ZEB1过表达对乳腺浸润性导管癌细胞增殖与转移潜能影响

Up-regulation of ZEB1 suppresses breast invasive carcinoma cells proliferation,migration and invasion

目的乳腺浸润性导管癌(breast invasive carcinoma,BRCA)在乳腺癌中最常见,比导管原位癌恶性程度更高,预后和治疗效果不乐观。本研究通过检测BRCA细胞中E盒锌指结合蛋白(zinc finger E-box binding homeobox 1,ZEB1)的表达,分析其过表达对人BRCA细胞体外增殖、迁移和侵袭能力的影响,探讨其与BRCA发生发展的关系。方法通过蛋白质印迹法检测BRCA细胞中ZEB1蛋白水平的表达情况,另构建过表达ZEB1BRCA细胞并通过蛋白质印迹法确认其过表达水平。采用细胞计数盒8(cell counting kit 8,CCK8)法和Transwell实验分别检测过表达ZEB1对BRCA细胞增殖、迁移和侵袭的影响。结果蛋白质印迹法结果显示,ZEB1在BRCA细胞HCC38和BT474中的表达分别为0.28±0.02和0.22±0.01,低于正常乳腺上皮细胞(0.90±0.06),差异有统计学意义,t值分别为23.56和18.33,均P<0.001。CCK8实验结果显示,HCC38细胞ZEB1过表达组和Vector组经2因素分析结果显示F组别=6.610,P组别=0.042;F时间=9.236,P时间=0.963;F组别×时间=26.287,P组别×时间<0.001。这表明处理药物的主效应差异有统计学意义,而且药物与时间存在协同作用。ZEB1过表达组在第4天和第5天时的细胞增殖活性低于Vector组,且差异有统计学意义(t4d=4.370,P4d=0.001;t5d=5.627,P5d=0.001);BT474细胞ZEB1过表达组和Vector组经2因素分析结果显示F组别=6.737,P组别=0.039;F时间=14.619,P时间=0.921;F组别×时间=267.723,P组别×时间<0.001。这表明处理药物的主效应差异有统计学意义,而且药物与时间存在协同作用。BT474细胞ZEB1过表达组在第4天和第5天时,细胞增殖活性低于Vector组,差异有统计学意义(t4d=3.682,P4d=0.001;t5d=6.819,P5d<0.001)。Transwell迁移和侵袭实验发现,在HCC38细胞中过表达ZEB1,细胞迁移数目为41±7.94,少于Vector组82.33±7.09,t=4.28,P=0.003;在BT474细胞中过表达ZEB1,细胞迁移数目为44.33±6.11,也少于对应的Vector组89.33±5.69,t=5.51,P=0.006;过表达ZEB1的HCC38细胞,细胞侵袭数目为22.33±4.04,少于对照66.33±8.74,t=2.41,P=0.001;过表达ZEB1的BT474细胞,细胞侵袭数目为21.33±2.52,少于Vector组62.67±6.66,t=3.07,P=0.004。结论ZEB1在BRCA细胞中低表达,过表达ZEB1抑制BRCA细胞的增殖、迁移和侵袭能力。

OBJECTIVE Breast invasive carcinoma(BRCA)which is the most common subtype of breast carcinoma has poor therapeutic effects and prognosis,which is more malignant compared with ductal carcinoma in situ.This study aimed to explore the expression of zinc finger E-box binding homeobox 1(ZEB1)in breast invasive carcinoma cell lines and the effects of ZEB1 on cell proliferation,migration and invasion of BRCA cells.METHODS Western blot was performed to measure ZEB1 expression both in BRCA cell lines and ZEB1 overexpression transfected cell lines.Cell counting kit 8(CCK8)and transwell assays were used to detect the effects of up-regulation of ZEB1 on the proliferation,migration and invasion of BRCA cell lines.RESULTS The expression of ZEB1 at protein level was lower in BRCA cell lines HCC38 and BT474(0.28±0.02;0.22±0.01)than that of in normal breast epithelia cells(0.90±0.06)detected by western blot,both P<0.001,t=23.56,18.33,respectively.The data from CCK8 assay were analyzed by 2 factors analysis in ZEB1 overexpression group and Vector group of HCC38 cells,Fgroups=6.610,Pgroups=0.042;Ftime=9.236,Ptime=0.963;Fgroups×time=26.287,Pgroups×time<0.001,which meant that the main effect of the treated drug was statistically significant,and there was a synergistic effect between the drug and time.The cell proliferation activities in ZEB1 overexpression group were significantly decreased compared to Vector group on the 4 th and 5 th day(t4 d=4.370,P4 d=0.001;t5 d=5.627,P5 d=0.001);Similarly,the data in ZEB1 overexpression group and Vector group of BT474 cells were also analyzed by 2 factors analysis,Fgroups=6.737,Pgroups=0.039;Ftime=14.619,Ptime=0.921;Fgroups×time=267.723,Pgroups×time<0.001,which showed that the main effect of the treated drug was statistically significant,and there was a synergistic effect between the drug and time.The cell proliferation activities in BT474 cells with ZEB1 overexpression were significantly decreased compared to Vector group on the 4 th and 5 th day(t4 d=3.682,P4 d=0.001;t5 d=6.819,P5 d<0.001).Transwell migration and invasion assays results showed that the migratory and invasive abilities of breast invasive carcinoma cells with ZEB1 overexpression were remarkably decreased compared with negative control(migratory cell number in HCC38:41±7.94 vs 82.33±7.09,t=4.28,P=0.003;migratory cell number in BT474:44.33±6.11 vs 89.33±5.69,t=5.51,P=0.006;invasive cell number in HCC38:22.33±4.04 vs 66.33±8.74,t=2.41,P=0.001;invasive cell number in BT474:21.33±2.52 vs 62.67±6.66,t=3.07,P=0.004).Overexpression of ZEB1 in BRCA cell lines showed reduced proliferation,migration invasion abilities compared with the negative controls.CONCLUSIONS ZEB1 is down-regulated in BRCA tissues and cell lines.ZEB1 overexpression suppresses cell proliferation,migration and invasion of BRCA cells.