Construction Of A Series Of RNA Interference Vectors And Their Application In The Study Of Genes Involved In The Invasion And Metastasis Of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world, which results in approximately one million people's death annually. The ratio of the incidence and the death rate of HCC is so high as 1:0.98. The high death rate is mainly due to the strong capability of invasion and metastasis. The invasion and metastasis of HCC include multiple steps in which many factors are involved. This study intended to silence several genes, such as HPO, c-met and MT1-MMP, which play important roles in the invasion and metastasis of HCC, through RNA interference (RNAi). It might contribute a lot to the set-up of the HCC cell model in which the invasion and metastasis were restrained in a large extent and the understanding of the mechanisms of anticancer and gene therapy of HCC both in vitro and in vivo.In the study, we first established a vector based RNAi system. The H1 promoter, one of type â…¢ RNA polymerase â…¢ promoters, is very fit for the construction of RNAi vectors due to the facts that target molecules can be expressed at a high level in the mammalian cells and all of its cis-acting elements locate in the H1 RNA 5'-flanking region. Based on the H1 promoter, four RNAi vector systems, pSL, pESL in which an EGFP gene is inserted, pcDDH and pRDH, were constructed. The pSL and pESL vectors work very well in knocking-down gene expression. For example, we demonstrated that they could decrease the expression level of p53 to 87.66% and the efficiency is much higher than the commercial pSilencer^TM 3.1-H1 hygro RNAi vector (Ambion). Therefore, the data suggested that pSL and pESL RNAi vector systems are new useful tools to investigate gene function in cultured mammalian cells. Both pcDDH and pRDH RNAi vectors, which could express siRNA in vivo and could be used in the...