Browsing by Subject "Xenograft"

Now showing 1 - 4 of 4
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    Current Barriers to Clinical Liver Xenotransplantation
    (Frontiers Media, 2022-02-23) Cross-Najafi, Arthur A.; Lopez, Kevin; Isidan, Abdulkadir; Park, Yujin; Zhang, Wenjun; Li, Ping; Yilmaz, Sezai; Akbulut, Sami; Ekser, Burcin; Surgery, School of Medicine
    Preclinical trials of pig-to-nonhuman primate liver xenotransplantation have recently achieved longer survival times. However, life-threatening thrombocytopenia and coagulation dysregulation continue to limit preclinical liver xenograft survival times to less than one month despite various genetic modifications in pigs and intensive pharmacological support. Transfusion of human coagulation factors and complex immunosuppressive regimens have resulted in substantial improvements in recipient survival. The fundamental biological mechanisms of thrombocytopenia and coagulation dysregulation remain incompletely understood. Current studies demonstrate that porcine von Willebrand Factor binds more tightly to human platelet GPIb receptors due to increased O-linked glycosylation, resulting in increased human platelet activation. Porcine liver sinusoidal endothelial cells and Kupffer cells phagocytose human platelets in an asialoglycoprotein receptor 1-dependent and CD40/CD154-dependent manner, respectively. Porcine Kupffer cells phagocytose human platelets via a species-incompatible SIRPα/CD47 axis. Key drivers of coagulation dysregulation include constitutive activation of the extrinsic clotting cascade due to failure of porcine tissue factor pathway inhibitor to repress recipient tissue factor. Additionally, porcine thrombomodulin fails to activate human protein C when bound by human thrombin, leading to a hypercoagulable state. Combined genetic modification of these key genes may mitigate liver xenotransplantation-induced thrombocytopenia and coagulation dysregulation, leading to greater recipient survival in pig-to-nonhuman primate liver xenotransplantation and, potentially, the first pig-to-human clinical trial.
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    Emerging and Evolving Ovarian Cancer Animal Models
    (Libertas Academica, 2015-08-12) Bobbs, Alexander S.; Cole, Jennifer M.; Dahl, Karen D. Cowden; Department of Biochemistry and Molecular Biology, IU School of Medicine
    Ovarian cancer (OC) is the leading cause of death from a gynecological malignancy in the United States. By the time a woman is diagnosed with OC, the tumor has usually metastasized. Mouse models that are used to recapitulate different aspects of human OC have been evolving for nearly 40 years. Xenograft studies in immunocompromised and immunocompetent mice have enhanced our knowledge of metastasis and immune cell involvement in cancer. Patient-derived xenografts (PDXs) can accurately reflect metastasis, response to therapy, and diverse genetics found in patients. Additionally, multiple genetically engineered mouse models have increased our understanding of possible tissues of origin for OC and what role individual mutations play in establishing ovarian tumors. Many of these models are used to test novel therapeutics. As no single model perfectly copies the human disease, we can use a variety of OC animal models in hypothesis testing that will lead to novel treatment options. The goal of this review is to provide an overview of the utility of different mouse models in the study of OC and their suitability for cancer research.
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    In vivo tumor growth of high-grade serous ovarian cancer cell lines
    (Elsevier, 2015-08) Mitra, Anirban; Davis, David A.; Tomar, Sunil; Roy, Lynn; Gurler, Hilal; Xie, Jia; Lantvit, Daniel D.; Cardenas, Horacio; Fang, Fang; Liu, Yueying; Loughran, Elizabeth; Yang, Jing; Stack, M. Sharon; Emerson, Robert E.; Dahl, Karen D. Cowden; Barbolina, Maria; Nephew, Kenneth P.; Matei, Daniela; Burdette, Joanna E.; Department of Medicine, IU School of Medicine
    OBJECTIVE: Genomic studies of ovarian cancer (OC) cell lines frequently used in research revealed that these cells do not fully represent high-grade serous ovarian cancer (HGSOC), the most common OC histologic type. However, OC lines that appear to genomically resemble HGSOC have not been extensively used and their growth characteristics in murine xenografts are essentially unknown. METHODS: To better understand growth patterns and characteristics of HGSOC cell lines in vivo, CAOV3, COV362, KURAMOCHI, NIH-OVCAR3, OVCAR4, OVCAR5, OVCAR8, OVSAHO, OVKATE, SNU119 and UWB1.289 cells were assessed for tumor formation in nude mice. Cells were injected intraperitoneally (i.p.) or subcutaneously (s.c.) in female athymic nude mice and allowed to grow (maximum of 90 days) and tumor formation was analyzed. All tumors were sectioned and assessed using H&E staining and immunohistochemistry for p53, PAX8 and WT1 expression. RESULTS: Six lines (OVCAR3, OVCAR4, OVCAR5, OVCAR8, CAOV3, and OVSAHO) formed i.p xenografts with HGSOC histology. OVKATE and COV362 formed s.c. tumors only. Rapid tumor formation was observed for OVCAR3, OVCAR5 and OVCAR8, but only OVCAR8 reliably formed ascites. Tumors derived from OVCAR3, OVCAR4, and OVKATE displayed papillary features. Of the 11 lines examined, three (Kuramochi, SNU119 and UWB1.289) were non-tumorigenic. CONCLUSIONS: Our findings help further define which HGSOC cell models reliably generate tumors and/or ascites, critical information for preclinical drug development, validating in vitro findings, imaging and prevention studies by the OC research community.
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    Melatonin and Andrographolide synergize to inhibit the colospheroid phenotype by targeting Wnt/beta-catenin signaling
    (Wiley, 2022) Sokolov, Daniil; Sharda, Neha; Giri, Banabihari; Hassan, Md Sazzad; Singh, Damandeep; Tarasiewicz, Agnieszka; Lohr, Charity; von Holzen, Urs; Kristian, Tibor; Waddell, Jaylyn; Reiter, Russel J.; Ahmed, Hafiz; Banerjee, Aditi; Surgery, School of Medicine
    β-catenin signaling, and angiogenesis are associated with colospheroid (CSC), development. CSCs, spheroids derived from colon cancer cells, are responsible for metastasis, drug resistance, and disease recurrence. Whether dysregulating β-catenin and inhibiting angiogenesis reduces CSC growth is unknown. In this study, the molecular mechanism of CSC growth inhibition was evaluated using a novel combination of melatonin (MLT) and andrographolide (AGP). These drugs have anti-carcinogenic, antioxidant, and anti-metastatic properties. CSCs were obtained from two metastatic colon cancer cell lines (HT29 and HCT-15). The viability and stemness were monitored (FDA PI staining and immunoblot for CD44, CD133, Nanog, Sox2 and Oct4). The drug combination synergistically diminished stemness via increased ROS levels, reduced mitochondrial membrane potential and ATP level. MLT+AGP induced cell death by inhibiting β-catenin expression and its downregulatory signals, Cyclin D1, c-Myc. MLT+AGP treated cells exhibited translocation of phospho-β-catenin to the nucleus and de-phosphorylated-β-catenin. Downregulation of β-catenin activation and its transcription factors (TCF4, LEF1) and GTP binding/G-protein related activity were found in the dual therapy. Angiogenic inhibition is consistent with downregulation of VEGF mRNA transcripts (VEGF189), phosphorylated VEGF receptor protein expression, matrigel invasion, and capillary tube inhibition. In vivo, the intravenous injection of MLT+AGP slowed HT29 metastatic colon cancer. Histopathology indicated significant reduction in microvascular density and tumor index. Immunohistochemistry for caspase 7, and β-catenin found increased apoptosis and downregulation of β-catenin signals. The mechanism(s) of decreased colospheroids growth were the inhibition of the Wnt/β-catenin pathway. Our results provide rationale for using MLT in combination with AGP for inhibition of CRCs.