text: Woolfenden, S.; Zhu, H.; Charest, A.
  A Cre/LoxP conditional luciferase reporter transgenic mouse for bioluminescence monitoring of tumorigenesis
  IVIS, Xenogen
  Genetically engineered, Cre/LoxP-conditional mouse models of cancer are designed to investigate the genetic contributors of tumorigenesis and are well suited to assess therapeutic treatment responses. The capacity to serially visualize tumor burden in a noninvasive fashion would greatly strengthen their applications. We report the generation of a bioluminescent reporter strain that allows monitoring of tumor development in preexisting conditional mouse tumor models. We demonstrate that, in a Cre-dependent glioblastoma multiforme model, tumor initiation and progression is readily monitored over time and that luminescent output is related to tumor volume. Our results show that this reporter strain may be combined with various Cre/loxP mouse tumor models to allow for noninvasive longitudinal monitoring of tumor growth and therapeutic response in vivo. genesis 00:1-8, 2009. (c) 2009 Wiley-Liss, Inc.
  http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19603508
  Dieguez-Hurtado, R.; Martin, J.; Martinez-Corral, I.; Martinez, M. D.; Megias, D.; Olmeda, D.; Ortega, S.
  A Cre-reporter transgenic mouse expressing the far-red fluorescent protein Katushka
  Animals, Flow Cytometry/methods, Genes, Reporter, Integrases/*genetics, Luminescent Proteins/*genetics, Mice, Mice, Transgenic, Microscopy, Confocal/methods, Promoter Regions, Genetic, Recombination, Genetic
  Cre/loxP-dependent expression of fluorescent proteins represents a powerful biological tool for cell lineage, fate-mapping, and genetic analysis. Live tissue imaging has significantly improved with the development of far-red fluorescent proteins, with optimized spectral characteristics for in vivo applications. Here, we report the generation of the first transgenic mouse line expressing the far-red fluorescent protein Katushka, driven by the hybrid CAG promoter upon Cre-mediated recombination. After germ line or tissue-specific Cre-driven reporter activation, Katushka expression is strong and ubiquitous, without toxic effects, allowing fluorescence detection in fresh and fixed samples from all tissues examined. Moreover, fluorescence can be detected by in vivo noninvasive whole-body imaging when Katuhska is expressed exclusively in a specific cell population deep within the animal body such as pancreatic beta cells. Thus, this reporter model enables early, widespread, and sensitive in vivo detection of Cre activity and should provide a versatile tool for a wide spectrum of fluorescence and live-imaging applications.
  http://www.ncbi.nlm.nih.gov/pubmed/21254335
  Huang, EH; Singh, B; Cristofanilli, M; Gelovani, J; Wei, C; Vincent, L; Cook, KR; Lucci, A
  A CXCR4 Antagonist CTCE-9908 Inhibits Primary Tumor Growth and Metastasis of Breast Cancer1
  BACKGROUND: CXCL12/CXCR4 signaling may be involved in tumor growth and angiogenesis, and homing of cancer cells to bone and other organs. Our purpose was to determine whether inhibition of CXCR4 with a peptide-based antagonist would reduce tumor growth and metastasis of breast cancer.x000Dx000DMETHODS: We used two mouse models of breast cancer. In the first model, 1 x 10(6) MDA-MB-231 breast cancer cells transfected with luciferase were implanted into the inguinal mammary fat pad to produce primary tumors. In the second model, 1 x 10(5) MDA-231-BSC12 cells were injected into the left cardiac ventricle to produce bone metastases. CTCE-9908, a peptide analog of CXCL12 that competitively binds to CXCR4, was used to test the effect of inhibiting CXCR4. Five mice from each mouse model were treated with CTCE-9908 (25 mg/kg, injected subcutaneously 5 d/wk). All mice were assessed weekly using bioluminescent imaging to quantify relative volumes of tumor burden.x000Dx000DRESULTS: Bioluminescencent imaging showed that the mice treated with CTCE-9908 had significantly less primary tumor burden than the control mice. At 5 and 6 wk, the mice treated with CTCE-9908 had a 7-fold reduction and 5-fold reduction in primary tumor burden, respectively. Treatment with CTCE-9908 also significantly inhibited the rate of metastases compared with the control group. At 5 and 6 wk, the mice treated with CTCE-9908 demonstrated a 9-fold reduction and 20-fold reduction in metastatic tumor burden, respectively.x000Dx000DCONCLUSION: Treatment with the CXCR4 antagonist CTCE-9908 significantly reduced metastasis as well as primary tumor growth in mouse models of breast cancer.
  Zhang, W.; Moorthy, B.; Chen, M.; Muthiah, K.; Coffee, R.; Purchio, A. F.; West, D. B.
  A Cyp1a2-luciferase transgenic CD-1 mouse model: responses to aryl hydrocarbons similar to the humanized AhR mice
  Amino Acid Sequence, Animals, Animals, Outbred Strains, Cytochrome P-450 CYP1A2/biosynthesis/ genetics, Female, Gene Expression Regulation/ drug effects, Genes, Reporter/genetics, Humans, Hydrocarbons, Aromatic/ toxicity, Luciferases/biosynthesis/ genetics, Male, Mice, Mice, Transgenic, Models, Animal, Molecular Sequence Data, Polymorphism, Genetic, RNA, Messenger/metabolism, Receptors, Aryl Hydrocarbon/metabolism IVIS, Xenogen
  Here we describe a transgenic mouse model [Crl:CD-1(ICR)BR-Tg(Cyp1a2-luc)Xen] using luciferase as a reporter for Cyp1a2 gene regulation. An 8.4-kilobase mouse Cyp1a2 promoter driving the firefly luciferase gene was microinjected into single-cell-stage CD-1 mouse embryos. A transgenic mouse line was selected based on basal and induced levels of the transgene in mouse liver by an in vivo bioluminescent imaging method. The basal levels of the luciferase reporter in liver were expressed much higher than other tissues, which correlated well with the endogenous Cyp1a2 mRNA tissue distribution. Male signals were about 23-fold higher than females in liver. However, the Cyp1a2 mRNA showed no gender difference. When mice were challenged with xenobiotics, the liver luciferase signal was induced to various degrees. At the doses we used, the relative effects were phenobarbital > 2,3,7,8-tetrachlorodibenzo-p-dioxin > 3-methylcholanthrene > benzo[a]pyrene and beta-naphthoflavone. Induction of the Cyp1a2-luc reporter was generally consistent with the endogenous Cyp1a2 mRNA. However, phenobarbital induction was unexpectedly higher, while beta-naphthoflavone induction of the reporter was much lower than that of the endogenous Cyp1a2 gene. Induction of the Cyp1a2-luc transgene by aryl hydrocarbons (Ah) in the CD-1 background was much less than that found in the Ah responsive C57BL/6 mice, while being similar to the nonresponsive DBA/2 strain. Sequence analysis of the CD-1 Ah receptor (AhR) cDNA clones demonstrated that consensus sequence was identical to some of the Ah-responsive strains such as BALB/C and CBA/J mice. The 104-kD AhR protein was not detectable in CD-1 mice, while the 97-kD AhR was detected in the C57BL/6 mice by Western blot using an AhR antibody. Low expression of the AhR in CD-1 mice could be in part responsible for low responsiveness to Ah compounds. The findings demonstrated the outbred CD-1 mouse is a low-responsive strain, and the Cyp1a2-luc transgenic CD-1 mice can be used for studying the regulation of the mouse Cyp1a2 gene in an Ah low-responsive strain in real time using the bioluminescent imaging approach.
  Somjen, D.; Katzburg, S.; Nevo, N.; Gayer, B.; Hodge, R. P.; Renevey, M. D.; Kalchenko, V.; Meshorer, A.; Stern, N.; Kohen, F.
  The use of daunomycin against neoplasms is limited due to its severe cardiotoxicity. The cytotoxicity of daunomycin can be minimized by linking it to an affinity tag. Since ovarian cancer cells are sensitive to isoflavone action, we synthesized a daidzein daunomycin conjugate. In MLS human ovarian cancer cells, the conjugate was shown to have a larger cytotoxic effect than daunomycin per se at a low concentration. The conjugate was then tested in vivo in mice carrying MLS xenografts. Tumour growth in the groups of conjugate and daunomycin was inhibited by >50% as compared to vehicle treated mice. In contrast to daunomycin treated mice, no weight reduction or death was seen in mice treated with the conjugate. In vivo imaging of the fluorescence signal generated by daunomycin indicated uptake of both conjugate and daunomycin by the tumour. Tumour fluorescence was, however, higher in the conjugate treated mice than in the daunomycin treated mice, thus suggesting specific delivery of the drug to the tumour. Histological examination of myocardial tissue indicated that only the daunomycin, but not conjugate treated mice showed cardiac damage. These results indicate that targeting of daunomycin via carboxymethyldaidzein retains daunomycin's cytotoxic effects while averting its toxicity in an ovarian xenograft.
  http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18482833
  Kadurugamuwa, J. L.; Sin, L.; Albert, E.; Winterberg, P.; Larkin, A.; Bellinger-Kawahara, C.; DeBoer, M.; Yu, J.; Rubin, M.; Francis, K.; Parr, T.
  ://BIOSIS:PREV200200597266">A direct continuous method to monitor biofilms on medical devices
  Abstracts of the General Meeting of the American Society for Microbiology
  Infection, Methods and Techniques, 00520, General biology – Symposia, transactions and proceedings, 12512, Pathology – Therapy, 25502, Development and Embryology -, General and descriptive, 31000, Physiology and biochemistry of, bacteria, 36001, Medical and clinical microbiology – General and, methods, 38504, Chemotherapy – Antibacterial agents, Gram-Positive Cocci, Eubacteria, Bacteria, Microorganisms, Bacteria,, Eubacteria, Microorganisms, Micrococcaceae [07702], [Staphylococcus, aureus, (pathogen)] [Staphylococcus epidermidis, (pathogen)]/Rodentia,, Mammalia, Vertebrata, Chordata, Animalia, Animals, Chordates, Mammals,, Nonhuman Vertebrates, Nonhuman Mammals, Rodents, Vertebrates, Muridae, [86375], [mouse, (host)]/Gram-Negative Aerobic Rods and Cocci,, Eubacteria, Bacteria, Microorganisms, Bacteria, Eubacteria,, Microorganisms, Pseudomonadaceae [06508], [Pseudomonas aeruginosa, (pathogen)], Teflon catheter, medical equipment/antibiotic therapy, therapeutic, method/bioluminescence, analytical method/medical devices biofilm, monitoring, analytical method/medical implants, medical, equipment/rapid, direct non destructive, real time quantitative, monitoring methods, development, monitoring method IVIS, Xenogen
  Background: Microbial adhesion and biofilm formation on medical implants is a common occurrence and represents a serious medical problem, as these bacteria are difficult to eradicate with antibiotic therapy and leads to chronic infections. Rapid, direct, non destructive, real time quantitative monitoring methods that are adaptable to the clinical situation are needed to develop new preventive and therapeutic methods to combat biofilm related infections. Method: We have developed a rapid, innocuous method for real time monitoring of biofilms in vitro and in a mouse infection model by establishing biofilms of bioluminescent bacteria on Teflon catheters. The capacity of the microbes to form biofilm on catheter material, their suitability for long-term experiments, and metabolic state of biofilms was assessed in situ by monitoring the bioluminescence with an IVIS imaging system (Xenogen Corp., Alameda, CA). Results: Three different biofilm forming bacterial pathogens, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, made bioluminescent by insertion of the lux operon, produced significant bioluminescent signals, both in vitro and in mice, allowing effective assessment of the physiological state of biofilm. Unlike plasmid-based lux constructs, chromosomal lux gene integrants were stable, and bioluminescence detectable for 21 days. Viable cell counts and light output were parallel, highly correlated (r=0.95) and could be maintained in vitro for 15 days or longer if growth medium is replenished every 24h. For the complete removal of bacteria from support surface to enumerate viable cells using conventional methods, vigorous votexing (5 min or more) was necessary. Aged biofilms (24 h) of P. aeruginosa were the most difficult to disassociate from the catheter followed by S. aureus. Conclusion: The ability to monitor biofilms in real time without exogenous sampling accelerates the study of biofilm population. Since the metabolic activity of viable cells could be detected directly on support matrix non destructively and non invasively, the methodology is especially appealing for in vivo and drug development studies.
  ://BIOSIS:PREV200200597266"">://BIOSIS:PREV200200597266
  Wang, Q; Dolyle, T; Cao, Y; Contag, CH
  A Dual bioluminescent reporter transgenic mouse strain for noninvasive bioluminescent imaging of cells that have undergone cre-mediated recombination-a useful model for development research
  Kimura, R. H.; Miao, Z.; Cheng, Z.; Gambhir, S. S.; Cochran, J. R.
  http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=20131753
  Wangensteen, K. J.; Wilber, A.; Keng, V. W.; He, Z.; Matise, I.; Wangensteen, L.; Carson, C. M.; Chen, Y.; Steer, C. J.; McIvor, R. S.; Largaespada, D. A.; Wang, X.; Ekker, S. C.
  A facile method for somatic, lifelong manipulation of multiple genes in the mouse liver
  Current techniques for the alteration of gene expression in the liver have a number of limitations, including the lack of stable somatic gene transfer and the technical challenges of germline transgenesis. Rapid and stable genetic engineering of the liver would allow systematic, in vivo testing of contributions by many genes to disease. After fumaryl acetoacetate hydrolase (Fah) gene transfer to hepatocytes, selective repopulation of the liver occurs in FAH-deficient mice. This genetic correction is readily mediated with transposons. Using this approach, we show that genes with biological utility can be linked to a selectable Fah transposon cassette. First, net conversion of Fah(-/-) liver tissue to transgenic tissue, and its outgrowth, was monitored by bioluminescence in vivo from a luciferase gene linked to the FAH gene. Second, coexpressed short hairpin RNAs (shRNAs) stably reduced target gene expression, indicating the potential for loss-of-function assays. Third, a mutant allele of human alpha1-antitrypsin (hAAT) was linked to Fah and resulted in protein inclusions within hepatocytes, which are the histopathological hallmark of hAAT deficiency disorder. Finally, oncogenes linked to Fah resulted in transformation of transduced hepatocytes. Conclusion: Coexpression with FAH is an effective technique for lifelong expression of transgenes in adult hepatocytes with applicability to a wide variety of genetic studies in the liver.
  http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18435462
  Liu, Y.; Dentin, R.; Chen, D.; Hedrick, S.; Ravnskjaer, K.; Schenk, S.; Milne, J.; Meyers, D. J.; Cole, P.; Yates, J.; Olefsky, J.; Guarente, L.; Montminy, M.
  A fasting inducible switch modulates gluconeogenesis via activator/coactivator exchange
  Acetylation, Animals, CREB-Binding Protein/metabolism, Cell Line, Transformed, Cyclic AMP Response Element-Binding Protein/metabolism, Enzyme Inhibitors/pharmacology, Fasting/*physiology, Forkhead Transcription Factors/metabolism, Gene Expression Regulation/drug effects, Gluconeogenesis/*physiology, Heterocyclic Compounds with 4 or More Rings/pharmacology, Humans, Liver/metabolism, Male, Mice, Mice, Knockout, Nuclear Proteins/metabolism, Sirtuins/genetics/metabolism, Stilbenes/pharmacology, Trans-Activators/metabolism, Ubiquitin-Protein Ligases/metabolism, p300-CBP Transcription Factors/metabolism IVIS, Xenogen
  During early fasting, increases in skeletal muscle proteolysis liberate free amino acids for hepatic gluconeogenesis in response to pancreatic glucagon. Hepatic glucose output diminishes during the late protein-sparing phase of fasting, when ketone body production by the liver supplies compensatory fuel for glucose-dependent tissues. Glucagon stimulates the gluconeogenic program by triggering the dephosphorylation and nuclear translocation of the CREB regulated transcription coactivator 2 (CRTC2; also known as TORC2), while parallel decreases in insulin signalling augment gluconeogenic gene expression through the dephosphorylation and nuclear shuttling of forkhead box O1 (FOXO1). Here we show that a fasting-inducible switch, consisting of the histone acetyltransferase p300 and the nutrient-sensing deacetylase sirtuin 1 (SIRT1), maintains energy balance in mice through the sequential induction of CRTC2 and FOXO1. After glucagon induction, CRTC2 stimulated gluconeogenic gene expression by an association with p300, which we show here is also activated by dephosphorylation at Ser 89 during fasting. In turn, p300 increased hepatic CRTC2 activity by acetylating it at Lys 628, a site that also targets CRTC2 for degradation after its ubiquitination by the E3 ligase constitutive photomorphogenic protein (COP1). Glucagon effects were attenuated during late fasting, when CRTC2 was downregulated owing to SIRT1-mediated deacetylation and when FOXO1 supported expression of the gluconeogenic program. Disrupting SIRT1 activity, by liver-specific knockout of the Sirt1 gene or by administration of a SIRT1 antagonist, increased CRTC2 activity and glucose output, whereas exposure to SIRT1 agonists reduced them. In view of the reciprocal activation of FOXO1 and its coactivator peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha, encoded by Ppargc1a) by SIRT1 activators, our results illustrate how the exchange of two gluconeogenic regulators during fasting maintains energy balance.
  http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18849969