3.Cytokine aptamers as therapeutic and diagnostic agents.
Xin-Rui YAN ; Xu-Wen GAO ; Zhi-Qing ZHANG
Chinese Journal of Biotechnology 2004;20(4):627-632
Aptamers are oligonucleotides derived from an in vitro evolution process called SELEX (Systematic Evolution of Ligands by Exponential Enrichment). Aptamers specially binding to targets could recognize and inhibit the function of targets. Using this method, many powerful antagonists of cytokines have been found. In order for these antagonists to work in animal models of disease and in humans, it is necessary to modify the aptamers. First of all, 2'-F, 2'-NH2 and 2'-CH3O modifications of nucleoside triphosphates could prolong half-lives in blood. Aptamers can be kept in the circulation from hours to days by conjugating them to higher molecular weight vehicles. After modified, conjugated aptamers are injected into animals, they inhibit physiological functions known to be associated with their target cytokines. Exhibiting binding characteristics comparable to or even better than monoclonal antibodies, these ligands can be used as detection probes, highly efficient inhibitors of protein function or specific competitors in high-throughput screening (HTS) assays. Recently several aptamers of cytokines have been characterized. Some of them have been used as diagnostic agent for the detection of target cytokines. The first aptamer that has proceeded to phase II clinical studies is NX-1838, an injectable angiogenesis inhibitor that can be potentially used to treat macular degeneration-induced blindness. Aptamers will be versatile tools that can greatly enhance the efficiency of modern diagnose and therapy development.
Cytokines
;
antagonists & inhibitors
;
High-Throughput Screening Assays
;
Humans
;
Oligonucleotides
;
therapeutic use
;
SELEX Aptamer Technique
;
Vascular Endothelial Growth Factor A
;
antagonists & inhibitors
5.Screening for inhibitor of vascular endothelial growth factor from random peptide library.
Jie WU ; Hongbin ZHANG ; Jie WANG ; Taicheng YANG ; Jiang XIAN ; Chuanhong YANG ; Wenling ZHENG ; Huipeng CHEN ; Qingming WANG
Chinese Journal of Oncology 2002;24(6):540-543
OBJECTIVETo screen for the inhibitor of vascular endothelial growth factor (VEGF) 165 from random peptide library.
METHODSPositive phage clones were rescued after two rounds of panning and competitive elution. Its affinity activity to KDR was monitored through ELISA, immunohistochemical method, Chicken CAM assay and MTT.
RESULTSFive specific binding positive target molecule phage clones were obtained which were able to bind to cells whose surface had high KDR, among which, clone 3 and 13 could effectively block the vascularization of the chorioallantoic membrane of chick embryo, but they were not inhibitive on the proliferation of high KDR expression cells.
CONCLUSIONThe peptides, being the inhibitors of VEGF, may be useful in the treatment of cancers.
Animals ; Binding Sites ; Endothelial Growth Factors ; antagonists & inhibitors ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Lymphokines ; antagonists & inhibitors ; metabolism ; Peptide Library ; Peptides ; pharmacology ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors
7.Inhibiting effect of vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotides on VEGF expression in U937 cell.
Yun-Jie TONG ; Min ZHANG ; Ping ZOU ; Rong GUO
Journal of Experimental Hematology 2004;12(2):151-153
To study the effect of VEGF fully phosporothioated antisense oligodeoxynucleotide (VEGF-ASODN) on VEGF expression in acute monocyte leukemic cell line U937 in vitro, U937 cells were incubated with VEGF-ASODN at concentrations of 10, 20 and 30 micro mol/L or scrambled sequence as compared with negative control. The expression of VEGF mRNA was measured by semi-quantitative RT-PCR. The expression of VEGF protein was measured by Western blot. The result showed that VEGF-ASODN had obviously inhibitive effect on expression of VEGF in U937 cell, as compared with scrambled sequence and negative control (P < 0.05). Scrambled sequence group had no significant difference compared with negative control group (P > 0.05). It is concluded that the expressions of VEGF mRNA and protein in leukemic cell line U937 are down-regulated by VEGF-ASODN.
Humans
;
Oligodeoxyribonucleotides, Antisense
;
pharmacology
;
RNA, Messenger
;
analysis
;
U937 Cells
;
Vascular Endothelial Growth Factor A
;
analysis
;
antagonists & inhibitors
;
genetics
8.Advances in Retinopathy of Prematurity.
Xiao Xuan XU ; Ya Jun WU ; Hong Yun WU ; Yu Xiang HU ; Yi CHENG ; Li YAN ; Jie RAO ; Na WU ; Xiao Rong WU
Acta Academiae Medicinae Sinicae 2019;41(2):261-266
Retinopathy of prematurity(ROP)is a pathological neovascularization with fibrotic changes in the fundus of premature infants.It is a major cause of preventable blindness in children in both developing and developed countries.Treatment of ROP has long been a hot research topic in ophthalmology and pediatrics.With a clearer knowledge of the pathogenesis of ROP,more basic and clinical studies have been carried out.The anti-vascular endothelial growth factor therapy and surgical treatment have become mature strategies,and a variety of therapeutic drugs including insulin-like growth factor-1,transforming growth factor-β,polyunsaturated fatty acids,and β-adrenergic receptor blockers have been developed.This article reviews the recent advances in ROP.
Child
;
Humans
;
Infant, Newborn
;
Infant, Premature
;
Neovascularization, Pathologic
;
therapy
;
Retinopathy of Prematurity
;
drug therapy
;
surgery
;
Vascular Endothelial Growth Factor A
;
antagonists & inhibitors
9.Retinopathy of prematurity: an epidemic in the making.
Graham E QUINN ; Clare GILBERT ; Brian A DARLOW ; Andrea ZIN
Chinese Medical Journal 2010;123(20):2929-2937
OBJECTIVETo explore the etiology, incidence and methods to prevent and treat severe retinopathy of prematurity (ROP), which is rapidly becoming a threat to the vision of babies in areas of the world where increasing numbers of premature babies are surviving.
DATA SOURCESThe data used in this review were mainly from Medline and PubMed published in English. The search term was "retinopathy of prematurity and premature birth".
STUDY SELECTIONWe discuss the historical perspectives, prevalence and incidence, classification and treatment methods of ROP in premature babies.
RESULTSPeripheral retinal ablation for eyes with severe ROP can help prevent progression to blindness and several large clinical trials have shown the effectiveness of this treatment in high risk eyes. As a greater proportion of VLBW and ELBW babies survive, the population of babies at risk increases. In various regions of the world, different identification criteria are used to determine which babies are at risk of blindness in order to provide timely diagnostic examinations and treatment as needed. Methods for preventing ROP include better ante-natal and obstetric care leading to a reduction in the rate of prematurity, the use of ante-natal corticosteroids, and better neonatal care practices. Recent developments have indicated that management of oxygen supplementation is important for the prevention of severe ROP; however, there is not yet known what oxygen saturation target should be adopted. Sepsis increases severe ROP in very preterm infants. Genetic associations and a telemedicine approach may be explored to detect ROP. Treatment of anti-VEGF therapy are potentially useful in eyes with severe ROP, but long term effects are not yet known and such treatment should be used with great caution.
CONCLUSIONSROP is a potentially binding disease for premature babies which is becoming more prevalent with the development improving neonatal services in many countries in recent years. High priority should be placed on developing approaches to prevent ROP blindness by reducing preterm birth, improving care of premature babies in neonatal care units, and providing adequate ophthalmological services in those regions.
Humans ; Incidence ; Infant, Newborn ; Insulin-Like Growth Factor I ; physiology ; Prevalence ; Retinopathy of Prematurity ; classification ; epidemiology ; prevention & control ; Sepsis ; complications ; Vascular Endothelial Growth Factor A ; antagonists & inhibitors
10.Perspectives of the Stomach Cancer Treatment: The Introduction of Molecular Targeted Therapy and the Hope for Cure.
Dae Young CHEUNG ; Jae Kwang KIM
The Korean Journal of Gastroenterology 2013;61(3):117-127
The overall survival of patients with gastric cancer has increased markedly in Korea, even higher than those of developed nations in Western world. It is due to the virtue of Korean National Cancer Screening Program and nowadays more than half of patients are diagnosed at the early stage of gastric cancer. However, for patients with unresectable gastric cancer, the outcomes of traditional cytotoxic chemotherapy regimens stay at a median survival of 9-11 months. The knowledge of cancer biology and the data from gene expression profiling has explosively expanded. Alternations in the expression of receptor tyrosine kinases pathways including Human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), phosphatydyl inositol 3 kinase/mammalian target of rapamycin (PI3K/mTOR), hepatocyte growth factor receptor (HGFR/MET), and fibroblast growth factor receptor (FGFR) were proved to be critical in cancer cell survival and biological agents targeting those altered receptor tyrosine kinases, their ligands and downstream effector molecules are developed for anti-cancer purpose. Until now, only trastuzumab succeeded to significantly increase overall survival of patients with HER2 overexpressing gastric cancer. Other agents including bevacizumab, gefitinib, erlotinib, and lapatinib failed to achieve the efficacy in survival gain over standard chemotherapy. Insights about the variations between regions, races, and individuals call for the effort to find reliable predictive biomarkers for drug efficacy and to design finely stratified clinical trials. Compared to current treatment paradigms, it is hoped that molecularly targeted treatment along with conventional cytotoxic chemotherapy will lead to significant gains in survival.
Antineoplastic Agents/*therapeutic use
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Biological Markers/*metabolism
;
Humans
;
Molecular Targeted Therapy
;
Receptor, Epidermal Growth Factor/antagonists & inhibitors/metabolism
;
Receptor, erbB-2/antagonists & inhibitors/metabolism
;
Stomach Neoplasms/*drug therapy/metabolism/pathology
;
Vascular Endothelial Growth Factor A/antagonists & inhibitors/metabolism