Constitutive Activation of NF-kappaB in Prostate Carcinoma Cells Through a Positive Feedback Loop: Implication of Inducible IKK-Related Kinase (IKKi)
Abstract
The overall goal of this project is to understand the role of inducible IKK-related kinase IKKi in constitutive activation of anti-apoptotic transcription factor NF-kB prostate carcinoma (PC) cells. We found that IKKi is highly expressed in PC cell lines with constitutively activated NF-kB. We also performed immunostaining of more than 60 PC and BPH samples using four different antibodies against IKKi. Immunostaining revealed that IKKi was highly expressed in prostate glands, but not in prostate stroma. IKKi signal had both cytoplasm and nuclear localization. Overall intensity of IKKi staining was similar in BPH and in PCs, however, the nuclear expression was higher in PCs. Treatment of PC cells with different NF-kB inducers such as IL-1 alpha, TNF-alpha, and TPA resulted in a rapid induction of IKKi. Consistent with this, down-regulation of NF-kB activity by proteasome inhibitor MG 132 and IKK inhibitor PS1145 attenuated induction of IKKi expression by NF-kB inducers. Transient transfection of different PC cell lines with IKKi w.t. resulted in activation of kB.Luciferase reporter, whereas IKKi dominant negative mutant suppressed basal NF-kB activity in PC cells. These data provide experimental evidence that IKKi could be involved in the regulation of NF-kB activity in PC cells through a positive feedback loop.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2004
- Accession Number
- ADA435282
Entities
People
- Irina V. Budunova
Organizations
- Northwestern University