Construction of cDNA representational difference analysis based on two cDNA libraries and identification of garlic inducible expression genes in human gastric cancer cells

AIM: To elucidate molecular mechanism of chemopreventive efficacies of garlic against human gastric cancer (HGC).METHODS: HGC cell line BGC823 was treated with Allitridi (a kind of garlic extract) and Allitridi-treated and parental BGC823 cDNA libraries were constructed respectively by using λ λ λ λ λZAP II vector.cDNA Representational Difference Analysis (cDNA RDA) was performed using BamH I cuttingsite and abundant cDNA messages provided by the libraries.Northern blot analysis was applied to identify the obtained difference products.RESULTS: Two specific cDNA fragments were obtained and characterized to be derived from homo sapiens folate receptorα α α α α (FRα α α α α) gene and calcyclin gene respectively.Northern blot results showed a 4-fold increase in FRα α α α α gene expression level and 9-fold increase in calcyclin mRNA level in BGC823 cells after Allitridi treatment for 72h. CONCLUSION:The method of cDNA RDA based on cDNA libraries combines the high specificity of cDNA RDA with abundant cDNA messages in cDNA library; this expands the application of cDNA library and increases the specificity of cDNA RDA.Up-regulation of FRα α α α α gene and calcyclin gene expressions induced by Allitridi provide valuable molecular evidence for the efficacy garlic in treating HGC as well as other diseases.