OBJECTIVETo investigate the expressions and significances of Survivin and Smac in ovarian mucinous tumors.

METHODSA total of 55 paraffin-embedded specimens of primary ovarian mucinous tumors were collected. SABC was used to detect protein expression of Survivin and Smac genes. Immunoelectron microscopy using colloidal gold labeling was performed to determine the subcellular localization and patterns of Smac protein expression.

RESULTS(1) The cytoplasmic expression rates of survivin in benign, borderline and malignant ovarian mucinous tumors were 2/20, 12/15 and 20/20 respectively, which presents an improving trend.There were significant differences of survivin expression between benign vs. borderline lesions (P < 0.01), and benign vs. malignant tumors (P < 0.01). The nuclear expression rates of survivin in benign, borderline and malignant ovarian mucinous tumors were 1/20, 6/15 and 5/20, respectively, which presents a.declining trend.There was significant difference of survivin expression between benign vs. borderline tumors (P < 0.05). The positive expression rates of Smac among the three groups were 19/20, 9/15 and 3/20, respectively. There was significant difference among the three groups (P < 0.01 or < 0.05). There was a negative correlation between Survivin and Smac (r = -0.153, P < 0.01). (2) Colloidal gold labeling study demonstrated that mitochondrion intramembranous storage of Smac granules in the three groups were 24.1 ± 7.2, 11.1 ± 1.9 and 5.2 ± 1.7, respectively, and there were significant differences among the three groups (P < 0.01 or < 0.05). The extramemebranous Smac granules were 4.7 ± 3.0, 2.9 ± 1.0 and 1.7 ± 1.3, although without significant difference among the three groups (P > 0.05).

CONCLUSIONSWith the malignant development of ovarian mucinous tumors, the expressions of Survivin are up-regulated, and the expressions of Smac are down-regulated. Smac proteins exist mainly in an inactive intramembranous storage form inside of mitochondria.