When administered i.t. into a primary tumor, anti-CD40 and MPL also slowed the growth of a secondary tumor growing simultaneously at a distant site in both immunocompetent mice and mice depleted of T cells. Taken together, our results show that the antitumor effects of anti-CD40 are enhanced by subsequent treatment with MPL, even in T cell-deficient hosts. These data suggest that anti-CD40+MPL could be a clinically promising immunotherapy for immunosuppressed cancer patients.

Citation Format: Tyler Van De Voort, Paul Sondel, Mildred Felder, Richard Young, Nicholas Kalogriopoulos, Alexander Rakhmilevich. Combination immunotherapy with anti-CD40 mAb and MPL results in T cell-independent antitumor effects against B16 melanoma in mice. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A33.
Abstract A36: Treatment of established dermal murine B16F10 melanoma with an attenuated Toxoplasma gondii eliminates the treated tumor and stimulates systemic antitumor immunity.
Authors: Fiering Steven , Baird Jason R. , Byrne Katelyn , Lizotte Patrick , Mullins David , Jo turk Mary
Published: August 2014

While the surgical removal of dermal melanoma cures that lesion, it does nothing to stimulate antitumor immunity that could potentially identify and eliminate occult metastatic disease. An immune based treatment that eliminates the primary dermal melanoma could also potentially generate systemic immunity that will protect against metastatic disease. We have utilized an attenuated strain of Toxoplasma gondii (cps) to break tumor-mediated immunosuppression, stimulate an antitumor immune response that eliminates the dermal tumor, and generate systemic antitumor immunity that leads to rejection of subsequent dermal or intravenous challenges with B16F10. T. gondii is an obligate intracellular eukaryotic parasite that infects virtually any mammalian species. The cps strain is a uracil auxotroph that can be grown in vitro but is unable to replicate in vivo. Despite its lack of infectivity, it enters cells and stimulates a strong T-cell mediated immune response characterized by long lasted CD8 effector cells. The presence of cps in the tumor microenvironment modifies the phenotype of tumor infiltrating leukocytes, and along with the expected anti-Toxoplasma immune response there is antigen-spreading so that tumor antigens are responded to and the immune system recognizes subsequent tumor challenges when there is no associated cps. The treatment requires CD8 and NK cells for efficacy but does not require CD4 cells. The treatment also requires that the host express IL-12 and Ifn-g. The treatment requires live cps for efficacy and is effective in mice that are latently infected with another strain of T. gondii, so it could function in the high percentage of humans with latent T. gondii infection and an established immune response against T. gondii.

Citation Format: Steven Fiering, Jason R. Baird, Katelyn Byrne, Patrick Lizotte, David Mullins, Mary Jo turk. Treatment of established dermal murine B16F10 melanoma with an attenuated Toxoplasma gondii eliminates the treated tumor and stimulates systemic antitumor immunity. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A36.
Abstract A43: Therapeutic efficacy of antitumor monoclonal antibodies combined with chemotherapy depends on innate immunity and NK1.1- innate lymphoid cells.
Authors: Moskalenko Marina , Pan Michael , Hashimoto Daigo , Mortha Arthur , Bernardo Sebastian G. , Leboeuf Marylene , Houghton Alan , Wolchok Jedd , Burakoff Steven , Merad Miriam , Saenger Yvonne M.
Published: August 2014

Combination regimens incorporating chemotherapy and anti-tumor monoclonal antibodies are in wide clinical use but mechanisms of action are unknown. A better mechanistic understanding would enhance clinical protocols. We treated established melanomas with cyclophosphamide (CY) in combination with an antibody targeting tyrosinase related protein 1 (TRP1), a melanoma differentiation antigen. Therapeutic activity is immune mediated as Fc gamma receptors are required for efficacy. Immune responses can be innate or adaptive and, using Rag 1-/- mice deficient in B and T lymphocytes, we find that the innate immune system is sufficient for tumor clearance. Classic effector cells of the innate immune system include lymphocytes, of which the largest population is NK1.1+ natural killer (NK) cells, and macrophages. NK cells, surprisingly, are not critical as depletion of NK1.1+ cells did not significantly impair anti-tumor effect. In contrast, elimination of non-classical NK1.1- innate lymphocytes, through deletion of the Interleukin 2 (IL2) receptor common gamma chain required for their development, or depletion via antibody targeting pan lymphocyte marker Thy1.2 in Rag 1-/- mice, impairs efficacy of combination therapy. Non-classical NK1.1-Thy1.2+ innate lymphocytes have been implicated in leukocyte infiltration into tissues. We find that depletion of Thy1.2+ cells diminishes entry of Thy 1.2- leukocytes into melanomas treated with chemotherapy and alters the phenotype of infiltrating myeloid cells. Thus, our data highlights a novel role for non-classical innate lymphocytes in the treatment of solid malignancies with monoclonal antibody and chemotherapy.

Citation Format: Marina Moskalenko, Michael Pan, Daigo Hashimoto, Arthur Mortha, Sebastian G. Bernardo, Marylene Leboeuf, Alan Houghton, Jedd Wolchok, Steven Burakoff, Miriam Merad, Yvonne M. Saenger. Therapeutic efficacy of antitumor monoclonal antibodies combined with chemotherapy depends on innate immunity and NK1.1- innate lymphoid cells. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A43.
Abstract A45: Inflammatory biomarker c-reactive protein in radiotherapy-induced skin toxicities of breast cancer patients.
Authors: Rodriguez-Gil Jorge L. , Cooley Anne , Thomas Venetta , Takita Cristiane , Wright Jean , Poitevien Martine , Allen Glenn O. , Reis Isildinha M. , Zhao Wei , Hu Jennifer J.
Published: August 2014

Purpose: Post-surgery adjuvant radiotherapy (RT) significantly reduces recurrence and metastasis of breast cancer. However, many patients experience early adverse skin reactions (EASRs) that impact quality of life. This study evaluated an inflammatory biomarker C-reactive protein (CRP) in RT-induced EASRs in breast cancer patients undergoing RT.

Methods: We recruited 159 breast cancer patients undergoing RT after breast conserving surgery. The pre- and post-RT plasma CRP levels were measured using a highly-sensitive ELISA CRP assay. RT-induced EASRs were assessed at weeks 3 and 6 using the National Cancer Institute Common Toxicity Criteria (v3.0).

Results: RT-induced grade 2+ skin toxicities were observed in 8 (5%) and 79 (50%) patients at weeks 3 and 6, respectively. Significantly higher proportions of African Americans developed grade 3 skin toxicities (13.8% vs. 2.3% in Whites) at week 6. In multivariate analysis, there was a suggestive association between grade 2+ skin toxicities at week 3 and >2 mg/L pre-RT CRP (OR=4.68, 95%CI=0.49, 44.94). However, grade 2+ skin toxicities at week 6 were significantly associated with elevated: CRP > 1 mg/L (OR=3.26; 95%CI=1.35, 7.85, p=0.01), obesity (OR=2.39; 95%CI=1.19, 4.83, p=0.02), or combined both factors (OR=7.80; 95%CI=2.59, 23.49, p<0.001).

Conclusion: This is the first study to suggest that CRP has value as an inflammatory biomarker in RT-induced EASRs, particularly combined with obesity. Future larger studies are warranted to validate our findings and facilitate the discovery and development of anti-inflammatory agents to protect normal tissue from RT-induced adverse effects and improve quality of life in breast cancer patients undergoing RT.

Citation Format: Jorge L. Rodriguez-Gil, Anne Cooley, Venetta Thomas, Cristiane Takita, Jean Wright, Martine Poitevien, Glenn O. Allen, Isildinha M. Reis, Wei Zhao, Jennifer J. Hu. Inflammatory biomarker c-reactive protein in radiotherapy-induced skin toxicities of breast cancer patients. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A45.
Abstract A47: Increased levels of IL-12, IL-23 and IL-18 in skin expressing HPV16 E7 protein.
Authors: Gosmann Christina , Mattarollo Stephen R. , Blumenthal Antje , Frazer Ian H.
Published: August 2014

As a consequence of infection with human papillomavirus (HPV), worldwide more than 0.25 million women die of cervical cancer each year. Chronic HPV infection is thought to create an immune suppressive environment preventing successful elimination of the virus, and there is no cure for persistent virus infection and resulting lesions. In a previous study using a mouse model of HPV16 E7 protein-induced epithelial hyperplasia, we demonstrated that IFN-γ plays a crucial role in suppressing an effective immune response against E7 in the skin (Mattarollo et al., J Immunol 2010, 184(3):1242-50). In support of these findings, we now show significantly higher levels of IFN-γ in E7-expressing compared to wild type skin. To investigate the mechanisms that drive IFN-γ production in E7 transgenic skin, we assessed the presence of the inflammatory cytokines IL-12, IL-23 and IL-18, which are well known potent inducers of IFN-γ. Quantitative analysis of skin mRNA levels and of supernatants from in vitro skin explant culture revealed significantly increased expression and secretion of IL-12, IL-23 and IL-18 in E7 positive compared to wild type skin. In contrast, levels of IL-6 protein and of pro-IL-1β mRNA and protein were reduced in E7 transgenic skin. We hypothesise that in chronically HPV-infected skin, a downregulation of IL-6 and IL-1β expression aids immune evasion, while IL-12, IL-23 and IL-18 induce immune suppressive IFN-γ, thus promoting persistent virus infection and allowing for the progression to cervical cancer.

Citation Format: Christina Gosmann, Stephen R. Mattarollo, Antje Blumenthal, Ian H. Frazer. Increased levels of IL-12, IL-23 and IL-18 in skin expressing HPV16 E7 protein. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A47.
Abstract A48: Novel dual mode fluorine MRI, NIR fluorescent probe for noninvasive detection of tumor-associated inflammation.
Authors: Balducci Anthony , Wen Yi , Zhang Yang , Helfer Brooke M. , Hitchens Kevin , Meng Wilson , Janjic Jelena , Wesa Amy
Published: August 2014

Tumor-associated macrophage are active in both tumor progression and remission processes, affecting prognosis depending on the nature of their involvement. Imaging macrophage recruitment and persistence to gauge tumor from normal host tissue is an area of great interest. Herein we propose the use of a novel dual mode fluorine magnetic resonance imaging (MRI), near infrared (NIR) fluorescent probe for the non-invasive detection of tumor associated inflammation. The use of this technique allows for rapid optical assessment of tumor associated macrophage as well as the specificity and detailed resolution provided by pairing 19F and conventional 1H MRI. Upon administration of the 19F/NIR reagent, tumors were visible at 6h. Both the liver and spleen were also visible due to clearance through the reticuloendothelial system. Use of the dual mode reagent was also compatible with MRI visualization, where detection of inflammation was in the periphery of, and not integral to, the tumor itself, information that could not be detected by optical means. Upon resection of the tumor, liver, spleen and other regions of interest fluorescence detection within the organs/tissue correlated with fluorine content and agreed with macrophage infiltrates and regions of reagent clearance. Flow cytometric analysis of whole blood show the preferential labeling of the macrophage population and immunofluorescent analysis of labeled macrophage further confirms cellular labeling. Dual functioning contrast agents enable both quick monitoring and sensitive quantification when evaluating the tumor microenvironment and potential changes in macrophage infiltrates as a result of therapeutic intervention.

Citation Format: Anthony Balducci, Yi Wen, Yang Zhang, Brooke M. Helfer, Kevin Hitchens, Wilson Meng, Jelena Janjic, Amy Wesa. Novel dual mode fluorine MRI, NIR fluorescent probe for noninvasive detection of tumor-associated inflammation. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A48.
Abstract A50: Inhibition of IL-8 production by pancreatic cancer cells with marine natural products.
Authors: Guzman Esther A. , Pitts Tara , Wright Amy E.
Published: August 2014

Pancreatic cancer presents one of the most negative prognoses of all cancers, as it has usually metastasized by the time a patient is diagnosed. Therefore, almost as many deaths as new cases are expected each year. Although combination therapy shows some promise, the need for new drugs to treat the disease is pressing. Harbor Branch Oceanographic Institute (HBOI) has developed a unique library of marine samples and its research program seeks to tap into the biological diversity of the oceans to find potential anti-cancer drugs. Inflammation has been connected to pancreatic cancer development and progression. A recent study has shown that IL-8 mediates the angiogenesis of tumors arising from Ras-mutations. Ras is a proto-oncogene that is mutationally activated in 90% of pancreatic adenocarcinomas. Overexpression of IL-8 in pancreatic tumors is thought to promote tumor angiogenesis and to activate survival signaling pathways. Given our interest in finding new therapies for pancreatic cancer, we set up a 96-well cell-based assay to screen our library of marine natural products for those with the ability to inhibit IL-8 production by pancreatic cancer cells. A thousand fractions were screened resulting in the identification of marine natural products with the ability to inhibit IL-8 secretion by the BxPC-3 pancreatic cancer cell line. Studies are currently underway to determine if this inhibition leads to an inhibition in angiogenesis or affects cell proliferation.

Citation Format: Esther A. Guzman, Tara Pitts, Amy E. Wright. Inhibition of IL-8 production by pancreatic cancer cells with marine natural products. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A50.
Abstract A59: Block/homo polyplex micelle-based GM-CSF gene therapy via intraperitoneal administration elicits antitumor immunity against peritoneal dissemination and exhibits safety potentials in mice and monkeys.
Authors: Ohgidani Masahiro , Furugaki Koichi , Kentaro Shinkai , Kunisawa Yumi , Itaka Keiji , Kataoka Kazunori , Nakano Kenji
Published: August 2014

A block/homo-mixed polyplex micelle, comprising of cationic homo polymer: {N'-[N-(2-aminoethyl)-2-aminoethyl]aspartamide} P[Asp(DET)] and block copolymer: polyethylene glycol (PEG) -P[Asp(DET)], has been reported to exhibit the efficient transgene expression in vivo by intratracheal and systemic administration. In the present study, we investigated the potential of immunogene therapy by intraperitoneal (i.p.) administration of block/homo polyplex micelles for peritoneal dissemination. For evaluation of transgene expression in vivo, block/homo polyplex micelles showed 12-fold higher level in luciferase expression evaluated by bioluminescence imaging system at 24 h after the i.p. administration compared with block polyplex micelles in nude mice bearing peritoneal dissemination. The distribution of polyplex micelles in tumor nodules was similarly present for both polyplex micelles, where the intracellular uptake of plasmid DNA was detected for block/home polyplex micelles but little for block polyplex micelles. The i.p. administration of block/homo polyplex micelles encapsulating granulocyte macrophage colony stimulating factor (GM-CSF) gene elicited GM-CSF expression dominantly in tumors and less in normal organs (liver and spleen), inhibited the tumor growth and prolonged survival rate for the mice harboring disseminated pancreatic cancer more significantly compared with the mock. The antitumor effect of GM-CSF gene therapy was mediated via the activation of natural killer cells. For safety evaluation, block/homo polyplex micelles indicated almost no adverse events for patho-physical findings and blood examinations in mice and cynomolgus monkeys, although slight increases in serum fibrinogen were observed in the monkey model. In conclusion, block/homo polyplex micelle-based immunogene therapy via i.p. administration may be a safe and effective approach for suppressing intractable peritoneal dissemination.

Citation Format: Masahiro Ohgidani, Koichi Furugaki, Shinkai Kentaro, Yumi Kunisawa, Keiji Itaka, Kazunori Kataoka, Kenji Nakano. Block/homo polyplex micelle-based GM-CSF gene therapy via intraperitoneal administration elicits antitumor immunity against peritoneal dissemination and exhibits safety potentials in mice and monkeys. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A59.
Abstract A6: The synergy between IL-12 priming of CD8 T cells and lymphodepletion is mediated by host IL-7.
Authors: Johnson Christopher Bryce , May Bennett R. , Cloud Colleen A. , Rubinstein Mark P. , Cole David J.
Published: August 2014

Adoptive T-cell transfer therapy (ACT) is a promising approach for the treatment of metastatic melanoma. Using the pmel-1 transgenic mouse as a source of melanoma-reactive CD8 T-cells, our lab has shown that priming these tumor-specific cells ex vivo with IL-12 (pmelIL-12) prior to ACT results in significant anti-tumor synergy and enhanced persistence in combination with cyclophosphamide (CTX). Here we demonstrate that other currently accepted lymphodepletion approaches, total body irradiation (TBI) alone or in combination with CTX, are also capable of synergizing with ACT of pmelIL-12. Interestingly, all 3 regimens (CTX, TBI and CTX + TBI) showed a similar ability to synergize with pmelIL-12, suggesting a common underlying mechanism. To elucidate the mechanism(s) behind this observed synergy, we evaluated whether the persistence of pmelIL-12 cells transferred into a lymphopenic host required the cytokines IL-7 and IL-15, which are known to be increased in the host post lymphodepletion. We found that the early expansion of pmelIL-12 in an irradiated host was partially dependent on IL-7, but not IL-15, as both the percentage and total number of donor cells recovered from spleens of irradiated hosts 1-week after ACT were greatly diminished in mice treated with an antibody against the IL-7 receptor alpha, CD127, or with an IL-7 neutralizing antibody (clone M25). In vitro these pmelIL-12 cells were able to proliferate in response to IL-7 to a much greater extent than pmel CD8 T-cells activated without IL-12. Together, these findings demonstrate that activated CD8 T cells primed with IL-12 display enhanced responsiveness to IL-7, and that IL-7 is necessary for maximal persistence of these cells in an irradiated host. Therefore, we conclude that the observed synergy between IL-12 priming of CD8 T cells and lymphodepletion is due in part to increased availability of host IL-7 after lymphodepletion.

Citation Format: Christopher Bryce Johnson, Bennett R. May, Colleen A. Cloud, Mark P. Rubinstein, David J. Cole. The synergy between IL-12 priming of CD8 T cells and lymphodepletion is mediated by host IL-7. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A6.
Abstract A86: Inactivation of p110delta PI3K releases potent antitumor immunity.
Authors: Ali Khaled , Soond Dalya , Pinero Roberto , Pearce Wayne , Scudamore Cheryl , Friedman Lori , Turner Martin , Okkenhaug Klaus , Vanhaesebroeck Bart
Published: August 2014

In cancer the tumor suppressive potential of the immune system is limited by the induction of self-tolerance and chronic inflammation promoted through the activity of regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSCs) respectively. The phosphoinositide-3-kinase (PI3K) pathway is very frequently activated in cancer cells, and clinical trials with PI3K inhibitors are ongoing. The p110delta isoform of PI3K is highly enriched in leukocytes in which it regulates various immune functions. p110delta is involved in both the adaptive and innate immune system and p110delta inhibitors may be used to treat a broad range of immune disorders including T cell mediated auto-immune disorders. An expected side effect of long-term p110delta inhibition is, immune suppression, which could pre-dispose to cancer. We now show that paradoxically, genetic or pharmacologic inactivation of p110delta protects mice against tumor growth and metastasis. Blockade of p110delta; inhibits the activation of Treg cells and the accumulation of MDSCs, thus allowing the development of an effective CD8+ T cell-dependent anti-tumor response. These data provide a rationale for the use of p110delta inhibitors as adjuvants to boost anti-tumor immune responses in cancer.

Note: This abstract was not presented at the conference.

Citation Format: Khaled Ali, Dalya Soond, Roberto Pinero, Wayne Pearce, Cheryl Scudamore, Lori Friedman, Martin Turner, Klaus Okkenhaug, Bart Vanhaesebroeck. Inactivation of p110delta PI3K releases potent antitumor immunity. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A86.
Abstract B10: Potential synergistic antitumor activity between sorafenib and lenalidomide in an orthotopic murine liver cancer model.
Authors: Chang Chun-Jung , Ou Da-Liang , Lin Yi-Jang , Cheng Ann-Lii , Hsu Chiun
Published: August 2014

The immune modulatory drug lenalidomide has shown promising anti-tumor activity in a clinical trial of patients with advanced hepatocellular carcinoma (HCC). The present study explored whether lenalidomide can enhance the anti-tumor activity of sorafenib, the standard molecular targeted therapy for HCC. An orthotopic liver cancer model was developed by injecting the BNL liver cancer cells (from ATCC) into the liver capsule of BALB/c mice. Mice were treated by sorafenib by daily gavage or lenalidomide by daily intra-peritoneal injection, and the anti-tumor efficacy of single-agent or combination treatment was measured by change in tumor volume and animal survival. The number of IFN-γ expressing T-cell sub-populations in tumor-infiltrating lymphocytes (TILs) and the number of IFN-γ expressing tumors-specific CD8+ T cells in splenocytes derived from tumor-implanted mice were measured by flow cytometry. Depletion of relevant T cell sub-populations or cytokines was done by co-administration of relevant antibodies with study drug treatment. TUNEL assay and immunohistochemical study on tumor tissues were done to measure apoptosis and to explore potential biomarkers (Ki67, CD31). Combination of sorafenib (5 mg/kg/day) and lenalidomide (50 mg/kg/day) produced significant synergistic anti-tumor efficacy in terms of tumor growth delay and animal survival. This synergistic effect was associated with a significant increase in IFN-γ expressing CD8+ lymphocytes in TILs and splenocytes. In addition, TILs derived from mice in the combination treatment group had higher number of granzyme- or perforin- expressing CD8+ T cells, compared with vehicle- or single-agent-treatment groups. Combination treatment was associated with a significant increase in apoptotic tumor cells and decrease in microvessel density in tumor tissue. Finally, the synergistic anti-tumor effect was abolished after CD8 depletion. The combination treatment was well tolerated except that leucopenia was common. Our data indicate that lenalidomide can enhance the anti-tumor effects of sorafenib in HCC through its immune modulatory effects and CD8+ T cells play an important role in the anti-tumor synergism. (supported by grants NSC 101-2321-B-002 -014 and NSC 101-2314-B-002-162)

Citation Format: Chun-Jung Chang, Da-Liang Ou, Yi-Jang Lin, Ann-Lii Cheng, Chiun Hsu. Potential synergistic antitumor activity between sorafenib and lenalidomide in an orthotopic murine liver cancer model. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B10.
Abstract B2: T cell costimulation in cancer immunotherapy with anti-CD137 monoclonal antibodies is mediated by K63-polyubiquitin-dependent signals from endosomes.
Authors: Martinez-Forero Ivan , Azpilicueta Arantza , Bolaños-Mateo Elixabet , Nistal-Villan Estnislao , Palazon Asis , Teijeira Alvaro , Perez-Chacon Gema , Morales-Kastresana Aizea , Murillo Oihana , Jure-Kunkel Maria , Zapata Juan Manuel , Melero Ignacio
Published: August 2014

Agonist anti-CD137(4-1BB) mAbs enhance CD8-mediated antitumor immunity. Agonist anti-human CD137 mAbs covering four distinct epitopes on the CD137 glycoprotein co-stimulated T cell activation irrespective of the engaged epitope or its interference with CD137L binding. CD137 perturbation with all these agonist mAbs resulted in antigen and antibody internalization towards a vesicular compartment. Internalization was observed in activated T cells from humans and mice, not only in culture but also in antibody-injected living animals. These in vivo experiments were carried out upon systemic intravenous injections with anti-CD137 mAbs and showed internalization in tumor-infiltrating lymphocytes and in activated human T cells transferred to mice. CD137-internalization required K63-polyubiquitination and endocytosed CD137-containing deposits were decorated with K63-polyubiquitins. CD137 stimulation activates NF-kB through a K63-linked polyubiquitination-dependent route and CD137-associated TRAF2 becomes K63-polyubiquitinated. Consistent with a role for TRAF2 in CD137 signalling, transgenic mice functionally deficient in TRAF2 show a delayed immunotherapeutic activity of anti-CD137 mAbs

Citation Format: Ivan Martinez-Forero, Arantza Azpilicueta, Elixabet Bolaños-Mateo, Estnislao Nistal-Villan, Asis Palazon, Alvaro Teijeira, Gema Perez-Chacon, Aizea Morales-Kastresana, Oihana Murillo, Maria Jure-Kunkel, Juan Manuel Zapata, Ignacio Melero. T cell costimulation in cancer immunotherapy with anti-CD137 monoclonal antibodies is mediated by K63-polyubiquitin-dependent signals from endosomes. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B2.
Abstract B21: Immune-based treatment of ovarian cancer in a mouse model with attenuated Toxoplasma gondii.
Authors: Fiering Steven , Baird Jason R. , Fox Barbara , Lizotte Patrick , Sanders Kiah , Conjeo-Garcia Jose , Bzik David
Published: August 2014

Ovarian cancer is generally diagnosed at stage 3 or 4 metastatic disease. The disease course of ovarian cancer is characterized by a remission period following surgery and chemotherapy, but the remission generally only lasts 1-2 years and the relapse is very difficult to treat, so the disease has very poor 5 year survival rates. Effective stimulation of an antitumor immune response during the remission period could eliminate occult metastatic disease and therefore developing immunotherapy approaches for ovarian cancer that can be applied during the remission period is of considerable interest. We have utilized the ID8 based ovarian cancer model in the form of the highly aggressive ID8/Vegf/Defb29 subline to test the ability of an attenuated strain of T. gondii (cps) to stimulate an anti-tumor immune response. We show that following establishment of the tumor by IP injection of tumor cells, introduction of cps into the peritoneal cavity significantly slows the development of the disease. cps predominantly invades immunosuppressive phagocytes in the tumor microenvironment and modifies these and newly recruited phagocytes to be immunostimulatory. The phagocytes are now much more efficient antigen processers and presenters, the immune system is freed from immunosuppression, and the antitumor immune response is activated. The treatment efficacy is associated with a large increase of tumor antigen-specific CD8 T cells and these T cells demonstrate antitumor activity in a transfer experiment and tumor challenge. cps is nontoxic, even in animals with no adaptive immune system, and is a fully attenuated but highly effective platform for developing cancer treatment vaccines. Further developed and applied, cps could be the basis for an autologous tumor vaccine approach that has the potential to improve ovarian cancer outcomes.

Citation Format: Steven Fiering, Jason R. Baird, Barbara Fox, Patrick Lizotte, Kiah Sanders, Jose Conjeo-Garcia, David Bzik. Immune-based treatment of ovarian cancer in a mouse model with attenuated Toxoplasma gondii. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B21.
Abstract B30: Cross-priming of CD8+ T cells is controlled by dipeptidyl peptidase 3 and thimet oligopeptidase 1 present in necrotic cells.
Authors: Gamrekelashvili Jaba , Kapanadze Tamar , Wissing Josef , Ma Chi , Jaensch Lothar , Korangy Firouzeh , Greten Tim F.
Published: August 2014

Cross-priming of CD8+ T cells and generation of effector immune responses is pivotal for tumor immunity, successful anticancer vaccination and therapy. We have discovered a novel molecular mechanism operating in antigen donor cells, which regulates cross-priming of CD8+ T cells during primary sterile necrosis and thereby controls adaptive immune responses. We show that cellular peptidases, dipeptidyl peptidase 3 (DPP-3) and thimet oligopeptidase 1 (TOP-1) present in non-immunogenic necrotic cells eliminate proteasomal degradation products and block antigen cross-presentation. While sterile necrotic tumor cells fail to induce CD8+ T cell responses, their non-immunogenicity can be reversed in vitro and in vivo by inactivation of peptidases, DPP-3 and TOP-1. Thus control of cross-priming and thereby immunogenicity of primary sterile necrosis relies on the proteasome dependent oligopeptide generation and functional status of peptidases in antigen donor cells.

Citation Format: Jaba Gamrekelashvili, Tamar Kapanadze, Josef Wissing, Chi Ma, Lothar Jaensch, Firouzeh Korangy, Tim F. Greten. Cross-priming of CD8+ T cells is controlled by dipeptidyl peptidase 3 and thimet oligopeptidase 1 present in necrotic cells. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B30.
Abstract IA13: Phase I trial of targeted therapy with PSA-TRICOM vaccine (V) and ipilimumab (ipi) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC).
Authors: Gulley James L. , Madan Ravi A. , Tsang Kwong Y. , Jochems Caroline , Dahut William L. , Schlom Jeffrey
Published: August 2014

Background: Immunotherapy is an emerging therapeutic option for mCRPC and has demonstrated improved survival. Immunologic combinations are a logical next step in the clinical development. PSA-TRICOM V, composed of poxviral vectors encoding PSA and 3 costimulatory molecules (ICAM-I, LFA-3, and B7.1), has shown evidence of clinical activity in mCRPC and is being tested in a phase III study (NCT01322490). Ipi, which blocks CTLA-4, a T-cell coinhibitory receptor, has clinical activity in mCRPC as monotherapy and has also been shown to enhance antitumor responses in combination with V in preclinical studies.

Methods: We completed a phase I dose-escalation trial, with a subsequent expansion phase, to assess the safety and tolerability of escalating doses of ipi in combination with a fixed dose of PSA-TRICOM V. Pts with mCRPC received vaccinia PSA-TRICOM subcutaneously on day 1 of cycle 1, with subsequent monthly boosts of fowlpox PSA-TRICOM starting on day 15. Intravenous ipi was given monthly x 6 starting at day 15, in doses of 1, 3, 5, and 10 mg/kg. Our primary goal was to assess the safety of the combination.

Results: We completed enrollment with 30 pts (24 of whom were chemotherapy-naïve) and did not identify any dose-limiting toxicity. 21 pts had grade ≥ 2 immune-related adverse events, including diarrhea or colitis, rash, raised aminotransferases, endocrinopathy, and neutropenia. Only 1 of the 6 pts previously treated with chemotherapy had a PSA decline from baseline. Of the 24 pts who were chemotherapy-naïve, 14 (58%) had PSA declines from baseline, of which 6 were > 50%. While the median predicted survival was about 18 months, based on a validated nomogram, actual median OS exceeded 34 months in this phase I study. A previous 32 pt study at the same institution of V alone in the same population (predicted survival 17.4 months) had an OS of 26.6 months.

Conclusions: The use of a V targeting PSA that also enhances costimulation of the immune system did not seem to exacerbate the immune-related adverse events associated with ipi. There is a suggestion of clinical activity for the combination; however, randomized trials are needed to further assess clinical outcomes of the combination of ipi and V in mCRPC.

ClinicalTrials.gov registry number: NCT00113984

Ref: Madan et al., Lancet Oncology 2012.

Citation Format: James L. Gulley, Ravi A. Madan, Kwong Y. Tsang, Caroline Jochems, William L. Dahut, Jeffrey Schlom. Phase I trial of targeted therapy with PSA-TRICOM vaccine (V) and ipilimumab (ipi) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC). [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr IA13.
Abstract IA25: Local immunomodulation at a single site of tumor generates a therapeutic immune response that cures metastatic disease at distant sites, including the brain.
Authors: Marabelle Aurelien , Kohrt Holbrook , Levy Ronald
Published: August 2014

TLR-9 ligand (CpG) injected directly into a tumor can induce a therapeutic immune response. However regulatory T-cells (Tregs) eventually inhibit the anti-tumor immune response and thereby limit the power of cancer immunotherapies. We found that Tregs within the tumor preferentially express the cell surface markers CTLA-4 and OX40. We show that intra-tumoral co-injection of anti-CTLA-4 and anti-OX40 together with CpG depletes tumor-infiltrating Tregs. This in situ immunomodulation performed with low doses of antibodies into a single tumor generates a systemic anti-tumor immune response able to eradicate disseminated disease in mice, including established CNS lymphoma with leptomeningeal metastases, sites usually considered as sanctuaries for conventional systemic therapies.

These results support a paradigm shift in cancer therapy where instead of using monoclonal antibodies to target cancer cells systemically, we use monoclonal antibodies at low doses to target the tumor infiltrative immune cells locally. The consequences of this strategy are the generation of a more potent anti-tumor immune response, and the expectation of less toxicity.

On the basis of our preclinical results we are now opening a Phase I/II clinical trial testing the combination of local low dose radiotherapy with escalating doses of Ibilumimab (anti-CTLA4). Patients with metastatic melanoma, colorectal cancer and lymphoma are eligible. The intention will be to find a safe dose of the antibody when injected locally together with radiotherapy and then to assess the patients for immune responses and for tumor responses at uninjected sites of disease.

Citation Format: Aurelien Marabelle, Holbrook Kohrt, Ronald Levy. Local immunomodulation at a single site of tumor generates a therapeutic immune response that cures metastatic disease at distant sites, including the brain. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr IA25.