|
|
|
|
|
|
|
Free Newsletters
Archive
My Subscriptions

News by Subject
News by Disease
News by Date
PLoS
Search News
Post Your News
JoVE

Job Seeker Login
Most Recent Jobs
Browse Biotech Jobs
Search Jobs
Post Resume
Career Fairs
Career Resources
For Employers

Regional News
US & Canada
Biotech Bay
Biotech Beach
Genetown
Pharm Country
BioCapital
BioMidwest
Bio NC
BioForest
Southern Pharm
BioCanada East
US Device
Europe
Asia


Market Summary
News
IPOs

Company Profiles

Companies
Events

Research Store

Biotech Events
Post an Event

Real Estate
Business Opportunities
|
|
|
|
|
PLoS By Category | Recent
PLoS Articles
|
|
Biochemistry - Molecular Biology - Oncology - Pharmacology - Urology - Virology
|
Adenovirus-Mediated Sensitization to the Cytotoxic Drugs Docetaxel and Mitoxantrone Is Dependent on Regulatory Domains in the E1ACR1 Gene-Region
Published:
Wednesday, October 03, 2012
Author:
Enrique Miranda et al.
by Enrique Miranda, Hector Maya Pineda, Daniel Öberg, Gioia Cherubini, Zita Garate, Nick R. Lemoine, Gunnel Halldén
Oncolytic adenoviruses have shown promising efficacy in clinical trials targeting prostate cancers that frequently develop resistance to all current therapies. The replication-selective mutants Ad?? and dl922–947, defective in pRb-binding, have been demonstrated to synergise with the current standard of care, mitoxantrone and docetaxel, in prostate cancer models. While expression of the early viral E1A gene is essential for the enhanced cell killing, the specific E1A-regions required for the effects are unknown. Here, we demonstrate that replicating mutants deleted in small E1A-domains, binding pRb (dl1108), p300/CBP (dl1104) and p400/TRRAP or p21 (dl1102) sensitize human prostate cancer cells (PC-3, DU145, 22Rv1) to mitoxantrone and docetaxel. Through generation of non-replicating mutants, we demonstrate that the small E1A12S protein is sufficient to potently sensitize all prostate cancer cells to the drugs even in the absence of viral replication and the E1A transactivating domain, conserved region (CR) 3. Furthermore, the p300/CBP-binding domain in E1ACR1 is essential for drug-sensitisation in the absence (AdE1A1104) but not in the presence of the E1ACR3 (dl1104) domain. AdE1A1104 also failed to increase apoptosis and accumulation of cells in G2/M. All E1A?CR2 mutants (AdE1A1108, dl922–947) and AdE1A1102 or dl1102 enhance cell killing to the same degree as wild type virus. In PC-3 xenografts in vivo the dl1102 mutant significantly prolongs time to tumor progression that is further enhanced in combination with docetaxel. Neither dl1102 nor dl1104 replicates in normal human epithelial cells (NHBE). These findings suggest that additional E1A-deletions might be included when developing more potent replication-selective oncolytic viruses, such as the Ad?CR2-mutants, to further enhance potency through synergistic cell killing in combination with current chemotherapeutics.
More...
|
|
|
 |
 |
|
|
|
|
|
|
|
|