【摘要】 目的探讨MHCⅠ类链相关蛋白A(MHC classⅠchain-related A,MICA)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)在骨肉瘤组织学和血清学中的关系,为研究骨肉瘤组织中MICA蛋白脱落的分子机制提供组织学基础。方法应用免疫组织化学方法检测16例骨肉瘤中MICA和MMP-9蛋白的表达情况,同时采用酶联免疫吸附实验(enzyme-linked immunosorbent assay,ELISA)检测16例骨肉瘤患者血清中MICA和MMP-9的含量。结果16例骨肉瘤组织中MICA和MMP-9蛋白的表达率分别为42.5%(7/16)和56.3%(9/16),两者的表达无相关性(r=0.454,P>0.05);骨肉瘤患者血清中可溶性MICA(soluble MICA,sMICA)浓度高于健康人(P<0.05),与血清中MMP-9的浓度无相关性(r=-0.429,P>0.05),但与组织中MICA蛋白表达呈负相关(r= -0.502,P<0.05)。结论骨肉瘤患者血清中sMICA浓度升高,而血清中MMP-9含量对MICA浓度无明显影响;骨肉瘤患者可能存在NKG2D-MICA介导的免疫监视功能障碍,MICA蛋白的脱落可能是骨肉瘤逃避免疫监视的一个新机制。更多还原

【Abstract】 Objective To investigate the mechanism of the shedding of MHC class I chain-related A(MICA) in osteosarcoma;and the relationship between MICA and matrix metalloproteinase-9(MMP-9) in osteosarcoma tissues and patient’s sera was studied.Methods MICA and MMP-9 expression was examined in 16 osteosarcoma tissues by immunohistochemistry. Meanwhile,serum level of soluble MICA(sMICA) and MMP-9 in 16 osteosarcoma patients was evaluated by ELISA.Results MICA and MMP-9 protein were detected in 42.5%(7/16) and 56.3%(9/16) of osteosarcoma tissues,respectively.MICA expression was not correlated with MMP-9 expression(r=0.454,P>0.05). Serum level of sMICA in osteosarcoma patients was higher than the healthy(P<0.05),but it was negatively correlated with MICA expression in osteosarcoma tissues(r=-0.502,P<0.05).No correlation was found between sMICA and MMP-9 in patient’s sera(r=-0.429,P>0.05).Conclusion Higher serum level of sMICA can be detected in osteosarcoma tissues and can not be affected by the content of MMP-9 in sera,osteosarcoma patients might have a deficiency of MICA-NKG2D mediated immunosurveillance.The shedding of MICA protein might be a new mechanism of immune evasion for osteosarcoma.更多还原