circNHSL1通过调控miR-125b-5p/HMGB3轴抑制人乳腺癌细胞系增殖及促凋亡

circNHSL1 inhibits proliferation and promotes apoptosis of human breast cancer cell line through regulating miR-125b-5p/HMGB3 axis

目的探讨circNHSL1调控miR-125b-5p/HMGB3轴对乳腺癌细胞生物行为的影响。方法将乳腺癌细胞系T47D分为si-NC组、si-circNHSL1组、miR-NC组、miR-125b-5p mimic组、si-circNHSL1+miR-125b-5p inhibitor组。RT-qPCR测定circNHSL1和miR-125b-5p在乳腺癌组织和癌旁组织中的表达。Western blot检测高迁移率族蛋白3(HMGB3)蛋白的表达。双荧光素酶报告基因实验确定circNHSL1与miR-125b-5p、miR-125b-5p与HMGB3之间的相互作用。CCK-8法检测增殖抑制率;集落形成实验检测集落形成数;流式细胞术检测凋亡率;Transwell实验检测迁移和侵袭细胞数。结果与癌旁组织比较,乳腺癌组织中circNHSL1和HMGB3表达升高(P<0.05),miR-125b-5p相对水平显著降低(P<0.05)。miR-125b-5p分别与circNHSL1、HMGB3直接结合。circNHSL1敲低下调T47D细胞中circNHSL1和HMGB3表达,上调miR-125b-5p表达(P<0.05);而miR-125b-5p mimic转染后上调miR-125b-5p表达,下调HMGB3表达(P<0.05);且miR-125b-5p inhibitor转染能够逆转circNHSL1沉默对miR-125b-5p以及HMGB3表达的影响。circNHSL1低表达或miR-125b-5p高表达增加T47D细胞抑制率、集落形成数以及细胞凋亡率,减少迁移数、侵袭数(P<0.05);且miR-125b-5p inhibitor的转染挽救circNHSL1沉默对细胞表型的影响(P<0.05)。结论干扰circNHSL1通过上调miR-125b-5p/HMGB3轴可促进乳腺癌细胞凋亡,抑制其增殖、迁移和侵袭。

Objective To investigate the regulation of miR-125b-5p/HMGB3 axis by circNHSL1 on the biological behavior of breast cancer cells.Methods The breast cancer cells T47D were divided into si-NC group,si-circNHSL1 group,miR-NC group,and miR-125b-5p mimic group and si-circNHSL1+miR-125b-5p inhibitor group.The expression of circNHSL1 and miR-125b-5p in breast cancer tissues and adjacent tissues was determined using RT-qPCR.Western blot was conducted to detect the protein expression of high mobility group protein 3(HMGB3).Dual luciferase reporter gene assay was used to confirm the interaction between circNHSL1 and miR-125b-5p,miR-125b-5p and HMGB3.The proliferation rate was measured by CCK-8 method;the colony formation assay was applied to detect the colony formation numbers;flow cytometry was used to measure cell apoptosis rate;Transwell assay was used to detect the numbers of migratory and invasive cells.Results Compared with adjacent tissues,circNHSL1 and HMGB3 expression in breast cancer tissues was significantly increased(P<0.05),while the expression of miR-125b-5p was significantly decreased(P<0.05).miR-125b-5p directly bound to circNHSL1 and HMGB3,respectively.The circNHSL1 knockdown down regulated circNHSL1 and HMGB3 expression and upregulated miR-125b-5p expression in T47D cells(P<0.05).After transfection with miR-125b-5p mimic,miR-125b-5p expression was up-regulated and HMGB3 expression was down-regulated(P<0.05).Moreover,transfection of miR-125b-5p inhibitor reversed the effect of circNHSL1 silencing on the expression of miR-125b-5p and HMGB3.Low expression of circNHSL1 or high expression of miR-125b-5p increased the cell inhibition rate,colony formation and apoptosis rate of T47D and decreased the number of migratory and invasive cells(P<0.05).Moreover,transfection of miR-125b-5p inhibitor saved the effect of circNHSL1 silencing on cell phenotypes(P<0.05).Conclusions Interfering with circNHSL1 might promote cell apoptosis and inhibit cell proliferation,migration and invasion in breast cancer cell by up-regulating the miR-125b-5p/HMGB3 axis.