Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds.) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precult...Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds.) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4-7 days and then co cultivated with Agrobacterium tumefaciens , LBA4404, which contains plasmid vector pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR). After 3 days of co cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4 D, 12-15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2-3 months of selection, the actively growing calli of 'Regent' and 'Tiger' were transferred to MS medium with 12-15 mg/L PPT and 250 mg/L cefotaxime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.展开更多
Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so th...Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.展开更多
Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two g...Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain （Vegfr△LBD） or the tyrosine kinase domain with an inactivation point mutation （Vegfr3^TKmat）. We show that lymphatic growth was disrupted in Vegfr3△LBD/△LBD and Vegfr3^TKmut3^TKmat mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3△LBD/△LBD but not Vegfr3^TKmut3^TKmat mice, lymph sac was present but there was lack of iym- phangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands （VEGF-C/-D） is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.展开更多
G protein-coupled receptors （GPCRs） play pivotal roles in regulating various cellular functions. It has been well established that GPCR activates NF-κB and aberrant regulation of GPCR-NF-κB signaling axis leads to...G protein-coupled receptors （GPCRs） play pivotal roles in regulating various cellular functions. It has been well established that GPCR activates NF-κB and aberrant regulation of GPCR-NF-κB signaling axis leads to cancers. However, how GPCRs induce NF-κB activation remains largely elusive. Recently, it has been shown that a novel scaffold protein, CARMA3, is indispensable in GPCR-induced NF-κB activation. In CARMA3-deficient mouse embryonic fibroblast cells, some GPCR ligand-, like lysophosphatidic acid （LPA）, induced NF-κB activation is completely abolished. Mechanistically, upon GPCR activation, CARMA3 is linked to the membrane by β-arrestin 2 and phosphorylated by some PKC isoform. Phosphorylation of CARMA3 unfolds its steric structure and recruits its downstream effectors, which in turn activate the IKK complex and NF-κB. Interestingly, GPCR （LPA）-CARMA3-NF-κB signaling axis also exists in ovarian cancer cells, and knockdown of CARMA3 results in attenuation of ovarian cancer migration and invasion, suggesting a novel target for cancer therapy. In this review, we summarize the biology of CARMA3, discuss the GPCR （LPA）-CARMA3-NF-κB signaling axis in ovarian cancer and speculate its potential role in other types of cancers. With a strongly increasing tendency to identify more LPA-like ligands, such as endothelin-1 and angiotensin II, which also activate NF-κB through CARMA3 and contribute to myriad diseases, GPCR-CARMA3-NF-κB signaling axis is emerging as a novel drug target for various types of cancer and other myriad diseases.展开更多
文摘Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds.) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4-7 days and then co cultivated with Agrobacterium tumefaciens , LBA4404, which contains plasmid vector pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR). After 3 days of co cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4 D, 12-15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2-3 months of selection, the actively growing calli of 'Regent' and 'Tiger' were transferred to MS medium with 12-15 mg/L PPT and 250 mg/L cefotaxime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.
文摘Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.
基金Acknowledgments We thank Dr Lena Claesson-Welsh （Uppsala University）, and PIs of Model Animal Research Center （MARC, Nanjing University） for the helpful discussion about the work, and Yanlan Cao, Wenting Shi and all the staff in the MARC Animal facility of Nanjing University for excellent technical assistance. This work wasfinancially supported by grants from the National Natural Science Foundation of China （30771069, 30671038, and 30930028）, the Ministry of Science and Technology of China （2006CB943500）, and the Ministry of Education of China （NCET： Program for New Century Excellent Talents in University）.
文摘Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain （Vegfr△LBD） or the tyrosine kinase domain with an inactivation point mutation （Vegfr3^TKmat）. We show that lymphatic growth was disrupted in Vegfr3△LBD/△LBD and Vegfr3^TKmut3^TKmat mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3△LBD/△LBD but not Vegfr3^TKmut3^TKmat mice, lymph sac was present but there was lack of iym- phangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands （VEGF-C/-D） is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.
文摘G protein-coupled receptors （GPCRs） play pivotal roles in regulating various cellular functions. It has been well established that GPCR activates NF-κB and aberrant regulation of GPCR-NF-κB signaling axis leads to cancers. However, how GPCRs induce NF-κB activation remains largely elusive. Recently, it has been shown that a novel scaffold protein, CARMA3, is indispensable in GPCR-induced NF-κB activation. In CARMA3-deficient mouse embryonic fibroblast cells, some GPCR ligand-, like lysophosphatidic acid （LPA）, induced NF-κB activation is completely abolished. Mechanistically, upon GPCR activation, CARMA3 is linked to the membrane by β-arrestin 2 and phosphorylated by some PKC isoform. Phosphorylation of CARMA3 unfolds its steric structure and recruits its downstream effectors, which in turn activate the IKK complex and NF-κB. Interestingly, GPCR （LPA）-CARMA3-NF-κB signaling axis also exists in ovarian cancer cells, and knockdown of CARMA3 results in attenuation of ovarian cancer migration and invasion, suggesting a novel target for cancer therapy. In this review, we summarize the biology of CARMA3, discuss the GPCR （LPA）-CARMA3-NF-κB signaling axis in ovarian cancer and speculate its potential role in other types of cancers. With a strongly increasing tendency to identify more LPA-like ligands, such as endothelin-1 and angiotensin II, which also activate NF-κB through CARMA3 and contribute to myriad diseases, GPCR-CARMA3-NF-κB signaling axis is emerging as a novel drug target for various types of cancer and other myriad diseases.
