Construction of RNAi recombinant vector of galectin-1 and establishment of LST-R1 cell lines stably transfected by the recombinant vector / 解放军医学杂志

ABSTRACT

Objective To construct the RNA interference (RNAi) eukaryotic expression vectors of galectin-1, and establish the LST-R1 cell lines stably transfected by RNAi vectors. Methods Two pairs of small interfering RNAs (siRNA) targeting to galectin-1 mRNA (GenBank NM002305) were designed. The corresponding single-strand short hairpin interfering RNAs (shRNA), containing BamH Ⅰ, Hind Ⅲ sites and a 9nt hairpin structure, was synthesized and annealed. The annealed product and the linear eukaryotic expression plasmid pSuperior-puro, which were digested with Bgl Ⅱ and Hind Ⅲ, were ligated by T4 ligase to set up the interfering system. The recombined plasmid was identified with EcoR Ⅰand Hind Ⅲ enzyme digestion and sequencing, and co-transfected to LST-R1 cells with pcDNA6/TR with Lipofectamine2000. Positive clones were selected with 0.8?g/ml puromycin. After incubated with 4?g/ml tetracyclin for 48 hours, RT-PCR, Western blotting and immunochemistry were employed to determine galectin-1 mRNA and protein levels. Results Sequencing results suggested that the nucleotide sequence and read frame of RNAi eukaryotic exprssion vector of galectin-1, p-shRNA1 and p-shRNA2 were perfect. Stably transfected LST-R1 cell lines of p-shRNA1-LST and p-shRNA2-LST were established. The relative values of galectin-1 expression in LST-R1 cells, p-shRNA1-LST cells, p-shRNA2-LST cells and p-LST cells by RT-PCR were 0.616, 0.298, 0.373 and 0.641, respectively, and 1.00, 0.07, 0.38 and 0.97 by Western blotting. The p-shRNA1 gave the best interfering effect, which was in conformity with the results of immunochemistry measurement. Conclusions RNAi eukaryotic expression vector of galectin-1 mRNA has been successfully constructed. Establishment of the stably transfected LST-R1 cell lines may lay a foundation to explore the roles of galectin-1 in laterally spreading tumor.