Fig. 1

Screen and identification of stathmin expression in OSCC cell lines and tissue samples. Using 2-DE and silver staining, comparing to the human immortalized oral epithelial cells (a), overexpressed protein spot (Molecular Weight = 17,171.39 Da, pI = 5.77) was found in the derived cancerous cell line of HB96 (b). The peptide fingerprint of the differentially expressed spot was identified by MALDI-TOF MS/MS (c, d). Protein identification with the MS/MS raw data was performed as stathmin using the SEQUEST program in the BioWorks 3.1 software suite (University of Washington, licensed to Thermo Finnigan) based on the IPI Human database version 3.15.1 (e). The reference amino acids sequence of stathmin was shown with underlined characters (f). Representative images show immunohistochemical staining against stathmin in poorly, moderately, and well differentiated OSCC, and normal oral mucosa tissue. Original magnification: ×200 (g). The stathmin IHC score in OSCC patients was higher than normal controls (h). Stathmin expression was detected in tumor (T) and paracancerous (P) tissues from five OSCC patients (P) using western blot (i). Overexpression of stathmin at the mRNA and protein levels was confirmed in OSCC lines compared to the normal oral mucosa (j, k)