Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2010-1-4
pubmed:abstractText
phi C31 integrase has emerged as a potent tool for achieving long-term gene expression in different tissues. The present study aimed at optimizing elements of phi C31 integrase system for alveolar type II cells. Luciferase and beta-galactosidase activities were measured at different time points post transfection. 5-Aza-2'deoxycytidine (AZA) and trichostatin A (TSA) were used to inhibit DNA methyltransferase and histone deacetylase complex (HDAC) respectively. In A549 cells, expression of the integrase using a CMV promoter resulted in highest integrase activity, whereas in MLE12 cells, both CAG and CMV promoter were equally effective. Effect of polyA site was observed only in A549 cells, where replacement of SV40 polyA by bovine growth hormone (BGH) polyA site resulted in an enhancement of integrase activity. Addition of a C-terminal SV40 nuclear localization signal (NLS) did not result in any significant increase in integrase activity. Long-term expression studies with AZA and TSA, provided evidence for post-integrative gene silencing. In MLE12 cells, both DNA methylases and HDACs played a significant role in silencing, whereas in A549 cells, it could be attributed majorly to HDAC activity. Donor plasmids comprising cellular promoters ubiquitin B (UBB), ubiquitin C (UCC) and elongation factor 1 alpha (EF1 alpha) in an improved backbone prevented post-integrative gene silencing. In contrast to A549 and MLE12 cells, no silencing could be observed in human bronchial epithelial cells, BEAS-2B. Donor plasmid coding for murine erythropoietin under the EF1 alpha promoter when combined with phi C31 integrase resulted in higher long-term erythropoietin expression and subsequently higher hematocrit levels in mice after intravenous delivery to the lungs. These results provide evidence for cell specific post integrative gene silencing with C31 integrase and demonstrate the pivotal role of donor plasmid in long-term expression attained with this system.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-10757023, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-11359900, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-11472109, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-11704814, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-12027557, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-12034816, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-12189244, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-12244305, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-12379870, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-12946323, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-15029228, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-15656784, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-15727936, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-16142827, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-16240995, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-16387861, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-16414067, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-17069535, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-17225864, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-17408235, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-17712864, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-17938204, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-18718925, http://linkedlifedata.com/resource/pubmed/commentcorrection/19745601-3548772
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1226-3613
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
919-34
pubmed:dateRevised
2010-9-28
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Optimization of Streptomyces bacteriophage phi C31 integrase system to prevent post integrative gene silencing in pulmonary type II cells.
pubmed:affiliation
Division of Molecular Pulmonology, Department of Pediatrics, Ludwig-Maximilians University, Lindwurmstrasse 2A, 80337 Munich, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't