Antisense Oligonucleotides to Glucosylceramide Synthase Can Reverse Multidrug Resistance in Breast Cancer
Abstract
Glucosylceramide synthase (GCS) catalyzes ceramide glycosylation, disrupts ceramide- induced apoptosis elicited by chemotherapy, and appeared to be a major cause of multidrug resistance (MDR) in cancer. Previous studies pinpoint GCS as a therapeutic target for MDR. In this work, we have synthesized antisense GCS oligodeoxyribonucleotides (asGCS cDNs) to block GCS mRNA transcription, and tested several of the oligos for chemotherapy- enhancing properties in drug resistant cancer cell models. Antisense GCS ODN-7 suppressed OCS mRNA expression (RT-PCR) by 80%, and GCS protein (Western blot) by 40%, and affected 30-fold increases in sensitivity to Adriamycin in drug resistant breast cancer MCF-7-AdrR (EC50 0.25 vs. 7.8 %). Further, asGCS ODN-7 increased MCF-7-AdrR cell sensitivity to Taxol, Vinblastine, and Actinomycin D by 3-, 9- and 11-fold, respectively. Compared to asGCS ODN-7, the GCS chemical inhibitor, PDMP (D-threo-l-phenyl-2-decanoylamino-3- morpholino-l-propanol), was less efficient and increased Adriamycin sensitivity approximately 4-fold. Subsequent studies revealed that asGCS ODN-7 overcomes drug resistance by enhancing ceramide-induced apoptosis and drug uptake. In conclusion, antisense CCs oligonucleotides effectively depress GCS expression, enhance apoptosis and drug uptake, and increase chemotherapy sensitivity, making them promising agents for cancer therapy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2002
- Accession Number
- ADA407440
Entities
People
- Yong-yu Liu