Medical Biochemistry Commons^™

Truncation Of Type Iv Pilin Induces Mucoidy In Pseudomonas Aeruginosa Strain Pao579, T. Ryan Withers, F. Heath Damron, Yeshi Yin, Hongwei D. Yu

Biochemistry and Microbiology

Pseudomonas aeruginosa is a Gram negative, opportunistic pathogen that uses the overproduction of alginate, a surface polysaccharide, to form biofilms in vivo. Overproduction of alginate, also known as mucoidy, affords the bacterium protection from the host's defenses and facilitates the establishment of chronic lung infections in individuals with cystic fibrosis. Expression of the alginate biosynthetic operon is primarily controlled by the alternative sigma factor AlgU (AlgT/σ²²). In a nonmucoid strain, AlgU is sequestered by the transmembrane antisigma factor MucA to the cytoplasmic membrane. AlgU can be released from MucA via regulated intramembrane proteolysis by proteases AlgW and MucP …

Stem Cell Transplantation Increases Antioxidant Effects In Diabetic Mice, Ming Li, Luca Vanella, Yuming Zhang, Ming Shi, Takashi Takaki, Joseph I. Shapiro M.D., Susuma Ikehera

Biochemistry and Microbiology

Intra bone marrow-bone marrow transplantation (IBM- BMT) + thymus transplantation (TT) has been shown to reduce the incidence of graft versus host disease (GVHD) and restore donor-derived T cell function. In addition, an increase in insulin sensitivity occurred in db/db mice after IBM-BMT+TT treatment. Heme oxygenase (HO)-1 is a stress inducible enzyme which exert antioxidant, antiapoptotic, and immune-modulating properties. We examined whether IBM-BMT+TT could modulate the expression of HO-1 in the kidneys of db/db mice. Six-week-old db/db mice with blood glucose levels higher than 250 mg/dl were treated with IBM-BMT+TT. Six weeks later, the db/db mice showed decreased body weight, …

Domain Requirements For The Diverse Immune Regulatory Functions Of Foxp3, Wei-Ping Zeng, Vincent E. Sollars, Andrea Del Pilar Belalcazar

Biochemistry and Microbiology

Foxp3 is responsible for the major immunological features of Treg cells, including hypoproliferation in vitro, immune suppression of conventional T cells and resistance to Th2 cell differentiation. In addition to the Forkhead domain, the Foxp3 protein contains the N-terminal, zinc finger and leucine zipper domains. To understand how these domains contribute to Foxp3 functions, we systematically compared the roles of these domains in determining the 3 major immunological features of Treg cells. We designed a bridge-mediated mutagenesis method to generate Foxp3 mutants with complete deletion of each of the domains. CD4 T cells expressing the Foxp3 mutant with deletion of …

Capsaicin Displays Anti-Proliferative Activity Against Human Small Cell Lung Cancer In Cell Culture And Nude Mice Models Via The E2f Pathway, Kathleen C. Brown, Theodore R. Witte, W. Elaine Hardman, Haitao Luo, Yi C. Chen, A. Betts Carpenter, Jamie K. Lau, Piyali Dasgupta

Biochemistry and Microbiology

Background: Small cell lung cancer (SCLC) is characterized by rapid progression and low survival rates. Therefore, novel therapeutic agents are urgently needed for this disease. Capsaicin, the active ingredient of chilli peppers, displays antiproliferative activity in prostate and epidermoid cancer in vitro. However, the anti-proliferative activity of capsaicin has not been studied in human SCLCs. The present manuscript fills this void of knowledge and explores the anti-proliferative effect of capsaicin in SCLC in vitro and in vivo.

Methodology/Principal Findings: BrdU assays and PCNA ELISAs showed that capsaicin displays robust anti-proliferative activity in four human SCLC cell lines. Furthermore, capsaicin potently …

Rbc And Wbc Fatty Acid Composition Following Consumption Of An Omega 3 Supplement: Lessons For Future Clinical Trials, Theodore R. Witte, Alexander J. Salazar, Oscar F. Ballester, W. Elaine Hardman

Biochemistry and Microbiology

Background: Results from increasing numbers of in vitro and in vivo studies have demonstrated that omega 3 fatty acids incorporated in cell culture media or in the diet of the animals can suppress the growth of cancers. When human clinical trials are initiated to determine the ability of omega 3 fatty acids to alter growth or response to chemotherapeutic interventions of cancers, it will be essential to determine the omega 3 intake of individuals in the trial to determine compliance with consumption of the supplement and to correlate with endpoints of efficacy. We wondered if the fatty acid composition of …

Dietary Canola Oil Suppressed Growth Of Implanted Mda-Mb 231 Human Breast Tumors In Nude Mice, W. Elaine Hardman

Biochemistry and Microbiology

Long chain omega 3 (n-3) fatty acids, eicosapentaenoic (EPA) and/or docosahexaenoic acid (DHA), have been shown to suppress growth of most cancer cells. In vivo, alpha linolenic acid (ALA, 18:3n-3) can be converted to EPA or DHA. We hypothesized that substituting canola oil (10% ALA) for the corn oil (1% ALA) in the diet of cancer bearing mice would slow tumor growth by increasing n-3 fatty acids in the diet. Sixty nude mice received MDA-MB 231 human breast cancer cells and were fed a diet containing 8% w/w corn oil until the mean tumor volume was 60 mm ³ . …

Therapeutic Electromagnetic Field (Temf) And Gamma Irradiation On Human Breast Cancer Xenograft Growth, Angiogenesis And Metastasis, Ivan L. Cameron, Luzhe Sun, Nicholas Short, W. Elaine Hardman, C. Douglas Williams

Biochemistry and Microbiology

Background

The effects of a rectified semi-sinewave signal (15 mT amplitude, 120 pulses per second, EMF Therapeutics, Inc.) (TEMF) alone and in combination with gamma irradiation (IR) therapy in nude mice bearing a human MDA MB231 breast cancer xenograft were tested. Green fluorescence protein transfected cancer cells were injected into the mammary fat pad of young female mice. Six weeks later, mice were randomly divided into four treatment groups: untreated controls; 10 minute daily TEMF; 200 cGy of IR every other day (total 800 cGy); IR plus daily TEMF. Some mice in each group were euthanized 24 hours after the …

Endothelial Cell Pseudopods And Angiogenesis Of Breast Cancer Tumors, Ivan L. Cameron, Nicholas Short, Luzhe Sun, W. Elaine Hardman

Biochemistry and Microbiology

Background

A neoplastic tumor cannot grow beyond a millimeter or so in diameter without recruitment of endothelial cells and new blood vessels to supply nutrition and oxygen for tumor cell survival. This study was designed to investigate formation of new blood vessels within a human growing breast cancer tumor model (MDA MB231 in mammary fat pad of nude female mouse). Once the tumor grew to 35 mm³, it developed a well-vascularized capsule. Histological sections of tumors greater than 35 mm³were stained with PAS, with CD-31 antibody (an endothelial cell maker), or with hypoxia inducible factor 1α …

Dietary Omega-3 Fatty Acids And Ionizing Irradiation On Human Breast Cancer Xenograft Growth And Angiogenesis, W. Elaine Hardman, Luzhe Sun, Nicholas Short, Ivan L. Cameron

Biochemistry and Microbiology

Background

The effects of an omega-3 (n-3) fatty acid enriched diet alone and in combination with gamma irradiation (IR) therapy in nude mice bearing a human MDA-MB231 breast cancer xenograft were tested. The cancer cells were injected into the mammary fat pad of young female mice. Six weeks later, mice were randomly divided into two diet groups: 1) mice with 10% corn oil (rich in omega 6 fatty acids) in their food, 2) mice consuming a 10% fat diet that was enriched in n-3 fatty acids. After two weeks on the diet, treatment with 200 cGy of IR every second …

Waddington’S Widget: Hsp90 And The Inheritance Of Acquired Characters, Douglas M. Ruden, Mark D. Garfinkel, Vincent E. Sollars, Xiangyi Lu

Biochemistry and Microbiology

Conrad Waddington published an influential model for evolution in his 1942 paper, Canalization of Development and Inheritance of Acquired Characters. In this classic, albeit controversial, paper, he proposed that an unknown mechanism exists that conceals phenotypic variation until the organism is stressed. Recent studies have proposed that the highly conserved chaperone Hsp90 could function as a “capacitor,” or an “adaptively inducible canalizer,” that masks silent phenotypic variation of either genetic or epigenetic origin. This review will discuss evidence for, and arguments against, the role of Hsp90 as a capacitor for morphological evolution, and as a key component of what …

High Dietary Level Of Synthetic Vitamin E On Lipid Peroxidation, Membrane Fatty Acid Composition And Cytotoxicity In Breast Cancer Xenograft And In Mouse Host Tissue, Ivan L. Cameron, Jesus Munoz, Christopher J. Barnes, W. Elaine Hardman

Biochemistry and Microbiology

Background

d-α-tocopherol is a naturally occurring form of vitamin E not previously known to have antitumor activity. Synthetic vitamin E (sE) is a commonly used dietary supplement consisting of a mixture of d-α-tocopherol and 7 equimolar stereoisomers. To test for antilipid peroxidation and for antitumor activity of sE supplementation, two groups of nude mice bearing a MDA-MB 231 human breast cancer tumor were fed an AIN-76 diet, one with and one without an additional 2000 IU/kg dry food (equivalent to 900 mg of all-rac-α-tocopherol or sE). This provided an intake of about 200 mg/kg body weight per day. The mice …

Regulation Of Retinoic Acid Receptor Α By Protein Kinase C In B16 Mouse Melanoma Cells, Goran Boskovic, Dinakar Desai, Richard M. Niles

Biochemistry and Microbiology

We have previously found that retinoic acid stimulates the expression of protein kinase Cα (PKC) in B16 mouse melanoma cells. Because it has been reported that PKC can phosphorylate retinoic acid receptor (RAR) and alter its function, we determined whether changes in the level and/or activity of PKC could affect the expression or function of the RAR in B16 melanoma. Using in vivophosphorylation and band shift techniques, we could not demonstrate that altering PKC activity and/or protein level changed thein vivo phosphorylation of RARα. However activation of PKC resulted in increased RARα protein. Increased receptor protein correlated with …

Therapeutic Electromagnetic Field Effects On Angiogenesis And Tumor Growth, C. Douglas Williams, Marko S. Markov, W. Elaine Hardman, Ivan L. Cameron

Biochemistry and Microbiology

Background: A new approach to cancer therapy based on the application of therapeutic electromagnetic fields (TEMF) has been developed by EMF Therapeutics, Inc., Chattanooga, TN, USA. This study was designed to assess the effect of TEMF on tumor vascularization and growth of murine 16/C mammmary adenocarcinoma cells in C3H/HeJ mice.

Materials and Methods: Implanted tumors were allowed to grow for seven days until the tumor volume reached 100 mm3 before treatment was started. Mice (20 per control, 10 per EMF exposed group) received treatment (10 minutes per day with 0, 10 mT, 15 mT or 20 mT) with a 120 …

Immunologic Effects Of Gliotoxin In Rats: Mechanisms For Prevention Of Autoimmune Diabetes Mellitus, Honggang Liu, Susan H. Jackman, Henry Driscoll, Bryan Larsen

Biochemistry and Microbiology

Various fungal products, such as gliotoxin (GT), have immunomodulating activity, a fact exploited previously by our group for prevention of autoimmune diabetes mellitus in BB/Wor rats. To understand better the immunologic effects in GT-treated rats, splenocytes from 65-day-old prediabetic diabetes-prone rats were phenotypically characterized after chronic treatment with GT. A parallel study examined the direct effects of GT on splenocyte preparations incubated with the mycotoxin. In vitro treatment of splenocytes with GT revealed relative decreases in CD4+ and increases in CD8+ T-cell subsets, whereas in vivo treatment with GT did not result in detectable alterations in relative CD4+ and CD8+ …

Effect Of Receptor-Selective Retinoids On Growth And Differentiation Pathways In Mouse Melanoma Cells, Sejal H. Desai, Goran Boskovic, Linda L. Eastham, Marcia Dawson, Richard M. Niles

Biochemistry and Microbiology

Treatment of B16 mouse melanoma cells with all-trans-retinoic acid (ATRA) results in inhibition of cell proliferation and induction of differentiation. Accompanying these events is an induction of retinoic acid receptor β (RARβ) expression, an increase in protein kinase Cα (PKCα) expression, and enhanced activator protein-1 (AP-1) transcriptional activity. These cells express nuclear RARα and RARγ and nuclear retinoid X receptors (RXR) α and β constitutively. We tested the ability of receptor-selective retinoids to induce the biochemical changes found in ATRA-treated melanoma cells and also tested their effectiveness in decreasing anchorage-dependent and -independent growth. The RXR-selective ligand (2E,4E)-6-(5,6,7,8-tetrahydro-3,5,5,8,8-pentamethyl-2-naphthalenyl)-3,7-dimethyl-2,4,6-octatrienoic acid (SR11246) was …