一氧化氮合酶在原发性肝癌及癌旁肝硬化组织中的表达及其意义

Expression of nitric oxide synthase in human hepatocellular carcinoma and cirrhotic liver tissue and its clinical significance

目的探讨一氧化氮合酶在原发性肝癌及癌旁肝硬化组织中的表达及意义。方法采用ＮＡＤＰＨ黄递酶（ＮＡＤＰＨ－ｄ）组织化学染色及Ｎｏｒｔｈｅｍ印迹杂交技术，检测了２３例肝癌及２２例癌旁肝硬化组织中诱导型一氧化氮合酶（ｉＮｏｓ）的分布和表达状况。结果肝癌组织和肝硬化组织均呈现ｉＮｏｓ染色阳性，其中肝硬化组织ｉＮｏｓ表达强度明显高于肝癌组织。正常肝组织中则无ｉＮｏｓ表达。在肝癌组织中，ｉＮｏｓ主要分布在肝癌细胞的细胞质内，浸润的淋巴细胞呈阴性表达。ｉＮｏｓ表达与肝癌瘤体大小、肿瘤病理分型、血清ＡＦＰ水平均无明显关系。结论ｉＮｏｓ在肝硬化组织中持续高表达，其强烈的细胞毒性作用可能会造成肝细胞损伤，继而成为癌变的诱因。

Objective To explore the expression, distribution and clinical significance of nitric oxide synthase (iNOS) in hepatocellular carcinoma and pericarcinomatous cirrhotic tissue. Method The NADPH diaphorase histochemistry and Northern blot technique were used to localize the activity of iNOS in 23 HCC and 22pericarcinomatous cirrhotic tissue samples. Result When tested, postive expression of iNOS was shown in bothHCC and cirrhotic tissues. iNOS activity in cirrhotic hepatocytes was stronger than that in tumor cells. There wasno positive iNOS staining in normal hepatocytes, wile in cirrhotic tissue most hepatocytes were postively stained.In tumor tissue, iNOS distributed in HCC cells but not in tumor-infiltrating lymphocytes (TIL). The intensity of iNOS expression was not related to tumor size, pathologic type, and level of serum AFP. Conclusion Sustainedhigh level expression of iNOS in cirrhotic tissue does not only cause reduced ability of liver regeneration, but mayalso increase the risk of liver cancer transformation.