A bacterial reporter system for the evaluation of antisense oligodeoxynucleotides directed against human papillomavirus type 16 (HPV-16).

BACKGROUND: Antisense oligodeoxynucleotides (AS-ODNs) are a promising alternative for the cure of many diseases because of their in vivo specificity and stability. However, AS-ODNs have a strong dependence on the target mRNA structure making necessary extensive in vivo testing. There is, therefore, a need to develop assays to rapidly evaluate in vivo ODN performance. METHODS: We report a simple and inexpensive bacterial reporter system for the rapid in vivo evaluation of AS-ODNs directed against human papillomavirus type 16 (HPV-16) based on the destruction of a chimeric CFP mRNA using the reported HPV-16 nt 410-445 target. RESULTS: In vitro RNaseH assays confirmed target RNA accessibility after AS-ODN treatment. Expression of CFP in Escherichia coli BL21(DE3) with pGST-TSd2-CFP plasmid containing HPV-16 nt 410-445 target linked to CFP was blocked by transformed antisense PS-ODNs but not by two different scrambled ODN controls. CONCLUSIONS: A correlation was observed between bacterial CFP downregulation with the HPV-16 E6/E7 mRNA downregulation and the inhibition of anchorage-independent growth of HPV-16 containing cells suggesting that inhibition of HPV-16 E6/E7 expression by AS-ODNs directed against 410-445 target in cervical tumor cells can be tested in bacterial models.