Raman Spectroscopy: A Novel Tool for Cervical Cancer Screening
KM Ostrowska, A Malkin, HJ Byrne, C Martin, JJ O'Leary, FM Lyng. Dublin Institute of Technology, Dublin, Ireland; Coombe Women and Infants University Hospital, Dublin, Ireland
Background: Cervical cancer is the second most common cancer in women worldwide. The Papanicolaou test is used to detect cancer and pre-cancer in the general female population but it is widely acknowledged that sensitivity values are low. The aim of this study was to investigate the potential of Raman spectroscopy to detect biochemical changes in cervical smear samples. The ability of Raman spectroscopy to classify different cell types, discriminate between nuclear and cytoplasmic regions of squamous epithelial cells and between normal and abnormal cervical cells was investigated. Four cervical cancer cell lines were also investigated to determine if cell lines with different HPV copy number could be discriminated.
Design: Cervical smear samples were obtained from CWIUH. C33A (HPV negative), HeLa (HPV-18 positive, 20-50 copies per cell), SiHa (HPV-16 positive, 1-2 copies per cell) and CaSki (HPV-16 positive, 60-600 copies per cell) cells were cultured on glass slides. Raman measurements were carried out using a Horiba JY Labram HR800 Raman microscope. After Raman measurements, cells were stained with Papanicolaou stain, coverslipped and submitted for cytological examination. Subsequently, the Raman spectra were analysed using Principal Component Analysis (PCA), a multivariate statistical technique.
Results: The Raman spectra showed differences in the glycogen, protein and nucleic acid levels of superficial epithelial cells, navicular cells and polymorphs, as well as between the nucleus and cytoplasm of superficial squamous epithelial cells. In the abnormal cervical cells, a significant increase in nuclear activity was observed, as indicated by an increase in the intensity of peaks assigned to nucleic acids. The cervical cell lines showed distinct differences in their Raman spectra. Principal Component Analysis (PCA) successfully discriminated different classes of cervical cells, cell regions, and normal from abnormal cells. In addition, the cervical cell lines were discriminated by PCA based on their HPV copy number.
Conclusions: The results show clearly that Raman spectroscopy can be used for identification and discrimination of normal and abnormal cervical cells. Moreover, HPV positive and negative cell lines could be discriminated based on their biochemical fingerprint. Raman spectroscopy thus shows enormous clinical potential for cervical cancer screening.
Tuesday, March 23, 2010 9:30 AM
Poster Session III # 73, Tuesday Morning