肿瘤-睾丸抗原SPANX-C基因mRNA在肝细胞癌中的表达及HLA-A2限制性CTL表位的预测

Expression of cancer-testis antigen SPANX-C mRNA in human hepatocellular carcinoma and prediction of HLA-A2-restricted CTL epitopes of SPANX-C

目的:检测肿瘤-睾丸抗原SPANX-C基因在肝细胞癌(HCC)中的表达,预测SPANX-C/HLA-A2限制性CTL表位.为HCC的免疫治疗寻找新的靶位.方法:用逆转录聚合酶链反应(RT-PCR)方法对HCC患者癌组织、相应癌旁组织和对照组织(肝硬化和正常肝组织)中的SPANX-C基因mRNA进行检测,随机选取RT-PCR阳性扩增产物进行序列测定;用超基序法和量化基序法联合预测SPANX-C/HLA-A2限制性CTL表位.结果:在所检测的115例HCC组织中有70例(60.9%)表达SPANX-C基因mRNA,癌旁组织和20例对照肝组织均不表达.SPANX-C基因的表达与肿瘤分期、肿瘤分化程度、血清甲胎蛋白(AFP)水平等临床指标无相关性(P>0.05).用基序预测法筛选出5个HLA-A2限制性CTL表位(9肽),其中SPANX-C51-59(LVVRYRRNV)与HLA-A2分子具有较高结合力.结论:SPANX-C基因mRNA在HCC组织中呈高频率特异性表达,并存在HLA-A2限制性CTL表位,有望用于HCC的免疫治疗.

AIM：To investigate the expression of SPANX-C （sperm protein associated with the nucleus mapped to the X chromosome-C） gene in hepatocellular carcinoma （HCC） and to predict the HLA-A2-restricted cytotoxic T lymphocyte （CTL） epitopes of SPANX-C to find new targets for specific immunotherapy of HCC.METHODS：The expression of SPANX-C mRNA was characterized by RT-PCR in tumor tissueand adjacent liver tissue specimens from 115 HCC patients and liver tissue specimens from 20 non-HCC patients （10 with liver cirrhosis and 10 without liver disease）.The positive PCR products （297 bp） obtained from 5 tumor tissue specimens were randomly selected for sequencing to confirm the detecting results.HLA-A2-restricted CTL epitopes of SPANX-C were predicted by peptide supermotif prediction method in combination with quantitative motif method.RESULTS：Seventy （60.9%） of 115 tumor tissue specimen from HCC patients expressed SPANX-C mRNA.In contrast,SPANX-C mRNA was not detected in tumor-adjacent tissue and liver tissue from non-HCC patients.There was no discernable correlation between SPANX-C expression and tumor stage,differentiation degree or serum α-fetoprotein level （all P 0.05）.Five CTL epitope candidates （nonamers） derived from the antigen SPANX-C were found by peptide supermotif prediction,of them,SPANX-C51-59 （LVVRYRRNV） may have stronger binding potential with HLA-A2 molecule.CONCLUSION：SPANX-C mRNA is highly expressed in HCC tumor tissue in Chinese patients.SPANX-C may provide potential HLAA2-restricted CTL epitopes as specific targets for immunotherapy of HCC.