Abstract: Objective To discuss protein markers expressed differentially in normal cervix and cervical intraepithelial neoplasia (CIN) tissues by means of proteomics, providing the new basis to CIN molecular pathogenesis study, clinical diagnosis and treatment. Methods Uterine cervical tissue specimens were collected from the patients between August 2008 and September 2009 in Department of Oncology of Beijing Obstetrics and Gynecology Hospital, from patients with CIN (n=23, CINⅠ 7, CINⅡ 8, CINⅢ 8) and normal cervix (n=9 as controls). Two-dimensional fluorescence difference in gel electrophoresis (2-D DIGE) and DeCyder software were used to find the differentially expressed protein-spots. Then matrix- assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) was used to analyze the differentially expressed proteins and further to validate 3 strikingly differential proteins S100 calcium-binding protein A9(S100A9), eukaryotic elongation factor 1-alpha-1(eEF1A1)and pyruvate kinase M2 (PKM2) by database searching. Immunohistochemistry (IHC)(n=40, normal cervix 10、CINⅠ 10、CINⅡ 10、CINⅢ 10) and Western blotting (WB)(n=36,normal cervix=12、CINⅠ~Ⅱ 12、CIN Ⅲ~12)were used to verify the differently expressed proteins of S100A9, PKM2 and eEF1A1 between normal cervix and CIN tissues. Results CIN and normal cervix spectrometry were obtained by 2-D DIGE; and Appraisal 25 proteins successfully. IHC and Western blotting test results indicated that S100A9 protein was expressed in the cytoplasm, the expression in CIN levels were higher than that in normal group (P=0.010 ); eEF1A1 protein was expressed in cytoplasm and PKM2 protein was expressed in the nucleus, both the expressions of protein in CIN were lower than that in normal group (P = 0.352 and 0.000). Conclusion There are different protein expressions between CIN and normal cervix tissues. S100A9 protein may be regarded as a cancer marker associated with CIN; PKM2 proteins may be regarded as tumor suppression protein of CIN and the contents of these two differential proteins may help predict the development of CIN.

Key words: proteome, cervical intraepithelial neoplasia (CIN), two-dimensional fluorescence difference in gel electrophoresis(2-D DIGE), MALDI-TOF/TOF MS