Abstract: BACKGROUND AND AIM: To screen the marker genes related to oral leukoplakia,laying foundation for the research in the genetic mechanism of oral leukoplakia. MATERIALS AND METHODS: In order to identify marker gene candidates, differential gene expression between normal tissues and precancerous oral tissues were examined by Oligo Cancer Microarray(SuperArray,USA).We further validated several positively expressed genes by RT-PCR,searching for the related genes which participated in malignant transformation.Total RNAs were isolated from two tissues, Chemiluminescent Detection Kit (SuperArray Bioscience, catalog number D-01),X-ray film and GEArray Expression Analysis Suite(supplied on internet) were used to analyze the genechips. In order to quantitate the expression level of the chosen genes in RT-PCR,Kodak Gel image analysis system was used.Lastly,we made a correlation analysis on the results of these two technologies. RESULTS: RT-PCR showed that the expression Levels of CTNNB1,GDF15,FKBP8 and NF1 genes differed significantly between the precancerous tissues and the normal tissues(P<0.05).The genechip test confirmed these results(P<0.05):the genetic mechanisms of oral leukoplakia were very complicated,particularly associated with cell cycle regulation genes and cell growth and differentiation genes. CONCLUSION: This research formed the basis for further studies of the genetic mechanisms of oral leukoplakia and marker gene screening.

Key words: oral leukoplakia, genechip, gene expression