The Influence Of MiR-34a On Biological Characteristics Of Ovarian Cancer Stem Cells

Objective: To investigate the effect of miR-34a expression and biologicalcharacteristics of ovarian cancer stem cells．Methods: In this study, epithelial ovarian cancer cell line A2780as sample andCD133as a Marker. CD133+cells were isolated from A2780by flow cytometry.Cloning experiments validate the biological characteristics of ovarian cancer stemcells in CD133+cells. The expression of miR-34a in CD133+cells werecomparedand tested by RT-PCR. Transfection the synthetic miR-34a recombinant plasmid toCD133+cells. To observe the changes of biological characteristics in ovarian stemcells, including proliferation and chemosensitivity by MTT, tumor detectioncapability by subcutaneously into nude mice.Results: Cultured for14days, colony formation of CD133+cells was significantlyhigher than CD133-cells (P <0.01), and CD133+cells to form larger clones;expression of miR-34a was lower in CD133+cells; After tainning1、2、3、4、5、6、7d, transfected miR-34a CD133+cells compared with non-transfected miR-34a CD133+cells, the proliferation ability of miR-34a CD133+cell was decline (P<0.05); After using low to high concentrations of paclitaxel, transfected miR-34aCD133+was lower resistance and the difference of drug sensitivity was statisticallysignificant (P<0.01); Transfected miR-34a CD133+cells compared thetumorigenesis ability with non-transfected miR-34a CD133+cells, the difference oftumorigenicity was statistically significant. The same number of untransfected miR-34a CD133+cells may be formed larger tumors the same point in time, and shorter incubation period of tumor formation.Conclusion：1. CD133can be used as one of markers for isolating ovarian cancerstem cells;2. miR-34a in ovarian cancer stem cells was low expression;3. miR-34aplay a action of potential suppressor gene in ovarian cancer. To increase theexpression of miR-34a, the proliferation ability, tumor formation ability and drugresistance of cells were inhibited;4. miR-34a can be a potential gene and a newbiological approach for the treatment of ovarian cancer.