TY - JOUR
T1 - Protein kinase A isozyme switching
T2 - Eliciting differential cAMP signaling and tumor reversion
AU - Neary, Catherine L.
AU - Nesterova, Maria
AU - Yee, Sook Cho
AU - Cheadle, Chris
AU - Becker, Kevin G.
AU - Cho-Chung, Yoon S.
PY - 2004/11/18
Y1 - 2004/11/18
N2 - The cAMP-dependent protein kinase types I (PKA-I) and II (PKA-II), composed of identical catalytic (C) subunits but distinct regulatory (R) subunits (RI versus RII), are expressed in a balance of cell growth and differentiation. Distortion of this balance may underlie tumorigenesis and tumor growth. Here, we used PC3M prostate carcinoma cells as a model to overexpress wild type and mutant R and C subunit genes and examined the effects of differential expression of these genes on tumor growth. Only the RIIβ and mutant RIα-P (a functional mimic of RIIβ) transfectants exhibited growth inhibition in vitro, reverted phenotype, and apoptosis, and inhibited in vivo tumor growth. DNA microarrays demonstrated that RIIβ and RIα-P overexpression upregulated a cluster of differentiation genes, while downregulating transformation and proliferation signatures. Overexpression of RIα and Cα, which upregulated PKA-I, elicited the expression signatures opposite that elicited by RIIβ overexpression. Total colocalization of Cα and RIIβ seen by confocal microscopy in the RIIβ cell nucleus supports the opposed genomic regulation demonstrated between Cα and RIIβ cells. Differential expression of PKA R subunits may therefore serve as a tumor-target-based gene therapy for PC3M prostate and other cancers.
AB - The cAMP-dependent protein kinase types I (PKA-I) and II (PKA-II), composed of identical catalytic (C) subunits but distinct regulatory (R) subunits (RI versus RII), are expressed in a balance of cell growth and differentiation. Distortion of this balance may underlie tumorigenesis and tumor growth. Here, we used PC3M prostate carcinoma cells as a model to overexpress wild type and mutant R and C subunit genes and examined the effects of differential expression of these genes on tumor growth. Only the RIIβ and mutant RIα-P (a functional mimic of RIIβ) transfectants exhibited growth inhibition in vitro, reverted phenotype, and apoptosis, and inhibited in vivo tumor growth. DNA microarrays demonstrated that RIIβ and RIα-P overexpression upregulated a cluster of differentiation genes, while downregulating transformation and proliferation signatures. Overexpression of RIα and Cα, which upregulated PKA-I, elicited the expression signatures opposite that elicited by RIIβ overexpression. Total colocalization of Cα and RIIβ seen by confocal microscopy in the RIIβ cell nucleus supports the opposed genomic regulation demonstrated between Cα and RIIβ cells. Differential expression of PKA R subunits may therefore serve as a tumor-target-based gene therapy for PC3M prostate and other cancers.
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U2 - 10.1038/sj.onc.1208165
DO - 10.1038/sj.onc.1208165
M3 - Article
C2 - 15480415
AN - SCOPUS:9944245504
SN - 0950-9232
VL - 23
SP - 8847
EP - 8856
JO - Oncogene
JF - Oncogene
IS - 54
ER -