Apoptosis, growth arrest and suppression of invasiveness by CRE-decoy oligonucleotide in ovarian cancer cells: protein kinase A downregulation and cytoplasmic export of CRE-binding proteins.
The CRE (cyclic AMP response element)-transcription factor complex plays a critical role in response to hormonal signals for cell proliferation, differentiation, and apoptosis. We have reported previously that the CRE-transcription factor decoy oligonucleotide specifically slows tumor cell proliferation and inhibits CRE- and Ap-1-directed transcription in vivo (Park et al., 1999). We have investigated the effect of inhibiting CRE-directed transcription on ovarian cancer cell growth. Here, we report that CRE-decoy oligonucleotide treatment results in the inhibition of cell growth and a marked reduction in the expression of the regulatory and catalytic subunits of protein kinase A and the type I and type II protein kinase A holoenzymes. Growth inhibition was accompanied by changes in cell morphology, appearance of apoptotic nuclei, and DNA fragmentation. In addition, MMP-9 (matrix methalloproteinase-9) activity was markedly reduced in CRE-decoy treated cells. Indirect immunofluorescence revealed that CRE-decoy oligonucleotide treatment promoted export of the CRE-binding protein, CREB, from the nucleus to the cytoplasm, while importing the catalytic subunit of protein kinase A from the cytoplasm to the nucleus. The results indicate that the decoy oligonucleotide, by binding specifically to CRE-transcription factors, interferes with CRE-directed transcription in vivo. These results show a critical role for CRE-directed transcription in ovarian cancer cell growth. Thus, the CRE-decoy oligonucleotide may provide a powerful means to combat ovarian cancer.
Alper
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Cellular Biochemistry Section, Experimental Oncology Section, Laboratory of Tumor Immunology and Biology, National Cancer Institute, Bethesda, MD 20892-1750, USA.
Bergmann-Leitner
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ES
Abrams
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Cho-Chung
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YS
D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects*; D017362:Cyclic AMP Response Element-Binding Protein / Q000037:antagonists & inhibitors* / Q000235:genetics*; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018808:Transcription Factor AP-1 / Q000037:antagonists & inhibitors*; D014407:Tumor Cells, Cultured
D017362:Cyclic AMP Response Element-Binding Protein; D007527:Isoenzymes; D018808:Transcription Factor AP-1; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9