肝细胞生长因子及其受体c-met在肝细胞癌中的表达与预后价值

Study on the prognostic value of hepatocyte growth factor and c-met for patients with hepatocellular carcinoma

目的研究肝癌切除前、后血清肝细胞生长因子(HGF)的动态变化及其受体c met在癌组织中的表达,探讨HGF/c met对手术切除后肝癌患者的预后价值。方法收集手术切除的25例肝细胞癌患者血清及组织标本,用酶联免疫法(ELISA)测定术前1d、术后第3、7、10天血清HGF浓度,分别用免疫组织化学及逆转录聚合酶链反应(RT PCR)方法检测肝癌及癌旁组织中c met蛋白及mRNA的表达。分析术前血清HGF水平及癌组织中c met表达程度与不同临床病理因素之间的关系及影响手术后血清HGF水平变化的因素。以20例健康献血员为正常对照组,22例慢性乙型肝炎患者及22例乙型肝炎肝硬化肝功能失代偿(ChildB或C级)患者作为慢性乙肝组和肝硬化失代偿组。结果肝癌患者血清HGF浓度高于正常对照组及慢性乙肝组[(1.03±0.09)ng/ml比(0.69±0.02)、(0.74±0.09)ng/ml,P<0.05],但与肝硬化失代偿组[(1.04±0.11)ng/ml]比较差异无统计学意义。术后HGF浓度上升高峰出现在术后第3天,术后第7、10天逐渐下降,但仍高于正常水平。术前、术后各组的血清HGF组间比较,仅术后第3天组差异有统计学意义。影响术前血清HGF水平的主要因素有:肿瘤直径>5cm、伴有结节肝硬化、门静脉癌栓、术前血清甲胎蛋白(AFP)≥400μg/L。从术前到术后第3天,大区段切除比小区段切除者的血清HGF浓度上升更明显(P=0.047)。中度和强阳性c met蛋白表达在肝癌组织中(21/25)明显高于癌旁组织(5/25)。高表达的c metmRNA见于所有肝癌组织中,在癌旁组织中仅6例有高表达。癌组织中c met蛋白表达的强度与有无合并门静脉癌栓有关,与肿瘤大小、血清AFP水平、血清HGF水平、有无肝硬化及肝癌的分化程度无相关性。但在癌旁组织,合并肝硬化组c met蛋白表达高于无肝硬化组。术后有肿瘤复发或转移的病例,其术前血清HGF水平及肿瘤组织中c met蛋白表达显著高于无复发或转移的病例。HGF水平与肿瘤组织中c met表达无相关性。结论肝癌患者有血清HGF及癌组织中c met的高表达,术后血清HGF的持续升高可能与肝癌的早期复发和转移有关。

Objective To analyze the prognostic value of hepatocyte growth factor （HGF） and c-met for patients with hepatocellular carcinoma （HCC） after hepatectomy. Methods Twenty-five patients undergoing partial hepatectomy for HCC were studied. Serum HGF level was determined using ELISA kit before and after operation respectively, c-met protein and mRNA expression in cancerous and paracancerous tissues were detected by immunohistochemical and RT-PCR methods respectively. The correlations of clinical- pathologic parameters with the HGF level in serum and c-met expression in cancerous tissue were analyzed respectively. Results HCC patients had a significantly higher concentration of serum HGF than normal controls and chronic hepatitis B respectively [ （ 1.03 ± 0. 09 ） ng/ml vs （ 0. 69 ±0. 02 ） ng/ml and （0. 74±0. 09）ng/ml]. No significant difference in serum HGF was observed between HCC and cirrhosis patients with Child-Pugh score B/C [ （ 1.03±0. 09 ） ng/ml vs （ 1.04 ±0. 11 ） ng/ml ]. Serum HGF concentrations were positively correlated with tumor size （ 〉 5 cm）, node cirrhosis, portal vein tumor thrombi （PVTT） and preoperative α-fetoprotein （AFP） level（ ≥400μg/L）. After the resection of tumor, serum HGF concentration had a peak on the third postoperative day （POD）, and then declined, but did not return to normal level on the tenth POD. From preoperative day to third POD, HGF concentration had a higher elevation in patients with major resection than with local resection. Moderately or strongly positive expression of c-met protein was observed in 21 cancerous regions （21/25）, and only in 5 paracancerous regions. The intensive expression of c-met mRNA was 100% （25/25） detectable in the cancerous tissues, but only 24% （6/25） in the paracancerous tissues. The expression extent of c-met protein was correlated with portal vein tumor thrombi （PVTI＇）. In paracancerous tissues, the expression of c-met protein was more intense in patients with cirrhosis than those without cirrhosis. The patients with recurrence or metastases after operation had a higher level of serum HGF and more intensive expression of c-met than other patients. No significant association was observed between HGF in serum and c-met expression in cancerous tissue. Conclusions The over-expression of HGF and its receptor c-met indicate an adverse prognosis for HCC patients. The sustained high level of serum HGF after hepatectomy may be a factor related to early tumor recurrence and metastasis.