Browsing by Author "Allen, Tyler"

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    Characterization of a castrate-resistant prostate cancer xenograft derived from a patient of West African ancestry.
    (Prostate cancer and prostatic diseases, 2021-10-13) Patierno, Brendon M; Foo, Wen-Chi; Allen, Tyler; Somarelli, Jason A; Ware, Kathryn E; Gupta, Santosh; Wise, Sandra; Wise, John P; Qin, Xiaodi; Zhang, Dadong; Xu, Lingfan; Li, Yanjing; Chen, Xufeng; Inman, Brant A; McCall, Shannon J; Huang, Jiaoti; Kittles, Rick A; Owzar, Kouros; Gregory, Simon; Armstrong, Andrew J; George, Daniel J; Patierno, Steven R; Hsu, David S; Freedman, Jennifer A

    Background

    Prostate cancer is a clinically and molecularly heterogeneous disease, with highest incidence and mortality among men of African ancestry. To date, prostate cancer patient-derived xenograft (PCPDX) models to study this disease have been difficult to establish because of limited specimen availability and poor uptake rates in immunodeficient mice. Ancestrally diverse PCPDXs are even more rare, and only six PCPDXs from self-identified African American patients from one institution were recently made available.

    Methods

    In the present study, we established a PCPDX from prostate cancer tissue from a patient of estimated 90% West African ancestry with metastatic castration resistant disease, and characterized this model's pathology, karyotype, hotspot mutations, copy number, gene fusions, gene expression, growth rate in normal and castrated mice, therapeutic response, and experimental metastasis.

    Results

    This PCPDX has a mutation in TP53 and loss of PTEN and RB1. We have documented a 100% take rate in mice after thawing the PCPDX tumor from frozen stock. The PCPDX is castrate- and docetaxel-resistant and cisplatin-sensitive, and has gene expression patterns associated with such drug responses. After tail vein injection, the PCPDX tumor cells can colonize the lungs of mice.

    Conclusion

    This PCPDX, along with others that are established and characterized, will be useful pre-clinically for studying the heterogeneity of prostate cancer biology and testing new therapeutics in models expected to be reflective of the clinical setting.
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    Mesenchymal Stem Cell/Red Blood Cell-Inspired Nanoparticle Therapy in Mice with Carbon Tetrachloride-Induced Acute Liver Failure.
    (ACS nano, 2018-07) Liang, Hongxia; Huang, Ke; Su, Teng; Li, Zhenhua; Hu, Shiqi; Dinh, Phuong-Uyen; Wrona, Emily A; Shao, Chen; Qiao, Li; Vandergriff, Adam C; Hensley, M Taylor; Cores, Jhon; Allen, Tyler; Zhang, Hongyu; Zeng, Qinglei; Xing, Jiyuan; Freytes, Donald O; Shen, Deliang; Yu, Zujiang; Cheng, Ke
    Acute liver failure is a critical condition characterized by global hepatocyte death and often time needs a liver transplantation. Such treatment is largely limited by donor organ shortage. Stem cell therapy offers a promising option to patients with acute liver failure. Yet, therapeutic efficacy and feasibility are hindered by delivery route and storage instability of live cell products. We fabricated a nanoparticle that carries the beneficial regenerative factors from mesenchymal stem cells and further coated it with the membranes of red blood cells to increase blood stability. Unlike uncoated nanoparticles, these particles promote liver cell proliferation in vitro and have lower internalization by macrophage cells. After intravenous delivery, these artificial stem cell analogs are able to remain in the liver and mitigate carbon tetrachloride-induced liver failure in a mouse model, as gauged by histology and liver function test. Our technology provides an innovative and off-the-shelf strategy to treat liver failure.
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    microRNA-21-5p dysregulation in exosomes derived from heart failure patients impairs regenerative potential.
    (The Journal of clinical investigation, 2019-04) Qiao, Li; Hu, Shiqi; Liu, Suyun; Zhang, Hui; Ma, Hong; Huang, Ke; Li, Zhenhua; Su, Teng; Vandergriff, Adam; Tang, Junnan; Allen, Tyler; Dinh, Phuong-Uyen; Cores, Jhon; Yin, Qi; Li, Yongjun; Cheng, Ke
    Exosomes, as functional paracrine units of therapeutic cells, can partially reproduce the reparative properties of their parental cells. The constitution of exosomes, as well as their biological activity, largely depends on the cells that secrete them. We isolated exosomes from explant-derived cardiac stromal cells from patients with heart failure (FEXO) or from normal donor hearts (NEXO) and compared their regenerative activities in vitro and in vivo. Patients in the FEXO group exhibited an impaired ability to promote endothelial tube formation and cardiomyocyte proliferation in vitro. Intramyocardial injection of NEXO resulted in structural and functional improvements in a murine model of acute myocardial infarction. In contrast, FEXO therapy exacerbated cardiac function and left ventricular remodeling. microRNA array and PCR analysis revealed dysregulation of miR-21-5p in FEXO. Restoring miR-21-5p expression rescued FEXO's reparative function, whereas blunting miR-21-5p expression in NEXO diminished its therapeutic benefits. Further mechanistic studies revealed that miR-21-5p augmented Akt kinase activity through the inhibition of phosphatase and tensin homolog. Taken together, the heart failure pathological condition altered the miR cargos of cardiac-derived exosomes and impaired their regenerative activities. miR-21-5p contributes to exosome-mediated heart repair by enhancing angiogenesis and cardiomyocyte survival through the phosphatase and tensin homolog/Akt pathway.
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    Targeted repair of heart injury by stem cells fused with platelet nanovesicles.
    (Nature biomedical engineering, 2018-01) Tang, Junnan; Su, Teng; Huang, Ke; Dinh, Phuong-Uyen; Wang, Zegen; Vandergriff, Adam; Hensley, Michael T; Cores, Jhon; Allen, Tyler; Li, Taosheng; Sproul, Erin; Mihalko, Emily; Lobo, Leonard J; Ruterbories, Laura; Lynch, Alex; Brown, Ashley; Caranasos, Thomas G; Shen, Deliang; Stouffer, George A; Gu, Zhen; Zhang, Jinying; Cheng, Ke
    Stem cell transplantation, as used clinically, suffers from low retention and engraftment of the transplanted cells. Inspired by the ability of platelets to recruit stem cells to sites of injury on blood vessels, we hypothesized that platelets might enhance the vascular delivery of cardiac stem cells (CSCs) to sites of myocardial infarction injury. Here, we show that CSCs with platelet nanovesicles fused onto their surface membranes express platelet surface markers that are associated with platelet adhesion to injury sites. We also find that the modified CSCs selectively bind collagen-coated surfaces and endothelium-denuded rat aortas, and that in rat and porcine models of acute myocardial infarction the modified CSCs increase retention in the heart and reduce infarct size. Platelet-nanovesicle-fused CSCs thus possess the natural targeting and repairing ability of their parental cell types. This stem cell manipulation approach is fast, straightforward and safe, does not require genetic alteration of the cells, and should be generalizable to multiple cell types.
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    Tumor cell-derived exosomes home to their cells of origin and can be used as Trojan horses to deliver cancer drugs.
    (Theranostics, 2020-01) Qiao, Li; Hu, Shiqi; Huang, Ke; Su, Teng; Li, Zhenhua; Vandergriff, Adam; Cores, Jhon; Dinh, Phuong-Uyen; Allen, Tyler; Shen, Deliang; Liang, Hongxia; Li, Yongjun; Cheng, Ke
    Cancer is the second leading cause of death worldwide and patients are in urgent need of therapies that can effectively target cancer with minimal off-target side effects. Exosomes are extracellular nano-shuttles that facilitate intercellular communication between cells and organs. It has been established that tumor-derived exosomes contain a similar protein and lipid composition to that of the cells that secrete them, indicating that exosomes might be uniquely employed as carriers for anti-cancer therapeutics. Methods: We isolated exosomes from two cancer cell lines, then co-cultured each type of cancer cells with these two kinds of exosomes and quantified exosome. HT1080 or Hela exosomes were systemically injected to Nude mice bearing a subcutaneous HT1080 tumor to investigate their cancer-homing behavior. Moreover, cancer cell-derived exosomes were engineered to carry Doxil (a common chemotherapy drug), known as D-exo, were used to detect their target and therapeutic efficacy as anti-cancer drugs. Exosome proteome array analysis were used to reveal the mechanism underly this phenomenon. Results: Exosomes derived from cancer cells fuse preferentially with their parent cancer cells, in vitro. Systemically injected tumor-derived exosomes home to their original tumor tissues. Moreover, compared to Doxil alone, the drug-loaded exosomes showed enhanced therapeutic retention in tumor tissues and eradicated them more effectively in nude mice. Exosome proteome array analysis revealed distinct integrin expression patterns, which might shed light on the underlying mechanisms that explain the exosomal cancer-homing behavior. Conclusion: Here we demonstrate that the exosomes' ability to target the parent cancer is a phenomenon that opens up new ways to devise targeted therapies to deliver anti-tumor drugs.