B7-H4基因对SKOV3细胞生长功能的影响

目的： 初步探讨B7-H4基因对人卵巢癌细胞株SKOV3细胞生长和致瘤性的影响。方法：RT-PCR法扩增编码基因, 构建真核表达载体PEGFP-N1/B7-H4,以脂质体为载体将重组质粒PEGFP-N1和PEGFP-N1/B7-H4分别导入SKOV3细胞中,筛选建立高表达的细胞株。MTT法绘制体外培养细胞生长曲线,将转染前后的肿瘤细胞分别接种于SCID小鼠的腹部皮下观察其致瘤性。结果：成功构建了人B7-H4真核表达载体,SKOV3/B7-H4细胞高表达B7-H4,转染后肿瘤细胞体外生长速度明显增快。SKOV3/B7-H4细胞在小鼠体内的致瘤性较SKOV3/neo细胞和野生型SKOV3细胞明显升高。结论： B7-H4基因导入细胞后在体外和体内具有明显加快肿瘤生长的作用,可作为肿瘤基因治疗的靶向基因。     

免疫缺陷鼠重建免疫后抑制移植瘤生长的研究

目的：研究严重联合免疫缺陷（severity combined immunodeficiency，SCD）鼠在转移正常鼠淋巴细胞后免疫重建的功效及其抑制移植瘤生长的机理。方法：将肝癌细胞HHCC-9724接种到免疫重建SCID鼠，观察移植瘤生长情况、CD4CD8计数及其比例、免疫球蛋白定量、脾细胞毒试验以及癌细胞凝集试验。结果：①重建免疫功能后SCID鼠对移植瘤有排斥作用。②SCID小鼠免疫重建后4-6周CD4及CD8计数分别为0.12、0.16，CD4/CD8为0.75。③免疫重建SCID小鼠产生较高水平的免疫球蛋白能对癌细胞产生凝集效应。④Balb/c鼠和CBA/N鼠的脾细胞对癌细胞排斥作用与免疫重建的SCID鼠相比较，后者仍显得较弱。结论：严重联合免疫缺陷SCID鼠可以通过免疫重建，发挥其抑制肿瘤生长的功效。     

右旋柠烯乳剂对人胃癌移植瘤生长和转移的抑制作用

目的　研究并探讨右旋柠烯乳剂 (D limonene)对人胃癌生长和转移的抑制作用及其机制。　方法　采用人胃癌BGC 82 3细胞株经反复传代成实体瘤的完整组织块 ,建立人胃癌裸小鼠原位移植瘤模型。将 4 0只荷瘤裸小鼠随机分成 4组 ,移植后第 5d开始分别用生理盐水灌胃、5 氟尿嘧啶 (5 FU)腹腔注射、D limonene灌胃、D limonene灌胃 +5 FU腹腔注射共 7周。第 8周处死动物 ,测量原位肿瘤瘤重并计算抑瘤率 ,检测肿瘤细胞凋亡指数 (AI)、肿瘤微血管密度 (MVD)及免疫组织化学测定肿瘤组织血管内皮生长因子 (VEGF)的表达变化 ,光镜与电镜观察组织细胞超微结构变化 ;观察荷瘤鼠腹膜、肝、其他脏器肿瘤转移及腹水情况。　结果　D limonene组、联用组分别与对照组相比 ,胃癌的原位肿瘤瘤重与抑瘤率、AI、MVD、VEGF下调 ,差异有显著性 (P <0 0 5 )。腹膜、肝转移受到明显抑制 (P <0 0 5 )。　结论　D limonene通过抑制肿瘤微血管形成 ,诱导胃癌细胞凋亡 ,抑制了体内胃癌的生长和转移。     

VEGF-ASODN抑制裸鼠胃癌移植瘤微血管生长

目的 研究血管内皮细胞生长因子反义寡核苷酸（VEGF-ASODN）对裸鼠荷人胃癌移植瘤微血管的生长抑制作用。方法 人工合成硫代磷酸化VEGF-ASODN,转染胃癌细胞SGC-7901, 实时荧光定量RT-PCR检测细胞RNA起始拷贝数, ELESA法检测VEGF 蛋白含量,MTT检测细胞生存力,细胞生长曲线检测细胞生长。建立裸鼠荷胃癌移植瘤模型。实验分为4组：（1）VEGF-ASODN组,（2）错义寡核苷酸组,（3）生理盐水组,（4）无荷瘤对照组。结果 VEGF-ASODN能降低胃癌细胞VEGFmRNA的水平,显著降低胃癌细胞及培养液VEGF 蛋白含量,降低细胞生存力、抑制细胞生长。VEGF-ASODN还能显著降低荷瘤裸鼠血清VEGF蛋白水平、减小移植瘤的体积和重量、降低移植瘤微血管密度。结论 VEGF-ASODN抑制移植瘤微血管的生长。     

人卵巢癌荷瘤裸鼠肿瘤微环境局部F4 / 80 阳性巨噬细胞表达Foxp3

目的:探讨人卵巢癌裸鼠腹腔荷瘤模型体内F4/80阳性巨噬细胞是否表达Foxp3,初步探索卵巢癌改造免疫微环境促进自身发展的新机制。方法:应用人卵巢癌细胞系SKOV3构建人卵巢癌裸鼠腹腔荷瘤模型为实验组,以未处理裸鼠为对照组,流式细胞术检测两组外周血和腹水中F4/80阳性巨噬细胞Foxp3的表达情况。应用流式细胞分选两组腹水中F4/80阳性巨噬细胞,分别应用Western blot和PCR检测该细胞中Foxp3在蛋白和mRNA水平的表达情况。免疫荧光双染法鉴定腹腔内卵巢癌组织局部浸润F4/80阳性巨噬细胞Foxp3的表达情况。结果:流式细胞术检测两组外周血中F4/80阳性细胞均不表达Foxp3,差异无统计学意义(P0.05)。流式细胞术和Western blot显示实验组腹水F4/80阳性巨噬细胞在蛋白水平明显表达Foxp3,实时荧光定量PCR显示实验组在mRNA水平明显表达Foxp3,与对照组比较差异均有统计学意义(P0.05)。免疫荧光双染法显示卵巢癌组织可见F4/80和Foxp3双阳性细胞。结论:卵巢癌肿瘤微环境中F4/80阳性巨噬细胞表达Foxp3,为寻找卵巢癌免疫疗法新靶点奠定基础。     

不良心理应激对人卵巢癌荷瘤裸鼠皮下移植瘤生长及表皮生长因子受体、磷酸化蛋白激酶B、血管内皮生长因子蛋白表达的影响

目的 通过观察不良心理应激人卵巢癌荷瘤裸鼠皮下移植瘤的体积、重量和瘤体组织中表皮生长因子受体（EGFR）、磷酸化蛋白激酶B（p-Akt）、血管内皮生长因子（VEGF）蛋白表达情况的差异,探讨其对卵巢癌生长的影响及可能的分子机制。 方法 购置4～6周龄的雌性BALB/c裸鼠,称重,随机分两组,每组12只。A组：荷瘤组皮下移植人卵巢癌组织瘤块,不给予应激;B组：荷瘤+应激组皮下移植人卵巢癌组织瘤块,给予应激。定期测量皮下移植瘤的体积,结束应激实验后的第2天,处死全部组别（A组、B组）裸鼠,剥离肿瘤予以称重,利用免疫组织化学及Western blotting方法对A、B两组皮下移植瘤组织中的EGFR、p-Akt、VEGF蛋白表达情况进行检测。 结果 荷瘤+应激组皮下移植瘤体积及其重量显著高于荷瘤组（P＜0.01）;免疫组织化学实验提示,荷瘤+应激组中皮下移植瘤组织中的EGFR、p-Akt、VEGF蛋白表达水平高于荷瘤组（P<0.05）;Wester blotting提示,荷瘤+应激组皮下移植瘤组织中EGFR、p-Akt、VEGF蛋白表达水平显著高于荷瘤组（P<0.01）。 结论 不良心理应激可能通过EGFR及其介导的下游PI3K/Akt信号通路来促进卵巢癌的发生、发展。     

呼肠孤病毒对乳腺癌的治疗作用

为研究溶瘤呼肠孤病毒对乳腺癌的治疗作用,采用NOD/SCID鼠建立人乳腺癌组织块异种原位移植瘤模型,腹腔注射呼肠孤病毒,3天后通过HE和TUNEL观察乳腺癌的治疗效果.结果显示:没有雌激素辅助的免疫缺陷鼠,肿瘤无法长出.在移植人乳腺癌标本的同时给予免疫鼠雌激素,则移植成功率大为提高,可以达到29.6%(P<0.01)....     

转入IL-18 cDNA的鼻咽癌细胞在hu-PBL-SCID鼠中致瘤性的影响

为了探讨人白细胞介素 18(hIL 18)的表达对鼻咽癌细胞体内致瘤性的影响 ,我们构建了hIL 18的真核表达载体pcD NA3/hIL 18,转染人鼻咽癌细胞株SUNE细胞 ;然后以转染阳性的SUNE细胞和未转染的SUNE细胞接种到用健康人外周血白细胞免疫重建的SCID鼠 (hu PBL SCID鼠 ) ,观察成瘤情况。结果发现 ,所构建的真核表达载体在鼻咽癌细胞中能高效表达hIL 18;ELISA法测得转染阳性细胞培养上清液中hIL 18的含量为 (85± 10 )pg/ml,而未转染的SUNE细胞的培养上清液中hIL 18的含量低于 5pg/ml。将转染阳性的细胞克隆和未转染的SUNE细胞接种hu PBL SCID小鼠后连续观察 5 0d ,发现前者形成的肿瘤其生长速度明显慢于后者 ,其平均瘤重也有显著性差异 (P <0 0 0 1)。说明在体内hIL 18的表达能有效地抑制鼻咽癌细胞的成瘤作用。     

荷EL4肿瘤小鼠模型的建立及美法仑抑瘤作用免疫机制的探讨

目的:建立荷小鼠淋巴瘤EL4的野生型C57BL/6小鼠及其裸鼠模型,探讨美法仑(melphalan)抑瘤作用的免疫机制。方法:给正常野生型C57BL/6小鼠皮下接种小鼠淋巴瘤EL4细胞,建立荷EL4肿瘤的小鼠模型。于野生型C57BL/6小鼠皮下接种瘤细胞后12d,经腹腔给荷瘤小鼠单次注射不同剂量的美法仑,找出美法仑可发挥最大的抑瘤作用,并能致使肿瘤消退、不再复发的最小使用剂量。然后再给野生型C57BL/6小鼠及其裸鼠(遗传背景相同)皮下同时接种小鼠淋巴瘤EL4细胞建立两种荷瘤小鼠模型。同样于接种瘤细胞后12d,经腹腔给两种荷瘤小鼠模型均注射可使野生型C57BL/6小鼠肿瘤消退、不再复发的最低剂量的美法仑,以正常野生型C57BL/6小鼠为对照,观察在T淋巴细胞缺陷的裸鼠体内美法仑的抑瘤作用。结果:注射7.5mg/kg美法仑治疗后,免疫功能正常的野生型C57BL/6荷瘤小鼠的肿瘤消退;而荷瘤C57BL/6裸鼠的肿瘤仍继续生长。结论:单一剂量的美法仑对荷淋巴瘤EL4小鼠具有明显的治疗作用,其作用的发挥需要T淋巴细胞的参与,可能与T细胞的杀伤作用有关。     

NFATc1对裸鼠上皮性卵巢癌移植瘤脉管生成的影响

 目的: 探讨胞浆活化T细胞核因子1(nuclear factor of activated T-cells, cytplasmic 1, NFATc1)对人卵巢癌SKOV3细胞裸鼠移植瘤生长和肿瘤脉管生成的影响及其可能机制。方法: NFATc1 siRNA转染人上皮性卵巢癌细胞株SKOV3,免疫荧光及RT-PCR测量转染效率和基因抑制率,选取效率最高的序列建立裸鼠皮下移植瘤模型, 测量各组裸鼠肿瘤体积,观察NFATc1 siRNA的体内抗肿瘤作用。免疫组织化学检测各组肿瘤组织NFATc1的表达情况,并使用细胞角蛋白染色标记上皮性来源,CD34标记微血管,podoplanin标记微淋巴管。分别计算各组微血管及微淋巴管密度并进行统计学分析。应用RT-PCR及Western blot检测各组移植瘤组织NFATc1、CXC趋化因子受体2(CXCR2)、成纤维细胞生长因子2(FGF-2)及血小板源性生长因子BB(PDGF-BB)的mRNA及蛋白表达水平。结果: 3条特异性序列均可显著降低NFATc1的表达水平,以siRNA-1169最佳。NFATc1在空白组及阴性对照组瘤组织高表达。干扰组抑瘤率为57.08%,且重量和体积均低于2个对照组。空白组和阴性对照组的微血管密度和微淋巴管密度明显高于干扰组。对照组比较,NFATc1 siRNA可以在mRNA水平上明显抑制NFATC1、CXCR2、FGF-2和PDGF-BB的转录。Western blot各组细胞在相应位置出现NFATc1、CXCR2、FGF-2和 PDGF-BB条带,空白组与阴性对照组的吸光度最强,与干扰组比较具有显著差异。结论: NFATc1 siRNA明显抑制人卵巢癌SKOV3细胞裸鼠皮下移植瘤生长和肿瘤脉管生成,下调CXCR2、FGF-2及PDGF-BB的表达可能为其途径之一。     

骨髓增生异常综合征的-7/7q-染色体异常的检测

目的　探讨间期荧光原位杂交(fluorescence in situ hybridization,FISH)技术在检测骨髓增生异常综合征(myelodysplastic syndrome,MDS)-7/7q-染色体异常中的价值。方法　同时应用常规细胞遗传学(conventional     

重组BMP7腺病毒的构建及转染骨髓基质干细胞后的表达

根据Clonetech公司的腺病毒载体构建流程，原核表达载体pBlue-BMP7经一系列特定的限制性内切酶酶切，重组成BMP7的腺病毒载体，并转染293细胞进行大量扩增、滴度测定。重组Adeno-BMP7经限制性内切酶PI-SeeⅠ和Ⅰ-CeuⅠ双酶切获得BMP7基因片段，PCR扩增得到特异的扩增片段，表明重组的Adeno-BMP7载体构建成功，其中携带有目的基因BMP7cDNA片段。Adeno-Lac-Z的体外转染骨髓基质干细胞(BMSCs)，染色表明转染率可达90％以上；RT-PCR、免疫组化证明Adeno-BMP7转染BMSCs后BMP7在基因和蛋白水平上均有表达；转染Adeno-BMP7后的BMSCs细胞悬液裸鼠肌肉内注射后，X光片和组织学观察都表明BMP7转染可明显促进新骨的形成，与没转染Adeno-BMP7的BMSCs有显著差异。     

The participation of T7 DNA-binding protein in T7 genetic recombination

Recombination reactions were performed between ColE1 DNA bound to cellulose (DNA-cellulose) and ³H-labeled ColE1 DNA in a crude extract prepared from T7-infected cells. The amount of binding of radioactivity to DNA-cellulose depended on the presence of T7 exonuclease, which is indispensable for T7 genetic recombination in vivo. The binding reaction was specific for homologous DNA. Applying this assay to the purification of enzymes which are essential for T7 genetic recombination, a protein factor was found in the extracts from T7-infected cells, which works in cooperation with T7 exonuclease. The protein was tentatively identified as the T7 DNA-binding protein, on the basis of purification and its molecular weight (32,000). This identification was supported by the isolation of a T7 mutant defective in DNA-binding protein; which displays a 10-fold lower frequency of recombination than wild-type T7.     

骨形态发生蛋白-7及其受体的信号转导

骨形态发生蛋白-7(BMP-7)是BMP家族中的一员,具有高效的骨诱导活性,属于转化生长因子-β(TGF-β)超家族成员。BMP-7受体属于转化生长因子β(TGF-β)受体超家族的成员,是一种膜蛋白受体。BMP-7首先与Ⅱ型跨膜丝/苏氨酸激酶受体(ActRⅡ、ⅡB)结合,受体的蛋白激酶活性被激活,再与Ⅰ型受体(主要是ALK2)结合,形成异源二聚体,催化Ⅰ型受体GS区的丝氨酸和苏氨酸残基磷酸化。Ⅰ型受体被激活后,作用于Smad1、Smad5或Smad8的C端SSXS模体,使其磷酸化,再与Smad4形成复合物,进入核内与多种转录因子相互作用发挥基因调控作用。     

Identification and characterization of the CRPV E7 protein expressed in COS-7 cells

The papillomavirus E7 protein may play an important role in oncogenesis as it is the major viral protein present in human cervical cancer-derived cell lines. Because of the relevance of the cottontail rabbit papillomavirus (CRPV) system for the study of viral-induced malignancies, we characterized its E7 protein expressed by a heterologous strong promoter. An E7-specific antiserum was obtained by immunizing rabbits with a Trp E-E7 fusion protein containing the 88 carboxyl-terminal amino acids of E7. This antiserum specifically precipitated from [35S]cysteine but not from 32PO4-labeled transiently transfected COS-7 cells a 14-kDa protein. The protein was present only in the soluble cytoplasmic fraction and exhibited a heterogeneous sedimentation rate in nondenaturing glycerol gradients.     

Autocrine expression of interleukin-7 rescues lymphoid expansion in interleukin-7-deficient mice.

The murine interleukin-7 (IL-7) gene was disrupted to examine the role of IL-7 in the lymphoid system. Expansion of lymphoid cells is sharply curtailed in IL-7-deficient mice. This is evident in a dramatic reduction but not elimination of lymphoid cells in the thymus, bone marrow and spleen. The few thymocytes present express CD4 and/or CD8 markers associated with T-cell maturation. Similarly, a limited number of B cells detected in the bone marrow rearrange and express immunoglobulin genes. Small but distinct populations of B and T cells are found in the spleens of IL-7-deficient mice. Thus the signal transmitted by IL-7 plays a central role in the expansion of lymphocytes while it is not absolutely required for their maturation. A transgene that directs expression of IL-7 to lymphoid cells was found to restore the numbers of thymocytes, bone marrow B-cell progenitors and splenic lymphocytes of IL-7-deficient mice to approximately normal levels. This genetic complementation confirms that the lymphoid defect is specifically due to the absence of IL-7 and demonstrates that the expansion of lymphoid cells in an organism is regulated by their exposure to IL-7.     

Immunofluorescence of simian adenovirus 7 (SA7)--specific antigens in infected LLC-MK 2 cells and SA7 transformed cells

Antigens synthesized in LLC-MK₂ cells infected with SA7 were described using indirect immunofluorescence. When cells were reacted with sera from tumor-bearing hamsters, “T” antigens were observed as early as 10 hr post-infection (PI). In certain cells a second type of exclusively intranuclear fluorescence was observed at 16 hr PI. Specific antiviral sera reacted with viral structural antigens approximately 15–16 hr PI. Sera from hamsters immunized with density gradient-purified virus reacted with both “T” antigens and viral antigens.     

Trisomy 7 in nonneoplastic cells

The somatic mutation theory of tumorigenesis states that mutations are necessary for tumor development. On the other hand, acquired, clonal chromosomal alterations are occasionally detected in otherwise normal, nonneoplastic cells—for example, loss of sex chromosomes occurs in bone marrow cells and lymphocytes in elderly individuals—and it is therefore evident that not all mutations are by themselves sufficient for neoplasia to occur. Thus, the finding of an acquired, clonal chromosomal abnormality does not constitute proof that a lesion is neoplastic. Trisomy 7 has, as the sole clonal chromosomal aberration, been reported in a wide variety of epithelial tumor types but also in some mesenchymal and neurogenic neoplasms. It has been suggested to be a primary, i.e., tumor-initiating, abnormality in tumors of the bladder, brain, colon, kidney, lung, ovary, prostate, and thyroid. But data from cytogenetic studies of solid tumors, macroscopically normal tissue in the proximity of solid tumors, and nonneoplastic lesions now question the importance of a solitary +7 as a neoplasia-associated change. Most solid tumors in which trisomy 7 has been found as the sole change in one clone have also displayed other, cytogenetically unrelated, clones with complex karyotypic abnormalities. Such karyotypic differences among coexisting clones could indicate that the neoplasm is polyclonal, that the cytogenetically disparate clones have emerged during tumor progression from one original clone carrying submicroscopic genomic changes only, or that the clone with +7 does not represent the tumor parenchyma. The latter interpretation is supported by the finding of cells with trisomy 7 in macroscopically normal tissue outside tumors of the brain, kidney, and lung. A seemingly decisive argument against the belief that the finding of an acquired, clonal +7 proves that a neoplasm exists is the detection of clones with an extra copy of chromosome 7 in several nonneoplastic lesions and tissues, such as atherosclerotic plaques, chorionic villi, chronic pyelonephritis, Dupuytren's contracture, focal steatosis of the liver, Peyronie's disease, and rheumatoid synovitis. That the abnormality arises in vivo has been shown by in situ hybridization with chromosome 7 specific probes; +7 is no in vitro artifact. It is unknown in which cell type the trisomy occurs; some data from colon adenomas favor epithelial cells, whereas data from kidney tumors and colon carcinomas suggest that the +7 arises in cells of the immune system. This question may possibly be resolved by obtaining a pure cell line with trisomy 7 cells only, to be characterized further by immunologic and morphologic methods. Another line of investigation might be to search for clonal chromosomal abnormalities in nonneoplastic tissues in other species. Finally, it remains to be elucidated whether +7 is a neutral genome mutation or whether it confers a selective advantage upon the cell. © 1993 Wiley-Liss, Inc.