Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We evaluated the interaction between oncolytic, replication-competent adenoviral vectors and the herpes simplex virus-1 thymidine kinase (HSV1-tk) gene/ganciclovir (GCV) suicide system for the treatment of malignant gliomas. We constructed a panel of replication-competent adenoviral vectors in which the luciferase (IG.Ad5E1(+). E3Luc) or HSV1-tk gene (IG.Ad5E1(+).E3TK) replace the M(r) 19,000 glycoprotein (gp19K) coding sequence in the E3 region. IG.Ad5E1. IG.Ad5.ClipLuc and IG.AdApt.TK are E1-deleted viruses that contain the luciferase or the HSV1-tk gene in the former E1 region driven by the human cytomegalovirus promoter. IG.Ad5. Sarcoma 1800HSA.E3Luc contains an irrelevant gene in the E1 region, whereas the gp19K coding sequence in the E3 region is replaced by the luciferase gene as in the replicating virus IG.Ad5E1(+).E3Luc. For in vitro experiments, we used a panel of human glioma cell lines (U87 MG, T98G, A172, LW5, and U251), a rat gliosarcoma cell line (9 L), and human lung (A549) and prostate carcinoma (P3) cell lines. In vitro, GCV sensitivity (10 microg/ml) was studied in U87 MG cells after infection at a multiplicity of infection of 1 and 10. A s.c. U87 MG glioma xenograft model was established in NIH-bg-nu-xid mice. Tumors of 100-150 mm(3) were treated with a single injection of adenovirus 10(9) IU suspended in 100 microl of PBS, and GCV 100 mg/kg was administered i.p. twice daily for 7 days. The cytopathic effect of all three replication-competent adenoviral vectors was similar to the cytopathic effect of wild-type adenovirus 5 on all human cell lines tested, indicating that deletion of the E3 gp19K sequences did not affect the oncolytic effect of the vectors. In vitro, luciferase expression was the same for both E1-deleted vectors (IG.Ad5.ClipLuc and IG.Ad5. Sarcoma 1800HSA.E3Luc), demonstrating the strength of the internal E3 promoter even in the absence of E1A. However, in vitro expression levels obtained with replication-competent IG.Ad5E1(+). E3Luc were 3 log higher (allowing infection with a 2-3-log lower multiplicity of infection) in the human cell lines. In U87 MG glioma cells, the oncolytic effect of replication-competent IG.Ad5E1(+).E3TK was significantly enhanced by the addition of GCV and greatly exceeded the cytotoxicity of replication-incompetent IG.AdApt.TK combined with GCV. In established s.c. U87 MG glioma xenografts, a single injection of IG.Ad5E1(+).E3TK resulted in a significant slowing of tumor growth and prolonged survival compared with injection of IG.AdApt.TK. Addition of GCV slowed tumor growth, further adding to survival. In conclusion, the oncolytic effect of replicating adenoviral vectors and HSV1-tk/GCV have potent antitumor effects in gliomas. When combined, these two approaches are complementary, resulting in a significantly improved treatment outcome. In addition, replication-competent adenoviral vectors missing the E3 gp19K coding sequences, have oncolytic efficacy comparable with wild type. In combination with high expression levels obtained with the natural E3 promoter, such vectors are promising new anticancer agents.
 ...
PMID:Treatment of malignant gliomas with a replicating adenoviral vector expressing herpes simplex virus-thymidine kinase. 1175 94

The main purpose of this study was to develop self-emulsifying drug delivery systems (SEDDS) for the improvement of the stability of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) after released from poly (D,L-lactide-co-glycolide) (PLGA) wafer and to evaluate its in vitro antitumor activity against 9L gliosarcoma cells. The in vitro stability test of BCNU was characterized by the BCNU amount in phosphate buffered saline (PBS, pH 7.4) at 37 degrees C. SEDDS increased in vitro half-life of BCNU up to 130 min compared to 45 min of intact BCNU. Self-emulsified (SE) BCNU was fabricated into wafers with flat and smooth surface by compression molding. In vitro release of BCNU from SE BCNU-loaded PLGA wafer was prolonged up to 7 days followed first order release kinetics. Beside, the cytotoxicity of SE BCNU-loaded PLGA wafer against 9L gliosarcoma cells was higher than intact BCNU-loaded PLGA wafer which is more susceptible to hydrolysis. SE BCNU degraded much more slowly than the intact BCNU in PLGA matrix at 25 degrees C. These results strongly suggest that the self-emulsion system increased the stability of BCNU after released from PLGA wafer. From these results, it could be expected that the penetration depth of BCNU could be improved in brain tissue using self-emulsion system.
 ...
PMID:Enhancement of the stability of BCNU using self-emulsifying drug delivery systems (SEDDS) and in vitro antitumor activity of self-emulsified BCNU-loaded PLGA wafer. 1602 90