Paxillin mediates extranuclear and intranuclear signaling in prostate cancer proliferation.
In prostate cancer, the signals that drive cell proliferation change as tumors progress from castration-sensitive (androgen-dominant) to castration-resistant states. While the mechanisms underlying this change remain uncertain, characterization of common signaling components that regulate both stages of prostate cancer proliferation is important for developing effective treatment strategies. Here, we demonstrate that paxillin, a known cytoplasmic adaptor protein, regulates both androgen- and EGF-induced nuclear signaling. We show that androgen and EGF promoted MAPK-dependent phosphorylation of paxillin, resulting in nuclear translocation of paxillin. We found nuclear paxillin could then associate with androgen-stimulated androgen receptor (AR). This complex bound AR-sensitive promoters, retaining AR within the nucleus and regulating AR-mediated transcription. Nuclear paxillin also complexed with ERK and ELK1, mediating c-FOS and cyclin D1 expression; this was followed by proliferation. Thus, paxillin is a liaison between extranuclear MAPK signaling and nuclear transcription in response to androgens and growth factors, making it a potential regulator of both castration-sensitive and castration-resistant prostate cancer. Accordingly, paxillin was required for normal growth of human prostate cancer cell xenografts, and its expression was elevated in human prostate cancer tissue microarrays. Paxillin is therefore a potential biomarker for prostate cancer proliferation and a possible therapeutic target for prostate cancer treatment.
Division of Endocrinology and Metabolism, University of Rochester Medical Center, Rochester, NY, USA.
Aritro
A
Sen
Ismary
I
De Castro
Donald B
DB
Defranco
Fang-Ming
FM
Deng
Jonathan
J
Melamed
Payel
P
Kapur
Ganesh V
GV
Raj
Randall
R
Rossi
Stephen R
SR
Hammes
D021581:Active Transport, Cell Nucleus; D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D049109:Cell Proliferation; D013196:Dihydrotestosterone / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006107:Granulosa Cells / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D020935:MAP Kinase Signaling System; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D051419:Paxillin / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017430:Prostate-Specific Antigen / Q000235:genetics / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011485:Protein Binding; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D011944:Receptors, Androgen / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D050807:ets-Domain Protein Elk-1 / Q000378:metabolism
C494112:ELK1 protein, human; D018398:Homeodomain Proteins; C491178:NKX3-1 protein, human; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D016760:Proto-Oncogene Proteins c-fos; D011944:Receptors, Androgen; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; D013196:Dihydrotestosterone; D048049:Extracellular Signal-Regulated MAP Kinases; D017430:Prostate-Specific Antigen