脑胶质瘤组织RRM1表达临床意义

Expression of RRM1 and its role in brain glioma

目的糖核苷酸还原酶M1(ribonucleotide reductase subunit M1,RRM1)是广泛关注的癌相关基因,也是DNA合成的限速酶。RRM1在恶性胶质瘤中表达水平以及在恶性胶质瘤发生和发展中发挥何种作用,至今仍然不清楚。本研究旨在探讨恶性胶质瘤中RRM1的表达水平,及其在恶性胶质瘤细胞生长、迁移、克隆形成和体内成瘤中的作用,以期为恶性胶质瘤治疗提供新思路。方法回顾性研究华中科技大学同济医学院附属武汉中心医院病理科2016-01-01-2016-12-31有完整随访资料的62例恶性胶质瘤。应用免疫组织化学技术检测62例恶性胶质瘤肿瘤及周围正常脑组织中RRM1的表达,利用病毒转染的方法抑制恶性胶质瘤细胞中RRM1的表达,并观察RRM1沉默对恶性胶质瘤细胞生长、迁移、克隆形成和体内成瘤的影响。结果恶性胶质瘤组织中RRM1阳性表达率为64.5%(40/62),而肿瘤周边正常脑组织中表达水平较低,甚至完全不表达。40例高表达RRM1的患者生存时间为34.7个月,明显短于22例低表达RRM1患者的生存时间(21.5个月),差异有统计学意义,χ2=6.605,P=0.007。RRM1表达下调后,H4细胞的增殖活性明显降低,且H4细胞中Cyclin D1和p-Rb表达水平明显下降。RRM1沉默组的H4细胞划痕区域的细胞数量为(20±12)个,明显少于对照组(80±15)个,t=3.287,P=0.003。RRM1沉默组中,穿过基质胶的H4-RRM1-细胞数量为(46±8)个,明显少于对照组(94±11)个,t=5.841,P=0.006。H4-RRM1-细胞组肿瘤体积为(214.4±53.6)mm3,明显小于H4细胞组肿瘤体积(601.5±84.5)mm3,t=4.257,P=0.001。H4-RRM1-细胞组肿瘤标本中Ki-67表达水平明显低于H4细胞组肿瘤标本Ki-67表达水平。H4-RRM1-细胞组裸鼠存活时间为(42.7±4.7)周,明显长于H4细胞组裸鼠存活时间(32.4±4.6)周,差异有统计学意义,χ2=4.571,P=0.001。结论恶性胶质瘤中高表达RRM1,抑制RRM1可有效抑制恶性胶质瘤细胞的恶性生物学行为,有望成为恶性胶质瘤生物治疗的分子靶点。

OBJECTIVE Ribonucleotide reductase subunit M1（RRM1）,the limited enzyme in DNA synthesis,has been paid extensive attention.However,the expression pattern of RRM1 in brain glioma is still unclear.The aim of this study is to evaluate the expression of RRM1 in glioma and the role of RMM1 in the proliferation,migration,invasion,clone formation and tumorigenesis of glioma cells.METHODS Totally 62 glioma cases were collected from January 1 st 2016 to December 31 st 2016 in the Department of Pathology,Central Hospital of Wuhan.Immunohistochemistry was applied to detect the expression of RRM1 in 62 cases of glioma and normal brain tissues.The roles of RRM1 in the proliferation,migration,invasion,clone formation and tumorigenesis of glioma cells were determined when RRM1 was silenced.RESULTS Positive expression of RRM1（40/62,64.5%）was enhanced significantly in glioma when compared with normal brain.Patients with high RRM1 expression had a poor prognosis（21.5 months）as compared to patients with low expression（34.7 months,χ2=6.605,P=0.007）.Silence of RRM1 suppressed the proliferation activity and the expression levels of Cyclin D1 and p-Rb of of H4 cells.The results of wound healing analysis showed that the number of cells of H4-RRM1-were larger（80±15）in the wound area in H4-RRM1-group than in H4 cell group（20±12,t=3.287,P=0.003）.The tumor volume of H4-RRM1-cells[（214.4±53.6）mm3]was significantly smaller than that of H4 cells[（601.5±84.5）mm3,t=4.257,P=0.001].The expression level of Ki-67 was decreased in H4-RRM1-cell xenograft tumor when compared with H4 cells.Mice with H4 cells xenograft tumor have a poor prognosis[（32.4±4.6）w]as compared to mice with H4-RRM1-cell xenograft tumor[（42.7±4.7）w,χ2=4.571,P=0.001].CONCLUSION RRM1 was highly expressed in glioma and blocking of RRM1 offered a promising strategy for the treatment of glioma.