Androgen dependent regulation of protein kinase A subunits in prostate cancer cells.
Neuroendocrine (NE) cells may play a role in prostate cancer progression. Both androgen deprivation and cAMP are well known inducers of NE differentiation (NED) in the prostate. Gene-expression profiling of LNCaP cells, incubated in androgen stripped medium, showed that the Cbeta isoform of PKA is up-regulated during NE differentiation. Furthermore, by using semi-quantitative RT-PCR and immunoblotting analysis, we observed that the Cbeta splice variants are differentially regulated during this process. Whereas the Cbeta2 splice variant is down-regulated in growth arrested LNCaP cells, the Cbeta1, Cbeta3 and Cbeta4 variants, as well as the RIIbeta subunit of PKA, are induced in NE-like LNCaP cells. The opposite effect of Cbeta expression could be mimicked by androgen stimulation, implying the Cbeta gene of PKA as a putative new target gene for the androgen receptor in prostate cancer. Moreover, to investigate expression of PKA subunits during prostate cancer progression, we did immunoblotting of several prostatic cell lines and normal and tumor tissue from prostate cancer patients. Interestingly, multiple Cbeta subunits were also observed in human prostate specimens, and the Cbeta2 variant was up-regulated in tumor cells. In conclusion, it seems that the Cbeta isoforms play different roles in proliferation and differentiation and could therefore be potential markers for prostate cancer progression.
Kvissel
Anne-Katrine
AK
Department of Nutrition, University of Oslo, N-0317 Oslo, Norway.
Ramberg
Håkon
H
Eide
Turid
T
Svindland
Aud
A
Skålhegg
Bjørn Steen
BS
Taskén
Kristin Austlid
KA
D000728:Androgens / Q000494:pharmacology*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry; D008297:Male; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020033:Protein Isoforms
D000728:Androgens; D007527:Isoenzymes; D020033:Protein Isoforms; D017868:Cyclic AMP-Dependent Protein Kinases