Medicine and Health Sciences Commons^™

Mir-17* Suppresses Tumorigenicity Of Prostate Cancer By Inhibiting Mitochondrial Antioxidant Enzymes, Yong Xu, Fang Fang, Jiayou Zhang, Sajni Josson, William H. St. Clair, Daret K. St. Clair

Toxicology and Cancer Biology Faculty Publications

Aberrant micro RNA (miRNA) expression has been implicated in the pathogenesis of cancer. Recent studies have shown that the miR-17-92 cluster is overexpressed in many types of cancer. The oncogenic function of mature miRNAs encoded by the miR-17-92 cluster has been identified from the 5' arm of six precursors. However, the function of the miRNAs produced from the 3' arm of these precursors remains unknown. The present study demonstrates that miR-17* is able to suppress critical primary mitochondrial antioxidant enzymes, such as manganese superoxide dismutase (MnSOD), glutathione peroxidase-2 (GPX2) and thioredoxin reductase-2 (TrxR2). Transfection of miR-17* into prostate cancer PC-3 …

Dysregulation Of The Mitogen Granulin In Human Cancer Through The Mir-15/107 Microrna Gene Group, Wang-Xia Wang, Natasha Kyprianou, Xiaowei Wang, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

Granulin (GRN) is a potent mitogen and growth factor implicated in many human cancers, but its regulation is poorly understood. Recent findings indicate that GRN is regulated strongly by the microRNA miR-107, which functionally overlaps with miR-15, miR-16, and miR-195 due to a common 5′ sequence critical for target specificity. In this study, we queried whether miR-107 and paralogs regulated GRN in human cancers. In cultured cells, anti-argonaute RNA coimmunoprecipitation with downstream microarray analyses indicates that GRN mRNA is directly targeted by numerous miR-15/107 miRNAs. We further tested this association in human tumors. MiR-15 and miR-16 are known to be …

The Mir-15/107 Group Of Microrna Genes: Evolutionary Biology, Cellular Functions, And Roles In Human Diseases, John R. Finnerty, Wang-Xia Wang, Sébastien S. Hébert, Bernard R. Wilfred, Guogen Mao, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

The miR-15/107 group of microRNA (miRNA) gene is increasingly appreciated to serve key functions in humans. These miRNAs regulate gene expression involved in cell division, metabolism, stress response, and angiogenesis in vertebrate species. The miR-15/107 group has also been implicated in human cancers, cardiovascular disease and neurodegenerative disease, including Alzheimer's disease. Here we provide an overview of the following: (1) the evolution of miR-15/107 group member genes; (2) the expression levels of miRNAs in mammalian tissues; (3) evidence for overlapping gene-regulatory functions by different miRNAs; (4) the normal biochemical pathways regulated by miR-15/107 group miRNAs; and (5) the roles played …

Hepatitis C Virus Core-Derived Peptides Inhibit Genotype 1b Viral Genome Replication Via Interaction With Ddx3x, Chaomin Sun, Cara T. Pager, Guangxiang Luo, Peter Sarnow, Jamie H. D. Cate

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The protein DDX3X is a DEAD-box RNA helicase that is essential for the hepatitis C virus (HCV) life cycle. The HCV core protein has been shown to bind to DDX3X both in vitro and in vivo. However, the specific interactions between these two proteins and the functional importance of these interactions for the HCV viral life cycle remain unclear. We show that amino acids 16-36 near the N-terminus of the HCV core protein interact specifically with DDX3X both in vitro and in vivo. Replication of HCV replicon NNeo/C-5B RNA (genotype 1b) is significantly suppressed in HuH-7-derived cells expressing green fluorescent …

Cross-Reactivity Of Antibodies Against Leptospiral Recurrent Uveitis-Associated Proteins A And B (Lrua And Lrub) With Eye Proteins, Ashutosh Verma, Pawan Kumar, Kelly Babb, John F. Timoney, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Infection by Leptospira interrogans has been causally associated with human and equine uveitis. Studies in our laboratories have demonstrated that leptospiral lipoprotein LruA and LruB are expressed in the eyes of uveitic horses, and that antibodies directed against LruA and LruB react with equine lenticular and retinal extracts, respectively. These reactivities were investigated further by performing immunofluorescent assays on lenticular and retinal tissue sections. Incubation of lens tissue sections with LruA-antiserum and retinal sections with LruB-antiserum resulted in positive fluorescence. By employing two-dimensional gel analyses followed by immunoblotting and mass spectrometry, lens proteins cross-reacting with LruA antiserum were identified to …

White Matter Diffusion Alterations In Normal Women At Risk Of Alzheimer's Disease, Charles D. Smith, Himachandra Chebrolu, Anders H. Andersen, David A. Powell, Mark A. Lovell, Shuling Xiong, Brian T. Gold

Neurology Faculty Publications

Increased white matter mean diffusivity and decreased fractional anisotropy (FA) has been observed in subjects diagnosed with mild cognitive impairment (MCI) and Alzheimer's disease (AD). We sought to determine whether similar alterations of white matter occur in normal individuals at risk of AD. Diffusion tensor images were acquired in 42 cognitively normal right-handed women with both a family history of dementia and at least one apolipoprotein E4 allele. These were compared with images from 23 normal women without either AD risk factor. Group analyses were performed using tract-based spatial statistics. Reduced FA was observed in the fronto-occipital and inferior temporal …

High-Throughput Experimental Studies To Identify Mirna Targets Directly, With Special Focus On The Mammalian Brain, Peter T. Nelson, Marianthi Kiriakidou, Zissimos Mourelatos, Grace S. Tan, Mary H. Jennings, Kevin Xie, Wang-Xia Wang

Pathology and Laboratory Medicine Faculty Publications

We review the pertinent literature on methods used in high-throughput experimental identification of microRNA (miRNA) "targets" with emphasis on neurochemical studies. miRNAs are short regulatory noncoding RNAs that play important roles in the mammalian brain. The functions of miRNAs are related to their binding of RNAs including mRNAs. Since mammalian miRNAs tend to bind to target mRNAs via imperfect complementarity, understanding exactly which target mRNAs are recognized by which specific miRNAs is a challenge. Based on early experimental evidence, a set of "binding rules" for miRNAs has been described. These have focused on the 5' "seed" region of miRNAs binding …

Individual Micrornas (Mirnas) Display Distinct Mrna Targeting "Rules", Wang-Xia Wang, Bernard R. Wilfred, Kevin Xie, Mary H. Jennings, Yanling Hu, Arnold J. Stromberg, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

MicroRNAs (miRNAs) guide Argonaute (AGO)-containing microribonucleoprotein (miRNP) complexes to target mRNAs.It has been assumed that miRNAs behave similarly to each other with regard to mRNA target recognition. The usual assumptions, which are based on prior studies, are that miRNAs target preferentially sequences in the 3'UTR of mRNAs,guided by the 5' "seed" portion of the miRNAs. Here we isolated AGO- and miRNA-containing miRNPs from human H4 tumor cells by co-immunoprecipitation (co-IP) with anti-AGO antibody. Cells were transfected with miR-107, miR-124,miR-128, miR-320, or a negative control miRNA. Co-IPed RNAs were subjected to downstream high-density Affymetrix Human Gene 1.0 ST microarray analyses using …

Acetylation Of Wrn Protein Regulates Its Stability By Inhibiting Ubiquitination, Kai Li, Rui Wang, Enerlyn Lozada, Wei Fan, David K. Orren, Jianyuan Luo

Toxicology and Cancer Biology Faculty Publications

BACKGROUND: WRN is a multi-functional protein involving DNA replication, recombination and repair. WRN acetylation has been demonstrated playing an important role in response to DNA damage. We previously found that WRN acetylation can regulate its enzymatic activities and nuclear distribution.

METHODOLOGY/PRINCIPAL FINDING: Here, we investigated the factors involved in WRN acetylation and found that CBP and p300 are the only major acetyltransferases for WRN acetylation. We further identified 6 lysine residues in WRN that are subject to acetylation. Interestingly, WRN acetylation can increase its protein stability. SIRT1-mediated deacetylation of WRN reverses this effect. CBP dramatically increases the half-life of wild …

Anti-Argonaute Rip-Chip Shows That Mirna Transfections Alter Global Patterns Of Mrna Recruitment To Microribonucleoprotein Complexes, Wang-Xia Wang, Bernard R. Wilfred, Yanling Hu, Arnold J. Stromberg, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

MicroRNAs (miRNAs) play key roles in gene expression regulation by guiding Argonaute (AGO)-containing microribonucleoprotein (miRNP) effector complexes to target polynucleotides. There are still uncertainties about how miRNAs interact with mRNAs. Here we employed a biochemical approach to isolate AGO-containing miRNPs from human H4 tumor cells by co-immunoprecipitation (co-IP) with a previously described anti-AGO antibody. Co-immunoprecipitated (co-IPed) RNAs were subjected to downstream Affymetrix Human Gene 1.0 ST microarray analysis. During rigorous validation, the "RIP-Chip" assay identified target mRNAs specifically associated with AGO complexes. RIP-Chip was performed after transfecting brain-enriched miRNAs (miR-107, miR-124, miR-128, and miR-320) and nonphysiologic control miRNA to identify …

Mir-107 Is Reduced In Alzheimer's Disease Brain Neocortex: Validation Study, Peter T. Nelson, Wang-Xia Wang

Pathology and Laboratory Medicine Faculty Publications

MiR-107 is a microRNA (miRNA) that we reported previously to have decreased expression in the temporal cortical gray matter early in the progression of Alzheimer's disease (AD). Here we study a new group of well-characterized human temporal cortex samples (N=19). MiR-107 expression was assessed, normalized to miR-124 and let-7a. Correlation was observed between decreased miR-107 expression and increased neuritic plaque counts (P< 0.05) and neurofibrillary tangle counts (P< 0.02) in adjacent brain tissue. Adjusted miR-107 and BACE1 mRNA levels tended to correlate negatively (trend with regression P< 0.07). In sum, miR-107 expression tends to be lower relative to other miRNAs as AD progresses.