Chemosensitization of gemcitabine-resistant human bladder cancer cell line both in vitro and in vivo using antisense oligonucleotide targeting the anti-apoptotic gene, clusterin.

Abstract

OBJECTIVE:

To characterize changes in clusterin (sCLU-2) expression in bladder cancer cells after continuous treatment with gemcitabine and to determine whether knockdown of sCLU-2 can re-introduce sensitivity of gemcitabine-resistant cells to treatment with gemcitabine.

MATERIALS AND METHODS:

A human bladder cancer cell line, UM-UC-3, was continuously exposed to increasing doses of gemcitabine in vitro, and a gemcitabine-resistant cell line UM-UC-3R was developed. The role of sCLU-2 in chemoresistant phenotype acquired in both in vitro and in vivo was then analysed using antisense oligonucleotide targeting the sCLU-2 gene (OGX-011).

RESULTS:

Treatment of parental UM-UC-3 cells (UM-UC-3P) with gemcitabine induced transient up-regulation of sCLU-2 protein. There was a sustained increase in sCLU-2 expression levels in UM-UC-3R compared with UM-UC-3P cells (6.4-fold). Treatment of UM-UC-3R cells with OGX-011 resulted in a dose-dependent and sequence- specific inhibition in sCLU-2 expression. Furthermore, OGX-011 chemo-sensitized UM-UC-3R cells to gemcitabine in vitro with a reduction in the concentration that reduces the effect by 50% (IC50) from 100 nm to 10 nm. Tumour volume and the incidence of metastasis in nude mice injected with UM-UC-3R cells was significantly greater than those of nude mice injected with UM-UC-3P cells; however, systemic administration of OGX-011 plus a low dose of gemcitabine significantly suppressed tumour volume and the incidence of metastasis in both groups.

CONCLUSION:

These findings suggest that sCLU-2 plays a significant role in the acquisition of chemoresistant phenotype in bladder cancer cells and the knockdown of sCLU-2 using OGX-011 combined with a chemotherapeutic agent could be an attractive approach for advanced bladder cancer through the enhancement of chemosensitivity.

• Authors: Mototsugu Muramaki, Alan So, Norihiro Hayashi, Richard Sowery, Hideaki Miyake, Masato Fujisawa, Martin E Gleave
• Journal: BJU international (BJU Int) Vol. 103 Issue 3 Pg. 384-90 (Feb 2009) ISSN: 1464-410X [Electronic] England
• PMID: 19007378 (Publication Type: Journal Article)

Chemical References

• Clusterin
• OGX-011
• Oligonucleotides, Antisense
• Thionucleotides
• Deoxycytidine
• Gemcitabine

Topics

• Animals
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Blotting, Western
• Cell Line, Tumor
• Clusterin (genetics, metabolism)
• Deoxycytidine (administration & dosage, analogs & derivatives)
• Dose-Response Relationship, Drug
• Drug Resistance, Neoplasm (drug effects, genetics)
• Humans
• In Vitro Techniques
• Mice
• Mice, Nude
• Neoplasm Metastasis
• Oligonucleotides, Antisense
• Thionucleotides (administration & dosage)
• Urinary Bladder Neoplasms (drug therapy, genetics)
• Gemcitabine