目的:三阴性乳腺癌(triple-negative breast cancer,TNBC)具有耐药性强的特点,因此,患者会对临床上最常用的化疗药物紫杉醇敏感性降低,从而导致治疗效果不佳。谷氨酰胺合成酶(glutamine synthetase,GS)是合成谷氨酰胺所需的关键代谢酶,...目的:三阴性乳腺癌(triple-negative breast cancer,TNBC)具有耐药性强的特点,因此,患者会对临床上最常用的化疗药物紫杉醇敏感性降低,从而导致治疗效果不佳。谷氨酰胺合成酶(glutamine synthetase,GS)是合成谷氨酰胺所需的关键代谢酶,其高表达可诱导卵巢癌细胞对化疗药物降低敏感性。但是,GS是否影响TNBC细胞对紫杉醇的敏感性及其可能机制仍不清楚。本研究的目的是探讨GS是否影响TNBC细胞对紫杉醇的敏感性及其机制。方法:使用质粒转染和慢病毒感染分别构建过表达和敲低GS的TNBC细胞系。通过Western blot、细胞活力检测、克隆形成实验和细胞凋亡检测分析GS在TNBC细胞中对紫杉醇敏感性的影响。使用qRT-PCR检测过表达GS的细胞中药物代谢酶、药物转运蛋白、抗凋亡蛋白的表达。结果:GS在乳腺癌细胞中高表达,GS^(low)(MDA-MB-231)细胞对紫杉醇的敏感性高于GS^(high)(MDA-MB-468)细胞。过表达GS使TNBC细胞对紫杉醇的敏感性降低、克隆能力增强、抗凋亡能力增加,敲低GS可以增加紫杉醇对TNBC细胞的杀伤效果;过表达GS的TNBC细胞中,抗凋亡蛋白BAG3的表达显著升高。结论:在TNBC细胞中,高表达GS促进细胞增殖,使TNBC细胞凋亡减少,克隆形成能力增强;GS可能是通过上调BAG3的表达增强抗凋亡能力从而降低TNBC细胞对紫杉醇的敏感性。展开更多
Lodging in maize is one of the major problems in maize production worldwide,which causes serious yield and economic losses annually.By evaluating cultivar lodging resistance performance in target growing environments ...Lodging in maize is one of the major problems in maize production worldwide,which causes serious yield and economic losses annually.By evaluating cultivar lodging resistance performance in target growing environments before cultivar extension and application,the risks and losses can be significantly reduced.In this study,a GIS-based quantitative method for evaluating maize cultivar lodging resistance performance in target growing environments was established based on full cognition of environment stress,cultivar resistance,and the interaction between them.At first,comprehensive environment lodging stress is measured by three factors:1)extreme wind event in maize vegetative stage which is the direct factor,2)soil potassium content in target growing environment which is an indirect factor affecting corn stem sturdiness,and 3)planting density which is a human influence factor.Quantification methods of extreme probability analysis,spatial interpolation,normalization,and so on were used.Then,maize cultivar lodging resistance was determined using cumulative frequency distribution analysis of tested lodging data.At last,an evaluation matrix was established combining environment lodging stress and cultivar lodging resistance together,which was very simple and easy to understand method and the result is promising providing good direct support in practical cultivar application.The method used in this study,at county-level,cultivar-level and stress-level with GIS,can facilitate the identification of better-adapted growing environments for a specific maize cultivar,and provide direct support for maize cultivar recommendation and extension,so as to reduce the risk and loss of lodging in maize.It is more easy-operational and feasible than traditional surveying approach,especially for large-scale spatial trend analysis.So it is of both academic significance in accelerating precision agriculture development and practical significance in improving maize cultivar application.展开更多
文摘目的:三阴性乳腺癌(triple-negative breast cancer,TNBC)具有耐药性强的特点,因此,患者会对临床上最常用的化疗药物紫杉醇敏感性降低,从而导致治疗效果不佳。谷氨酰胺合成酶(glutamine synthetase,GS)是合成谷氨酰胺所需的关键代谢酶,其高表达可诱导卵巢癌细胞对化疗药物降低敏感性。但是,GS是否影响TNBC细胞对紫杉醇的敏感性及其可能机制仍不清楚。本研究的目的是探讨GS是否影响TNBC细胞对紫杉醇的敏感性及其机制。方法:使用质粒转染和慢病毒感染分别构建过表达和敲低GS的TNBC细胞系。通过Western blot、细胞活力检测、克隆形成实验和细胞凋亡检测分析GS在TNBC细胞中对紫杉醇敏感性的影响。使用qRT-PCR检测过表达GS的细胞中药物代谢酶、药物转运蛋白、抗凋亡蛋白的表达。结果:GS在乳腺癌细胞中高表达,GS^(low)(MDA-MB-231)细胞对紫杉醇的敏感性高于GS^(high)(MDA-MB-468)细胞。过表达GS使TNBC细胞对紫杉醇的敏感性降低、克隆能力增强、抗凋亡能力增加,敲低GS可以增加紫杉醇对TNBC细胞的杀伤效果;过表达GS的TNBC细胞中,抗凋亡蛋白BAG3的表达显著升高。结论:在TNBC细胞中,高表达GS促进细胞增殖,使TNBC细胞凋亡减少,克隆形成能力增强;GS可能是通过上调BAG3的表达增强抗凋亡能力从而降低TNBC细胞对紫杉醇的敏感性。
基金We acknowledge the China Meteorology Administration and the Beijing Jinsenonghua Seed Technology Co.,Ltd.for providing essential raw data for this study,and are very thankful that the study is funded by the National Natural Science Foundation of China(41301084)the Hunan Provincial Natural Science Foundation of China(13JJ6075)and the constructing program of the key discipline in Huaihua University.The authors are also very grateful to the anonymous reviewers who gave constructive comments and suggestions on this manuscript.
文摘Lodging in maize is one of the major problems in maize production worldwide,which causes serious yield and economic losses annually.By evaluating cultivar lodging resistance performance in target growing environments before cultivar extension and application,the risks and losses can be significantly reduced.In this study,a GIS-based quantitative method for evaluating maize cultivar lodging resistance performance in target growing environments was established based on full cognition of environment stress,cultivar resistance,and the interaction between them.At first,comprehensive environment lodging stress is measured by three factors:1)extreme wind event in maize vegetative stage which is the direct factor,2)soil potassium content in target growing environment which is an indirect factor affecting corn stem sturdiness,and 3)planting density which is a human influence factor.Quantification methods of extreme probability analysis,spatial interpolation,normalization,and so on were used.Then,maize cultivar lodging resistance was determined using cumulative frequency distribution analysis of tested lodging data.At last,an evaluation matrix was established combining environment lodging stress and cultivar lodging resistance together,which was very simple and easy to understand method and the result is promising providing good direct support in practical cultivar application.The method used in this study,at county-level,cultivar-level and stress-level with GIS,can facilitate the identification of better-adapted growing environments for a specific maize cultivar,and provide direct support for maize cultivar recommendation and extension,so as to reduce the risk and loss of lodging in maize.It is more easy-operational and feasible than traditional surveying approach,especially for large-scale spatial trend analysis.So it is of both academic significance in accelerating precision agriculture development and practical significance in improving maize cultivar application.
