Abstract
Abstract *Background:* The transcription factor PAX2 regulates key developmental processes, including mediation of resistance to apoptosis. Inappropriate PAX2 expression has been implicated in facilitating tumour survival, and we have previously shown that siRNA-mediated blockade of PAX2 signalling at the transcript level in EJ bladder carcinoma cells promotes cell death. In this study, we attempted to disrupt PAX2 transcriptional activity in EJ cells by using a decoy oligodeoxynucleotide (ODN). *Results:* We could not show an interaction between PAX2 and our PAX2 decoy ODN, and in both PAX2-positive EJ and PAX2-negative HEK293 control cells, decoy and control ODN transfection resulted in a marked retardation of cell growth, irrespective of sequence, but not in COS7 and NZM4 melanoma cells. *Conclusions:* Our data indicate that decoy ODN transfection had off-target effects that inhibited cell growth in a cell line-dependent manner, and we suggest caution is required to determine the specificity of decoy ODN sequences before considering their application as a potential therapeutic agent.
Highlights
The transcription factor PAX2 regulates key developmental processes, including mediation of resistance to apoptosis
Both mismatch and polyA negative control ODN transfections resulted in marked reduction in cell number, similar to that of PAX2 decoy ODN transfection (Fig. 1A), whereas treatment with transfection reagent alone achieved the same degree of confluency as untreated controls, suggesting that reduced cell number was not caused by transfection reagent cytotoxicity
Mismatch or polyA ODN all displayed a retarded growth rate compared to controls (Fig. 1B), suggesting that ODN treatment had a negative impact on EJ cell growth, irrespective of ODN sequence
Summary
The transcription factor PAX2 regulates key developmental processes, including mediation of resistance to apoptosis. Inappropriate PAX2 expression has been implicated in facilitating tumour survival, and we have previously shown that siRNA-mediated blockade of PAX2 signalling at the transcript level in EJ bladder carcinoma cells promotes cell death. The paired box (PAX) family of transcription factors figure prominently in key developmental processes that promote proliferation, migration, and cell lineage specification, with several PAX genes implicated in orchestrating cell survival through mediation of apoptotic resistance. RNAi-mediated knockdown of PAX2 in ovarian and bladder cancer cell lines inhibited growth and promoted apoptosis [7], whereas over-expression of PAX2 conferred apoptotic resistance in PAX2-negative HEK293 cells [8]. We have previously shown that siRNA-mediated knockdown of PAX2 transcripts causes decreased proliferation and increased apoptosis in the EJ bladder carcinoma cell line [7]. We designed a decoy ODN incorporating a consensus PAX2 DNA binding sequence, and characterised the response of transfecting decoy ODN in four cell lines including the EJ bladder carcinoma cell line
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
