Abstract: OBJECTIVE：This study aimed to identify the biological characteristics of SET protein- deficient L-02 cells which could lay a foundation for the role of SET protein in normal L-02 cells. METHODS：Normal L-02 cells，SET protein-deficient L-02 cells (stably expressing SET siRNA)，siRNAc transfected L-02 cell were cultured and the growth and the morphology of these three groups of cells were examined and analyzed. The growth curves of the cells were generated on the data from MTT assay. Chromosome structure was detected by chromosome aberration analysis. Malignant transformation was identified by soft agar cloning test. RESULTS： Compared with normal L-02 cells，no obvious changes of cytomorphology and growth curves were observed for SET protein- deficient L-02 cells and siRNAc transfected L-02 cells. Chromosome aberration analysis revealed that transfection of SET siRNA did not cause obvious changes in the structure and numbers of chromosomes in L-02 cells. Soft agar cloning test showed that transfection of SET siRNA did not cause malignant transformation of the cells. CONCLUSION：Transfection of SET siRNA did not significantly alter the biologic characteristics of the cells，indicating that the established SET-deficient cells can be used as a model for further studies.

Key words: trichloroethylene, SET protein- deficient L-02 cells, biological characters, cell proliferation