阻断TGF α-EGFR自泌环对胰腺癌细胞体外生长的影响

目的研究阻断ＴＧＦα－ＥＧＦＲ自泌环对胰腺癌细胞生长的影响。方法构建了反义ＥＧＦＲ的表达载体ｐＣＭＶ－ＡＳ－ＥＧＦＲ,转染已经反义ＴＧＦα转化的胰腺癌ＰＣ－７细胞,经Ｇ４１８筛选,获得稳定的双重转化细胞系ＰＣ－７／ＡＳ－ＴＧＦα／ＡＳ－ＥＧＦＲ。经Ｓｏｕｔｈｅｒｎｂｌｏｔ、Ｎｏｒｔｈｅｒｎｂｌｏｔ、１２５Ｉ－ＥＧＦ结合试验分析双重转染细胞系基因的整合及表达。ＤＮＡ凝胶电泳、流式细胞术、原位凋亡检测细胞凋亡。结果双重转染细胞系有外源ＴＧＦα基因的整合及表达,内源性ＥＧＦＲ及ｃｙｃｌｉｎＤ１ｍＲＮＡ表达下调、细胞表面ＥＧＦＲ受体表达下降,与反义ＴＧＦα单独作用比较,反义ＥＧＦＲ与反义ＴＧＦα的联合作用更强。３Ｈ－ＴｄＲ掺入率由２５％降至１４．５％。生长抑制率由７８．８％提高到８６．０％、软琼脂集落形成能力完全丧失。双重抑制后,细胞更容易发生凋亡。结论对胰腺癌中异常信号传导途径的阻断,能明显地抑制肿瘤恶性生物学行为,使肿瘤细胞恶性表型部分逆转。     

幽门螺杆菌感染的高增殖状态及其与TGF—α,EGFR表达的关系

本研究采用免疫组化ＬＳＡＢ法对幽门螺杆菌阳性和阴性胃粘膜增殖细胞核抗原（ＰＣＮＡ）转化生长因子α（ＴＧＦ－α）表皮生长因子受体（ＥＧＦＲ）表达进行对比分析，结果表明ＨＰ阳性胃粘膜ＰＣＮＡ，ＴＧＦ－α，ＥＧＦＲ的表达显著高于ＨＰ阴性胃粘膜（Ｐ〈０．０５），且在不典型增生时达高峰，结果提示ＨＰ感染的胃粘膜处于高增殖状态，粘膜高增殖状态可能与ＴＧＦ－α／ＥＧＦＲ过量表达有关，这也是ＨＰ致胃癌发生的机制之     

表皮生长因子受体反义基因转染对人恶性胶质瘤细胞体外生长的影响

目的探讨表皮生长因子受体（ＥＧＦＲ）反义基因转染对人恶性胶质瘤细胞Ｕ８７ＭＧ体外生长的影响。方法构建ＥＧＦＲ反义基因表达载体，应用脂质体转染法将其导入Ｕ８７ＭＧ细胞；ＰＣＲ方法鉴定转染克隆；Ｗｅｓｔｅｒｎ印迹杂交检测ＥＧＦＲ蛋白表达水平；通过绘制生长曲线和软琼脂集落形成实验测定反义ＥＧＦＲ基因对恶性胶质瘤细胞体外生长的抑制作用。结果转染反义ＥＧＦＲ基因的细胞克隆株ＡＳ１ＡＳ６的ＥＧＦＲ蛋白表达水平均有不同程度的降低；ＡＳ１ＡＳ６细胞体外生长明显减慢，ＡＳ１ＡＳ６细胞克隆形成率明显降低。表明Ｕ８７ＭＧ细胞体外生长速度和恶性转化能力均与ＥＧＦＲ表达呈正相关。结论反义ＥＧＦＲ基因转染可以明显抑制Ｕ８７ＭＧ细胞生长，ＥＧＦＲ对Ｕ８７ＭＧ细胞生长具有重要的调控作用     

表皮生长因子受体反义基因转染对人恶性胶质细胞体外生长的影响

目的 探讨表皮生长因子受体（ＥＧＦＲ）反义基因转染对人恶性胶质瘤细胞Ｕ８７ＭＧ体外生长的影响,方法 构建ＥＧＦＲ反义基因表达载体,应用脂质体转染法将其导入Ｕ８７ＭＧ细胞,ＰＣＲ方法鉴定转染单克隆,Ｗｅｓｔｅｍ印迹杂交检测ＥＧＦＲ蛋白表达水平。通过绘制生长曲线和软琼脂集落形成实验测定反义ＥＧＦＲ基因对恶性胶质瘤细胞体外生长的抑制作用,结果 转染反义ＥＧＦＲ基因的细胞克隆株ＡＳ１－ＡＳ６的ＥＧＦＲ蛋白     

转化生长因子与卵巢癌的关系

转化生长因子α、β（ＴＧＦ－α、ＴＧＦ－β）与卵巢癌的发生、发展、预后均有关系。ＴＧＦ－α是上皮来源卵巢癌细胞的一种自分泌生长因了有皮生长因子受体（ＥＧＦＲ）有高度亲和力。实验证明大多数卵巢癌细胞系中有ＴＧＦ－α表达,部分卵巢癌细胞系可被外源笥ＴＧＦ－α促进生长,部分可被ＴＧＦ－α抗体抑制生长。ＴＧＦ－α／ＥＦＧＦＲ共同表达组病人存活率最低,ＴＧＦ－α　／ＥＧＦＲ水平增高提示病人预后不良及生存时间     

rhG-CSF cDNA高表达质粒的构建及其在COS7细胞中的表达

目的：构建一个能在哺乳动物细胞中高表达人粒细胞集落刺激因子（Ｇ－ＣＳＦ）ｃＤＮＡ的重组质粒。方法：利用化学合成引物，进行ＰＣＲ，对人Ｇ－ＣＳＦｃＤＮＡ５＇ＡＵＧ侧翼序列进行翻译优化突变。测序确证后，重组入表达载体ｐＥＤ，构建成质粒ｐＥＤ－ＧＣＳＦ，用ＤＥＡＥ－Ｄｅｘｔｒａｎ法转染ＣＯＳ７细胞，ＥＬＩＳＡ法定量测定ｒｈＧ－ＣＳＦ表达水平。结果：转染ＣＯＳ７细胞后４８ｈ收集的上清ｒｈＧ－ＣＳＦ表达量为５２ｎｇ／ｍｌ，７２ｈ为２３０ｎｇ／ｍｌ，显示ｒｈＧ－ＣＳＦ获得了暂时性高表达。结论：ｐＥＤ－ＧＣＳＦ是一个能在哺乳动物细胞中高效表达ｒｈＧ－ＣＳＦ的真核表达质粒。     

人结肠癌中EGFR、EGF及TGF－α的基因表达

本文报道了人结肠癌细胞系（ＬＳＴ１７４、ＨＴ１０、Ｌｏｖｏ）中表皮生长因子受体（ＥＧＦＲ）及其配体即表皮生长因子（ＥＧＦ）和转化生长因子（ＴＧＦα）的基因表达。从人结肠癌细胞系细胞提取总ＲＮＡ，经Ｎｏｒｔｈｅｒｎ吸印转移后，用［α－３２Ｐ］－ｄＣＴＰ标记的ＥＧＦ、ＴＧＦα及ＥＧＦＲｃＤＮＡ探针进行杂交，放射自显影结果表明三个结肠癌细胞系中均有ＥＧＦｍＲＮＡ及ＥＧＦＲｍＲＮＡ的表达。ＬＳＴ１７４ＨＴ１０中亦有ＴＧＦα的基因表达，Ｌｏｖｏ无ＴＧＦα的表达。结果说明人结肠癌存在生长因子自泌循环。这些癌细胞系中自泌的生长因子作用于自身的ＥＧＦＲ，不断地刺激其自身增殖，这可能是癌细胞自主无休止生长的主要原因之一。     

rhG—CSF cDNA表达质粒的构建及其在COS7细胞中的表达

目的：构建一个能在哺乳动物细胞中高表达人粒细胞集落刺激因子（Ｇ－ＣＳＦ）ｃＤＮＡ的重组质粒。方法：利用化学合成引物，进行ＰＣＲ，对人Ｇ－ＣＳＦｃＤＮＡ５ＡＵＧ侧翼序列进行翻译优化突变。测序确证后，重组人表达载体ｐＥＤ，构建成质粒ＰＥＤ－ＧＣＳＦ，用ＤＥＡＥ－Ｄｅｘｔｒａｎ法转染ＣＯＳ７细胞，ＥＬＩＳＡ法定量测定ｒｈＧ－ＣＳＦ表达水平。结果：转染ＣＯＳ７细胞后４８ｈ收集的上清ｒｈＧ－ＣＳＦ表达量为５     

鼠抗人TNF-α单域抗体基因在大肠杆菌中的融合表达

ＲＴ－ＰＣＲ法获得鼠抗人肿瘤坏死因子－α单克隆抗体Ｅ６轻,重链可变区基因序列,分别构建融合表达载体ｐＧＥ６ＶＨ和ｐＧＥ６ＶＬ,利用大肠杆框图 系统表达ＶＨ和ＶＬ单域抗体蛋白。方法：将ＲＴ－ＰＣＲ法获得的Ｅ６ＶＨ和Ｅ６ＶＬ基因分别克隆入融合表达载体ｐＧＥＸ４Ｔ－１中,使它们受控于Ｐｔａｃ启动子,转化大肠杆菌ＤＨ５α,经异丙基－β－Ｄ－硫代半乳糖苷（ＩＰＴＧ）诱导,１００ｇ／ＬＳＤＳ－ＰＡＧＥ检测表达     

贮脂细胞TGF-1反义基因转移及对细胞外基质合成的抑制作用

目的探讨ＴＧＦβ１在肝纤维化贮脂细胞激活和细胞外基质产生中的作用。以及对细胞外基质基因的表达和自身ｍＲＮＡ表达的作用。方法将ＴＧＦβ１的基因序列反向插入逆转录病毒载体ｐＬＸＳＮ,构建反义ＴＧＦβ１的逆转录病毒载体ｐＬＡＴＳＮ,用ＰＡ３１７包装细胞包装,获得高滴度的逆转录病毒。将携有反义ＴＧＦβ１ｃＤＮＡ的逆转录病毒载体ｐＬＡＴＳＮ导入人的贮脂细胞株ＬＩ９０内,选择稳定转染的贮脂细胞株培养,应用ＰＣＲ、ＲＴＰＣＲ检测反义基因的表达,用ＥＬＩＳＡ、免疫组织化学和原位杂交等方法检测ＴＧＦβ１和细胞外基质的产生。结果贮脂细胞株ＬＩ９０内有反义ＴＧＦβ１的表达,且其合成分泌ＴＧＦβ１和细胞外基质如ＦＮ、ＣｏｌＡ１降低。结论反义ＴＧＦβ１ＲＮＡ可以抑制贮脂细胞的激活和内源性ＴＧＦβ１和细胞外基质的产生,为抗纤维化基因治疗提供理论基础     

Influence of recombinant retroviral vector expressing antisense TGF alpha on malignant phenotype of human pancreatic carcinoma cell line.

OBJECTIVE To observe the effects of antisense TGF alpha on the growth of human pancreatic carcinoma cell line cells.

METHODS A recombinant retroviral vector expressing antisense TGF alpha was constructed, and transfected the ecotropic packaging cell line psi-2 with lipofectin. After the amphotropic packaging cell line PA317 was transfected with the virus supernatant of psi-2, the replication-defective, amphotropic retroviral supernatant was used to infect human pancreatic carcinoma cell line PC-7. Following puromycin selection, puromycin-resistant colonies were pooled and expanded to a cell line PC-7/AS-TGF alpha.

RESULTS The retroviral integration in the genomes of psi-2, PA317 and transformant PC-7 cells was confirmed by Southern blot hybridization. Northern blot hybridization showed a down regulation of endogenous TGF alpha in PC-7/AS-TGF alpha cell line. The high levels of growth inhibition and reduction of 3H-TdR incorporation in PC-7/AS-TGF alpha were evident. Also, the soft agar colony-formation and tumorigenicity in nude mice were significantly suppressed by antisense TGF alpha.

CONCLUSIONS The antisense TGF alpha expressing vector can block the target gene expression, suppress the cell growth and partially reverse the malignant phenotype of pancreatic carcinoma cells.

     

Influence of recombinant retroviral vector expressing antisense TGFα on malignant phenotype of human pancreatic carcinoma cell line

ＩｎｆｌｕｅｎｃｅｏｆｒｅｃｏｍｂｉｎａｎｔｒｅｔｒｏｖｉｒａｌｖｅｃｔｏｒｅｘｐｒｅｓｉｎｇａｎｔｉｓｅｎｓｅＴＧＦαｏｎｍａｌｉｇｎａｎｔｐｈｅｎｏｔｙｐｅｏｆｈｕｍａｎｐａｎｃｒｅａｔｉｃｃａｒｃｉｎｏｍａｃｅｌｌｉｎｅＸｕＹａ许雅，ＬｉｕＴｏ...     

Inhibiting effect of murine double minute-2 oncogene on apoptosis induced by retroviral-mediated wild-type p53

OBJECTIVE To investigate the effects of wild-type p53 (wtp53) on inducing apoptosis by restoring wtp53 expression in pancreatic adenocarcinoma cell line (PC-2) which contains mutant p53, and the interaction between murine double minute-2 (MDM2) and wtp53 in pancreatic adenocarcinoma.

METHODS A recombinant retroviral vector expressing wild-type p53 was constructed and packaged by packaging cell line PA317 cells using calcium phosphate coprecipitation method. The supernatant of the packaged cells PA317 was used to transfect the pancreatic carcinoma cell line (PC-2), then a transformed cell line PC-2/swtp53 was established. The recombinant vector pCMV-MDM2 was transduced into PC-2/swtp53 cell line by lipofectin-mediated method, a double transfected cell line (PC-2/swtp53/pCMV-MDM2) was formed. To determine the integration and expression of exogenous wtp53 gene in the transfected cells, polymerase chain reaction (PCR), Western blot and immunoprecipitation analyses were performed. Apoptosis was analyzed by means of flow cytometry, in situ terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) analysis and DNA agarose gel electrophoresis.

RESULTS Transduction with the retroviral vector resulted in integration and expression of wtp53 gene in host cells. The apoptotic cells in PC-2/swtp53 and PC-2/swtp53/pCMV-neo cell lines were 12.1%-12.9%, while the double transfected cell line, PC-2/swtp53/pCMV-MDM2, showed less (3.2%) apoptotic cells than its parent cell lines.

CONCLUSIONS Restoration of expression of wild-type p53 with a retroviral vector can increase programmed cell death of pancreatic adenocarcinoma cells (PC-2) containing mutant p53. The overexpression of MDM2 protein has a negative regulating role in wtp53-induced apoptosis in PC-2 cell.

     

腺病毒介导的野生型p53基因表达对入胰腺癌细胞生长的影响

目的探讨恢复野生型ｐ５３（ｗｔｐ５３）基因表达对胰腺癌细胞生长的影响。方法构建一个Ｅ１区缺失但能表达ｗｔｐ５３基因的５型腺病毒载体Ａｄ５ＣＭＶｗｔｐ５３，该载体含有人ＣＭＶ启动子、人野生型ｐ５３基因和ＳＶ４０ｐｏｌｙＡ信号。载体经腺病毒包装细胞２９３细胞包装、扩增后，转染人胰腺癌ＰＣ－２细胞。ＰＣＲ和Ｎｏｒｔｈｅｒｎ印迹分析证实，转染的细胞有外源ｗｔｐ５３基因的表达。结果与对照组相比，转染有Ａｄ５ＣＭＶｗｔｐ５３的ＰＣ－２细胞生长速度减慢、增殖率降低，软琼脂集落形成能力丧失。结论以腺病毒为载体恢复野生型ｐ５３在胰腺癌细胞的表达，可抑制癌细胞的生长和部分逆转其恶性表型。     

小干扰RNA对前列腺癌表皮生长因子受体及其胞内效应蛋白表达的影响

目的 应用RNA小干扰(SiRNA)技术影响表皮生长因子受体(EGFR)及其胞内效应蛋白水平的表达,观察其对激素非依赖前列腺癌细胞在体外以及在实验裸鼠模型体内的生长情况的影响.方法 筛选出最有效的EGFR SiRNA,采用慢病毒为载体,转染激素非依赖前列腺癌细胞(HIPC)PC-3,MTT法检测细胞生长抑制情况,荧光实时定量PCR和Western印迹法检测细胞EGFR及其胞内效应蛋白Akt和MAPK的表达水平和磷酸化程度.同时,建立HIPC裸鼠模型,瘤体内注射EGFR SiRNA,观察肿瘤生长情况.结果慢病毒为载体的EGFR SiRNA对PC-3细胞转染率可稳定在75%,并显著抑制PC-3细胞生长率,仅为40%～50%,其作用可能为沉默细胞EGFR mRNA及其蛋白的表达,抑制效率>90%(P<0.01);而且,Akt和MAPK表达水平和磷酸化均明显降低,表达抑制率分别为76.49%和47.15%,P<0.05.与对照组比较,EGFR SiRNA体内抑瘤率为34.83%,P<0.05.结论 慢病毒介导的靶向EGFR SiRNA可以在体内外显著抑制HIPC生长,其机制可能是沉默EGFR表达,进而抑制胞内效应蛋白的作用,后者可作为未来靶向治疗的目标.     

EFFECTS OF TGF β1 AUTOCRINE BLOCKAGE ON OSTEOSARCOMA CELLS

Objective To evaluate the effects of transforming growth factor β1 (TGF β1) autocrine blockage on proliferation activity and drug sensitivity of osteosarcoma. Methods Northern blot, MTT determination, and ^3H thymidine incorporation were used to investigate the effects of antisense TGF β1 gene on osteosarcoma. Results The proliferation of osteosarcoma cells transfected by antisense TGF β1 gene was suppressed markedly, and adriamycin sensitivity was significantly increased. Conclusion Blockage of osteosarcoma cells TGF β1 autocrine loop inhibits cell proliferation and enhances chemother apy sensitivity.     

Construction of Antisense Transforming Growth Factorβ_1 Gene and Its Effect on the Proliferation by Expression in Osteosarcoma Cells

Summary:To construct the antisense transforming growth factorβ1(TGFβ1)gene and investigatethe effect of TGFβ1 autocrine loop blockage on the proliferation of osteosarcoma cells.TGFβ1 cDNAwas cloned by RT-PCR from human osteosarcoma cells(MG-63)and inserted into pcDNA_3 to con-struct an antisense expression vector,which was dubbed pcDNA_3-TGFβ1(-).MTT was used to de-tect the proliferation of osteosarcoma cells transfected by antisense TGFβ1 gene.Our results showedthat the proliferation of the transfected osteosarcoma cells was suppressed markedly.It is concludedthat TGFβ1 autocrine loop blockage in osteosarcoma cells could inhibit cell proliferation,which mightbe helpful for gene therapy of osteosarcoma.     

EFFECTS OF TGF β1 AUTOCRINE BLOCKAGE ON OSTEOSARCOMA CELLS

Objective To evaluate the effects of transforming growth factor β1 (TGF β1) autocrine blockage on proliferation activity and drug sensitivity of osteosarcoma.Methods Northern blot, MTT determination, and 3H thymidine incorporation were used to investigate the effects of antisense TGF β1 gene on osteosarcoma.Results The proliferation of osteosarcoma cells transfected by antisense TGF β1 gene was suppressed markedly, and adriamycin sensitivity was significantly increased.Conclusion Blockage ofosteosarcoma cells TGF β1 autocrine loop inhibits cell proliferation and enhances chemotherapy sensitivity.     

人EGFR基因真核表达质粒的构建及其在293细胞中的表达

目的:构建人表皮生长因子(EGFR)基因真核表达系统,拟为EGFR靶向腺病毒准备包装细胞.方法:用RT-PCR法,从人A431细胞中逆转录出EGFR基因cDNA,插入到pcDNA3.1(+)质粒中,拟构建EGFR真核表达载体,经测序证实.用脂质体将重组质粒转染293细胞,经G418筛选获得稳定表达EGFR重组克隆,用Western blot鉴定转染细胞中EGFR基因的表达.结果:经限制性内切酶酶切及测序结果分析证实EGFR基因已插入重组质粒.Western blot方法证实转基因293细胞中存在人EGFR基因的表达.结论:成功构建的人EGFR/pcDNA3.1(+)真核表达系统能够在293细胞稳定表达.