Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Hepatobiliary Pancreat Dis Int. 2010 Jun;9(3):296-305.
Hepatocellular carcinoma (HCC) is a highly malignant tumor with a poor prognosis. Because small HCCs possess most of the characteristics of early HCC, we investigated small HCCs to screen potential biomarkers for early diagnosis.
Proteins were extracted from 10 sets of paired tissue samples from HBV-infected small-HCC patients. The extracted proteins were well resolved by two-dimensional electrophoresis. These HCC-associated proteins were then identified by MALDI-TOF/TOF MS following image analysis. Western blotting and immunohistochemistry were used to assess glutamine synthetase (GS) and phenazine biosynthesis-like domain-containing protein (PBLD) expression in liver tissue. Enzyme-linked immunosorbent assays in 152 serum samples (from 49 healthy donors, 24 patients with liver cirrhosis, and 79 with HCC) were used to further assess the significance of GS clinically.
Fifteen up-regulated and three down-regulated proteins were identified. Western blotting confirmed GS overexpression and decreased PBLD expression in liver tissue. Immunohistochemistry showed that GS was expressed in 70.0% (84/120) of HCCs and 35.8% (43/120) of nontumor tissues; PBLD was expressed in 74.2% (89/120) of nontumor tissues and 40.8% (49/120) of HCCs. The Chi-square test showed significant expression differences between HCCs and adjacent tissues. Consistent with this, serum GS levels in HCC patients were significantly higher than those in liver cirrhosis patients and healthy donors, while the latter two groups were also significantly different. In addition, a diagnostic cutoff value of 2.6 mg/ml was used for GS; it was elevated in 19 (76.0%) of 25 HCC patients with AFP <or=20 ng/ml and 47 (88.7%) of 53 HCC patients with AFP <or=200 ng/ml.
GS and PBLD are abnormally expressed in most HCCs. GS may be a novel serum marker for early HCC, especially for those patients with low AFP levels (<or=200 ng/ml).
肝细胞癌（HCC）是一种高度恶性肿瘤，预后不良。由于小 HCC 具有大多数早期 HCC 的特征，我们研究了小 HCC，以筛选用于早期诊断的潜在生物标志物。
从 10 对 HBV 感染的小 HCC 患者的组织样本中提取蛋白质。通过二维电泳很好地分离这些 HCC 相关蛋白，然后通过 MALDI-TOF/TOF MS 进行图像分析鉴定。Western 印迹和免疫组化用于评估肝组织中谷氨酰胺合成酶（GS）和吩嗪生物合成样结构域蛋白（PBLD）的表达。在 152 份血清样本（来自 49 名健康供体、24 名肝硬化患者和 79 名 HCC 患者）中进行酶联免疫吸附试验进一步评估 GS 在临床上的意义。
鉴定出 15 种上调蛋白和 3 种下调蛋白。Western 印迹证实了肝组织中 GS 的过度表达和 PBLD 表达的降低。免疫组化显示，GS 在 70.0%（84/120）的 HCC 和 35.8%（43/120）的非肿瘤组织中表达；PBLD 在 74.2%（89/120）的非肿瘤组织和 40.8%（49/120）的 HCC 中表达。卡方检验显示 HCC 与相邻组织之间的表达差异具有统计学意义。与此一致的是，HCC 患者的血清 GS 水平明显高于肝硬化患者和健康供体，而后两组之间也存在显著差异。此外，将 GS 的诊断截断值设为 2.6mg/ml；在 AFP<or=20ng/ml 的 25 例 HCC 患者中有 19 例（76.0%）和 AFP<or=200ng/ml 的 53 例 HCC 患者中有 47 例（88.7%）升高。
GS 和 PBLD 在大多数 HCC 中表达异常。GS 可能是早期 HCC 的新型血清标志物，特别是对于 AFP 水平较低（<or=200ng/ml）的患者。
