Midkine和Caspase-3在胰腺癌中的表达与细胞凋亡的关系

Expression of Midkine and Caspase-3 and their relationship with apoptosis in pancreatic cancer

目的:研究人胰腺癌组织中Midkine(MK)和Caspase-3蛋白的表达特点,探讨其表达与胰腺癌细胞凋亡的关系.方法:收集人胰腺癌组织标本49例,免疫组织化学SP法检测MK和Caspase-3蛋白的表达,原位凋亡检测试剂盒辣根过氧化物酶(TUNEL)检测细胞凋亡指数.以同期15例正常胰腺组织标本为对照.结果:MK蛋白、Caspase-3蛋白在胰腺癌组织中的阳性表达率高于正常胰腺组织(71.4%vs0,P<0.01;77.6%vs46.7%,P<0.05),MK蛋白表达与胰腺癌组织学分化、临床分期和淋巴转移相关(P<0.05),Caspase-3蛋白表达仅与组织学分化有关;胰腺癌组织标本中,MK阳性表达组凋亡指数显著低于MK阴性表达组(5.13±2.69vs7.93±6.65,P<0.05);胰腺癌组织中MK与Caspase-3蛋白的表达呈负相关(r=-0.34,P<0.05).结论:MK和Caspase-3参与了胰腺癌的发生发展,MK在胰腺癌组织中的高表达具有抑制细胞凋亡的生物学功能,其作用机制可能是通过抑制Caspase-3的活性.

AIM： To study the expression of Midkine （MK） protein and Caspase-3 protein in human pancreatic cancer and to investigate their association with cell apoptosis. METHODS： The immunohistochemical staining （SP） method was used to detect the expression of MK protein and Caspase-3 in 49 cases of pancreatic cancer tissues and 15 cases of normal pancreatic tissues. The TUNEL method was used to detect apoptotic index in pancreatic cancer tissues. RESULTS： The positive rates of MK protein and Caspase-3 protein were significantly higher in pancreatic cancer tissue than in normal pancreatic tissue （71.4% vs 0, P 〈 0.01; 77.6% vs 46.7%, P 〈 0.05）. Expression of MK protein was correlated with tumor＇s histological grading, clinical stages and lymph node metastasis （P 〈 0.05） while expression of Caspase-3 protein was only correlated with tumor＇s histological grading （P 〈 0.05）. The mean apoptotic index was significantly lower in MK positive expression group than in MK negative expression group （5.13 ± 2.69 vs 7.93 ± 6.65, P 〈 0.05）. The expression level of MK protein had a negative correlation with Caspase-3 （r = -0.34, P 〈 0.05）. CONCLUSION： The gene of Midkine and Caspase-3 participate in development of pancreatic cancer, and high express of Midkine has a biological function of inhibiting cell apoptosis possibly through suppressing cell activity of Caspase-3 protein.