Abstract: The invention describes use of RNA silencing suppressors or interactors of the suppressors to bring the expression of microRNAs involved in any disease, including malignant neoplasia, back to its normal level. More specifically the present invention provides a method to regulate many miRNAs at the same time. Most of the suppressors according to this invention are coded by plant viruses that unexpectedly can affect RNA silencing and modulate miRNA expression levels in mammalian cells. Also suppressors of endogenous origin are described as able to modulate miRNA expression levels.

Abstract: The invention is concerned with the use of oligonucleotide analogs that contain specifically modified DNA bases to be used in hybridization of nucleic acids, polymerase chain reaction (PCR) and siRNA-mediated gene silencing (RNAi).

Abstract: This invention discloses transgenic plants, such as transgenic tobacco and potato, having resistance to multiple viral taxonomic groups using parts of the 2,5A oligoadenylate pathway. In particular, said plants are genetically engineered to contain a DNA sequence encoding at least one polypeptide having a 2,5A synthetase activity. By this means a step in the 2,5A oligoadenylate pathway heretofore believed to be missing in all plants is provided so that viral infection in the transgenic plants is inhibited via a 2,5A dependent endonuclease. Moreover, this invention relates to a process for the production of said transgenic plants by transfection with a genetically engineered DNA sequence encoding at least one polypeptide having a 2,5A synthetase activity.