Objective        To study the effect of spermidine/spermine N

1

-acetyltransferase 2 (SSAT2) on the proliferation and apoptosis in renal carcinoma Caki-1 cells and cell sensitivity to adriamycin under hypoxic condition.       Methods        Plasmid pcDNA3.1(D)/V5-His-SSAT2 was transfected into Caki-1cells with X-treme GENE HP. Caki-1 cells were cultured under hypoxia condi

tion. Expression of SSAT2 and hypoxia-inducible factor-1 alpha (HIF-1α) protein was detected by Western blotting. Apoptotic and necrotic rates of Caki-1 cells were assayed by flow cytometry. Proliferation of Caki-1 cells and inhibitory effect of adriamycin on proliferation of Caki-1 cells were detected by MTT assay.       Results        The SSAT2 was successfully transfected into Caki-1 cells. The expression level of HIF-1α  and the proliferation level of Caki-1 cells were significantly lower while the apoptotic and necrotic rates of Caki-1 cells were significantly higher in SSAT2 transfection group than in blank cell group and empty vector group (P0.01）. The inhibitory rate of adriamycin on SSAT2 transfected Caki-1 cells could reach (67.5±3.7)%

while only (54.7±8.4)% and (56.8±7.7)% respectively in blank cell group and empty vector group when adriamycin was administrated at the concentration of 2 μg/ml (P0.01）.       Conclusion        SSAT2 inhibits the proliferation and improves the apoptotic and necrotic rates of Caki-1 cells

enhances the sensitivity of Caki-1 cells to adriamycin by down-regulating the expression of HIF-1α protein. SSAT2 targeting therapy may thus become one of the methods for reversing the drug-resistance of renal carcinoma．