bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract CT151: TTFields and radiosurgery for 1 to 10 brain metastases from NSCLC in the phase III METIS study
Authors: Mehta Minesh , Gondi Vinai , Ahluwalia Manmeet , Brown Paul D.
Published: August 2018

Tumor Treating Fields (TTFields) are non-invasive, loco-regional, anti-mitotic treatment modality, based on low intensity alternating electric fields. Efficacy of TTFields in non-small cell lung cancer (NSCLC) has been demonstrated in multiple in vitro and in vivo models, and in a phase I/II clinical study. TTFields treatment to the brain was safe and extended overall survival in newly-diagnosed glioblastoma patients.

The study [NCT02831959] objectives are to test the efficacy, safety and neurocognitive outcomes of TTFields in this patient population. Patients (N=270) with 1-10 brain metastases (BM) from NSCLC are randomized 1:1 to stereotactic radio surgery (SRS) followed by TTFields or supportive care. Patients are followed-up every two months until 2nd intracranial progression. Patients in the control arm may cross over to TTFields at the time of 2nd intracranial progression. Key inclusion criteria: KPS ≥70, 1 inoperable or 2-10 brain lesions amenable to SRS, optimal standard therapy for the extracranial disease, no brain-directed therapy, no signs of significantly increased intracranial pressure, and no electronic implantable devices in the brain. Endpoints included time to 1st intracranial progression or neurological death (primary); time to neurocognitive failure, HVLT, COWAT and TMT); overall survival; radiological response rate; quality-of-life; and adverse events. Treatment comprised continuous TTFields at 150 kHz for > 18 hours/day applied to the brain within 7 days of SRS. The treatment system is a portable medical device allowing normal daily activities. The device delivers TTFields to the brain using 4 Transducer Arrays, which may be covered by a wig or hat. Patients receive the best standard of care for their systemic disease. Statistical Considerations: This is a prospective, randomized, multicenter study. The sample size (N=270) was calculated using a log-rank test (Lakatos 1988 and 2002) with 80% power at a two sided alpha of 0.05 to detect a hazard ratio of 0.57.

Citation Format: Minesh Mehta, Vinai Gondi, Manmeet Ahluwalia,, Paul D. Brown. TTFields and radiosurgery for 1 to 10 brain metastases from NSCLC in the phase III METIS study [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 CT151.
Abstract CT155: Design of a dose escalation phase 1/2 trial for a novel combined cell and oncolytic viral therapy
Authors: Contag Pamela R.
Published: August 2018

Ovarian cancer is the sixth most common malignancy in women and the leading cause of death from all gynecological cancers in the United States with epithelial ovarian cancer are often diagnosed with advanced- stage disease. Although clinically complete remissions are obtained in the majority of patients through a combination of cyto-reductive surgery and chemotherapy, relapse is common with 70% of patients exhibiting recurring disease and thus represents a high unmet need. Single-agent therapies used to treat the subset of patients with chemotherapy- resistant/refractory ovarian cancer include paclitaxel, PLD (peglyated liposomal doxorubicin) and topotecan. The response rate is in the 10-15% range and overall survival is approximately 12 months. Our immunotherapy is comprised of cytokine-induced NK-T cells which stealthily delivers a tumor selective vaccinia virus to the tumor microenvironment, attracted by chemokines released by the tumor and binding to tumor stress ligands. The virus is released in the tumor site and is synchronously released to kill tumor cells, reducing or eradicating the tumor. This therapeutic approach is multi-mechanistic and delivery of the oncolytic agent by the immune effector cells together may result in a durable immune response to ovarian tumor- specific antigens through a cytotoxic T-cell mechanism. The two components, vaccinia virus vvDD-CDSR and CIK cells have been tested and investigated in multiple pre-clinical and clinical studies that have demonstrated their antitumor efficacy and overall safety. In our proposed Open Phase I/II clinical study will be a dose escalation to determine a MFD/MTD. The maximum-feasible dose (MFD) will be defined as the top dose level if no MTD is defined. It is expected that a maximum of 22 patients will be required to establish the MTD for one infusion. Once an MFD/and or MTD is determined, the study moves onto Phase II part of the protocol design allowing multiple cycles up to 4, treating 6-22 patients in Arm 1 safety and 20 patients in Arm 2 efficacy.

Citation Format: Pamela R. Contag. Design of a dose escalation phase 1/2 trial for a novel combined cell and oncolytic viral therapy [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 CT155.
Abstract DDT02-01: FAP-4-1BBL: A next generation, targeted costimulatory agonist for cancer immunotherapy
Authors: Umana Pablo
Published: August 2018

This talk will describe a new drug candidate for cancer immunotherapy, FAP-4-1BBL, a next generation, tissue-targeted agonist of the 4-1BB costimulatory receptor. Agonizing 4-1BB to enhance the activity of antitumor T cells has been successfully exploited by 2nd and 3rd generation CAR T-cell therapies for hematological malignancies. However, the clinical development of first-generation, 4-1BB agonistic antibodies for systemic administration has been hampered by significant hepatic toxicity. Here we describe a next generation, fibroblast activated protein (FAP)-targeted 4-1BB agonist whose activity is independent of Fc-gamma-receptor (FcγR)-binding, is safe in preclinical models (including non-human primates using doses of up to 50 mg/kg) and is significantly more potent and efficacious than first generation, standard 4-1BB agonistic antibodies when compared side-by-side in preclinical models. In preclinical models, combination of FAP-4-1BBL with T-cell bispecific antibodies leads to significant increases in T cell infiltration into the tumor, CD8/Treg ratio and anti-tumoral efficacy. We conclude that the tumor-targeted cross-linking of 4-1BB provides a safe and effective way for co-stimulation of T cells for cancer immunotherapy and its combination with T-cell bispecific antibodies may provide a convenient “off-the-shelf,” systemic cancer immunotherapy approach for many tumor types.

Citation Format: Pablo Umana. FAP-4-1BBL: A next generation, targeted costimulatory agonist for cancer immunotherapy [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 DDT02-01.
Abstract LB-001: Development and evaluation of T-Zap: a novel antibody-drug conjugate for the treatment of Her2 positive breast cancer
Authors: Hoffmann Ricarda M. , Crescioli Silvia , Thurston David E. , Karagiannis Sophia N.
Published: August 2018

Background:

Breast cancer is the most common type of cancer worldwide and HER2-overexpressing types are especially associated with poor prognosis. Antibody-drug conjugates (ADCs) have been developed as a targeted approach to deliver toxins to cancer cells specifically with the ADC trastuzumab-emtansine (T-DM1) already in clinical use. A novel ADC T-Zap has been developed by linking the antibody trastuzumab to saporin - a ribosome inactivating protein. This study aims to evaluate the novel ADC T-Zap for the treatment of HER2 positive breast cancer.

Methods:

The plant toxin saporin was linked to the monoclonal antibody tratuzumab via a streptavidin-biotin bridge. Binding kinetics were assessed using flow cytometry, and MTS cell viability assays were performed to compare efficacy to T-DM1. Toxicity towards immune cells was investigated by MTS assays using immune cells.

Results:

Binding to target cells of T-Zap was confirmed. Comparison of T-Zap efficacy in breast cancer cell lines with and without resistance against trastuzumab showed a trend for higher efficacy of cell killing by T-Zap in trastuzumab resistant cells compared to T-DM1. Toxicity assays revealed no impact of T-Zap on cell viability in immune cells.

Conclusions:

Cell viability caused by T-Zap was more efficient compared to T-DM1 in the trastuzumab resistant cell line HCC1945. This strengthens the hyposthesis that T-Zap might have potential as new ADC overcoming trastuzumab resistance. Future work will include the development of a specific linker to link trastuzumab to saporin with the aim to develop an ADC that could prove a novel therapeutic agent for the treatment of HER2 positive breast cancer.

Citation Format: Ricarda M. Hoffmann, Silvia Crescioli, David E. Thurston, Sophia N. Karagiannis. Development and evaluation of T-Zap: a novel antibody-drug conjugate for the treatment of Her2 positive breast cancer [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 LB-001.
Abstract LB-019: Empowering preclinical studies: A systematic and quantitative analysis of biodistribution methods to facilitate clinical translation of new drugs
Authors: Nizzero Sara , Li Feng , Venuta Alessandro , Zhang Guodong , Borsoi Carlotta , Wolfram Joy , Mai Junhua , Shen Haifa , Li Zheng , Blanco Elvin , Ferrari Mauro
Published: August 2018

Biodistribution detection methods currently hold a central role in evaluating clinical potential of new drugs and nanomedicine in vivo, either through therapeutic efficacy or toxicity assays. However, the explorative nature of these methods makes it practically difficult to validate them for clinical studies to comply with regulations as determined by the Food and Drug Administration. This work proposes a new systematic comparison of biodistribution methods to facilitate clinical validation and employment in pre-clinical and early stage clinical studies. Several optical methods (detection through IVIS, confocal microscopy, fluorescence emission), direct detection methods (detection through ICP-OES), and radiation-based methods (detection through gamma counter) are systematically tested and validated on cGMP grade microparticles. The classification here proposed quantitatively highlights the advantages and disadvantages of each method, expressing them in terms of: limit of detection, recovery rate, reproducibility, and sensitivity. As a result, this quantitative evaluation of several preclinical biodistribution detection methods leads to a new rational and objective classification of biodistribution methods based on quantitative characteristics, which is essential to facilitate clinical translation of pre-clinical data collection. Their different characteristics and application-specific advantages are also discussed based in light of the results presented. Overall, this work proposes a new and rational quantitative comparison of biodistribution detection methods with the goal to provide a guide to facilitate clinical translation of on-going and future pre-clinical and early-stage clinical studies.

Citation Format: Sara Nizzero, Feng Li, Alessandro Venuta, Guodong Zhang, Carlotta Borsoi, Joy Wolfram, Junhua Mai, Haifa Shen, Zheng Li, Elvin Blanco, Mauro Ferrari. Empowering preclinical studies: A systematic and quantitative analysis of biodistribution methods to facilitate clinical translation of new drugs [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 LB-019.
Abstract LB-024: The effects of chromatin structure on variation in fragment size of cell free DNA
Authors: Xia Hui , Li Xingya , Bao Hua , Ma Xiangyuan , Wu Xue , Shao Yang W. , Wu Feixiang , Zhang Shucai
Published: August 2018

Liquid biopsy using cell-free DNA (cfDNA) has established its clinical utilities in multiple clinical cohorts. However, the exact mechanism by which cell-free DNA (cfDNA) is generated remains undetermined. The fragment size of cfDNA sheds important insights on elucidating the process. Previous studies qualitatively concluded that tumor-derived cfDNA is shorter than cfDNA from healthy cells, but the exact size distribution of tumor-derived cfDNA remains unclear. To better understand the mechanism of cfDNA generation and directly study cfDNA of tumor origins, we analyzed the deep targeted sequencing results of cfDNA from 605 patients with various cancer types, and developed a method that separates tumor cfDNA through identification of somatic variant alleles-containing fragments. We show that tumor-derived cfDNA has an increased proportion of fragments less than 150bp compared to healthy controls, while the most common size is still 166 bp. It has been speculated that differences in nucleosome wrapping may contribute to differing fragment lengths of cfDNA.To better understand the relationship between the magnitude of chromatin packaging and cfDNA length, we quantitatively analyzed the size distribution of cfDNA collected from 5 cancer patients in genomic regions with the varying degree of chromatin openness. We discovered that the fragment size of cfDNA was closely associated with chromatin inaccessibility and chromosome condensation as measured by transcriptional start sites, DNase I hypersensitivity, histone modifications, and Giemsa banding, or as implied by chromosomal sub-nuclear localization. The shortening occurs at both 5' and 3' ends of cfDNA fragments without bias. Taken together, these results collectively established a positive correlation between cfDNA fragment size and chromatin inaccessibility.

Citation Format: Hui Xia, Xingya Li, Hua Bao, Xiangyuan Ma, Xue Wu, Yang W. Shao, Feixiang Wu, Shucai Zhang. The effects of chromatin structure on variation in fragment size of cell free DNA [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 LB-024.
Abstract LB-037: 3D organoids from milligrams of genitourinary cancer patients tissue retain key features of original tumors
Authors: Wang Yue , Souza Glauco , Amato Robert J.
Published: August 2018

3D organoid culture, especially that generated from patient samples, is becoming prevalent as 2D cell culture models fail to provide clinical relevance. However, a relatively large amount of starting tissue is still required for this process, and the turnover rate and overall success rate vary greatly if relying solely on spontaneous aggregation. Here, we report the successful use of magnetic 3D bioprinting to drive organoid formation derived from fresh tumor samples of patients with prostate cancer, renal cell cancer, and urothelial cancer. Only milligrams to tens of milligrams of starting tissues (from fine-needle biopsies, core biopsies, or surgical excision) were used. Most organoids formed overnight, with a very high overall success rate (>95%, n = 25). We have demonstrated that these cultures can be maintained, passed, and cryopreserved like conventional 2D cultures. More importantly, we characterized the organoids derived from prostatic adenocarcinomas and neuroendocrine tumors by the means of immunostaining and showed that the organoids expressed the same signature proteins as the originating tumors. This clinical concordance is crucial for downstream translational and biological research. We also showed that these adenocarcinoma cells responded to enzalutamide, an androgen receptor inhibitor that is used clinically to treat prostatic adenocarcinoma. In summary, we have established an efficient and robust system to create patient-derived 3D organoids; molecular characterization shows clinical concordance with original patient tumors; and our system shows great potential in drug screening with patient-derived 3D cultures.

Citation Format: Yue Wang, Glauco Souza, Robert J. Amato. 3D organoids from milligrams of genitourinary cancer patients tissue retain key features of original tumors [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 LB-037.
Abstract LB-057: Hypoxia regulation of antigen presentation machinery expression in breast cancer
Authors: Ng Mei Rosa , Sabbatino Francesco , Duquette Mark , Naxerova Kamila , Badeaux Mark , Ferraro Gino B. , Chin Shan M. , Bezwada Divya , Brachtel Elena F. , Ferrone Soldano , Jain Rakesh K.
Published: August 2018

Antigen presentation plays a major role in tumor cell recognition and targeting by immune cells, and is critical to the success of many cancer immunotherapies. How the abnormal tumor microenvironment affects tumor cell antigen presentation is unclear. Hypoxia is a prevalent feature of the tumor microenvironment. Here, we showed that the expression of major histocompatibility complex class I (MHCI) is associated with regions of hypoxia in human breast tumors. The association between hypoxia and MHCI is independent of the breast tumor hormone receptor and HER2 expression status. In vitro studies revealed that hypoxia directly regulates the expression levels of MHCI along with other components of the antigen presentation machinery. Multiple kinase regulators of MHCI expression are responsive to hypoxia. These results suggest that hypoxia effects on cancer cell antigen presentation may be a potential mechanism of tumor immune evasion and treatment resistance.

Citation Format: Mei Rosa Ng, Francesco Sabbatino, Mark Duquette, Kamila Naxerova, Mark Badeaux, Gino B. Ferraro, Shan M. Chin, Divya Bezwada, Elena F. Brachtel, Soldano Ferrone, Rakesh K. Jain. Hypoxia regulation of antigen presentation machinery expression in breast cancer [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 LB-057.
Abstract LB-063: Phospholipid drug conjugates show specificity for a broad range of tumor cells and provides a novel approach for targeted or precision therapy
Authors: Longcor Jarrod , Banach Maria , Hoover Randall
Published: August 2018

The majority of anticancer drugs in clinical use have their utility limited by their toxicity to all proliferating cells, including normal cells and the inability to exert their effect on all of the tumor cells. Novel cytotoxic agents continue to be developed with unique mechanisms of action meant to provide increased targeting, however, many of these compounds still lack absolute tumor selectivity and continue to be limited in their therapeutic utilization due to off-target effects. Antibody drug conjugates (ADCs) have been design to bind to specific epitopes on the surface of tumor cells and have offered an alternative method to target tumor cells in an effort to reduce associated toxicities. Although highly selective, very few antibody drug conjugates are therapeutically useful since they only achieve modest cellular uptake and limited cell killing activity. Here we describe the development of a novel targeting platform using phospholipid ether (PLE) molecules to provide tumor cell specific targeting. These molecules known as phospholipid drug conjugates (PDCs) show high specificity for tumor cells; 6 to 30-fold increase in targeting tumor cells over normal tissue, result in up to 20% of exposed compound entering in to the tumor cells (as compared to < 1% of an ADC), and show a range of compounds can be conjugated to them. We have tested the uptake of our PDCs across over 80 different tumor cell lines and have shown consistent preferential uptake by tumor cells versus normal cells even when in co-culture. This could result in an improvement of the therapeutic index for many compounds.

Citation Format: Jarrod Longcor, Maria Banach, Randall Hoover. Phospholipid drug conjugates show specificity for a broad range of tumor cells and provides a novel approach for targeted or precision therapy [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 LB-063.
Abstract LB-074: Examining SENP Localization In HEK-293 Cells Using MG-132 And Cycloheximide
Authors: Robinson Michael , Umbaugh Charles S. , Figueiredo Marxa L.
Published: August 2018

Post translational modifications are changes to proteins that occur during or after synthesis by the ribosome. Often these modifications are necessary to form mature proteins. SUMOylation (Small Ubiquitin-like Modifier, SUMO) is a type of post translational modification that has a connection to a protein, Laminin Receptor, that contributes to the aggressiveness and proliferation of cancer.

SUMO proteases, called SENPs, remove SUMO groups from SUMOylated proteins. Because Laminin Receptor may be a SUMOylated protein and is in the nucleus, we wanted to first explore how SENP-2 and SENP-3 localize under various cellular conditions. To understand the behavior of SENPs under cellular stress, we transfected human embryonic kidney cells, called HEK-293 cells, with SENP-2 or SENP-3 tagged to the fluorescent protein EGFP. We treated the cells with MG-132, a proteasome inhibitor, or with cycloheximide, a protein synthesis inhibitor. We used live imaging to qualitatively understand how SENP-2 and SENP-3 localize in the cell in normal conditions and under cell stress. Then, we looked for differences in cytosolic and nuclear partitioning of SENP-2 and SENP-3 by western blot. The exposure of SENPs to the two inhibitors helped us to understand the behavior of the SUMO proteases between the nucleus and cytoplasm.

Citation Format: Michael Robinson, Charles S. Umbaugh, Marxa L. Figueiredo. Examining SENP Localization In HEK-293 Cells Using MG-132 And Cycloheximide [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 LB-074.
Abstract LB-079: The interaction of MSI1 and AGO2 promotes glioblastoma multiforme progression under environmental stress
Authors: Chen Hsiao-yun , Chiou Shih-Hwa
Published: August 2018

Glioblastoma multiforme (GBM) is the high-grade astrocytoma; it is the most common and aggressive malignant brain tumor. GBM is largely resistant to therapy and experiences a corresponding poor prognosis. Therefore, GBM progression and recurrence are the main therapeutic challenges frequently faced by patients with refractory tumors. Nevertheless, the underlined molecular mechanism remains unknown. The RNA-binding protein musashi1 (MSI1) is expressed in stem cell compartments and in the aggressive tumor, only little is known about its function and mechanism in fact decision of target mRNA and post-transcription control. In this study, we describe a mechanism by which stress induces tumor progression via elevated cytoplasmic translocation of MSI1 in malignant neoplasms. MSI1 forms ribonucleoprotein (RNP) complexes with its downstream mRNAs at the 3'-untranslated region (3'UTR) or coding domain sequence (CDS) in the nucleus. Upon stress conditions, the MSI1/mRNA complex translocates to the cytosol where Argonaute2 (AGO2) is recruited and directly interact with MSI1. The MSI1/AGO2 complex modulates mRNA stability depending on their binding locations on the mRNA targets. Blocking of MSI1 shuttling by either a nuclear export inhibitor (Leptomycin B, LMB) or NES/NLS mutant attenuates GBM tumor growth in the mouse model. Importantly, the MSI1-AGO2 complex enhances GBM cells proliferation and survival under stress stimulation. MSI1 directly binds to AGO2 in the cytosol through its C-terminus. Orthotopic delivery of MSI1-C-terminus decoy peptides, which disrupt the MSI1/AGO2 interaction, effectively reduces stress-induced tumor progression. These results provide new insights into the function of MSI1 and suggest a novel peptide-based therapeutic strategy against refractory malignancies.

Citation Format: Hsiao-yun Chen, Shih-Hwa Chiou. The interaction of MSI1 and AGO2 promotes glioblastoma multiforme progression under environmental stress [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 LB-079.
Abstract LB-088: Cytokine-transgenic NOG mice engrafted with human peripheral blood cells support natural killer cell expansion
Authors: Volden Paul
Published: August 2018

Harnessing natural killer (NK) cells and their ability to mediate antibody-dependent cellular cytotoxicity (ADCC) forms the basis for many ongoing immuno-oncology efforts. Currently, most preclinical in vivo studies of ADCC-dependent efficacy rely on syngeneic models, which mandate the generation and use of surrogate therapies to overcome differences between mouse and human immune systems. These steps add time and cost, and can be particularly challenging for advanced antibody therapeutics (e.g. bispecific antibodies and antibody-drug conjugates). A humanized immune system (HIS) model that supports human NK cells could improve evaluations of human NK cell-dependent cancer therapies. However, HIS models have largely failed to support human NK cell-engraftment, rendering them inadequate for ADCC studies. Prior work has shown that human cytokine-transgenic hIL2-NOG and hIL15-NOG mice support the development of human NK cells from engrafted human hematopoietic stem cells (HSCs). Furthermore, the hIL15-NOG model has been shown to support in vivo expansion and long-term engraftment of isolated human NK cells. These properties suggest hIL2-NOG and/or hIL15-NOG might also sufficiently support NK cells following engraftment of peripheral blood mononuclear cells (PBMCs). Such a model could enable cost-effective and efficient in vivo studies of human NK cells and therapeutic human antibodies. To test this hypothesis, NOG, hIL-2 NOG, and hIL-15 NOG mice were engrafted with PBMCs from a single donor and at one of three increasing cell doses. The onset of graft vs host disease and peripheral blood human immune cell subsets were monitored through the duration of this study. Results showed that hIL15-NOG mice had a slightly diminished survival compared to conventional NOG. Nevertheless, hIL15-NOG survived up to 7 weeks after PBMC engraftment without any signs of graft vs host disease. Although hIL2-NOG mice showed the best engraftment rate for NK cells and other immune cell subpopulations, the overall survival was severely decreased post engraftment. Comparing NK cell-engraftment in hIL15-NOG and conventional NOG mice, we observed a tenfold increase of NK cell numbers in hIL15-NOG mice, independent of engrafted PBMC numbers, making it a highly suitable HIS model for studying NK cells.

Citation Format: Paul Volden. Cytokine-transgenic NOG mice engrafted with human peripheral blood cells support natural killer cell expansion [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 LB-088.
Abstract LB-089: Targeting WNT signaling in vivovia Tankyrase inhibition
Authors: Schatoff Emma M. , Leach Benjamin I. , Foronda Miguel , Zafra Maria Paz , Goswami Sukanya , Dow Lukas E.
Published: August 2018

Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States. Approximately 95% of CRCs show hyperactive WNT signaling, yet there are no targeted therapies that effectively suppress the WNT pathway. The majority (~80%) of these tumors harbor a mutation in APC, a scaffold component of the ‘destruction complex', which is a critical negative regulator of WNT. Using genetically defined mouse models of CRC, we recently showed that restoring Apc function can induce WNT suppression, and rapid and sustained disease regression. While there is no way to restore normal APC protein in human CRCs, it may be possible to restore the function of the APC-associated destruction complex by inhibiting Tankyrase (TNKS) enzymes. Tankyrase inhibitors have been shown to stabilize AXIN, prevent degradation of the destruction complex, and decrease levels of WNT signaling. While in vitro studies have shown promise, it is unclear whether TNKS inhibition could provide a therapeutic benefit in vivo. Some published work reports significant anti-tumor activity, while others suggest overt dose-limiting toxicity. Thus, while TNKS inhibition holds significant potential, it is not clear whether TNKS enzymes are a viable target for CRC therapy. To circumvent the limitations of drug delivery, potency, and specificity, we generated mice with inducible, fluorescent reporter-linked shRNAs targeting Tnks and its redundant family member Tnks2. Here we show that potent, simultaneous shRNA-mediated knockdown of both genes is sufficient to stabilize Axin in vivo, similar to treatment with a pan-TNKS inhibitor, XAV939. We show that Tnks1/2 knockdown stabilizes Axin, suppresses WNT signaling, and blocks hyperproliferation driven by Apc loss. In contrast to current studies using small molecule TNKS inhibitors, our work suggests that there is a viable therapeutic window of TNKS1/2 inhibition in vivo, and that this strategy enables control of hyperactive WNT signaling in CRC and other WNT-associated cancers.

Citation Format: Emma M. Schatoff, Benjamin I. Leach, Miguel Foronda, Maria Paz Zafra, Sukanya Goswami, Lukas E. Dow. Targeting WNT signaling in vivovia Tankyrase inhibition [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 LB-089.
Abstract LB-091: Hedgehog signaling induces drug resistance in gastric cancer cells via upregulation of ABCG2
Authors: YU BEIQIN , GU DONGSHENG , ZHANG XIAOLI , LIU BINGYA , XIE JINGWU
Published: August 2018

Gastric cancer is the third leading cause of cancer-related mortality worldwide. Currently, there are no specific therapeutic options to cure gastric cancer, and chemotherapy is frequently used. Some patients respond initially to chemotherapy but all patients eventually succumb to the disease. Thus, identifying molecular mechanisms responsible for chemotherapy resistance may help design novel strategies to sensitize cancer cells to chemotherapy. In this study, we revealed that treatment with chemotherapeutic reagents CDDP and 5Fu induced expression of GLI1, GLI2 and PTCH1 in gastric cancer cell lines, suggestive of hedgehog (Hh) signaling activation. GLI1 knockdown sensitized gastric cancer cells to CDDP and 5Fu treatment whereas ectopic GLI1 expression desensitized cancer cells to these treatments. Further analyses indicate elevated Hh signaling is associated with an increase in putative cancer stem cell marker expression, such as ABCG2. We found that GLI1 protein binds to the promoter of ABCG2 through a Gli-binding consensus site. Disruption of ABCG2 function, through ectopic expression of an ABCG2 dominant negative construct or a specific ABCG2 inhibitor, resulted in an increase of drug sensitivity both in culture and in mice. The relevance of our studies to gastric cancer patient care is reflected by our discovery that high ABCG2 expression was associated with poor survival in the gastric cancer patients who underwent chemotherapy. Taken together, we have identified a molecular mechanism by which gastric cancer cells gain chemotherapy resistance.

Citation Format: BEIQIN YU, DONGSHENG GU, XIAOLI ZHANG, BINGYA LIU, JINGWU XIE. Hedgehog signaling induces drug resistance in gastric cancer cells via upregulation of ABCG2 [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 LB-091.
Abstract LB-107: Repurposing endogenous immune pathways to improve chimeric antigen receptor T-cells potency
Authors: Sachdeva Mohit , Busser Brian , Temburni Sonal , Juillerat Alexandre , Poirot Laurent , Duchateau Philippe , Valton Julien
Published: August 2018

CAR T-cell therapies hold great promise for treating a range of liquid malignancies but are however challenged to access and eradicate solid tumors. To overcome this hurdle, CAR T-cell were engineered to secrete different cytokines known to improve T-cell antitumor activity, prevent T-cell anergy and reduce activation induced cell death. While cytokine-expressing CAR T-cell were shown to be be highly active against solid tumor in in vivo models, they have also led to toxicity associated with the systemic release of cytokine. Therefore, new engineering strategies enabling the fine tuning of cytokine secretion by CAR T-cell are warranted. We sought to explore one of these engineering strategies by integrating an IL-12 chimeric heterodimer expression cassette under the control of the endogenous promoters regulating PD1 or CD25. Because both genes are known to be activated upon tumor engagement by CAR T-cells, they could be repurposed to secrete cytokine only in the vicinity of a given tumor. This approach would reduce the potential side effects induced by their systemic secretion while maintaining their capacity to improve antitumor activity. By combining TALEN® technology with AAV6 repair vectors delivering the CAR to the TRAC locus and the IL-12 to the CD25 or PD1 loci, we have engineered CAR and IL-12 expressions under the respective control of TCR and CD25 or PD1 regulatory elements. This double targeted insertion led to the disruption of PD1 and TRAC genes, to the expression of a tool CAR and to the conditional secretion of IL-12 in the media. Such secretion was found to be transient, dependent on tumor engagement and to follow the regulation patterns of CD25 or PD1 genes, commonly observed upon T-cell activation. In addition, it was also found to enhance the antitumor activity and the proliferative capacities of CAR T-cells. Similar results were obtained when IL-15 was substituted for IL-12. This proof of concept paves the way for seamless multi-repurposing of immune pathways to generate smarter CAR T-cells able to sense and react to their environment in a highly regulated and specific manner.

Citation Format: Mohit Sachdeva, Brian Busser, Sonal Temburni, Alexandre Juillerat, Laurent Poirot, Philippe Duchateau, Julien Valton. Repurposing endogenous immune pathways to improve chimeric antigen receptor T-cells potency [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 LB-107.
Abstract LB-113: Enhanced anti-tumor efficacy of CEACAM1-targeting antibody after affinity maturation
Authors: Eun So-Young , Lee Mijung , Park Hye-Young , Oh Miyoung , Yum Hye In , Yoon Aerin , Lee Eunhee , Nam Hyemi , Yun Sungtae , Cho Hyunjung , Hur Minkyu , Kim Jaehwan , Cho Byoung Chul , Won Jonghwa
Published: August 2018

Since the huge success of PD-1 blocking antibodies in clinical studies, anti-cancer therapy has changed its strategic gear to immunotherapy, which showed the strongest potential to eradicate cancer without detrimental side effects. Antibodies targeting similar immune checkpoint proteins with immunosuppressive functions have started to surge into clinical trials. CEACAM1 (CCM1) is also a potential target for anti-cancer immunotherapy because it is an ITIM-containing inhibitory molecule expressed on activated T cells and NK cells, on which it suppresses T/NK cell-mediated pro-inflammatory immune responses. CCM1-CCM1 homophilic interaction inhibits ZAP-70 phosphorylation in the TCR proximal signaling complex, thereby suppressing T cell activation. The anti-cancer therapeutic potential of CCM1-blockade has already been demonstrated in mouse models and one of the anti-human CCM1 antibodies entered into a phase I clinical trial once. As previously reported, our clone C25 (an anti-CCM1 monoclonal antibody) activated T cells and enhanced T/NK cell-mediated tumor cell-killing in a CCM1-dependent manner. The clone C25 was further engineered to have higher efficacies through mutagenesis within the variable regions of heavy and light chains. Here, we describe mutated variants of C25 with improved in vitro tumor-killing efficacies as well as higher binding affinities while maintaining fundamental characteristics of their parental clone C25. Most importantly, C25 and its variants exclusively bind to CCM1, but not to any other homologs of the CCM family. Such strong target-specificity will be a crucial point that distinguishes our clones from the other anti-CCM1 antibodies having off-target binding activities. We are currently investigating the CCM1-dependent anti-cancer therapeutic efficacy of our final clone on the patient-derived tumor xenografts implanted in a humanized mouse model. The target-ligand expression profiling on tumor tissues from lung cancer patients revealed strong clues for patient selection criteria and co-treatment options.

Citation Format: So-Young Eun, Mijung Lee, Hye-Young Park, Miyoung Oh, Hye In Yum, Aerin Yoon, Eunhee Lee, Hyemi Nam, Sungtae Yun, Hyunjung Cho, Minkyu Hur, Jaehwan Kim, Byoung Chul Cho, Jonghwa Won. Enhanced anti-tumor efficacy of CEACAM1-targeting antibody after affinity maturation [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 LB-113.
Abstract LB-115: Tumor intrinsic PD-1/PD-L1 signalling induces mesenchymal to epithelial transition in canine osteosarcoma cells
Authors: Parys Maciej , Nekulová Marta , Vojtěšek Bořivoj , Faktor Jakub , Lima Ana , Hupp Theodore
Published: August 2018

Osteosarcoma (OS) is the most common primary tumor of the bone in both humans and dogs. The dog, with its spontaneously occurring OS, shared pathogenic pathways and active immune system is one of the best models for studying novel immunotherapeutic approaches to human OS. Checkpoint blockade using antibodies against PD-1 has revolutionized the current approach to treatment of melanoma and other cancers. Recent reports have also shown that tumor intrinsic signalling plays a potential role in the success of PD-1 blockade in melanoma although studies in OS have not been published to date. PD-1/PD-L1 signalling has been reported to have role in epithelial to mesenchymal transition. In this study, we wanted to characterize intrinsic PD-1 signalling in canine osteosarcoma. We have created a canine specific PD-1 monoclonal antibody and we identified that PD-1 is intrinsically expressed in the cell line tested- OSA31. To further characterize the effects of PD-1 expression in this cell line we cloned canine PD-1 into a pcDNA 3.1 expression vector and transfected the cell line. Transfection of the cell line with PD-1 resulted in phenotypic changes characteristic for mesenchymal to epithelial transition. Interestingly overexpression of PD-1 as well as blockade of this receptor using the created antibody, resulted in decrease in cellular proliferation. To our knowledge this is the first report to identify role of PD-1 in mesenchymal to epithelial transition. These findings also suggest that PD-1 may be a promising therapeutic target in canine OS and warrant future clinical trials.

Citation Format: Maciej Parys, Marta Nekulová, Bořivoj Vojtěšek, Jakub Faktor, Ana Lima, Theodore Hupp. Tumor intrinsic PD-1/PD-L1 signalling induces mesenchymal to epithelial transition in canine osteosarcoma cells [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 LB-115.
Abstract LB-135: Biomarker utility of the E2/E6 ratio and L1 immunoreactivity for determining HPV16-positive ≥CIN2 lesions and cervical squamous cell carcinoma
Authors: Choi Youn Jin , Lee Sung-Jong
Published: August 2018

Objectives: Human papillomavirus (HPV)16 is the most carcinogenic HPV genotype. The objective of this study was to identify whether expression of the HPV16 L1 capsid protein and the E2/E6 ratio—both determined by cervical cytology—could be used as biomarkers of cervical pre-malignancy and cancer.

Methods: Cervical specimens were obtained from 226 patients with HPV16 single infection at Seoul St. Mary's Hospital. A Cytoactiv®HPV L1 screening set was prepared to detect the L1 capsid protein, and real-time polymerase chain reaction (PCR) was performed to determine the E2/E6 ratio of HPV16 DNA. Cytology results then were compared to results of conventional histologic analysis of cervical tissues (cervical intraepithelial neoplasia [CIN]1-3 and squamous cell carcinoma [SCC]) to evaluate the association.

Results: We found that the mean E2/E6 ratios of specimens graded as SCC (0.355) and of those graded as CIN2/3 (0.481) were significantly lower than the mean E2/E6 ratios for specimens graded as CIN1 (0.736) and those regarded as normal (0.792) (P < 0.05). Cytologic detection of HPV L1 enabled prediction of ≥CIN2 cervical lesions and differentiation of CIN2/3 from SCC (P < 0.05). Based on findings expressed as area under the receiver operating characteristic curve (AUC), the combination of HPV L1 immunohistochemistry and the E2/E6 ratio predicted ≥CIN2 cervical lesions (AUC, 0.871; 95% confidence interval, 0.826-0.917) better than either individual test.

Conclusions: To our knowledge, this study is the first to validate the expression of the HPV L1 capsid protein and a decreased HPV E2/E6 ratio as valuable predictive markers of ≥CIN2 cervical lesions, thereby discriminating cervical pre-malignancy and cancer. Cervical cytology can be analyzed on an outpatient basis with noninvasive procedures, in contrast to conventional histologic analysis, which is invasive. Moreover, cervical cytology can be conducted longitudinally to evaluate disease progression/regression without repeated invasive procedures.

Citation Format: Youn Jin Choi, Sung-Jong Lee. Biomarker utility of the E2/E6 ratio and L1 immunoreactivity for determining HPV16-positive ≥CIN2 lesions and cervical squamous cell carcinoma [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 LB-135.
Abstract LB-166: Antibiotic prescriptions and colorectal cancer recurrence risk: A Danish nationwide prospective cohort study
Authors: Fedirko Veronika , Cronin-Fenton Deirdre , Riis Anders Hammerich , Sørensen Henrik Toft , Andersen Claus Lindbjerg , Thorlacius-Ussing Ole , Lash Timothy
Published: August 2018

The large number of colorectal cancer survivors, coupled with the financial burden of colorectal cancer, makes it critical to identify factors associated with cancer recurrence. The human gut microbiome is one of the most densely populated bacterial communities known to exist. It plays a vital role in the host's gut physiology and potentially contributes to colorectal cancer progression. Given the prevalence and often overuse of antibiotics in the population, and their effects on the gut microbiome, the potential influence of antibiotics on the clinical course of colorectal cancer is of great public health importance. Using data from Danish medical registries, we followed 21,152 patients (5,036 with recurrences) diagnosed with stage I-III colorectal cancer from 2001 to 2011. We examined the association between pre- and post-diagnostic antibiotic use and cancer recurrence. After adjustment for potential confounders (age at diagnosis, sex, year of diagnosis, stage, tumor location, cancer treatment, comorbidities, inflammatory bowel disease, and use of statins, non-steroidal anti-inflammatory drugs and aspirin), any antibiotic prescription 90 days prior to colorectal cancer diagnosis was not associated with recurrence [adjusted hazard ratio (aHR) = 1.06, 95% confidence interval (CI): 0.98, 1.14]. However, antibiotic use after cancer diagnosis was associated with a higher risk of recurrence (aHR = 1.23, 95% CI: 1.16, 1.31). Additional ongoing analyses address cancer-specific and all-cause mortality and different time-lag periods. Their results also will be presented at the meeting. Our preliminary findings support further investigation into the possible roles of the gut microbiome and agents that alter its composition and diversity in colorectal cancer progression.

Citation Format: Veronika Fedirko, Deirdre Cronin-Fenton, Anders Hammerich Riis, Henrik Toft Sørensen, Claus Lindbjerg Andersen, Ole Thorlacius-Ussing, Timothy Lash. Antibiotic prescriptions and colorectal cancer recurrence risk: A Danish nationwide prospective cohort study [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 LB-166.
Abstract LB-171: Potential chemopreventative treatments in Fanconi anemia related HNSCC
Authors: Miller Kimberly A. , Wuertz Beverly R. , Haynes Anna M. , Potter David A. , Ondrey Frank G.
Published: August 2018

Fanconi anemia (FA) is a DNA repair mechanism genetic disorder which leads to bone marrow failure and cancer. Risk of solid tumor malignancy in FA patients occurs decades earlier and at a rate several hundred-fold higher than the general population, necessitating regular cancer surveillance. Development of an adjunct therapy or preventative survival-enhancing therapy with a minimal side effect profile will benefit this population in which chemotherapy and radiation are particularly damaging. To this end, we established a cell line from a post bone marrow transplant FA patient with a T2N2bM0 oral SCC grown as an adherent monolayer culture. We tested pioglitazone, metformin, and N1-hexyl-N5-benzyl-biguanide (HBB), emerging chemopreventative therapies for head and neck squamous carcinoma, for growth inhibition in head and neck cancer cell lines, including our FA SCC cell line. Additional cell lines include UMSCC 11A (laryngeal squamous cell carcinoma), CA 9-22 (oral squamous cell carcinoma), Beas2B (SV40 immortalized normal bronchial epithelium), and MSK Leuk1 (oral leukoplakia cell line). All cell lines are HPV negative. MTT assays determined cell viability after 1, 2, and 3 days of treatment. Pioglitazone at all concentrations (5, 10, 20, 40 μM) decreases cell proliferation compared to solvent controls (P<0.0001). Metformin (1 μM - 1 mM) unexpectedly increased cell proliferation or was otherwise equal in growth with the controls, and at higher doses (10 mM - 100 mM) metformin decreased cell proliferation or resulted in cytotoxicity (P<0.0001). Pioglitazone (10 μM) and metformin (above 1 mM) resulted in larger, cell line dependent, decreases in cell proliferation than either agent alone. In the FA cell line, pioglitazone and HBB resulted in increased efficacy. HBB treatment resulted in decreases in proliferation and percent live cells at 20 μM equivalent to the effect of 10 to 100 mM metformin. Combining HBB with 10 μM pioglitazone decreased cell proliferation and percent live cells over pioglitazone alone. HBB also caused S phase blockade in a pilot FA cell cycle experiment. Pioglitazone combined with HBB appears to be a promising chemopreventative adjunct treatment for HNSCC in FA patients. Further studies are underway to evaluate the relative contribution of HBB to decreased cell proliferation versus apoptotic mechanisms. Recent studies of HBB in breast cancer indicate cytochrome P450 arachidonic acid epoxygenase activity as an HBB target and suggest further exploration of this target in head and neck squamous cell carcinoma.

Citation Format: Kimberly A. Miller, Beverly R. Wuertz, Anna M. Haynes, David A. Potter, Frank G. Ondrey. Potential chemopreventative treatments in Fanconi anemia related HNSCC [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 LB-171.