蛋白质精氨酸甲基转移酶2在乳腺癌细胞中的表达及其对SKBR-3细胞生长特性的影响

Expression of protein arginine methyltransferase 2 in breast cancer cells and its effects on the cell growth properties of breast cancer cell line SKBR-3

目的:探讨蛋白质精氨酸甲基转移酶2(protein arginine methyltransferase2,PRMT2)基因在多种乳腺癌细胞株中的表达情况,以及外源性PRMT2基因过表达对乳腺癌SKBR-3细胞生长特性的影响。方法:采用real-time RT-PCR法检测PRMT2基因在不同乳腺癌细胞株中的表达,并建立稳定表达pcDNA3.1/NT-GFP-PRMT2的SKBR-3细胞株;激光共聚焦显微镜下观察外源性PRMT2蛋白在细胞中的定位,检测在雌激素和雌激素受体(estrogen receptor,ER)拮抗剂4-OHT作用下过表达PRMT2基因对SKBR-3细胞增殖的影响。结果:PRMT2基因在ERα阳性乳腺癌细胞株中表达水平明显高于ERα阴性乳腺癌细胞株;在转染PRMT2基因的SKBR-3细胞株中,雌激素反应元件-荧光素酶报告基因(estrogen response elements-luciferasereporter,ERE-luc)的转录活性明显升高。在无处理因子情况下,外源基因PRMT2在SKBR-3细胞中的表达对细胞的形态及生长速度无明显影响。与未转染及转染GFP空载体的SKBR-3细胞相比,稳定转染PRMT2基因的SKBR-3细胞对雌激素的敏感性明显下降,但其对4-OHT处理的敏感性降低无明显差异。结论:PRMT2基因表达的多少及部位与乳腺癌细胞中ERα的表达密切相关。外源性PRMT2基因在乳腺癌SKBR-3细胞中稳定表达使细胞对雌激素的敏感性降低,但不增加细胞对ER拮抗剂4-OHT的耐药性。

Objective：To explore the expression of protein arginine methyltransferase 2（PRMT2）in diverse breast cancer cell lines and to investigate its effects on the cell growth properties of breast cancer cell line SKBR-3.Methods：The expression of PRMT2 mRNA was detected in estrogen receptor alpha（ERα）-positive and ERα-negative breast cancer cell lines by real-time RT-PCR.The eukaryotic expression plasmid pcDNA3.1/NT-GFP-PRMT2 was transfected into SKBR-3 cells.The expression and location of exogenous PRMT2 protein in the PRMT2-transfected SKBR-3 cells were observed under laser scanning confocal microscope.The effects of PRMT2 overexpression on the proliferation of SKBR-3 cells were measured under different treatments,including 17 beta-estradiol（E2）and 4-hydroxytamoxifen（4-OHT）,individually.Results：The expression of PRMT2 mRNA in ERα-positive breast cancer cell lines was significantly higher than that in ERα-negative cell lines.A stronger transcriptional activity of estrogen response elements-luciferase reporter（ERE-luc）was observed in the PRMT2-transfected SKBR-3 cells cultivated with E2 than those in the GFP-transfected SKBR-3 cells and untransfected SKBR-3 cells.Exogenous PRMT2 expression did not change the growth property and the morphology of SKBR-3 cells without any treatment.The PRMT2-transfected SKBR-3 cells treated with 4-OHT proliferated at the same rate as the naive cells,whereas a stronger inhibition of the proliferation of the PRMT2-transfected SKBR-3 cells cocultivated with E2 was observed.Conclusion：The expressive level and location of PRMT2 were significantly related to the expression of ERα in breast cancer cells.Exogenous PRMT2 expression in breast cancer SKBR-3 cells does not increase the resistance to 4-OHT,and inhibits strongly the cell proliferation in the pre-sence of E2.