tbuckley/cabot-search huggingface dataset:
Abstract 4191: Delayed onset of GvHD in PBMC humanized NCG-B2m KO mice provides an enhanced model for oncology studies
Authors: Steven Bronson, David Harris, Anya Avrutskaya, Christoph Eberle, Jenny Rowe
Journal: Cancer Research (2024)

Abstract Humanized mice are specialized animal models incorporating components of the human immune system. These models are valuable tools for assessing the efficacy of human immunotherapies on tumors. Humanized mice are created by injecting human CD34+ hematopoietic stem cells (HSCs) or human peripheral blood mononuclear cells (PBMCs) into an immunodeficient mouse. PBMC humanized (HuPBMC) mice engraft within a few weeks and can recapitulate a robust human T cell population. One challenge when using HuPBMC mice is the onset of graft versus host disease (GvHD), limiting their lifespan compared to hCD34+ HSC humanized mice. The onset of GvHD varies in the HuPBMC model depending on the donor cells. The development of xenogeneic GvHD is dependent on the expression of major histocompatibility complex (MHC) on host cells and lowering MHC expression can delay the onset of GvHD.NCG-B2m KO mice lack beta-2 microglobulin, a component of MHC I, and have lower cell surface expression of MHC I molecules. This leads to a decrease in recognition of host cells by human immune cells. Here we compared the onset of GvHD between HuPBMC NCG-B2m KO mice and HuPBMC NCG mice. PBMC donor variability was also compared between the two PBMC humanized models by evaluating multiple donors and assessing additional collections from the same donor. After the PBMC engraftment was characterized, HuPBMC NCG mice and HuPBMC NCG-B2m KO mice were enrolled in tumor studies comparing outcomes and tumor growth kinetics in mice treated with human immune checkpoint blockade therapy.NCG and NCG-B2m KO mice were injected with 1x107 PBMCs from individual donors. Animals were weighed three times a week to monitor for changes in body weight and general health status. Peripheral blood was collected at day 10, 20, 30, 40, 60 and 90 post injection for flow cytometry screening of human immune cell engraftment (hCD45+, hCD3+, hCD4+ and hCD8+). Human PBMCs isolated from additional collections from the same donors were also injected into both NCG-B2m KO mice and NCG mice and flow cytometry was performed. HuPBMC NCG-B2m KO mice survived longer than HuPBMC NCG mice allowing for the potential use in longer term tumor studies before the results are confounded by GvHD. PBMC humanized mice are an important model for translational research using immunotherapies and the PBMC humanized NCG-B2m KO model provides an expanded study window ideal for oncology studies. Citation Format: Steven Bronson, David Harris, Anya Avrutskaya, Christoph Eberle, Jenny Rowe. Delayed onset of GvHD in PBMC humanized NCG-B2m KO mice provides an enhanced model for oncology studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4191.
Abstract 611: Discovery of LNX231, a multi-kinase inhibitor mainly target FLT3 with robust <i>in vivo</i> efficacy in FLT3 mutant AML models
Authors: Lizhi Zhao, Guizhou Hao, Rong Deng, Naihua Zhang, Jingchun Yao, Anguo Zhu, Guangyan Li, Enli Wang, Zhenyu Li, Zhong Liu, Guimin Zhang
Journal: Cancer Research (2024)

Abstract LNX231 is a multi-kinase inhibitor mainly target FLT3, which could both directly kill cancer cells and promote tumor immunity. LNX231 potently inhibits FLT3 activity in biochemical assay, with a 50% inhibitory concentration (IC50) of 3.5 nM, significantly inhibits FLT3-D835Y and FLT3 ITD, the values of IC50 are 20 nM and 4.4 nM. LNX231 inhibits the proliferation of FLT3 mutant AML cell lines via RAS-MARK and JAK-STAT pathway. LNX231 significantly decreases the phosphorylation of STAT5 and ERK in MV-4-11 cells at the high concentration, but has no effect on the phosphorylation of FLT3 and AKT. LNX231 significantly decreases the phosphorylation of FLT3, STAT5 and ERK in MOLM-13 cells at the high concentration, but has no effect on the phosphorylation of AKT. In FLT3 mutated AML models, LNX231 induced sustained tumor shrinkage as a single agent and was well tolerated. At the same dose, LNX231 was more potent than the FDA-approved drug Gilteritinib. In the MC38 tumor-bearing model, the efficacy of LNX231 was better than Sunitinib and Lenvatinib. LNX231 has good oral bioavailability in different species, such as mouse, rat, dog and monkey. DMPK data predicted oral QD dosing in human. It also showed excellent ADMET profile as a pre-clinical candidate. Safety tolerability studies were conducted in mice and dogs. LNX231 has low cardiotoxicity (IC50 of hERG is 25.84 µM) and 5-6 times safety window. In conclusion, we discovered LNX231 as a multi-kinase inhibitor for FLT3 mutated AML. Citation Format: Lizhi Zhao, Guizhou Hao, Rong Deng, Naihua Zhang, Jingchun Yao, Anguo Zhu, Guangyan Li, Enli Wang, Zhenyu Li, Zhong Liu, Guimin Zhang. Discovery of LNX231, a multi-kinase inhibitor mainly target FLT3 with robust in vivo efficacy in FLT3 mutant AML models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 611.
Abstract 3114: Development of HTS enzymatic assays for RNA helicases: DDX3, DDX5, DDX17, RIG-1 and MDA5
Authors: Mahbbat Ali, Ha Pham, Anibal Ramos Martinez, Robert Lowery
Journal: Cancer Research (2024)

Abstract RNA helicases are a broad class of enzymes that bind and modify RNA in an ATP-dependent manner and play diverse roles in RNA metabolism, regulation of gene expression, and innate immunity. Several RNA helicases, especially in the dead box helicase (DDX) family, have been shown to be dysregulated in cancer, and there have been limited efforts to develop small molecule inhibitors. To accelerate development of selective helicase inhibitors while avoiding off target effects, especially with helicases that promote tumor immunity, we are assembling a panel of high throughput biochemical assays using the Transcreener ADP2 assay for homogenous detection of RNA-dependent ATPase activity with a far-red fluorescence polarization (FP) readout. Here we describe development of assays for DDX3, DDX17 and DDX5, which have all been implicated in cancer, and the Rig-1-like receptor (RLR) helicases, RIG-1 and MDA5, which trigger expression of type I interferons important for tumor immunity. We produced the recombinant enzymes using BaV-infected insect cells, as full-length polypeptides, or in some cases truncated to remove disordered N-terminal domains. We determined RNA substrate and cofactor requirements and kinetic parameters with the purified enzymes and optimized the assays for initial velocity detection of RNA-dependent ATPase activity with a Z’ value greater than 0.7, ensuring a sufficient signal window for inhibitor screening and dose response assays. We validated each of the helicase ATPase assays for HTS by screening a collection of bioactives (Tocris 2.0) and confirming hits in dose response mode with the enzymatic assay and with thermal shift assays to confirm target binding. These assays will enable screening and hit-to-lead/SAR for DDX helicases that drive tumorigenesis as well as selectivity profiling to avoid off target effects with RLR helicases that promote tumor immunity. Citation Format: Mahbbat Ali, Ha Pham, Anibal Ramos Martinez, Robert Lowery. Development of HTS enzymatic assays for RNA helicases: DDX3, DDX5, DDX17, RIG-1 and MDA5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3114.
Abstract 5649: PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath tumors
Authors: Shota Takihira, Eiji Nakata, Daisuke Yamada, Tatsunori Osone, Tomoka Takao, Takeshi Takarada, Akira Hirasawa, Takuto Itano, Tomohiro Fujiwara, Toshiyuki Kunisada, Toshifumi Ozaki
Journal: Cancer Research (2024)

Abstract Background: Paired related-homeobox 1 (PRRX1) is a transcription factor in the regulation of developmental morphogenetic processes. There is growing evidence that PRRX1 is highly expressed in certain cancers and is critically involved in human survival prognosis. However, the molecular mechanism of PRRX1 in cancer malignancy remains to be elucidated. Methods: PRRX1 expression in human Malignant peripheral nerve sheath tumors (MPNSTs) samples was detected immunohistochemically to evaluate survival prognosis. MPNST models with PRRX1 gene knockdown or overexpression were constructed in vitro, and the phenotype of MPNST cells was evaluated. Bioinformatics analysis combined with co-immunoprecipitation, mass spectrometry, RNA seq, and structural prediction were used to identify proteins interacting with PRRX1. Results: High expression of PRRX1 was associated with a poor prognosis for MPNST. PRRX1 knockdown suppressed the tumorigenic potential. PRRX1 overexpressed in MPNSTs directly interacts with topoisomerase 2A (TOP2A) to cooperatively promote epithelial-mesenchymal transition and increase expression of tumor malignancy-related gene sets including mTORC1, KRAS, and SRC signaling pathways. Etoposide, a TOP2A inhibitor used in the treatment of MPNST, may exhibit one of its anticancer effects by inhibiting the PRRX1-TOP2A interaction. Conclusion: Targeting the PRRX1-TOP2A interaction in malignant tumors with high PRRX1 expression might provide a novel tumor-selective therapeutic strategy. Significance: MPNST is a malignant tumor with a poor prognosis and still lacks definitive treatment. Our results could hold promise as an alternative therapeutic strategy to inhibit the interaction between PRRX1 and TOP2A, and may improve the prognosis for malignant tumor patients with high expression of PRRX1 and TOP2A such as MPNSTs. Citation Format: Shota Takihira, Eiji Nakata, Daisuke Yamada, Tatsunori Osone, Tomoka Takao, Takeshi Takarada, Akira Hirasawa, Takuto Itano, Tomohiro Fujiwara, Toshiyuki Kunisada, Toshifumi Ozaki. PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5649.
Abstract 61: A novel immunotherapy for metastatic prostate cancer: A monoclonal antibody that can bind both STEAP1 and STEAP2
Authors: Minzhi Sheng, Gobi Thillainadesan, Amanda Sparkes, Boyang Su, Esther Matus, Jessica Wright, Stanley Liu, Jean Gariepy, Hon S. Leong
Journal: Cancer Research (2024)

Abstract Prostate cancer (PCa) is the second most prevalent cancer among males, and the 5-year survival rate for patients with metastatic PCa (mPCa) is ~30%. Although significant progress has been made in improving survival in mPCa patients, many of these patients experience relapse or systemic toxicities. Protein expression of prostate-specific membrane antigen (PSMA), a common PCa antigen often targeted in PCa therapy, is unfortunately lost in the later stages of mPCa. In contrast, six transmembrane epithelial antigen of the prostate 1 and 2 (STEAP1 and STEAP2) are both overexpressed in most PCa compared to normal and vital organs and has emerged as a next-generation target in mPCa. We hypothesize that an antibody that binds to both STEAP1 and STEAP2 via their second extracellular domain (60% homology) could be useful therapeutically. Using an immunogen of this second extracellular domain, we raised several antibody clones that appear to have an affinity towards both STEAP1 and STEAP2 (STEAP1/2). The specificity and affinity of these antibody clones were successfully determined by immunofluorescence, flow cytometry and ELISA. Immunofluorescence results in PCa cell lines and those that overexpress STEAP1 and STEAP2 demonstrate the potential specificity of one clone for human STEAP1 and STEAP2. In addition, ELISA data revealed that the binding affinity of this clone to STEAP1 and STEAP2 is in the low nanomolar and low micromolar range, respectively. This monoclonal STEAP1/2 antibody has been sequenced and will become the basis for future development of immunotherapies thus expanding the therapeutic armamentarium for mPCa. Citation Format: Minzhi Sheng, Gobi Thillainadesan, Amanda Sparkes, Boyang Su, Esther Matus, Jessica Wright, Stanley Liu, Jean Gariepy, Hon S. Leong. A novel immunotherapy for metastatic prostate cancer: A monoclonal antibody that can bind both STEAP1 and STEAP2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 61.
Abstract 4193: Digital PCR as a novel way to assess chimerism of humanized immune system mice
Authors: Nicholas Smith, Sarah Hansen, Robert S. Livingston, Steve Smith, Paula Roesch, Megan M. MacBride
Journal: Cancer Research (2024)

Abstract Humanized immune system (HIS) mice contain human and murine immune cells. Analysis of chimerism in HIS mice is typically accomplished via flow cytometry, but this requires collecting a 75 μl blood sample and access to a flow cytometer. Repeated bleeding can negatively affect the health of HIS mice, limiting serial analysis. Digital PCR offers a novel method for chimerism analysis, which uses much smaller blood volumes and can be performed on clotted or frozen samples, sample types unsuitable for flow cytometry. A digital PCR assay directly comparing the presence of three human genes and one murine gene was developed. This assay was validated in the huNOG-EXL HIS mouse engrafted with CD34+ hematopoetic stem cells from 3 unique donors via blind comparison with chimerism data from flow cytometry. At 10 weeks post engraftment, the digital PCR assay showed excellent correlation for all three human genes against chimerism as measured by flow cytometry of the peripheral blood. This assay represents a new, user-friendly, rapid tool for the analysis of HIS mice and may permit serial chimerism measurement using 10 μL whole blood. This assay may be useful to investigate other mouse-human chimera models, including mice harboring functional human hepatocytes, tumors, and other cells. Citation Format: Nicholas Smith, Sarah Hansen, Robert S. Livingston, Steve Smith, Paula Roesch, Megan M. MacBride. Digital PCR as a novel way to assess chimerism of humanized immune system mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4193.
Abstract 6103: The association of genetic polymorphisms in DNA repair genes XRCC1 and 3 with cervical cancer risk among Bangladeshi females
Authors: Md Mustafizur Rahman, Laboni Das, Sadia Rahman, Amir Hossain, Razia Sultana
Journal: Cancer Research (2024)

Abstract Introduction and Objective: Worldwide, cervical cancer ranks the second most common cancer in women. Sequence variations in DNA repair genes X-ray repair cross complementing (XRCC) 1 and 3 genes can lead to can result cellular function aberration leading to cancers. Single nucleotide polymorphisms (SNPs) in XRCC1 (Arg399Gln) and XRCC3 (Thr241Met) genes have been shown to cause individual variation in their DNA repair capacity. The aim of this study was to investigate the association of XRCC1 Arg399Gln and XRCC3 Thr241Met SNPs with susceptibility to cervical cancer among Bangladeshi populations. Methods: In the current case-control study 124 cervical cancer patients and 148 age matched healthy controls were recruited. Genomic DNAs were isolated from peripheral blood collected from the participants and genotyped for candidate SNPs using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: For XRCC1, heterozygous Arg/Gln and combined heterozygous plus variant homozygous Gln/Gln genotypes showed 1.78-fold (95% CI 1.0037 to 2.8771, p=0.0484) and 1.8627-fold (95% CI 1.1470 to 3.0250, p = 0.0119) increased risk of cervical cancer, respectively, when compared with normal homozygous Arg/Arg genotype. The variant Gln allele was positively associated with cervical cancer by 1.68-fold increase (95% CI 1.1732 to 2.3980, p = 0.0046). Similarly, for XRCC3, Thr/Met heterozygous and combined Thr/Met + Met/Met genotypes were found to be associated with 1.6993-fold (95% CI 1.0398 to 3.0166, p=0.0354) and 1.8312-fold (95% CI 1.0890 to 3.0791, p = 0.0225) higher risk, respectively, when compared with normal homozygous Thr/Thr genotypes. The variant Met allele showed significant association with 1.71-fold increased risk. Conclusion: XRCC1 (Arg399Gln) and XRCC3 (Thr241Met) SNPs may be positively associated with increased cervical cancer risk in Bangladeshi females. Citation Format: Md Mustafizur Rahman, Laboni Das, Sadia Rahman, Amir Hossain, Razia Sultana. The association of genetic polymorphisms in DNA repair genes XRCC1 and 3 with cervical cancer risk among Bangladeshi females [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6103.
Abstract 4186: Development of an orthotopic A549 lung carcinoma model in CD34+ humanized NCG mice and response to treatment with paclitaxel and pembrolizumab
Authors: Anya Avrutskaya, Elizabeth Rainbolt, Bincy John, Cara Clouse, Murray Stackhouse, Christopher Currie, Sydney Scatigno, Steven Bronson, Jenny Rowe, Chassidy Hall, David P. Harris
Journal: Cancer Research (2024)

Abstract Translational in vivo models are needed to expedite the discovery of new treatments for lung cancer. One such approach is the use of humanized mouse models that enable immunotherapies targeting human immune cells to be evaluated for efficacy and tolerability. We developed an orthotopic lung carcinoma model in humanized mice (HuCD34 NCG), utilizing serial bioluminescence imaging to evaluate the activity of paclitaxel and pembrolizumab as single and combination agents. Paclitaxel, which disrupts microtuble function, and pembrolizumab, a PD-1-targeting immunotherapy, are both approved for the treatment of certain types of lung cancer. Paclitaxel kills cancer cells directly, and may also promote anti-tumor responses through enhanced presentation of tumor antigens and activation of T cells. Immunodeficient NCG mice were humanized with cord blood-derived hCD34+ stem cells from 3 donors. High levels of human cell engraftment, with expected frequencies of hCD45+ cells and other immune subsets, was observed by 14 weeks post-injection. Luciferase expressing A549 cells were implanted orthotopically into the pulmonary space of the left lobe of the lung, and animals were subsequently flux sorted into treatment groups. Tumor burden, measured by luciferase expression, increased progressively in untreated animals, and moribundity was often associated with clinical indications of respiratory distress. Treatment with paclitaxel significantly decreased the tumor burden and extended survival. In contrast, pembrolizumab did not control tumor growth or extend survival. There was no synergistic effect with the combination therapy, in fact, the addition of pembrolizumab was associated with a modest increase in tumor burden and disease progression. Comparative analysis of immune cell composition, function and persistence in lung and other tissues provided insights into the distinct pharmacodynamic responses associated with the different treatment regimens. This model establishes a robust in vivo platform to identify novel therapies for the treatment of lung cancer. Citation Format: Anya Avrutskaya, Elizabeth Rainbolt, Bincy John, Cara Clouse, Murray Stackhouse, Christopher Currie, Sydney Scatigno, Steven Bronson, Jenny Rowe, Chassidy Hall, David P. Harris. Development of an orthotopic A549 lung carcinoma model in CD34+ humanized NCG mice and response to treatment with paclitaxel and pembrolizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4186.
Abstract 5409: Phosphorylated focal adhesion kinase by mild reduction of cell surface proteins inhibits integrin α5β1-dependent patient- derived cancer cell migration and invasion
Authors: Joo Hyun Kim, Laurensia D. Anggradita, Sung Sik Hur, Jae Hong Park, Sang-Heon Kim, Myung Jin Ban, Yongsung Hwang
Journal: Cancer Research (2024)

Abstract Although head and neck squamous cell carcinomas (HNSCCs), including tongue, vocal cord, and buccal cancers, are one of the most common cancers worldwide with a mortality rate of more than 40%, there have been no solid standard biomarkers for effectively diagnosing HNSCCs at early stages and no effective protocols available to support in vitro expansion of HNSCC cells. To establish a cell culture method to support in vitro self-renewal of HNSCC cells, patient-derived tumor was enzymatically digested, and the tongue cancer epithelial cells were seeded onto feeder cells with the Rho kinase inhibitor (Y-27632). Additionally, to test our hypothesis that free thiol groups in the cells, generated by a mild reduction of cell surface proteins using the reducing agent tris(2-carboxyethyl) phosphine hydrochloride (TCEP), would modulate cancer cell adhesion and migration, we assessed the expression levels of integrins, focal adhesion kinase (FAK), and phosphorylated FAK (pFAK) of tongue cancer epithelial cells cultured on both soft and rigid polyacrylamide (PAAm) hydrogel-based cell culture substrates. Patient-derived tongue cancer epithelial cells exhibited self-renewal ability and maintained cancerous phenotypes, with high expressions of P53, Ki67, E-cadherin, CD44, and AHDH1A1. Treatment with the reducing agent (TCEP) increased the degree of cell adhesion through the significantly upregulated integrin α5β1-mediated phosphorylation of FAK, resulting in inhibited single-cell and collective cell migration as well as invasion. Additionally, when these cells were cultured on stiff PAAm hydrogels mimicking the tumor microenvironment, the cells exhibited accelerated cell migration behaviors, compared to cells on soft hydrogels. These results highlight the synergetic contributions of feeder cells and Rho kinase inhibitor to support long-term self-renewal of tongue cancer patient-derived epithelial cells. Citation Format: Joo Hyun Kim, Laurensia D. Anggradita, Sung Sik Hur, Jae Hong Park, Sang-Heon Kim, Myung Jin Ban, Yongsung Hwang. Phosphorylated focal adhesion kinase by mild reduction of cell surface proteins inhibits integrin α5β1-dependent patient- derived cancer cell migration and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5409.