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目的:探讨黑素瘤抗原MAGE-A9和MAGE-A11在乳腺正常组织、乳腺良性病变、乳腺癌组织中的表达以及甲基化酶抑制剂5-氮杂-2'-脱氧胞苷(5-Aza-2’-deoxycytidine,5-Aza-CdR)和组蛋白去乙酰化酶抑制剂曲古抑菌素A(TSA)对MAGEA9和MAGE-A11基因表达的影响。方法:应用RT-PCR和免疫组化方法检测60例乳腺正常组织、60例乳腺良性病变及60例乳腺癌组织(标本均取自河北医科大学第四医院乳腺中心2007年11月至2008年5月乳腺手术治疗患者)中MAGE-A9和MAGE-A11 mRNA及其蛋白的表达,分析其与乳腺癌患者临床病理学特征的关系。RT-PCR检测乳腺癌细胞MCF-7、MDA-MB-231经5-Aza-CdR和TSA单独或联合作用后MAGE-A9和MAGE-A11 mRNA表达量的变化。结果:乳腺癌组织中MAGE-A9mRNA和蛋白阳性表达率分别为45%(27/60)和43.3%(26/60),MAGE-A11 mRNA和蛋白阳性表达率分别为66.7%(40/60)和63.3%(38/60),而乳腺正常组织及良性病变组织中均未发现MAGE-A9、MAGE-A11 mRNA及其蛋白的表达。MAGE-A9、MAGE-A11 mRNA和蛋白的表达与乳腺癌患者的年龄、病理类型、临床分期、肿瘤大小、淋巴转移、瘤栓及孕激素受体的表达均无明显关系(P>0.05),但与人表皮生长因子受体2(HER-2)和雌激素受体(ER)的表达有关(P<0.05)。未经药物处理的MCF-7、MDA-MB-231细胞未见MAGE-A9和MAGE-A11 mRNA表达;单用5-Aza-CdR处理后可见MAGE-A9和MAGE-A11基因重新表达,联合应用5-Aza-CdR和TSA处理可使MAGE-A9、MAGE-A11基因的表达量进一步增加(P<0.05);而TSA单独处理对基因表达没有影响(P>0.05)。结论:乳腺癌组织中MAGE-A9和MAGE-A11的表达与ER和HER-2的表达有关,5-AzaCdR单用或联合应用TSA可诱导和增强MAGE-A9和MAGE-A11 mRNA的重新表达,说明DNA的去甲基化和组蛋白乙酰化可能是调控人类肿瘤细胞MAGE表达的重要机制。
AIM: To investigate the expression of melanoma antigens MAGE-A9 and MAGE-A11 in normal breast tissues, benign breast lesions and breast cancer tissues and to explore the role of methylation inhibitor 5-aza-2'-deoxycytidine (5- Aza-2'-deoxycytidine, 5-Aza-CdR and histone deacetylase inhibitor trichostatin A (TSA) on the expression of MAGEA9 and MAGE-A11 genes. Methods: Sixty cases of breast normal tissue, 60 cases of benign breast lesions and 60 cases of breast cancer tissues were detected by RT-PCR and immunohistochemistry (specimens were collected from the Breast Center of the Fourth Hospital of Hebei Medical University from November 2007 to May 2008 MAGE-A11 and MAGE-A11 mRNA and protein expression in patients with breast cancer who underwent surgery on breast cancer. The relationship between the expression of MAGE-A9 and MAGE-A11 mRNA and its protein and the clinicopathological features of breast cancer patients was analyzed. The changes of MAGE-A9 and MAGE-A11 mRNA expression in MCF-7 and MDA-MB-231 breast cancer cells treated with 5-Aza-CdR and TSA alone or in combination were detected by RT-PCR. Results: The positive rates of MAGE-A9 mRNA and protein in breast cancer tissues were 45% (27/60) and 43.3% (26/60), respectively. The positive rates of MAGE-A11 mRNA and protein were 66.7% (40/60) And 63.3% (38/60), respectively. However, the expression of MAGE-A9 and MAGE-A11 mRNA and protein in normal breast tissues and benign lesions were not found. The expression of MAGE-A9 and MAGE-A11 mRNA and protein had no significant correlation with age, pathological type, clinical stage, tumor size, lymph node metastasis, tumor suppository and progesterone receptor expression in breast cancer patients (P> 0.05) But related to the expression of human epidermal growth factor receptor 2 (HER-2) and estrogen receptor (ER) (P <0.05). No expression of MAGE-A9 and MAGE-A11 mRNA was detected in MCF-7 and MDA-MB-231 cells without drug treatment. MAGE-A9 and MAGE-A11 genes were re-expressed after treated with 5-Aza-CdR alone The expression of MAGE-A9 and MAGE-A11 gene was further increased by 5-Aza-CdR and TSA treatment (P <0.05), while TSA alone had no effect on gene expression (P> 0.05). Conclusion: The expression of MAGE-A9 and MAGE-A11 in breast cancer tissues is related to the expression of ER and HER-2. 5-AzaCdR alone or in combination with TSA can induce and enhance the re-expression of MAGE-A9 and MAGE- Demethylation of DNA and histone acetylation may be important mechanisms regulating the expression of MAGE in human tumor cells.