AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 a...AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets which been found significant expression in our previous study.METHODS： Quantitative real-time polymerase chain reaction （qRT-PCR） was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 （LASP1） and Glutathione S Transferase pi （GST-Pi） were determined by qRT-PCR in mRNA level and western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice. RESULTS： Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference.CONCLUSION： These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma in future.展开更多
Tp53, a stress response gene, is involved in diverse cell death pathways and its activation is implicated in the pathogenesis of Parkinson＇s disease. However, whether the neuronal Tp53 protein plays a direct role in ...Tp53, a stress response gene, is involved in diverse cell death pathways and its activation is implicated in the pathogenesis of Parkinson＇s disease. However, whether the neuronal Tp53 protein plays a direct role in regulating dopaminergic （DA） neuronal cell death or neuronal terminal damage in different neurotoxicant models is unknown. In our recent studies, in contrast to the global inhibition of Tp53 function by phar- macological inhibitors and in traditional Tp53 knock-out mice, we examined the effects of DA-specific Tp53 gene deletion after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and methamphetamine exposure. Our data suggests that the Tp53 gene might be involved in both neuronal apoptosis and neuronal termi- nal damage caused by different neurotoxicants. Additional results from other studies also suggest that as a master regulator of many pathways that regulate apoptosis and synaptic terminal damage, it is possible that Tp53 may function as a signaling hub to integrate different signaling pathways to mediate distinctive target pathways. Tp53 protein as a signaling hub might be able to evaluate the microenvironment of neurons, assess the forms and severities of injury incurred, and determine whether apoptotic cell death or neuro- nal terminal degeneration occurs. Identification of the precise mechanisms activated in distinct neuronal damage caused by different forms and severities of injuries might allow for development of specific Tp53 inhibitors or ways to modulate distinct downstream target pathways involved.展开更多
Gynostemma(G.) pentaphyllum(Cucurbitaceae) contains various bioactive gypenosides. Ethanol extract from G. pentaphyllum(GP-EX) has been shown to have ameliorative effects on the death of dopaminergic neurons in animal...Gynostemma(G.) pentaphyllum(Cucurbitaceae) contains various bioactive gypenosides. Ethanol extract from G. pentaphyllum(GP-EX) has been shown to have ameliorative effects on the death of dopaminergic neurons in animal models of Parkinson’s disease(PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-and 6-hydroxydopamine. PD patients exhibit multiple symptoms, so PD-related research should combine neurotoxin models with genetic models. In the present study, we investigated the ameliorative effects of GP-EX, including gypenosides, on the cell death of dopaminergic neurons in the midbrain of A53 T α-synuclein transgenic mouse models of PD(A53 T). Both GP-EX and gypenosides at 50 mg/kg per day were orally administered to the A53 T mice for 20 weeks.α-Synuclein-immunopositive cells and α-synuclein phosphorylation were increased in the midbrain of A53 T mice, which was reduced following treatment with GP-EX. Treatment with GP-EX modulated the reduced phosphorylation of tyrosine hydroxylase, extracellular signal-regulated kinase(ERK1/2), Bcl-2-associated death promoter(Bad) at Ser112, and c-Jun N-terminal kinase(JNK1/2) due to α-synuclein overexpression. In the A53 T group, GP-EX treatment prolonged the latency of the step-through passive avoidance test and shortened the transfer latency of the elevated plus maze test. Gypenosides treatment exhibited the effects and efficacy similar to those of GP-EX. Taken together, GP-EX, including gypenosides, has ameliorative effects on dopaminergic neuronal cell death due to the overexpression of α-synuclein by modulating ERK1/2, Bad at Ser112, and JNK1/2 signaling in the midbrain of A53 T mouse model of PD. Further studies are needed to investigate GP-EX as a treatment for neurodegenerative synucleinopathies, including PD. This study was approved by the Animal Ethics Committee of Chungbuk National University(approval No. CBNUA-956-16-01) on September 21, 2016.展开更多
目的:验证G2/S期应答相关蛋白1(G2 and S phase-expressed protein 1,GTSE1)在原发性肝癌组织及细胞株中高表达,并探讨其表达下调对肝癌细胞凋亡的影响。方法:采用内置R程序对GEO(Gene Expression Omnibus)数据库中4项原发性肝癌临床研...目的:验证G2/S期应答相关蛋白1(G2 and S phase-expressed protein 1,GTSE1)在原发性肝癌组织及细胞株中高表达,并探讨其表达下调对肝癌细胞凋亡的影响。方法:采用内置R程序对GEO(Gene Expression Omnibus)数据库中4项原发性肝癌临床研究的基因表达矩阵数据进行分析,筛选肝癌与癌旁组织差异表达基因。采用蛋白质印迹法验证3例肝癌组织和3株肝癌细胞中GTSE1蛋白表达水平。向肝癌Hep-G2和Bel-7402细胞中分别转染GTSE1 siRNA后,采用CCK-8和FCM法分别检测GTSE1表达下调对肝癌细胞增殖、凋亡及5-氟尿嘧啶(5-fluorouracil,5-FU)敏感性的影响,进一步采用蛋白质印迹法检测p53含量及其亚细胞定位,以及Bcl-2家族成员的表达变化。结果:4项研究中原发性肝癌组织表达水平均上调和下调的基因分别为51和146个。其中,上调基因产物GTSE1蛋白在3例临床肝癌组织标本和3株肝癌细胞Hep-G2、Bel-7402和SMMC-7721中均得到进一步验证(P值均<0.001)。siRNA转染后,肝癌Hep-G2和Bel-7402细胞中GTSE1基因沉默效率>70%。与对照组相比,GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞增殖被明显抑制,并随着时间延长,抑制作用逐渐增强(P值均<0.05);GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞周期被阻滞在G1期,同时细胞凋亡率明显升高,且细胞对5-FU的敏感性明显增强(P值均<0.01)。GTSE1表达下调后的肝癌Hep-G2和Bel-7402细胞中总p53及磷酸化P53表达水平均明显上调(P值均<0.05),且细胞核内p53水平升高(P值均<0.01);Bcl-2家族促凋亡成员Bax和Bak表达水平均上调,而抗凋亡成员Bcl-2表达水平下调(P值均<0.05)。结论:下调肝癌中GTSE1蛋白表达能通过活化p53通路促进细胞凋亡,并增加肝癌细胞对化疗药物的敏感性。展开更多
Gain-of-function (GOF), the most malicious oncogenic activity of a cancer-promoting protein, is well illustrated to three hotspot p53 mutations at R248, R175, and R273 with distinct molecular mechanisms. Yet, less is ...Gain-of-function (GOF), the most malicious oncogenic activity of a cancer-promoting protein, is well illustrated to three hotspot p53 mutations at R248, R175, and R273 with distinct molecular mechanisms. Yet, less is known about another hotspot p53 mutant, R249S (p53-R249S). p53-R249S is the sole hotspot mutation in hepatocellular carcinoma (HCC) that is highly associated with chronic hepatitis B virus (HBV) infection and dietary exposure to aflatoxin B1 (AFB1). Its GOF is suggested by the facts that this mutant is associated with earlier onset of HCC and poorer prognosis of cancer patients and that its overexpression drives HCC proliferation and tumorigenesis. By contrast, simply knocking in this mutant in normal mice did not show apparent GOF activity. Hence, the GOF activity for p53-R249S and its underlying mechanisms have been elusive until recent findings offered some new insights. This review will discuss these findings as well as their clinical significance and implications for the development of a strategy to target multiple molecules as a therapy for p53-R249S-harboring HCC.展开更多
基金Supported by the National Natural Science Foundation of China (No.81570891 No.81272981)+3 种基金Beijing Natural Science Foundation (No.7151003)Advanced Health Care Professionals Development Project of Beijing Municipal Health Bureau (No.2014-2-003)the Capital Health Research and Development of Special (No.2016-1-2051)Hospitals’ Ascent Plan (No.DFL20150201)
文摘AIM： To reveal the insight mechanism of liver metastasis in uveal melanoma, we investigated cell functions of microRNA-21 in three different uveal melanoma cell lines and analyze the relationship of target gene p53 and its downstream targets which been found significant expression in our previous study.METHODS： Quantitative real-time polymerase chain reaction （qRT-PCR） was used to detect microRNA-21 expression in normal uveal tissue and uveal melanoma cell lines. Lenti-virus expression system was used to construct OCM-1, MuM-2B and M619 cell line with stable overexpression and inhibition of microRNA-21. In vitro cell function tests such as cell proliferation, cell apoptosis, cell circle and abilities of migration and invasion were examined by MTT, BrdU assay, flow cytometry, transwell assay and Matrigel invasion assay respectively. The target gene was predicted by bioinformatics and confirmed by using a dual luciferase reporter assay. The expression of p53 and its suspected downstream targets LIM and SH3 protein 1 （LASP1） and Glutathione S Transferase pi （GST-Pi） were determined by qRT-PCR in mRNA level and western blotting analysis in protein level. Finally, the effect of microRNA-21 in a xenograft tumor model was assessed in four-week-old BALB/c nude mice. RESULTS： Compared to normal uveal melanoma, expressions of microRNA-21 were significantly higher in uveal melanoma cell lines. Overexpression of microRNA-21 promoted proliferation, migration, and invasion of OCM-1, M619 and MuM-2B cells, while inhibition of microRNA-21 reveal opposite effects. Wild type p53 was identified as a target gene of microRNA-21-3p, and proved by dual luciferase reporter assay. Up-regulated microRNA-21 inhibited the expression of wild type p53 gene, and the increased expression of LASP1 in mRNA level and protein level, while down-regulated microRNA-21 presented opposite way. However, GST-pi showed the potential pattern as expected, but relative mRNA level showed no statistically significant difference in OCM-1 cells. Furthermore, the mRNA expression of GST-pi was decreased in microRNA-21 overexpressing MuM-2B, and increased in M619 cells with inhibition of microRNA-21. In vivo, inhibition of microRNA-21 reduced tumor growth with statistically significant difference.CONCLUSION： These findings provide novel insight into molecular etiology of microRNA-21 in uveal melanoma cell lines, and suggest that microRNA-21 might be a potential candidate for the diagnosis and prognostic factor of human uveal melanoma in future.
文摘Tp53, a stress response gene, is involved in diverse cell death pathways and its activation is implicated in the pathogenesis of Parkinson＇s disease. However, whether the neuronal Tp53 protein plays a direct role in regulating dopaminergic （DA） neuronal cell death or neuronal terminal damage in different neurotoxicant models is unknown. In our recent studies, in contrast to the global inhibition of Tp53 function by phar- macological inhibitors and in traditional Tp53 knock-out mice, we examined the effects of DA-specific Tp53 gene deletion after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and methamphetamine exposure. Our data suggests that the Tp53 gene might be involved in both neuronal apoptosis and neuronal termi- nal damage caused by different neurotoxicants. Additional results from other studies also suggest that as a master regulator of many pathways that regulate apoptosis and synaptic terminal damage, it is possible that Tp53 may function as a signaling hub to integrate different signaling pathways to mediate distinctive target pathways. Tp53 protein as a signaling hub might be able to evaluate the microenvironment of neurons, assess the forms and severities of injury incurred, and determine whether apoptotic cell death or neuro- nal terminal degeneration occurs. Identification of the precise mechanisms activated in distinct neuronal damage caused by different forms and severities of injuries might allow for development of specific Tp53 inhibitors or ways to modulate distinct downstream target pathways involved.
基金supported by the National Research Foundation of Korea,grant No.2016R1D1A3B03930722(to MKL),Republic of Korea
文摘Gynostemma(G.) pentaphyllum(Cucurbitaceae) contains various bioactive gypenosides. Ethanol extract from G. pentaphyllum(GP-EX) has been shown to have ameliorative effects on the death of dopaminergic neurons in animal models of Parkinson’s disease(PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-and 6-hydroxydopamine. PD patients exhibit multiple symptoms, so PD-related research should combine neurotoxin models with genetic models. In the present study, we investigated the ameliorative effects of GP-EX, including gypenosides, on the cell death of dopaminergic neurons in the midbrain of A53 T α-synuclein transgenic mouse models of PD(A53 T). Both GP-EX and gypenosides at 50 mg/kg per day were orally administered to the A53 T mice for 20 weeks.α-Synuclein-immunopositive cells and α-synuclein phosphorylation were increased in the midbrain of A53 T mice, which was reduced following treatment with GP-EX. Treatment with GP-EX modulated the reduced phosphorylation of tyrosine hydroxylase, extracellular signal-regulated kinase(ERK1/2), Bcl-2-associated death promoter(Bad) at Ser112, and c-Jun N-terminal kinase(JNK1/2) due to α-synuclein overexpression. In the A53 T group, GP-EX treatment prolonged the latency of the step-through passive avoidance test and shortened the transfer latency of the elevated plus maze test. Gypenosides treatment exhibited the effects and efficacy similar to those of GP-EX. Taken together, GP-EX, including gypenosides, has ameliorative effects on dopaminergic neuronal cell death due to the overexpression of α-synuclein by modulating ERK1/2, Bad at Ser112, and JNK1/2 signaling in the midbrain of A53 T mouse model of PD. Further studies are needed to investigate GP-EX as a treatment for neurodegenerative synucleinopathies, including PD. This study was approved by the Animal Ethics Committee of Chungbuk National University(approval No. CBNUA-956-16-01) on September 21, 2016.
文摘目的:验证G2/S期应答相关蛋白1(G2 and S phase-expressed protein 1,GTSE1)在原发性肝癌组织及细胞株中高表达,并探讨其表达下调对肝癌细胞凋亡的影响。方法:采用内置R程序对GEO(Gene Expression Omnibus)数据库中4项原发性肝癌临床研究的基因表达矩阵数据进行分析,筛选肝癌与癌旁组织差异表达基因。采用蛋白质印迹法验证3例肝癌组织和3株肝癌细胞中GTSE1蛋白表达水平。向肝癌Hep-G2和Bel-7402细胞中分别转染GTSE1 siRNA后,采用CCK-8和FCM法分别检测GTSE1表达下调对肝癌细胞增殖、凋亡及5-氟尿嘧啶(5-fluorouracil,5-FU)敏感性的影响,进一步采用蛋白质印迹法检测p53含量及其亚细胞定位,以及Bcl-2家族成员的表达变化。结果:4项研究中原发性肝癌组织表达水平均上调和下调的基因分别为51和146个。其中,上调基因产物GTSE1蛋白在3例临床肝癌组织标本和3株肝癌细胞Hep-G2、Bel-7402和SMMC-7721中均得到进一步验证(P值均<0.001)。siRNA转染后,肝癌Hep-G2和Bel-7402细胞中GTSE1基因沉默效率>70%。与对照组相比,GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞增殖被明显抑制,并随着时间延长,抑制作用逐渐增强(P值均<0.05);GTSE1表达下调后肝癌Hep-G2和Bel-7402细胞周期被阻滞在G1期,同时细胞凋亡率明显升高,且细胞对5-FU的敏感性明显增强(P值均<0.01)。GTSE1表达下调后的肝癌Hep-G2和Bel-7402细胞中总p53及磷酸化P53表达水平均明显上调(P值均<0.05),且细胞核内p53水平升高(P值均<0.01);Bcl-2家族促凋亡成员Bax和Bak表达水平均上调,而抗凋亡成员Bcl-2表达水平下调(P值均<0.05)。结论:下调肝癌中GTSE1蛋白表达能通过活化p53通路促进细胞凋亡,并增加肝癌细胞对化疗药物的敏感性。
文摘Gain-of-function (GOF), the most malicious oncogenic activity of a cancer-promoting protein, is well illustrated to three hotspot p53 mutations at R248, R175, and R273 with distinct molecular mechanisms. Yet, less is known about another hotspot p53 mutant, R249S (p53-R249S). p53-R249S is the sole hotspot mutation in hepatocellular carcinoma (HCC) that is highly associated with chronic hepatitis B virus (HBV) infection and dietary exposure to aflatoxin B1 (AFB1). Its GOF is suggested by the facts that this mutant is associated with earlier onset of HCC and poorer prognosis of cancer patients and that its overexpression drives HCC proliferation and tumorigenesis. By contrast, simply knocking in this mutant in normal mice did not show apparent GOF activity. Hence, the GOF activity for p53-R249S and its underlying mechanisms have been elusive until recent findings offered some new insights. This review will discuss these findings as well as their clinical significance and implications for the development of a strategy to target multiple molecules as a therapy for p53-R249S-harboring HCC.
