bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 923: Pulsatile MEK inhibition improves anti-tumor immunity and T cell function in Kras mutant lung cancer
Authors: Choi Hyejin , Deng Jiehui , Li Shuai , Silk Tarik , Dong Lauren , Brea Elliott J. , Houghton Sean , Redmond David , Zhong Hong , Boiarsky Jonathan , Akbay Esra A. , Smith Paul D. , Merghoub Taha , Wong Kwok-Kin , Wolchok Jedd D. 
Published: September 2020

Abstract
KRAS is one of the most commonly identified driver oncogenes in non-small cell lung cancer (NSCLC) and is frequently associated with disease refractory to currently available modalities of treatment. Targeted therapy to inhibit MEK signaling has shown promising tumor growth control in preclinical models, but is followed by quick rebound in tumor growth. Recently, immune checkpoint blockade has demonstrated clinical activity by dis-inhibiting T cells suppressed in the tumor microenvironment. Thus, we sought to identify the most effective therapy for the treatment of KRAS mutant NSCLC patients by targeting cancer cells and activating immune infiltrating cell populations concurrently. To achieve this, we focused on studying the impact of pulsatile MEK inhibition on the immune microenvironment utilizing Kras mutant lung cancer cell lines and Kras mutant transgenic lung cancer mouse models. We found that pulsatile MEK inhibition maintained T cell activation better than continuous treatment ex vivo and in vivo. Treatment with two different MEK inhibitors (selumetinib and trametinib) each resulted in higher CTLA-4 and PD-1 expression in T cells using pulsatile treatment, compared to continuous treatment ex vivo. In addition, the pulsatile schedule showed superior anti-tumor effects and delayed drug resistance compared to continuous administration in vivo. Further, a combination of pulsatile MEK inhibitor treatment and CTLA-4 blockade resulted in the most prolonged survival of Kras tumor-bearing mice. Similar experiments in immune-deficient mice confirmed that this prolonged survival is conferred by adaptive immunity. Our findings set the foundation for a combinatorial therapeutic strategy using pulsatile targeted therapy together with immune checkpoint blockade in patients to optimally enhance tumor apoptosis and promote long-term immune response simultaneously. We are now continuing our studies using a KRAS G12C inhibitor to define its immune modulating properties and will then rationally combine with immune based therapy.
Citation Format: Hyejin Choi, Jiehui Deng, Shuai Li, Tarik Silk, Lauren Dong, Elliott J. Brea, Sean Houghton, David Redmond, Hong Zhong, Jonathan Boiarsky, Esra A. Akbay, Paul D. Smith, Taha Merghoub, Kwok-Kin Wong, Jedd D. Wolchok. Pulsatile MEK inhibition improves anti-tumor immunity and T cell function in Kras mutant lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 923.
Abstract 93: AMPK alpha1 and AMPK alpha 2 control TNBC proliferation through cell cycle regulation
Authors: Johnson Jeremy , Richahou Piotr , Evers B. Mark 
Published: September 2020

Abstract
Introduction. Triple negative breast cancer (TNBC) is very aggressive, has a higher metastatic rate than other breast cancer subtypes, and lacks traditional targetable factors. AMPK-activated protein kinase (AMPK) is an important energy regulator within the cell that also impacts cancer progression. AMPK's catalytic subunit is composed of α1 and α2 isoforms, but little is known about their individual roles in TNBC. The purpose of this study was to establish the specific function of each isoform in TNBC with respect to expression, cell proliferation, cell cycle progression, and metabolism.
Methods. (i) Immunohistochemistry, immunofluorescence, and immunoblotting were used to determine the expression and localization of AMPKα1 and AMPKα2 in TNBC PDX samples or cell lines. (ii) To study the role of each isoform individually, TNBC cells were transfected with siRNA to NTC, AMPKα1, or AMPKα2 (50 nM) and were either harvested for immunoblotting or subseeded for cell cycle analysis, proliferation assays, or Seahorse analysis.
Results. (i) AMPKα1 expression was localized in the cytoplasm of all 9 TNBC PDX cell lines, whereas AMPKα2 was expressed predominantly in the nucleus in 6 of the 9 of TNBC samples. IF analysis of MDA-MB-231 cells confirmed expression findings in the PDX cell lines with AMPKα1 expression noted in the cytoplasm and AMPKα2 expression in both the cytoplasm and nucleus. (ii) siRNA knockdown of AMPKα1 or AMPKα2 induced G1 cell cycle arrest and decreased proliferation of MDA-MB-231 cells. Moreover, knockdown of AMPKα1 decreased levels of cyclin D1 in MDA-MB-231, MDA-MB-468, and BT-20 cells. siRNA knockdown of AMPKα1, but not AMPKα2, led to decreased basal and compensatory glycolysis in MDA-MB-231 cells.
Conclusions. Our findings indicate that both AMPKα1 and AMPKα2 can impact cell cycle progression and proliferation in TNBC; both isoforms promote progression through the cell cycle, thus supporting the proliferative capacity of TNBC. Importantly, AMPKα1 may also affect TNBC proliferation by increasing energy availability through glycolysis.
Citation Format: Jeremy Johnson, Piotr Richahou, B. Mark Evers. AMPK alpha1 and AMPK alpha 2 control TNBC proliferation through cell cycle regulation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 93.
Abstract 931: Assessment of tumor mutational burden using a multiplex amplicon-based NGS target enrichment approach
Authors: LI Chenyu 
Published: September 2020

Abstract
Tumor mutational burden (TMB) is gaining significant importance in cancer therapeutics with its correlation to patient response to checkpoint inhibitor-base immunotherapy. A whole exome sequencing approach is traditionally used to assess TMB, but this approach is expensive and time consuming, requiring high sample inputs and complex workflows. Alternatively, a targeted enrichment strategy using multiplexed PCR can provide better coverage of regions of interest and reduce costs. But increasing the multiplexity of PCR, as required for tumor profiling, can lead to problems with non-specific interactions, poor uniformity, and high bias. In this study, we present a multiplex PCR-based strategy for targeting hundreds of genes for tumor profiling applications and assessment of TMB.
Paragon Genomics designed a 500-gene TMB panel which uses about 27,000 pairs of primers for target enrichment via multiplex PCR. The amplicons were designed to target short segments of about 113 bp on average to allow for target amplification from challenging fragmented samples such as FFPE DNA and cfDNA. The 27,000 pairs of PCR primers cover a total of 1.6 Mb (1.2 Mb of coding sequence). Paragon Genomics' CleanPlex® technology enables a streamlined library preparation workflow which includes a multiplex PCR step with the targeted primers, a subsequent cleanup step to remove by-products, and a final PCR step to add sequencer flow cell adapters and sample indexes.
The 500-gene TMB panel exhibits on-target rates of ~96% and uniformity at 0.2X mean of ~94%. Little to no GC bias or amplicon length bias is observed despite the highly multiplexed nature of this panel. At an average read depth of 3000 paired-end reads, 97% of the expected mutations with allele frequencies ≥ 5% were detected. Lastly, Paragon Genomics utilized an internally developed variant-calling algorithm to calculate the TMB values from sequenced libraries prepared from tumor cell line DNA. The advanced design of this panel along with the CleanPlex technology enables the rapid interrogation of these genes and of the TMB value in a robust assay.
Citation Format: Chenyu LI. Assessment of tumor mutational burden using a multiplex amplicon-based NGS target enrichment approach [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 931.
Abstract 933: Pre-clinical characterization of TIM-3 antibody NB002
Authors: Dong Xin , Dong Jannie , Ma Jun , Zhao Lianqi , Wang Haojie , Wang Binbin , Gao Qian , Pan Hui , Wang Dong , Shao Liegang 
Published: September 2020

Abstract
Targeting immune checkpoint molecules PD1 and CTLA-4 by activating the immune system have improved the lives of many cancer patients. However, this type of immunotherapy is not effective for all patients, suggesting that there are additional mechanisms of immune evasion. T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) has been reported to be expressed on exhausted T and NK cells within the tumor microenvironment. The data in many preclinical models suggest that targeting TIM-3 pathway might provide an additional immune modulation of this anti-tumor axis in cancer patients. We have developed a novel monoclonal antibody NB002 against TIM-3,which forms a high-affinity interaction with a unique epitope. NB002 can enhance IFN-gamma secretion and proliferation of these exhausted T cells that has increased TIM-3 expression. Moreover, TIM-3 is constitutively expressed on NK cells. TIM-3 blockade could enhance in vitro cytotoxic activity of NK cells. Altogether, our data shows that NB002 is capable of targeting exhausted T cells and NK cells resulting activation of antitumor immunity. Further preclinical assessment in vivo and in vitro for solid tumors will support clinical development of NB002.
Citation Format: Xin Dong, Jannie Dong, Jun Ma, Lianqi Zhao, Haojie Wang, Binbin Wang, Qian Gao, Hui Pan, Dong Wang, Liegang Shao. Pre-clinical characterization of TIM-3 antibody NB002 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 933.
Abstract 939: Evaluating anti-PD-1/4-1BB combination therapy: In vivo efficacy with humanized double knock-in mice
Authors: Gan Tian , Zhou Xiaofei , Hu Yuting , Shang Chengzhang , Ng Gary 
Published: September 2020

Abstract
The transmembrane protein receptor 4-1BB is a member of the tumor necrosis factor (TNF) receptor super family and is involved in the co-stimulation of immune cells. 4-1BB is expressed in activated CD4 helper T cells, B cells, natural killer cells, natural killer T cells, dendritic cells, and activated endothelium. Most regulatory T cells (Tregs) also express 4-1BB, but it remains unclear that whether agonistic antibody treatment exerts pro- or anti-suppressive effect on these cells. 4-1BB enhances tumor rejection because it is upregulated on T cells following activation as its engagement increases T cell proliferation and pro-inflammatory cytokine production. Despite of the toxicity of 4-1BB-targeting drugs associated with overt immune activation, new therapeutic modalities using 4-1BB targeting aptamers, as well as combination therapies with other immuno-modulatory and traditional anti-cancer treatments, have revived excitement for the use of 4-1BB agonists in the clinic.
Biocytogen has developed a double humanized B-hPD-1/h4-1BB mouse model to unlock the tremendous potential of combination therapy involving 4-1BB agonists and anti-PD-1 antibodies. In such model, mouse PD-1 gene exon 2, and 4-1BB gene exons 2-7 were replaced with their human counterparts. Murine colon cancer MC38 cells, humanized PD-L1 in MC38 cells, humanized PD-L1 in murine melanoma B16F10 cells, and murine lymphoma EL4 cells were subcutaneously implanted into homozygous B-hPD-1/h4-1BB mice. Combination treatment of Urelumab (anti-4-1BB) and Pembrolizumab (anti-PD-1) has shown enhanced inhibitory effects compared to single antibody treatments using the B-hPD-1/h4-1BB mice models. Based on these findings, it could be concluded that the B-hPD-1/h4-1BB double-humanized mouse model is a validated tool for in vivo evaluation of hPD-1 and h4-1BB antibody combination therapy.
Citation Format: Tian Gan, Xiaofei Zhou, Yuting Hu, Chengzhang Shang, Gary Ng. Evaluating anti-PD-1/4-1BB combination therapy: In vivo efficacy with humanized double knock-in mice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 939.
Abstract 954: Adverse immunomodulatory effects of chemotherapy on myeloid-derived suppressor cell compromise immune-checkpoint blockade efficacy
Authors: Kwong Tsz Tung , Wong Chi Hang , Zhou Jing Ying , Cheng Alfred Sze Lok , Chan Anthony Wing Hung , Chan Stephen Lam 
Published: September 2020

Abstract
Introduction: Intrinsic immunologic composition in liver tumor microenvironment (TME) may play a role in the heterogenous response towards immune-checkpoint blockade in hepatocellular carcinoma (HCC). In some cancers, it has been shown that cytotoxic chemotherapy is synergistic with checkpoint inhibitors. In this study, we evaluated the efficacy and immunomodulation of 5-FU and anti-PD-L1 in orthotopic liver cancer mouse model.
Method: The orthotopic mouse model was established with the murine HCC cell line RIL-175 through intrahepatic injection. The tumor-bearing mice was then treated with 5-FU (i.p.) 3 times per week at 20mg/kg. Anti-PD-L1(10mg/kg) was delivered (i.p.) every 5 days. Tumor growth was reflected by the luciferase intensity via in vivo imaging. Upon sacrifice, the tumor tissue, liver, spleen and blood sample were harvested, followed by subsequent immune profiling analysis using flow cytometry.
Results: Based on the tumor growth rate and endpoint tumor weight, anti-PD-L1 monotherapy induced a significant tumor reduction whereas 5-FU, either alone or combined with anti-PD-L1, did not have therapeutic effect as compared to vehicle control. Proportions of immunosurveillance cells including natural killer (NK) cells, CD8+ T cells and CD4+ T cells were drastically increased in the tumor site after anti-PD-L1 single treatment, but reduced in 5-FU-treated tumor. To depict the underlying regulation by chemotherapy, immunosuppressive components were also examined. Accumulation in myeloid cells, particularly CD11b+Gr-1+Ly6G+Ly6Cint polymorphonuclear myeloid-derived suppressor cells (P-MDSCs) were found to be a contributing factor to lymphocytes depletion when treated with 5-FU, hence counteracting the anti-tumor activity by PD-L1 blockade.
Conclusion: In summary, our data indicate that chemotherapeutics may impose immunosuppressive modulation in HCC TME and latently alter the therapeutic outcome against immune-checkpoint blockade. This study suggests that combination of chemotherapy with checkpoint inhibitors may not be a feasible approach for HCC. Acknowledgement: The study is supported by the Terry Fox Foundation.
Key Words: Tumor microenvironment (TME), Hepatocellular carcinoma, Chemotherapy, myeloid-derived suppressor cell (MDSC), anti-PD-L1, immunotherapy
Citation Format: Tsz Tung Kwong, Chi Hang Wong, Jing Ying Zhou, Alfred Sze Lok Cheng, Anthony Wing Hung Chan, Stephen Lam Chan. Adverse immunomodulatory effects of chemotherapy on myeloid-derived suppressor cell compromise immune-checkpoint blockade efficacy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 954.
Abstract 963: Metabolic signatures of chemotherapy damage in mature T cells that lead to poor proliferation
Authors: Das Rajat K. , Barrett David M. 
Published: September 2020

Abstract
We have previously described progressive T cell dysfunction (characterized by poor response to ex vivo stimulation) with cumulative chemotherapy exposure in pediatric patients. Chemotherapy appears to sensitize surviving T cells to activation induced cell death (AICD) with hallmarks of disordered metabolism, though the mechanism for each agent and the correct antidote varies. We used an in vitro model of chemotherapy exposure to identify signatures of damage in surviving T cells. T cells from healthy donors were exposed in vitro to doxorubicin, cytarabine and 4-hydroperoxycyclophosphamide (4-HPCP) and allowed to recover to assess the surviving cells as a model of the kinds of cells that are collected from pediatric patients for future adoptive cell therapies. T cells were assessed via the Agilent Seahorse platform for metabolic parameters including oxygen consumption (OCR), spare respiratory capacity (SRC) and glycolysis via extracellular acidification rate (ECAR). All classes of chemotherapy reduce OCR, whereas cytarabine reduces SRC. Doxorubicin increases ECAR and basal glycolysis. We analyzed the T cells via metabolites detected by mass spectrometry, which identified disordered glycolysis in doxorubicin treated cells, evidence of reactive oxygen species/glutathione in 4-HPCP and disordered polyamine synthesis with cytarabine. All classes inhibited T cell proliferation in response to CD3/28 stimulation, primarily due to AICD. We targeted each metabolic deficit with agents designed to support the metabolic pathways identified (2-deoxyglucose for doxorubicin, n-acetylcysteine for 4-HPCP and polyamine supplementation for cytarabine). Each agent was able to improve the proliferative response specific to the deficit, but there was no rescue across classes. We manufactured chimeric antigen receptor T cells (CART) from chemotherapy exposed T cells with and without rescue, and demonstrated improved cell recovery but not improved in vitro killing. Autologous T cells for adoptive cell therapy are currently collected after chemotherapy cycles in children, which may impact their suitability for CAR manufacture which requires ex vivo stimulation. Here we demonstrate each class of chemotherapy increases the susceptibility to AICD with a distinct metabolic hallmark in surviving cells. These metabolic pathways may be specifically targeted to reduce AICD during CAR manufacture, and thus potentially increase the yield from these patients.
Citation Format: Rajat K. Das, David M. Barrett. Metabolic signatures of chemotherapy damage in mature T cells that lead to poor proliferation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 963.
Abstract 974: Immune modulation following combination of TAK-164 with checkpoint inhibitors
Authors: Appleman Victoria A. , Smith Michael D. , Ganno Michelle , Hatten Tiquella , Borland Maria , Abu-Yousif Adnan O. 
Published: September 2020

Abstract
TAK-164 is an antibody drug conjugate comprised of a full length, fully human IgG1 monoclonal antibody (mAb) directed towards the human extra-cellular domain of guanylyl cyclase C (GCC). The mAb is conjugated using ImmunoGen's peptide-linked indolinobenzodiazepine DNA alkylator DGN549. Previously presented preclinical studies using TAK-164 have demonstrated single agent activity of TAK-164 in a panel of patient derived xenograft models of colorectal cancer grown in immunodeficient mice. With emerging evidence demonstrating the immunostimulatory activity of cytotoxic antibody drug conjugates we sought to explore the potential of TAK-164 in immune competent mice. A CT26 model was engineered to express human GCC, allowing us to test the ability of TAK-164 to modulate the tumor microenvironment, thereby potentiating the activity of checkpoint inhibitors. huGCC-CT26 tumor cells were implanted in the right flank of 6-8 week old BALB/c female mice and randomized when tumors were between 50-150mm3 and treated with a single intravenous administration of TAK-164 alone or in combination with checkpoint inhibition administered Intraperitoneally biweekly for 2 weeks and monitored for tumor growth. To understand if responses observed were driven by a response capable of inducing immunological memory we separated mice with complete responses and rechallenged with CT26 tumor cells on the opposite flank. While memory was observed in the mice that achieved complete response in the single agent groups, both frequency of complete response and tumor rejection was increased in groups treated with a combination of TAK-164 and immune checkpoint inhibition. We performed immunophenotyping studies which revealed broad immunomodulation of lymphoid and myeloid cells by TAK-164 and combination regimens. Collectively these data support further interrogation of immune checkpoint inhibition in combination with TAK-164.
Citation Format: Victoria A. Appleman, Michael D. Smith, Michelle Ganno, Tiquella Hatten, Maria Borland, Adnan O. Abu-Yousif. Immune modulation following combination of TAK-164 with checkpoint inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 974.
Abstract 980: Maligant ascites microenvironment skews M2/M1 macrophage polarization in ovarian cancer during peritoneal metastasis
Authors: Wang Huogang , Yung Mingo MH , Chen Arvin FS , Ngan Hextan YS , Chan David W. 
Published: September 2020

Abstract
Advanced ovarian cancers with peritoneal metastases are usually accompanied with metastatic recurrence and high mortality. Macrophages, as a primary cell population in the tumor microenvironment, can be active and polarized into heterogeneous tumor-associated macrophages (TAMs). Clinical evidence indicates that a high M2/M1 ratio of TAMs are commonly found in malignant ascites microenvironment (MAM), and is attributed to a poor prognosis in advanced ovarian cancers. However, the molecular mechanisms of macrophage polarization in MAM remain elusive. Here, we report that MAM could modulate Hippo and/or Wnt signaling cascades in facilitating M2 macrophage polarization. In this study, we firstly evidenced the heterogeneity macrophage populations in cancerous omental tissues and ascites cancer cell spheroids of ovarian cancers by multiplex immunohistochemical, flow cytometry and immunofluorescent analyses. Consistently, in vitro polarization model demonstrated that co-cultured monocyte (THP-1 and U937) with omentum conditioned medium (OCM) or ascites significantly led to more CD206+ M2 macrophage than CD86+ M1 macrophage or M2/M1 ratio. Quantitative RT-PCR (qPCR) analysis showed that TAM-related genes: CCL2, IL6, and IL10 genes were significantly upregulated in OCM treated macrophage. Intriguingly, OCM treated macrophage could significantly promotes ovarian cancer cell migratory capacities. Importantly, RNA-seq analysis identified Hippo and Wnt signaling cascades may play important roles in macrophage polarization in malignant OCM and ascites. Further investigations of these pathways in M2/M1 macrophage polarization in MAM are warranted.
Citation Format: Huogang Wang, Mingo MH Yung, Arvin FS Chen, Hextan YS Ngan, David W. Chan. Maligant ascites microenvironment skews M2/M1 macrophage polarization in ovarian cancer during peritoneal metastasis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 980.