淫羊藿苷与黄芩苷联合多柔比星对肝癌细胞APRIL表达和血管内皮细胞生长抑制的研究

目的:探讨中药单体淫羊藿苷(ICA)、黄芩苷(BAI)联合化疗药多柔比星(ADM)抑制肝癌HepG2细胞APRIL、VEGF的表达,进而抑制血管内皮细胞生长的作用机制.方法:MTT法检测血管内皮细胞ECV304的增殖活性;RT-PCR法检测HepG2细胞APRIL表达水平和ECV304细胞中APRIL受体HSPG的表达情况;免疫细胞化学检测HepG2细胞VEGF表达水平.结果:HepG2细胞中VEGF蛋白、APRIL和ECV304细胞中APRIL受体HSPG的mRNA均呈高表达状态,且APRIL与VEGF两者高表达呈显著正相关(P＜0.001);HepG2细胞经25 μg/mL ICA、200 μg/mL BAI、2 μg/mL ADM以及12.5 μg/mL ICA+1 μg/mL ADM、100 μg/mL BAI+1 μg/mL ADM 5组药物处理后,与未用药对照组相比,APRIL mRNA表达水平明显下降;HepG2细胞经5组药物处理后的上清液与未用药对照组相比,对ECV304细胞具有明显的增殖抑制作用,抑制率分别为(2.79±5.57)%、(15.20±3.79)%、(12.10±4.50)%、(19.34±8.17)%和(20.27±4.77)%(P均＜0.05);HepG2细胞经5组药物处理后,与未用药对照组相比,VEGF的表达水平明显下降.结论:APRIL具有促进静脉内皮细胞ECV304增殖的作用.ICA、BAI联合ADM能降低HepG2细胞中APRIL与VEGF的表达水平,从而发挥其抑制血管内皮细胞ECV304生长的作用.     

CD3AK/iNOS细胞对白血病细胞体外杀伤的研究

背景与目的:LAK细胞已用于临床移植物净化。CD3AK细胞是CD3单克隆抗体激活的杀伤细胞。本研究旨在经逆转录病毒介导iNOS基因转染人免疫活性细胞CD3AK建立CD3AK/iNOS细胞,并探讨其对白血病细胞株K562及其耐药株K562/ADM的杀伤作用。方法:培养PA317/pLNC-iNOS细胞获得病毒上清;CD3McAb联合小剂量的IL-2激活分离的外周血单个核细胞;含逆转录病毒颗粒的细胞培养上清感染靶细胞CD3AK细胞。测定CD3AK/iNOS、CD3AK细胞培养上清NO含量以及iNOS活性。MTT法观察CD3AK/iNOS、CD3AK对K562和K562/ADM细胞杀伤活性。结果:(1)CD3AK/iNOS、CD3AK中NO含量分别为(378.60±41.57)μmol/L,(98.07±22.31)μmol/L(P<0.001);CD3AK/iNOS、CD3AK中iNOS活性分别为(20.77±2.49)U/ml,(9.81±1.96)U/ml(P<0.001)。(2)MTT法观察CD3AK/iNOS对K562和K562/ADM杀伤活性分别为(64.85±18.13)%,(63.80±9.93)%。CD3AK杀伤活性分别为(45.66±17.46)%,(47.85±12.01)%。CD3AK/iNOS与CD3AK相比差异有显著性(P<0.05)。结论:CD3AK/iNOS分泌的NO含量、iNOS活性较CD3AK明显提高,且对K562及K562/ADM杀伤作用也更强;但CD3AK/iNOS对K562及K562/ADM杀伤作用无显著性差异。     

ICA,PJM逆转肿瘤细胞恶性表型及其机制的研究

目的:研究ICA,PJM逆转肿瘤细胞恶性表型,提高免疫效应细胞识别和杀伤的作用和机制。方法:MTT法检测ICA,PJM对PG细胞增殖的影响以及对CD3AK杀伤敏感性的影响;RT-PCR法检测ICA,PJM对bcl-2和c-fos基因mRNA表达水平的影响;流式细胞术检测细胞表面HLA-A,B,C抗原表达的变化以及c-fos,bcl-2蛋白表达水平的变化。结果:ICA,PJM对PG细胞有明显的增殖抑制作用,可以提高细胞表面HLA-A,B,C分子的表达和c-fos蛋白的表达,抑制bcl-2基因的表达,提高CD3AK细胞对PG细胞的杀伤活性。结论:ICA,PJM可以逆转肿瘤恶性表型,提高免疫效应细胞对肿瘤细胞的识别和杀伤。     

淫羊藿甙逆转转化生长因子β ２免疫抑制作用的抗肿瘤研究 *

研究淫羊藿甙(ICA)对PG细胞分泌转化生长因子β ２(transforming growth factor β ２,TGFβ ２)的影响、ICA逆转TGFβ2介导的免疫抑制作用及其机制。方法: MTT法检测细胞增殖、杀伤活性,RT-PCR检测TGFβ 2、穿孔素,流式细胞术检测TGFβ ２、IL-２Ｒα水平。结果: ICA可抑制PG细胞中TGFβ 2的蛋白和mRNA表达,能够逆转受TGFβ 2抑制的LAK和CD3AK细胞的杀伤活性,并能部分恢复受TGFβ ２抑制的LAK细胞表面IL-2Rα表达和CD3AK细胞内穿孔素mRNA水平,以及CD3AK细胞的增殖活性。结论: 淫羊藿甙通过抑制肿瘤细胞免疫抑制因子TGFβ 2的产生,增强免疫效应细胞的杀伤活性等机制而发挥抗肿瘤作用。     

顺氨氯铂,阿霉素增强人抗CD3单克隆抗体活化杀伤细胞的杀瘤效应

应用抗CD3单克隆抗体和基因重组人IL-2共同诱导人外周血单个核细胞，制备抗CD3单克隆抗体活化的杀伤细胞（CD3AK）。利用LDH释放法，观察顺氨氯铂（CDDP）和阿霉素（ADM）预处理人肝癌细胞系H－7402，对CD3AK杀伤该靶细胞的调节作用。ABC－ELISA法检测CDDP和ADM对H-7402细胞表达细胞间粘附分子-1（ICAM-1）、HLA－ABC、HLA－DR抗原的影响。结果表明：经CDDP（2．0μg／ml）、ADM（O．1μg／ml）预处理12h的H－7402细胞对CD3AK的杀伤敏感性显著提高（P＜0.05）；CDDP能够明显促进H－7402细胞表达ICAM-1、HLA－ABC分子（P＜0.05）；ADM预处理的肿瘤细胞表面三种分子的表达均未发生明显的变化。CDDP促进人肝癌细胞对CD3AK的杀伤敏感性可能与其上调了肿瘤细胞表面的ICAM-1分子有关。     

去甲斑蝥素对肝癌细胞增殖和凋亡的影响

目的:研究去甲斑蝥素(norcantharidin,NCTD)对人肝癌HepG2细胞增殖、凋亡和survivin表达的影响。方法:MTT法检测NCTD对HepG2细胞增殖的影响,Hochest33258染色、AnnexinV/PI染色、DNA琼脂糖电泳检测NCTD对HepG2细胞凋亡的影响,Western blotting检测NCTD对HepG2细胞survivin蛋白表达的影响。结果:NCTD可显著抑制HepG2细胞的增殖,呈质量浓度(5、10、20和40μg/ml)依赖性,40μg/ml NCTD作用48h时HepG2细胞抑制率达(81.27±3.25)%。NCTD作用HepG2细胞24h后,荧光显微镜下可见HepG2细胞出现核固缩和核裂解现象;DNA琼脂糖电泳显示,基因组DNA呈现典型的凋亡梯状图形;流式细胞术结果显示,5、10、20和40μg/ml NCTD作用后,HepG2细胞的凋亡率分别为(7.33±0.25)%、(18.23±1.19)%、(32.5±2.30)%和(48.23±1.17)%。Western blotting结果显示,随着NCTD作用剂量的增加,HepG2细胞中survivin蛋白的表达逐渐减少。结论:NCTD能抑制HepG2细胞增殖并促进其凋亡,其凋亡的发生与下调survivin蛋白的表达有关。     

姜黄素联合低浓度长春新碱抑制肝癌细胞系生长的实验研究

目的:研究姜黄素联合低浓度长春新碱对肝癌细胞系HepG2的生长抑制情况及可能机制。方法:实验设对照组(仅加培养基)、姜黄素组(20μmol/L)、长春新碱组(0.5、1、2、4μg/ml)及联合用药组(20μmol/L姜黄素+1μg/ml),各组作用HepG2细胞24 h后,采用细胞计数法测定细胞增殖情况,克隆形成实验检测各处理组的长期效应,DAPI染色测定细胞的死亡方式,线粒体膜电位检测细胞的线粒体损伤情况,流式细胞术检测细胞DNA含量及细胞周期阻滞,RT-PCR检测LRP、MDR1和P21 mRNA表达的变化。结果:与对照组和单独给药组比较,姜黄素联合长春新碱组经24 h处理后,明显抑制HepG2细胞增殖能力(P<0.05);克隆形成实验显示联合作用组明显抑制细胞集落形成能力;DAPI染色显示联合用药组凋亡细胞明显增加(P<0.01),线粒体膜电位测定显示联合用药组膜电位减低可能与凋亡率增加相关;流式细胞术测定联合用药组G2/M期阻滞显著增加(P<0.05);RT-PCR检测到LRP、MDR1 mRNA的表达降低(均P<0.05),而P21 mRNA的表达升高(P<0.05)。结论:姜黄素联合低浓度长春新碱町以显著抑制HepG2生长,为化疗新方案提供了一定依据。     

Synergistic tumor suppression by curcumin and low-concentration vincristine in hepatoma cell Lines

目的:研究姜黄素联合低浓度长春新碱对肝癌细胞系HepG2的生长抑制情况及可能机制.方法:实验设对照组(仅加培养基)、姜黄素组(20μmol/L)、长春新碱组(0.5、1、2、4μg/ml)及联合用药组(20μmol/L姜黄素+1μ g/ml),各组作用HepG2细胞24 h后,采用细胞计数法测定细胞增殖情况,克隆形成实验检测各处理组的长期效应,DAPI染色测定细胞的死亡方式,线粒体膜电位检测细胞的线粒体损伤情况,流式细胞术检测细胞DNA含量及细胞周期阻滞,RT-PCR检测LRP、MDR1和P21mRNA表达的变化.结果:与对照组和单独给药组比较,姜黄素联合长春新碱组经24 h处理后,明显抑制HepG2细胞增殖能力(P＜0.05);克隆形成实验显示联合作用组明显抑制细胞集落形成能力;DAPI染色显示联合用药组凋亡细胞明显增加(P＜0.01),线粒体膜电位测定显示联合用药组膜电位减低可能与凋亡率增加相关;流式细胞术测定联合用药组G2/M期阻滞显著增加(P＜0.05);RT-PCR检测到LRP、MDR1 mRNA的表达降低(均P＜0.05),而P21 mRNA的表达升高(P＜0.05).结论:姜黄素联合低浓度长春新碱可以显著抑制HepG2生长,为化疗新方案提供了一定依据.     

PHA-CD3AK细胞的体外诱导及其生物学特性初步研究

目的:研究PHA-CD3AK细胞的体外诱导方法及其生物学特性,并与LAK细胞进行比较.方法:分离人外周血单个核细胞(PBMC),采用植物血凝素(PHA)、单克隆抗体(anti-CD3McAb)和基因重组人白细胞介素2(rhIL-2)、共同诱导制备PHA-CD3AK细胞;应用流式法分析PHA-CD3AK细胞的免疫表型、乳酸脱氢酶法(LDH)检测PHA-CD3AK细胞的杀伤活性,并观察其形态;吉姆萨染色法观察其核型.结果:微量anti-CD3McAb(0.05μg/ml)辅以少量rhIL-2(300U/ml)和PHA(100μg/ml)共同培养,即能诱导和大量扩增PHA-CD3AK细胞,其扩增倍数显著高于LAK细胞,维持高扩增的时间也远较LAK细胞持久;当效靶细胞比为80:1时,PHA-CD3AK细胞对体外肿瘤细胞(K562)杀伤的百分率为56.5%;免疫表型检测PHA-CDB AK细胞中CD3+、CD4+、CD8+细胞的比率分别为(86.5±5.89)%、(38.20±5.27)%、(42.63±3.50)%;核型为正常二倍体,染色体数目为46条.结论:PHA-CD3AK细胞是以CD3+、CD4+、CD8+细胞为主的异质细胞群,并具有淋巴母细胞样特征,PHA-CD3AK细胞为正常二倍体细胞.PHA-CD3AK细胞是易于体外诱导、扩增能力强,体外存活时间长、杀瘤活性高的一种具有广阔应用前景的肿瘤过继免疫效应细胞.     

CD3AK细胞对人卵巢癌细胞系体外杀伤作用的实验研究

为研究卵巢癌盆腔引流淋巴结的淋巴细胞,经CD3单克隆抗体激活后的杀伤细胞CD3AK在体外的抗瘤作用.作者采用人卵巢癌病人盆腔引流淋巴结的淋巴细胞,在体外与CD3单抗和少量rIL-2诱导并激活后,在我所自建的两株人卵巢癌HO-891O、HO-89lOPM细胞系上进行了研究.两株细胞各随机分成6组:1)阴性对照组(A组):只加新鲜的全培养液 ; 2)低浓度CD3AK组(B组):5×10~5/ml CD3AK培养液;3)中浓度CD3AK组(C组):1×10~6/mlCD3AK培养液;4)高浓度CD3AK组(D组):2.5×10~6/mlCD3AK培养液;5)顺铂阳性对照组(E组):含10μg/ml顺铂的培养液;6)顺铂 CD3AK联合用药组(F组):含10μg/ml顺铂 1×10~6/mlCD3AK培养液,分别用LDH活性测定、自然杀伤率及台盼兰活细胞计数法观察结果.结果表明:CD3AK细胞对卵巢癌细胞有明显的杀伤作用,两株细胞均以中浓度CD3AK细胞     

Role of acidosis-sensitive microRNAs in gene expression and functional parameters of tumors in vitro and in vivo

Background: The acidic extracellular environment of tumors has been shown to affect the malignant progression of tumor cells by modulating proliferation, cell death or metastatic potential. The aim of the study was to analyze whether acidosis-dependent miRNAs play a role in the signaling cascade from low pH through changes in gene expression to functional properties of tumors in vitro and in vivo.Methods: In two experimental tumor lines the expression of 13 genes was tested under acidic conditions in combination with overexpression or downregulation of 4 pH-sensitive miRNAs (miR-7, 183, 203, 215). Additionally, the impact on proliferation, cell cycle distribution, apoptosis, necrosis, migration and cell adhesion were measured.Results: Most of the genes showed a pH-dependent expression, but only a few of them were additionally regulated by miRNAs in vitro (Brip1, Clspn, Rif1) or in vivo (Fstl, Tlr5, Txnip). Especially miR-215 overexpression was able to counteract the acidosis effect in some genes. The impact on proliferation was cell line-dependent and most pronounced with overexpression of miR-183 and miR-203, whereas apoptosis and necrosis were pH-dependent but not influenced by miRNAs. The tumor growth was markedly regulated by miR-183 and miR-7. In addition, acidosis had a strong effect on cell adhesion, which could be modulated by miR-7, miR-203 and miR-215.Conclusions: The results indicate that the acidosis effect on gene expression and functional properties of tumor cells could be mediated by pH-dependent miRNAs. Many effects were cell line dependent and therefore do not reflect universal intracellular signaling cascades. However, the role of miRNAs in the adaptation to an acidic environment may open new therapeutic strategies.     

Expression of thrombomodulin in astrocytomas of various malignancy and in gliotic and normal brains

Summary A total of 22 surgical specimens, 16 astrocytomas with various malignancy, 3 brains adjacent to tumor and 3 brains with non-neoplastic lesion, was investigated immunohistochemically for the expression of thrombomodulin (TM). This membrane protein is localized on the vascular endothelium of nearly every human tissue and plays a crucial role in the maintenance of antithrombotic property of the endothelial cells. Although the normal cerebral vessels were negative for TM, the tumor vessels were positive for TM. The increased expression of TM was, however, demonstrated not only in glioblastomas but also in low-grade astrocytomas. Furthermore, the vessels in the brains adjacent to tumor and gliotic brains were also positive for TM. Those observations suggested that the tendency of intratumoral bleeding, which is rather characteristic of glioblastomas, is not simply explained by the altered expression of vascular endothelial TM. In two cases of glioblastoma, not only the blood vessels but also the tumor cells were positive. Considering the mitogenic activity of thrombin, a ligand for TM, the increased expression of TM might be related to the tumor neovascularization and also the tumor growth.     

Synergistic anti-cancer effects of immunotoxin and cyclosporin in vitro and in vivo

Background:

The clinical use of immunotoxins (ITs) has been hampered by hepatotoxicity, and the induction of a strong human-anti-IT response. The human-anti-IT response results in neutralisation of the immunoconjugates, rendering repetitive treatment inefficacious.

Methods:

We evaluated the combination of cyclosporin A (CsA) with various Pseudomonas exotoxin A-based ITs in human breast, cervical, and prostate cancer cell lines measured by protein synthesis, cell viability, and TUNEL assay. Furthermore, expression of essential proteins were analysed by western blot. We used cervical cancer model in nude rats to evaluate the anti-metastatic effect of the combination. The anti-immunogenic response by the CsA treatment was investigated in immunocompetent rats.

Results:

The combination of CsA with ITs caused remarkable synergistic cytotoxicity, in several cancer cell lines, characterised by protein synthesis inhibition, decreased cell viability, and an increased apoptotic index. Furthermore, the combination strongly inhibited formation of metastases in a cervical cancer model in nude rats with a statistically significant increase in median survival time of the combination-treated animals, as compared with those receiving a suboptimal dose of IT alone. Notably, we found in immunocompetent rats that the anti-IT immunoresponse elicited by repeated administration of IT was efficiently abrogated by CsA; notably the antibody responds towards the highly immunogenic PE was shown to be prevented.

Conclusion:

The combination of ITs and CsA might constitute a significant improvement in the clinical potential of systemic IT treatment of cancer patients.     

Distribution and activity of transglutaminase in rat brain carcinogenesis and in gliomas

Tissue transglutaminase is a calcium-dependent enzyme which may influence cell morphology, cytoskeletal processes and membrane functions. During rat brain carcinogenesis induced by transplacental administration of N-ethyl-N-nitrosourea to BD IX rats, cytosolic tissue transglutaminase activity was increased by about 140% at 30 days of extrauterine life and returned towards the control values at 3–5 months. In the particulate fraction, enzyme activity progressively increased, reaching values similar to those present in the developed gliomas. Tissue transglutaminase activity in gliomas had a behavior inverse to that observed in controls, with a decrease (about 50%) in the cytosol and a marked increase (380%) in the particulate fraction, indicating a redistribution of enzyme activity.     

Occurrence of pathogenic fungi in soil of burrows of rats and of other sites in bamboo plantations in India and Nepal

This study examined 215 samples of soil from burrows of rats, other sites in bamboo plantations in different parts of India and Nepal by dilution plating and mouse passage technique for occurrence of Penicillium marneffei and other pathogenic fungi. None of the samples including 25 collected from the burrows of a bamboo rat (Cannomys badius) known to be a carrier of P. marneffei, was positive for the fungus. Among the pathogenic fungi recovered were four isolates of Pseudallescheria boydii (including one from Nepal), two of Trichosporon asteroides, one of Scytalidium hyalinum, 23 isolates of Trichophyton mentagrophytes var. mentagrophytes (including two from Nepal), and two of Microsporum gypseum. Fourteen of the 23 isolates of T. mentagrophytes var. mentagrophytes when tested with the mating types of Arthroderma vanbreuseghemii were found to be of the '+' mating type. The frequent recovery of this dermatophyte from soils of bamboo plantations in several parts of India is remarkable. The study also demonstrates for the first time the occurrence of P. boydii and T. mentagrophytes var. mentagrophytes in Nepalese soil. Among the other fungi recovered were several isolates of species of Aspergillus, Penicillium, Paecilomyces, Fusarium, Chrysosporium, Acremonium, Rhizopus, Mucor, Geotrichum, Trichosporon and Rhodotorula.     

ARHI在肿瘤发生和发展中的作用与机制研究进展

ARHI是1999年发现的母源性印迹基因,属于小G蛋白Ras超家族,是该家族第1个被报道的抑癌基因。ARHI的功能包括抑制小鼠生长和生殖发育,抑制细胞增殖、迁移,参与周期调控和凋亡,近年来研究发现ARHI还具有调控肿瘤细胞自噬、抑制肿瘤转移的作用。ARHI蛋白在人体卵巢、乳腺等多种组织中表达,在卵巢癌、乳腺癌、甲状腺癌、胰腺癌、肝癌组织中表达下调,ARHI基因高表达可提示卵巢癌、胰腺癌的预后良好。ARHI表达调控机制包括杂合性丢失、DNA甲基化、组蛋白去乙酰化、转录因子调节、miRNA和突变,应用表观遗传学技术调节ARHI表达可能在一些肿瘤中具有抗肿瘤临床应用价值。ARHI基因参与调节肿瘤细胞休眠过程,有望成为诱导肿瘤细胞休眠、抗肿瘤转移复发的关键点。     

促红细胞生成素及其受体在恶性肿瘤组织中的表达及功能的研究进展

促红细胞生成素(erythropoietin,EPO)最早被发现在红系细胞增殖、分化中发挥主要调节作用。研究发现在多种不同非造血器官及组织中有EPO及促红细胞生成素受体(erythropoietin receptor,EPO-R)的表达,并发挥促血管形成及组织保护效应。最近的多项研究发现,EPO及EPO-R广泛表达于多种恶性肿瘤细胞,EPO/EPO-R的自分泌/旁分泌通路与肿瘤微血管形成、刺激肿瘤细胞增殖、抑制凋亡及对放化疗的敏感性有关,确切机制需进一步研究。重组人促红细胞生成素(recombinant human erythropoietin,rh-EPO)在临床上已广泛用于治疗肿瘤相关贫血。研究证实其能增加血红蛋白水平,减少红细胞输注,同时改善患者生活质量。但亦有随机试验报道了rh-EPO治疗的患者相对安慰剂组患者无进展生存期下降。我们对EPO及其受体在非造血组织尤其是肿瘤组织中的表达、功能及相关机制的研究进展作简要概述。