Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that the E5a gene of human papilloma virus type 11 (HPV-11/HPV-6c) is a transforming oncogene. In order to dissect the biological consequences of E5a gene expression we utilized the lac operator/repressor system to manipulate E5a gene expression. Cells were cotransfected with the lac repressor gene and the E5a gene that had been inserted downstream of a simian virus 40 (SV40) promoter containing the lac operator sequence. The expression of E5a gene could therefore be repressed by binding of lac repressor to the lac operator sequence in proximity to this SV40 regulatory region. The transfected cells were cultured in the presence of the inducer IPTG and under G418 selection. IPTG derepressed E5a gene expression by binding to the repressor and reducing its affinity for the lac operator sequence. In these studies, we found that E5a-transformed cells still maintained the transformed phenotype as judged by growth density, cell morphology and anchorage-independent growth when E5a gene expression was repressed. We also found that c-jun expression was induced 3 h after E5a expression was induced by IPTG and c-jun expression was not shut down after repression of E5a expression. This is the first demonstration that the E5a gene of HPV-11 initiates transformation of NIH 3T3 cells but is dispensable for maintenance of the transformed phenotype.
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PMID:E5a gene of human papillomavirus type 11 is required for initiation but not for maintenance of transformation in NIH 3T3 cells. 804 97

The HPV16 (human papilloma virus type 16) E7 gene product, an oncoprotein, has been considered to be involved in the pathogenesis of anogenital cancer, particularly of cervical cancer. In order to evaluate the effect of suppression of the expression of the E7 gene in CV-1 cells by ribozyme, Rz523 with a transacting ribozyme targeted to the E7 RNA and two processing ribozyme genes at the 5' and 3' flank was cloned into the eukaryotic expression plasmid pREP9 under the control of RSV-LTR promoter. The resultant plasmid pRSV-Rz523 was transfected into CV-1 cells by calcium phosphate coprecipitation. The expression of the ribozyme in G418-resistant cells was detected by dot-blot hybridization. Ribozymes stably expressed in the CV-1 cells were at a level of 9.0 pmol per 10(6) cells, in which the active ribozyme molecules were more than 50 fmol per 10(6) cells. The result of RNase protection assay showed that the steady-state level of the E7 RNA fragment in CV-1 cell lines was significantly reduced by about 90% in ribozyme-expressing cells. In contrast, the antisense control plasmid pRSV-AE7 only exhibited about 20%. This result implicated the possibility of reversing the malignant phenotype of cervical cancer by means of suppressing the expression of the E7 gene with ribozyme.
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PMID:Stable expression of anti-HPV 16 E7-ribozyme in CV-1 cell lines. 918 92

HaCaT cells, a spontaneously immortalised, nontumorigenic keratinocyte line, were used as a more amenable model than primary keratinocytes for ex vivo-mediated gene transfer. These cells were transduced with retroviral vectors containing the factor IX cDNA under the control of a cytomegaloviral (CMV) promoter/enhancer alone or as hybrids with either the human papilloma virus-16 (HPV-16), keratin 14 (hK14) or keratin 5 (hK5) regulatory elements. Unlike primary keratinocytes, HaCaT cells tolerated transduction and G418 selection well. The HPV-16 and hK5 hybrid constructs were disproportionately more active in primary keratinocytes than in the basal-like HaCaT cells. After skin grafting to athymic mice, transduced HaCaT cells differentiated to form a stratified epidermis that remained viable for at least 99 days in some mice. Factor IX in plasma of mice grafted with vectors containing the HPV-16 and hK5 elements was two- to three-fold higher than with vectors containing the CMV promoter alone. These results are consistent with the expected up-regulation in differentiated suprabasal cells by the HPV-16 and hK5 elements. Enhancers may be useful in specifically targeting the differentiated layer of the epidermis or achieving higher levels of gene expression after transplantation.
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PMID:Differentiation-specific enhancer activity in transduced keratinocytes: a model for epidermal gene therapy. 961 60