摘要目的:分析Ly6/Plaur结构域包含蛋白1(LYPD1)在肝癌(HCC)组织中的表达并探讨LYPD1作为肝癌预测因子的潜在可能性，微小RNA(miRNA) MTCO3P38-LYPD1通路作为肝癌治疗靶标的可行性。方法:分析在癌症基因组图谱(TCGA)数据库中下载的419例肝组织(其中肝癌组织369例，正常肝组织50例，配对肝癌组织50对)中LYPD1表达差异，使用GraphPad Prism 8软件计算以LYPD1表达量为肝癌诊断预测模型的ROC曲线下面积。设计对照组和miRNA MTCO3P38组，分别采用脂质体转染对照miRNA和miRNA MTCO3P38至Huh7和HCCLM9肝癌细胞，转染24~48 h后，荧光定量聚合酶链反应(qPCR)检测LYPD1 mRNA表达；蛋白质印迹法(Western blot)检测LYPD1蛋白水平的表达；细胞计数试剂盒(CCK-8)分析两组细胞增殖能力；划痕实验分析两组细胞的迁移能力。组间计量数据比较采用配对样本 t检验或非配对样本 t检验。 结果:LYPD1表达值在369例肝癌组织中高于50例正常肝组织，差异有统计学意义(1.233±0.065比0.148±0.033， t＝6.082， P<0.01)；LYPD1表达值在50例配对肝癌组织中高于50例正常肝组织，差异有统计学意义(1.434±0.222比0.148±0.033， t＝5.734， P<0.01)。以肝癌组织和正常肝组织中LYPD1表达值作为模型预测肝癌诊断，ROC曲线下面积为0.871±0.022[95%可信区间( CI)＝0.828~0.914， P<0.01]。qPCR结果显示LYPD1 mRNA表达值在miRNA MTCO3P38组低于对照组，差异有统计学意义(0.263±0.018比1.033±0.088， t＝7.375， P<0.05)；Western blot结果显示miRNA MTCO3P38组的LYPD1蛋白表达低于对照组，差异有统计学意义(0.800±0.029比2.167±0.088， t＝13.480， P<0.01)；CCK-8实验结果显示miRNA MTCO3P38组细胞活性低于对照组，差异有统计学意义(1.530±0.135比3.553±0.128， t＝7.695， P<0.05)；划痕实验结果显示miRNA MTCO3P38组细胞迁移率低于对照组，差异有统计学意义(5.400±0.057比9.167±0.375， t＝11.850， P<0.01)。 结论:miRNA MTCO3P38下调肝癌潜在诊断预测因子LYPD1的表达抑制肝癌细胞系的细胞增殖和迁移行为。

abstractsObjective:To analyze the expression of Ly6/Plaur domain containing protein 1 (LYPD1) in liver cancer tissues, and explore the feasibility of LYPD1 as a predictive factor for liver cancer and microRNA (miRNA)-MTCO3P38-LYPD1 pathway as a therapeutic target for liver cancer.Methods:The differential expression of LYPD1 in 419 liver tissues downloaded from the cancer genome atlas (TCGA) database (including 369 cases of liver cancer tissues, 50 cases of normal liver tissues, and 50 cases of paired liver cancer tissues) was analysed, and GraphPad Prism 8 software was used to calculate the area under the ROC curve using LYPD1 expression level as the predictive model for liver cancer diagnosis. Control group and miRNA MTCO3P38 group were set up, and control miRNA and miRNA MTCO3P38 were transfected into Huh7 and HCCLM9 liver cancer cells using liposomes, respectively. After 24-48 h of transfection, fluorescence quantitative polymerase chain reaction (qPCR) was used to detect LYPD1 mRNA expression. Western blotting was used to detect the expression level of LYPD1 protein. The cell counting kit-8 (CCK-8) assay was used to analyze the proliferation ability of two groups of cells. The scratch experiment was used to analyze the migration ability of two groups of cells. The comparison of inter group measurement data was conducted using paired sample t-test or non paired sample . Results:The expression value of LYPD1 was significantly higher in 369 cases of liver cancer tissues than in 50 cases of normal liver tissues (1.233±0.065 vs. 0.148±0.033, t=6.082, P<0.01). The expression value of LYPD1 was significantly higher in 50 cases of paired liver cancer tissues than in 50 cases of normal liver tissues (1.434±0.222 vs. 0.148±0.033, t=5.734, P<0.01). Using the expression values of LYPD1 in liver cancer tissue and normal liver tissue as models to predict liver cancer diagnosis, the area under the ROC curve was 0.871±0.022 [95% confidence interval ( CI)=0.828-0.914, P<0.01]. The qPCR results showed that the expression value of LYPD1 mRNA in the miRNA MTCO3P38 group was significantly lower than that in the control group (0.263±0.018 vs. 1.033±0.088, t=7.375, P<0.05). The Western blotting results showed that the expression of LYPD1 protein in the miRNA MTCO3P38 group was significantly lower than that in the control group (0.800±0.029 vs. 2.167±0.088, t=13.480, P<0.01). The CCK-8 experimental results showed that the expression of LYPD1 protein in the miRNA MTCO3P38 group was lower than that in the control group. The cell viability in the miRNA MTCO3P38 group was significantly lower than that in the control group (1.530±0.135 vs. 3.553±0.128, t=7.695, P<0.05). The scratch test results showed that the cell migration rate in the miRNA MTCO3P38 group was significantly lower than that in the control group (5.400±0.057 vs. 9.167±0.375, t=11.850, P<0.01). Conclusion:The downregulation of the expression of LYPD1, a potential diagnostic predictor for liver cancer, by miRNA MTCO3P38 inhibits the cell proliferation and migration behavior of liver cancer cell lines.