Abstract: Objective To detect the level of TIZ mRNA in ovarian cancer cell lines and to construct the vector of TIZ mRNA interference (RNAi).Methods The expression levels of TIZ mRNA in several ovarian cancer cell lines were detected.The cell lines included SKOV3，SKOV3-cisplatin resistance，SKOV3-carboplatin resistance，A2780，A2780-cisplatin resistance and HO8910.Five pairs of TIZ siRNA were designed according to the sequence of TIZ mRNA in Genebank.The siRNAs were transfected by liposome to down-regulate the expression of TIZ mRNA in ovarian cancer cell lines.TIZ mRNA and β-actin mRNA expression plasmids were construct red by using pTG19-T plasmid，and their standards were prepared.The real-time quantitative polymerase chain reaction (QRT-PCR) was used to detect the efficiency of TIZ siRNA and then to select the best one.The pGPU6/GFP/Neo vector and plasmid DNA sequencing method was used to build pGPU6/GFP/Neo-siRNA-TIZ-573 restructured plasmid.Results TIZ mRNA expressed in all ovarian cancer cells except HO8910.siRNA TIZ-573 down regulated 60% of TIZ mRNA expression.The vector TIZ RNAi pGPU6/GFP/Neo-TIZ-573 was constructed successfully.Conclusions Most ovarian cancer cell lines express TIZ mRNA.siRNA-TIZ-573 is the best segments that can down regulate TIZ mRNA.The recombinanted plasmid GPU6/GFP/Neo-TIZ-573 can be used for the next experiments.

Key words: TIZ gene, Ovarian cancer cells, siRNA