GINS, a heterotetramer of SLD5, PSF1, PSF2, and PSF3 proteins, is an emerging chromatin factor recognized to be involved in the initiation and elongation step of DNA replication. Although the yeast and Xenopus GINS ge...GINS, a heterotetramer of SLD5, PSF1, PSF2, and PSF3 proteins, is an emerging chromatin factor recognized to be involved in the initiation and elongation step of DNA replication. Although the yeast and Xenopus GINS genes are well documented, their orthologous genes in higher eukaryotes are not fully characterized. In this study, we report the genomic structure and transcriptional regulation of mammalian GINS genes. Serum stimulation increased the GINS mRNA levels in human cells. Reporter gene assay using putative GINS promoter sequences revealed that the expression of mammalian GINS is regulated by 17β-Estradiolstimulated estrogen receptor a, and human PSF3 acts as a gene responsive to transcription factor E2F1. The goal of this study is to present the current data so as to encourage further work in the field of GINS gene regulation and functions in mammalian cells.展开更多
目的:检测转录因子E2F1与生长阻滞和DNA损伤诱导蛋白45g(GADD45g)基因在急性髓系白血病(AML)患者中表达的相关性,探讨GADD45g是否通过抑制E2F1诱导AML细胞DNA损伤、凋亡、衰老、周期阻滞和提高药物敏感性。方法:选取2013年1月至2016年1...目的:检测转录因子E2F1与生长阻滞和DNA损伤诱导蛋白45g(GADD45g)基因在急性髓系白血病(AML)患者中表达的相关性,探讨GADD45g是否通过抑制E2F1诱导AML细胞DNA损伤、凋亡、衰老、周期阻滞和提高药物敏感性。方法:选取2013年1月至2016年12月中国医学科学院血液病医院初诊为AML患者32例骨髓标本及AML细胞系U937、HL60、THP-1和Molm-13,用q PCR检测组织和细胞中GADD45g和E2F1 m RNA的表达水平,并分析其相关性。构建E2F1过表达载体,并制备重组慢病毒在过表达GADD45g的Molm-13和THP-1细胞中过表达E2F1,通过彗星实验、Annexin V/7AAD流式细胞术、β-半乳糖苷酶染色和PI染色流式细胞术等确定GADD45g是否通过抑制E2F1对AML细胞发挥抑癌作用。结果:AML患者骨髓和细胞系中GADD45g和E2F1 m RNA的表达呈显著负相关(r=–0.663,P<0.01)。GADD45g在AML细胞系中过表达显著抑制了E2F1的表达(均P<0.01)。成功构建同时过表达GADD45g和E2F1的Molm-13和THP-1细胞,与对照组比较,过表达组细胞GADD45g和E2F1蛋白表达水平均显著升高(均P<0.01)。与过表达GADD45g的细胞相比,同时过表达GADD45g和E2F1细胞的凋亡、衰老率和DNA损伤水平均显著降低(均P<0.01);在过表达GADD45g的细胞中过表达E2F1逆转了GADD45g诱导的周期阻滞(均P<0.01),进而降低了过表达GADD45g对化疗药物的敏感性(均P<0.01)。结论:GADD45g通过抑制E2F1在AML中发挥抗肿瘤作用。展开更多
文摘GINS, a heterotetramer of SLD5, PSF1, PSF2, and PSF3 proteins, is an emerging chromatin factor recognized to be involved in the initiation and elongation step of DNA replication. Although the yeast and Xenopus GINS genes are well documented, their orthologous genes in higher eukaryotes are not fully characterized. In this study, we report the genomic structure and transcriptional regulation of mammalian GINS genes. Serum stimulation increased the GINS mRNA levels in human cells. Reporter gene assay using putative GINS promoter sequences revealed that the expression of mammalian GINS is regulated by 17β-Estradiolstimulated estrogen receptor a, and human PSF3 acts as a gene responsive to transcription factor E2F1. The goal of this study is to present the current data so as to encourage further work in the field of GINS gene regulation and functions in mammalian cells.
文摘目的:检测转录因子E2F1与生长阻滞和DNA损伤诱导蛋白45g(GADD45g)基因在急性髓系白血病(AML)患者中表达的相关性,探讨GADD45g是否通过抑制E2F1诱导AML细胞DNA损伤、凋亡、衰老、周期阻滞和提高药物敏感性。方法:选取2013年1月至2016年12月中国医学科学院血液病医院初诊为AML患者32例骨髓标本及AML细胞系U937、HL60、THP-1和Molm-13,用q PCR检测组织和细胞中GADD45g和E2F1 m RNA的表达水平,并分析其相关性。构建E2F1过表达载体,并制备重组慢病毒在过表达GADD45g的Molm-13和THP-1细胞中过表达E2F1,通过彗星实验、Annexin V/7AAD流式细胞术、β-半乳糖苷酶染色和PI染色流式细胞术等确定GADD45g是否通过抑制E2F1对AML细胞发挥抑癌作用。结果:AML患者骨髓和细胞系中GADD45g和E2F1 m RNA的表达呈显著负相关(r=–0.663,P<0.01)。GADD45g在AML细胞系中过表达显著抑制了E2F1的表达(均P<0.01)。成功构建同时过表达GADD45g和E2F1的Molm-13和THP-1细胞,与对照组比较,过表达组细胞GADD45g和E2F1蛋白表达水平均显著升高(均P<0.01)。与过表达GADD45g的细胞相比,同时过表达GADD45g和E2F1细胞的凋亡、衰老率和DNA损伤水平均显著降低(均P<0.01);在过表达GADD45g的细胞中过表达E2F1逆转了GADD45g诱导的周期阻滞(均P<0.01),进而降低了过表达GADD45g对化疗药物的敏感性(均P<0.01)。结论:GADD45g通过抑制E2F1在AML中发挥抗肿瘤作用。
