Wu Wei, Yao Deng-Fu, Yuan Yong-Mei, Fan Ji-Wei, Lu Xiu-Feng, Li Xiao-Hua, Qiu Li-Wei, Zong Lei, Wu Xin-Hua
Research Center of Clinical Molecular Biology, Affiliated Hospital of Nantong University, Nantong 226001, China.
Hepatobiliary Pancreat Dis Int. 2006 Nov;5(4):538-44.
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, its prognosis is poor, and early detection is of utmost importance. Although alpha-fetoprotein (AFP) is a useful marker for detecting and monitoring HCC development, the false-negative or false-positive rates with AFP alone may be as high as 30%-40% for patients with small HCCs. To enhance the specificity and accuracy of AFP measurements for HCC, we analyzed AFP expression states in livers, detected the hepatoma-specific AFP (HS-AFP) fraction and AFP-mRNA from peripheral blood mononuclear cells, and explored their clinical implications for HCC diagnosis.
AFP expression and hepatocyte distributions in liver specimens were investigated by an immunohistochemical assay. Total RNAs were extracted from circulating blood, synthesized to cDNA through random primers and reverse transcriptase, and fragments of the AFP gene were amplified by a nested-PCR assay. The HS-AFP fraction was separated by lectin-affinity chromatography and its level was detected by radioimmunoassay.
The incidence of AFP was 73.3% in HCC tissues and its expression in HCCs with moderate or low differentiation was significantly stronger than that of HCCs with high differentiation (P<0.05). The incidence of AFP gene fragments was 100% in HCCs, and 60% in paracancerous tissues (P<0.01). In the HCC and liver cirrhosis groups, the incidence of HS-AFP was 91.7% and 18% (P<0.01), and of AFP-mRNA was 56.7% and 16% (P<0.01), respectively, and neither was found in controls. HS-AFP or AFP-mRNA was not significantly related to size or number of HCC, but to its differentiation, metastasis, and relapse (P<0.05).
Different AFP expression is present in different parts of HCC tissues. HS-AFP and AFP-mRNA fragments improve sensitivity and specificity, and both are useful markers to diagnose HCC or monitor metastasis and relapse.
肝细胞癌（HCC）是全球最常见的恶性肿瘤之一，其预后较差，早期检测至关重要。虽然甲胎蛋白（AFP）是检测和监测HCC进展的有用标志物，但对于小肝癌患者，仅AFP的假阴性或假阳性率可能高达30%-40%。为提高AFP检测HCC的特异性和准确性，我们分析了肝脏中AFP的表达状态，检测了肝癌特异性AFP（HS-AFP）组分以及外周血单个核细胞中的AFP-mRNA，并探讨了它们对HCC诊断的临床意义。
采用免疫组织化学法研究肝脏标本中AFP的表达及肝细胞分布。从循环血液中提取总RNA，通过随机引物和逆转录酶合成cDNA，采用巢式聚合酶链反应（PCR）法扩增AFP基因片段。用凝集素亲和层析法分离HS-AFP组分，并用放射免疫法检测其水平。
HCC组织中AFP的发生率为73.3%，中低分化HCC中AFP的表达明显强于高分化HCC（P<0.05）。HCC中AFP基因片段的发生率为100%，癌旁组织中为60%（P<0.01）。在HCC组和肝硬化组中，HS-AFP的发生率分别为91.7%和18%（P<0.01），AFP-mRNA的发生率分别为56.7%和16%（P<0.01），对照组均未发现。HS-AFP或AFP-mRNA与HCC的大小或数量无明显相关性，但与HCC的分化、转移及复发有关（P<0.05）。
HCC组织不同部位存在不同的AFP表达。HS-AFP和AFP-mRNA片段提高了敏感性和特异性，二者都是诊断HCC或监测转移及复发的有用标志物。
