bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3806: The pattern of NKG2DL expressions determines immunogenicity and antitumor effect of protein-bound polysaccharide-K in tumor-bearing mouse models
Authors: Takehara Tomohiro , Soejima Kenzo , Betsuyaku Tomoko , Yoshimura Kiyoshi 
Published: August 2018

Abstract
Background and Aim: Natural killer group 2, member D ligands (NKG2DLs) have paradoxical immunological characteristics, exerting both immune-stimulatory and immune-suppressive effects on T cell activation. First, we attempted to determine the relationship between the antitumor effect of protein-bound polysaccharide-K (PSK) in a tumor-bearing mouse model and the expression profile of NKG2DLs on a tumor. Next, we investigated whether NKG2DL expression on tumor cells affects T cell activation by examining the expression of NKG2D on and IFN-γ production in CD8+ T cells in mice bearing NKG2DL–expressing and NKG2DL–nonexpressing tumors.Materials and Methods: PSK was administered to evaluate its effectiveness against tumor growth. The expression of Rae-1 and H60 were analyzed in the cell lines. Results: PSK showed the highest antitumor effects in mice implanted with cells expressing neither Rae-1 nor H60. PSK had little antitumor effect in mice implanted with cells expressing both Rae-1 and H60. A correlation between the expression of NKG2DLs and the antitumor effect of PSK was observed. After PSK administration, INF-γ production in CD8+ T cells increased in mice with cells expressing neither Rae-1 nor H60, but did not change in mice implanted with cells expressing both Rae-1 and H60.Conclusion: we demonstrated that the expression pattern of NKG2DLs affects tumor immunity and the efficacy of immunotherapy in a tumor-bearing mouse model. In particular, the expression of H60 and Rae-1 family members may be an immunosuppressive factor. Further analysis is required to gain a better understanding of the mechanism of interaction between NKG2D expressed on immune effector cells and H60/Rae-1 expression on tumors. Although NKG2DL expression may represent a marker predicting response to immunotherapy, further studies in humans are required to validate this finding in the clinical setting.
Citation Format: Tomohiro Takehara, Kenzo Soejima, Tomoko Betsuyaku, Kiyoshi Yoshimura. The pattern of NKG2DL expressions determines immunogenicity and antitumor effect of protein-bound polysaccharide-K in tumor-bearing mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3806.
Abstract 3808: Interrogation and modulation of the immunosuppressive activity of human TAM-like macrophages using in vitro cultures
Authors: Gallagher Laura E. , Hall Andrew , Patience Lauren A. , Janicova Lucia , Anderton Stephen 
Published: August 2018

Abstract
Tumor Associated Macrophages (TAMs), characteristic of an M2-like immune-suppressive phenotype, can induce proliferation and survival of tumor cells, facilitate angiogenesis, and suppress anti-tumor immune responses via expression of co-inhibitory molecules (e.g. PD-L1) and cytokines (e.g. IL-10, TGF-β). TAMs are therefore a highly attractive target of innovative cancer immunotherapies. Understanding the ability of pre-clinical candidate compounds to reverse TAM (M2-like)-mediated immune suppression and the potential for reprogramming of M2-like macrophages to a M1-like phenotype is key in the development of effective TAM-targeted cancer immunotherapies. Here we outline development of an assay to assess the capabilities of pre-clinical compounds to reverse M2 macrophage-mediated immune suppression.
Monocytes were isolated from whole blood obtained from healthy volunteers and cultured under M2-polarising conditions. The resulting macrophages were phenotypically characterized and then used in co-culture with autologous PBMC, stimulated through T cell receptor ligation. Resulting cytokine production was assessed, alongside CD4+ and CD8+ T cell viability and cell cycle status (flow cytometry).
M2-like macrophages polarized with M-CSF displayed an immune suppressive phenotype as shown by their production of IL-10 and their inhibition of IFN-γ production by, and cell cycle status of, T cells in co-culture assays. This suppressive activity was only partially reversed by PD-1-blockade. Modifications to the macrophage polarization protocol were seen to alter the resulting macrophage cell surface phenotype (e.g. expression levels of PD-L1, TIM-3 and CD200R) and their suppressive activity in the co-culture assay. These cell surface phenotypes broadly reflected those seen amongst tumor-derived macrophages from renal and ovarian carcinoma patients (CD14+ CD163+ with expression of TIM-3 and LAG-3). Moreover, compound-mediated changes in functionality seen with macrophages polarized from healthy PBMC monocytes could also be seen using patient-derived material.
The assay outlined here therefore provides a M-o-A human in vitro system to test novel compound activity (either singly or in combination) upon TAM-like macrophage generation, phenotype and suppressive function. This allows selection of the most efficacious compounds for further investigation using patient-derived immune cells.
Citation Format: Laura E. Gallagher, Andrew Hall, Lauren A. Patience, Lucia Janicova, Stephen Anderton. Interrogation and modulation of the immunosuppressive activity of human TAM-like macrophages using in vitro cultures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3808.
Abstract 3810: Ovarian tumor-induced changes in macrophage phenotype are associated with tumor metastasis
Authors: Yellapa Aparna , Bitterman Pincas , Sharma Sameer , Basu Sanjib , Barua Animesh 
Published: August 2018

Abstract
Background: Ovarian cancer (OVCA) differs from other gynecologic malignancies in its dissemination pattern where the tumor migrates in a diffuse intrapelvic and -abdominal manner. OVCA also triggers a variety of cellular and/or humoral immune responses to a variety of tumor-associated proteins. OVCA is mostly diagnosed at late stages where tumor has already metastasized, indicating an escape from immune responses. Despite several immune response factors, ovarian tumor metastasizing to omentum indicates presence of one or more immune evasion mechanisms. Immune system recognizes and eliminates pathogenic products and tumor cells and macrophages play a critical role in this process. Macrophages in tumor condition express anti-inflammatory cytokines that induce immune suppression. Cellular immune response maximizes killing efficacy of macrophages and proliferation of CD8+ T cells. M2 macrophages are tumor-associated macrophages involved in active growth and progression of tumors. However, the mechanism of ovarian tumor-induced changes in M1 macrophages to M2 phenotype is not well understood. Therefore, the goal of our study was to determine the tumor-induced changes in macrophage phenotype and cytotoxic T cells in association with OVCA metastasis.
Materials and Methods: This study was performed in exploratory design using ovarian specimen from normal subjects (60-80 years, n=10) and ovarian malignant tumors at early (n=16, 4 from each histologic type of OVCA) and late stages (n =20) as well as omental tissues from normal (n=3) and OVCA patients (n= 3). Tissue specimen were processed for immunohistochemistry (IHC), Western blotting (WB) and gene expression studies. Expression of M1 and M2 macrophages, CD8 and PI3K was examined by immunohistochemistry (IHC), Western blotting (WB) and qPCR.
Results: Compared with normal ovaries, more M1 and M2 macrophages were localized in tumor tissues. However, compared with early-stage OVCA, the frequency of M2 macrophages was significantly higher in ovarian tumors and omental tissues at late OVCA. Intensity of PI3K was also higher in ovarian tumors and omental tissues at late OVCA compared with normal ovarian tissues. Frequency of CD8+T cells was higher in tumor ovarian samples in comparison with normal ovarian tissues.
Conclusion: Results of this study suggest that the growth and metastasis of ovarian tumors are associated with increased conversion of M1 macrophages to M2 phenotype. This change in macrophage phenotype may be mediated by the increase in PI3K expression.
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Citation Format: Aparna Yellapa, Pincas Bitterman, Sameer Sharma, Sanjib Basu, Animesh Barua. Ovarian tumor-induced changes in macrophage phenotype are associated with tumor metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3810.
Abstract 3814: TriTACs are novel T cell-engaging therapeutic proteins optimized for the treatment of solid tumors and for long serum half-life
Authors: Wesche Holger , Aaron Wade , Austin Richard J. , Baeuerle Patrick A. , Jones Adrie , Lemon Bryan , Sexton Kenneth , Yu Timothy 
Published: August 2018

Abstract
T cell engagers are antibody-based therapeutics that transiently tether T cells via the T cell receptor complex (TCR) to surface antigens on tumor cells. This leads to activation of T cells and redirected lysis of the attached target cell. The therapeutic potential of this modality was demonstrated by blinatumomab, a CD19/CD3-bispecific T cell engager approved for the treatment of adult patients with relapsed/refractory acute lymphoblastic leukemia. Despite success of this T cell-engaging therapy in a hematologic malignancy, clinical studies in solid tumors with other T cell engagers have been less encouraging so far. The TriTAC (Tri-specific T cell Activating Construct) platform was developed to address shortcomings of existing T cell engagers, including short serum half-life, limited tissue penetration, and suboptimal activity. TriTAC constructs are made of a single polypeptide designed to bind to a cancer surface antigen, the CD3 epsilon subunit of the TCR, and to human serum albumin. CD3 is bound by a single-chain variable fragment (scFv) while both tumor targeting and albumin binding are achieved by single domain antibodies. The latter allow TriTACs to be very small, stable, and easily produced and purified. Noncovalent binding to serum albumin has been validated as an effective way to extend the serum half-life of other proteins up to several weeks. Even though TriTACs have three binding domains, their overall size is only ~50 kDa, one third of the size of a monoclonal antibody. This is expected to allow for faster diffusion into human tumor tissues than is possible with antibodies given the high interstitial pressure and dense extracellular matrix in solid tumors. TriTACs can induce T cell to kill tumor cells in vitro at single-digit picomolar to femtomolar concentrations with concomitant induction of inflammatory cytokine release and T cell proliferation. TriTACs can diffuse much faster across an extracellular matrix than antibodies, and eradicate tumors in mouse xenograft models supplemented with human T cells. In nonhuman primates, TriTAC molecules have serum half-lives of approximately 4 days, and appear well tolerated.
Citation Format: Holger Wesche, Wade Aaron, Richard J. Austin, Patrick A. Baeuerle, Adrie Jones, Bryan Lemon, Kenneth Sexton, Timothy Yu. TriTACs are novel T cell-engaging therapeutic proteins optimized for the treatment of solid tumors and for long serum half-life [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3814.
Abstract 3817: Improved T cell activation bioassays to facilitate the development of bispecific antibodies and engineered T cell immunotherapies
Authors: Stecha Pete , Garvin Denise , Hartnett Jim , Krishnan Gopal B. , Fan Frank , Cong Mei , Cheng Zhi-jie Jey 
Published: August 2018

Abstract
T cells play a critical role in cell-mediated immunity and can mediate long-term, antigen-specific, effector and memory responses. A variety of immunotherapy strategies have been developed recently that are aimed at inducing, strengthening or engineering T cell responses. These have emerged as promising approaches for the treatment of diseases such as cancer and autoimmunity. Current methods used to measure TCR-mediated T cell proliferation and cytokine production rely on primary PBMCs as a source of T cells, which must be stimulated via co-culture with APCs or anti-TCR/CD3 antibodies. These assays are laborious and highly variable due to their reliance on donor primary cells, complex assay protocols and unqualified assay reagents. As a result, these assays are difficult to establish in quality-controlled drug development settings. To overcome this barrier, we developed two reporter-based bioluminescent T cell activation bioassays that can be used for the development of bispecific antibodies and engineered T cell immunotherapies. The assays consist of Jurkat T cells genetically engineered to express luciferase downstream of either NFAT or IL-2 response elements. The T cell activation bioassays reflect the mechanisms of action of biologics designed to induce TCR and/or CD28-mediated T cell activation, as demonstrated using anti-CD3 and/or anti-CD28 antibodies as well as blinatumomab, a bispecific antibody that simultaneously binds CD3 expressed on T cells and CD19 expressed on malignant B cells. The bioassays are pre-qualified according to ICH guidelines and demonstrate assay specificity, precision, accuracy and linearity required for routine use in potency and stability studies. Finally, our data illustrate the use of reporter-based T cell activation bioassays for characterizing and measuring the activity of engineered chimeric antigen receptor T cells.
Citation Format: Pete Stecha, Denise Garvin, Jim Hartnett, Gopal B. Krishnan, Frank Fan, Mei Cong, Zhi-jie Jey Cheng. Improved T cell activation bioassays to facilitate the development of bispecific antibodies and engineered T cell immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3817.
Abstract 3830: Monoclonal and bispecific antibodies against human insulin-like growth factors in oncology
Authors: Zhao Qi 
Published: August 2018

Abstract
The insulin-like growth factor (IGF) axis plays an important role in cell growth and differentiation. During the past decade, IGF type 1 receptor (IGF-1R) was deemed a promising target for cancer therapy. The major challenge is that abnormal activation of IGF-1R ligands (IGF-I and IGF-II) exists in series of cancers and contributes to the resistance in IGF-1R-targeted therapies. The IGF-I/II actions are mediated through the IGF receptor type 1 (IGF-1R) and the insulin receptor (IR), which are overexpressed in multiple types of tumors. Up to date, we have developed different antibody formats against IGF-II or IGF-I/II, including one fully human IgG m708.5 with picomolar affinity[1], two bispecific antibodies (BsAbs) m660 [2, 3] and m67 [4], and one small-size nanobody s7g1 (15 kDa) (unpublished data). BsAb m67 has exhibited in cynomolgus macaques and high stability in serum. Compared with large-size antibodies, nanobody s7g1 has distinct advantages because of greater and more rapid tissue accumulation. All antibodies can eliminate the efflux of IGFs from tumor tissues and circulating IGFs in the serum. The m708.5 shows dual-specific for IGF-I/IGF-II with the highest affinities. The m708.5 has shown satisfying preclinical activities against a broad spectrum of human cell lines. When tested in neuroblastoma cell lines, m708.5 showed strong antitumor activity alone and in combination with chemotherapeutic agents [5]. Therefore, the anti-IGF-I/II antibodies offers an alternative approach to target both the IGF-1R and IR-A signaling pathways through the inhibition of IGF-I/II. These results support the clinical development of anti-IGF antibodies for solid tumors with potential for synergy with chemotherapy. Acknowledgements: This work was supported by the Science and Technology Development Fund of Macau (FDCT/131/2016/A3). References: 1. Zhao, Q., et al.. Mol Cancer Ther, 2011. 10(9): p. 1677-85. 2. Chen, W., et al.. Mol Cancer Ther, 2012. 11(7): p. 1400-10. 3. Feng, Y., et al.. Mol Cancer Ther, 2009. 8(5): p. 1113-8. 4. Feng, Y., et al.. Exp Mol Pathol, 2014. 97(3): p. 359-67. 5. Zhao, Q., et al.. Int J Cancer, 2015. 137(9): p. 2243-52.
Citation Format: Qi Zhao. Monoclonal and bispecific antibodies against human insulin-like growth factors in oncology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3830.
Abstract 3835: Targeting loss of MTAP expression in glioblastoma multiforme with a combination of 2-fluoroadenine and methylthioadenosine
Authors: Tang Baiqing 
Published: August 2018

Abstract
Methylthioadenosine Phosphorylase (MTAP) is a key enzyme in the purine and methionine salvage pathways that convert the polyamine byproduct 5′-deoxy-5′-methylthioadenosine (MTA) into adenine and methylthioribose-1-phosphate. Homozygous deletion of the MTAP gene is observed in 55% of all glioblastoma multiforme (GBM) tumors. Since MTAP is a house-keeping enzyme found in all normal tissues, the lack of MTAP in GBM makes MTAP-loss a potential therapeutic target. In this study, we explore a novel strategy to target MTAP-loss in GBM by combining 2-fluoroadenine (2FA), a highly toxic adenine analogue, with MTA. Because MTAP is expressed in all normal tissues, MTA will be converted to adenine, which will protect against 2FA toxicity. However, in tumor cells, the effects of 2FA will not be ameliorated because they lack MTAP. Here we show that there is undetectable expression of MTAP in A172 and U87 GBM cell lines by both western blot and MTAP enzyme activity assays. In vitro toxicity studies in which cells were cultured with either 2FA alone or 2FA plus MTA revealed that both cell lines were sensitive to 2FA with or without MTA. The LD50 of A172 cells was 110 nM (2FA) and 127 nM (2FA + 5 μM MTA), while for U87 cells it was 397 nM (2FA) and 323 nM (2FA + 5 μM MTA). This is in sharp contrast to MTAP+ NIH3T3 cells in which we observed a 44 fold shift in the ratio of the LD50 concentration in the presence and absence of MTA (160 nM versus 7000 nM). Addition of MTA protected normal tissues against 2FA toxicity in SCID mice. SCID mice subcutaneously injected with either A172 or U87 cells and then treated with 2FA(10 mg/kg) + MTA(50 mg/kg) showed significantly reduced tumor growth
compared to vehicle treated controls. Our results indicated that 2FA+MTA might be effective in treating GBM.
Citation Format: Baiqing Tang. Targeting loss of MTAP expression in glioblastoma multiforme with a combination of 2-fluoroadenine and methylthioadenosine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3835.
Abstract 3841: Biologic evaluation of heterocyclic pyrimidines as novel tubulin inhibitors targeting the colchicine binding site
Authors: Arnst Kinsie 
Published: August 2018

Abstract
Interfering with tubulin dynamics is an attractive strategy for cancer therapy, and tubulin-targeting agents are some of the most widely used chemotherapeutic drugs. Current FDA-approved tubulin inhibitors target either the taxane site (e.g., paclitaxel) or the vinca alkaloid site (e.g., vinblastine). However, their clinical efficacy is often limited by the development of multidrug resistance and a narrow therapeutic index. Tubulin inhibitors interacting with the colchicine site have shown potent anticancer activities, are generally less susceptible to multidrug resistance, and can disrupt tumor vasculature, leading to rapid tumor cell apoptosis. Here, we report on the biologic evaluation of heterocyclic pyrimidines as a new class of tubulin inhibitors targeting the colchicine binding site with a significantly improved therapeutic index. One of the most promising compounds of the series, SB157, was able to strongly inhibit tubulin polymerization and induce cytotoxicity in cancer cells in vitro. We have also obtained the high-resolution X-ray crystal structure for SB157, confirming its direct binding to the colchicine binding site in tubulin, and elucidated the detailed molecular interactions. SB157 significantly inhibited tumor growth in an A375 melanoma xenograft model, and the tumors revealed elevated apoptotic activity and extensive disruption of tumor vasculature. Finally, we demonstrated that SB157 significantly overcame clinically relevant multidrug resistance in a paclitaxel-resistant PC-3/TxR prostate cancer xenograft mouse model. Collectively, these studies provide preclinical proof of concept and structural basis to support the continued development of SB157 and optimization of this scaffold as an improved class of tubulin inhibitors for cancer therapy.
Citation Format: Kinsie Arnst. Biologic evaluation of heterocyclic pyrimidines as novel tubulin inhibitors targeting the colchicine binding site [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3841.