Digital Commons Network^™

Histone Deacetylase 8 Is A Novel Therapeutic Target For Mantle Cell Lymphoma And Preserves Natural Killer Cell Cytotoxic Function, January M. Watters

USF Tampa Graduate Theses and Dissertations

This study demonstrates for the first time that HDAC8 function is critical for MCL survival, and abrogating its activity in human primary NK cells does not interfere with NK IgG antibody directed ADCC therapies ex vivo. Human NK cells, isolated from healthy donors, are highly resistant to HDAC8 inhibitor treatment with PCI-34051. Even at the highest concentration, 20uM, no toxicity was observed. Conversely, MCL cell lines representative of the aggressive MCL subtype, classical MCL, were especially sensitive to PCI-34051, an HDAC8 selective inhibitor, treatment. Blocking HDAC8 activity and/or abrogating expression through shRNA silencing induced significant DNA damage, hyperacetylation of SMC3, …

Effect Of Atypical Protein Kinase C Inhibitor (Dnda) On Cell Proliferation And Migration Of Lung Cancer Cells, Raja Reddy Bommareddy

USF Tampa Graduate Theses and Dissertations

Lung cancer is the second most common cancer, and it is the leading cause of cancer death in both men and women. Elevated levels of PKC-ι and FAK are implicated in the progression of lung cancer and involved in cell proliferation, apoptosis, cell survival, and cell migration processes. Lung cancer diagnosis typically occurs in the late stages, which limits the treatment options. Hence, there is a dire need to develop drugs that are effective and safe to treat lung cancers. We used a novel aPKC inhibitor named DNDA (3,4-amino-2,7 napthalene disulfonic acid) to study the role of atypical PKCs (aPKCs) …

Vdr-Ripk1 Interaction And Its Implications In Cell Death And Cancer Intervention, Waise Quarni

USF Tampa Graduate Theses and Dissertations

Receptor interacting protein kinase 1 (RIPK1) is an enzyme acting downstream of tumor necrosis factor alpha to control cell survival and death. RIPK1 expression has been reported to cause drug resistance in cancer cells; but so far, no published studies have investigated the role of RIPK1 in vitamin D action. In the present study, we investigated whether RIPK1 played any role in 1,25-dihydroxyvitamin D3 (1,25D3)-induced growth suppression. In our studies, RIPK1 decreased the transcriptional activity of vitamin D receptor (VDR) in luciferase reporter assays independently of its kinase activity, suggesting a negative role of RIPK1 in 1,25D3 action. RIPK1 also …

Regulation Of The Tumor Suppresser P53 And Survivin By Ras And Ral Gtpases:Implications For Malignant Transformation, Awet G. Tecleab

USF Tampa Graduate Theses and Dissertations

Abstract

Although the critical role of the small GTPases Ras and Ral in oncogenesis has been well documented, much remains to be investigated about the molecular mechanism by which these GTPases regulate malignant transformation. The work under this thesis made two major contributions to this field. The first is the discovery that K-Ras, RalA and/or RalB are required for the maintenance of the high levels of the anti-apoptotic protein survivin in some human cancer cells, and the second is the demonstration that down regulation of K-Ras, RalA and/or RalB, but not Raf-1 or Akt1/2, stabilizes the tumor suppressor p53 and …

Design, Combinatorial Synthesis, And Biological Evaluation Of Novel Α-Helical Mimetics Based On Functionalized Piperazines As Antagonists Of P53/Mdm2 Interactions, Melissa Elizabeth Topper

USF Tampa Graduate Theses and Dissertations

The p53 protein promotes tumor eradication upon activation, making it an attractive target in cancer therapies. A reported 50% of all human cancers display aberrant activation of the MDM2 oncoprotein, which directly promotes tumorgenesis by inactivating the transcriptional activity of wild type p53, and is commonly associated with drug, chemo, and radio therapy resistance. Previously reported crystallographic analysis of the p53/MDM2 complex infers that the p53 protein forms a 2.5 turn amphipathic alpha helix whose hydrophobic face interacts within a deep hydrophobic cleft in the NH2-terminal domain of the globular MDM2. This suggests that the synthesis of small molecular antagonists …

The Role Of Microrna-155 In Human Breast Cancer, William Kong

USF Tampa Graduate Theses and Dissertations

Recent statistics reveal breast cancer as the most common cancer among women and accounts for approximately 41,000 mortalities per year. In diagnosis, features such as stage, grade, lymph node metastasis are important prognostic indicators that help guide physicians and oncologist towards optimal patient care. Presence of established pathological markers such as ER, PR, and Her2/neu status would indicate ideal adjuvant therapy situation. Although treatment of these types of breast cancer is well established, cancer that lack all three receptors, “triple negatives” or “basal like” do not respond to adjuvant therapy and are considered more aggressive in that patients tend to …

Design And Synthesis Of Substituted 1,4-Hydrazine-Linked Piperazine-2,5- And 2,6-Diones And 2,5-Terpyrimidinylenes As Α-Helical Mimetics, Laura Anderson

USF Tampa Graduate Theses and Dissertations

The most common secondary structure of proteins is the alpha-helix. The alpha-helix can be involved in various protein-protein interactions (PPIs) through the recognition of three or more side chains along one face of the alpha-helix (Wells and McClendon, 2007). In recent years, there has been an increasing interest in the development of peptidic and non-peptidic compounds that bind to PPI surfaces. We focused on the design and synthesis of compounds that mimic the orientation of side chain residues of an alpha-helical protein domain. Although our scaffolds could potentially inhibit various PPIs, we focused mainly on the disruption of interactions among …

The Rad9-Rad1-Hus1 Complex And Bif-1 Regulate Multiple Mechanisms That Affect Sensitivity To Dna Damage, Cheryl L. Meyerkord

USF Tampa Graduate Theses and Dissertations

The resistance of cancer cells to traditional chemotherapeutic agents is a major obstacle in the successful treatment of cancer. Cancer cells manipulate a variety of signaling pathways to enhance resistance to anticancer agents; such mechanisms include disrupting the DNA damage response and hyperactivating survival signaling pathways. In an attempt to better understand the molecular mechanisms that underlie resistance to chemotherapeutic agents, we investigated multiple processes regulated by the Rad9-Rad1-Hus1 (9-1-1) complex and Bif-1. The 9-1-1 complex plays an integral role in the response to DNA damage and regulates many downstream signaling pathways. Overexpression of members of this complex has been …

Role Of Protein Kinase C-Iota In Prostate Cancer, Hla Yee Win

USF Tampa Graduate Theses and Dissertations

Prostate cancer is one of the leading causes of death among males in the United States. In this study, we hypothesized that an activated PKC-iota-dependent anti-apoptotic pathway, drives the cell cycle proliferation and survival of prostate cancer cells.

We investigated the role of atypical PKC-iota (PKC-ι) in androgen- independent prostate DU-145 carcinoma, androgen-dependent prostate LNCaP carcinoma compared to transformed non-malignant prostate RWPE-1 cells. Western blotting and immunoprecipitations demonstrated that PKC-ι is associated with cyclin-dependent activating kinase (CAK/Cdk7) in androgen-dependent, RWPE-1 and LNCaP cells but not in androgen-independent DU-145 cells. Treatment of prostate RWPE-1 cells with PKC-ι silencing RNA (siRNA) decreased …

Regulation Of Foxo Stability And Activity By Mdm2 E3 Ligase, Wei Fu

USF Tampa Graduate Theses and Dissertations

Members of the forkhead class O (FOXO) transcription factors are tumor suppressors and key molecules that control aging and lifespan. The stability of mammalian FOXO proteins is controlled by proteasome-mediated degradation but general ubiquitin E3 ligases for FOXO factors remain to be defined. The current studies demonstrate that MDM2 bound to FOXO1 and FOXO3A and promoted their ubiquitination and subsequent degradation, a process apparently dependent on FOXO phopshorylation at PKB sites and on the E3 ligase activity of MDM2. The binding occurred between endogenous proteins and was involved the forkhead box of FOXO1 and the region of MDM2 that controls …

Endothelial Cell Mediators Of Angiogenesis In Bartonella Henselae Infection, Amy M. Mccord

USF Tampa Graduate Theses and Dissertations

Bacillary angiomatosis (BA), one of the clinical manifestations resulting from infection with the facultative intracellular bacterium Bartonella henselae, is characterized by angiogenic lesions. Endothelial cells have been identified as host cells for this pathogen and are presumed important for pathogenesis as lesions contain bacteria in direct contact with the endothelium. Lesions also contain infiltrating macrophages, which contribute to the angiogenic process during B. henselae infection by secreting vascular endothelial growth factor (VEGF). While virulence factors have been characterized, and the role for macrophages in B. henselae infection has been established, endothelial cell mediators of angiogenesis have not been well defined. …

Design And Synthesis Of Core Structural Intermediates For Novel Hiv-1 Protease Inhibitors & Synthesis, Biological Activity And Molecular Modeling Of Novel 20s Proteasome Inhibitors, Kiran Kumar Venkata Raja Avancha

USF Tampa Graduate Theses and Dissertations

HIV-1 protease binds to its peptide/protein substrates in extended conformations. Therefore protease inhibitors that are constrained to form extended conformations are likely to produce very active protease inhibitors. This is because they are pre-organized to form favorable interactions with the enzyme environment immediately surrounding the active site. With this hypothesis in mind, we designed a family of structurally related molecules, which contain dipeptide analogs constrained to adopt the extended conformation. Core structural intermediates that are required for the total synthesis of the novel class of HIV-1 protease inhibitors are outlined in Chapter One. Chapter Two discusses the enantioselective synthesis of …

Investigation Of The Effects Of Increased Levels Of O-Glcnac Protein Modification On Protein Kinase C And Akt, Jason Aaron Matthews

USF Tampa Graduate Theses and Dissertations

O-linked N-acetylglucosamine (O-GlcNAc) is an abundant and ubiquitous post-translational modification that has been shown to play a role in regulating a variety of intracellular processes. The pathway responsible for generating the O-GlcNAc modification, the hexosamine biosynthetic pathway (HBP), has also been shown to affect the activity and translocation of certain protein kinase C (PKC) isoforms. To investigate if the effects of HBP flux on PKC translocation observed by others is related to the O-GlcNAc modification, O-GlcNAc levels in human astroglial cells were elevated using four separate O-GlcNAc modulating agents followed by analysis of cytosol and membrane concentrations of PKC-epsilon, -alpha, …

The Role And Regulation Of Argininosuccinate Synthase In Endothelial Function, Bonnie L. Goodwin

USF Tampa Graduate Theses and Dissertations

While cellular levels of arginine greatly exceed the apparent Km for endothelial nitric oxide synthase (eNOS), nitric oxide (NO) production is limited by availability of arginine. Results from this work have provided a unique understanding of endothelial NO production, showing that arginine regeneration, that is the recycling of citrulline back to arginine by argininosuccinate synthase (AS) and argininosuccinate lyase (AL), defines the essential source of arginine for NO production. Using RNA interference analysis, selective reduction of AS expression was shown to directly correspond with a diminished capacity of endothelial cells to produce NO, despite saturating levels of arginine in the …

Molecular Mechanism Of Vitamin D Action And Its Implications In Ovarian Cancer Prevention And Therapy, Feng Jiang

USF Tampa Graduate Theses and Dissertations

1,25-dihydroxyvitamin D3 (1,25VD), the active form of vitamin D (VD), suppresses the growth of numerous human cancer cell lines by inhibiting cell cycle progression and inducing cell death. Genes that mediate each of these activities remain largely unidentified and there are no preclinical data for 1,25VD analogues in ovarian cancer (OCa). We hypothesize that 1,25VD and its analogues inhibit the development of OCa. In this study, we demonstrated, (a) 1,25VD causes cell cycle arrest at the G1/S and G2/M transition and induces apoptosis in OCa cells. (b) We also found that gadd45 is one of primary target genes for 1,25VD-mediated …