[Expression and significance of X-linked inhibitor of apoptosis protein and its antagonized proteins in acute leukemia].

To investigate the expression and significance of X-linked inhibitor of apoptosis protein (XIAP) and XIAP-associated factor 1 (XAF1) in acute leukemia, the expression of XIAP, XAF1, Smac, and HtrA2 mRNA in the bone marrow aspirates from 87 newly diagnosed AL patients, 23 patients in remission, 6 patients in relapse, and 17 normal controls were detected by means of reverse transcriptase polymerase chain reaction (RT-PCR), and their relationship with clinical therapeutic efficiency was analyzed. The results showed that the expression level of XIAP mRNA in newly diagnosed AL patients (0.990 +/- 0.337) was significantly higher than that in normal controls (0.395 +/- 0.148) (P < 0.01); the positive rate and expression level of XAF1 mRNA in newly diagnosed AL patients (56.32%, 0.246 +/- 0.267) were significantly lower than that in normal controls (100%, 0.964 +/- 0.387) (P < 0.01). In 69 out of 87 newly diagnosed AL patients, efficacy remained evaluable. AL patients with high level of XIAP achieved a lower complete remission (CR) rate than patients with low level of XIAP (54.55% and 86.11%, respectively) (P < 0.01). XAF1 positive patients achieved a higher CR rate than XAF1 negative patients (86.84% and 51.61%, respectively) (P < 0.01). It is concluded that the overexpression of XIAP and negativity of XAF1 may be two adverse prognostic factors in AL patients.