RESUMEN
AIM: To isolate and clone the vincristine-resistance-related genes in gastric cancer SGC7901 cell line and to clarify the multidrug-resistant molecular mechanism of gastric cancer cells. METHODS: The modified differential-display polymerase chain reaction (DD-PCR) was used to examine differences in the mRNA composition of Vincristine-resistant gastric cancer SGC 7901 cells (SGC7901/VCR), induced by vincristine sulfate versus SGC7901cells. The differentially expressed cDNA fragments were confirmed by reverse Northern analysis, sequencing, BLAST analysis and Northern bolt analysis. RESULTS: The DD-PCR identified that 54 cDNA fragments were preferentially expressed in SGC 7901/VCR cells. When these cDNA fragments were analyzed by reverse Northern blot, twenty were reproducibly expressed at high level in SGC7901/VCR. Sequencing and BLAST analysis revealed that seven of the genes were known genes:ADP-ribosylation factor 4, Cytochrome oxidase subunit II, Ss-A/Ro ribonucleoprtein autoantigen 60kd subunit,ribosomal protein S13, galaectin-8 gene, oligophrenin 1 mRNA, ribosomal protein L23 mRNA; thirteen of the genes were unknown genes. The length and abundance of the four unknown genes were further confirmed by Northern blot analysis. CONCLUSION: The twenty differential known and unknown genes may be related to the vincristine-resistant mechanism in human gastric cancer SGC7901 cell line.