JunD mediates androgen-induced oxidative stress in androgen dependent LNCaP human prostate cancer cells.
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 (JunDDeltaTA) 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 (JunDDeltaTA or siJunD) do not exhibit any increase in ROS production in response to androgen.


CONCLUSIONS
Based on these data, we conclude that JunD is an essential mediator of the androgen-induced increase in ROS levels in LNCaP cells.
Mehraein-Ghomi
Farideh
F
University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin, Madison, USA.
Lee
Elyse
E
Church
Dawn R
DR
Thompson
Todd A
TA
Basu
Hirak S
HS
Wilding
George
G
D015153:Blotting, Western; D045744:Cell Line, Tumor; D005822:Genetic Vectors; D006727:Hormone Antagonists / Q000494:pharmacology; D006801:Humans; D008297:Male; D015741:Metribolone / Q000494:pharmacology; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism; D014161:Transduction, Genetic; D014162:Transfection
D006727:Hormone Antagonists; D016755:Proto-Oncogene Proteins c-jun; D012334:RNA, Neoplasm; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D018808:Transcription Factor AP-1; D015741:Metribolone