隐匿性乙型肝炎病毒感染在隐源性肝癌发生中的作用

The effect of occult HBV infection on carcinogenesis of cryptogenic hepatocellular carcinoma

目的探讨隐匿性乙型肝炎病毒（HBV）感染在隐源性肝癌发生中的作用。方法收集中山大学附属第三医院2011年1月至2013年12月行肝癌切除术的66例患者的肝癌及癌旁组织。其中26例为乙型肝炎病毒表面抗原（HBsAg）阴性的隐源性肝癌（CH组），40例为乙型肝炎相关性肝癌（HH组）。另取30例正常肝组织作为对照。采用巢式PCR方法检测HBVDNA，免疫组织化学方法检测乙型肝炎病毒x蛋白（HBx）及Yes相关蛋白（YAP）表达。结果20例隐源性肝癌患者存在隐匿性HBV感染，占76．9％；正常组为8例，占26．7％，两者差异具有统计学意义（∥=14．072，P〈0．05）。40例乙肝相关性肝癌均可检出HBVDNA。HBx阳性表达主要定位于肝细胞及肝癌细胞的胞质，YAP表达定位于胞核，呈弥漫性棕黄色或棕褐色颗粒。HBx在HH组与CH组癌组织的阳性表达率分别为80．0％和90．0％，在癌旁组织分别为85．0％和82．5％，对照组阳性表达率为40．0％。YAP在HH组与CH组的癌组织阳性表达率分别为65．0％和67．5％，癌旁组织分别为15．0％和20．0％，对照组阳性表达率为12．5％。对阳性细胞进行统计学分析，结果表明HH组与CH组的癌与癌旁组织比较，HBx表达无统计学差异（P〉0．05），YAP在癌组织中的表达阳性率明显高于癌旁组织（P〈0．05）。HH组与CH组比较，HBx及YAP表达差异无统计学意义（P〉0．05）；HBx及YAP在HH组、CH组癌组织中的表达阳性率明显高于正常肝组织（P〈0．05）。结论隐源性肝癌患者有较高的隐匿性HBV感染率，HBx及YAP高表达可能参与了隐源性肝癌的发生。

Objective To investigate the effect of occult HBV infection （OBI） on carcinogenesis of cryptogenic hepatocellular carcinoma. Methods Samples of hepatocellular carcinoma （HCC） and pericar- cinomatous tissues obtained after hepatectomy from January 2011 to November 2013 at the Third Affiliated Hospital of Sun Yat-Sen University were collected. They were divided into two groups ： the cryptogenic HCC group （the CH group, n =26） and the HBV related HCC group （the HH group, n =40）. These samples were compared with the normal liver tissues obtained in 30 patients. HBV DNA was identified by the nested polymerase chain reaction and the immunohistochemical method was taken to examine the hepatitis B virus X protein （HBx） and Yes-associated protein （YAP） expressions. Results OBI was identified in 20 （77.8%） cryptogenic HCC patients and 8 （26.7%） in the control group. There was a significant difference between the two groups （ χ2 = 14. 072, P 〈0. 05 ）. HBV DNA was detected in all the HBV-related HCC pa- tients. The HBx protein expression was mainly located in the cytoplasm of liver cells and liver cancer cells, but YAP was expressed in the nucleus. Both of them showed diffuse brown or tan particles. In the HH group and the CH group, the positive expression rates of HBx protein in the tumorous tissues were 80. 0% and 90. 0%, respectively, and 85.0% and 82.5% in the nontumorous tissues, but only in 40.0% in the control group. The positive expression rates of YAP in the tumorous tissues were 65.0% and 67.5% , respectively, 15.0% and 20.0% in the nontumorous tissues, respectively, but only in 12.5% in the control group. The HBx expression in the cancerous tissues and para-cancerous tissues of the HH group and the CH group showed no significant difference （P 〉0. 05 ）, but the YAP expression in the tumor tissues was significantly higher than that in the nontumorous tissues （ P 〈 0. 05 ）. The HBx and YAP expressions in the HH group were comparable to the CH group （P 〉0. 05 ）. However, their expressions in the cancerous tissue of the HH group and the CH group were significantly higher than in the normal fiver tissues （ P 〈 0. 05 ）. Conclusion A high prevalence of HBV infection was observed in HBsAg-negative HCC and the high expressions of HBx and YAP might be involved in the process of cryptogenic hepatocellular carcinoma.