Cytotoxic Effect Of Photodynamic Therapy On High/Low Expression Of KI67 In Cervical Cancer Cells

ObjectiveTo evaluate the cytotoxic effect of Photodynamic Therapy(PDT)on cervical cancer cells with high/low expression of Ki67.MethodsCervical cancer HELA cells were cultured and randomly divided into three groups.The first group was not treated,the second group was treated with Ki67 NC-RNA,and the third group was treated with Ki67 siRNA,which were respectively defined as non-knockdown group,NC group and Ki67 knockdown group.Western Blot assay was performed to detect Ki67 expression level,making sure the Ki67 knock down effect is achieved.CCK8 assay and scratch assay were performed on cervical cancer HELA cells in non-knockdown group and Ki67 knockdown group,respectively,to detect cell proliferation and migration ability.Then,isometric PDT was performed on HELA cells in the non-knockdown group and the knockdown group,respectively.After PDT,the supernatant of HELA cells was observed under the microscope,and CCK8 experiment and scratch experiment were performed again to detect whether the proliferation and migration ability of HELA cells changed The sensitivity of HELA cells with high/low Ki67 expression to Photodynamic Therapy was analyzed.ResultsWestern Blot results showed there was no significant difference in Ki67 protein expression between NC group and non-knockdown group,and Ki67 protein expression in non-knockdown group was higher than that in Ki67 knockdown group.The results of CCK8 showed,the number of cells in the non-knockdown group(P<0.05)and the knockdown group(P<0.05)showed an increasing trend from day 1 to day 5,and the cell growth rate in the non-knockdown group was higher than that in the Ki67 knockdown group(P<0.05).According to the results of scratch experiment,24 hours after scratch,cells in the non-knock group(P<0.05)and Ki67 knockdown group(P<0.05)had scratch healing,and the mobility ofthe non-knock group was higher than that of Ki67 knockdown group(P<0.05).After that,the non-knockout group and the Ki67 knockdown group were subjected to PDT(5-aminolevulinic acid,5-ALA,concentration of 3 mmol/L,incubation for 6 hours,laser wavelength of 630 nm,energy of 15 J/cm2,power of 2 w)under the same conditions,and then CCK8 experiment was performed on the two groups’ cells.The results showed that,from day 1 to day 5,the growth of cell number in non-knockdown group(P<0.05)and Ki67 knockdown group(P<0.05)was significantly slowed down.On the 1st to 2nd day,the inhibitory rate of cell viability in the non-knock group was higher than that in the Ki67 knockdown group(P>0.05).The results of scratch test after PDT showed that 24h after scratch,cell mobility decreased in both the non-knock group(P<0.05)and Ki67 knockdown group(P<0.05),and the decrease of cell mobility in the non-knock group was greater than that in the Ki67 knockdown group(P<0.05).After PDT,the cell morphology of HELA cells in the non-knockdown group and Ki67 knockdown group was observed to change compared with that before PDT under the microscope magnification of 20 times.The cell volume was reduced,the nucleus was pressed to one side of the cell edge,and a large and bright vesicle bulged out on the other side of the cell.ConclusionPDT has the cytotoxic effect on cervical cancer cells,and the cytotoxic effect of PDT on cervical cancer with high Ki67 expression is stronger than that of cervical cancer with low Ki67 expression.