ABCG2Gene Regulation Effect On Liver Cancer Cell Biology Behavior

Objective:1Through the up-regulation of ABCG2gene, to observe the effects on resistance, proliferation capacity and invasion ability of SMMC7721cancer cells after over express ABCG2gene.2Through the down-regulation of ABCG2gene, to observe the effects on doxorubicin resistance, proliferation capacity and invasion ability of SMMC7721cancer cells after Interference of ABCG2geneMethods:1The PCDNA3.1(+)-ABCG2recombinant plasmid and thePCDNA3.1(+) empty vector was transfected into ABCG2negative SMMC7721cells with LipofectamineTM2000, the expression of ABCG2gene in transfected cells SMMC7721was detected by Semi-quantitativeRT-PCR and Western-blotting then cell doxorubicin resistance and proliferation was evaluated with MTT assay; finally transwell assay was applied to evaluate the ability of its invasion ability after transfection.2The ABCG2-SiRNA and noscnse-SiRNA was transfected into The ABCG2positive SMMC7721cancer cells with LipofectamineTM2000, the expression of ABCG2gene in transfected cells SMMC7721was detected by Semi-quantitative RT-PCR and Western-blotting, then cell doxorubicin resistance and proliferation was evaluated with MTT assay; finally transwell assay was applied to evaluate the ability of its invasion ability after transfectionResults:1After PCDNA3.1(+)-ABCG2recombinant plasmid was transfected into ABCG2negative SMMC7721cells, the levels of ABCG2protein and mRNA were significantly higher than control group.(P<0.05);The doxorubicin resistance, proliferation and invasion ability were significantly enhanced after over express ABCG2gene; there was no significant difference on the level of ABCG2mRNA and protein expression between the Empty vector control group and the Blank group (P>0.05);also, there was no significant difference in The doxorubicin resistance, proliferation and invasion ability between the Empty vector control group and the Blank group (P>0.05).2After ABCG2-SiRNA was transfected into ABCG2positive SMMC7721cells, the levels of ABCG2protein and mRNA were significantly lower than control group.(P<0.05);The doxorubicin resistance, proliferation and invasion ability were significantly weakened after Interference of ABCG2gene; there was no significant difference on the level of ABCG2mRNA and protein expression between the negative control group and the Blank group (P>0.05);also, there was no significant difference in The doxorubicin resistance, proliferation and invasion ability between the negative control group and the Blank group (P>0.05)Conclusion:The Resistance to chemotherapy, proliferation capacity and invasion ability of hepatoma carcinoma cell may be relation with the ABCG2gene expression levels; Combined with the results of our previous animal experiments:Tumorigenicity of ABCG2-positive cells was significantly higher than ABCG2-negative cells, suggesting that ABCG2-positive liver cancer cells have more cancer stem cell characteristics. Thus, ABCG2may be one of the signs of liver cancer stem cells.