ABSTRACT
Objective To study the effect of ribosomal protein S13(RPS13) encoding genes on the development of mutidrug resistance (MDR) in human gastric cancer cell line. Methods RPS13 cDNA was amplified by RT-PCR. The sense and antisense eukaryotic expression vectors were constructed by DNA recombination. Gastric cancer cell line SGC7901 and Vincristine-resistant SGC7901/VCR cells were transfected with the sense and antisense recombinant vectors respectively using liposome-mediated method. RNA dot blotting assay was used to verify the changes of mRNA level in stable clones. To investigate effects of the sense, antisense vector transfection on the chemotherapeutic drug sensitivity, thiazolyl blue (MTT) cytotoxicity assay was used. Cell cycle was detected by flow cytometry (FCM). Results Whole length of RPS13 cDNA gene was amplified by RT-PCR. The sense, antisense eukaryotic expression vectors were constructed by the directed cloning of the target genes into eukaryotic expression vector pcDNA 3.1(+). RNA dot blotting assay suggested that mRNA level of the RPS13 was up-regulated in the sense recombinant vector transfected cells, and down-regulated in the antisense recombinant vector transfected cells. By MTT cytotoxicity assay, the enhanced resistance to adriamycin, 5-fluorouracil and vincristine was found in the RPS13 sense recombinant vector transfected SGC7901 cells. RPS13 antisense recombinant vector rendered SGC7901/VCR cells partially sensitive to mitomycin and vincristine. Cell cycle analysis suggested that the proportion of G1, S, and G2 cells was 47.0%, 33.2% and 19.8% respectively in up-regulated RPS13 cells; the proportion of G1, S and G2 cells was 62.9%, 1.0% and 36.1% respectively in down-regulated RPS13 cells. Conclusions RPS13 may take part in the mediation of MDR in gastric cancer cells.