整合素αvβ_3拮抗剂-苯丁酸氮芥偶联毒素的合成及其体外抗肿瘤活性

目的合成整合素(Integrin)αvβ3拮抗剂-苯丁酸氮芥偶联毒素,并检测其体外抗肿瘤活性。方法化学合成In-tegrinαvβ3拮抗剂,并与苯丁酸氮芥通过酰胺键偶联,MTT法检测偶联毒素对人脐静脉内皮细胞ECV304和肝癌细胞HepG2的抑制作用。结果合成的偶联毒素经核磁共振和质谱分析鉴定,表明结构正确,纯度达90%以上,对HepG2细胞的抑制效果弱于苯丁酸氮芥,但对ECV304细胞的抑制特异性较好。结论Integrinαvβ3拮抗剂-苯丁酸氮芥偶联毒素可抑制HepG2和ECV304细胞的增殖,为癌症治疗提供了一个新途径。     

重组蓖麻毒素A链的表达及半乳糖修饰

目的表达重组蓖麻毒素A链(ricin toxin A,RTA),并进行半乳糖糖基化修饰。方法将重组质粒pET-28a-RTA转化E. coli BL21(DE3),经IPTG诱导表达重组蛋白RTA,通过镍离子亲和层析柱纯化包涵体,并复性。采用1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐[1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride,EDC]/N,N-羟基琥珀酰亚胺(N-hydroxysuccinimide,NHS)法对重组RTA进行半乳糖糖基化修饰,并对偶联反应温度(20、25、30和37℃)和半乳糖与RTA的投料比(100∶1、500∶1、1 000∶1、1 500∶1和2 000∶1)进行优化。结果 RTA蛋白相对分子质量约34 000,主要以包涵体形式表达,纯化复性后纯度大于90%。最适偶联反应温度为25℃,半乳糖与RTA最适投料比为1 000∶1。结论成功表达了RTA蛋白,并通过EDC/NHS法实现了半乳糖与RTA的偶联。     

T-2毒素人工抗原的制备

在蒸气浴条件下,T-2毒素与琥珀酸酐(HS)反应合成了T-2HS,薄层层析显示,目标半抗原合成成功;然后通过碳二亚胺法将半抗原与载体蛋白偶联制备人工抗原,采用紫外扫描及SDS-PAGE鉴定。结果显示,T-2HS能与牛血清白蛋白(BSA)和卵清蛋白(OVA)结合生成T-2毒素抗原。紫外扫描分析表明,T-2毒素与牛血清白蛋白的偶联比为6.66∶1、与卵清蛋白的偶联比为10.11∶1,表明此完全抗原能够用于免疫动物。为进一步制备T-2毒素抗体奠定了基础。     

抗肝癌hdsFv-hEDN重组免疫毒素的表达及生物学活性

目的制备对人肝癌细胞具有特异性杀伤活性的抗肝癌重组免疫毒素。方法利用大肠杆菌系统表达抗肝癌hdsFvhEDN基因重组免疫毒素。表达产物经NiNTA亲和层析纯化后,进行特异性杀伤活性检测。结果抗肝癌hdsFvhEDN重组免疫毒素以可溶性形式表达于大肠杆菌培养上清中,并获得有效纯化。ELISA法检测证实其具有与相应抗原特异性结合的活性。细胞毒试验表明对肝癌细胞具有杀伤作用,而对正常肝细胞无损伤。结论已成功地制备了具有特异性结合和杀伤活性的抗肝癌hdsFvhEDN基因重组免疫毒素,为其进一步应用奠定基础。     

氟虫腈为配基的亲和介质制备及鱼类GABA受体纯化

以琼脂糖凝胶(Sepharose)CL-6B为载体,衍生化的氟虫腈为亲和配基,制备亲和层析介质,对其进行FT-IR和XPS表征。用制备的亲和层析介质分离鱼类脑组织中的GABA(γ-氨基丁酸)受体,研究分离蛋白质的效率。结果表明,成功将氟虫腈作为配体偶联到亲和介质上,偶联量为36.68μmol/g胶;SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)显示两条蛋白质条带,其相对分子质量约为44 kD和55 kD。     

抗磷脂酰肌醇蛋白聚糖3抗体定点偶联药物的制备及其抗肿瘤活性评价

目的 通过杂交瘤技术获得抗磷脂酰肌醇蛋白聚糖3(glypican 3,GPC3)单克隆抗体,并制备抗体偶联药物(antibody-drug conjugate,ADC),评价ADC的抗肿瘤活性。方法 采用免疫雄性BALB/c小鼠的方式获得高亲和力抗GPC3单克隆抗体,采用ELISA、流式细胞术检测抗体对抗原的亲和力及在肿瘤细胞的内吞率;并通过定点偶联技术获得DAR(drug-to-antibody ratio)为2的ADC药物,细胞杀伤试验检测其对肝癌细胞HepG2和Hep3b的增殖抑制效果。结果 抗体16C8-8E6在蛋白水平有很高的亲和力,EC₅₀为2.51 ng/mL,细胞水平(高表达GPC3的稳转株4E1、Hep3b、HepG2)亲和力明显高于原研抗体GC33(t分别为14.9、13.0和12.9,P均<0.05),在高表达GPC3的稳转株4E1的荧光强度为20 542±107;内吞率优于原研抗体GC33,48 h内吞率达73.9%。16C8-8E6-ADC对肝癌细胞HepG2和Hep3b有一定的抑制增殖活性。结论 成功获得靶向GPC3的单克隆抗体,...     

RTA和RTA-KEEL/KDEL基因的表达及细胞毒性

目的构建蓖麻毒素A链(RTA)和RTA-KEEL/KDEL基因表达载体,并检测重组蛋白的细胞毒性作用。方法用PCR法从蓖麻毒素基因组中扩增出RTA及RTA-KEEL/KDEL基因,连接T载体,测序正确后,定向插入质粒pET-28a(+)中,构建重组表达质粒pET-28a-RTA和pET-28a-RTA-KEEL/KDEL,转化感受态E.coliBL21(DE3),IPTG诱导表达,并对表达产物进行鉴定。结果所表达的RTA及RTA-KEEL/KDEL非融合蛋白经SDS-PAGE分析,相对分子质量约为31000,Westernblot分析具有反应原性,MTS法检测,RTA-KEEL/KDEL对CHO细胞具有比RTA更强的杀伤作用。结论已成功构建RTA和RTA-KEEL/KDEL表达载体,表达的重组蛋白具有生物学活性。     

呋喃妥因代谢物AHD单克隆抗体的制备及鉴定

目的制备呋喃妥因代谢物AHD单克隆抗体,并进行鉴定。方法利用对羧基苯甲醛合成1-氨基乙内酰胺脲(AHD)的衍生物1-氨基乙内酰脲-4-羧苯基肟(4-CPAHD),通过活性脂法将4-CPAHD与牛血清白蛋白(BSA)和卵清蛋白(OVA)偶联,获得免疫抗原4-CPAHD-BSA和包被抗原4-CPAHD-OVA,采用紫外分光光度法检测偶联是否成功。将人工合成抗原4-CPAHD-BSA免疫BALB/c小鼠,通过杂交瘤技术将免疫小鼠脾脏细胞与Sp2/0骨髓瘤细胞融合,筛选能稳定产生抗体的细胞株;通过间接ELISA法检测该细胞株分泌的单克隆抗体的效价、邻硝基-PAHD(2-NPAHD)对单克隆抗体的半数抑制浓度(IC50),并分析抗体的特异性。结果偶联后4-CPAHD-BSA的最大吸收峰有较明显的偏移,表明4-CPAHD与BSA偶联成功,平均偶联比为17.4∶1。制备的单克隆抗体的效价为1∶64 000,2-NPAHD对单克隆抗体的IC50为1.45μg/L,单克隆抗体与同类抗生素及其代谢物无交叉反应。结论制备的AHD单克隆抗体各项指标均较好,为呋喃妥因代谢物免疫检测试剂的研发奠定了基础。     

大黄酸衍生物的设计、合成及其抗肿瘤活性

以大黄酸为原料,通过不同的连接基团,将其与生物素、叶酸偶联得到10个目标化合物,其结构经~1 H NMR、MRR、MS确证。采用噻唑蓝(MTT)比色法测试目标化合物对肝癌细胞HepG2的体外增殖抑制活性,结果显示,所合成的10个目标化合物抑制HepG2细胞的活性优于大黄酸,且大多数化合物的活性强于阳性对照药氟尿嘧啶(5-FU)。     

氧化型低密度脂蛋白的制备及其对血管平滑肌细胞增殖能力的影响

目的制备氧化型低密度脂蛋白(ox-LDL),并检测其对血管平滑肌细胞(SMC)增殖能力的影响。方法肝素沉淀法提取LDL,Cu2+氧化法制备ox-LDL,MTT法测定其对Wistar大鼠血管SMC增殖能力的影响。结果LDL完全被氧化成ox-LDL SDS-PAGE显示,LDL相对分子质量降低;200mg/Lox-LDL可刺激体外培养的SMC增殖能力明显增强;ox-LDL浓度不低于600mg/L时,SMC增殖能力明显下降。结论成功制备了ox-LDL,一定浓度的ox-LDL可促进SMCs的增殖。     

人源化抗表皮生长因子受体单克隆抗体质控方法的建立

目的建立人源化抗表皮生长因子受体(Epithelial growth factor receptor,EGFR)单克隆抗体的质控方法。方法采用体外细胞生长抑制试验测定人源化抗EGFR单抗的生物学活性;质谱法和还原型SDS-PAGE法测定其准确相对分子质量;去封闭后用Edman降解法测定其N-末端氨基酸序列;SDS-PAGE和分子排阻高效液相色谱(SEC-HPLC)法测定其纯度;反向液相色谱(RP-HPLC)法测定其肽图;定量PCR法和狭缝杂交法测定其外源性DNA残留量;其余项目按《中国药典》三部(2010版)要求进行。结果人源化抗EGFR单抗原液和成品的相对生物学活性分别为(100±20)%和(94±14)%;质谱法测得该单抗参考品轻、重链的相对分子质量分别为23 370.75和50 341.00,相对误差分别为0.005%和0.006%;还原型SDS-PAGE测得该单抗轻、重链的相对分子质量为27 000和53 400;轻、重链N-末端氨基酸序列均与理论一致;单抗原液的还原型SDS-PAGE纯度为98.5%;SEC-HPLC原液纯度为(98.39±0.05)%和成品SEC-HPLC纯度为(98.17±0.04)%;肽图图谱与理化参考品一致;定量PCR测得其外源DNA残留量小于100 pg/剂量;其他各项指标均符合《中国药典》三部(2010版)要求及其他相关要求。结论初步建立了人源化抗表皮生长因子受体单克隆抗体的质控方法,可用于该制品的常规质量控制。     

Interesterification of tallow and sunflower oil

The objective of this study was to manufacture a shortening using chemical interesterification (IT) of tallow-sunflower oil blends to replace fish oil in the present formulation, which is now in short supply in Chile. The significant variables of the IT process were obtained by 2⁴⁻¹ fractional factorial design. The proportion of tallow (T) in the blend, catalyst concentration, and reaction temperature had a significant effect on the melting point (mp) (P≤0.05). IT of tallow and sunflower oil blends (90∶10 and 70∶30) diminished the mp, dropping point, and refractive index compared to tallow. However, a noninteresterified 90∶10 blend mp was not significantly different from tallow. IT produced a solid fat content (SFC) profile of IT90∶10 blend that was appropriate for use in shortenings for the baking industry. Blending and IT of the 90∶10 blend increased the melting profile of the tallow and the melting range from −40 to 60°C while the endotherms of the middle-melting triacylglycerols (TAG) decreased. The IT90∶10 blend hardnesswas 70% lower than tallow hardness, and the crystal network was composed of large spherulites in a network. IT resulted in an appropriate method to improve physical properties of tallow, whereas blending did not significantly modify it. The interesterification changed the SFC profile of IT90∶10, giving a more appropriate shortening for use in the baking industry.     

Targeting an EGFR Water Network with 4-Anilinoquin(az)oline Inhibitors for Chordoma

Quinoline- and quinazoline-based kinase inhibitors of the epidermal growth factor receptor (EGFR) have been used to target non-small cell lung cancer (NSCLC) and chordomas with varying amounts of success. We designed and prepared compounds to probe several key structural features including an interaction with Asp855 within the EGFR DGF motif and interactions with the active site water network. EGFR target engagement was then evaluated in a cellular assay, with the inhibitors then profiled in representative cellular models of NSCLC and chordomas. In addition, structure–activity relationship insight into EGFR inhibitor design with potent dimethoxyquin(az)olines identified compounds 1 [N-(3-ethynylphenyl)-6,7-dimethoxyquinolin-4-amine], 4 [N-(3-ethynylphenyl)-6,7-dimethoxyquinazolin-4-amine], and 7 [4-((3-ethynylphenyl)amino)-6,7-dimethoxyquinoline-3-carbonitrile]. We also identified 6,7-dimethoxy-N-(4-((4-methylbenzyl)oxy)phenyl)quinolin-4-amine (compound 18 ), which is the most potent inhibitor (IC₅₀=310 nm ) of the UCH-2 chordoma cell line to date.     

结核分枝杆菌复活促进因子E的原核表达及纯化

目的构建结核分枝杆菌复活促进因子E(RpfE)的原核表达质粒,在大肠杆菌中表达并纯化。方法采用PCR方法从结核分枝杆菌H37Rv基因组DNA中扩增出RpfE基因,双内切酶消化后,与同样酶消化的pET32a(+)载体连接,转化大肠杆菌Top10。阳性克隆经酶切和DNA测序鉴定正确后,将重组质粒转化至大肠杆菌BL21中,经IPTG诱导,由T7启动子调控表达RpfE蛋白,并对表达蛋白进行鉴定和纯化。结果双酶切鉴定所切下的片段大小与预期相符,测序结果与文献报道一致。经SDS-PAGE分析和Western blot鉴定,在相对分子质量41000处均可见特异性蛋白条带。经Ni2+-NTA金属螯合层析后,重组蛋白纯度可达90%以上。结论已成功地克隆并构建了RpfE基因的重组表达质粒pET32a(+)-RpfEv,并获得了高纯度的重组蛋白,为以后的深入研究奠定了基础。     

抗轮状病毒IgY和Fab'的分离与纯化

抗轮状病毒IgY可用两步盐析结合凝胶过滤从蛋黄中分离出来,用SDS—PAGE检测其纯度可达到95％以上。纯的IgY经胃蛋白酶分解得到的抗体片断（Fab’）,经SDS-PAGE和MALDI质谱法测定,其纯度达到99％以上。结果表明,所设计的分离抗轮状病毒IsY和Fab’的方法简单、有效。经ELISA法检测,Fab’的活性仍保持在IgY原始活性的70％以上。     

The Role of EREG/EGFR Pathway in Tumor Progression

Aberrant activation of the epidermal growth factor receptor (EGFR/ERBB1) by erythroblastic leukemia viral oncogene homolog (ERBB) ligands contributes to various tumor malignancies, including lung cancer and colorectal cancer (CRC). Epiregulin (EREG) is one of the EGFR ligands and is low expressed in most normal tissues. Elevated EREG in various cancers mainly activates EGFR signaling pathways and promotes cancer progression. Notably, a higher EREG expression level in CRC with wild-type Kirsten rat sarcoma viral oncogene homolog (KRAS) is related to better efficacy of therapeutic treatment. By contrast, the resistance of anti-EGFR therapy in CRC was driven by low EREG expression, aberrant genetic mutation and signal pathway alterations. Additionally, EREG overexpression in non-small cell lung cancer (NSCLC) is anticipated to be a therapeutic target for EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, recent findings indicate that EREG derived from macrophages promotes NSCLC cell resistance to EGFR-TKI treatment. The emerging events of EREG-mediated tumor promotion signals are generated by autocrine and paracrine loops that arise from tumor epithelial cells, fibroblasts, and macrophages in the tumor microenvironment (TME). The TME is a crucial element for the development of various cancer types and drug resistance. The regulation of EREG/EGFR pathways depends on distinct oncogenic driver mutations and cell contexts that allows specific pharmacological targeting alone or combinational treatment for tailored therapy. Novel strategies targeting EREG/EGFR, tumor-associated macrophages, and alternative activation oncoproteins are under development or undergoing clinical trials. In this review, we summarize the clinical outcomes of EREG expression and the interaction of this ligand in the TME. The EREG/EGFR pathway may be a potential target and may be combined with other driver mutation targets to combat specific cancers.     

表达HIV-1 Gag-Pol抗原的重组痘病毒的构建及免疫原性

目的构建稳定高效表达HIV-1Gag-Pol蛋白的重组痘病毒载体疫苗,并检测其体液免疫效果。方法将修饰型HIV-1Gag-Pol基因插入到痘病毒表达载体pSC11m2启动子P7·5下游,经与野生型痘病毒同源重组后,进行蓝白斑筛选。用筛选得到的重组病毒rM-GP转染HEK293细胞,经SDS-PAGE和Westernblot检测表达蛋白。用该重组病毒免疫BALB/c小鼠,并检测体液免疫应答。结果已筛选到稳定高效表达HIV-1Gag-Pol蛋白的重组痘病毒载体rM-GP,经Westernblot,在免疫小鼠血清中检测到抗HIV-1p24蛋白的特异性抗体。结论重组痘病毒载体rM-GP能稳定高效表达HIV-1Gag-Pol蛋白,并能引起有效的体液免疫应答。     

Aryl Hydrocarbon Receptor Defect Attenuates Mitogen-Activated Signaling through Leucine-Rich Repeats and Immunoglobulin-like Domains 1 (LRIG1)-Dependent EGFR Degradation

Aryl hydrocarbon receptor (AHR) genomic pathway has been well-characterized in a number of respiratory diseases. In addition, the cytoplasmic AHR protein may act as an adaptor of E3 ubiquitin ligase. In this study, the physiological functions of AHR that regulate cell proliferation were explored using the CRISPR/Cas9 system. The doubling-time of the AHR-KO clones of A549 and BEAS-2B was observed to be prolonged. The attenuation of proliferation potential was strongly associated with either the induction of p27^Kip1 or the impairment in mitogenic signal transduction driven by the epidermal growth factor (EGF) and EGF receptor (EGFR). We found that the leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1), a repressor of EGFR, was induced in the absence of AHR in vitro and in vivo. The LRIG1 tends to degrade via a proteasome dependent manner by interacting with AHR in wild-type cells. Either LRIG1 or a disintegrin and metalloprotease 17 (ADAM17) were accumulated in AHR-defective cells, consequently accelerating the degradation of EGFR, and attenuating the response to mitogenic stimulation. We also affirmed low AHR but high LRIG1 levels in lung tissues of chronic obstructive pulmonary disease (COPD) patients. This might partially elucidate the sluggish tissue repairment and developing inflammation in COPD patients.     

Neurofibromin Deficiency Causes Epidermal Growth Factor Receptor Upregulation through the Activation of Ras/ERK/SP1 Signaling Pathway in Neurofibromatosis Type 1-Associated Malignant Peripheral Nerve Sheet Tumor

Neurofibromatosis type 1 (NF1) is an autosomal dominant human genetic disorder. The progression of benign plexiform neurofibromas to malignant peripheral nerve sheet tumors (MPNSTs) is a major cause of mortality in patients with NF1. Although elevated epidermal growth factor receptor (EGFR) expression plays a crucial role in the pathogenesis of MPNST, the cause of EGFR overexpression remains unclear. Here, we assessed EGFR expression levels in MPNST tissues of NF1 patients and NF1 patient-derived MPNST cells. We found that the expression of EGFR was upregulated in MPNST tissues and MPNST cells, while the expression of neurofibromin was significantly decreased. Manipulation of NF1 expression by NF1 siRNA treatment or NF1-GAP-related domain overexpression demonstrated that EGFR expression levels were closely and inversely correlated with neurofibromin levels. Notably, knockdown of the NF1 gene by siRNA treatment augmented the nuclear localization of phosphorylated SP1 (pSP1) and enhanced pSP1 binding to the EGFR gene promoter region. Our results suggest that neurofibromin deficiency in NF1-associated MPNSTs enhances the Ras/ERK/SP1 signaling pathway, which in turn may lead to the upregulation of EGFR expression. This study provides insight into the progression of benign tumors and novel therapeutic approaches for treatment of NF1-associated MPNSTs.     

Squamosamide Derivative FLZ Protects Retinal Pigment Epithelium Cells from Oxidative Stress through Activation of Epidermal Growth Factor Receptor (EGFR)-AKT Signaling

Reactive oxygen species (ROS)-mediated retinal pigment epithelium (RPE) cell apoptosis is attributed to age-related macular degeneration (AMD) pathogenesis. FLZ, a novel synthetic squamosamide derivative from a Chinese herb, Annona glabra, has displayed significant cyto-protective activity. In the current study, we explored the pro-survival effect of FLZ in oxidative stressed-RPE cells and studied the underlying signaling mechanisms. Our results showed that FLZ attenuated hydrogen peroxide (H₂O₂)-induced viability decrease and apoptosis in the RPE cell line (ARPE-19 cells) and in primary mouse RPE cells. Western blotting results showed that FLZ activated AKT signaling in RPE cells. The AKT-specific inhibitor, MK-2206, the phosphoinositide 3-kinase (PI3K)/AKT pan inhibitor, wortmannin, and AKT1-shRNA (short hairpin RNA) depletion almost abolished FLZ-mediated pro-survival/anti-apoptosis activity. We discovered that epidermal growth factor receptor (EGFR) trans-activation mediated FLZ-induced AKT activation and the pro-survival effect in RPE cells, and the anti-apoptosis effect of FLZ against H₂O₂ was inhibited by the EGFR inhibitor, PD153035, or by EGFR shRNA-knockdown. In conclusion, FLZ protects RPE cells from oxidative stress through activation of EGFR-AKT signaling, and our results suggest that FLZ might have therapeutic values for AMD.