Medical Sciences Commons^™

Identification Of A Second Mimicry Epitope From Acanthamoeba Castellanii That Induces Cns Autoimmunity By Generating Cross-Reactive T Cells For Mbp 89–101 In Sjl Mice, Chandirasegaran Massilamany, Oluwatoyin A. Asojo, Arunakumar Gangaplara, David J. Steffen, Jay Reddy

Jay Reddy Publications

We had previously reported that Acanthamoeba castellanii (ACA) contains a mimicry epitope for proteolipid protein 139–151 capable of inducing central nervous system (CNS) autoimmunity in SJL/J mice. We now present evidence that ACA also contains a mimicry epitope for myelin basic protein (MBP) 89–101, a derivative from amoebic nicotinamide adenine dinucleotide dehydrogenase subunit 2 (NAD). The epitope, NAD 108–120, contains a discontinuous stretch of six amino acids in the core region (VVFFKNIILIGFL) sharing 46% identity with MBP 89–101 (VHFFKNIVTPRTP; identical residues are underlined). SJL mice immunized with NAD 108–120 develop encephalomyelitis similar to the disease induced by the cognate peptide. …

Cellular Inhibitor Of Apoptosis 1 (Ciap-1) Degradation By Caspase 8 During Tnf-Related Apoptosis-Inducing Ligand (Trail)-Induced Apoptosis., Maria Eugenia Guicciardi, Justin L. Mott, Steven F. Bronk, Satoshi Kurita, Christian D. Fingas, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

TNF-related apoptosis-inducing ligand (TRAIL) is a potential chemotherapeutic agent with high selectivity for malignant cells. Many tumors, however, are resistant to TRAIL cytotoxicity. Although cellular inhibitors of apoptosis 1 and 2 (cIAP-1 and -2) are often over-expressed in cancers, their role in mediating TRAIL resistance remains unclear. Here, we demonstrate that TRAIL-induced apoptosis of liver cancer cells is associated with degradation of cIAP-1 and X-linked IAP (XIAP), whereas cIAP-2 remains unchanged. Lower concentrations of TRAIL causing minimal or no apoptosis do not alter cIAP-1 or XIAP protein levels. Silencing of cIAP-1 expression, but not XIAP or cIAP-2, as well as …

Mir-27b*, An Oxidative Stress-Responsive Microrna Modulates Nuclear Factor-Kb Pathway In Raw 264.7 Cells, Sivasubramani Thulasingam, Chandirasegaran Massilamany, Arunakumar Gangaplara, Hongjiu Dai, Shahlo Yarbaeva, Sakthivel Subramaniam, Jean-Jack Riethoven, James Eudy, Marjorie F. Lou, Jay Reddy

Jay Reddy Publications

Reactive oxygen species (ROS) produced in macrophages is critical for microbial killing, but they also take part in inflammation and antigen presentation functions. MicroRNAs (miRNAs) are endogenous regulators of gene expression, and they can control immune responses. To dissect the complex nature of ROS-mediated effects in macrophages, we sought to characterize miRNAs that are responsive to oxidative stress-induced with hydrogen peroxide (H₂O₂) in the mouse macrophage cell line, RAW 264.7. We have identified a set of unique miRNAs that are differentially expressed in response to H₂O₂. These include miR-27a*, miR-27b*, miR-29b*, miR-24-2*, …

Identification Of A Second Mimicry Epitope From Acanthamoeba Castellanii That Induces Cns Autoimmunity By Generating Cross-Reactive T Cells For Mbp 89–101 In Sjl Mice, Chandirasegaran Massilamany, Oluwatoyin A. Asojo, Arunakumar Gangaplara, David J. Steffen, Jay Reddy

Jay Reddy Publications

We had previously reported that Acanthamoeba castellanii (ACA) contains a mimicry epitope for proteolipid protein 139–151 capable of inducing central nervous system (CNS) autoimmunity in SJL/J mice. We now present evidence that ACA also contains a mimicry epitope for myelin basic protein (MBP) 89–101, a derivative from amoebic nicotinamide adenine dinucleotide dehydrogenase subunit 2 (NAD). The epitope, NAD 108–120, contains a discontinuous stretch of six amino acids in the core region (VVFFKNIILIGFL) sharing 46% identity with MBP 89–101 (VHFFKNIVTPRTP; identical residues are underlined). SJL mice immunized with NAD 108–120 develop encephalomyelitis similar to the disease induced by the cognate peptide. …

The Role Of The Nr4a Orphan Nuclear Receptor Nor1 In Vascular Cells And Atherosclerosis, Yue Zhao

University of Kentucky Doctoral Dissertations

The neuron-derived orphan receptor 1 (NOR1) belongs to the NR4A nuclear receptor subfamily. As an immediate early response gene, NOR1 is rapidly induced by a broad spectrum of physiological and pathological signals. Functional studies demonstrate NOR1 as a constitutively active ligand-independent nuclear receptor whose transcriptional activity is dependent on both expression level and posttranslational modifications. To date, an increasing number of studies have demonstrated a pivotal role of NOR1 in the transcriptional control of metabolism and the development of cardiovascular diseases.

In this dissertation, we demonstrate NOR1 expression in endothelial cells and sub-endothelial cells of human atherosclerotic lesions. In response …

Protein Modification By Arginylation, Hideko Kaji, Akira Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

The modification of protein by arginine catalyzed by arginyltransferases (ATE1) described by the Kashina group in this issue shows that arginylation of protein occurs widely in biology and is being recognized as a key regulatory reaction such as phosphorylation of proteins (Wang et al., 2011).

Carhsp1 Is Required For Effective Tumor Necrosis Factor Alpha Mrna Stabilization And Localizes To Processing Bodies And Exosomes, Jason R. Pfeiffer, Bethany L. Mcavoy, Ryan E. Fecteau, Kristen M. Deleault, Seth A. Brooks

Dartmouth Scholarship

Tumor necrosis factor alpha (TNF-α) is a critical mediator of inflammation, and its production is tightly regulated, with control points operating at nearly every step of its biosynthesis. We sought to identify uncharacterized TNF-α 3' untranslated region (3'UTR)-interacting proteins utilizing a novel screen, termed the RNA capture assay. We identified CARHSP1, a cold-shock domain-containing protein. Knockdown of CARHSP1 inhibits TNF-α protein production in lipopolysaccharide (LPS)-stimulated cells and reduces the level of TNF-α mRNA in both resting and LPS-stimulated cells. mRNA stability assays demonstrate that CARHSP1 knockdown decreases TNF-α mRNA stability from a half-life (t(1/2)) of 49 min to a t(1/2) …

A Smac Mimetic Reduces Tnf Related Apoptosis Inducing Ligand (Trail)-Induced Invasion And Metastasis Of Cholangiocarcinoma Cells., Christian D. Fingas, Boris R.A. Blechacz, Rory L. Smoot, Maria E. Guicciardi, Justin L. Mott, Steve F. Bronk, Nathan W. Werneburg, Alphonse E. Sirica, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

UNLABELLED: Cholangiocarcinoma (CCA) cells paradoxically express tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a death ligand that, failing to kill CCA cells, instead promotes their tumorigenicity and especially the metastatic behaviors of cell migration and invasion. Second mitochondria-derived activator of caspase (smac) mimetics are promising cancer therapeutic agents that enhance proapoptotic death receptor signaling by causing cellular degradation of inhibitor of apoptosis (IAP) proteins. Our aim was to examine the in vitro and in vivo effects of the smac mimetic JP1584 in CCA. Despite JP1584-mediated loss of cellular inhibitor of apoptosis-1 (cIAP-1) and cIAP-2, TRAIL failed to induce apoptosis in KMCH-1, …

Transcriptional Suppression Of Mir-29b-1/Mir-29a Promoter By C-Myc, Hedgehog, And Nf-Kappab., Justin L. Mott, Satoshi Kurita, Sophie C. Cazanave, Steven F. Bronk, Nathan W. Werneburg, Martin E. Fernandez-Zapico

Journal Articles: Biochemistry & Molecular Biology

MicroRNAs regulate pathways contributing to oncogenesis, and thus the mechanisms causing dysregulation of microRNA expression in cancer are of significant interest. Mature mir-29b levels are decreased in malignant cells, and this alteration promotes the malignant phenotype, including apoptosis resistance. However, the mechanism responsible for mir-29b suppression is unknown. Here, we examined mir-29 expression from chromosome 7q32 using cholangiocarcinoma cells as a model for mir-29b downregulation. Using 5' rapid amplification of cDNA ends, the transcriptional start site was identified for this microRNA locus. Computational analysis revealed the presence of two putative E-box (Myc-binding) sites, a Gli-binding site, and four NF-kappaB-binding sites …

Noxa Mediates Hepatic Stellate Cell Apoptosis By Proteasome Inhibition., Ivette M. Sosa Seda, Justin L. Mott, Yuko Akazawa, Fernando J. Barreyro, Steven F. Bronk, Scott H. Kaufmann, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

Aim: Induction of hepatic stellate cell (HSC) apoptosis is a viable therapeutic strategy to reduce liver fibrogenesis. Although BH3-only proteins of the Bcl-2 family trigger pro-apoptotic pathways, the BH3-only proteins mediating HSC apoptosis have not been well defined. Our aim, using proteasome inhibition as a model to induce HSC apoptosis, was to examine the BH3-only proteins contributing to cell death of this key liver cell subtype. Methods: Apoptosis was induced by treating LX-2 cells, an immortalized human hepatic stellate cell line, and primary rat stellate cells with the proteasome inhibitor MG-132. Results: Treatment with proteasome inhibitors increased expression of Noxa …

Ribosome Recycling Step In Yeast Cytoplasmic Protein Synthesis Is Catalyzed By Eef3 And Atp., Shinya Kurata, Klaus H Nielsen, Sarah F Mitchell, Jon R Lorsch, Akira Kaji, Hideko Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

After each round of protein biosynthesis, the posttermination complex (PoTC) consisting of a ribosome, mRNA, and tRNA must be disassembled into its components for a new round of translation. Here, we show that a Saccharomyces cerevisiae model PoTC was disassembled by ATP and eukaryotic elongation factor 3 (eEF3). GTP or ITP functioned with less efficiency and adenosine 5gamma'-(beta,gamma-imido)triphosphate did not function at all. The k(cat) of eEF3 was 1.12 min(-1), which is comparable to that of the in vitro initiation step. The disassembly reaction was inhibited by aminoglycosides and cycloheximide. The subunits formed from the yeast model PoTC remained separated …

Glycan Shielding Of The Influenza Virus Hemagglutinin Elicits Evasion Of The Adaptive Immune Response And T-Cell-Driven Pathology, Keith C. Wanzeck

Theses and Dissertations (ETD)

Three separate influenza pandemics have emerged in the human population since 1918, each characterized by viruses that lack N-linked glycosylation sites on the globular head of the hemagglutinin protein. In contrast, recent non-pandemic isolates have acquired such sites. Here we constructed isogenic viruses containing differing numbers of additional N-linked glycosylation sites to assess the impact on the host immune response. These studies show that mice infected with a glycosylated virus remain susceptible to challenge with a non-glycosylated virus, glycosylated viruses elicit an inferior immune response, and in this context T-cell pathology and death may occur. We conclude from these data …

Mbp-1 Upregulates Mir-29b That Represses Mcl-1, Collagens, And Matrix-Metalloproteinase-2 In Prostate Cancer Cells., Robert Steele, Justin L. Mott, Ratna B. Ray

Journal Articles: Biochemistry & Molecular Biology

c-myc promoter binding protein (MBP-1) is a multi-functional protein known to regulate expression of targets involved in the malignant phenotype. We have previously demonstrated that exogenous expression of MBP-1 inhibits prostate tumor growth, although the mechanism of growth inhibition is not well understood. We hypothesized that MBP-1 may modulate microRNA (miRNA) expression for regulation of prostate cancer cell growth. In this study, we demonstrated that exogenous MBP-1 upregulates miR-29b by 5-9 fold in prostate cancer cells as measured by real-time quantitative reverse transcription-PCR. Subsequent studies indicated that exogenous expression of miR-29b inhibited Mcl-1, COL1A1, and COL4A1. Further, a novel target …

Palmitoleate Attenuates Palmitate-Induced Bim And Puma Up-Regulation And Hepatocyte Lipoapoptosis., Yuko Akazawa, Sophie Cazanave, Justin L. Mott, Nafisa Elmi, Steven F. Bronk, Shigeru Kohno, Michael R. Charlton, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND & AIMS: Saturated free fatty acids induce hepatocyte lipoapoptosis. This lipotoxicity involves an endoplasmic reticulum stress response, activation of JNK, and altered expression and function of Bcl-2 proteins. The mono-unsaturated free fatty acid palmitoleate is an adipose-derived lipokine which suppresses free fatty acid-mediated lipotoxicity by unclear mechanisms. Herein we examined the mechanisms responsible for cytoprotection.

METHODS: We employed isolated human and mouse primary hepatocytes, and the Huh-7 and Hep 3B cell lines for these studies. Cells were incubated in presence and absence of palmitate (16:0), stearate (18:0), and or palmitoleate (16:1, n-7).

RESULTS: Palmitoleate significantly reduced lipoapoptosis by palmitate …

P66shc--A Longevity Redox Protein In Human Prostate Cancer Progression And Metastasis : P66shc In Cancer Progression And Metastasis., Mythilypriya Rajendran, Paul Thomes, Li Zhang, Suresh Veeramani, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

p66Shc, a 66 kDa proto-oncogene Src homologous-collagen homologue (Shc) adaptor protein, is classically known in mediating receptor tyrosine kinase signaling and recently identified as a sensor to oxidative stress-induced apoptosis and as a longevity protein in mammals. The expression of p66Shc is decreased in mice and increased in human fibroblasts upon aging and in aging-related diseases, including prostate cancer. p66Shc protein level correlates with the proliferation of several carcinoma cells and can be regulated by steroid hormones. Recent advances point that p66Shc protein plays a role in mediating cross-talk between steroid hormones and redox signals by serving as a common …

Electrospun Nanofibers For Neural Tissue Engineering, Jingwei Xie, Matthew R. Macewan, Andrea G. Schwartz, Younan Xia

MIIR Faculty Research

Biodegradable nanofibers produced by electrospinning represent a new class of promising scaffolds to support nerve regeneration. We begin with a brief discussion on electrospinning of nanofibers and methods for controlling the structure, porosity, and alignment of the electrospun nanofibers. The methods include control of the nanoscale morphology and microscale alignment for the nanofibers, as well as the fabrication of macroscale, three-dimensional tubular structures. We then highlight recent studies that utilize electrospun nanofibers to manipulate biological processes relevant to nervous tissue regeneration, including stem cell differentiation, guidance of neurite extension, and peripheral nerve injury treatments. The main objective of this feature …

An Epitope From Acanthamoeba Castellanii That Cross-React With Proteolipid Protein 139-151-Reactive T Cells Induces Autoimmune Encephalomyelitis In Sjl Mice, Chandirasegaran Massilamany, David Steffan, Jay Reddy

Jay Reddy Publications

We report here that an epitope (aa, 83-95) derived from Acanthamoeba castellanii (ACA) induces clinical signs of experimental autoimmune encephalomyelitis (EAE) in SJL/J mice reminiscent of the disease induced with myelin proteolipid protein (PLP) 139-151. By using IA^s/tetramers, we demonstrate that both ACA 83-95 and PLP 139-151 generate antigen-specific cross-reactive CD4 T cells and the T cells secrete identical patterns of cytokines and induce EAE with a similar severity. These results may provide insights into the pathogenesis of multiple sclerosis and ACA-induced granulomatous encephalitis.

Effect Of Dietary Folate Restriction On Colon Carcinogenesis In Dna Polymerase Β Haploinsufficient Mice, Lisa F. Ventrella Lucente

Wayne State University Dissertations

The data presented in this research is central to establishing the role that the base excision repair pathway (BER) plays in the development and progression of colon cancer when dietary folate is deficient. Both cellular folate restriction and BER deficiencies have been shown to result in the accumulation of endogenous damage and lesions that could eventually develop into carcinogenesis. In this study, a dietary folate deficiency (FD) resulted in a significant increase in aberrant crypt foci (ACF) formation and triggered liver tumorogenesis in wildtype (WT) animals, as did a BER deficiency in DNA polymerase Β haploinsufficient (Β-pol+/-) mice exposed to …

Ligand-Protein Interactions Of Inhibitors With Dengue Virus Type 2 Serine Protease : A Structural Study., Rozana Othman

Student Works (2010-2019)

Dengue is a serious infectious disease that is endemic in over 100 countries. There has been an estimate of 50 million infection per year globally, with more than 2.5 billion people are at risk for epidemic transmission. Two principal illnesses associated with dengue are Dengue Fever (DF) and Dengue Haemorrhagic Fever (DHF). To date, there is no licensed vaccine or therapeutic drug available for these illnesses, although there have been reports of some vaccine candidates in clinical trials. Treatments have only been supportive thus far. This thesis describes part of our ongoing effort to search for a lead therapeutic agent …

Imaging Spontaneous Mmtvneu Transgenic Murine Mammary Tumors: Targeting Metabolic Activity Versus Genetic Products., Mathew L Thakur, Devakumar Devadhas, Kaijun Zhang, Richard G Pestell, Chenguang Wang, Peter Mccue, Eric Wickstrom

Department of Radiology Faculty Papers

INTRODUCTION: Despite the great strides made in imaging breast cancer (BC) in humans, the current imaging modalities miss up to 30% of BC, do not distinguish malignant lesions from benign ones, and require histologic examinations for which invasive biopsy must be performed. Annually in the United States, approximately 5.6 million biopsies find benign lesions. More than 50% of human BCs overexpress cyclin D1, and all BCs exhibit VPAC1 oncogene products. Together, these gene products may provide an excellent biomarker for the early and accurate detection of BC. We have evaluated 4 biologically active peptide analogs that have high affinity for …

Activation Of Tumor Cell Death Program By Targeting The Ubiquitin-Proteasome Pathway: Significance In Cancer Treatment And Prevention, Michael Joseph Frezza

Wayne State University Dissertations

ACTIVATION OF TUMOR CELL DEATH PROGRAM BY TARGETING THE UBIQUITIN-PROTEASOME PATHWAY: SIGNIFICANCE IN CANCER TREATMENT AND PREVENTION

by

MICHAEL FREZZA

August 2010

Advisor: Dr. Q. Ping Dou

Major: Cancer Biology

Degree: Doctor of Philosophy

The ubiquitin-proteasome pathway serves as a quality control mechanism to regulate the degradation of intracellular proteins involved in a wide array of cellular processes including tumorigeneis. Thus targeting key features of protein turnover responsible for the growth and proliferation of cancer have emerged as a favorable approach in cancer therapy. Both in vitro and in vivo experimental and clinical results have demonstrated the potential use of …

Immunomodulatory Effect Of Host And Fungal Eicosanoids During Host-Pathogen Interactions With Candida Albicans, Gitanjali Kundu

Wayne State University Dissertations

Candida albicans, an opportunistic fungal pathogen, poses a significant clinical threat to immunocompromised patients. Diseases associated with this fungus ranges from superficial mucosal infection to life-threatening systemic candidiasis. The mechanisms by which Candida persists at mucosal surfaces in the face of an adaptive response are unclear. Candida produces immunomodulatory oxylipins that cross-react functionally with host eicosanoids, which are considered to play important role in regulating innate and adaptive immune responses. Our objective was to characterize the role of prostaglandins produced by the host and this fungus during host pathogen interactions, both in vitro with dendritic cells (DCs) and macrophages, and …

Recent Advances On Skin-Resident Stem/Progenitor Cell Functions In Skin Regeneration, Aging And Cancers And Novel Anti-Aging And Cancer Therapies., Murielle Mimeault, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Recent advances in skin-resident adult stem/progenitor cell research have revealed that these immature and regenerative cells with a high longevity provide critical functions in maintaining skin homeostasis and repair after severe injuries along the lifespan of individuals. The establishment of the functional properties of distinct adult stem/progenitor cells found in skin epidermis and hair follicles and extrinsic signals from their niches, which are deregulated during their aging and malignant transformation, has significantly improved our understanding on the etiopathogenesis of diverse human skin disorders and cancers. Particularly, enhanced ultraviolet radiation exposure, inflammation and oxidative stress and telomere attrition during chronological aging …

High-Density Screening Reveals A Different Spectrum Of Genomic Aberrations In Chronic Lymphocytic Leukemia Patients With ‘Stereotyped’ Ighv3-21 And Ighv4-34 B-Cell Receptors, Millaray Marincevic, Nicola Cahill, Rebeqa Gunnarsson, Anders Isaksson, Mahmoud Mansouri, Hanna Göransson, Markus Rasmussen, Mattias Jansson, Fergus Ryan, Karin Karlsson, Hans-Olov Adami, Fred Davi, Jesper Jurlander, Gunnar Juliusson, Kostas Stamatopoulos, Richard Rosenquist

Articles

Background The existence of multiple subsets of chronic lymphocytic leukemia expressing ‘stereotyped’ Bcell receptors implies the involvement of antigen(s) in leukemogenesis. Studies also indicate that ‘stereotypy’ may influence the clinical course of patients with chronic lymphocytic leukemia, for example, in subsets with stereotyped IGHV3-21 and IGHV4-34 B-cell receptors; however, little is known regarding the genomic profile of patients in these subsets. Design and Methods We applied 250K single nucleotide polymorphism-arrays to study copy-number aberrations and copy-number neutral loss-of-heterozygosity in patients with stereotyped IGHV3-21 (subset #2, n=29), stereotyped IGHV4-34 (subset #4, n=17; subset #16, n=8) and non-subset #2 IGHV3-21 (n=13) and …

Molecular And Therapeutic Implications Of Notch1 Signaling In Pediatric T-Cell Acute Lymphoblastic Leukemia, Amanda Larson Gedman

Wayne State University Dissertations

T-cell acute lymphoblastic leukemia (T-ALL) accounts for 15% of pediatric ALL cases and is associated with early relapse and inferior outcome. The poorer prognosis of T-ALL compared to B-precursor ALL may in part reflect the lack of unique features on which to base therapy. NOTCH1 mutations are of particular interest since these were reported in 37-71% of T-ALLs. The prognostic value of NOTCH1 mutations remains controversial as both favorable and unfavorable associations were reported, whereas in other studies, there were no associations between NOTCH1 mutations and treatment outcome. We explored the impact of mutations in NOTCH1, FBW7 and PTEN on …

Regulation Of Energy Stores And Feeding By Neuronal And Peripheral Creb Activity In Drosophila., Koichi Iijima, Lijuan Zhao, Christopher Shenton, Kanae Iijima-Ando

Department of Biochemistry and Molecular Biology Faculty Papers

The cAMP-responsive transcription factor CREB functions in adipose tissue and liver to regulate glycogen and lipid metabolism in mammals. While Drosophila has a homolog of mammalian CREB, dCREB2, its role in energy metabolism is not fully understood. Using tissue-specific expression of a dominant-negative form of CREB (DN-CREB), we have examined the effect of blocking CREB activity in neurons and in the fat body, the primary energy storage depot with functions of adipose tissue and the liver in flies, on energy balance, stress resistance and feeding behavior. We found that disruption of CREB function in neurons reduced glycogen and lipid stores …

Discovery And Validation Of New Regulatory Rna Elements In Chlamydia Trachomatis, Yasser Mohammed Elsayed Metwally Abdelrahman

Theses and Dissertations (ETD)

Chlamydia trachomatis is an obligate intracellular bacterium that exhibits a unique biphasic developmental cycle that can be disrupted by growth in the presence of IFN-g and b-lactams, giving rise to an abnormal growth state termed persistence. Relatively little is known about the regulatory mechanisms that control temporal gene expression during the developmental cycle or the control of persistence and reactivation. Here we have examined the expression of a newly defined family of non-coding RNAs (ncRNAs) that are differentially expressed during the developmental cycle and the induction of persistence and reactivation (Using IFNγ and Carbenicillin). Non-coding RNAs were initially identified using …

Suppression Of Erbb-2 In Androgen-Independent Human Prostate Cancer Cells Enhances Cytotoxic Effect By Gemcitabine In An Androgen-Reduced Environment., Li Zhang, Jeffrey S. Davis, Stanislav Zelivianski, Fen-Fen Lin, Rachel Schutte, Thomas L. Davis, Ralph Hauke, Surinder K. Batra, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

We examined the efficacy of combination treatments utilizing cytotoxic drugs plus inhibitors to members of the ErbB-ERK signal pathway in human prostate cancer (PCa) LNCaP C-81 cells. Under an androgen-reduced condition, 50nM gemcitabine caused about 40% growth suppression on C-81 cells. Simultaneous treatment of gemcitabine plus 10microM AG825 produced 60% suppression (p

Mcl-1 Degradation During Hepatocyte Lipoapoptosis., Howard C. Masuoka, Justin L. Mott, Steven F. Bronk, Nathan W. Werneburg, Yuko Akazawa, Scott H. Kaufmann, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

The mechanisms of free fatty acid-induced lipoapoptosis are incompletely understood. Here we demonstrate that Mcl-1, an anti-apoptotic member of the Bcl-2 family, was rapidly degraded in hepatocytes in response to palmitate and stearate by a proteasome-dependent pathway. Overexpression of a ubiquitin-resistant Mcl-1 mutant in Huh-7 cells attenuated palmitate-mediated Mcl-1 loss and lipoapoptosis; conversely, short hairpin RNA-targeted knockdown of Mcl-1 sensitized these cells to lipoapoptosis. Palmitate-induced Mcl-1 degradation was attenuated by the novel protein kinase C (PKC) inhibitor rottlerin. Of the two human novel PKC isozymes, PKCdelta and PKC, only activation of PKC was observed by phospho-immunoblot analysis. As compared with …

Pancreatic Cancer Cells Resistance To Gemcitabine: The Role Of Muc4 Mucin., S. Bafna, Sukhwinder Kaur, N. Momi, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: A major obstacle to the successful management of pancreatic cancer is to acquire resistance to the existing chemotherapeutic agents. Resistance to gemcitabine, the standard first-line chemotherapeutic agent for advanced and metastatic pancreatic cancer, is mainly attributed to an altered apoptotic threshold in the pancreatic cancer. The MUC4 transmembrane glycoprotein is aberrantly overexpressed in the pancreatic cancer and recently, has been shown to increase pancreatic tumour cell growth by the inhibition of apoptosis.

METHODS: Effect of MUC4 on pancreatic cancer cells resistance to gemcitabine was studied in MUC4-expressing and MUC4-knocked down pancreatic cancer cell lines after treatment with gemcitabine by …