BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in ...BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in the liver,but is depleted in some tumor tissues.However,the functional mechanisms of GAS2 in hepatocellular carcinoma(HCC)are not fully defined.AIM To investigate the function and mechanism of GAS2 in HCC.METHODS GAS2 expression in clinic liver and HCC specimens was analyzed by real-time PCR and western blotting.Cell proliferation was analyzed by counting,MTS,and colony formation assays.Cell cycle analysis was performed by flow cytometry.Cell apoptosis was investigated by Annexin V apoptosis assay and western blotting.RESULTS GAS2 protein expression was lower in HCC than in normal tissues.Overexpression of GAS2 inhibited the proliferation of HCC cells with wide-type p53,while knockdown of GAS2 promoted the proliferation of hepatocytes(P<0.05).Furthermore,GAS2 overexpression impeded the G1-to-S cell cycle transition and arrested more G1 cells,particularly the elevation of sub G1(P<0.01).Apoptosis induced by GAS2 was dependent on p53,which was increased by etoposide addition.The expression of p53 and apoptosis markers was further enhanced when GAS2 was upregulated,but became diminished upon downregulation of GAS2.In the clinic specimen,GAS2 was downregulated in more than 60%of HCCs.The average fold changes of GAS2 expression in tumor tissues were significantly lower than those in paired non-tumor tissues(P<0.05).CONCLUSION GAS2 plays a vital role in HCC cell proliferation and apoptosis,possibly by regulating the cell cycle and p53-dependent apoptosis pathway.展开更多
Objective To investigate the effect of interleukin-6(IL-6)on the human growth hormone(hGH)gene expression in a rat somatotropic pituitary cell line MtT/S.Methods The plasmids containing various lengths of hGH gene 5&#...Objective To investigate the effect of interleukin-6(IL-6)on the human growth hormone(hGH)gene expression in a rat somatotropic pituitary cell line MtT/S.Methods The plasmids containing various lengths of hGH gene 5'-promoter fragments were constructed.Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1(+)with DMRIE-C transfection reagent.After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction pathways,the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism.Results The 103 U/mL IL-6 stimulated GH secretion and synthesis,and promoted the 5'-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control.Among inhibitors of signaling transduction pathways,mitogen-activated protein kinase kinase(MAPKK/MEK)inhibitor PD98059(40 μmol/L)and p38 mitogen-activated protein kinase(MAPK)inhibitor SB203580(5 μmol/L)completely blocked the stimulatory effect of IL-6.Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells.Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity.A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6.The results showed that the stimulatory effect of IL-6 was abolished following deletion of the-196 to-132 bp fragment.Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells.The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK,and a fragment of promoter sequence that spans the-196 to-132 bp of the gene,but may be unlinked with Pit-1 protein.展开更多
生长停滞特异性蛋白6(growth arrest specific protein 6,GAS6)在肿瘤发生发展中发挥重要作用,其信号转导参与细胞增殖、黏附与迁移,但它在子宫内膜异位症(endometriosis, EMs)的相关功能及分子机制尚不明确。本研究从GEO数据库检索并...生长停滞特异性蛋白6(growth arrest specific protein 6,GAS6)在肿瘤发生发展中发挥重要作用,其信号转导参与细胞增殖、黏附与迁移,但它在子宫内膜异位症(endometriosis, EMs)的相关功能及分子机制尚不明确。本研究从GEO数据库检索并下载子宫内膜异位症相关转录物组数据集,并对其进行GEO在线分析,筛选差异表达基因并进行GO聚类和KEGG通路富集分析。利用10例无内异症且无明确疾病妇女的在位子宫内膜,以及11例卵巢巧克力囊肿病人异位子宫内膜,对3个以上数据集共有的差异基因的mRNA水平进行实时荧光定量PCR验证。在子宫内膜异位症临床样本中,采用免疫组化、实时荧光定量PCR验证关键调控因子GAS6及上皮间充质转化(epithelial mesenchymal transition, EMT)标记基因的表达水平,并利用免疫荧光对GAS6和E-钙黏着蛋白(E-cadherin)进行共标。研究发现:从4个转录物组数据集中共筛选出47个差异表达基因,其主要富集于细胞迁移等过程以及MAPK、PI3K-AKT、紧密连接等相关信号通路。3个以上数据集所共有的9个差异基因在子宫内膜异位症病人中的mRNA水平均符合生物信息学分析的结果。GAS6在子宫内膜异位症病人异位内膜中的表达水平高于对照组(P<0.05),并且子宫内膜异位症病人的内膜组织中存在EMT现象,EMT的标志物E-钙黏着蛋白表达水平下调(P<0.05)、波形蛋白(vimentin)表达水平上调(P<0.01)。在GAS6高表达的子宫内膜异位症患者异位子宫内膜腺上皮细胞中,E-cadherin显示低表达,提示GAS6可能在子宫内膜异位症中介导EMT过程。综上所述,本研究初步揭示GAS6在子宫内膜异位症病人中高表达,及其可能介导EMT过程参与子宫内膜异位症的发生与发展,为子宫内膜异位症的临床治疗提供潜在靶标。展开更多
基金Supported by the National Natural Science Foundation of China,No.81702777Natural Science Foundation of Guangdong Province,No.2015A030310053
文摘BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in the liver,but is depleted in some tumor tissues.However,the functional mechanisms of GAS2 in hepatocellular carcinoma(HCC)are not fully defined.AIM To investigate the function and mechanism of GAS2 in HCC.METHODS GAS2 expression in clinic liver and HCC specimens was analyzed by real-time PCR and western blotting.Cell proliferation was analyzed by counting,MTS,and colony formation assays.Cell cycle analysis was performed by flow cytometry.Cell apoptosis was investigated by Annexin V apoptosis assay and western blotting.RESULTS GAS2 protein expression was lower in HCC than in normal tissues.Overexpression of GAS2 inhibited the proliferation of HCC cells with wide-type p53,while knockdown of GAS2 promoted the proliferation of hepatocytes(P<0.05).Furthermore,GAS2 overexpression impeded the G1-to-S cell cycle transition and arrested more G1 cells,particularly the elevation of sub G1(P<0.01).Apoptosis induced by GAS2 was dependent on p53,which was increased by etoposide addition.The expression of p53 and apoptosis markers was further enhanced when GAS2 was upregulated,but became diminished upon downregulation of GAS2.In the clinic specimen,GAS2 was downregulated in more than 60%of HCCs.The average fold changes of GAS2 expression in tumor tissues were significantly lower than those in paired non-tumor tissues(P<0.05).CONCLUSION GAS2 plays a vital role in HCC cell proliferation and apoptosis,possibly by regulating the cell cycle and p53-dependent apoptosis pathway.
文摘Objective To investigate the effect of interleukin-6(IL-6)on the human growth hormone(hGH)gene expression in a rat somatotropic pituitary cell line MtT/S.Methods The plasmids containing various lengths of hGH gene 5'-promoter fragments were constructed.Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1(+)with DMRIE-C transfection reagent.After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction pathways,the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism.Results The 103 U/mL IL-6 stimulated GH secretion and synthesis,and promoted the 5'-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control.Among inhibitors of signaling transduction pathways,mitogen-activated protein kinase kinase(MAPKK/MEK)inhibitor PD98059(40 μmol/L)and p38 mitogen-activated protein kinase(MAPK)inhibitor SB203580(5 μmol/L)completely blocked the stimulatory effect of IL-6.Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells.Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity.A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6.The results showed that the stimulatory effect of IL-6 was abolished following deletion of the-196 to-132 bp fragment.Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells.The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK,and a fragment of promoter sequence that spans the-196 to-132 bp of the gene,but may be unlinked with Pit-1 protein.
文摘生长停滞特异性蛋白6(growth arrest specific protein 6,GAS6)在肿瘤发生发展中发挥重要作用,其信号转导参与细胞增殖、黏附与迁移,但它在子宫内膜异位症(endometriosis, EMs)的相关功能及分子机制尚不明确。本研究从GEO数据库检索并下载子宫内膜异位症相关转录物组数据集,并对其进行GEO在线分析,筛选差异表达基因并进行GO聚类和KEGG通路富集分析。利用10例无内异症且无明确疾病妇女的在位子宫内膜,以及11例卵巢巧克力囊肿病人异位子宫内膜,对3个以上数据集共有的差异基因的mRNA水平进行实时荧光定量PCR验证。在子宫内膜异位症临床样本中,采用免疫组化、实时荧光定量PCR验证关键调控因子GAS6及上皮间充质转化(epithelial mesenchymal transition, EMT)标记基因的表达水平,并利用免疫荧光对GAS6和E-钙黏着蛋白(E-cadherin)进行共标。研究发现:从4个转录物组数据集中共筛选出47个差异表达基因,其主要富集于细胞迁移等过程以及MAPK、PI3K-AKT、紧密连接等相关信号通路。3个以上数据集所共有的9个差异基因在子宫内膜异位症病人中的mRNA水平均符合生物信息学分析的结果。GAS6在子宫内膜异位症病人异位内膜中的表达水平高于对照组(P<0.05),并且子宫内膜异位症病人的内膜组织中存在EMT现象,EMT的标志物E-钙黏着蛋白表达水平下调(P<0.05)、波形蛋白(vimentin)表达水平上调(P<0.01)。在GAS6高表达的子宫内膜异位症患者异位子宫内膜腺上皮细胞中,E-cadherin显示低表达,提示GAS6可能在子宫内膜异位症中介导EMT过程。综上所述,本研究初步揭示GAS6在子宫内膜异位症病人中高表达,及其可能介导EMT过程参与子宫内膜异位症的发生与发展,为子宫内膜异位症的临床治疗提供潜在靶标。
