胰岛素样生长因子Ⅰ型受体在恶性血液病骨髓有核细胞的表达及其抗凋亡作用

为探索胰岛素样生长因子Ⅰ型受体(IGF-IR)在骨髓增生异常综合征(MDS)和急性髓细胞白血病(AML)骨髓有核细胞表面的表达及其与细胞凋亡的关系,收集MDS和AML患者各16例骨髓有核细胞,经离心涂片机制片,用免疫酶标记方法(APAAP)及TdT凋亡检测(TUNEL)法先后在同一标本上检测IGF-IR表达和凋亡信号,并以16名正常人骨髓有核细胞作对照.结果显示①MDS组骨髓细胞IGF-IR表达(56.8±14.3)%]高于正常对照(40.4±9.6)%](P＜0.01),AML组骨髓细胞IGF-IR表达(86.8±13.8)%]高于正常对照(P＜0.01),AML骨髓细胞IGF-IR表达高于MDS骨髓细胞(P＜0.01);②MDS组骨髓细胞凋亡率为(5.4±3.0)%]高于正常对照(1.2±0.9)%](P＜0.01),AML组骨髓细胞凋亡率为(0.3±0.4)%]低于正常对照(P＜0.01),MDS组细胞凋亡率明显高于AML组(P＜0.01);③细胞凋亡主要发生在IGF-IR阴性细胞(9.0±4.8)%],IGF-IR阳性细胞中凋亡细胞仅占(1.4±2.4)%](P＜0.01),IGF-IR表达与细胞凋亡呈负相关(r=-0.852;P＜0.01);④MDS骨髓细胞IGF-IR表达阳性率RAEB/RAEB-t/CMML组高于RA/RAS组,分别为(64.1±3.2)%和(53.5±16.2)%,但差异无显著性,细胞凋亡率RAEB/RAEB-t/CMML组低于RA/RAS组,分别为(3.1±2.1)%和(6.4±2.8)%,(P＜0.05);⑤MDS和AML中IGF-IR阳性率与原始细胞百分比存在明显的正相关(r=0.677;P＜0.01).结论MDS和AML造血细胞过度表达IGF-IR.IGF-IR表达增高可能预示造血细胞的恶性增殖倾向并通过某种途径抑制细胞凋亡.如果能证实此点,则抗IGF-IR治疗有希望成为治疗MDS和AML的新方法.

Expression of Insulin-like Growth Factor Receptor Type Ⅰ in Marrow Nucleated Cells from Hematologic Malignancies and Its Anti-apoptotic Effect

To explore the expression of insulin-like growth factor receptor type I (IGF-IR) and its relationship to apoptosis in hematopoietic cells of MDS and AML marrow, bone marrow nucleated cells from 16 patients with myelodysplastic syndrome (MDS) and 16 patients with acute myeloid leukemia (AML) were collected for analysis, respectively. Another 16 normal donors' marrow samples were taken as controls. Immunocytochemical method (APAAP) and TdT-mediated dUTP nick end labeling (TUNEL) fluorescence were used simultaneously on cytospins of nucleated cells from these patients. Then, the ratios of IGF-IR positive cells and apoptosis cells in all nucleated cells were counted separately. The results showed that (1) there was a higher IGF-IR expression rate (56.8 +/- 14.3)% in nucleated cells of MDS marrow than that in normal marrow (40.4 +/- 9.6)% (P < 0.01). Also IGF-IR positive rate in AML marrow (86.8 +/- 13.8)% was significantly higher than that in normal marrow (P < 0.01). Furthermore, IGF-IR had higher expression in AML marrow when compared to MDS marrow (P < 0.01); (2) apoptosis in nucleated cells of MDS marrow (5.4 +/- 3.0)% was significantly higher than that in normal marrow (1.2 +/- 0.9)% (P < 0.01) and AML marrow (0.3 +/- 0.4)% (P < 0.01), while there was less apoptosis in AML marrow than that in normal marrow (P < 0.01); (3) apoptosis occurred mainly in IGF-IR negative cells (9.0 +/- 4.8)% and less in IGF-IR positive cells (1.4 +/- 2.4)% (P < 0.01). IGF-IR expression showed negative correlation with apoptosis (r = -0.852, P < 0.01); (4) IGF-IR of MDS nucleated cells in RAEB/RAEB-t/CMML expressed higher than that in RA/RAS (64.1 +/- 3.2% vs 53.5 +/- 16.2%) subgroup, although no significant difference was found (P > 0.05); and apoptosis in RAEB/RAEB-t/CMML subgroup was lower than that in RA/RAS cases (3.1 +/- 2.1% vs 6.4 +/- 2.8%) (P < 0.05); (5) IGF-IR positive rate in nucleated cells of MDS and AML marrow showed positive correlation with blast rate (r = 0.677; P < 0.01). It is concluded that there is overexpression of IGF-IR in marrow nucleated cells in MDS and AML cases. And it seems that the overexpression of IGF-IR may suggest some malignant proliferation tendency and suppress cell apoptosis through some mechanism in these malignant hematologic ailments. So, anti-IGF-IR will become a new approach for therapy of MDS and AML.