Expression Of Mica On Human Ovarian Cancer Cell Line SKOV3/CDDP And Its Effect On Cytotoxicity Of Natural Killer Cells

Objective: To analyze the expression of MICA on human ovarian cancercell line SKOV3and SKOV3/CDDP and investigate its impact on cytotoxicityof natural killer cells.Methods:1Human ovarian cancer cell SKOV3and SKOV3/CDDP resuscitative andculture,cells morphological were observed by inverted microscope.2Check the IC50of the drug-resistant ovarian cancer cell SKOV3/CDDP toSKOV3through MTT,and calculate resistant index.3Expression of MICA on the surface of SKOV3and SKOV3/CDDP cells wasanalyzed by flow cytometry.4Peripheral blood mononuclear cells(PBMCs) were separated in healthpersons by Ficoll density gradient centrifugation.5Cytotoxicity of NK cells against SKOV3and SKOV3/CDDP cells wasevaluated by MTT assay at different effector-to-target ratios(E:T).Results:1The IC50for cisplatin of SKOV3and SKOV3/CDDP was7.07and35.77mg/L. The resistance multiple was5.06.2The expression of MICA on SKOV3cells was higher than that onSKOV3/CDDP cells, and the difference among two cell lines was significant(P<0.05).3NK cells displayed highly in vitro cytotoxicity against SKOV3andSKOV3/CDDP cells with a mean cell lysis rate of(15.50±2.07)%,(10.48±0.95)%；(32.68±1.42)%,(21.46±1.57)%；(46.99±3.13)%,(34.21±4.40)%；(64.00±2.19)%,(55.95±3.47)%, respectively, correspondi-ng to the E: T ratiosof5:1,10∶1,20∶1,and40:1(P<0.01). Conclusion: Expression of MICA on SKOV3and SKOV3/CDDP cells iscorrelated with NK cell-mediated lysis, there must exist immune escapemechanisms in cisplatin resistant SKOV3/CDDP cells.