? Worldwide, about 15% of human cancers are caused by mechanisms involving viral infection. In particular, specific types of human papillomavirus (HPV) are the principal cause of cervical cancer and its precursors. The goal of this application is to develop molecular specific contrast agents to enable low cost in vivo imaging of HPV induced cervical carcinogenesis. Most cases of cervical cancer occur in resource-poor settings, where there is insufficient infrastructure to carry out screening, diagnosis and treatment with conventional means. The molecular imaging contrast agents to be developed and tested in this application have the potential to provide sensitive and specific detection for cervical cancer and its precursors. We envision a topical delivery agent that can be applied to the cervix during a pelvic examination and interrogated using an inexpensive laser pointer (< $10 US), enabling combined screening, detection and therapy in a single visit, without the infrastructure and costs required to prepare and read Papanicolaou smears or biopsies. In the R21 phase of this application, we will show proof of concept of these contrast agents in cell and tissue culture model systems. With this reduction in risk, we will then proceed to the R33 phase of the application where a topical delivery system will be developed and pre-clinical trials will be conducted in human organ culture models and in an animal model. In the R21 phase, we will produce three different contrast agents to selectively label cells expressing high levels of two oncoproteins associated with HPV 16 induced cervical carcinogenesis: E6, and E7 and one protein associated with abnormal expression of the cell cycle, p16. Commercially available monoclonal antibodies will be conjugated to gold nanoparticles. One contrast agent will be validated in cell culture and tissue culture models. Successful completion of these experiments will demonstrate the potential for in vivo molecular imaging of a key step in cervical carcinogenesis produced by HPV infection. These pathfinder experiments have been designed to test whether specific labeling can produce strong optical signatures in model systems of progressively increasing biologic complexity. In the R33 phase of the application, these goals are extended to include the next steps required for successful clinical implementation, including a topical delivery system and pre-clinical testing in human organ culture models and an animal model. ? ?
