Medical Pharmacology Commons^™

An Investigation Of The Anti-Stemness Actions Of Two Mirnas After Their Induction By Aminoflavone In Luminal A Breast Cancer, Nicole Ursula Rumbidzai Mavingire

Loma Linda University Electronic Theses, Dissertations & Projects

Approximately 40% of estrogen receptor positive breast cancer (BC) patients develop resistance to endocrine therapy (ET) agents like tamoxifen (Tam). Resistance promotes metastasis, recurrence, and death since metastatic BC is often incurable. Breast cancer stem cells (CSCs) greatly contribute to disease progression and drug resistance. We previously showed that aryl hydrocarbon receptor (AhR) agonist aminoflavone (AF) inhibits the expression of CSC biomarker α6-integrin (ITGA6) to disrupt the formation of endocrine-sensitive and -resistant luminal A mammospheres. In this study, we performed miRNAsequencing analysis of luminal A MCF-7 and MCF-7TamR mammospheres before and after AF treatment to further develop the mechanism of …

Phytochemical And Synthetic Ahr Ligands As Novel Therapy For Refractory Breast Cancer, Jonathan V. Wooten

Loma Linda University Electronic Theses, Dissertations & Projects

Patients with triple-negative breast cancer (TNBC) possess tumors that lack estrogen receptor, progesterone receptor, and human growth factor receptor 2 expression. Such patients have lower survival rates than those diagnosed with other breast cancer subtypes in part, due to the scarcity of targeted therapy for TNBC. In addition to chemotherapy, patients with TNBC often consume natural remedies, which has led us and others to evaluate the ability of plant isolates to confer anticancer and chemopreventive actions. Poly-ADP ribose polymerase (PARP) is an enzyme that promotes DNA single-strand break repair. PARP inhibitor olaparib exploits DNA repair enzyme deficiency in tumors to …

Contribution Of The Ledgf/P75 Protein Interactome To Prostate Cancer Chemoresistance, Greisha Lee Ortiz Hernández

Loma Linda University Electronic Theses, Dissertations & Projects

Prostate Cancer (PCa) progression leads to an advanced stage called metastatic castration resistant PCa (mCRPC), for which currently there is no cure in spite of advances in treatment with new generation anti-androgen drugs and chemotherapy with taxanes such as docetaxel (DTX). Our laboratory demonstrated previously that the stress oncoprotein Lens Epithelium Derived Growth Factor of 75 kD (LEDGF/p75) is upregulated in clinical prostate tumors and contributes to DTX-resistance in mCRPC cells. However, little is known about the molecular mechanisms by which LEDGF/p75 promotes taxane resistance. The C-terminus of LEDGF/p75 contains a domain called the Integrase Binding Domain (IBD), which in …

Aminoflavone Inhibits Α6-Integrin And Growth Of Tamoxifen Resistant Breast Cancer, Petreena S. Campbell

Loma Linda University Electronic Theses, Dissertations & Projects

Approximately 40% of estrogen receptor positive (ER+) breast cancer patients develop resistance to standard of care agent tamoxifen, while ER negative (ER-) breast cancer patients are intrinsically resistant to tamoxifen. Resistance often promotes metastasis, recurrence and death. Tumor-initiating cells (TICs) represent key contributors to resistance and adhesion protein α6-integrin is a putative TIC biomarker. Investigational agent Aminoflavone (AF) demonstrates efficacy against breast cancer cells irrespective of ER status. Interestingly, we found tamoxifen resistant (TamR) cells and tumors exhibited elevated α6-integrin expression in comparison to their tamoxifen sensitive counterparts. AF effectively disrupted mammospheres enriched for TICs and reduced α6-integrin levels in …

Targeting Ledgf/P75 To Sensitize Chemoresistant Prostate Cancer Cells To Taxanes, Leslimar Rios-Colón

Loma Linda University Electronic Theses, Dissertations & Projects

Prostate cancer (PCa) is the second most diagnosed cancer in males. This disease disproportionately affects African American men, with a higher incidence and mortality compared to other ethnic/racial groups. An aging male population and the complexity of addressing the health disparities associated with this disease puts PCa into the spotlight due to its serious public health implications and the imminent fiscal challenge over the next decades. Chronic prostate inflammation resulting in activation of stress and prosurvival pathways contribute to disease progression and the development of chemoresistance. Lens epithelium-derived growth factor p75 (LEDGF/p75) is a stressresponse protein that promotes cellular survival …

Anti-Tumor Mechanisms Of Hpv16 E6*, Whitney S. Evans

Loma Linda University Electronic Theses, Dissertations & Projects

High-risk types of the human papillomavirus (HR-HPV) are the causative agents of nearly all cases of cervical cancer, as well as a significant number of head, neck, penile, vulvar and anal cancers. Like many other viruses with small genomes, HPV (~8 kb) utilizes numerous mechanisms to increase the capacity of its genome to encode the proteins necessary for successful completion of its infectious life cycle, including alternative splicing. Studies over the past few decades have focused intensively on the activities and roles of E6 proteins from HR-HPVs during the process of cellular transformation, clearly implicating E6 as a major transforming …

Effects Of Neonatal Dexamethasone On The Maturation And Endowment Of Cardiomyocytes, Maresha Gay

Loma Linda University Electronic Theses, Dissertations & Projects

Each year 1 in 9 infants are born preterm in the United States. Preterm infants have a host of complications associated with prematurity, including respiratory distress syndrome. Dexamethasone, a synthetic glucocorticoid is the ‘gold standard’ intervention in the treatment of preterm infants and mothers at risk of preterm birth because it promotes organ maturation, particularly the lungs and aids in surfactant production. However, a growing body of evidence suggests perinatal dexamethasone exposure is associated with health consequences later in life including increased risk of cardiovascular disease. Cardiomyocytes are the functional unit of the heart and are unique in that they …

Dietary Intake And Bio-Activation Of Nitrite And Nitrate In Newborn Infants, Jesica Ann Jones

Loma Linda University Electronic Theses, Dissertations & Projects

Nitrate and nitrite are commonly thought of as inert end products of nitric oxide (NO) oxidation, possibly carcinogenic food additives, or well-water contaminants. However, recent studies have shown that nitrate and nitrite play an important role in cardiovascular and gastrointestinal homeostasis through conversion back into NO via a physiological system involving enterosalivary recirculation, bacterial nitrate reductases, and enzyme-catalyzed or acidic reduction of nitrite to NO. The diet is a key source of nitrate in adults; however, infants ingest significantly less nitrate due to low concentrations in breast milk. In the mouth, bacteria convert nitrate to nitrite, which has gastro-protective effects. …

Acclimatization To High-Altitude, Long-Term Hypoxia Alters Bk Channel Structure And Function, Xiaoxiao Tao

Loma Linda University Electronic Theses, Dissertations & Projects

We examined the major possible mechanisms for the left shift of the BK channel I-V relationship in native basilar artery myocytes from the two LTH groups. These mechanisms included: differential expression of the accessary BK -1 subunit; differential phosphorylation of the BK subunit; and splice variation of the BK subunit. Using molecular cloning, heterologous expression, and patch-clamp electrophysiology techniques, we elucidated a mechanism that, at least in part, contributes to the differences we observed between channels from native normoxic and LTH myocytes.

Molecular Characterization And Inhibition Of Antibodies Elicited Against Galactosyltransferase Knockout Pig Xenografts, John M. Stewart

Loma Linda University Electronic Theses, Dissertations & Projects

On average, 21 people in the United States die every day while waiting for a transplantable organ. Moreover, at the end of 2014, nearly 130,000 additional individuals were still on the transplant waiting list. Xenotransplantation, the transplantation of cells and/or organs from a member of another species, is both a viable supplement for, and bridge to, allotransplantation. Pigs are the favored organ donor because they: 1) breed and grow rapidly, 2) can be genetically modified, and 3) present few ethical concerns. However, due in part to their phylogenetic distance, several barriers must be successfully overcome before clinical xenotransplantation can be …

Radiosensitization Of Head & Neck Carcinoma Cells By Linifanib, A Receptor Tyrosine Kinase Inhibitor, Heng-Wei Hsu

Loma Linda University Electronic Theses, Dissertations & Projects

Tumor angiogenesis is a hallmark of advanced cancers and promotes invasion and metastasis. Over 90% of head and neck squamous cell carcinomas (HNSCC) express angiogenic factors such as vascular endothelial growth factor (VEGF). Since radiotherapy is one of the most commonly used treatments for HNSCC, it is imperative to identify the interactions between antiangiogenic therapy and radiotherapy, and to develop combination therapy to improve clinical outcome. The mechanisms between antiangiogenic agents and ionizing radiation are complicated and involve many interactions between the vasculature, tumor stroma and tumor cells. The proliferation and metastasis of tumor cells rely on angiogenesis/blood vessel formation. …

Perinatal Nicotine Exposure And Programming Of Hie Sensitive Phenotype In Neonatal Rat Brains, Yong Li

Loma Linda University Electronic Theses, Dissertations & Projects

Large epidemiological and animal studies have revealed a clear association of adverse intrauterine environment with the increased risk of metabolic, cardiovascular and neurological diseases. Maternal smoking is the single most widespread perinatal insult in the world and has been associated with adverse pregnancy outcomes for mother, fetus and the newborn. Our study aims to test the hypothesis that perinatal nicotine exposure induces reprogramming of susceptibility to hypoxic ischemic brain injury in the immature brain, focusing on the roles of AT1R and/or AT2R and trying to reveal the underlying epigenetic mechanisms. Therefore, we established two rat models: perinatal nicotine exposure model …

Effect Of Maternal Hypoxia On The Cerebral And Cardiac Tissue Remodeling, Wenni Tong

Loma Linda University Electronic Theses, Dissertations & Projects

Large epidemiological studies and animal studies have indicated a clear association of adverse intrauterine environment with an increased incidence of low birth weight, perinatal mortality, and cardiovascular disease in later adult life. In humans, one of the most common stresses in utero is hypoxia. The goal of this project is to test the hypothesis that fetal hypoxia causes reprogramming of MMPs and TIMPs expression patterns and activities leading to aberrant brain and heart development in the fetuses and neonates. In the first part of project, we tested the hypothesis that maternal hypoxia increases the activity of MMPs and decreases the …

Influence Of Gender And Aerobic Training Background On Exercise-Induced Increase In Adiponectin, Pooja Pratap Mujumdar

Loma Linda University Electronic Theses, Dissertations & Projects

Adipose tissue secretes the adipokine, adiponectin (ADPN), which is insulinsensitizing, anti-inflammatory, and anti-atherogenic. Exercise training improves insulin sensitivity and lowers the risk of cardiovascular complications. As some of the metabolic effects of exercise training and ADPN overlap, exercise training has been proposed to increase ADPN. However, most single bout exercise, or short-term (ï‚£3 months) and constant-effort (fixed session duration, fixed number of sessions/week, and fixed intensity) exercise protocols do not produce increases in ADPN in untrained and trained cohorts. Furthermore, most exercise studies were conducted on male-female mixed gender cohorts or male/female single gender cohorts. As a result, no direct …

Effects Of Advancing Age On Er Calcium Regulation In Rat Superior Cervical Ganglia, Conwin Kodel Vanterpool

Loma Linda University Electronic Theses, Dissertations & Projects

Intracellular calcium ([Ca²⁺]i) release from endoplasmic reticulum (ER) stores plays an important role in cell signaling. These stores are rapidly refilled via voltage-gated calcium channels or spontaneously via store-operated calcium channels and subsequent pumping by ER Ca²⁺-ATPases. Calcium release is triggered by the activation of the ryanodine receptor (RyR) channels and their function is in part dependent on their expression. We analyzed the [Ca²⁺]i transients in fura 2-loaded superior cervical ganglion (SCG) cells from 6, 12, 20, and 24-month-old Fischer 344 rats for their ability to rapidly and spontaneously refill. For rapid refilling, the …

Cocaine Induces Apoptosis In Coronary Artery Endothelial Cells: Cellular And Molecular Mechanisms, Jiale He

Loma Linda University Electronic Theses, Dissertations & Projects

Cocaine abuse has been associated with numerous cardiovascular consequences, such as depressed myocardial contractility, elevated blood pressure, coronary artery vasoconstriction, and myocardial ischemia and infarction. The multifactorial effects of cocaine often contribute to its sympathomimetic function. However, the direct cytotoxic effects of cocaine on the cardiovascular system, especially vascular endothelium, and the cellular and molecular mechanisms remain unknown. The present study was designed to examine the general hypothesis that cocaine induces apoptosis of coronary artery endothelium by suppressing nitric oxide synthesis, stimulating cytochrome c release from mitochondria and subsequently activation of the caspases cascade, which lead to endothelial cell apoptosis. …

Effects Of Pycnogenol On Microsomal Cytochrome P450 Activity And Apoptosis, Huong Thu Huynh

Loma Linda University Electronic Theses, Dissertations & Projects

Phytochemicals are naturally-occurring compounds found in plants, many of which are consumed as nutritional supplements by humans. Pycnogenol is a mixture of flavonoid compounds extracted from bark of pine trees (Pinus maritima) and is commercially available in several different pharmaceutical preparations as a free radical scavenger.

Since few scientific studies have documented the pharmacologic effects of pycnogenol, our objective was to characterize the biological activity of pycnogenol. One study looked at the effects of pycnogenol on the three pathways of NNK metabolism: NNK reduction, N-oxidation and a-hydroxylation. NNK is a lung carcinogen. Lung and liver microsomes from 6 mo and …

The Effect Of Systemic Doxycycline On Alveolar Bone Loss Following Periradicular Surgery, G. Reed Cummings

Loma Linda University Electronic Theses, Dissertations & Projects

Studies have shown an average of 0.5 mm to over 1.0 mm of bone loss following full thickness flap reflection. Recent investigations have revealed that the tetracycline family of antibiotics can prevent bone loss. The purpose of this study was to determine the effect of systemic Doxycycline on crestal alveolar bone loss following periradicular surgery in Beagle dogs.

The experiment was divided into two phases. The first phase served as the control (Non-Doxycycline), the second phase as the experiment (Doxycycline). Full thickness flaps were reflected in the mandibular left or right quadrant (control side) of five Beagle dogs. Using a …

Effect Of Long-Term Hypoxia On Myocardial Alpha1- Receptors, Bihong T. Chen

Loma Linda University Electronic Theses, Dissertations & Projects

To determine the developmental changes in myocardial α₁-adrenergic receptor system, we employed [³H-Prazosin] binding technique to characterize α₁-adrenergic receptors in both fetal and adult sheep myocardial ventricular membrane preparations. Myocardial α₁-adrenergic receptor density (Bmax) declined during developmental process with both fetal left ventricle(LV) and fetal right ventricle(RV) having significantly more binding sites than respective adult ventricles. We also demonstrated that the positive inotropic response to the α₁-adrenergic agonist phenylephrine did not differ significantly between the fetal and adult ventricles.

The present study also investigated the effect of long-term high-altitude hypoxemia …

Role Of Cytochrome P-450 In Methemoglobin Formation By Primaquine With Hamster Liver Microsomes, Tommy L. Hicks

Loma Linda University Electronic Theses, Dissertations & Projects

The role of cytochrome P-450 in in vitro methemoglobin formation by primaquine was investigated through a series of experiments with golden-Syrian hamsters, treated before sacrificing with phenobarbital or 20-methylcholanthrene to increase the cytochrome P-450 content or with cobaltous chloride to cause its decrease. To determine the extent of induction in the liver microsomal cytochrome P-450-dependent mixed-function oxidases, cytochrome P-450 content and formaldehyde from the 0-demethylation of p-nitroanisole were measured. A 90% increase occurred in cytochrome P-450 content with phenobarbital pretreatment and an increase of 102% was observed in p-nitroanisole 0-demethylation. Formaldehyde from primaquine increased 64%. The methylcholanthrene treatment produced a …

An Anesthetic Technique Utilizing Innovar, Fentanyl, And Methohexital Sodium For Outpatient Oral Surgery, Fredric D. Haerich

Loma Linda University Electronic Theses, Dissertations & Projects

A study of 800 patients ranging in age from seven to one hundred years was conducted in the development of an anesthetic technique which combines the desirable qualities of a neuroleptic agent with the requirements of an outpatient oral surgical anesthetic. These requirements included rapidity of onset, effectiveness of action, ease of controlling duration, and rapid postoperative recovery.

Patients who were cleared medically for outpatient procedures were given Innovar 1.5 cc/150 lb of body weight, atropine 0.4 mg, and fentanyl 1.0 cc/150 lb of body weight as an initial dose within 30-45 seconds in a D5W drip by means of …

A Comparative In Vitro Metabolic Study Of Certain Pesticidal Phenyl N-Methyl-Carbamates, Larry A. Wheeler

Loma Linda University Electronic Theses, Dissertations & Projects

Two critical parameters in the evaluation of the toxicological hazards of the use of carbamate pesticides are: (1) a rapid, sensitive, and precise analytical method of identification of the carbamate and its metabolites; and (2) their metabolism. A method in this study was developed whereby various carbamates and their metabolites could be chromatographed in the gaseous phase. Also, a comparative in vitro study of 15,000 g liver supernatants from human, rat, and dog was performed. Additional tissues investigated for metabolic activity toward the carbamates, Zectran and Mesurol, were kidney (from the dog only) and various blood fractions (red blood cells, …