[Differential analysis of two-dimension gel electrophoresis profiles of human lung squamous carcinoma and tumor-adjacent tissue].

BACKGROUND & OBJECTIVE: Carcinogenesis of lung squamous carcinoma is a complex process involving multiple events and steps. Though some molecular pathogenesis studies on human lung cancer have been undertaken successfully in gene (DNA) and transcription (mRNA) levels, the carcinogenic mechanism is still unclear. At present, there is no special molecular marker for early-stage diagnosis and prognosis evaluation. The objective of this study was to establish two-dimensional electrophoresis profiles with high resolution and reproducibility from human lung squamous carcinoma tissue and paired normal tumor-adjacent bronchial epithelial tissue, and to identify differential expression proteins.

METHODS

The total proteins of human lung squamous carcinoma tissue and paired normal tumor-adjacent bronchial epithelial tissue were separated by immobilized pH gradient (IPG)-based two-dimensional gel electrophoresis (2-DE). The differential expression proteins were analyzed using image analysis software, then identified using mass spectrometry and database searching.

RESULTS

(1) For tumor tissues, the average protein spots of 3 gels were 1349+/-67; and 1235+/-48 spots were matched with the average matching rate of 91.5%. For control, the average protein spots of 3 gels were 1297+/-73; and 1183+/-56 spots were matched with the average matching rate of 91.2%. The average position deviation of matched spots was 0.873+/-0.125 mm in IEF direction, and 1.025+/-0.213 mm in SDS-PAGE direction. (2) A total of 1069+/-45 spots were matched between the electrophoretic maps of 15 human lung squamous carcinoma tissue and paired normal tumor-adjacent bronchial epithelial tissue. Forty differential proteins were identified by peptide mass fingerprint(PMF), some proteins were the products of oncogenes, and the others involve in the regulation of cell cycle and signal transduction.

CONCLUSION

In this study, the well-resolved, reproducible 2-DE patterns of human lung squamous carcinoma and adjacent normal bronchial epithelial tissues were established and certain differential proteins were characterized. These data will be helpful for screening the biomarker to further study on human lung squamous carcinoma.