The Profiling of Cholangiocarcinoma and the Development of Molecular targeted therapy

胆管癌是东南亚国家最常见的肝脏肿瘤之一，是来源于胆管上皮的原发性恶性肿瘤。尽管综合治疗取得了一定的进展，但其预后仍是所有恶性肿瘤中最差的。为了寻找治疗胆管癌的分子靶点，我们使用包含1176个独特基因的cDNA表达阵列比较了胆管癌和正常肝脏的基因表达模式。在这些探索的基因中，我们将Nek 2鉴定为以肿瘤特异性方式显示高表达的候选基因。我们研究了丝氨酸/苏氨酸激酶家族Nek的成员Nek 2在胆管癌细胞致瘤性生长中的作用。与正常成纤维细胞相比，Nek 2的表达在胆管癌中以肿瘤特异性方式升高。虽然外源性Nek 2的表达不干扰胆管癌细胞的生长，但用siRNA抑制Nek 2的表达导致细胞增殖抑制和诱导细胞死亡。在裸鼠移植瘤模型中，皮下注射Nek 2 siRNA可使肿瘤体积缩小。在腹膜播散模型中，Nek 2 siRNA处理的小鼠与对照siRNA处理的小鼠相比显示出统计学上更长的存活期。总之，这是首次证明Nek 2在胆管癌的致瘤性生长中起关键作用，并且用其siRNA抑制Nek 2表达导致胆管癌生长和存活的抑制。我们的体内数据为进一步研究Nek 2抑制剂作为一种新的癌症治疗提供了强有力的理论基础，具有提供多种人类恶性肿瘤消退的潜力。

Cholangiocarcinoma, one of the most common liver tumors in South-east Asian countries, is a primary malignancy derived from the bile duct epithelium. Despite the progress of the combined therapy, its prognosis is still extremely miserable among all malignancies. To search for the molecular targets for the treatment of cholangiocarcinoma, we compared the gene expression pattern of cholangiocarcinoma with those of a normal liver using cDNA expression array containing 1176 unique genes. Among these explored genes, we identified Nek2 as a candidate that showed high expression in a tumor-specific manner. We investigated the role of Nek2, a member of the serine/threonine kinase family, Nek, in the tumorigenic growth of cholangiocarcinoma cells. Expression of Nek2 is elevated in cholangiocarcinoma in a tumor-specific manner as compared with that of normal fibroblast cells. While expression of exogenous Nek2 did not perturb the growth of cholangiocarcinoma cells, suppression of the Nek2 expression with siRNA resulted in the inhibition of cell proliferation and induced cell death. In xenograft-nude mouse model, subcutaneous injection of Nek2 siRNA around the tumor nodules resulted in reduction of tumor size as compared with those of control siRNA injection. In peritoneal dissemination model, Nek2 siRNA-treated mice showed statistically longer survival periods in comparison with those of the control siRNA-treated mice. In summary, this is the first demonstration that Nek2 plays a critical role in tumorigenic growth of cholangiocarcinoma, and inhibition of Nek2 expression with its siRNA causes suppression of cholangiocarcinoma growth and survival. Our data in vivo provides a strong rationale for the further investigation of Nek2 inhibitors as a new cancer therapy, holding the potential to provide regression of multiple human malignancies.