title: Generation of stable 3'-mRNA cleavage fragments induced by siRNA in cells with high-levels of duck hepatitis B virus replication.
abstract: Therapeutic small interfering RNAs (siRNAs) have attracted a lot of interest both in basic biomedical sciences as well as in translational medicine. Apart from their therapeutic efficacy adverse effects of siRNAs must be addressed. The generation of stable mRNA cleavage fragments and the translation of N-truncated proteins induced by antisense oligodeoxynucleotides (ASOs) have been reported. Similar to ASOs, siRNAs are considered to function via an antisense mechanism that promotes the cleavage of the target mRNA. To further investigate whether the stable mRNA cleavage fragments also occur in siRNA we constructed a short hairpin RNA (shRNA) expression plasmid, pshRNA794, containing the same sequence reported in experiments using ASOs which directly targeted the overlapping region of the pre-genomic mRNA (pgmRNA) and sub-genomic mRNA (sgmRNA) of duck hepatitis B virus (DHBV). The shRNA resulted in a 70.9% and 69.9% reduction of the DHBV mRNAs in LMH and HuH-7 cells, respectively. In addition a 70% inhibition of the DHBV DNA level was observed. Interestingly, 3'-mRNA cleavage fragments were detected in LMH but not in HuH-7 cells. Taken together, our findings demonstrate that the ASO sequence was also effective in siRNA. Importantly, our results provide direct evidence that stable 3'-mRNA fragments were generated by siRNA in cells with high levels of DHBV replication. Whether these can cause adverse RNAi effects needs to be explored further.
authors.affiliation: Department of Infectious Diseases, Southwestern Hospital, Third Military Medical University, Chongqing 400038, China; Department of Medicine II, University Hospital Freiburg, Freiburg D-79104, Germany. Electronic address: llin6624@gmail.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Lan
authors.affiliation: Department of Infectious Diseases, Southwestern Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Mao
authors.affiliation: Department of Medicine II, University Hospital Freiburg, Freiburg D-79104, Germany. Electronic address: hubert.blum@uniklinik-freiburg.de.
authors.forename: Hubert E
authors.initials: HE
authors.lastname: Blum
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D002460:Cell Line; D002477:Cells / Q000378:metabolism* / Q000821:virology*; D003593:Cytoplasm / Q000821:virology; D004279:DNA, Viral / Q000302:isolation & purification / Q000378:metabolism; D055785:Gene Knockdown Techniques; D015611:Hepatitis B Virus, Duck / Q000502:physiology*; D006801:Humans; D016366:Open Reading Frames / Q000235:genetics; D010957:Plasmids / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*; D014162:Transfection; D014779:Virus Replication / Q000502:physiology*
chemical_list: D004279:DNA, Viral; D012333:RNA, Messenger; D034741:RNA, Small Interfering
keywords: ASOs; DHBV; Duck hepatitis B virus; POL; RC; RISC; RNA-induced silencing complex; SS; Side effect; Small interfering RNA; antisense oligodeoxynucleotides; miRNA; microRNA; pgmRNA; polymerase; pre-genomic mRNA; relaxed circular; sgmRNA; shRNA; short hairpin RNA; siRNA; single stranded; small interfering RNA; sub-genomic mRNA