Molecular cloning of the porcine leukemia inhibitor factor（pLIF） has not been reported. A full-length eDNA encoding pLIF was cloned, expressed and characterized. The full-length porcine LIF cDNA encodes a 202 amino ...Molecular cloning of the porcine leukemia inhibitor factor（pLIF） has not been reported. A full-length eDNA encoding pLIF was cloned, expressed and characterized. The full-length porcine LIF cDNA encodes a 202 amino acid protein that has an 84% sequence identity to mouse LIF and 86% sequence identity to human LIF. The deduced amino acid sequence of a pLIF protein contains six conserved consensus N-linked glycosylation sites and six cysteine groups to form potential disulfide bonds. The pLIF was expressed in E coli, as a mature form, and in CHO cells as a secreted form. Both the forms of the recombinant pLIFs can maintain murine embryonic stem cells in an undifferentiated state in a culture. The recombinant pLiFs will be useful in establishing a long-term culture of stable pluripotent porcine embryonic stem cells for further manipulation.展开更多
【目的】研究NT3对早期卵泡存活、发育、激素合成的影响及其可能的作用机制,同时探讨NT3和LIF在早期卵泡启动发育方面是否存在协同或叠加效应。【方法】分离新生4d大鼠卵巢随机分配至新鲜组、基础培养组、NT3组、LIF组和NT3+LIF组,在37...【目的】研究NT3对早期卵泡存活、发育、激素合成的影响及其可能的作用机制,同时探讨NT3和LIF在早期卵泡启动发育方面是否存在协同或叠加效应。【方法】分离新生4d大鼠卵巢随机分配至新鲜组、基础培养组、NT3组、LIF组和NT3+LIF组,在37℃培养箱中培养14 d,经固定、包埋、切片后进行组织形态学、PCNA免疫组化、TUNEL凋亡分析,RTPCR检测KL m RNA表达及检测培养液中激素水平。【结果】相比新鲜组和基础培养组,NT3组、LIF组、NT3+LIF组中的始基卵泡比例下降,生长卵泡比例升高,同时PCNA蛋白表达显著增加;TUNEL分析显示NT3组、LIF组、NT3+LIF组的凋亡指数均显著降低;NT3、LIF组、NT3+LIF组卵巢中KL m RNA的表达量分别是对照组的(3.38±0.43)倍、(2.02±0.20)倍、(2.07±0.21)倍。【结论】NT3在早期卵泡存活、发育中有促进作用,上调KL基因表达可能是NT3的作用机制之一。NT3和LIF单独或相加均能促进卵泡发育,但两者之间无明显协同或叠加效应。展开更多
Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the d...Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL,SCR,platelet derived growth factor,vascular endothelial growth factor receptor and epidermal growth factor receptor families.Both multi-kinase inhibitors and singlekinase inhibitors have advantages and disadvantages,which are related to potential resistance mechanisms,pharmacokinetics,selectivity and tumor environment.In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist.Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor.Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity,while differences in gene expression exist between tumor and stromal cells.Considering these aspects,one type of inhibitor can generally not be preferred above the other,but will depend on the specific genetic constitution of the patient and the tumor,allowing personalized therapy.The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered(epi)genetics of the tumor.This strategy might result in treatment by a single multi kinase inhibitor for one patient,but in treatment by a couple of single kinase inhibitors for other patients.展开更多
LIF is a cytokine with leiotropic activities. In order to understand better the physiological and patho-physiological role of LIF. we have developed a simple and specific enzyme-linked immunosorbent assay (ELISAI for ...LIF is a cytokine with leiotropic activities. In order to understand better the physiological and patho-physiological role of LIF. we have developed a simple and specific enzyme-linked immunosorbent assay (ELISAI for detecting LIF in human plasma and serum and in tissue culture media. A monoclonal ami-LIF antibody 8B11 (IgGl) produced in our laboratory was coated onto microtiter plates. After block-展开更多
文摘Molecular cloning of the porcine leukemia inhibitor factor（pLIF） has not been reported. A full-length eDNA encoding pLIF was cloned, expressed and characterized. The full-length porcine LIF cDNA encodes a 202 amino acid protein that has an 84% sequence identity to mouse LIF and 86% sequence identity to human LIF. The deduced amino acid sequence of a pLIF protein contains six conserved consensus N-linked glycosylation sites and six cysteine groups to form potential disulfide bonds. The pLIF was expressed in E coli, as a mature form, and in CHO cells as a secreted form. Both the forms of the recombinant pLIFs can maintain murine embryonic stem cells in an undifferentiated state in a culture. The recombinant pLiFs will be useful in establishing a long-term culture of stable pluripotent porcine embryonic stem cells for further manipulation.
文摘【目的】研究NT3对早期卵泡存活、发育、激素合成的影响及其可能的作用机制,同时探讨NT3和LIF在早期卵泡启动发育方面是否存在协同或叠加效应。【方法】分离新生4d大鼠卵巢随机分配至新鲜组、基础培养组、NT3组、LIF组和NT3+LIF组,在37℃培养箱中培养14 d,经固定、包埋、切片后进行组织形态学、PCNA免疫组化、TUNEL凋亡分析,RTPCR检测KL m RNA表达及检测培养液中激素水平。【结果】相比新鲜组和基础培养组,NT3组、LIF组、NT3+LIF组中的始基卵泡比例下降,生长卵泡比例升高,同时PCNA蛋白表达显著增加;TUNEL分析显示NT3组、LIF组、NT3+LIF组的凋亡指数均显著降低;NT3、LIF组、NT3+LIF组卵巢中KL m RNA的表达量分别是对照组的(3.38±0.43)倍、(2.02±0.20)倍、(2.07±0.21)倍。【结论】NT3在早期卵泡存活、发育中有促进作用,上调KL基因表达可能是NT3的作用机制之一。NT3和LIF单独或相加均能促进卵泡发育,但两者之间无明显协同或叠加效应。
文摘Since in most tumors multiple signaling pathways are involved,many of the inhibitors in clinical development are designed to affect a wide range of targeted kinases.The most important tyrosine kinase families in the development of tyrosine kinase inhibitors are the ABL,SCR,platelet derived growth factor,vascular endothelial growth factor receptor and epidermal growth factor receptor families.Both multi-kinase inhibitors and singlekinase inhibitors have advantages and disadvantages,which are related to potential resistance mechanisms,pharmacokinetics,selectivity and tumor environment.In different malignancies various tyrosine kinases are mutated or overexpressed and several resistance mechanisms exist.Pharmacokinetics is influenced by interindividual differences and differs for two single targeted inhibitors or between patients treated by the same tyrosine kinase inhibitor.Different tyrosine kinase inhibitors have various mechanisms to achieve selectivity,while differences in gene expression exist between tumor and stromal cells.Considering these aspects,one type of inhibitor can generally not be preferred above the other,but will depend on the specific genetic constitution of the patient and the tumor,allowing personalized therapy.The most effective way of cancer treatment by using tyrosine kinase inhibitors is to consider each patient/tumor individually and to determine the strategy that specifically targets the consequences of altered(epi)genetics of the tumor.This strategy might result in treatment by a single multi kinase inhibitor for one patient,but in treatment by a couple of single kinase inhibitors for other patients.
文摘LIF is a cytokine with leiotropic activities. In order to understand better the physiological and patho-physiological role of LIF. we have developed a simple and specific enzyme-linked immunosorbent assay (ELISAI for detecting LIF in human plasma and serum and in tissue culture media. A monoclonal ami-LIF antibody 8B11 (IgGl) produced in our laboratory was coated onto microtiter plates. After block-
