BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have em...BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have emerges as crucial factors in the development and progression of multiple cancer types.We posit that PRMT1 and PRMT6 might interplay directly or in-directly in multiple ways accounting for shared disease phenotypes.AIM To investigate the mechanism of the interaction between PRMT1 and PRMT6.METHODS Gel electrophoresis autoradiography was performed to test the methyltranferase activity of PRMTs and characterize the kinetics parameters of PRMTs.Liquid chromatography-tandem mass spectrometryanalysis was performed to detect the PRMT6 methylation sites.RESULTS In this study we investigated the interaction between PRMT1 and PRMT6,and PRMT6 was shown to be a novel substrate of PRMT1.We identified specific arginine residues of PRMT6 that are methylated by PRMT1,with R106 being the major methylation site.Combined biochemical and cellular data showed that PRMT1 downregulates the enzymatic activity of PRMT6 in histone H3 methylation.CONCLUSION PRMT6 is methylated by PRMT1 and R106 is a major methylation site induced by PRMT1.PRMT1 methylation suppresses the activity of PRMT6.展开更多
Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PR...Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.展开更多
BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC)....BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC).Studies have shown that PD-L1 expression in tumors is an important indicator of the efficacy of immunotherapy.Tumor cells usually evade chemotherapy and host immune surveillance by epigenetic changes.Protein arginine methylation is a common posttranslational modification.Protein arginine methyltransferase(PRMT)1 is deregulated in a wide variety of cancer types,whose biological role in tumor immunity is undefined.AIM To investigate the combined effects and underlying mechanisms of anti-PD-L1 and type I PRMT inhibitor in pancreatic cancer in vivo.METHODS PT1001B is a novel type I PRMT inhibitor with strong activity and good selectivity.A mouse model of subcutaneous Panc02-derived tumors was used to evaluate drug efficacy,toxic and side effects,and tumor growth in vivo.By flow cytometry,we determined the expression of key immune checkpoint proteins,detected the apoptosis in tumor tissues,and analyzed the immune cells.Immunohistochemistry staining for cellular proliferation-associated nuclear protein Ki67,TUNEL assay,and PRMT1/PD-L1 immunofluorescence were used to elucidate the underlying molecular mechanism of the antitumor effect.RESULTS Cultured Panc02 cells did not express PD-L1 in vitro,but tumor cells derived from Panc02 transplanted tumors expressed PD-L1.The therapeutic efficacy of anti-PD-L1 mAb was significantly enhanced by the addition of PT1001B as measured by tumor volume(1054.00±61.37 mm3 vs 555.80±74.42 mm3,P<0.01)and tumor weight(0.83±0.06 g vs 0.38±0.02 g,P<0.05).PT1001B improved antitumor immunity by inhibiting PD-L1 expression on tumor cells(32.74%±5.89%vs 17.95%±1.92%,P<0.05).The combination therapy upregulated tumorinfiltrating CD8+T lymphocytes(23.75%±3.20%vs 73.34%±4.35%,P<0.01)and decreased PD-1+leukocytes(35.77%±3.30%vs 6.48%±1.08%,P<0.001)in tumor tissue compared to the control.In addition,PT1001B amplified the inhibitory effect of anti-PD-L1 on tumor cell proliferation and enhanced the induction of tumor cell apoptosis.PRMT1 downregulation was correlated with PD-L1 downregulation.CONCLUSION PT1001B enhances antitumor immunity and combining it with anti-PD-L1 checkpoint inhibitors provides a potential strategy to overcome anti-PD-L1 resistance in PDAC.展开更多
Background：Protein arginine methyltransferases 1 （PRMT1） is over-expressed in a variety of cancers,including lung cancer,and is correlated with a poor prognosis of tumor development.This study aimed to investigate ...Background：Protein arginine methyltransferases 1 （PRMT1） is over-expressed in a variety of cancers,including lung cancer,and is correlated with a poor prognosis of tumor development.This study aimed to investigate the role of PRMT1 in nonsmall cell lung cancer （NSCLC） migration in vitro.Methods：In this study,PRMT1 expression in the NSCLC cell line A549 was silenced using lentiviral vector-mediated short hairpin RNAs.Cell migration was measured using both scratch wound healing and transwell cell migration assays.The mRNA expression levels of matrix metalloproteinase 2 （MMP-2） and tissue inhibitor ofmetalloproteinase 1,2 （TIMP l,2） were measured using quantitative real-time reverse transcription-polymerase chain reaction.The expression levels of protein markers for epithelial-mesenchymal transition （EMT） （E-cadherin,N-cadherin）,focal adhesion kinase （FAK）,Src,AKT,and their corresponding phosphorylated states were detected by Western blot.Results：Cell migration was significantly inhibited in the PRMT1 silenced group compared to the control group.The mRNA expression of MMP-2 decreased while TIMP 1 and TIMP2 increased significantly.E-cadherin mRNA expression also increased while N-cadherin decreased.Only phosphorylated Src levels decreased in the silenced group while FAK or AKT remained unchanged.Conclusions：PRMT1-small hairpin RNA inhibits the migration abilities of NSCLC A549 cells by inhibiting EMT,extracellular matrix degradation,and Src phosphorylation in vitro.展开更多
[Objective] The aim of experiment was to lay molecular foundation for studying maturity mechanism of banana after harvest. [Method] The combined method of suppressing subtractive hybridization and cDNA micro-array wer...[Objective] The aim of experiment was to lay molecular foundation for studying maturity mechanism of banana after harvest. [Method] The combined method of suppressing subtractive hybridization and cDNA micro-array were used to obtain cDNA segment of one PRMT gene in banana and the whole cDNA sequence of the gene was cloned.The bioinformatics analysis was operated on it,in addition, the expression profile analysis was conducted in different organs and different mature periods of banana.[Result] The whole length of cDNA in MaPRMT1 was 1 158 bp and possessed a complete open reading frame,which could encode 385 amino acids.It had high homology with PRMT in plant,containing one Methyltransf_1 domain.The MaPRMT1 gene was expressed in root,stem,leaf and fruit of banana and the expression levels in stem and leaf were relatively high.As the increase of days after harvest,the expression level declined gradually,however it reached maximum when ethylene release was biggest,then it declined.[Conclusion] MaPRMT1 belonged to the first kind of arginine methyltransferase and it was expressed differently in different organs and fruits at different mature periods.展开更多
基金Supported by National Institutes of Health,No.5R01GM126154 and No.1R35GM149230。
文摘BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have emerges as crucial factors in the development and progression of multiple cancer types.We posit that PRMT1 and PRMT6 might interplay directly or in-directly in multiple ways accounting for shared disease phenotypes.AIM To investigate the mechanism of the interaction between PRMT1 and PRMT6.METHODS Gel electrophoresis autoradiography was performed to test the methyltranferase activity of PRMTs and characterize the kinetics parameters of PRMTs.Liquid chromatography-tandem mass spectrometryanalysis was performed to detect the PRMT6 methylation sites.RESULTS In this study we investigated the interaction between PRMT1 and PRMT6,and PRMT6 was shown to be a novel substrate of PRMT1.We identified specific arginine residues of PRMT6 that are methylated by PRMT1,with R106 being the major methylation site.Combined biochemical and cellular data showed that PRMT1 downregulates the enzymatic activity of PRMT6 in histone H3 methylation.CONCLUSION PRMT6 is methylated by PRMT1 and R106 is a major methylation site induced by PRMT1.PRMT1 methylation suppresses the activity of PRMT6.
基金Supported by National Natural Science Foundation of China(30825023)
文摘Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.
基金Supported by the National Natural Science Foundation of China,No. 81472844
文摘BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC).Studies have shown that PD-L1 expression in tumors is an important indicator of the efficacy of immunotherapy.Tumor cells usually evade chemotherapy and host immune surveillance by epigenetic changes.Protein arginine methylation is a common posttranslational modification.Protein arginine methyltransferase(PRMT)1 is deregulated in a wide variety of cancer types,whose biological role in tumor immunity is undefined.AIM To investigate the combined effects and underlying mechanisms of anti-PD-L1 and type I PRMT inhibitor in pancreatic cancer in vivo.METHODS PT1001B is a novel type I PRMT inhibitor with strong activity and good selectivity.A mouse model of subcutaneous Panc02-derived tumors was used to evaluate drug efficacy,toxic and side effects,and tumor growth in vivo.By flow cytometry,we determined the expression of key immune checkpoint proteins,detected the apoptosis in tumor tissues,and analyzed the immune cells.Immunohistochemistry staining for cellular proliferation-associated nuclear protein Ki67,TUNEL assay,and PRMT1/PD-L1 immunofluorescence were used to elucidate the underlying molecular mechanism of the antitumor effect.RESULTS Cultured Panc02 cells did not express PD-L1 in vitro,but tumor cells derived from Panc02 transplanted tumors expressed PD-L1.The therapeutic efficacy of anti-PD-L1 mAb was significantly enhanced by the addition of PT1001B as measured by tumor volume(1054.00±61.37 mm3 vs 555.80±74.42 mm3,P<0.01)and tumor weight(0.83±0.06 g vs 0.38±0.02 g,P<0.05).PT1001B improved antitumor immunity by inhibiting PD-L1 expression on tumor cells(32.74%±5.89%vs 17.95%±1.92%,P<0.05).The combination therapy upregulated tumorinfiltrating CD8+T lymphocytes(23.75%±3.20%vs 73.34%±4.35%,P<0.01)and decreased PD-1+leukocytes(35.77%±3.30%vs 6.48%±1.08%,P<0.001)in tumor tissue compared to the control.In addition,PT1001B amplified the inhibitory effect of anti-PD-L1 on tumor cell proliferation and enhanced the induction of tumor cell apoptosis.PRMT1 downregulation was correlated with PD-L1 downregulation.CONCLUSION PT1001B enhances antitumor immunity and combining it with anti-PD-L1 checkpoint inhibitors provides a potential strategy to overcome anti-PD-L1 resistance in PDAC.
基金This study was supported by grants from the Natural Science Foundation of Huzhou City，the Public Welfare Technical Applied Research Project of Huzhou City （No.2013GY 19 No.2013（3Z14）.Conflict of Interest：None declared
文摘Background：Protein arginine methyltransferases 1 （PRMT1） is over-expressed in a variety of cancers,including lung cancer,and is correlated with a poor prognosis of tumor development.This study aimed to investigate the role of PRMT1 in nonsmall cell lung cancer （NSCLC） migration in vitro.Methods：In this study,PRMT1 expression in the NSCLC cell line A549 was silenced using lentiviral vector-mediated short hairpin RNAs.Cell migration was measured using both scratch wound healing and transwell cell migration assays.The mRNA expression levels of matrix metalloproteinase 2 （MMP-2） and tissue inhibitor ofmetalloproteinase 1,2 （TIMP l,2） were measured using quantitative real-time reverse transcription-polymerase chain reaction.The expression levels of protein markers for epithelial-mesenchymal transition （EMT） （E-cadherin,N-cadherin）,focal adhesion kinase （FAK）,Src,AKT,and their corresponding phosphorylated states were detected by Western blot.Results：Cell migration was significantly inhibited in the PRMT1 silenced group compared to the control group.The mRNA expression of MMP-2 decreased while TIMP 1 and TIMP2 increased significantly.E-cadherin mRNA expression also increased while N-cadherin decreased.Only phosphorylated Src levels decreased in the silenced group while FAK or AKT remained unchanged.Conclusions：PRMT1-small hairpin RNA inhibits the migration abilities of NSCLC A549 cells by inhibiting EMT,extracellular matrix degradation,and Src phosphorylation in vitro.
文摘[Objective] The aim of experiment was to lay molecular foundation for studying maturity mechanism of banana after harvest. [Method] The combined method of suppressing subtractive hybridization and cDNA micro-array were used to obtain cDNA segment of one PRMT gene in banana and the whole cDNA sequence of the gene was cloned.The bioinformatics analysis was operated on it,in addition, the expression profile analysis was conducted in different organs and different mature periods of banana.[Result] The whole length of cDNA in MaPRMT1 was 1 158 bp and possessed a complete open reading frame,which could encode 385 amino acids.It had high homology with PRMT in plant,containing one Methyltransf_1 domain.The MaPRMT1 gene was expressed in root,stem,leaf and fruit of banana and the expression levels in stem and leaf were relatively high.As the increase of days after harvest,the expression level declined gradually,however it reached maximum when ethylene release was biggest,then it declined.[Conclusion] MaPRMT1 belonged to the first kind of arginine methyltransferase and it was expressed differently in different organs and fruits at different mature periods.
