骨肉瘤组织中MICA基因mRNA和蛋白的表达

【目的】 检测骨肉瘤组织中MHC I类链相关蛋白A(MHC class I chain-related A,MICA)基因mRNA和蛋白的表达情况,为探讨骨肉瘤的肿瘤免疫机制提供信息｡ 【方法】 应用RT-PCR方法检测MICA mRNA在11例新鲜骨肉瘤组织和5个骨肉瘤细胞株中的表达情况;分别应用免疫组织化学方法､Western blot和流式细胞术检测66例石蜡包埋骨肉瘤组织､6例石蜡包埋正常人骨组织､9例新鲜骨肉瘤组织和5个骨肉瘤细胞株中MICA蛋白的表达情况｡ 【结果】 骨肉瘤组织中MICA mRNA表达率为81.8%(9/11),5个骨肉瘤细胞株均表达MICA mRNA;MICA蛋白在骨肉瘤组织和正常骨组织的表达率分别为51.6%(34/66)和0%(0/6);骨肉瘤细胞株Saos-2､MG63和HOS阳性表达膜表面MICA蛋白,而细胞株U2OS和OS732只有少量细胞呈阳性表达｡【结论】 MICA mRNA和蛋白广泛表达于骨肉瘤组织和细胞株｡

Expression of MICA mRNA and Protein in Osteosarcoma

[Objective] To investigate the expression of MICA mRNA and protein in osteosarcoma and give a more comprehensive understanding to its immune evasion.[Methods] RT-PCR was used to analyze MICA mRNA in 11 osteosarcoma tissues and 5 osteosarcoma cell lines.MICA expression was examined in 66 paraffin-embedded osteosarcoma tissues and 6 paraffin-embedded normal bone tissues by immunohistochemistry,and MICA protein in 9 fresh osteosarcoma tissues was detected by Western blot too.MICA surface expression was estimated by flow cytometry.[Results] Nine of eleven (81.8%) osteosarcoma specimens and all of the five cell lines consistently expressed MICA mRNA.Up-regulation of MICA expression was found in osteosarcoma (34/66,51.6%),compared with normal bone tissues (0/6,0%).The cell lines Saos-2,MG63,and HOS showed positive surface MICA expression,while the U2OS and OS732 showed very limited expression.[Conclusion] MICA mRNA and protein predominantly expressed on osteosarcoma tissues and cell lines.