异源树突状细胞融合瘤在抗人结肠转移癌细胞免疫中的作用

目的探讨异源树突状细胞（pc）／结肠转移癌细胞融合瘤在诱导产生抗人结肠转移癌细胞免疫中的作用。方法使用50％聚乙二醇（PEG）将健康人外周血DC与结肠转移癌细胞融合，用其致敏-T淋巴细胞，使用噻唑盐（MTT）微量酶反应比色法测定T细胞增殖情况，使用^51Cr释放法测定细胞毒性T淋巴细胞（CTL）杀伤结肠转移癌细胞的作用。结果融合瘤细胞能促进T细胞增殖，在第5天达到高峰（P〈0．01）；融合瘤细胞致敏的CTL能有效杀伤结肠转移癌细胞（P〈0．01），其杀伤结肠转移癌细胞的作用强于对照靶细胞（P〈0．01）。结论异源树突状细胞融合途径能诱导产生抗结肠转移癌细胞免疫应答。     

Fas/FasL在异源融合瘤诱导结肠癌细胞早期凋亡中的作用

目的 探讨Fas/FasL通路在人异源树突状细胞（dendritic cell,DC）/结肠癌细胞融合瘤诱导结肠癌细胞凋亡中的作用.方法 使用50%聚乙二醇（PEG）将健康人外周血来源DC与结肠癌细胞SW480融合,用其致敏T淋巴细胞,采用流式细胞术检测致敏细胞毒性T淋巴细胞（CTL）对结肠癌细胞凋亡的影响;使用免疫组化法分别检测SW480细胞Fas分子的表达以及T淋巴细胞活化前后FasL的表达情况.结果 结肠癌SW480细胞的早期凋亡率为46.88%;结肠癌SW480细胞高表达Fas分子用融合瘤致敏T细胞后,其FasL分子的表达明显增加.结论 异源树突状细胞融合瘤可能通过Fas/FasL通路来诱导结肠癌细胞的早期凋亡.     

树突状细胞与尤文肉瘤细胞融合诱导抗肿瘤免疫应答的体外研究

目的检测尤文肉瘤细胞A673和树突细胞(DC)融合构建的肿瘤疫苗对尤文肉瘤细胞株A673的杀伤作用。方法应用促融合剂PEG对尤文肉瘤A673细胞和从外周血单个核细胞(PBMC)诱生的树突细胞进行融合。利用细胞因子hGMCSF和hIL4从PBMC诱生DC,并对其表型进行流式细胞仪(FCM)分析,红色荧光染料PKH26标记A673细胞,绿色荧光染料PKH67标记DC,应用促融合剂PEG融合后光镜及电镜观察DC细胞和融合细胞形态,FCM检测融合效率,通过同种混合淋巴细胞反应检测其免疫刺激活性。通过IFNγELISA法产生细胞毒性T淋巴细胞(CTL)的量,通过51Cr细胞杀伤试验检测融合细胞对A673细胞的杀伤作用。结果FCM检测出从PBMC成功诱生出CD83、CD80、CD86及HLADR高表达的成熟DC。DCs/A673融合细胞的融合效率达到23%,同种混合淋巴细胞反应显示DCs/A673融合细胞有很强的免疫刺激活性。IFNγ分泌检测显示DCs/A673融合细胞组较对照组产生CTL水平显著增高。51Cr释放法检测融合细胞体外诱导抗原特异的CTL,融合细胞激活的CTL对肿瘤细胞系A673细胞的杀伤作用强于DCA673混合组、DC组、A673组的CTL(P<0.05),作用较对照各组显著增强。结论DC与A673细胞融合体外致敏自体T淋巴细胞能生成抗原特异CTL对尤文肉瘤细胞A673有一定的杀伤作用。     

树突状细胞与尤文肉瘤细胞融合诱导肿瘤免疫应答的体外研究

目的检测尤文肉瘤细胞A673和树突细胞(DC)融合构建的肿瘤疫苗对尤文肉瘤细胞株A673 的杀伤作用.方法应用促融合剂PEG对尤文肉瘤A673细胞和从外周血单个核细胞(PBMC)诱生的树突细胞进行融合.利用细胞因子hGM-CSF和hIL-4从 PBMC诱生DC,并对其表型进行流式细胞仪(FCM) 分析,红色荧光染料PKH-26标记A673细胞,绿色荧光染料PKH-67标记DC,应用促融合剂PEG融合后光镜及电镜观察DC细胞和融合细胞形态,FCM检测融合效率,通过同种混合淋巴细胞反应检测其免疫刺激活性.通过IFN-γ ELISA法产生细胞毒性T淋巴细胞(CTL)的量,通过51Cr细胞杀伤试验检测融合细胞对A673 细胞的杀伤作用.结果 FCM检测出从PBMC 成功诱生出CD83、CD80、CD86 及HLA-DR 高表达的成熟DC.DCs/A673融合细胞的融合效率达到23%,同种混合淋巴细胞反应显示DCs/A673融合细胞有很强的免疫刺激活性.IFN-γ分泌检测显示DCs/A673融合细胞组较对照组产生CTL水平显著增高.51Cr释放法检测融合细胞体外诱导抗原特异的CTL, 融合细胞激活的CTL对肿瘤细胞系A673细胞的杀伤作用强于DC-A673混合组、DC组、A673组的CTL(P<0.05),作用较对照各组显著增强.结论 DC与A673细胞融合体外致敏自体T 淋巴细胞能生成抗原特异CTL 对尤文肉瘤细胞A673 有一定的杀伤作用.     

肿瘤浸润淋巴细胞对结肠癌细胞的杀伤作用及机制

目的探讨肿瘤浸润淋巴细胞在结肠癌细胞杀伤中的作用及机制。方法从6例结肠癌患者转移淋巴结中分离TIL细胞,采用^51Cr释放法测定其杀伤结肠癌SW480细胞的作用;采用流式细胞术测定结肠癌细胞的凋亡;采用固定化蛋白印迹法（Western blot）测定TIL细胞和结肠癌细胞Fas、FasL蛋白的表达。结果TIL细胞能有效杀伤结肠癌SW480细胞,其杀伤作用明显强于淋巴因子活化的杀伤细胞（100：1,P=0.004;50：1,P=0.002;10：1,P=0.006）和细胞因子诱导的杀伤细胞（100：1,P=0.001;50：1,P=0.002;10：1,P=0.008）,差异具有统计学意义（P〈0.01）;TIL细胞能促进结肠癌细胞的早期凋亡;TTL细胞高表达FasL分子,而SW480细胞高表达Fas分子,不表达FasL分子。结论TIL细胞能有效杀伤不表达FasL分子的结肠癌细胞,其机制可能通过Fas/FasL通路诱导结肠癌细胞的凋亡。     

尤文肉瘤基因免疫治疗的研究

目的检测尤文肉瘤融合基因EWSFLI1和人粒单核细胞集落刺激因子(hGMCSF)基因修饰的树突细胞(DC)疫苗对尤文肉瘤细胞株A673的杀伤作用。方法利用hGMCSF腺病毒(AdhGMCSF),在1000U/mlIL4作用下,从外周血单个核细胞(PBMC)诱生树突细胞(DC)并对其表型进行流氏细胞仪(FCM)分析,通过同种混合淋巴细胞反应以检测其免疫刺激活性。在lipofectamine的介导下,将含有尤文肉瘤融合基因EWSFLI1的真核表达质粒pCA13/EWSFLI1转染DC,通过RTPCR检测EWSFLI1的表达,并通过乳酸脱氢酶(LDH)释放试验检测其对A673细胞的杀伤作用。结果应用AdhGMCSF从PBMC成功诱生出CD83、CD80、CD86及HLADR高表达,CD14低表达的DC,其对同种淋巴细胞有很强的免疫刺激活性。pCA13/EWSFLI1转染DC后,RTPCR检测DC中有EWSFLI1mRNA的表达。杀伤试验结果表明,AdhGMCSF诱生、EWSFLI1修饰的DC,体外诱导抗原特异的CTL,效靶比为20∶1时对A673细胞杀伤率为(29.9500±0.0117)%,高于对照组(P<0.01)。结论AdhGMCSF能够成功地从PBMC中诱生出有功能的DC。真核表达质粒pCA13/EWSFLI1在lipofectamine的介导下转染AdhGMCSF诱生的DC,能在DC中有效地表达。此EWSFLI1基因修饰的、AdhGMCSF诱生的DC体外致敏自体T淋巴细胞,生成抗原特异CTL,对尤文肉瘤细胞A673有一定的杀伤作用     

小鼠端粒酶蛋白亚单位转染树突状细胞体外诱导特异性抗肝癌细胞免疫应答

目的 观察携带小鼠端粒酶蛋白亚单位(mTERT)基因蕈组腺病毒载体(AdmTERT)转染树突状细胞(DC)后诱发免疫效应细胞产生特异性抗肝癌细胞免疫应答的研究.方法 用流式细胞仪分析及电镜观察培养6 d DC的细胞表型及形态,Ad-mTERT重组腺病毒转染体外培养的小鼠DC,Western blot检测mTERT融合蛋白表达;用负载mTERT的DC刺激同型淋巴细胞,免疫磁珠分选CD8~+T细胞做为效应细胞,小鼠肝癌细胞株(H22)及小鼠结肠癌细胞(CT26)作为靶细胞,用酶联免疫吸附试验(ELISA)及酶联免疫斑点法(ELISPOT)检测干扰索(IFN)-γ分泌量和释放抗原特异性IFN-γ的T细胞数,~(51)Cr释放法检测细胞毒性T淋巴细胞(CTL)对肝癌细胞的杀伤活性.结果 细胞表型及形态观察证实小鼠骨髓来源的DC为成熟的树突状细胞;AdmTERT转染DC后能正确表达mTERT融合蛋白,用AdmTERT转染DC致敏的淋巴细胞IFN-γ分泌量(208.6μg/L)和分泌IFN-γ的特异性T细胞的数量(341/10~6脾细胞)都高于Ad-GFP转染的DC组(14.2μg/L,33/10~6脾细胞)和单纯DC组(12.1μg/L,19/10~6脾细胞,P＜0.05).AdmTERT修饰DC刺激产生的效应T细胞在效靶比为90:1时,对H22细胞的杀伤率(54.2%)明显高于AdGFP致敏组(8.2%)和未致敏DC组(4.5%,P＜0.05),而对CT26细胞无明显杀伤作用.结论 AdmTERT修饰的DC体外能够诱导出针对mTERT抗原特异性的CTL效应,可特异性杀伤mTERT阳性的肝癌细胞.     

gp96多肽复合物对树突状细胞成熟的影响

目的研究热休克蛋白gp96多肽复合物与小鼠骨髓来源的树突状细胞（DC）成熟的关系。方法采用GM-CSF、IL-4刺激培养小鼠骨髓细胞，增殖产生大量DC；从小鼠肝癌细胞株H22细胞中提取gp96肽复合物，体外修饰DC；通过流式细胞仪检测上清液IL-12、TNF-α细胞因子含量和DC表面主要组织相容性Ⅱ类抗原、CD40、CD80等分子表达；DC与小鼠脾淋巴细胞共同培育后，检测CD4、CD8和IFN-γ、IL-10双阳性细胞比例；以^51Cr释放法测定细胞毒性T淋巴细胞（CTL）杀伤活性。结果gp96多肽复合物修饰的DC大量分泌IL-12、TNF-α等细胞因子，高表达MHCⅡ类抗原、CD40、CD80等分子；并且能激活小鼠脾淋巴细胞，CD8^＋-IFN-γ^＋和CD4^＋-IFN-γ^＋双阳性细胞比例显著升高；能够特异性的杀伤H22癌细胞。结论gp96多肽复合物能够诱导DC成熟，体外产生特异性CTL反应。     

辅助性T细胞和细胞毒性T淋巴细胞双表位修饰的树突状细胞肿瘤疫苗治疗胃癌的实验研究

目的研究辅助性T细胞（Th）表位和细胞毒性T淋巴细胞（CTL）双表位修饰的树突状细胞（DCs）肿瘤疫苗用于胃癌免疫治疗的效果。方法用CTL表位MAGE-341-49和Th表位MAGE-322-36混合多肽冲击DCs，每周刺激脾脏T细胞1次，4周后收集多肽特异性T细胞。流式仪分析T细胞亚群分布，测定CD4^＋T细胞识别抗原细胞因子分泌及CD8^＋T细胞杀伤肿瘤细胞效能，观察双表位修饰的DCs肿瘤疫苗治疗胃癌的保护性免疫效应。结果双表位致敏的DCs体外可同时活化CD4^＋和CD8^＋T细胞，其中CD4^＋T细胞识别肿瘤细胞小鼠前胃癌细胞株MFC后分泌大量Th1型细胞因子[干扰素（IFN）-γ，白介素（IL）-2]，CD8^＋T细胞强效杀伤MFC。双表位修饰的DCs肿瘤疫苗小鼠体内免疫治疗获得抵抗后继胃癌细胞MFC的免疫保护能力，并显著高于单一表位（CTL或Th）修饰的DC8疫苗。结论Th和CTL双表位修饰的DCs肿瘤疫苗可同时激活CD4^＋Th1细胞和CD8^＋CTL抗肿瘤免疫，有效清除胃癌细胞。     

X-盒结合蛋白1和热休克蛋白靶向的树突状细胞疫苗对肾癌肿瘤免疫治疗作用的比较研究

目的:应用树突状细胞(DC)与X-盒结合蛋白1(XBP1)共培养制备XBP1-DC疫苗,通过与热休克蛋白70(HSP70)-DC疫苗对GRC2细胞的免疫杀伤作用进行比较,初步探讨应用XBP1蛋白与DC共培养制备融合瘤疫苗的可行性。方法:从肾癌患者的外周血中分离出外周血单核细胞(PBMC),经体外培养诱导为DC。以HSP70和XBP1与DC共培养制备HSP70-DC和XBP1-DC融合瘤疫苗。用HSP70-DC和XBP1-DC疫苗分别刺激患者外周血分离的T淋巴细胞,采用ELISA法检测所产生的CTL反应。以经HSP70-DC和XBP1-DC刺激形成的CTL作为效应细胞,以正常细胞、GRC2为靶细胞,测不同效靶比(10:1、20:1)下,效应细胞杀伤靶细胞的能力。结果:PBMC经细胞因子诱导后,CD1a、CD86、CD83、HLA-DR表达水平均显著高于诱导前表达水平(P0.05)。与DC组比较,XBP1-DC疫苗致敏后,CTL细胞均释放INF-γ显著增加,差异有统计学意义(P0.05),而与HSP70-DC疫苗致敏的CTL细胞比较,XBP1-DC释放的INF-γ差异无统计学意义(P0.05)。随着效靶比的升高,各组CTL细胞对GRC2细胞和RCC细胞的杀伤率均相应提高,差异均有统计学意义(P0.05)。在不同效靶比时,HSP-DC和XBP1-DC免疫的CTL对GRC2和GCC的杀伤作用差异均无统计学意义(P0.05)。结论:XBP1与DC共培养后,能增强DC的抗原呈递能力,增强T淋巴细胞分泌细胞因子的能力,从而特异性杀伤肾癌GRC2细胞系,且杀伤作用与HSP70-DC融合瘤疫苗一致,在抗肿瘤杀伤作用中具有一定的可行性。     

Modification of gene products involved in resistance to apoptosis in metastatic colon cancer cells: roles of Fas, Apaf-1, NFkappaB, IAPs, Smac/DIABLO, and AIF

BACKGROUND: Colon cancer becomes resistant to apoptosis as it acquires metastatic potential. SW480 and SW620 colon cancer cells were established from the same patient at different stages of tumor progression. The stage III colorectal cancer cell line (SW620) is more resistant to apoptosis. In the present report, we investigated the apoptotic gene products that might account for colon cancer evasion of immune attack and chemoradioresistance-induced apoptosis. METHODS: SW480 and SW620 cells were used for this experiment. Type 1 apoptosis was induced by CH-11. Type 2 apoptosis was induced by cisplatin and ionizing radiation. Apoptosis was determined by caspase-3 activity and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling. Gene products Fas, TRAIL, c-FLIP, Bid, BAX, Bcl-2, Bcl-xL, Apaf-1, nuclear factor-kappa B, Smac/DIABLO, apoptosis inducing factor, and the inhibitors of apoptosis were investigated by immunocytochemistry and Western blot analyses. RESULTS: SW620 cell lines were more resistant to both Type 1 and Type 2 apoptosis induced by CH-11, cisplatin, and ionizing radiation, respectively. Examination of the extrinsic pathway demonstrated Fas receptor to be down-regulated in SW620. Apaf-1 was decreased in SW620 cells; while other members of the mitochondrial pathway including Bax, Bid, Bcl-xL, and Bcl-2 demonstrated minimal alterations of protein levels in both cell lines. Survivin and XIAP protein levels were increased in SW620 cells, which correlated with nuclear expression of nuclear factor-kappa B in SW620 cells but not SW480. Mitochondrial-released factors including Smac/DIABLO and apoptosis inducing factor were increased in SW480 cells. CONCLUSIONS: SW620 cells have acquired genetic defects both in the intrinsic and extrinsic pathways of apoptosis, which may explain in part the ability of colon cancer cells to escape the immune system and to become chemoradioresistant. These genes may be potential targets for chemoradiosensitization in advanced colorectal cancer.     

Induction of tumor-specific cytotoxic T lymphocytes in cancer patients by autologous tumor RNA-transfected dendritic cells

OBJECTIVE: To demonstrate the feasibility of inducing tumor antigen-specific immune responses in patients with metastatic cancer using total tumor RNA-loaded dendritic cells (DCs). SUMMARY BACKGROUND DATA: The authors have shown that DCs transfected with mRNA encoding defined tumor antigens induce tumor antigen-specific T-cell responses in vitro and in vivo. There may be significant advantages to inducing immune responses against the entire repertoire of antigens expressed by a patient's autologous tumor. METHODS: RNA was extracted from a metastatic colon cancer and used to load autologous DCs. The DCs were coincubated with autologous T cells and the cytolytic activity of the T cells was assessed by the ability to lyse the autologous tumor cells. RNA was then extracted from a metastatic lung cancer and used to load autologous DCs, followed by four injections of the DC vaccine given every 4 weeks. Tumor antigen-specific cytotoxic T lymphocyte activity was then evaluated by testing peripheral blood mononuclear cells for their ability to lyse an antigen-expressing target. RESULTS: DCs transfected with the total RNA content of autologous tumor cells stimulated antigen-specific T-cell responses that are capable of recognizing and lysing autologous, primary tumor cells in vitro. Tumor-specific immune responses were induced in a patient with a carcinoembryonic antigen-expressing adenocarcinoma after immunization with autologous DCs transfected with total tumor RNA. CONCLUSIONS: DCs transfected with total tumor RNA may represent a method for inducing immune responses against the entire repertoire of tumor antigens of surgically resected malignancies.     

IL-18基因转染大肠癌细胞及对其肿瘤原性改变的研究

目的：建立转染人白细胞介素-18（hIL-18）基因的大肠癌细胞株,并研究IL-18基因转染后SW480细胞肿瘤原性的改变。方法：将携带hIL-18的质粒pcDNA3.1-hIL-18转导入人大肠癌细胞系SW480细胞中,通过药物G-418进行筛选,利用RT-PCR和ELISA法对IL-18的表达进行检测;通过裸鼠致瘤实验观察肿瘤原性的改变。结果：IL-18基因成功转导入SW480细胞中并能顺利表达;RT-PCR电泳结果显示IL-18基因在mRNA水平有表达;ELISA结果显示,106个转染细胞在24 h内分泌IL-18的含量是（145.71±4.42）pg;空载体转染的细胞未检测到hIL-18;生长曲线显示转染hIL-18基因后的细胞生长明显减慢;黏附曲线显示SW480-hIL-18组的黏附率在各个时相点均明显升高,而空载体组和空白对照组之间差异无统计学意义（P〈0.05）。裸鼠致瘤实验表明,接种SW480-hIL-18细胞的裸鼠肿瘤体积明显小于SW480组和SW480-pcDNA3.1组;抗瘤实验结果显示,放射灭活的SW480-pcDNA3.1细胞和SW480-hIL-18细胞免疫接种裸鼠后,再接种SW480细胞于裸鼠左侧背部皮下,SW480-hIL-18细胞免疫接种组肿瘤长出的时间比SW480-pcDNA3.1细胞免疫接种组明显延长,并且肿瘤的生长速度明显低于SW480细胞免疫接种组。结论：hIL-18基因能成功整合到SW480细胞基因组中,并且能在转染的肿瘤细胞中持续表达。hIL-18基因转导后的SW480细胞生长受到抑制,黏附能力增强h,IL-18基因转染降低了SW480细胞的肿瘤原性;hIL-18基因修饰的SW480细胞具有明显的抗肿瘤作用,为大肠癌基因工程肿瘤疫苗的研制提供了实验基础。     

Hyaluronan mediates adhesion of metastatic colon carcinoma cells

BACKGROUND: Hyaluronan (HA) is a cell-surface glycosaminoglycan that has been implicated in cancer progression. Cells isolated from metastatic colon carcinoma (SW620) produce greater amounts of pericellular HA than cells isolated from a primary tumor (SW480). Inhibition of hyaluronan synthases (HAS) by transfection with antisense cDNA decreases HA production. Because adhesion to the extracellular matrix (ECM) is required for invasion and metastasis, we hypothesized that pericellular HA mediates adhesion to ECM proteins such as laminin, collagen, and fibronectin and that inhibition of HA production or removal of HA by digestion with hyaluronidase would impair adhesion. MATERIALS AND METHODS: SW480, SW620, and antisense transfectants (SW620 cells transfected with vector alone, antisense HAS2, antisense HAS3, and both antisense HAS2 and HAS3) were assessed for adhesion to laminin, Type 1 collagen, or fibronectin-coated plates. To confirm that adhesion was mediated by HA, cells were treated with or without hyaluronidase prior to the assays. RESULTS: Metastatic SW620 cells adhered well to laminin; SW480 cells demonstrated 46% less adhesion (P < 0.05; Student's t test). SW620 cell adhesion to Type 1 collagen and fibronectin was >50% less than adhesion to laminin. Inhibition of HAS2 and/or HAS3 or pretreatment with hyaluronidase significantly decreased adhesion of SW620 cells to laminin (P < 0.05), suggesting that adhesion was dependent upon pericellular HA. CONCLUSIONS: Metastatic SW620 cells that produce large amounts of pericellular HA adhered well to laminin. Inhibition of HAS2 and/or HAS3 expression, or hyaluronidase digestion of pericellular HA significantly inhibited adhesion. These data suggest that HA promotes adhesion to laminin and may thereby facilitate invasion of the basement membrane and metastasis in colon carcinoma.     

In vitro induction of tumor-specific HLA class I-restricted CD8+ cytotoxic T lymphocytes from patients with locally advanced breast cancer by tumor antigen-pulsed autologous dendritic cells

BACKGROUND: Early dissemination of treatment-resistant tumor cells remains the major cause of metastatic recurrence and death in breast cancer patients. Dendritic cells (DCs) are the most powerful antigen-presenting cells, and recently DC-based vaccination has shown great promise for the treatment of human malignancies by immunological intervention. MATERIALS AND METHODS: CD8+ T lymphocytes derived from peripheral blood mononuclear cells stimulated in vitro with autologous breast tumor antigen-pulsed DCs were tested for their ability to induce a HLA class I restricted cytotoxic T lymphocyte (CTL) response against autologous tumor cells. To correlate cytotoxic activity by CTL with T cell phenotype, two-color flow cytometric analysis of surface markers and intracellular cytokine expression was performed. RESULTS: DC pulsed with breast tumor extracts consistently elicited a tumor-specific HLA class I restricted CTL response in vitro in three consecutive patients harboring locally advanced breast cancer. CTL expressed strong cytolytic activity against autologous tumor cells but did not lyse autologous Epstein Barr virus-transformed lymphoblastoid cell lines and showed variable cytotoxicity against the natural killer-sensitive cell line K-562. In all patients, two color flow cytometric analysis of surface markers and intracellular cytokine expression demonstrated that tumor-specific CTL exhibited an heterogeneous CD8+/CD56+ expression and a striking Th1 cytokine bias (IFNgamma(high)/IL-4 (low)). CONCLUSIONS: Tumor lysate-pulsed DCs can consistently stimulate specific CD8+ CTLs able to kill autologous tumor cells in patients with locally advanced breast cancer in vitro. Tumor antigen-pulsed DC-based vaccinations may be appropriate for the treatment of residual and/or chemotherapy-resistant breast cancer refractory to standard salvage treatment modalities.     

吉非替尼对结肠癌细胞的生长抑制作用与PTEN表达的关系

目的 观察表皮生长因子受体酪氨酸激酶抑制剂吉非替尼对人结肠癌细胞的生长抑制作用,探讨这种作用与结肠癌细胞PTEN表达的关系.方法 应用体外药物敏感实验检测吉非替尼对6种人结肠癌细胞系的生长抑制作用;应用RT-PCR检测不同结肠癌细胞中PTEN mRNA水平;应用Western blot 检测结肠癌细胞中PTEN蛋白表达水平.结果 吉非替尼在体外对6种结肠癌细胞系的生长抑制作用差异很大(F=325.51,P＜0.05).吉非替尼作用浓度为1 μmol/L时,Lovo细胞系抑制率达34%,对吉非替尼最为敏感,其半量抑制浓度(IC50)＜10 μmol/L;HT29和SW480为中度敏感(10μmol/L＜IC50＜100 μmol/L);而HCT116、LS174T和SW620不敏感,其IC50＞100 μmol/L.各个细胞系中PTEN mRNA和PTEN蛋白均有表达.结论 吉非替尼对结肠癌细胞的生长抑制作用与PTEN mRNA和PTEN蛋白表达水平无明显相关,即PTEN表达状态还不能作为预测结肠癌对吉非替尼敏感性的可靠生物学指标.     

转存活素基因树突状细胞抗消化道肿瘤的免疫效应

目的研究转染存活素基因对树突状细胞(DC)免疫功能的影响,观察修饰后的DC在体外诱导的抗消化道肿瘤免疫效应。方法脂质体介导存活素基因转染入DC,用蛋白印迹法检测培养上清存活素的表达,检测转存活素基因DC分泌细胞因子白细胞介素12(IL12)、肿瘤坏死因子α(TNFα)的功能,以及经流式细胞仪检测DC表面CD1a、CD83、MHCⅡ、CD80、CD86表达的高低,用噻唑蓝(MTT)法诱导人特异的细胞毒性T淋巴细胞(CTL)的能力。结果培养上清中均可以检测到存活素表达;转存活素基因DC的上清IL12、TNFα含量分别为(2652±327)pg/ml和(4371±835)pg/ml,比单纯DC组高(P<005);CD1a、CD83、MHCⅡ、CD80、CD86等在单纯DC表面低表达,在转基因DC表面高表达;MTT法检测,经转染存活素基因的DC提呈的细胞对胃癌细胞、结肠癌细胞、胆管癌细胞杀伤率分别为65%、77%、85%,而单纯DC杀伤作用较低。结论存活素基因转染修饰的DC能诱导细胞毒性T淋巴细胞的特异性,显著地提高DC的抗原提呈功能,体外能诱导高效而特异的抗癌免疫效应。     

CD44+-ESA+在结肠癌干细胞分选中的应用

目的 分选结肠癌细胞株SW480细胞中的CD133+-CD44+-ESA+亚群细胞,并观察其致瘤性.方法 用流式细胞仪分选SW480细胞中CD133+-CD44+-ESA+、CD133--CD44+-ESA+及CD133--CD44--ESA-亚群细胞.将这3组细胞分别接种于NOD/SCID小鼠,每组5只,观察肿瘤生长...