Changes in gene expression induced by phosphorothioate oligodeoxynucleotides (including G3139) in PC3 prostate carcinoma cells are recapitulated at least in part by treatment with interferon-beta and -gamma.
OBJECTIVE
G3139 is an antisense bcl-2 phosphorothioate oligodeoxyribonucleotide that is currently being evaluated in Phase III clinical trials in several human cancers. The aim of the present work was to further identify the apparent non-bcl-2-dependent mechanism of this action of this compound in PC3 prostate cancer cells.


METHODS
We performed Affymetrix U95A oligonucleotide microarray studies on mRNA isolated from cells treated with G3139 and related oligonucleotides.


RESULTS
Hierarchical clustering revealed the presence of a set of genes of which the expression was elevated on both 1 and 3 days after oligonucleotide treatment. Significantly, the persistence of expression of the up-regulation of these genes, many of which are members of the IFN cascade, was greater for G3139 than for any other oligomer evaluated. Furthermore, many of the genes with the greatest up-regulation of expression are also those of which the expression is up-regulated after treatment of cells with IFNs. Treatment of PC3 cells with either IFN-beta or -gamma recapitulated some of the aspects of the molecular and phenotypic changes observed after treatment with a G3139/Lipofectin complex. These include down-regulation of bcl-2 protein expression itself, down-regulation of protein kinase C alpha protein expression (but not that of other protein kinase C isoforms), alteration in p21/Waf1/Cip1 protein expression, up-regulation of MHC-I cell surface expression, and profound suppression of cell growth in the absence of a notable increase in cellular apoptosis. However, G3139 (when complexed with Lipofectin) did not induce the up-regulation of expression of either type I or type II IFNs, nor could IFNs be found in conditioned media from treated cells.


CONCLUSIONS
Oligonucleotide microarray experiments demonstrated that G3139 could induce elements of the IFN cascade in PC3 cells in vitro. In addition, the cellular phenotype obtained after treatment with exogenous IFN could, at least in part, recapitulate that obtained after G3139 treatment. Nevertheless, the oligonucleotide microarray experiments we performed also demonstrated that there are extremely large qualitative and quantitative differences between the two treatments.
Benimetskaya
Luba
L
Department of Medicine, Columbia University, New York, New York, USA.
Wittenberger
Timo
T
Stein
C A
CA
Hofmann
Hans-Peter
HP
Weller
Claudia
C
Lai
Johnathan C
JC
Miller
Paul
P
Gekeler
Volker
V
D000465:Algorithms; D017304:Annexin A5 / Q000737:chemistry; D000911:Antibodies, Monoclonal / Q000737:chemistry; D015152:Blotting, Northern; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D016000:Cluster Analysis; D018899:CpG Islands; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D016899:Interferon-beta / Q000627:therapeutic use*; D007371:Interferon-gamma / Q000378:metabolism / Q000627:therapeutic use*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D009841:Oligonucleotides / Q000627:therapeutic use*; D010641:Phenotype; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000628:therapy*; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000096:biosynthesis; D051571:Protein Kinase C-alpha; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation
D017304:Annexin A5; D000911:Antibodies, Monoclonal; D009841:Oligonucleotides; D020033:Protein Isoforms; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D016899:Interferon-beta; D007371:Interferon-gamma; C496628:PRKCA protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha