Screening for differentially expressed proteins in nasopharyngeal carcinoma by laser capture microdissection and proteomic analysis / 中南大学学报(医学版)

OBJECTIVE@#To search for the differentially expressed proteins of nasopharyngeal carcinoma (NPC),and provide scientific evidence for identifying molecular biomarkers for NPC.@*METHODS@#Laser capture microdissection (LCM) was used to purify the target cells from NPC and normal nasopharyngeal epithelial tissues (NNET). Two-dimensional gel electrophoresis (2-DE) was used to separate the total proteins of microdissected NPC and NNET, PDQuest software was applied to analyze 2-DE images,and the differential proteins between the 2 types of tissues were identified by both MALDI-TOF-MS and ESI-Q-TOF-MS. Western blot and immunohistochemistry of tissue microarray were used to detect the expression of the differential protein SCCA1 in NPC and NNET.@*RESULTS@#2-DE patterns of microdissected NPC and NNEC were established,and 36 differential proteins in the NPC and NNEC were identified,20 of which only expressed or up-regulated in NPC and 16 only expressed or up-regulated in NNET. The differentially expressed level of SCCA1 in the NPC and NNET was confirmed by Western blot and immunohistochemistry of tissue microarray.@*CONCLUSION@#Thirty-six differentially expressed proteins identified in this study may be associated with the carcinogenesis of NPC,and may be candidate molecular biomarkers for NPC.

Differential proteomic analysis of nasopharyngeal carcinoma cell lines 5-8F and 6-10B / 中南大学学报(医学版)

OBJECTIVE@#To compare the proteome difference of nasopharyngeal carcinoma (NPC) cell lines 5-8F and 6-10B, and to screen these proteins associated with NPC metastasis.@*METHODS@#Two-dimensional gel electrophoresis (2-DE) was used to separate the total proteins from NPC cell lines 5-8F and 6-10B with different metastatic potentials and same genetic background, respectively. PDQuest software was applied to analyze 2-DE images, and the differentially expressed protein spots between 5-8F and 6-10B were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The expression levels of partial identified proteins in the 2 cell lines were detected by Western blot.@*RESULTS@#2-DE maps of total proteins from 5-8F and 6-10B were established. A total of 65 differential protein spots in the 2 cell lines were found, and 15 non-redundant differential expression proteins were identified by MALDI-TOF-MS. Western blot showed that Annexin A1 and 14-3-3 protein sigma were differential expression proteins in 5-8F and 6-10B, which was consistent with the Results from the comparative proteomic analysis.@*CONCLUSION@#Fifteen non-redundant differential expression proteins are useful for studying the metastatic mechanism of NPC.

Establishment of protein expression profile of human normal colonic epithelia / 中南大学学报(医学版)

OBJECTIVE@#To establish a protein expression profile of human normal colonic epithelia.@*METHODS@#Two-dimensional gel electrophoresis (2-DE) was applied to separate the total proteins of 20 human normal colonic epithelial tissues. The expression proteins in the human normal colonic epithelia were identified by both matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and electrospray ionization tandem mass spectrometry (ESI-Q-TOF), and the biological function and subcellular locations of the identified proteins were analyzed by bioinformatics.@*RESULTS@#A 2-DE reference map of human normal colonic epithelium was established. On the 2-DE map, 1020+/-50 protein spots were detected, 204 protein spots representing 162 non-redundant proteins were identified, and 37 proteins had posttranslational modification. The identified proteins were categorized into several protein groups according to their functions or subcellular locations, whose data were available at our website (http://www.xyproteomics.org).@*CONCLUSION@#A protein expression profile of human normal colonic epithelia is established for the first time, which provides useful information for investigating the physiological functions and pathologic process of colonic epithelia.