Impact of RNase L overexpression on viral and cellular growth and death.
The biologic actions of interferons (IFNs) are complex and involve multiple biochemical mechanisms, including the 2-5A system, a regulated RNA decay pathway. The 2-5A system is implicated in the antipicornavirus activity of IFN and in the control of apoptosis. To further investigate involvement of the 2-5A system in the control of viral and cellular growth and death, human RNase L cDNA was stably expressed in murine 3T3 cells from a constitutive cytomegalovirus (CMV) promoter. A clonal cell line, 3T3/pLZ, was isolated that overexpressed RNase L by >100-fold compared with levels of the endogenous murine RNase L. Interestingly, human RNase L levels in 3T3/pLZ cells decreased 3-fold as cells entered a confluent, growth arrest state, suggesting autoregulation. Overexpression of human RNase L greatly enhanced both the cell growth inhibitory activity of IFN and the proapoptotic activity of staurosporine. Furthermore, high levels of RNase L suppressed the replication of diverse viruses: encephalomyocarditis virus, vesicular stomatitis virus, human parainfluenza virus-3, and vaccinia virus. Additional reductions in viral growth were obtained by treating 3T3/pLZ cells with IFN (a + beta) before infections. These results directly demonstrate the anticellular and antiviral potential of the 2-5A system.
Zhou
A
A
Department of Cancer Biology, The Lerner Research Institute, Cleveland Clinic Foundation, OH 44195, USA.
Paranjape
J M
JM
Hassel
B A
BA
Nie
H
H
Shah
S
S
Galinski
B
B
Silverman
R H
RH
D016475:3T3 Cells; D000227:Adenine Nucleotides / Q000494:pharmacology*; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016923:Cell Death / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D004722:Endoribonucleases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D051379:Mice; D009843:Oligoribonucleotides / Q000494:pharmacology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D019311:Staurosporine / Q000494:pharmacology
D000227:Adenine Nucleotides; D000998:Antiviral Agents; D009843:Oligoribonucleotides; D011500:Protein Synthesis Inhibitors; C023505:2',5'-oligoadenylate; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease; D019311:Staurosporine