Thin Prep Gel-Based Proteomics Approach: New Methodology to Give Protein Signature in Residual Cervical Cytology Samples

Human Papillomavirus (HPV) DNA test improved the effectiveness of Cervical Cancer Screening Programs, but it frequently leads to unnecessary follow-up and treatments in potentially regressing lesions. The presence of HPV oncoproteins, named E6 and E7, is a key event resulting from persistent infection, besides other factors are certainly involved. Proteomics represents a promising tool to precociously identify the possible changes occurring during cervical carcinogenesis and to better understand the natural history of HPV-related cancer. The suitability of PreservCyt medium for gelbased proteomic analysis has not been tested yet. This study aimed to build a healthy cervix reference map by two-dimensional Matrix-Assisted Laser Desorption/Ionization time-of-flight mass spectrometry (2DE MALDI-TOF MS) starting from Thin Prep cervical specimens. The first step was to compare residual and whole specimens in terms of protein recovery, the second being the assessment of the influence of storage duration on proteomic analysis. Image analysis of 2DE gel identified a similarity of 87% between residual and whole samples. Protein recovery drastically decreased when storage duration increased. Many of the proteins identified in study samples are constitutively present in healthy cervix. Thin Prep cervical samples are suitable for proteomic analysis. The “one sample for all” approach confirms to be possible.