MALDI imaging approach for the diagnosis of squamous carcinoma of the cervix

Background Cervical cancer it is one of the leading causes of cancer death in women occurring worldwide. The main difficulties encountered in the diagnosis of these neoplasms are in differentiating them from high-grade squamous intraepithelial neoplasia (HSIL). Thus, there is a need to provide information on the malignant potential of dysplastic changes to estimate the biological risk. In this study, we applied imaging mass spectrometry (IMS) in an attempt to reveal distinctions between non-neoplastic, preneoplastic and neoplastic changes. Methods Formalin-fixed paraffin-embedded (FFPE) tissue sections were collected from a patient with cervical cancer. Sections were analyzed by histochemical- and immunotechniques. One section was sprayed with trypsin solution (0.5μg/μL) and subjected to matrix deposition (7 mg/ml in 50/50 acetonitrile/0.5%TFA) using an automatic spray device. Tissue section was subsequently analyzed with a high speed mass spectrometer. Spectra were acquired from a raster of laser spots with 50 μm spacing between each spot. From the image data set, mass spectra were exported from regions of interest and statistically compared through hierarchical cluster analysis. Results We use IMS technology to reveal in one single section and in one singular analysis test distinct histological features through differentially detected tryptic peptide ions. Exploring the IMS spectral data integrated with histology, we were able to correlate peptide signatures with malignant, preneoplastic and non-neoplastic squamous cells. Conclusions Our findings provide a new molecular strategy to supplement the current histopathological analysis of cervical cancer, and may be helpful for better understanding aggressiveness and progression of the disease. Further studies will be carried out to validate our results.