Identification of transcription factor Sp-1 up-regulating the expression of CD59 in prostate cancer.

Objective: To construct recombinant vectors expressing siRNA that target Sp1 gene and a stable-inhibit cell line PC-3 in order to analyze the role of Sp1 in the expression of CD59. Methods: The 63 bp encoded targeting Sp1 gene shRNA sequence was cloned and transferred into pSUPER vector by DNA recombinant technique. The prostate cancer cell PC-3 was transfect with this recombinant plasmid by liposome and the stable strains was selected by G418 medium. Sp1 and CD59 protein was detected by Western blotting, and its function was detected by dye release assay. Results: The pSUPER-siRNA expressing vector was successfully constructed, and a stable cell line PC-3 was selected and detected the expression of GFP. The siRNA vector effectively inhibited the CD59 gene expression from protein in level. MTT assay and Dye release assay suggested that CD59's protection to complement mediated cytolysis decreased. Conclusion: The siRNA vector targeting Sp1 gene could consistently inhibit CD59 expression. Furthermore, it decreased CD59's protection against complement. These results may pave the way for studying the role of Sp1 in the expression of CD59.