人TNF-αmRNA实时荧光定量PCR检测标准的构建

目的：克隆人TNF-α cDNA，作为人TNF-α mRNA定量检测的标准品。方法：用RT-PCR法从人外周血单个核细胞的总mRNA中逆转录扩增TNF-α的cDNA，将纯化的TNF-α cDNA与pUCm-T载体进行连接，转化宿主菌DH-5α，然后提取重组质粒DNA，用限制性核酸内切酶Hind Ⅲ,EcoR Ⅰ进行双酶切鉴定并测序分析，最后对质粒标准进行实时荧光定量PCR检测。用聚乙二醇沉淀法纯化质粒并检测λ200nm吸光度，确定原液的重组质粒拷贝浓度并以此制备荧光定量PCR梯度浓度标准品。结果：酶切鉴定、PCR扩增及测序分析均证实TNF-αcDNA重组到pUCm—T载体上。结论：成功克隆了TNF-α实时荧光PCR定量标准。     

白纹伊蚊β-肌动蛋白实时定量PCR方法的建立与分析

采用T-A克隆技术,在白纹伊蚊β-肌动蛋白的基因序列上设计引物,PCR扩增后将特异性产物连入T载体中,提取质粒,经测序分析验证后,测定浓度,稀释获得标准品,采用SYBR green法进行实时定量PCR,并绘制标准曲线,作为白纹伊蚊各种基因实时定量PCR检测中的内参照物.结果表明：利用此标准品制备的标准曲线具有较高的扩增效率和良好的线性关系（斜率为-3.3287,R2=0.9980）;实时定量PCR熔解曲线分析表明,温度在83℃±0.5℃的PCR产物是白纹伊蚊肌动蛋白序列上的特异性产物,表明此标准品是白纹伊蚊肌动蛋白特异性的.本实验成功建立白纹伊蚊β-actin基因实时定量PCR方法,可作为内参照物运用于白纹伊蚊基因差异表达的研究.     

人骨形成蛋白2基因克隆及真核表达载体的构建

在大肠杆菌中克隆人骨形成蛋白2基因并获得真核表达载体。由人成骨瘤细胞中提取总RNA，利用逆转录PCR方法扩增获得人骨形成蛋白2基因cDNA；将此基因片段重组到pGEM-T克隆载体中，转化到大肠杆菌DH5α后，蓝白斑筛选阳性克隆，利用限制性酶切、PCR扩增和核苷酸序列分析鉴定重组质粒；将pGEM-T克隆载体中人骨形成蛋白2基因重组到pcDNA3．1真核表达载体中，用限制性酶切和PCR扩增鉴定重组质粒。结果表明：重组在两种质粒中的基因片段为人骨形成蛋白2基因全编码序列。克隆获得人骨形成蛋白2基因．并得到此基因的真核表达载体，为人骨形成蛋白2的表达打下了基础。     

成骨细胞特异性转录因子Cbfa1重组腺病毒的构建、纯化及表达

目的构建成骨细胞特异性转录因子Cbfa1重组腺病毒载体,以期用于骨缺损、脊柱融合的体内、外研究。方法以含有全长cDNA的pCMVβ/Cbfa1为模板,PCR扩增Cbfa1,T-A克隆,酶切亚克隆到穿梭质粒pAdTrack—CMV上,在BJ5183细菌内和pAdEasy-1同源重组,筛选阳性克隆,酶切、PCR及测序鉴定,线性化后脂质体法转染293T细胞进行包装、扩增,利用报告基因GFP对病毒滴度和感染效率进行监测,CsCl梯度离心纯化病毒。AdEasy1／Cbfa1感染NIH3T3细胞后Western-blotting检测Chfa1蛋白的表达。结果测序、酶切及PCR证实Cbfa1基因重组腺病毒载体构建成功。AdEasy1／Cbfa1感染NIH3T3细胞后Western-blotting检测到Cbfa1蛋白的表达。结论成功构建了含有小鼠Cbfa1基因的重组腺病毒载体,为下一步研究基因治疗骨缺损、脊柱融合奠定基础。     

荧光定量PCR法在重组逆转录病毒pLXSN-BDNF滴度测定中的应用

目的制备含大鼠脑源性神经营养因子（BDNF）基因的逆转录病毒，建立荧光定量PCR测定滴度的方法。方法扩增BDNF基因，构建重组质粒pLXSN-BDNF，将其转染包装细胞，经G418筛选、病毒浓缩后用荧光定量PCR法和克隆形成法测定滴度。结果经PCR、酶切和测序鉴定，BDNF基因成功插入逆转录病毒载体中，筛选得到稳定的分泌重组病毒细胞系。重组病毒100倍浓缩后经荧光定量PCR法和克隆形成法测定的滴度分别为6．92×10^6拷贝/ml和3．2×10^5CFU/ml，两种方法测得的结果差异有统计学意义（P〈0．05）。结论成功扩增BDNF基因，制备了重组病毒pLX—SN-BDNF，建立了荧光定量PCR检测滴度的方法，为基因治疗青光眼性视神经损伤的实验研究提供重要参考指标。     

类人慢性粒细胞性白血病小鼠模型的建立

 目的：为了进一步阐明慢性粒细胞性白血病(chronic myeloid leukemia,CML) 的发病机制、寻找新的治疗靶点,有必要建立CML动物模型。方法：首先改进逆转录病毒包装技术,在相同实验条件下,改变以下条件之一,如质粒的质量、包装细胞的状态、转染当天包装细胞的密度等,进行病毒滴度的测定,优化实验条件后进行后续实验。实验组为BCR/ABL(含BCR/ABL融合基因的逆转录病毒载体)组小鼠。供体小鼠经5-氟尿嘧啶（5-FU）预处理后,骨髓细胞经p210 BCR/ABL逆转录病毒上清感染,感染的骨髓细胞经尾静脉注射给经致死剂量X光照射的受体小鼠。观察移植后BCR/ABL组小鼠的活动情况、发病鼠外周血和骨髓的细胞形态、肝脾病理改变等。同时观察MigR1(逆转录病毒空载体)组小鼠。结果：通过提高质粒的质量、改善包装细胞的状态、优化转染当天包装细胞的密度等,提高了病毒的滴度,用于小鼠移植模型实验。BCR/ABL组小鼠均于移植后19～25 d发病死亡。发病时外周血及骨髓均见中晚幼及成熟粒细胞大量增生,肝脾肿大伴正常结构破坏及大量粒细胞浸润。MigR1组小鼠均无发病。结论: 通过改进逆转录病毒包装技术,提高包装病毒的滴度,我们在体外将BCR/ABL转入小鼠骨髓细胞并移植入受体小鼠,成功建立了类人CML小鼠模型。     

稳定分泌重组HBV载体颗粒细胞系的构建

目的 制备一个持续分泌表达杀稻瘟菌素抗性基因(BsdR)的重组乙型肝炎病毒细胞系.方法 删除HBV质粒中各基因的表达,在S基因区插入目的 基因BsdR,以构建载体质粒pCH-BsdR;具有G418抗性的无包装信号的HBV辅助质粒pcDNA3.1-CH3142与载体质粒共转染HepG2细胞,经G418和Bsd共筛选,获得细胞克隆,进行系列检测.结果 挑选36个细胞克隆,经检测,最终筛选出3个细胞株,具有形成松弛环状DNA的能力,细胞培养上清液中病毒定量分别为4.1×106、3.6×106、1.2×106拷贝/ml.观察到有囊膜的重组HBV颗粒的形成.未检测到野生型HBV的产生.结论 该细胞系能够大量制备重组HBV载体颗粒,有助于HBV载体在基因治疗方面的应用和易感细胞系的筛选.     

人热休克蛋白70基因的原核表达

目的 表达人热休克蛋白70（HSP70）并进行鉴定。方法 用PCR方法扩增人HSP70基因片段，经T-A克隆法克隆到载体pUCm-T中，并进行DNA测序，将人HSP70基因片段从载体pUCm-T中酶切后，构建重组表达载体pGEX-4T-1-HSP70，并转化大肠杆菌JM109，用IPTG诱导，收集细菌，菌体裂解后进行SDS-PAGE及Western blot检测。结果 人HSP70基因的PCR产物约为1.9kb。序列测定结果证实，所获目的序列与文献[3]报道的相一致，经EcoRⅠ和XhoⅠ酶切鉴定证实。人HSP70基因已成功地克隆到表达载体pGEX-4T-1中，构建的表达载体pGEX-4T-1-HSP70，能很好地在大肠杆菌中表达相对分子质量（Mr)为96000并具有抗原特性的融合蛋白，结论 成功地克隆并表达了HSP70基因，为研究HSP70的结构。功能与临床应用提供了必要条件。     

Pre-miR-10a重组腺病毒载体对K562细胞增殖的抑制作用

目的:观察在K562细胞高表达miR-10a对细胞增殖及凋亡的影响。方法:用pAd-pre-miR-10a重组腺病毒载体感染K562细胞,采用RT-PCR检测感染后K562细胞中miR-10a和bcr/abl融合基因的表达水平,Western blot法检测BCR/ABL融合蛋白表达水平,MTT、流式细胞术(FCM)分别检测感染后K562细胞的增殖及凋亡。结果:与对照组相比,K562细胞在转染pAd-pre-miR-10a重组腺病毒载体后,其miR-10a表达水平明显升高、bcr/abl融合基因水平显著降低;BCR/ABL融合蛋白表达明显下调、K562细胞增殖活力被抑制、细胞凋亡增加,差异均具有统计学意义(P<0.05)。结论:pAd-pre-miR-10a重组腺病毒载体能明显抑制K562细胞的增殖、促进细胞凋亡。     

大鼠Hes1基因真核表达载体的构建及瞬时表达在神经前体细胞分化中的作用

目的 探讨Hes1基因高表达对神经前体细胞分化的影响. 方法从大鼠脑组织中提取总BNA,用RT-PCR方法获得Hes1基因的全长cDNA,插入pGEM-T-Easy克隆载体中进行序列测定,测序正确后将其亚克隆至表达载体pCDNA3.1,用脂质体将重组质粒转染原代培养的神经前体细胞,经G418筛选获得抗性细胞克隆,用RT-PCR方法鉴定Hes1基因在神经前体细胞基因组中的存在,实时荧光定量PCR检测Hes1基因在转染细胞中的过表达情况. 结果 经限制性内切酶酶切图谱分析和DNA序列测定,证实目的 基因已插入重组质粒,RT-PCR证明,经G418筛选得到的转基因神经前体细胞克隆的基因组DNA中存在Hes1基因;实时荧光定量PCR进一步证明,转基因神经前体细胞Hes1基因的mRNA高表达. 结论 构建了大鼠Hes1基因的真核表达载体,获得了高表达Hes1基因的神经前体细胞克隆.Hes1基因高表达可抑制神经前体细胞Ngn1的表达,并促进神经前体细胞向神经胶质细胞的分化.     

蛋白转导域介导BCR/ABL抗原对CML患者T细胞的活化作用

目的：研究蛋白转导域(PTD)介导的BCR／ABL抗原对慢性髓细胞白血病(CML)患者T细胞的特异性活化作用。方法：利用基因工程技术，将PTD基因与CML b3a2 bcr／abl基因融合并原核表达。将纯化的PTD—BCR／ABL融合蛋白与CML患者外周血单个核细胞(PBMC)体外共孵育，用流式细胞仪分别检测CD4^ 、CD8^ T细胞上活化抗原CD25的表达。结果：终浓度为100mg／L的PTD—BCR／ABL抗原体外刺激4d后，10例CML患者中，5例表现为CD8^ T细胞活化，2例表现为CD4^ T细胞活化，其中有1例CD8^ 和CD4^ T细胞同时活化；而作为对照的BCR／ABL抗原刺激组无一例表现为CD8^ 或CD4^ T细胞活化。结论：PTD能将外源性BCR／ABL抗原转导入抗原呈递细胞内，加工呈递后激活抗原特异性CD8^ 及CD4^ T细胞，为CML特异性CD8^ 、CD4^ T细胞的体外活化及细胞免疫治疗开辟一条新的途径。     

A novel tricolor, dual-fusion fluorescence in situ hybridization method to detect BCR/ABL fusion in cells with t(9;22)(q34;q11.2) associated with deletion of DNA on the derivative chromosome 9 in chronic myelocytic leukemia

Dual-color, dual-fusion fluorescence in situ hybridization (D-FISH) can accurately detect and quantify cells with BCR/ABL fusion in <1% of 500 nuclei in 80% of patients with chronic myelocytic leukemia (CML) and t(9;22)(q34;q11.2). The remaining patients have one of three forms of atypical D-FISH patterns; these patterns have different sensitivities to detect disease. Neoplastic cells with one ABL, one BCR, and one BCR/ABL fusion are particularly problematic, because normal cells with coincidental overlap have the same pattern. For these patients, the normal cutoff for D-FISH is >23%. We tested a new method that incorporates an aqua-labeled probe for the argininosuccinate synthetase (ASS) gene into the conventional BCR/ABL D-FISH probe set. This tricolor D-FISH (TD-FISH) method takes advantage of the aqua-labeled ASS probe to distinguish between neoplastic and normal cells. We used TD-FISH to study 20 normal specimens and 35 specimens from 20 patients with known loss of both BCR and ABL from the derivative chromosome 9. The results show that TD-FISH effectively discriminates between cells with overlapping BCR and ABL signals from cells with true BCR/ABL fusion and improves the ability to quantify minimal residual disease from >23% to >1% of 500 interphase nuclei.     

Fluorescence in situ hybridization characterization of different cryptic BCR-ABL rearrangements in chronic myeloid leukemia

Using fluorescence in situ hybridization probes, obtained from bacterial artificial chromosome (BAC) libraries that relate to sequences either side of the BCR and ABL genes, this study characterized four chronic myeloid leukemia cases with cryptic BCR-ABL rearrangements. Each case showed evidence of a different underlying mechanism: one case showed a microinsertion of BCR into ABL, another a microinsertion of ABL into BCR, and the third showed a complex rearrangement including deletion of adjacent flanking sequences, consistent with the reverse translocation model of cryptic rearrangement. The fourth case also showed evidence of a more complex rearrangement involving chromosome 1.     

Integration of amplified BCR/ABL fusion genes into the short arm of chromosome 17 as a novel mechanism of disease progression in chronic myeloid leukemia

We describe the cases of two patients with Philadelphia chromosome-positive chronic myeloid leukemia (CML), in whom the extramedullary blastic phase developed during disease progression. The similar clinical presentations of these patients was accompanied by gain of identical secondary chromosome abnormalities, that is, monosomies 9, 14, and 22, and by a clustered amplification of the BCR/ABL fusion gene. The additional copies of the BCR/ABL fusion gene were integrated into the short arm of structurally abnormal chromosomes 17 in both patients. The conformity of these genetic features in two patients with a rare disease manifestation leads us to the assumption that either the clustered amplification of the BCR/ABL fusion gene or the integration of this cluster into the short arm of chromosome 17 or both are associated with extramedullar disease progression in CML. Furthermore, the insertion of amplified BCR/ABL fusion genes into structurally abnormal chromosomes provides a novel mechanism of disease progression in BCR/ABL-positive CML.     

Gene expression analysis of BCR/ABL1-dependent transcriptional response reveals enrichment for genes involved in negative feedback regulation

Philadelphia (Ph) chromosome-positive leukemia is characterized by the BCR/ABL1 fusion protein that affects a wide range of signal transduction pathways. The knowledge about its downstream target genes is, however, still quite limited. To identify novel BCR/ABL1-regulated genes we used global gene expression profiling of several Ph-positive and Ph-negative cell lines treated with imatinib. Following imatinib treatment, the Ph-positive cells showed decreased growth, viability, and reduced phosphorylation of BCR/ABL1 and STAT5. In total, 142 genes were identified as being dependent on BCR/ABL1-mediated signaling, mainly including genes involved in signal transduction, e.g. the JAK/STAT, MAPK, TGFB, and insulin signaling pathways, and in regulation of metabolism. Interestingly, BCR/ABL1 was found to activate several genes involved in negative feedback regulation (CISH, SOCS2, SOCS3, PIM1, DUSP6, and TNFAIP3), which may act to indirectly suppress the tumor promoting effects exerted by BCR/ABL1. In addition, several genes identified as deregulated upon BCR/ABL1 expression could be assigned to the TGFB and NFkB signaling pathways, as well as to reflect the metabolic adjustments needed for rapidly growing cells. Apart from providing important pathogenetic insights into BCR/ABL1-mediated leukemogenesis, the present study also provides a number of pathways/individual genes that may provide attractive targets for future development of targeted therapies. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.     

Deletion of any part of the BCR or ABL gene on the derivative chromosome 9 is a poor prognostic marker in chronic myelogenous leukemia

To evaluate the prognostic significance of submicroscopic deletions of the ABL or BCR gene associated with t(9;22) in chronic myelogenous leukemia (CML), we investigated the incidence of an ABL or BCR deletion on derivative chromosome 9 using fluorescence in situ hybridization (FISH). FISH was performed using the LSI BCR/ABL dual-fusion translocation probe on bone marrow cells of 86 patients with CML. Of 86 patients, ABL deletion was detected in 13 (15.1%) patients and BCR deletion in 8 patients (9.3%). Patients with ABL deletion showed shorter event-free survival time (EFS) than those without ABL deletion (P = 0.020). Patients with BCR deletion showed significantly short overall survival time (OS; P = 0.039). Patients with ABL and/or BCR deletion (14/86 patients, 16.3%) showed significantly short OS and EFS (median OS, 43.0 months; median EFS, 40.0 months), compared to the patients without any BCR or ABL gene deletions (median OS, 94.0 months; median EFS, 90.0 months; P = 0.041 for OS, P = 0.008 for EFS). All the patients with BCR deletion, except for one, had a concomitant ABL deletion, suggesting that BCR deletion occurs in conjunction with ABL deletion. In patients with ABL deletion only, BCR/ABL rearrangement with b2a2 mRNA type tended to be more frequent than in patients without any deletion of the two genes (P = 0.073). Deletion of any of the BCR or ABL genes on derivative chromosome 9 was associated with both short OS and EFS. We conclude that deletion of not only the ABL gene, but also of the BCR gene, is a poor prognostic marker that indicates rapid disease progression in CML.