The relationship between phosphorylation at Ser3 of cofilin1 and Taxol resistance of ovarian cancer in elderly female patients / 中华老年医学杂志

ABSTRACT

Objectives To analyze the relationship between phosphorylation of serine-3 of cofilin1 and Taxol resistance of ovarian cancer and to evaluate the prognostic value of cofilin1 phosphorylation in estimating ovarian cancer survival using clinical samples.Methods Wild type (WT) plasmids with over-expression of wild cofilin1,S3L plasmids with over-expression of cofilin1 and inhibited phosphorylation at serine-3,and siRNA-C plasmids with down-regulation of cofilin1 were constructed using molecular biology techniques.After the SKOV3 and SK-TR30 cell-lines were transfected with these plasmids,changes in biological characteristics and drug resistance after instant transfection were compared.Fifty-one elderly female patients with microscopically confirmed ovarian cancer,who had received chemotherapy with Taxol and cis-platinum (TC)after surgery,including 30 chemo-sensitive and 21 chemo-resistant cases,were recruited in this study.Immunohistochemical methods were used to detect the expression of cofilinl and phosphorylated cofilin in tissue sections from the two groups.Progression free survival(PFS)was analyzed.Results Compared with the control group,the proportion of cells increased at the G0/G1 phase(P=0.034)and decreased at the S phase (P=0.031),and the apoptosis rate decreased(P=0.020),in SKOV3 cells with high expression of cofilin1.However,these characteristics disappeared when the wild type was replaced with the inactive mutant S3L.When cofilin1 expression was down-regulated in SK-TR30 cells,the proportion of cells at the G0/G1 phase decreased(P=0.020).The expression of cofilin1 was detected in 56.7 ％ (17/30)and 57.1％ (12/21),respectively,sections of ovarian tumor tissues of the chemo-sensitive and chemoresistant groups,and there was no statistic difference (x2=0.332,P =0.943)between the two groups.The expression of phosphorylated cofilin was much higher in the chemo-resistant group (85.7％ or 18/21)than in the chemo-sensitive group (53.3％ or 16/30),and the difference was statistically significant(x2=5.829,P=0.016).The higher expression of phosphorylated cofilin was also correlated with shorter PFS(x2 =21.440,P＜0.01,95％ CI0.068-0.883),especially in the chemo-sensitive group.Conclusions Serine-3 phosphorylation status of cofilin 1 is associated with paclitaxel resistance in ovarian cancer,but the underlying mechanisms of regulation need further investigation.