Recombinant proteins produced into yolk of genetically manipulated chickens are partly sialylated in N-glycan

The transgenic chicken is a candidate for the production of biopharmaceutical proteins with several economic superiorities. In general, the addition of sialic acid at the terminal of N-glycan is important for the bioactivity of biopharmaceuticals including plasma half-life; however, sialic acid has not been detected in the N-glycan of proteins produced in the egg white of genetically manipulated chickens. In this study, the extracellular domain of the TNF receptor and single chain Fv fused to Fc (referred to as TNFR/Fc and scFv/Fc, respectively) were purified from the egg yolk of genetically manipulated chickens and their sialylation in N-glycan was examined. In contrast to the glycan in egg white, yolk-derived proteins were partly sialylated. Lectin blot showed the existence of α2,6-sialic acid on TNFR/Fc, which disappeared with the removal of N-glycan by PNGase. In scFv/Fc, up to 7 % of N-glycan contained sialic acid. Disialyl glycans, which were detected in serum-derived scFv/Fc in a previous study, were not found in the yolk sample. Ovarian follicular tissue, which surrounds growing yolk, expressed several neuraminidases, suggesting the partial truncation of glycan during the yolk transfer process from the blood.     

Genetic transformation of Indian isolate of Lemna minor mediated by Agrobacterium tumefaciens and recovery of transgenic plants

Transgenic plants of an Indian isolate of Lemna minor have been developed for the first time using Agrobacterium tumefaciens and hard nodular cell masses ‘nodular calli’ developed on the BAP - pretreated daughter frond explants in B₅ medium containing sucrose (1.0 %) with 2,4-D (5.0 μM) and 2-iP (50.0 μM) or 2,4-D (50.0 μM) and TDZ (5.0 μM) under light conditions. These calli were co-cultured with A. tumefaciens strain EHA105 harboring a binary vector that contained genes for β-glucuronidase with intron and neomycin phosphortransferase. Transformed cells selected on kanamycin selection medium were regenerated into fronds whose transgenic nature was confirmed by histochemical assay for GUS activity, PCR analysis and Southern hybridization. The frequency of transformation obtained was 3.8 % and a period of 11–13 weeks was required from initiation of cultures from explants to fully grown transgenic fronds. The pretreatment of daughter fronds with BAP, use of non-ionic surfactant, presence of acetosyringone in co-cultivation medium, co-culture duration of 3 d and 16 h photoperiod during culture were found crucial for callus induction, frond regeneration and transformation of L. minor. This transformation system can be used for the production of pharmaceutically important protein and in bioremediation.     

Pioneer round of translation mediated by nuclear cap-binding proteins CBP80/20 occurs during prolonged hypoxia

Nonsense-mediated mRNA decay (NMD) is one of the mRNA surveillance mechanisms, which eliminates aberrant mRNAs harboring premature termination codons. NMD targets only mRNAs bound by the nuclear cap-binding protein complex CBP80/20 which directs the pioneer round of translation. Here we demonstrate that NMD occurs efficiently during prolonged hypoxia in which steady-state translation is drastically inhibited. Accordingly, CBP80 remains in the nucleus, and processing bodies are unaffected with regard to their abundance and number under prolonged hypoxic conditions. These results indicate that mRNAs enter the pioneer round of translation during prolonged hypoxia.     

Genomic analysis of genetic markers associated with inherited cardiomyopathy (round heart disease) in the turkey (Meleagris gallopavo)

In turkeys, spontaneous cardiomyopathy or round heart (RH) disease is characterised by dilated ventricles and cardiac muscle hypertrophy. Although the aetiology of RH is still unknown, the disease can have a significant economic impact on turkey producers. In an initial attempt to identify genomic regions associated with RH, we utilised the chicken genome sequence to target short DNA sequences (sequence-characterised amplified regions, SCARs) identified in previous studies that had significant differences in frequency distribution between RH+ and RH- turkeys. SCARs were comparatively aligned with the chicken whole-genome sequence to identify flanking regions for primer design. Primers from 32 alignments were tested and target sequences were successfully amplified for 30 loci (94%). Comparative re-sequencing identified putative SNPs in 20 of the 30 loci (67%). Genetically informative SNPs at 16 loci were genotyped in the UMN/NTBF turkey mapping population. As a result of this study, 34 markers were placed on the turkey/chicken comparative map and 15 markers were added to the turkey genetic linkage map. The position of these markers relative to cardiac-related genes is presented. In addition, analysis of genotypes at 109 microsatellite loci presumed to flank the SCAR sequences in the turkey genome identified four significant associations with RH.     

Pioneer round of translation occurs during serum starvation

The pioneer round of translation plays a role in translation initiation of newly spliced and exon junction complex (EJC)-bound mRNAs. Nuclear cap-binding protein complex CBP80/20 binds to those mRNAs at the 5'-end, recruiting translation initiation complex. As a consequence of the pioneer round of translation, the bound EJCs are dissociated from mRNAs and CBP80/20 is replaced by the cytoplasmic cap-binding protein eIF4E. Steady-state translation directed by eIF4E allows for an immediate and rapid response to changes in physiological conditions. Here, we show that nonsense-mediated mRNA decay (NMD), which restricts only to the pioneer round of translation but not to steady-state translation, efficiently occurs even during serum starvation, in which steady-state translation is drastically abolished. Accordingly, CBP80 remains in the nucleus and processing bodies are unaffected in their abundance and number in serum-starved conditions. These results suggest that mRNAs enter the pioneer round of translation during serum starvation and are targeted for NMD if they contain premature termination codons.     

三阴性乳腺癌术后辅助化疗方案的药学研究

目的:调查三阴性乳腺癌术后辅助化疗三种方案的临床应用情况,制订药学监护点。方法:收集我院2009年12月至2017年5月168例三阴性乳腺癌患者,化疗方案选用TAC、TP或AC→T方案,对三组患者进行具体分析。结果:胃肠道反应:TAC组Ⅰ度8例,Ⅱ度28例;AC→T组Ⅰ度4例,Ⅱ度100例;Ⅲ度4例;TP组Ⅱ度20例,Ⅲ度4例。骨髓抑制:TAC组Ⅱ度32例,Ⅲ度4例;AC→T组Ⅱ度92例,Ⅲ度16例;TP组Ⅱ度20例,Ⅲ度4例。三组不同化疗方案TNBC患者的胃肠道反应、骨髓抑制的发生情况比较差异均无统计学意义(P0.05)。一年肿瘤无进展生存率:TAC 88.9%;AC→T 92.6%;TP 100%,平均化疗费用:TAC20686.94±199.87元;AC→T 19470.83±150.988元;TP 12895.42±276.341元,平均住院天数为8.808±0.2792天;10.213±0.2429天;10.958±0.3782天。结论:在TAC、TP和AC→T方案中,TP方案治疗三阴性乳腺癌的临床疗效可,副反应少,费用少,是较优选的治疗方案。     

Examining the freezing process of an intermediate bulk containing an industrially relevant protein

Numerous biopharmaceuticals are produced in recombinant microorganisms in the controlled environment of a bioreactor, a process known as Upstream Process. To minimize product loss due to physico-chemical and enzymatic degradation, the Upstream Process should be directly followed by product purification, known as Downstream Process. However, the Downstream Process can be technologically complex and time-consuming which is why Upstream and Downstream Process usually have to be decoupled temporally and spatially. Consequently, the product obtained after the Upstream Process, known as intermediate bulk, has to be stored. In those circumstances, a freezing procedure is often performed to prevent product loss. However, the freezing process itself is inseparably linked to physico-chemical changes of the intermediate bulk which may in turn damage the product.The present study analysed the behaviour of a Tris-buffered intermediate bulk containing a biopharmaceutically relevant protein during a bottle freezing process. Major damaging mechanisms, like the spatiotemporal redistribution of ion concentrations and pH, and their influence on product stability were investigated. Summarizing, we show the complex events which happen in an intermediate bulk during freezing and explain the different causes for product loss.     

Cecropin A–melittin mutant with improved proteolytic stability and enhanced antimicrobial activity against bacteria and fungi associated with gastroenteritis in vitro

Cecropin A–melittin (CAM), a chimeric antimicrobial peptide with potent antimicrobial activity, is threatened by some special extracellular proteases when used to deal with certain drug-resistant pathogenic microbes in the gastrointestinal tract. Thus, a four-tryptophan-substitution mutant (CAM-W) from CAM was developed via the replacement of special amino acid residues to enhance the antimicrobial potency and to improve the proteolytic stability of this agent. The pharmaceutical index of CAM-W was investigated, with a focus on biological potency, cytotoxicity, and proteolytic stability, as well as pH and thermal resistance. CAM-W exhibited potent antimicrobial activity and was approximately 3–12 times higher than that of CAM. CAM-W also exhibited a strong antifungal activity against a series of common pathogenic fungi, in a lower IC50 range between 2.1 mg/L and 3.3 mg/L than that of its reference CAM ranging from 9.8 mg/L to 14.2 mg/L. Besides, CAM-W showed moderate cytotoxicity (IC₅₀ > 300 mg/L) in erythrocyte lysis test. In addition, CAM-W overcame challenges under various conditions, including specific temperatures (20, 30, 40, 50, 60, 70, 80, and 90 °C), pH values (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, and 9.0), and proteases (trypsin, pepsin, human neutrophil elastase, Pseudomonas aeruginosa elastase, and Staphylococcus aureus V8 protease) that are commonly present in human gastrointestinal tract. These results suggest that the four-tryptophan-substitution can confer CAM-W with a high pharmaceutical index, which is important for CAM-W to become a potential alternative to conventional antibiotics against bacteria and fungi associated with gastroenteritis.     

Round cell sarcomas – Biologically important refinements in subclassification

Round cell sarcomas are a heterogeneous group of tumors that often affect children and young adults and, if untreated, often pursue a very aggressive clinical course. Specific subtypes of round cell sarcoma, like Ewing sarcoma or rhabdomyosarcoma, respond to well-defined therapeutic regimens so that proper classification is crucial for appropriate patient management. A subset of round cell sarcomas, however, lack specific clinical, morphologic, and immunophenotypic features and cannot be unequivocally classified based on such features. Systematic application of cytogenetics and molecular genetic techniques has allowed for the identification of an increasing number of genetically defined subgroups within this category of undifferentiated tumors. Although the clinical relevance of these molecular categories is yet to be proven, the systematic identification of lesions that share reproducible biologic, and often morphologic and immunophenotypic features, has great impact in terms of biologic understanding and coherent classification schemes, and will help to guide the potential development of rational new therapies. In this review we discuss the main categories of undifferentiated round cell sarcoma, in relation to Ewing sarcoma and its molecular variants, with particular emphasis on the genetic and biologic features of recently described entities including desmoplastic small round cell tumor and CIC-DUX4 as well as BCOR-CCNB3-associated round cell sarcomas.This article is part of a Directed Issue entitled: Rare Cancers.