Selection and cloning of poly(rC)-binding protein 2 and Raf kinase inhibitor protein RNA activators of 2',5'-oligoadenylate synthetase from prostate cancer cells.
The antiviral and antitumor functions of RNase L are enabled by binding to the allosteric effectors 5'-phosphorylated, 2',5'-linked oligoadenylates (2-5A). 2-5A is produced by interferon-inducible 2',5'-oligoadenylate synthetases (OAS) upon activation by viral double-stranded RNA (dsRNA). Because mutations in RNase L have been implicated as risk factors for prostate cancer, we sought to determine if OAS activators are present in prostate cancer cells. We show that prostate cancer cell lines (PC3, LNCaP and DU145), but not normal prostate epithelial cells (PrEC), contain RNA fractions capable of binding to and activating OAS. To identify the RNA activators, we developed a cDNA cloning strategy based on stringent affinity of RNAs for OAS. We thus identified mRNAs for Raf kinase inhibitor protein (RKIP) and poly(rC)-binding protein 2 (PCBP2) that bind and potently activate OAS. In addition, human endogenous retrovirus (hERV) envelope RNAs were present in PC3 cells that bind and activate OAS. Analysis of several gene expression profiling studies indicated that PCBP2 RNA was consistently elevated in metastatic prostate cancer. Results suggest that OAS activation may occur in prostate cancer cells in vivo stimulated by cellular mRNAs for RKIP and PCBP2.
Molinaro
Ross J
RJ
Department of Chemistry, Cleveland State University, Euclid Avenue at East 24th Street, Cleveland, OH 44115, USA.
Jha
Babal Kant
BK
Malathi
Krishnamurthy
K
Varambally
Sooryanarayana
S
Chinnaiyan
Arul M
AM
Silverman
Robert H
RH
D015088:2',5'-Oligoadenylate Synthetase / Q000378:metabolism*; D000227:Adenine Nucleotides / Q000737:chemistry; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D020077:Endogenous Retroviruses / Q000235:genetics; D004789:Enzyme Activation; D015686:Gene Products, env / Q000235:genetics; D006801:Humans; D008297:Male; D009843:Oligoribonucleotides / Q000737:chemistry; D049488:Phosphatidylethanolamine Binding Protein / Q000235:genetics* / Q000378:metabolism; D011467:Prostate / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism
D000227:Adenine Nucleotides; D015686:Gene Products, env; D009843:Oligoribonucleotides; C501903:PCBP2 protein, human; C511482:PEBP1 protein, human; D049488:Phosphatidylethanolamine Binding Protein; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012367:RNA, Viral; D016601:RNA-Binding Proteins; C023505:2',5'-oligoadenylate; C475085:OAS1 protein, human; D015088:2',5'-Oligoadenylate Synthetase