The Profiling of Cholangiocarcinoma and the Development of Molecular targeted therapy

胆管癌是一种起源于胆管上皮的原发性恶性肿瘤，是东南亚国家最常见的肝脏肿瘤之一。尽管联合治疗取得了进展，但在所有恶性肿瘤中，其预后仍然非常糟糕。为了寻找治疗胆管癌的分子靶点，我们利用包含1176个独特基因的cDNA表达阵列，比较了胆管癌与正常肝脏的基因表达模式。在这些被探索的基因中，我们发现Nek2是一个候选基因，它以肿瘤特异性的方式表现出高表达。我们研究了丝氨酸/苏氨酸激酶家族成员Nek在胆管癌细胞的致瘤性生长中的作用。与正常成纤维细胞相比，Nek2的表达在胆管癌中以肿瘤特异性的方式升高。虽然外源性Nek2的表达不会干扰胆管癌细胞的生长，但用siRNA抑制Nek2的表达会抑制细胞增殖并诱导细胞死亡。在异种移植裸鼠模型中，在肿瘤结节周围皮下注射Nek2 siRNA，与对照组相比，肿瘤大小减小。在腹膜播散模型中，与对照组相比，Nek2 sirna处理小鼠的生存期更长。综上所述，这是首次证明Nek2在胆管癌的致瘤性生长中起关键作用，通过其siRNA抑制Nek2的表达可抑制胆管癌的生长和存活。我们在体内的数据为进一步研究Nek2抑制剂作为一种新的癌症治疗方法提供了强有力的理论依据，它有可能提供多种人类恶性肿瘤的消退。

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.