Breast cancer resistance protein(BCRP)/ATP-binding cassette subfamily G member 2(ABCG2) is an ATP-binding cassette(ABC) transporter identified as a molecular cause of multidrug resistance(MDR) in diverse cancer cells....Breast cancer resistance protein(BCRP)/ATP-binding cassette subfamily G member 2(ABCG2) is an ATP-binding cassette(ABC) transporter identified as a molecular cause of multidrug resistance(MDR) in diverse cancer cells.BCRP physiologically functions as a part of a self-defense mechanism for the organism;it enhances elimination of toxic xenobiotic substances and harmful agents in the gut and biliary tract,as well as through the blood-brain,placental,and possibly blood-testis barriers.BCRP recognizes and transports numerous anticancer drugs including conventional chemotherapeutic and targeted small therapeutic molecules relatively new in clinical use.Thus,BCRP expression in cancer cells directly causes MDR by active efflux of anticancer drugs.Because BCRP is also known to be a stem cell marker,its expression in cancer cells could be a manifestation of metabolic and signaling pathways that confer multiple mechanisms of drug resistance,self-renewal(stemness),and invasiveness(aggressiveness),and thereby impart a poor prognosis.Therefore,blocking BCRP-mediated active efflux may provide a therapeutic benefit for cancers.Delineating the precise molecular mechanisms for BCRP gene expression may lead to identification of a novel molecular target to modulate BCRP-mediated MDR.Current evidence suggests that BCRP gene transcription is regulated by a number of trans-acting elements including hypoxia inducible factor 1α,estrogen receptor,and peroxisome proliferator-activated receptor.Furthermore,alternative promoter usage,demethylation of the BCRP promoter,and histone modification are likely associated with drug-induced BCRP overexpression in cancer cells.Finally,PI3K/AKT signaling may play a critical role in modulating BCRP function under a variety of conditions.These biological events seem involved in a complicated manner.Untangling the events would be an essential first step to developing a method to modulate BCRP function to aid patients with cancer.This review will present a synopsis of the impact of BCRP-mediated MDR in ca展开更多
Boron (B) is an essential nutrient for normal growth of higher plants, and B availability in soil and irrigation water is an important determinant of agricultural production. To date, a primordial function of B is u...Boron (B) is an essential nutrient for normal growth of higher plants, and B availability in soil and irrigation water is an important determinant of agricultural production. To date, a primordial function of B is undoubtedly its structural role in the ceil wall; however, there is increasing evidence for a possible role of B in other processes such as the maintenance of plasma membrane function and several metabolic pathways. In recent years, the knowledge of the molecular basis of B deficiency and toxicity responses in plants has advanced greatly. The aim of this review is to provide an update on recent findings related to these topics, which can contribute to a better understanding of the role of B in plants.展开更多
AIM: To investigate the single nucleotide polymorphism (SNPs) distribution of NOD2/CARD15 (R702W, G908R), OCTN1 1672CFT and OCTN2-207G/C in Chinese patients with inflammatory bowel disease (IBD). METHODS: A to...AIM: To investigate the single nucleotide polymorphism (SNPs) distribution of NOD2/CARD15 (R702W, G908R), OCTN1 1672CFT and OCTN2-207G/C in Chinese patients with inflammatory bowel disease (IBD). METHODS: A total of 61 patients with Crohn's disease (CD), 151 patients with ulcerative colitis (UC), and 200 unrelated healthy controls were genotyped. Genotyping was performed by sequence specific primer polymerase chain reaction (PCR-SSP) or by restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: Among the subjects in our study groups, including patients with CD, UC and healthy controls, none had OCTN and CARD15 variants and very rare IBD family history was found in our patients with the percentage of 0 (0/61 with CD) and 1.3% (2/151 with UC). CONCLUSION: Our results indicate that although OCTN or CARD15 variation is associated with susceptibility to IBD in Western populations, these might be rare and may not be associated with susceptibility to IBD in Chinese patients.展开更多
目的探讨慢传输型便秘(STC)与5-羟色胺转运体基因启动子区(5-HTTLPR)多态性的相关性。方法采用聚合酶链反应技术检测54例STC患者(STC组)和100例正常对照者5-羟色胺转运体基因启动子区多态性的分布频率。结果SIC组5-羟色胺转运体基因启...目的探讨慢传输型便秘(STC)与5-羟色胺转运体基因启动子区(5-HTTLPR)多态性的相关性。方法采用聚合酶链反应技术检测54例STC患者(STC组)和100例正常对照者5-羟色胺转运体基因启动子区多态性的分布频率。结果SIC组5-羟色胺转运体基因启动子区S/S基因型和S等位基因频率分别为72.2%、83.3%。对照组S/S基因型和S等位基因频率分别为50.0%、72.5%,两组间的差异有统计学意义(P<0.05)。STC组按性别、发病年龄(小于45岁和等于或超过45岁)分组后,比较5-HTTLPR基因多态性差异无统计学意义,但按结肠运输试验72 h后排出标志物是否达到40%分组后,未达到40%组S/S基因型频率明显高于达到组(71.7% vs 42.6%),差异有统计学意义(P<0.05)。结论5-HTTLPR的S/S型可能参与了慢传输型便秘的发病机制。展开更多
SWEETs (sugars will eventually be exported transporters) are a novel class of recently identified sugar transporters that play important roles in diverse physiological processes. However, only a few species of the p...SWEETs (sugars will eventually be exported transporters) are a novel class of recently identified sugar transporters that play important roles in diverse physiological processes. However, only a few species of the plant SWEETgene family have been functionally identified. Up till now, there has been no systematic analysis of the SWEETgene family in Cucurbitaceae crops. Here, a genome-wide characterization of this family was conducted in cucumber(Cucumis sativus L.). A total of 17 CsSWEETgenes were identified, which are not evenly distributed over the seven cucumber chromosomes. Cucumber SWEET protein sequences possess seven conserved domains and two putative serine phosphorylation sites. The phylo- genetic tree of the SWEET genes in cucumber, Arabidopsis thaliana, and Oryza sativa was constructed, and all the SWEET genes were divided into four clades. In addition, a number of putative cis-elements were identified in the promoter regions of these CsSWEET genes: nine types involved in phytohormone responses and eight types involved in stress responses. Moreover, the transcript levels of CsSWEETgenes were analyzed in various tissues using quantitative real-time polymerase chain reaction. A majority (70.58%) of the CsSWEET genes were confined to reproductive tissue development. Finally, 18 putative watermelon ClaSWEETgenes and 18 melon CmSWEETgenes were identified that showed a high degree of similarity with CsSWEETgenes. The results from this study provided a basic understanding of the CsSWEETgenes and may also facilitate future research to elucidate the function of SWEET genes in cucumber and other Cucurbitaceae crops.展开更多
为深入研究大肠杆菌谷胱甘肽转运系统的蛋白质结构和功能,对该系统中的gsiB基因进行了克隆和表达条件的优化。根据大肠杆菌谷胱甘肽转运系统中底物结合蛋白gsiB基因序列,利用PCR方法扩增到该基因的编码区序列,利用SLIC(Sequence and lig...为深入研究大肠杆菌谷胱甘肽转运系统的蛋白质结构和功能,对该系统中的gsiB基因进行了克隆和表达条件的优化。根据大肠杆菌谷胱甘肽转运系统中底物结合蛋白gsiB基因序列,利用PCR方法扩增到该基因的编码区序列,利用SLIC(Sequence and ligation–independent cloning)方法直接将其插入pWaldo-GFPe中,成功构建了重组表达质粒pWaldo-GFP-GsiB。将重组质粒转化不同的大肠杆菌表达菌株进行诱导表达,通过改变培养温度和IPTG浓度等条件,得到了能够大量表达目标蛋白的重组子。结果表明:大肠杆菌BL21(DE3)是gsiB基因表达的最佳宿主菌;18℃低温诱导培养有利于gsiB基因的大量表达;0.1mmol/LIPTG足够诱导gsiB基因表达,增加IPTG浓度(0.1mmol/L~1.0mmol/L)并不能明显地促进gsiB基因的表达。Western blotting结果显示目标蛋白质有表达,其分子量大小与预期相符。展开更多
文摘Breast cancer resistance protein(BCRP)/ATP-binding cassette subfamily G member 2(ABCG2) is an ATP-binding cassette(ABC) transporter identified as a molecular cause of multidrug resistance(MDR) in diverse cancer cells.BCRP physiologically functions as a part of a self-defense mechanism for the organism;it enhances elimination of toxic xenobiotic substances and harmful agents in the gut and biliary tract,as well as through the blood-brain,placental,and possibly blood-testis barriers.BCRP recognizes and transports numerous anticancer drugs including conventional chemotherapeutic and targeted small therapeutic molecules relatively new in clinical use.Thus,BCRP expression in cancer cells directly causes MDR by active efflux of anticancer drugs.Because BCRP is also known to be a stem cell marker,its expression in cancer cells could be a manifestation of metabolic and signaling pathways that confer multiple mechanisms of drug resistance,self-renewal(stemness),and invasiveness(aggressiveness),and thereby impart a poor prognosis.Therefore,blocking BCRP-mediated active efflux may provide a therapeutic benefit for cancers.Delineating the precise molecular mechanisms for BCRP gene expression may lead to identification of a novel molecular target to modulate BCRP-mediated MDR.Current evidence suggests that BCRP gene transcription is regulated by a number of trans-acting elements including hypoxia inducible factor 1α,estrogen receptor,and peroxisome proliferator-activated receptor.Furthermore,alternative promoter usage,demethylation of the BCRP promoter,and histone modification are likely associated with drug-induced BCRP overexpression in cancer cells.Finally,PI3K/AKT signaling may play a critical role in modulating BCRP function under a variety of conditions.These biological events seem involved in a complicated manner.Untangling the events would be an essential first step to developing a method to modulate BCRP function to aid patients with cancer.This review will present a synopsis of the impact of BCRP-mediated MDR in ca
基金Supported by Ministerio de Educación y Ciencia (D.G.I., BFU2006-05304)Junta de Andalucía (BIO-266), Spain.
文摘Boron (B) is an essential nutrient for normal growth of higher plants, and B availability in soil and irrigation water is an important determinant of agricultural production. To date, a primordial function of B is undoubtedly its structural role in the ceil wall; however, there is increasing evidence for a possible role of B in other processes such as the maintenance of plasma membrane function and several metabolic pathways. In recent years, the knowledge of the molecular basis of B deficiency and toxicity responses in plants has advanced greatly. The aim of this review is to provide an update on recent findings related to these topics, which can contribute to a better understanding of the role of B in plants.
基金Doctoral Natural Science Fund of Guangdong Province, China, No. 04300361
文摘AIM: To investigate the single nucleotide polymorphism (SNPs) distribution of NOD2/CARD15 (R702W, G908R), OCTN1 1672CFT and OCTN2-207G/C in Chinese patients with inflammatory bowel disease (IBD). METHODS: A total of 61 patients with Crohn's disease (CD), 151 patients with ulcerative colitis (UC), and 200 unrelated healthy controls were genotyped. Genotyping was performed by sequence specific primer polymerase chain reaction (PCR-SSP) or by restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: Among the subjects in our study groups, including patients with CD, UC and healthy controls, none had OCTN and CARD15 variants and very rare IBD family history was found in our patients with the percentage of 0 (0/61 with CD) and 1.3% (2/151 with UC). CONCLUSION: Our results indicate that although OCTN or CARD15 variation is associated with susceptibility to IBD in Western populations, these might be rare and may not be associated with susceptibility to IBD in Chinese patients.
文摘目的探讨慢传输型便秘(STC)与5-羟色胺转运体基因启动子区(5-HTTLPR)多态性的相关性。方法采用聚合酶链反应技术检测54例STC患者(STC组)和100例正常对照者5-羟色胺转运体基因启动子区多态性的分布频率。结果SIC组5-羟色胺转运体基因启动子区S/S基因型和S等位基因频率分别为72.2%、83.3%。对照组S/S基因型和S等位基因频率分别为50.0%、72.5%,两组间的差异有统计学意义(P<0.05)。STC组按性别、发病年龄(小于45岁和等于或超过45岁)分组后,比较5-HTTLPR基因多态性差异无统计学意义,但按结肠运输试验72 h后排出标志物是否达到40%分组后,未达到40%组S/S基因型频率明显高于达到组(71.7% vs 42.6%),差异有统计学意义(P<0.05)。结论5-HTTLPR的S/S型可能参与了慢传输型便秘的发病机制。
基金supported by the National Natural Science Foundation of China (31301792)the Beijing Natural Science Foundation, China (6142010)the Youth Scientific Research Funds of the Beijing Academy of Agriculture and Forestry Sciences, China (QNJJ201401)
文摘SWEETs (sugars will eventually be exported transporters) are a novel class of recently identified sugar transporters that play important roles in diverse physiological processes. However, only a few species of the plant SWEETgene family have been functionally identified. Up till now, there has been no systematic analysis of the SWEETgene family in Cucurbitaceae crops. Here, a genome-wide characterization of this family was conducted in cucumber(Cucumis sativus L.). A total of 17 CsSWEETgenes were identified, which are not evenly distributed over the seven cucumber chromosomes. Cucumber SWEET protein sequences possess seven conserved domains and two putative serine phosphorylation sites. The phylo- genetic tree of the SWEET genes in cucumber, Arabidopsis thaliana, and Oryza sativa was constructed, and all the SWEET genes were divided into four clades. In addition, a number of putative cis-elements were identified in the promoter regions of these CsSWEET genes: nine types involved in phytohormone responses and eight types involved in stress responses. Moreover, the transcript levels of CsSWEETgenes were analyzed in various tissues using quantitative real-time polymerase chain reaction. A majority (70.58%) of the CsSWEET genes were confined to reproductive tissue development. Finally, 18 putative watermelon ClaSWEETgenes and 18 melon CmSWEETgenes were identified that showed a high degree of similarity with CsSWEETgenes. The results from this study provided a basic understanding of the CsSWEETgenes and may also facilitate future research to elucidate the function of SWEET genes in cucumber and other Cucurbitaceae crops.
文摘为深入研究大肠杆菌谷胱甘肽转运系统的蛋白质结构和功能,对该系统中的gsiB基因进行了克隆和表达条件的优化。根据大肠杆菌谷胱甘肽转运系统中底物结合蛋白gsiB基因序列,利用PCR方法扩增到该基因的编码区序列,利用SLIC(Sequence and ligation–independent cloning)方法直接将其插入pWaldo-GFPe中,成功构建了重组表达质粒pWaldo-GFP-GsiB。将重组质粒转化不同的大肠杆菌表达菌株进行诱导表达,通过改变培养温度和IPTG浓度等条件,得到了能够大量表达目标蛋白的重组子。结果表明:大肠杆菌BL21(DE3)是gsiB基因表达的最佳宿主菌;18℃低温诱导培养有利于gsiB基因的大量表达;0.1mmol/LIPTG足够诱导gsiB基因表达,增加IPTG浓度(0.1mmol/L~1.0mmol/L)并不能明显地促进gsiB基因的表达。Western blotting结果显示目标蛋白质有表达,其分子量大小与预期相符。