Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a ...Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgo 1 and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgo 1 is a substrate of NEK2A and the phosphorylation sites were mapped to Ser^14 and Ser^507 as judged by the incorporation of 32^P. Although such phosphorylation is not required for assembly of HsSgo 1 to the kinetochore, expression of non-phosphorylatable mutant HsSgo 1 perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation ofHsSgo 1 in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgo 1 provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.展开更多
目的研究miR-195调控中心体相关激酶2(NEK2)对前列腺癌细胞增殖的影响。方法 Western blot检测在稳定表达和抑制表达miR-195的LNCaP细胞株中NEK2蛋白的表达水平;构建克隆编码miR-195的序列片段慢病毒载体和表达NEK2的质粒载体,对转染空...目的研究miR-195调控中心体相关激酶2(NEK2)对前列腺癌细胞增殖的影响。方法 Western blot检测在稳定表达和抑制表达miR-195的LNCaP细胞株中NEK2蛋白的表达水平;构建克隆编码miR-195的序列片段慢病毒载体和表达NEK2的质粒载体,对转染空载体和NEK2,以及同时转染了miR-195模拟物和NEK2、miR-195模拟物和空载体的LNCaP细胞株进行CCK8细胞增殖实验;采用shRNA方法构建干扰NEK2基因表达质粒,NEK2抑制成功和miR-195过表达的LNCaP细胞进行细胞增殖实验,测定si-NC、si-NEK2、si-195的LNCaP细胞的生长速度。结果在过表达miR-195的LNCaP细胞株中NEK2蛋白的表达水平比阴性对照miR-NC的LNCaP细胞株中蛋白表达水平明显降低(P<0.01);相反,在miR-195被抑制表达的LNCaP细胞株中NEK2蛋白的表达水平明显增加(P<0.01)。细胞增殖实验显示转染NEK2基因的LNCaP细胞在72、96h生长速度显著快于转染空载体的细胞(P<0.01);转染miR-195模拟物和NEK2的LNCaP细胞在72、96h生长速度显著慢于单纯转染NEK2的LNCaP细胞(P<0.01);si-NEK2的LNCaP细胞在72、96h生长速度明显慢于siNC,且与miR-195过表达的LNCaP细胞相似。结论 miR-195负性调控相关下游基因NEK2的表达,抑制前列腺癌细胞的增殖,初步验证了miRNA-195-NEK2信号轴在前列腺癌中的作用。展开更多
三阴性乳腺癌(triple-negative breast cancer,TNBC)的主要治疗方式是化疗,而化疗耐药是TNBC治疗的难点.发现在TNBC细胞系(MDA-MB-231、BT-549)中,Nek2A的表达异常增高,Nek2A-siRNA转染TNBC细胞系,降低Nek2A表达后,TNBC细胞增殖降低,化...三阴性乳腺癌(triple-negative breast cancer,TNBC)的主要治疗方式是化疗,而化疗耐药是TNBC治疗的难点.发现在TNBC细胞系(MDA-MB-231、BT-549)中,Nek2A的表达异常增高,Nek2A-siRNA转染TNBC细胞系,降低Nek2A表达后,TNBC细胞增殖降低,化疗药物联合Nek2A-siRNA组细胞增殖降低更明显.降低Nek2A表达可以增强紫杉醇及顺铂的化疗敏感性.检测裸鼠体内成瘤情况发现:Nek2A-siRNA联合紫杉醇(TAX)及顺铂(DDP)化疗药物组肿物最小.结果表明,Nek2A在TNBC中表达异常增高,并且降低Nek2A表达可以增强紫杉醇及顺铂化疗敏感性.展开更多
目的研究NEK2(中心体相关激酶2)在前列腺癌和良性组织中的表达情况及其与前列腺癌预后的相关性。方法运用qRT-PCR检测NEK2在前列腺癌和癌旁组织的表达差异,通过组织芯片免疫组化染色检测的方法检验NEK2在前列腺癌和癌旁组织的表达情况,...目的研究NEK2(中心体相关激酶2)在前列腺癌和良性组织中的表达情况及其与前列腺癌预后的相关性。方法运用qRT-PCR检测NEK2在前列腺癌和癌旁组织的表达差异,通过组织芯片免疫组化染色检测的方法检验NEK2在前列腺癌和癌旁组织的表达情况,最后使用Taylor的数据对NEK2进行生物信息学分析。结果qRT-PCR检测NEK2在前列腺癌组织的表达显著高于癌旁组织(6.93±0.15 vs 5.38±0.4,t=6.25,P=0.003),组织芯片免疫组化结果显示NEK2在前列腺癌组织的表达显著高于癌旁组织(5.84±0.56 vs 4.27±0.49,t=5.38,P<0.001),结合Taylor公用数据库分析,NEK2高表达组患者术后的生化复发生存率减少(χ~2=4.33,P=0.037),NEK2高表达组和低表达组在前列腺癌总体生存率上没有明显区别(χ~2=0.27,P=0.605)。结论NEK2参与前列腺癌的发生、发展进程,同前列腺癌发病进程密切相关,通过检测前列腺癌患者NEK2的表达情况,可早期预测生化复发的概率,能够作为判断前列腺癌预后的潜在生物学标志物。展开更多
基金We thank members of our group for insightful discussion during the course of this study.This work was supported by grants from Chinese Academy of Science(KSCX1-YW-R65,KSCX2-YW-H10)National Basic Research Program of China(2002CB713700)+4 种基金Hi-Tech Research and Development Program of China(2001AA215331)Chinese Minister of Education(20020358051 to XY,PCSIRT0413 to XD)National Natural Science Foundation of China(39925018,30270293 to XY,30500183 to XD,30600222 to JY)National Institutes of Health(USA)(DK56292,CA92080)to XY(a Georgia Cancer Coalition Eminent Scholar)JY was supported by China Postdoctor(2005037560).
文摘Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgo 1 and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgo 1 is a substrate of NEK2A and the phosphorylation sites were mapped to Ser^14 and Ser^507 as judged by the incorporation of 32^P. Although such phosphorylation is not required for assembly of HsSgo 1 to the kinetochore, expression of non-phosphorylatable mutant HsSgo 1 perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation ofHsSgo 1 in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgo 1 provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.
文摘目的研究miR-195调控中心体相关激酶2(NEK2)对前列腺癌细胞增殖的影响。方法 Western blot检测在稳定表达和抑制表达miR-195的LNCaP细胞株中NEK2蛋白的表达水平;构建克隆编码miR-195的序列片段慢病毒载体和表达NEK2的质粒载体,对转染空载体和NEK2,以及同时转染了miR-195模拟物和NEK2、miR-195模拟物和空载体的LNCaP细胞株进行CCK8细胞增殖实验;采用shRNA方法构建干扰NEK2基因表达质粒,NEK2抑制成功和miR-195过表达的LNCaP细胞进行细胞增殖实验,测定si-NC、si-NEK2、si-195的LNCaP细胞的生长速度。结果在过表达miR-195的LNCaP细胞株中NEK2蛋白的表达水平比阴性对照miR-NC的LNCaP细胞株中蛋白表达水平明显降低(P<0.01);相反,在miR-195被抑制表达的LNCaP细胞株中NEK2蛋白的表达水平明显增加(P<0.01)。细胞增殖实验显示转染NEK2基因的LNCaP细胞在72、96h生长速度显著快于转染空载体的细胞(P<0.01);转染miR-195模拟物和NEK2的LNCaP细胞在72、96h生长速度显著慢于单纯转染NEK2的LNCaP细胞(P<0.01);si-NEK2的LNCaP细胞在72、96h生长速度明显慢于siNC,且与miR-195过表达的LNCaP细胞相似。结论 miR-195负性调控相关下游基因NEK2的表达,抑制前列腺癌细胞的增殖,初步验证了miRNA-195-NEK2信号轴在前列腺癌中的作用。
文摘三阴性乳腺癌(triple-negative breast cancer,TNBC)的主要治疗方式是化疗,而化疗耐药是TNBC治疗的难点.发现在TNBC细胞系(MDA-MB-231、BT-549)中,Nek2A的表达异常增高,Nek2A-siRNA转染TNBC细胞系,降低Nek2A表达后,TNBC细胞增殖降低,化疗药物联合Nek2A-siRNA组细胞增殖降低更明显.降低Nek2A表达可以增强紫杉醇及顺铂的化疗敏感性.检测裸鼠体内成瘤情况发现:Nek2A-siRNA联合紫杉醇(TAX)及顺铂(DDP)化疗药物组肿物最小.结果表明,Nek2A在TNBC中表达异常增高,并且降低Nek2A表达可以增强紫杉醇及顺铂化疗敏感性.
文摘目的研究NEK2(中心体相关激酶2)在前列腺癌和良性组织中的表达情况及其与前列腺癌预后的相关性。方法运用qRT-PCR检测NEK2在前列腺癌和癌旁组织的表达差异,通过组织芯片免疫组化染色检测的方法检验NEK2在前列腺癌和癌旁组织的表达情况,最后使用Taylor的数据对NEK2进行生物信息学分析。结果qRT-PCR检测NEK2在前列腺癌组织的表达显著高于癌旁组织(6.93±0.15 vs 5.38±0.4,t=6.25,P=0.003),组织芯片免疫组化结果显示NEK2在前列腺癌组织的表达显著高于癌旁组织(5.84±0.56 vs 4.27±0.49,t=5.38,P<0.001),结合Taylor公用数据库分析,NEK2高表达组患者术后的生化复发生存率减少(χ~2=4.33,P=0.037),NEK2高表达组和低表达组在前列腺癌总体生存率上没有明显区别(χ~2=0.27,P=0.605)。结论NEK2参与前列腺癌的发生、发展进程,同前列腺癌发病进程密切相关,通过检测前列腺癌患者NEK2的表达情况,可早期预测生化复发的概率,能够作为判断前列腺癌预后的潜在生物学标志物。
