Fluorescence spectroscopy of an in vitro model of human cervical neoplasia identifies graded spectral shape changes with neoplastic phenotype and a differential effect of acetic acid

Background: The clinical utility of spectroscopic methods for the diagnosis of cervical cancer is limited by significant inter-patient variation in the spectroscopic properties of the cervix. Improved understanding of the contributions of the components of cervical tissue to the observed spectra would therefore be helpful in the development of spectroscopic approaches to the study of cervical disease in vivo. Methods: in this study, we used organotypic epithelial raft Culture as an in vitro model system to analyse the fluorescence properties of the surface squamous epithelium specifically. The spectrum of cervical dysplasia was modelled by producing rafts lined by primary human keratinocytes (PHKs) and the HaCaT, SiHa and CaSki human keratinocyte cell lines and fluorescence emission spectra were recorded at a wide range of excitation wavelengths. Results: Statistically significant differences in spectral shape were identified between the different rafts at excitation wavelengths between 250 nm and 310 nm. A graded, differential effect of acetic acid on fluorescence intensity was also observed, consistent with the visible effects of acetic acid on clinical examination at colposcopy. Conclusion: These data suggest that the development of neoplastic changes in the squamous epithelium of the cervix are associated with alterations in its fluorescence properties and that the application of acetic acid has a demonstrable effect on these properties. Identification of these alterations may aid the discrimination of cervical lesions in vivo. (C) 2009 Elsevier Ltd. All rights reserved.