人源性肺癌噬菌体展示单链抗体库的构建

目的:构建人源性肺癌噬菌体单链抗体库,为筛选肺癌相关抗原的抗体奠定基础。方法:提取肺癌转移淋巴结总RNA,用RT-PCR技术扩增人抗体重链可变区(VH)和轻链可变区(VL)基因,在体外将VH和VL连接成单链抗体(ScFv)基因,并克隆到噬菌粒载体pCANTAB 5E中,电转化至感受态的大肠杆菌TG1,经辅助噬菌体超感染,形成噬菌体单链抗体库,采用限制性内切酶鉴定其多样性。结果:从肺癌转移淋巴结中成功提取RNA,逆转录PCR扩增出人可变区基因,连接形成单链抗体,最终构建了库容为1.2×108的抗人肺癌单链抗体库。BstNⅠ酶切法证明构建的抗体库具有良好的多样性。结论:成功地构建了噬菌体展示的抗人肺癌单链抗体库,为进一步筛选肺癌相关蛋白的可溶性抗体奠定了基础。     

小细胞肺癌抗独特型单链抗体的表达及活性研究

目的:在大肠杆菌中高效表达小细胞肺癌(SCLC)抗独特型抗体3F6单链抗体(ScFv),并获得具有生物学活性的ScFv。方法:从SCLC抗独特型抗体3F6小鼠杂交瘤细胞中提取总RNA,反转录为cDNA。利用小鼠抗体骨架区共用引物,PCR扩增单抗重链可变区(VH)和轻链可变区(VL)。通过人工设计的柔性连接肽(Gly4Ser)3连接构建3F6ScFv。再将其重组到原核表达载体pQE31中,构建3F6ScFv表达载体。转化大肠杆菌M15,IPTG诱导表达,用NiNTA树脂对表达产物进行变性纯化。通过凝胶(SephacrylS200)柱上在位复性后,用竞争ELISA检测复性的3F6ScFv活性。结果:获得了SCLC抗独特型抗体3F6的VH和VL基因,构建了3F6ScFv表达质粒。在大肠杆菌中高效表达3F6ScFv,表达蛋白的相对分子质量为32×103,以包涵体形式存在。纯化后获得较纯的3F6ScFv蛋白,经复性后可竞争2F7抗体与SCLCNIHH128细胞结合。结论:成功构建、表达、纯化和复性了SCLC抗独特型抗体3F6ScFv,获得有活性的3F6ScFv,为SCLC抗独特型抗体的进一步研究奠定了基础。     

抗人膀胱癌单克隆抗体重链可变区基因的克隆及其原核表达载体的构建

目的 克隆抗人膀胱癌单克隆抗体重链可变区基因(VH)，并构建其原核表达载体。方法从能分泌抗人膀胱癌单克隆抗体的杂交瘤细胞BDI-1中提取总RNA，通过RT-PCR扩增出VHcDNA。用HindⅢ和XhoⅠ酶切纯化的RT-PCR产物和原核表达载体pET28a( )，在T4DNA连接酶作用下室温连接。重组质粒经酶切鉴定，阳性克隆测序并进行序列分析。结果扩增出VHcDNA片段，大小约为370bp，重组质粒的酶切鉴定结果与预期一致。VH基因序列长度为366bp，编码122个氨基酸。VH基因属于鼠免疫球蛋白重链11亚类。结论成功克隆出抗人膀胱癌单克隆抗体重链可变区基因，并成功构建其原核表达载体。     

抗人整合素β3亚基单链抗体基因的构建及在大肠杆菌中表达

目的:构建抗人整合素β3亚基单链抗体(ScFv)基因,在大肠杆菌中表达并获得具有活性的ScFv。方法:从分泌抗人整合素β3亚基单抗(mAb)的杂交瘤细胞4F12中提取总RNA,RTPCR扩增VH和VL基因,通过PCR在VH和VL基因间插入柔性连接子(Gly4Ser)3,并将其克隆至原核表达载体pQE中,获得含β3抗体基因的高效表达载体pQEβ3ScFv。将重组子转化大肠杆菌M15后诱导表达,并对表达产物进行纯化和凝胶柱上在位复性。结果:获得抗β3单抗的VH和VL基因,构建了pQEβ3ScFv,并在大肠杆菌中获得了表达,表达蛋白相对分子质量约为26×103,以包涵体形式存在,纯化和复性后,ELISA证实其具有良好的抗原结合活性。结论:成功构建、表达了抗人整合素β3亚基的ScFv基因,并获得了有活性的ScFv。     

抗内毒素噬菌体抗体库的构建及筛选

目的构建一个鼠源性的抗内毒素单链噬菌体抗体库,从中筛选出对内毒素具有较高亲和力的单链抗体。方法从小鼠脾细胞中提取总RNA,通过RT-PCR技术扩增出小鼠抗体重链、轻链可变区基因（VH,VL）,用Linker将VH,VL交联形成单链抗体可变区片段（ScFv）。经NotⅠ,SfiⅠ双酶切后与经同样双酶切的pCANTAB5E载体相连,转化入大肠杆菌TG1以构建鼠抗内毒素单链噬菌体抗体库。在援救噬菌体抗体库后,用内毒素淘筛特异性的ScFv,富集的噬菌体阳性克隆重新感染TG1。在96孔板分别援救单个含特异性ScFv的TG1菌落,最后随机挑选出190个菌落经ELISA检测抗内毒素ScFv。结果小鼠血清中抗内毒素的效价为1∶12800。提取的总RNA浓度为12.3813μg/ml,纯度较好。扩增出的VH长约340bp,VL约320bp,ScFv约800bp。转化入TG1后有约1.9×107个菌落。淘筛一轮过后即有3×104阳性菌落长出,190个菌落经ELISA检测有2个阳性克隆。结论成功地构建了一个库容量为1.9×107的鼠抗内毒素单链噬菌体抗体库,并从中筛选出了2株抗内毒素ScFv。     

小细胞肺癌2F7单抗ScFv的高效表达及复性研究

目的 在大肠杆菌中高效表达小细胞肺癌单抗2F7的单链抗体（ScFv)，并获得具有生物学活性的ScFv。方法 利用PCR方法将2F7单抗重链可变区（VH）和轻链可变区（VL）通过一人工设计的柔性连接肽（Linker)连接，再将单链抗体基因重组到原核表达载体pQE31中，构建单链抗体高效表达载体pQE-2F7-ScFv。将pQE-2F7-ScFv质粒转化大肠杆菌M15后诱导表达，并对表达产物进行纯化和稀释复性。结果 获得了2F7单链抗体的高效表达，表达蛋白大小约27.4kD，以包涵体形式存在。包涵体蛋白在经过变性、纯化和稀释复性后，获得了有功能的单链抗体。结论 成功地构建和表达了小细胞肺癌单抗F27的单链抗体，并对其进行了纯化和复性，将进一步促进2F7单抗小分子抗体的应用。     

结肠癌单抗MC5的噬菌体呈现型单链可变区片段的制备

背景与目的：MC5是一种特异性良好的针对人结肠癌的鼠源性单克隆抗体,而将鼠源性抗体小型化可使其用于在体研究时引起人抗鼠抗体反应的可能性大大降低。本研究的目的是制备MC5的噬菌体呈现型单链可变区片段（ScFv)。方法：从分泌MC5的杂交瘤细胞分离mRNA,RT-PCR分别扩增抗体的重,轻链可变区DNA（VH和VL DNA）,两者经linker DNA连接形成ScFvDNA,将ScFvDNA与噬粒载体pCANTAB5E的连接产物转化于大肠杆菌TG1,经M13KO7辅助噬菌体感染后,获得重组噬菌体抗体ScFv,以高表达MC5结合抗原的细胞株SW480对重组噬菌体抗体ScFv进行两轮筛选后,随机挑取克隆经ELISA筛选呈现MC5 ScFv的噬菌体单克隆,经竞争ELISA对阳性克隆结合抗原的能力进行鉴定。结果：VH,VL和ScFvDNA分别约为340bp,320bp和750bp,在随机筛检的25个克隆中得到10个呈现MC5ScFv的噬菌体单克隆,其中结合抗原能力强的克隆有3个,结论：用噬菌体呈现技术成功地制备了单抗MC5的ScFv,为拓展该抗体的应用范围奠定了基础。     

抗人脑胶质瘤基因重组单抗的研究

苏州医学院附二院神经外补脑肿瘤研究室黄强等（215004）从该室先前建立的鼠原性抗人脑胶质瘤单抗SZs。杂交瘤细胞中抽提总RNA，RTPCR扩增VH和VL基因，测序结果分别为348hP（116个氨基酸）和318bp（106个氨基酸），证实为SZ39。重、轻键可变区基因后，采用重组技术，分别将VH和VL基因片断与人免疫球蛋白IgG1重链CH1和轻链K恒定区基因拼接，构建表达载体PHEN1SZ39Fab／Hu，又将SZ39VH和VL基因片断，以通用Linker进行连接，构建表达载体PHEN1SZ39SoFv，尔后分别在抑制性大肠杆菌HB2151中表达。两者的表达产物均为可溶性…     

抗人大肠癌单链抗体基因的克隆与表达

背景与目的：单链抗体相对于完整抗体具有免疫源性低、对肿瘤组织穿透力强的特点,日益成为肿瘤诊断和治疗的良好导向载体。本研究的目的是将抗人大肠癌单克隆抗体ND－1的重链可变区VH和轻链可变区VL基因借助一短肽序列（Gly4Ser)3进行重组,构建单链抗体基因ND－1scFv,并使其在大肠杆菌中表达。方法：采用RT－PCR技术从能够分泌ND－1单抗的鼠杂交瘤细胞中扩增VH和VL基因,通过重叠延伸拼接PCR在VH和VL基因间引入连接短肽,体外构建ND－lscFv基因,经过常规转化和筛选,将其克隆至PET－28a( )表达载体,由IPTG诱导在大肠杆菌BL21中表达为ND－lscFv与His-Tag的融合蛋白。表达产物用Ni-NTA resin亲和层析方法纯化,并采用ELISA方法检测其免疫活性。结果：序列分析表明,ND－lscFv基因全长732bp,VH354bp位于上游;VL330bp位于下游。SDS－PAGE显示,重组蛋白相对分子量30kDa,与预期结果一致。scFv表达产物以不溶性包涵体形式存在,经亲和层析纯化后蛋白纯度达94％。ELISA结果显示scFv保留了与亲本抗体ND－1相似的免疫活性。结论：成功地构建了抗人大肠癌单链抗体ND－lscFv,并在大肠杆菌中获得了较高水平的功能性表达。     

抗人CD3人/鼠嵌合抗体基因的构建

为了降低鼠源抗人CD3单抗的免疫原性．增加其在人体内的生物活性及治疗作用，使该抗体能更广泛更有效地长期多次用于人体治疗肿瘤、器官移植排斥反应及自身免疫性疾病。本文采用PCR技术从分泌抗CD3单抗的杂交瘤细胞HIT3a的mRNA中分离克隆了抗体的轻重链可变区基因的cDNA。以此轻重链可变区cDNA为特异探针从HIT3a基因文库中分离带有调控序列的功能性轻重链可变区基因，并将其插入到含有人k轻链及人71重链恒定区基因的哺乳动物表达载体中成功地构建了抗人CD3人／鼠轻重链嵌合抗体基因，为研制人抗CD3入／鼠嵌合抗体完成了关键性的第一步。     

抗CD3或B7.1与CD28共刺激PBLs膜表面分子表达与肝癌细胞凋亡的相关性

为探讨腺病毒载体介导的外源性Rb基因导入对膀胱癌细胞生长的抑制作用,为膀胱癌的基因治疗提供实验依据,构建了Rb基因的复制缺陷型重组腺病毒载体.体外转染人膀胱癌细胞株EJ.应用免疫组化法、免疫印迹及聚合酶链反应技术检测外源性Rb基因腺病毒载体的转染效率及Rb基因表达效果;用流式细胞仪分析细胞周期;以细胞计数及同位素掺入技术观察外源性Rb基因对EJ细胞生长的抑制效果.结果显示腺病毒载体可有效地将外源基因导入EJ细胞.Rb基因重组腺病毒载体转染细胞后,胞内DNA合成减少,细胞生长受到抑制.流式细胞仪分析显示68%的EJ细胞生长停滞在GO/GI期.结果提示,外源性Rb基因重组腺病毒载体转染膀胱癌细胞可有效抑制细胞生长     

野生型p53基因的导入对膀胱癌细胞抑制作用的观察

转染外源野生型ｐ５３基因对膀胱癌ＥＪ细胞的抑制作用。方法将含外源野生型ｐ５３基因的（ａｄ┐Ｗｔｐ５３）转染膀胱癌ＥＪ细胞,观察生长曲线,细胞周期变化及裸鼠体内抑瘤试验。结果转染了ａｄ┐Ｗｔｐ５３的ＥＪ细胞在体外生长速率下降,在裸鼠体内致瘤性丧失,流式细胞仪显示,ＤＮＡ合成前期或静止期的细胞比例增高。另外,ａｄ┐Ｗｔｐ５３直接注射到肿瘤组织内,可使外源野生型ｐ５３基因在肿瘤细胞内有效、稳定的表达,肿瘤表现为生长减缓,最后停止生长并有缩小。结论腺病毒载体介导基因转染效率高,速度快,安全,是很有前途的体内基因治疗载体。     

野生型PTEN基因高表达对膀胱移行细胞癌EJ细胞的抑癌作用

目的 探讨外源性野生型人酪氨酸磷酸酶（PTEN）基因的高表达对膀胱移行细胞癌EJ细胞的抑癌作用。方法 利用携带人PTEN基因的野生型、磷酸酶域突变型质粒体外分别转染人膀胱移行细胞癌EJ细胞。Western blot检测目的基因PTEN的表达,观察细胞形态变化及超微结构变化;MTIO法检测细胞增殖率及转染细胞对吡柔比星（THP）和丝裂霉素（MMC）的敏感性;Western blot法检测bcl-2蛋白的表达。以空载质粒作为对照。结果 质粒转染后,EJ细胞的PTEN蛋白表达上升75．0％。转染野生型质粒后,EJ细胞异型性低,出现典型凋亡小体,细胞增殖率下降40．1％,bcl-2蛋白表达被下调,并提高了对THP和MMC的敏感性。而转染突变型质粒的EJ细胞则无此作用。结论 野生型PTEN基因在体外对膀胱移行细胞癌EJ细胞增殖有明显抑制作用,诱导细胞凋亡,磷酸酶域突变型PTEN基因无此作用。野生型PTEN的抑癌作用可能与其对bcl-2蛋白表达的下调有关。     

Fas抗体诱导的膀胱癌细胞凋亡

背景与目的：Fas是死亡因子,可以诱导细胞的凋亡性死亡,但许多表达Fas的恶性肿瘤细胞却不能进行凋亡性死亡,可能与其表达水平低下有关,为此我们研究了细胞Fas表达水平与抗Fas治疗生物学效应之间的相互关系。方法：分别将低表达Fas的膀胱癌细胞系EJ细胞进行脂质体介导的方法转染Fas基因和肿瘤坏死因子α（TNFα)处理,并用流式细胞直接免疫荧光术检测Fas的表达;单细胞电泳和流式细胞技术检测鼠抗人Fas单克隆抗体DX2 IgG1κ诱导转染Fas基因的、经TNFα处理的和未转染未处理的EJ细胞的细胞DNA损伤和凋亡。结果：流式细胞直接免疫荧光术检测EJ细胞Fas表达阳性率19．18％,经TNFα处理后的EJ细胞Fas表达阳性率28．03％,转染Fas基因后的EJ细胞Fas分子表达阳性率68．69％。鼠抗人Fas单克隆抗体DX2 IgG1κ诱导的EJ细胞组细胞电泳后所产生的拖尾现象轻微;DX2 IgG1κ对TNFα处理组的拖尾现象明显,而对转Fas基因组可引起最强的细胞拖尾现象,经统计学分析后表明,3组细胞的尾长与总长的比值之间差异均有显著统计学意义,P＜0．01;流式细胞技术检测EJ细胞和转Fas基因组EJ细胞中的凋亡细胞分别为7．4％和66．3％。结论：EJ细胞系对Fas抗体触发细胞凋亡的敏感性依赖于细胞表面Fas的表达水平。     

转bak基因促膀胱癌多药耐药细胞凋亡的研究(英文)

目的观察转入 bak 基因对膀胱癌多药耐药(MDR)细胞的杀伤效果,探讨其可能的机制。方法用脂质体将 bak 基因导入 MDR 细胞,通过原位杂交法检测 bak mRNA 的表达,同时用 SABC 免疫组化法分析 bak 和 Bcl-2的表达。采用细胞计数法检测细胞生长抑制率,流式细胞仪检测细胞周期的变化。荧光染色观察细胞形态。结果转入 bak 基因后,MDR 细胞的生长明显受抑制(P<0.05)。细胞周期分析可见凋亡峰,凋亡率35%。细胞中可见 bak 阳性表达(P<0.05),Bck-2表达显著减少(P<0.05)。凋亡细胞在荧光显做镜下形成凋亡小体。结论转入 bak 基因可显著促进 MDR 细胞的凋亡,其作用机制与下调 Bcl-2基因的表达有关。     

转bak基因促膀胱癌多药耐药细胞凋亡的研究

目的 观察转入bak基因对膀胱癌多药耐药(MDR)细胞的杀伤效果,探讨其可能的机制。方法 用脂质体将bak基因导入MDR细胞,通过原位杂交法检测bak mRNA的表达,同时用SABC免疫组化法分析bak和Bcl-2的表达。采用细胞计数法检测细胞生长抑制率,流式细胞仪检测细胞周期的变化。荧光染色观察细胞形态。结果转入bak基因后,MDR细胞的生长明显受抑制(P<0.05)。细胞周期分析可见凋亡峰,凋亡率35％。细胞中可见bak阳性表达(P<0.05),Bcl-2表达显著减少(P<0.05)。凋亡细胞在荧光显微镜下形成凋亡小体。结论 转入bak基因可显著促进MDR细胞的凋亡,其作用机制与下调Bcl-2基因的表达有关。     

Expression of a mutant hTERT in human bladder carcinoma cell line T24 and its clinical significance

Objective: To construct a mutant pEGFP- hTERT expression vector, to observe its steady expression in transfected human bladder carcinoma cell line T24 and its role in molecular regulatory mechanisms of telomerase, and to provide a new target gene for bladder cancer. Methods:PCR amplification was performed by using primers based on the known gene sequence of hTERT. PCR production was cloned into plasmid pGEMT-T easy and the sequence of mutant hTERT gene was analyzed. A recombinant mutant hTERT vector (pEGFP-hTERT) was constructed at the EcoR I and Sa/I sites of the pEGFP-C1 vector. After transfecting the fusion gene into bladder carcinoma cell line T24 by calcium phosphate-DNA coprecipitation, the steady expression of GFP-hTERT fusion protein was tested by fluorescent light microscopy. The proliferation changes of bladder carcinoma cell line T24 were detected by light microscopy and senescence correlated [3-galactosidase staining. Results: Identification of pEGFP-hTERT by enzyme digestion showed that mutant hTERT fragment had been cloned into EcoR I and Sal I sites of the pEGFP-C1 vector. The steady expression of GFP-hTERT fusion protein was localized in the nucleus of transfected cells. Expression of senescence-associated ~-galactosidase in transfected cells gradually increased with extended cultured time and cell growth was suppressed. Conclusion: The mutant-type hTERT gene suppresses the proliferation of bladder carcinoma cell line T24 by competitive effect on telomerase activity. This suggests that hTERT gene might be a suitable gene target for bladder cancer therapy.     

ppGalNAc T1 as a Potential Novel Marker for Human Bladder Cancer

Objectives: To investigate the effect of glycopeptide-preferring polypeptide GalNAc transferase 1 (ppGalNAcT1 ) targeted RNA interference (RNAi) on the growth and migration of human bladder carcinoma EJ cells invitro and in vivo. Methods: DNA microarray assays were performed to determine ppGalNAc Ts(ppGalNAc T1-9)expression in human bladder cancer and normal bladder tissues. We transfected the EJ bladder cancer cell linewith well-designed ppGalNAc T1 siRNA. Boyden chamber and Wound healing assays were used to investigatechanges of shppGalNAc T1-EJ cell migration. Proliferation of shppGalNAc T1-EJ cells in vitro was assessedusing [3H]-thymidine incorporation assay and soft agar colony formation assays. Subcutaneous bladder tumorsin BALB/c nude mice were induced by inoculation of shppGalNAc T1-EJ cells and after inoculation diametersof tumors were measured every 5 days to determine gross tumor volumes. Results: ppGalNAc T1 mRNA inbladder cancer tissues was 11.2-fold higher than in normal bladder tissues. When ppGalNAc T1 expressionin EJ cells was knocked down through transfection by pSUPER-shppGalNAc T1 vector, markedly reducedincorporation of [3H]-thymidine into DNA of EJ cells was observed at all time points compared with the emptyvector transfected control cells. However, ppGalNAc T1 knockdown did not significantly inhibited cell migration(only 12.3%). Silenced ppGalNAc T1 expression significantly inhibited subcutaneous tumor growth comparedwith the control groups injected with empty vector transfected control cells. At the end of observation course (40days), the inhibitory rate of cancerous growth for ppGalNAc T1 knockdown was 52.5%. Conclusion: ppGalNAcT1 might be a potential novel marker for human bladder cancer. Although ppGalNAc T1 knockdown caused noremarkable change in cell migration, silenced expression significantly inhibited proliferation and tumor growthof the bladder cancer EJ cell line.     

Human bladder carcinoma cell lines as indicators of oncogenic change relevant to urothelial neoplastic progression.

Analysis of human tumour-derived cell lines has previously resulted in the identification of novel transformation-related elements and provided a useful tool for functional studies of different genes. To establish the utility of such cell lines as indicators of change relevant to urothelial cancer, we have characterised the expression of five genes (p53, MDM2, Rb, E-cadherin, APC) within a panel of human bladder carcinoma cell lines. Using single-strand conformation polymorphism (SSCP) and direct sequencing, p53 mutations were identified in 7/15 (47%) cell lines reflecting events reported in bladder tumours. Immunohistochemical analysis of p53 in cultured cells and in paraffin-embedded sections of xenografts from the cell line panel revealed discordant results. An absence of p53 nuclear staining was associated with an exon 5 mutation in EJ and with multiple p53 mutations found in J82. Two cell lines positive for p53 staining in the absence of detectable mutation displayed overexpression of MDM2 (PSI, HT1197) in Western blot analysis. Loss or aberrant Rb expression was recorded in 5/15 (TCCSUP, SCaBER, 5637, HT1376, J82) cell lines. Absence of E-cadherin was recorded in 5/15 cell lines (TCCSUP, EJ, KK47, UM-UC-3, J82) with loss of alpha-catenin in immunoprecipitated E-cadherin complexes of CUBIII. Western blot analysis of APC revealed a truncated protein in 1/15 (CUBIII) cell lines. The characterisation of oncogenic events within this panel of human bladder carcinoma cell lines establishes a representation of change observed in bladder tumours and better defines the genotypic background in these experimental human cell models of neoplastic progression.     

Apoptin induces apoptosis in human bladder cancer EJ and BIU-87 cells

Objective:To investigate whether apoptin is a apoptosis-inducing protein with a potential for bladder cancertherapy. Methods: We constructed a PCDNA3/Apoptin eukaryotic expression vector, and transfected this vectorinto bladder cancer cell lines BIU-87 and EJ, then observed the results by RT-PCR, transmission electronmicroscopy, MTT assay and the flow cytometry (TUNEL method). Results: PCDNA3/Apoptin successfullyinduced a high level apoptosis in both bladder cancer cell lines, compared with the controls (p<0.05). Conclusions:Apoptin can induce high level apoptosis in human bladder cancer EJ and BIU-87 cells, which suggests a potentialfor human bladder cancer therapy.