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21.
Erythropoietin is a major regulator of erythropoiesis which maintains the body's red blood cell mass and tissue oxygenation at an optimum level. Recombinant human erythropoietin (rhEPO), which is a widely used therapeutic agent for the treatment of anemia and which represents one of the largest biopharmaceuticals markets, is produced from recombinant Chinese hamster ovary cells. rhEPO is a glycoprotein with complex glycan structure, which is responsible for its therapeutic efficacy, including the in vivo activity and half-life. In order to obtain an optimal and consistent glycoform profile of rhEPO and concurrently maintain a high production yield, various approaches in drug development and cell culture technology have been attempted. Recent advances in rhEPO production are classified into three types: the development of improved rhEPO molecules by protein engineering; improvement of production host cells by genetic engineering; and culture condition optimization by fine control of the production mode/system, process parameters, and culture media. In this review, we focus on rhEPO production strategies as they have progressed thus far. Furthermore, the current status of the market and outlook on rhEPO and its derivatives are discussed. 相似文献
22.
Enhancement of hyperthermia-induced apoptosis by local anesthetics on human histiocytic lymphoma U937 cells 总被引:2,自引:0,他引:2
Arai Y Kondo T Tanabe K Zhao QL Li FJ Ogawa R Li M Kasuya M 《The Journal of biological chemistry》2002,277(21):18986-18993
The combined effects of hyperthermia at 44 degrees C and local anesthetics on apoptosis in human histiocytic lymphoma U937 cells were investigated. When the cells were exposed to hyperthermia for l0 min marginal DNA fragmentation and nuclear fragmentation were observed. In the presence of amide-type local anesthetics further enhancement was found depending on concentration. The order of the concentration required for maximum induction was the reverse order of the lipophilicity (prilocaine > lidocaine > bupivacaine). Western blotting revealed that in hyperthermia there was initial release of Ca(2+) from the intracellular store site as indicated by increased expression of the type 1 inositol-1,4,5-trisphosphate receptor. However, the combination with lidocaine did not induce any further enhancement. Lidocaine enhanced the decrease in ATP content and the increase in intracellular Ca(2+) concentration in individual cells induced by hyperthermia. In addition, superoxide formation, decrease in the mitochondrial membrane potential, and activation of intracellular caspase-3 were found in the cells treated with hyperthermia and lidocaine. All of these were suppressed in part in the presence of the intracellular Ca(2+) ion chelator BAPTA-AM (bis-(O-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl). The present results indicate that local anesthetics at optimal concentrations enhance hyperthermia-induced apoptosis via Ca(2+)- and mitochondria-dependent pathways. Initial release of Ca(2+) from intracellular store sites caused by hyperthermia and followed by the subsequent increase in the intracellular Ca(2+) concentration and the additional activation of the mitochondrial caspase-dependent pathway (partly regulated by intracellular Ca(2+) concentration) plays a crucial role in the enhancement of apoptosis induced by the combination of hyperthermia and lidocaine. 相似文献
23.
以聚丙烯酰胺凝胶电泳方法测定了331例辽宁满族新生儿脐带血血红蛋白F中Gγ/Aγ比值。结果显示:高Gγ(>80%)者4例,占1.21%,其基因频率(f)为0.00604,低Gγ(30-48%)者6例,占1.81%,其基因频率为0.00906,其余正常,Gγ平均值为65.23±6.38%。未发现AγT链。对其中八例异常者(4例高Gγ值,4例低Gγ值)的染色体DNA进行了基因图谱分析,确定4例高Gγ值者基因型有两种:Gγ-Gγ/Gγ-Aγ二例,Gγ-AGγ-Aγ/Gγ-Aγ二例;4例低Gγ值者基因型有二种,分别为:Aγ-Aγ/Gγ-Aγ二例和-GAγ/Gγ-Aγ二例。其中Aγ-Aγ基因型在中国人群中未见报道过。 相似文献
24.
25.
Lifang Guo Xingchao Geng Li Liu Yufa Miao Zhi Lin Min Yu Yan Fu Lihong Liu Bo Li Yongzhang Luo 《Journal of biochemical and molecular toxicology》2019,33(3)
Endostar, a potent endogenous antiangiogenic factor, is wildly used in clinics. However, it was easily degraded by enzymes and rapidly cleared by the kidneys. To overcome these shortcomings, PEGylated recombinant human endostatin was developed. In this study, the purity of M2ES was evaluated by silver stain and reversed‐phase high‐performance liquid chromatography. Ultraviolet spectrum was used to examine the structural of M2ES and endostar. The bioactivity and antitumor efficacy of M2ES were evaluated using an in vitro endothelial cell migration model and athymic nude mouse xenograft model of a heterogeneous lung adenocarcinoma, respectively. A preclinical study was performed to evaluate the acute toxicity and safety pharmacology in rhesus monkeys. The purity of M2ES was more than 98%; PEG modification has no effect on endostatin structure. Compared with the control group, M2ES dramatically retards endothelial cell migration and tumor growth. After intravenous (IV) infusions of M2ES at a dose level of three and 75 mg/kg in rhesus monkeys, there was no observable serious adverse event in both acute toxicity and safety pharmacology study. On the basis of the quality and bioactivity study data of M2ES and the absence of serious side effect in rhesus monkeys, M2ES was authorized to initiate a phase I clinical trial. 相似文献
26.
The islet beta cell-enriched MafA activator is a key regulator of insulin gene transcription 总被引:13,自引:0,他引:13
Zhao L Guo M Matsuoka TA Hagman DK Parazzoli SD Poitout V Stein R 《The Journal of biological chemistry》2005,280(12):11887-11894
27.
Min Lu Bin Liu Hui Xiong Fang Wu Chunhong Hu Ping Liu 《Journal of cellular and molecular medicine》2019,23(4):2431-2441
Despite initial dramatic efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR‐TKIs) in EGFR‐mutant lung cancer patients, subsequent emergence of acquired resistance is almost inevitable. Resveratrol and its derivatives have been found to exert some effects on EGFR‐TKI resistance in non‐small cell lung cancer (NSCLC), but the underlying mechanisms remain unclear. We screened several NSCLC cell lines with gefitinib resistance by MTT assay and analysed the miR‐345/miR‐498 expression levels. NSCLC cells were pre‐treated with a resveratrol derivative, trans‐3,5,4‐trimethoxystilbene (TMS) and subsequently challenged with gefitinib treatment. The changes in apoptosis and miR‐345/miR‐498 expression were analysed by flow cytometry and q‐PCR respectively. The functions of miR‐345/miR‐498 were verified by CCK‐8 assay, cell cycle analysis, dual‐luciferase reporter gene assay and immunoblotting analysis. Our results showed that the expression of miR‐345 and miR‐498 significantly decreased in gefitinib resistant NSCLC cells. TMS pre‐treatment significantly upregulated the expression of miR‐345 and miR‐498 increasing the sensitivity of NSCLC cells to gefitinib and inducing apoptosis. MiR‐345 and miR‐498 were verified to inhibit proliferation by cell cycle arrest and regulate the MAPK/c‐Fos and AKT/Bcl‐2 signalling pathways by directly targeting MAPK1 and PIK3R1 respectively. The combination of TMS and gefitinib promoted apoptosis also by miR‐345 and miR‐498 targeting the MAPK/c‐Fos and AKT/Bcl‐2 signalling pathways. Our study demonstrated that TMS reduced gefitinib resistance in NSCLCs via suppression of the MAPK/Akt/Bcl‐2 pathway by upregulation of miR‐345/498. These findings would lay the theoretical basis for the future study of TMS for the treatment of EGFR‐TKI resistance in NSCLCs. 相似文献
28.
29.
Fibronectin (FN) is the foremost proliferation‐associated extracellular matrix component promoting cell adhesion, migration, and survival. We examined the effect of FN on cell proliferation and the related signaling pathways in mouse embryonic stem (ES) cells. FN increased integrin β1, Src, focal adhesion kinase (FAK), and caveolin‐1 phosphorylation levels in a time‐dependent manner. Phosphorylation of Src, FAK, and caveolin‐1 was attenuated by integrin β1 neutralizing antibody. Integrin β1, Src, and FAK coimmunoprecipitated with caveolin‐1 in the presence of FN. In addition, FN increased RhoA and Rho kinase activation, which were completely blocked by PP2, FAK small interfering RNA (siRNA), caveolin‐1 siRNA, or the caveolar disruptor methyl‐β‐cyclodextrin (MβCD). FN also increased phosphorylation of Akt and ERK 1/2, which were significantly blocked by either FAK siRNA, caveolin‐1 siRNA, MβCD, GGTI‐286 (RhoA inhibitor), or Y‐27632 (Rho kinase inhibitor). FN‐induced increase of protooncogenes (c‐fos, c‐myc, and c‐Jun) and cell‐cycle regulatory proteins (cyclin D1/CDK4 and cyclin E/CDK2) expression levels were attenuated by FAK siRNA or caveolin‐1 siRNA. Furthermore, inhibition of each pathway such as integrin β1, Src, FAK, caveolin‐1, RhoA, Akt, and ERK 1/2 blocked FN‐induced [3H]‐thymidine incorporation. We conclude that FN stimulates mouse ES cell proliferation via RhoA‐PI3K/Akt‐ERK 1/2 pathway through caveolin‐1 phosphorylation. J. Cell. Physiol. 226: 267–275, 2010. © 2010 Wiley‐Liss, Inc. 相似文献