Open Access Open Badges Research

Antisense RNA directed to the human papillomavirus type 16 E7 mRNA from herpes simplex virus type 1 derived vectors is expressed in CaSki cells and downregulates E7 mRNA

Ilkka Kari123, Stina Syrjänen23, Bo Johansson237, Piritta Peri1, Bin He46, Bernard Roizman4 and Veijo Hukkanen125*

Author Affiliations

1 Department of Virology, Institute of Dentistry, University of Turku, Turku, Finland

2 MediCity Research Laboratory, Institute of Dentistry, University of Turku, Turku, Finland

3 Department of Oral Pathology, Institute of Dentistry, University of Turku, Turku, Finland

4 The Marjorie B. Kovler Viral Oncology Laboratories, The University of Chicago, Chicago, IL, USA

5 Department of Microbiology, University of Oulu, Oulu, Finland

6 Department of Microbiology and Immunology, University of Illinois, Chicago, IL, USA

7 Department of Clinical Virology, Karolinska University Hospital, Stockholm, Sweden

For all author emails, please log on.

Virology Journal 2007, 4:47  doi:10.1186/1743-422X-4-47

Published: 4 June 2007



Human papillomavirus (HPV) infection is known to be the most important etiologic factor of cervical cancer. There is no HPV specific therapy available for treatment of invasive squamous cell carcinoma of the cervix and its precursor lesions. The present study elucidates the potential to use herpes simplex virus (HSV) derived vectors for expression of antisense RNA to HPV -16 E7 oncogene.


We have constructed replication competent, nonneuroinvasive HSV-1 vectors, deleted of the γ134.5 gene. The vectors express RNA antisense to the first 100 nucleotides of the HPV-16 E7 gene. We assayed the ability of the antisense E7 vectors R5225 (tk-) and R5226 (tk+), to produce antisense RNA, as well as the consequent effects on E7 mRNA and protein levels in HPV-16 positive CaSki cells. Anti-E7 RNA was expressed by both constructs in a dose-dependent manner. Expression of HPV-16 E7 mRNA was downregulated effectively in CaSki cells infected with the tk- recombinant R5225 or with R5226. The tk+ recombinant R5226 was effective in downregulating E7 protein expression.


We have shown that anti-E7 RNA expressed from an HSV vector could efficiently downregulate HPV-16 E7 mRNA and E7 protein expression in CaSki cells. We conclude that HSV vectors may become a useful tool for gene therapy of HPV infections.