黏蛋白1基因转染DC对乳腺癌细胞MCF-7裸鼠移植瘤的免疫抑制作用

目的:探讨黏蛋白1 (mucin 1,MUC1基因转染DC对人乳腺癌MCF-7细胞裸鼠移植瘤的抑制作用.方法:体外诱导培养健康成人DC,应用脂质体转染法将pcDNA3.1-MUC1转染DC,ELISA法检测转染后DC分泌细胞因子IL-12和YNF-α的能力,LDH释放法检测基因转染后DC诱导特异性CTL对乳腺癌MCF-7细胞的杀伤活性.应用MU C1基因转染DC、空质粒转染DC、及生理盐水皮下注射治疗人乳腺癌MCF-7细胞裸鼠移植瘤,观测其对肿瘤生长的抑制作用.结果:转染pcDNA3.1-MUC1的DC分泌IL-12、TNF-α的能力较转染空质粒DC明显增强[IL-12:(202.52±29.61)vs(10.83±1.02)pg/ml;TNF-α:(349.07±79.42)vs(9.26±1.52)pg/ml,均P＜0.01];转染pcDNA3.1-MUC1的DC诱导产生特异性CTL,对人乳腺癌MCF-7细胞具有更明显的杀伤活性,效靶比为10∶1、5∶1和2.5∶1时的杀伤率分别达到56.2％、38.9％和25.8％,显著高于对照组CTL(均P＜0.01).MUC1基因转染DC对乳腺癌MCF-7裸鼠移植瘤生长抑制作用明显强于空质粒转染DC组(P＜0.05).结论:MUC1基因转染DC可以诱导特异性CTL,对乳腺癌MCF-7细胞具有更强的抗肿瘤免疫效应.     

pEgr-TNFα基因联合放疗抑制食管癌细胞生长的实验研究

背景与目的研究pEgr-TNFα重组质粒在稳定转染的食管癌细胞中的辐射诱导表达,及其联合放射治疗抑制食管癌细胞生长的效果。材料与方法将脂质体包裹的pEgr-TNFα重组质粒,转染食管癌细胞系EC9706中,经G418筛选,获得稳定表达的细胞;采用ELISA方法检测0.075Gy和2Gy剂量X射线诱导后TNFα的表达;观察该工种剂量X射线照射后,EC9706细胞的增长情况。结果pEgr-TNFα重组质粒转染EC9706细胞,并获得稳定转染的细胞;大剂量X射线照射和低剂量X射线照射均可诱导TNFα表达增强,为对照组的6~6.3倍(P<0.01);稳定转染的细胞经0.075Gy和2Gy X射线照射,8d后细胞数明显低于未转染细胞组(P<0.01)和稳定转染的假照射组(P<0.01)。结论体外pEgr-TNFα基因-放射联合治疗有明显的抑制食管癌细胞生长的作用。     

超氧化物歧化酶、丙二醛和细胞因子在肺肿瘤患者中的表达

目的:探讨肺癌患者超氧化物歧化化酶(SOD)活性、丙二醛(MDA)含量、肿瘤坏死因子(TNF-α)和白细胞介素(IL-6))的变化及临床意义.方法:使用黄嘌呤氧化酶法、硫代巴比妥酸法和ELISA酶联免疫法测定了55例肺癌、33例肺部疾病及40例对照组血清中的SOD活性、MDA含量、TNF-α和IL-6水平.结果:肺癌患者SOD活性显著地低于对照组(P<0.05); MDA、TNF-α和IL-6则显著的高于对照组 (P<0.05);随治疗后,患者血清中的SOD活性逐渐增强;MDA、TNF-α和IL-6则迅速下降,临床症状得以缓解,其变化与肺癌的治疗效果与病情相关.结论:血清中SOD活性、MDA含量、TNF-α和IL-6水平可能与肺癌的发生、发展有关,测定这些指标可作为临床病情观察和监测疗效的辅助手段.     

pEgr-MDA7重组质粒辐射诱导特性的检测

背景与目的：克隆人MDA7 cDNA基因,构建pEgr-MDA7重组质粒并检测其在人食管癌细胞系EC9706中经辐射诱导后mRNA水平。材料与方法：从人外周血mRNA中克隆人MDA7 cDNA基因,连接到Egr-1启动子的下游构建成pEgr- MDA7重组质粒,利用脂质体介导转染人EC9706细胞,用定量PCR方法检测不同剂量X射线照射后被转染细胞中MDA7的mRNA水平。结果：测序结果证实MDA7 cDNA基因序列正确,酶切鉴定证实pEgr-MDA7重组质粒构建正确。被pEgr- MDA7重组质粒转染的人食管癌EC9706细胞经不同剂量X射线照射后,MDA7基因mRNA水平均高于未照射组。结论：X射线可诱导pEgr- MDA7重组质粒在人EC9706细胞中表达增强。     

B7-1基因转染小鼠EL-4淋巴瘤诱导带瘤宿主抗瘤效应的体内研究

本文研究了IL-2、IL-4、IL-6基因转染后B16黑色素瘤细胞表面MHCⅠ类抗原及ICAM-1的表达水平,并探讨了其在CTL诱导过程中的作用.结果表明,IL-2、IL-4、IL-6基因转染的B16黑色素瘤细胞表面MHCⅠ类抗原及ICAM-1表达均高于野生型B16黑色素瘤细胞及转染对照质粒的B16黑色素瘤细胞.体内接种后,小鼠脾脏CTL活性明显增强,CTL培养体系中IFN-γ、TNF-α的分泌水平也增高.在CTL诱导体系中加入抗ICAM-1单抗可以抑制CTL的活化,加入抗MHCⅠ类分子单抗后可使CTL的活化完全阻断.这提示细胞因子基因转染可能通过使肿瘤细胞表面MHCⅠ类抗原、ICAM-1的表达增加,从而增强瘤苗的免疫原性.     

IL-6基因转染的白血病细胞不同条件下体内外分泌IL-6水平的研究

我们将IL-6基因转染至FBL-3红白血病细胞,建立了高分泌IL-6的FBL-3-IL-6~ 细胞克隆株,并观察了不同照射剂量下其体外生长情况,IL-6分泌水平及不同途径接种人体内后血清和注射局部细胞培养上清中IL-6含量。将IL-6基因转染的FBL-3-IL-6~ 细胞调成1×10~5/ml浓度,分放于瓶中,置钴~(60)下分别照射不同剂量后,置5％CO_2中培养,观察其生长情况和半数死亡时间和全部死亡时间,并每日收集上清冻存待测IL-6。另外将高分泌IL-6的FBL-3-IL-6~ 细胞以2×10~5浓度分别通过腹腔和左股部皮下注入小鼠体内,并于不同时间取小鼠血清测IL-6含量(同时没对照组)。结果表明,当体外照射剂量<500Rad时,不能有效地控制白血病细胞的增殖能力,且于半个月中能保持较高水平的IL-6分泌量。所以当制备灭活的瘤苗时,以选用800Rad的钴~(60)照     

KiSS-1基因的表达对裸鼠子宫内膜癌皮下种植瘤的影响

目的探讨KiSS-1对子宫内膜癌转移抑制的效果及基因转染的方法和途径。方法将裸鼠分为对照组、空质粒转染组(空质粒与HEC-1B细胞同时注入裸鼠皮下)及KiSS-1质粒转染组(基因质粒与HEC-1B细胞同时注入裸鼠皮下)3组。成瘤后从解剖及组织学角度观察各组皮下瘤及转移瘤的体积和数量变化,从分子生物学水平检测pcDNA3.0-KiSS-1质粒在活体组织中的转染效果及表达水平,分析KiSS-1基因对肿瘤组织细胞侵袭转移能力的影响。结果用子宫内膜癌细胞株建立裸鼠皮下移植瘤是可行的,成瘤率为86%。KiSS-1质粒转染组较对照组及空转染组肿瘤细胞的KiSS-1mRNA表达明显增强,P=0.006。MMP-9mRNA表达明显减弱,P<0.05。实验组中肿瘤细胞KiSS-1mRNA的表达强度与转染pcDNA3.0-KiSS-1质粒的剂量有明确关系,P=0.05。结论建立子宫内膜癌裸鼠皮下种植瘤动物模型方法简单,成功率高,易于观察。KiSS-1基因体内转染方法可行,对细胞生物学影响与转染剂量有明确关系。KiSS-1基因可能是子宫内膜癌基因治疗的一个有前景基因。     

60Co照射对肿瘤坏死因子基因转导的人肝癌细胞的增殖及TNF-α分泌的影响

目的用60钴(60Co)照射肿瘤坏死因子基因转导的人肝癌细胞(BEL-7404-TNF细胞),用于制备一种肿瘤疫苗.方法用不同方式及不同剂量的60Co照射BEL-740-TNF细胞及未转基因的BEL-7404细胞,观察照射后细胞增殖情况及肿瘤坏死因子α(TNF-α)分泌量.结果经80Gy60Co连续分量照射的BEL-740-TNF细胞增殖能力丧失,但仍然生存并能持续分泌TNF-α2周以上,细胞在3周内全部死亡.结论用60Co照射BEL-7404-TNF细胞制备肿瘤疫苗是可行的, 80Gy60Co连续分量照射可能是合适剂量.     

肝细胞生长因子基因转染对阿霉素诱导胃癌细胞调亡的影响

目的研究肝细胞生长因子（HGF）基因转染对阿霉素诱导的胃癌细胞凋亡的影响。方法先构建HGF基因的真核表达质粒pIRES2-EGFP-HGF,应用pIRES2-EGFP-HGF重组质粒和pIRES2-EGFP空质粒转染人胃癌MKN-45细胞,以未转染组为对照。用转染细胞的培养液培养MDCK细胞后,以细胞形态学改变来分析目的基因mRNA、蛋白的表达,分别用RT-PCR、Western blot测定其功能。MTT法测定阿霉素对细胞生长的抑制作用,DNA凋亡条带法和PI染色法检测细胞凋亡。结果稳定转染HGF基因的MKN-45细胞株可表达HGF mRNA,其分泌的HGF蛋白具有正常功能。MTT检测表明,HGF质粒转染组活细胞数高于空质粒转染和未转染组。0．1μg／ml阿霉素作用细胞后DNA凋亡条带分析发现,空质粒转染及未转染组的MKN-45细胞出现典型阶梯状条带, HGF转染组细胞凋亡条带不显著。流式细胞术结果显示,HGF质粒转染组细胞凋亡率显著低于未转染及空质粒转染组。结论HGF基因稳定转染可显著抑制阿霉素诱导的胃癌细胞凋亡。     

HIF-1在TGF-β介导的ANGPTL4表达上调过程中的作用

目的 通过RNA干扰技术沉默A549细胞中乏氧诱导因子-1α(HIF-1α)的表达,初步探讨HIF-1在TGF-β介导的血管生成素样基因4(ANGPTL4)表达上调过程中的作用.方法 转染了HIF-1α-shRNA 的A549细胞(实验组)、转染空质粒的A549细胞(对照组)以及未转染的A549细胞(空白组)分别给予不同时间的TGF-β1干预,采用RT-PCR检测各组细胞中的HIF-1α与ANGPTL4的mRNA水平,Western blot检测各组细胞中HIF 1α与ANGPTL4蛋白的表达变化.结果 TGF-β1处理0、12、24、48 h后,相比于对照及空白组,实验组中HIF-1α与ANGPTL4的mRNA及蛋白表达水平显著降低(P＜0.05),且对照组及空白组中HIF-1α与ANGPTL4的mRNA及蛋白水平均与TGF-β1干预具有显著的时效相关性(P＜0.05).而实验组内HIF-1α与ANGPTL4未观察到上述变化趋势.结论 HIF-1可能是ANGPTL4的上游调控基因,并且参与TGF-β-Smad信号通路介导的ANGPTL4表达上调.     

人PTEN基因表达载体的构建及其在U251细胞中的表达

背景与目的:克隆人野生型和突变型PTEN的cDNA并构建其表达载体,探讨该表达质粒在人星形胶质瘤细胞U251中的表达情况.材料与方法:分别从新鲜胎盘组织和结肠癌组织中提取总RNA,采用RT-PCR的方法扩增人野生型和突变型PTEN基因全长cDNA,分别克隆入pMD 18-T载体上,经PCR、酶切鉴定均为阳性的克隆,进行核苷酸序列分析.再分别将两段基因定向克隆入pcDNA3.1( )载体中构建表达载体,转染入U251细胞.结果:成功克隆了人野生型及突变型PTEN cDNA并成功构建其表达载体,发现突变型PTEN蛋白对细胞生长无明显抑制作用,而野生型PTEN蛋白对细胞生长有明显抑制作用.结论:PTEN可能能抑制肿瘤细胞生长,为后进一步开展PTEN对肿瘤相关功能的研究奠定基础.     

Effect of green tea on p53 mutation distribution in ultraviolet B radiation-induced mouse skin tumors

In the present study, administration of green tea to SKH-1 mice, via the drinking fluid, was found to significantly reduce the incidence and volume of ultraviolet B (UVB) radiation-induced skin tumors. Thirty-six skin tumors induced by UVB and 32 skin tumors induced by UVB, in mice treated with green tea in their drinking water, were collected and examined for the presence of mutations in the p53 gene. Polymerase chain reaction products from p53 exons 5-8 were screened by single- strand conformation polymorphism and direct sequence analyses. Eight of 36 UVB-induced tumors contained nine p53 mutations, with four in exon 5 and five in exon 8. In contrast, nine of 32 UVB-induced tumors in mice treated with green tea contained 11 p53 mutations, with two in exon 5, five in exon 6 and four in exon 8. All of the p53 mutations occurred at dipyrimidine sequences. These results were further corroborated by p53 immunohistochemistry. The most frequent mutations were C-->T or T-->C transitions, which are consistent with the genetic alterations caused by UVB exposure. Interestingly, mutations found in exon 6 of the p53 gene occurred only in tumors from the UVB/green tea group. Thus, the tumors observed in UVB/green-tea-treated mice have a different exon distribution of p53 mutations than tumors obtained from mice treated with UVB alone.      

The role of orally administered dimethylarsinic acid, a main metabolite of inorganic arsenics, in the promotion and progression of UVB-induced skin tumorigenesis in hairless mice

The effect of dimethylarsinic acid (DMA) on skin tumorigenesis by UVB irradiation was examined. Hairless mice (Hos: HR-1) irradiated with UVB at a dose of 2 kJ/m(2) twice weekly, were fed with drinking water containing 1000 ppm DMA, a main metabolite of inorganic arsenics, produced more skin tumors than DMA-untreated mice. Histopathological examination revealed that the mouse malignant tumors with severe atypism appeared only in the treatment group of UVB plus 1000 ppm DMA. These positive results point out the importance of dimethylated metabolites of inorganic arsenic in the process of skin carcinogenesis.     

Chemopreventive effects of alpha-santalol on ultraviolet B radiation-induced skin tumor development in SKH-1 hairless mice

Recent studies from our laboratory have shown the chemopreventive effects of alpha-santalol against 7,12-dimethylbenzanthracene (DMBA) initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA) promoted skin tumor development in mice. The objective of the present investigation was to study the effects of alpha-santalol on ultraviolet B (UVB) radiation-induced skin tumor development and UVB-caused increase in epidermal ornithine decarboxylase (ODC) activity in female hairless SKH-1 mice. For the tumor studies, 180 mice were divided into three groups of 60 mice each, and each group was divided into two subgroups of 30 mice. The first subgroup served as control and was treated topically on the dorsal skin with acetone. The second subgroup served as experimental and was treated topically on the dorsal skin with alpha-santalol (5%, w/v in acetone). The tumorigenesis in the first group was initiated with UVB radiation and promoted with TPA; in the second group it was initiated with DMBA and promoted with UVB radiation; and in the third group it was both initiated and promoted with UVB radiation. In each case, the study was terminated at 30 weeks. Topical application of alpha-santalol significantly (P<0.05) decreased tumor incidence and multiplicity in all the three protocols, suggesting its chemopreventive efficacy against UVB radiation-caused tumor initiation, tumor promotion and complete carcinogenesis. In a short-term biochemical study, topical application of alpha-santalol also significantly (P<0.05) inhibited UVB-induced epidermal ODC activity. Together, for the first time, our findings suggest that alpha-santalol could be a potential chemopreventive agent against UVB-induced skin tumor development and, therefore, warrants further investigations.     

Direct and indirect modulation of ornithine decarboxylase and cyclooxygenase by UVB radiation in human skin cells

Exposure to solar ultraviolet (UV) B radiation is responsible for skin inflammation and tumour progression. Cyclooxygenase and ornithine decarboxylase are believed to be involved in such processes since they participate in the synthesis of mediators of inflammation and cell differentiation, respectively. We have investigated the in vitro modulation of expression of such genes by UVB radiation in different skin cell lines. We have observed that accumulation of ornithine decarboxylase mRNA is unaffected by even high UVB doses in both human epidermal keratinocytes and dermal fibroblasts, whereas cyclooxygenase-2 levels were significantly up-regulated by low UVB doses in KB human epidermoid keratinocytes. Depletion of total intracellular glutathione levels in KB cells amplified the activation, revealing a role for an oxidative component of UVB in modulating cyclooxygenase gene expression. Transfer of medium from UVB irradiated keratinocytes to fibroblasts resulted in a significant activation of cyclooxygenase expression and activity, while ornithine decarboxylase levels were unaffected. We conclude that UVB radiation can activate cyclooxygenase gene expression in human skin cells both by direct activation pathways or indirectly by inducing a paracrine mechanism.     

Role of p38 MAP kinases and ERK in mediating ultraviolet-B induced cyclooxygenase-2 gene expression in human keratinocytes.

The roles of p38 MAP kinases and ERK in UVB induced cox-2 gene expression were studied in a human keratinocyte cell line, HaCaT. UVB significantly increased cox-2 gene expression at both protein and mRNA levels. As we reported previously, p38 and ERK were significantly activated after UVB irradiation in HaCaT cells. In addition, treating the cells with p38 inhibitor SB202190 or MEK inhibitor PD98059 specifically inhibited UVB induced p38 or ERK activation, respectively. In this study, we further examined the roles of p38 and ERK in UVB induced cox-2 gene expression in HaCaT cells. We found that SB202190 strongly inhibited UVB induced COX-2 protein expression at different time points and various UVB doses. Furthermore, SB202190 markedly inhibited UVB induced cox-2 mRNA. Our data indicated that ERK did not play a role in UVB induced cox-2 gene expression in human keratinocytes since suppression of ERK did not significantly alter UVB induced increase of COX-2 protein and mRNA. These results suggested, for the first time, that activation of p38 is required for UVB induced cox-2 gene expression in human keratinocytes. Since cox-2 expression plays an important role in UV carcinogenesis, p38 could be a potential molecular target for chemoprevention of skin cancer.     

人COX-2基因反义真核表达载体对胃癌转移的影响

目的：在成功构建人COX-2基因反义真核表达载体的基础上,研究COX-2基因对人胃癌细胞株SGC-7901转移能力的影响。方法：实验分为COX-2基因反义真核表达载体转染的人胃癌细胞株SGC-7901转染组、COX-2抑制剂SC236处理组（SGC-7901细胞培养基内含100μmol/L SC236）和对照组（SGC-7901细胞）,并分别采用细胞体外侵袭实验,内皮细胞体外迁移实验,观察各组细胞体外转移的情况。采用裸鼠皮下移植瘤抑制实验,用转染和未转染的SGC-7901细胞按每毫升5×10~7个的细胞悬液分别注射于BALB/C-nu/nu无胸腺裸鼠背部皮下,SC236处理组按3mg/（kg·d）剂量于接种SCC-7901细胞10min后,由尾静脉注射,隔日1次。各组6周后处死动物,观察皮下移植瘤的生长情况。并用Western blot法检测各组细胞VEGF及MMP-2蛋白的表达。结果：体外侵袭实验、促内皮细胞体外迁移实验结果显示,与对照组相比,转染组和SC236处理组迁移的肿瘤细胞和内皮细胞均减少（P〈0.01）;裸鼠皮下移植抑制实验结果显示,转染组和SC236处理组荷瘤鼠移植瘤的生长受到抑制;Western blot结果显示,转染组和SC236处理组细胞VEGF及MMP-2蛋白的表达下降。结论：反义COX-2基因能抑制SCG-7901细胞的转移能力,其机制可能与其抑制肿瘤的血管生成、减少MMP-2的表达有关。     

Photocarcinogenesis in human adult skin grafts.

It has been demonstrated previously that the exposure to 7,12-dimethyl[a]benzanthracene (DMBA) and UVB radiation leads to the development of epidermal cysts, squamous cell carcinomas (SCC), melanocytic hyperplasia and melanoma in human foreskins from newborns grafted to immunodeficient mice. Improved techniques in grafting full-thickness skin from adults have enabled us to study photocarcinogenesis in human skin from different body sites and from older donors. One hundred and fifty-five normal white skin specimens from the trunk and face of 53 adult individuals were grafted onto severe combined immunodeficient (SCID) and recombinase activating gene-1 (Rag-1) knockout mice and irradiated two to three times weekly with 40 mJ/cm(2) UVB or solar-simulated UV (SSUV) over a period of up to 10 months with or without one prior topical application of DMBA. Over an observation period of 2-22 months, histopathological and immunohistochemical analyses of 134 specimens revealed actinic keratoses in 30% of the DMBA- + UV-treated grafts, in 18% of the grafts exposed to SSUV only, and in 10% of the grafts exposed to UVB only. Actinic keratoses were absent in grafts treated with DMBA only. One SCC was found in an abdominal skin graft 3 months after exposure to DMBA followed by UVB. Point mutations in codon 61 of the human Ha-ras gene were detected in the SCC, five of six analyzed actinic keratoses and in non-lesional epidermis of DMBA- and UVB-treated grafts, indicating that DMBA as well as UVB alone can induce these mutations in human skin. In contrast to the previous experience with neonatal foreskin grafts, melanocytic lesions were not found except for mild hyperplasia in few cases. The data suggest that melanocytes from young individuals are more susceptible to the transforming effects of genotoxic agents than melanocytes from adults.     

Effects of repeated low-dose UVB irradiation on the hyphal growth of Candida albicans

Ultraviolet B light (UVB) can have negative phototropic effects on fungi. Candida albicans is often found on human skin exposed to UVB. Therefore, it is of medical interest to know whether a negative phototropic response to UVB irradiation can support an invasive growth of this potentially dangerous agent. In our study we investigated how repeated irradiation with low doses of UVB can influence the hyphal growth of C. albicans. Six randomly chosen strains of C. albicans were tested. Formation of hyphae was induced and maintained within transparent agar plates. The fungi were exposed to UVB three times daily for 7 days from either the observe or the reverse side during incubation. The wavelength spectrum was in the range of 310-315 nm, single doses were between 0.0018 and 0.432 J cm(-2). After 7 days the morphology and growth direction of C. albicans cells were determined microscopically. All six strains showed a common and dose-dependent response to UVB irradiation: the progression of hyphal growth was inhibited, no phototropic effects were seen and as a new finding an increased formation of blastospores was observed. We conclude that an irradiation of human skin colonized by C. albicans with doses of UVB that can occur under natural or artificial conditions is unlikely to trigger skin invasion by C. albicans.