肝癌组织、外周血细胞磷脂酰肌醇蛋白聚糖3 mRNA表达的意义

Significance of glypican-3 mRNA expression in hepatocellular carcinoma tissues and peripheral blood cells

目的探讨磷脂酰肌醇蛋白聚糖3(GPC3)mRNA表达对肝细胞肝癌(HCC)及其血液微转移的诊断价值。方法参照甲胎蛋白(AFP)mRNA,半定量与巢式逆转录聚合酶链反应(RT-PCR)检测41例HCC、41例癌旁组织、52例非瘤肝组织(41例远离癌灶组织与11例正常肝组织)及67例外周血的GPC3表达。结果半定量PCR显示组织与外周血细胞全部存在GPC3 mRNA表达,HCC、癌旁、非瘤肝组织的表达量分别为78.9±35.5、30.6±21.6、23.8±15.5;而AFP mRNA的表达量依次为61.2±32.6、31.5±23.6、21.2±15.9。各基因在HCC与其他组织中的表达量差异具有统计学意义(P<0.01),以各基因在非瘤肝的相对表达量上限(x-+1.96s)为界,HCC中GPC3 mRNA和AFP mRNA的高表达分别占80.5%与63.4%;至少一个基因高表达HCC达总数的92.7%,与AFPmRNA单独检测差异有统计学意义(P<0.01)。临床病理特征分析发现AFP mRNA与HCC分级及血清AFP浓度有关,GPC3 mRNA表达与HCC分级及侵袭性有关。67例外周血GPC3 mRNA的表达量为15.9±9.0,各类组织中GPC3 mRNA表达均强于相应的外周血表达(P<0.01)。外周血GPC3mRNA表达量在HCC组、非HCC组分别为16.1±8.3、15.6±10.2,组间差异无统计学意义;在HCC转移组、HCC无转移组的表达量各为16.0±9.0、16.3±7.7,组间差异无统计学意义。巢式PCR显示,AFP mRNA表达比率在HCC组与非HCC组各为56.1%、23.1%,组间差异有统计学意义(P=0.011);HCC转移组与无明显转移组各为80.9%、30.0%,组间差异有统计学意义(P=0.002)。结论GPC3 mRNA是潜在的HCC组织诊断指标,与AFP mRNA有明显的互补作用,两者联合检测可提高HCC的阳性检出率;外周血存在GPC3 mRNA的广泛表达,但其与HCC的转移复发无关,不能用于HCC微转移的检测。

Objective To investigate the expressions of glypican-3 （GPC3） mRNA in hepatocellular carcinoma （HCC） tissues and peripheral blood cells （PBCs） , and to determine the values of GPC3 mRNA in the diagnosis of HCC and HCC micrometastasis. Methods Using semi-quantitative and nested reverse transcription polymerase chain reactions （RT-PCR） , we detected the expressions of AFP and GPC3 genes in the tissues of 41 HCC, 4t paracancer and 52 non-HCC liver samples （41 far from HCC tissues and 11 normal liver tissues） , and in the PBCs of 67 specimens from subjects. Results The semiquantitative RT-PCR displayed GPC3 mRNA was expressed in all samples of tissues and PBCs, and the relative intensities of its expressions in HCC, paracancer, non-HCC liver tissues were 78. 9± 35.5, 30. 6 ±21.6, 23.8 ± 15.5 respectively. The AFP mRNA expression values were 61.2 ± 32. 6, 31.5± 23.6, and 21.2 ± 15.9 respectively. The expression of each gene in HCC differed significantly from those in other two kinds of tissue samples （ P 〈 0. 01 ）. The expressions of GPC3 mRNA and AFP mRNA, accounting for 80. 5% and 63.4% in all the HCC tissues, were higher than their respective peak values in the tissues of non-HCC liver （x ＋ 1.96s） , but the expressions of at least one of the two genes was elevated in 92. 7% of all the HCC tissues. There was a significant difference between combined detection of two genes and single AFP mRNA detection in HCC tissues （P 〈0. O1 ）. Clinicopathologically, AFP mRNA was related with the grade of HCC and serum AFP, while GPC3 mRNA was related with not only the grade of HCC but also the invasion of HCC. The relative intensities of GPC3 mRNA expressions in PBCs of 67 specimens was 15.9 ± 9. 0, and GPC3 mRNA expressed in three kinds of tissue samples were all stronger than its counterparts in PBCs （P 〈0. 01 ）. The GPC3 mRNA expression values in PBCs of the HCC group and the non-HCC group were respectively 16. 1± 8. 3, 15. 6 ±10. 2, there was no significant difference between the two groups. Of the HCC metastasis group and the HCC non-metastasis group, the respective GPC3 mRNA expression values in PBCs were 16. 0±9. 0 and 16. 3±7.7, there was also no significant difference between the two groups. The nested RT-PCR showed that the positive rates of AFP mRNA expressions in PBCs from the HCC group and the non-HCC group were 56. 1% and 23.1% ,and the difference between the two groups was significant （P =0. 011 ）. The positive rates of AFP mRNA expressions in PBCs from the HCC metastasis group and the HCC non-metastasis group were 80.9% and 30. 0% ,and there was also a significant difference between the two groups （P = 0. 002）. Conclusions Although GPC3 mRNA is expressed broadly, it still may serve as a potential tissue biomarker in the diagnosis of HCC. Detecting the expression of the two genes in the tissues will improve the screening and diagnosis of HCC. GPC3 is prevalently transcribed in the PBCs, but we have not found any relationship between the GPC3 expression in PBCs and the metastasis or recurrence of hepatoeellular carcinoma, thus we can not identify HCC micrometastasis with GPC3 mRNA.