CircITGB6调节miR-542-3p/PCNA轴对卵巢癌细胞顺铂耐药性的影响及其机制

Effect and Mechanism of CircITGB6 on Cisplatin Resistance in Ovarian Cancer Cells by Regulating miR-542-3p/PCNA Axis

目的:探讨环状RNA(Circ)ITGB6调节微小RNA(miR)-542-3p/增殖细胞核抗原(PCNA)轴对卵巢癌(OC)细胞顺铂(DDP)耐药性的影响及其机制。方法:qRT-PCR检测OC组织及正常卵巢组织、SKOV3、SKOV3/DDP、正常卵巢上皮细胞系(IOSE-80)中CircITGB6、miR-542-3p、PCNA mRNA表达水平;SKOV3/DDP设置为对照组(不作处理)、干扰(si CircITGB6)组(转染si CircITGB6)、阴性对照(si NC)组(转染si NC)、si CircITGB6+抑制物阴性对照(inhibitor NC)组(共转染si CircITGB6、inhibitor NC)、si CircITGB6+miR-542-3p抑制物(miR-542-3p inhibitor)组(共转染si CircITGB6、miR-542-3p inhibitor)。流式细胞仪、CCK-8、qRT-PCR分别检测各组SKOV3/DDP细胞中凋亡、增殖、耐药性及CircITGB6、miR-542-3p、PCNA mRNA表达水平;双荧光素酶验证miR-542-3p与CircITGB6、PCNA的靶向关系;Western blot检测PCNA、Bcl-2相关X蛋白(Bax)、细胞增殖相关核抗原(Ki-67)。结果:OC组织中CircITGB6(1.66±0.17比0.95±0.10)、PCNA mRNA(1.59±0.16比0.98±0.10)表达高于正常卵巢组织,miR-542-3p表达(0.64±0.07比1.06±0.11)降低(均P<0.05);IOSE-80、SKOV3、SKOV3/DDP中CircITGB6、PCNA mRNA表达依次增加,miR-542-3p表达依次减少(P<0.05);与对照组、si NC组相比,si CircITGB6组细胞增殖率及IC50、CircITGB6(1.21±0.13比1.88±0.19、1.84±0.19)、Ki-67、PCNA显著降低,凋亡率及Bax、miR-542-3p表达(0.86±0.09比0.51±0.06、0.55±0.06)显著增加(均P<0.05);与si CircITGB6+inhibitor NC组相比,CircITGB6+miR-542-3p inhibitor组细胞增殖率及IC50、Ki-67、PCNA显著增加,凋亡率及Bax、miR-542-3p表达显著降低(均P<0.05)。结论:干扰CircITGB6表达可通过调节miR-542-3p/PCNA轴降低SKOV3对DDP的耐药性。

Objective:To investigate the influences of circular RNA(Circ)ITGB6 on cisplatin(DDP)resistance of ovarian cancer(OC)cells by regulating miR-542-3p/proliferating cell nuclear antigen(PCNA)axis and its mechanism.Methods:The expression levels of CircITGB6,miR-542-3p,PCNA mRNA in OC tissues,normal ovarian tissues,SKOV3,SKOV3/DDP and normal ovarian epithelial cell line(IOSE-80)were detected by qRT-PCR;SKOV3/DDP was set as control group(no treatment),interference(si CircITGB6)group(transfected with si CircITGB6),negative control(si NC)group(transfected with si NC),si CircITGB6+inhibitor negative control(inhibitor NC)group(co-transfected with si CircITGB6 and inhibitor NC),and si CircITGB6+miR-542-3p inhibitor group(co-transfected with si CircITGB6 and miR-542-3p inhibitor).Apoptosis,proliferation,drug resistance,and the expression levels of CircITGB6,miR-542-3p,PCNA mRNA in SKOV3/DDP cells of each group were detected by flow cytometry,CCK-8 and qRT PCR respectively;double luciferase was used to verify the targeting relationship between miR-542-3p and CircITGB6,PCNA;the PCNA,Bcl-2 associated X protein(Bax)and cell proliferation related nuclear antigen(Ki-67)were detected by Western blot.Results:The expression of CircITGB6(1.66±0.17 vs 0.95±0.10)and PCNA mRNA(1.59±0.16 vs 0.98±0.10)in OC tissues was higher than that in normal ovarian tissues,and the expression of miR-542-3p(0.64±0.07 vs 1.06±0.11)was lower(all P<0.05);the expression of CircITGB6 and PCNA mRNA in IOSE-80,SKOV3 and SKOV3/DDP increased in turn,the expression of miR-542-3p decreased in turn(P<0.05);compared with the control group and the si NC group,the cell proliferation rate and IC50,CircITGB6(1.21±0.13 vs 1.88±0.19,1.84±0.19),Ki-67,PCNA in the si CircITGB6 group were obviously reduced,the apoptosis rate and expression of Bax and miR-542-3p(0.86±0.09 vs 0.51±0.06,0.55±0.06)were obviously increased(all P<0.05);compared with the si CircITGB6+inhibitor NC group,the cell proliferation rate and IC50,Ki-67,PCNA in the CircITGB6+miR-542-3p inhibitor group were obviously increased,the apoptosis rate and the expression of Bax and miR-542-3p were obviously decreased(all P<0.05).Conclusion:Interfering with CircITGB6 expression can reduce the resistance of SKOV3 to DDP by regulating miR-542-3p/PCNA axis.