甲硫腺苷磷酸化酶基因和鸟氨酸脱羧酶在卵巢癌中的表达及意义

目的： 研究甲硫腺苷磷酸化酶（MTAP）基因和鸟氨酸脱羧酶（ODC）在卵巢癌中的表达，探讨两者与卵巢癌发病机制的关系。方法：收集60例新鲜的卵巢癌组织。采用逆转录聚合酶链反应测定癌组织中MTAP mRNA的表达,Western印迹法检测甲硫腺苷磷酸化酶蛋白质的表达情况; 同时采用高效液相色谱法测定卵巢癌组织中鸟氨酸脱羧酶的活性。20例正常卵巢组织为对照。结果：卵巢癌中MTAP mRNA的表达水平为0.42±0.11,低于正常卵巢的表达水平0.81±0.18,卵巢癌中MTAP mRNA的表达缺失率为15％ (9/60)。 MTAP蛋白表达结果与mRNA基本一致。 MTAP mRNA的表达与卵巢癌病理类型、肿瘤分期、组织分级无明显相关性(P>0.05)。卵巢癌组织中鸟氨酸脱羧酶ODC的活性为(3.82±1.03) U,比正常卵巢组织中ODC的活性(1.38±0.59)U高(P<0.01)。ODC的活性与卵巢癌组织分级呈正相关。9例MTAP表达阴性的卵巢癌ODC活性为(4.83±1.27) U,显著高于MTAP表达阳性的卵巢癌患者(P<0.05)。结论：卵巢癌存在MTAP基因表达减弱或缺失。MTAP基因表达缺失导致ODC的活化可能是卵巢癌的发病机制之一。

Expressions of methylthioadenosine phosphorylase gene and ornithine decarboxylase in ovarian cancer

AIM: To investigate the expressions of methylthioadenosine phosphorylase (MTAP) and ornithine decarboxylase (ODC) in human ovarian cancer. METHODS: 60 fresh samples of ovarian cancer were collected.The expressions of MTAP mRNA and protein were analyzed by using RT-PCR and Western blotting,respectively.ODC activity was measured by high performance liquid chromatography. RESULTS: The expression levels of MTAP mRNA and protein in ovarian cancer were lower than those of control.In 9 of the 60 samples (15%) there were absence of detectable MTAP mRNA and protein.No significant relevance was found between the expression of MTAP and clinical pathologic features.ODC activity in ovarian cancer was (3.82±1.03) U,which was higher than that of normal ovarian tissues (1.38±0.59) U.ODC activity was related with tumor grade.In MTAP-deficiency ovarian cancer tissues ODC activity was significantly increased when compared with that of MTAP-expressing ovarian cancer samples. CONCLUSION: Down-regulated MTAP expression and up-regulated ODC activity really exist in ovarian cancer.Activation of ODC resulting from MTAP deletion may be one of the pathogenetic factors of ovarian cancer.