JunD mediates androgen-induced oxidative stress in androgen dependent LNCaP human prostate cancer cells

• Published in: The Prostate 2008-06, Vol.68 (9), p.924-934
• Main Authors: Mehraein-Ghomi, Farideh, Lee, Elyse, Church, Dawn R., Thompson, Todd A., Basu, Hirak S., Wilding, George
• Format: Article
• Language: English
• Subjects: AP-1 transcription factor; Biological and medical sciences; Blotting, Western; Cell Line, Tumor; Genetic Vectors; Gynecology. Andrology. Obstetrics; Hormone Antagonists - pharmacology; Humans; JunD overexpression; JunD silencing; Male; Male genital diseases; Medical sciences; Metribolone - pharmacology; Neoplasms, Hormone-Dependent - genetics; Neoplasms, Hormone-Dependent - metabolism; Nephrology. Urinary tract diseases; Oxidative Stress - drug effects; Oxidative Stress - genetics; Prostatic Neoplasms - genetics; Prostatic Neoplasms - metabolism; Proto-Oncogene Proteins c-jun - biosynthesis; Proto-Oncogene Proteins c-jun - genetics; Proto-Oncogene Proteins c-jun - metabolism; reactive oxygen species; Reactive Oxygen Species - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Neoplasm - chemistry; RNA, Neoplasm - genetics; RNA, Small Interfering - genetics; Transcription Factor AP-1 - genetics; Transcription Factor AP-1 - metabolism; Transduction, Genetic; Transfection; Tumors; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/pros.20737

BACKGROUND Numerous and compelling evidence shows that high level of reactive oxygen species (ROS) plays a key role in prostate cancer occurrence, recurrence and progression. The molecular mechanism of ROS overproduction in the prostate gland, however, remains mostly unknown. Unique AP‐1 transcription factor JunD has been shown to inhibit cell proliferation, promote differentiation and mediate stress responses in a variety of eukaryotic cells. We previously reported that androgen–androgen receptor induced ROS production in androgen‐dependent LNCaP human prostate cancer cells is associated with increased JunD level/AP‐1 transcriptional activity. METHODS LNCaP cells constitutively overexpressing a functionally inactive form of JunD (JunDΔTA) or stably transfected with JunD siRNA (siJunD) to suppress JunD protein expression were established. Overexpression of JunD in LNCaP cells using transient transfection method was applied to assess the induction of ROS production in LNCaP cells. DCF assay was used to measure the ROS concentrations in the transfected as well as non‐transfected control cells. RT‐PCR and Western blot analyses were used to confirm silencing or overexpression of JunD in the transfected cells. RESULTS In the absence of androgen, LNCaP cells transiently transfected with a JunD overexpressing vector have relatively enhanced cellular ROS levels as compared to LNCaP cells transfected with a vector control. LNCaP cells that fail to express functional JunD (JunDΔTA or siJunD) do not exhibit any increase in ROS production in response to androgen. CONCLUSION Based on these data, we conclude that JunD is an essential mediator of the androgen‐induced increase in ROS levels in LNCaP cells. Prostate 68:924–934, 2008. © 2008 Wiley‐Liss, Inc.