Abstract: Objective To investigate the expression of microRNA-100(miR-100) and the relationship with cisplatin resistance in
human ovarian epithelial cancer SKOV3/DDP cells. Methods The SKOV3/DDP cells were transfected with the mimics or
inhibitor of miR-100 or negative control RNA (NC) or inhibitor negative control RNA (inhibitor NC) by lipofectamine 2000.
The experiment was divided into six groups: SKOV3 group, SKOV3/DDP group, miR-100 mimices group, NC group, miR-100
inhibitor group and inhibitor NC group. The expression of miR-100 and the cisplatin IC50 were measured by real-time PCR and
CCK8 assay respectively. Results（1）The cisplatin resistance index of SKOV3/DDP was 2.23;（2）The express level of miR-100
in SKOV3/DDP cells was significantly lower than that in SKOV3 cells (P<0.001);（3）After transfected with miR-100 mimics,
SKOV3/DDP cells showed that the level of miR-100 was 38.29 times higher than that in the NC group(P<0.01). The cisplatin IC50
of miR-100 mimices group was significantly lower than that in the NC group (P<0.001); (4) After transfected with miR-100
inhibitor, the level of miR-100 0f SKOV3/DDP was decreased by 97.7%. The cisplatin IC50 of miR-100 inhibitor group was
significantly increased as compared with that in the inhibitor NC group (P<0.001). Conclusion The expression of miR-100 is
downregulated in SKOV3/DDP cells. Overexpressing miR-100 may effectively increase the sensitivity to cisplatin of human
ovarian epithelial cancer SKOV3/DDP cells and may reverse cisplatin-resistance of EOC (epithelial ovarian cancer).