OBJECTIVETo identify differentially expressed genes in human embryo lung fibroblasts MRC-5 with adaptive response induced by low concentration of hydrogen peroxide (H(2)O(2)) using fluorescent differential display-RT-PCR (FDDRT-PCR).

METHODSThe dose-effect pattern of H2O2 toxicity was determined using MTT assay, and the dose of 0.088, 0.88, 8.8, 88 micro;mol/L was defined as the low concentration, and 1100 micromol/L as the high concentration. Adaptive response model was established in MRC-5 cells verified using LDH release and cell apoptosis analyses. Differentially expressed genes in the cells with exposure to different doses of H(2)O(2) were detected by FDDRT-PCR, and some of the differentially displayed genes were determined using real-time quantitative PCR.

RESULTSCells challenged with high-concentration H(2)O(2) for 1 h after H(2)O(2) pretreatment at low concentrations for 24 h resulted in lessened toxic effect in comparison with direct high-concentration H(2)O(2) exposure. The adaptive response of the cells was most obvious with H(2)O(2) pretreatment at 0.88 micromol/L. Altogether 60 differentially expressed genes were detected with FDDRT-PCR in different treatment groups, and 5 of them were identified and verified, including 1 unknown gene and 4 known genes (bcl-2, EIF3S5, NDUFS4 and RPS10).

CONCLUSIONAccording to the results of FDDRT-PCR, the genes bcl-2, EIF3S5, NDUFS4 and RPS10 can be involved in H(2)O(2)-induced adaptive response of the MRC-5 cells.