长非编码RNA LINC00941在结直肠癌中的表达及对细胞增殖的影响研究

为了研究与细胞分化相关的长非编码RNA(long non-coding RNA, lncRNA) LINC00941在肿瘤发生发展中的作用,通过实时荧光定量PCR技术检测LINC00941在6种不同类型的人类癌细胞和正常胚胎肾细胞HEK-293细胞中的表达水平,结果表明,LINC00941在结直肠癌细胞HCT116和HCT116 p53-/-、肺癌细胞A549和NCI-H1299、黑素瘤细胞Stilling中均有较高的表达水平,在结直肠癌细胞中表达水平最高. 以结直肠癌患者肿瘤组织和癌旁正常组织为材料,实时荧光定量PCR检测LINC00941的表达水平发现,肿瘤组织中LINC00941 RNA的表达水平显著高于癌旁组织. 通过shRNA(short hairpin RNA)干扰技术降低HCT116细胞中的LINC00941 RNA水平,导致细胞增殖速度下降,说明LINC00941与结直肠癌的发生发展相关.     

腺病毒介导MTS1的抑癌作用

人多肿瘤抑制因子（MTS1）是一个抑瘤基因,在许多原发性肿瘤及细胞系中都发现了它的突变,有潜在应用价值。由于腺病毒独特的性质,它介导的肿瘤基因置换疗法,受到了愈来愈多的应用与关注。人癌胚抗原启动子能指导组织特异性表达。将癌胚抗原启动子置于MTS1基因上游,并在下游加poly A化信号,通过穿梭质粒pΔE1SP1A在人胚肾细胞HEK 293中与腺病毒载体pBHG11进行同源重组,插入腺病毒E1区。获得的重组病毒粒子作用于人乳腺癌细胞系MCF7,初步表明重组腺病毒能抑制MCF7的生长。     

熊果酸对H22荷瘤小鼠抗肿瘤及免疫调节作用

目的 探讨熊果酸（UA）对H22荷瘤小鼠抗肿瘤作用及免疫功能的影响.方法 皮下移植建立H22荷瘤小鼠模型,腹腔注射不同剂量UA,检测抑瘤率和免疫器官指数,MTT法检测脾脏T、B淋巴细胞增殖能力,流式细胞术检测CD4＋、CD8＋T细胞亚群含量及比例,ELISA法检测血清细胞因子IL-2、IL-4和TNF-α的表达量.结果 UA对小鼠皮下移植性肿瘤H22有显著的抑制作用,可降低免疫器官中异常增大的脾指数,增强脾脏中T、B淋巴细胞增殖能力,提高淋巴细胞亚群CD4＋T细胞表达及CD4＋/CD8＋T细胞亚群比例,促进血清IL-2、TNF-α表达,降低IL-4表达.结论 UA可抑制小鼠肝癌H22肿瘤生长,体内可以提高荷瘤小鼠的免疫能力,其抗肿瘤作用可能与机体的免疫调节作用相关.     

Recombinant sTRAIL induces cell death of tumor cell lines as well as primary cancer cells

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a new member of TNF family. It was reported that TRAIL could induce apoptosis of tumor cells but not normal cells in tissue culture system. To further study the biological activity and potential clinical significance, a recombinant soluble TRAIL (rsTRAIL) has been expressed stably in E. coli after transformation of pET28b vector containing the extracellular domain of TRAIL. The yield of rsTRAIL is approximately as high as 60% of whole bacterial proteins. The rsTRAIL, purified by Ni+ -agarose affinity chromatography, could remarkably trigger apoptosis at the concentrations of 0.1-1 μg/mL in all 7 tumor cell lines tested in vitro. However, this killing activity has not been observed in mouse fibroblast cell line (NIH3T3) as normal control. Further investigation shows that the rsTRAIL could also kill primary tumor cells isolated freshly from patients with cardiac cancer, breast cancer and malignant thymoma, while the normal human peripheral blood lymphocytes are not killed under the same conditions. These results provide new evidence that rsTRAIL could induce apoptosis of tumor cells specifically and it could be a new promising medicine for tumor therapy.     

表达肿瘤抗原HPV-58 E7的HLA-A*0201阳性宫颈癌细胞模型的构建和鉴定

为建立内源性表达58型人乳头瘤病毒(Huamn papillomavirus type 58,HPV-58)重要癌抗原E7蛋白的HLA-A*0201阳性人宫颈癌细胞模型.以HPV-58全基因组为模板,采用PCR法扩增E7蛋白的编码基因,构建真核表达载体pEGFP-N2-HPV58E7;转化大肠杆菌DH5α,通过DNA测序鉴定质粒载体;经除内毒素纯化后,将大量制备的重组质粒瞬时转染293T细胞,采用RT-PCR和细胞免疫荧光方法研究重组质粒在人源细胞中的表达情况;最后,选择HPV检出阴性的HLA-A*0201阳性人宫颈癌C33A细胞株为宿主细胞,采用脂质体转染、G418抗性加压筛选和细胞克隆化培养技术,建立能够稳定表达HPV-58 E7的恒定转染细胞株.采用RT-PCR、Western-blot和细胞增殖测定等方法从转录、翻译和表型等3个层次对所建细胞株进行鉴定研究.研究结果显示:克隆制备了HPV-58 E7蛋白的编码基因;构建获得了能够在人源细胞中表达HPV58E7-EGFP融合蛋白的真核表达质粒;并成功建立了能够稳定表达HPV-58 E7的HLA-A*0201阳性人宫颈癌细胞模型;核酸和蛋白水平的鉴定结果表明所建模型细胞能够表达HPV-58 E7癌抗原,宿主细胞本身表达的Ⅰ类组织相容性抗原HLA-A*0201有望通过内源性抗原加工途径将E7抗原的细胞毒性T细胞(Cytotoxic lyphocyte,CTL)表位提呈到细胞表面;另外,细胞增殖试验结果亦表明该细胞模型体现出E7蛋白显著的诱导细胞增殖的生物学特征.总之,能够稳定表达HPV-58 E7癌蛋白的HLA-A*0201阳性人宫颈癌细胞模型的建立为后续即将展开的以HPV-58 E7为靶标的宫颈癌治疗性疫苗和药物的寻找和研究奠定基础.     

FBXO6稳定表达肿瘤细胞系的构建及其亚细胞器定位

检测FBXO6在多种肿瘤细胞中的表达和定位情况并构建稳定表达FBXO6的肿瘤细胞株。运用RT-PCR方法,在人胚肾293T细胞以及9种不同来源的肿瘤细胞中,检测了FBXO6的表达情况。以载体质粒pBabe-3Flag-FBXO6-puro/pBabe-3Flag-con、包装质粒pCMV-GAG-POL及包膜质粒pCMV-VSVG用Lipofectamine2000共转染包装细胞系293T,收集病毒颗粒感染A549细胞,经嘌呤霉素筛选稳定表达细胞株,Western blot鉴定FBXO6的表达。利用激光共聚焦荧光显微镜,采用间接免疫荧光方法,检测外源性FBXO6在A549中的亚细胞定位。在10种不同来源的细胞株中,FBXO6在A549细胞中的表达最高。成功筛选出嘌呤霉素抗性细胞系A549-Con与A549-3Flag-FBXO6。Western blot方法发现A549-3Flag-FBXO6细胞系稳定表达FBXO6蛋白。间接免疫荧光发现FBXO6与内质网tracker有共定位。FBXO6在肺癌A549细胞中高度表达,构建了稳定表达FBXO6的A549细胞系,部分FBXO6分布在内质网中。     

人肿瘤细胞株中细小病毒H—1的DNA扩增与非结构蛋白NS—1基因的表达

研究三株人癌细胞和两株对照细胞对细小病毒Ｈ－１杀伤作用敏感性的分子机制．表明了在感染复数ｍｏｉ（ｍｕｌｔｉｐｉｃｉｔｙｏｆｉｎｆｅｃｔｉｏｎ）为５ｐｆｕ（ｐｌａｑｕｅｆｏｒｍｉｎｇｕｎｉｔ）／细胞的情况下，作为Ｈ—１病毒复制受纳细胞的人肝癌细胞株ＯＧＹ－７７０３和人胃癌细胞株ＳＧＣ—７９０１，能够支持病毒ＤＮＡ扩增和非结构蛋白ＮＳ—１基因的表达，这和作为阳性对照的由ＳＶ４０转化的新生儿肾细胞株ＮＢ—Ｋ一样，但对Ｈ—１病毒感染有抗性的人肾癌细胞株ＯＵＲ—１０和它的对照人胎肾细胞株ＨｕＫ—１，并不支持病毒ＤＮＡ扩增和ＮＳ—１蛋白的表达．本文结果指出，细小病毒Ｈ—１的杀伤作用与细胞中的病毒ＤＮＡ扩增及ＮＳ—１基因表达的程度相关．     

Enhancement of T cell immune response to lymphoma cells by CD28/CD80 alternative pathway

The aim of this study is to determine whether myeloma and lymphoma tumor cells can function as efficient antigen presenting cells (APC) to enhance the co-stimulation of T cells. The expression and function of T cell activation-related molecules, especially CD80, CD28, CD40 and CD40 ligand (CD40L), were studied on nine human myeloma cell lines (HMCL) and two B lymphoma cell lines. In the case of myeloma cell lines, the cells generally lacked CD80 antigen and expressed a heterogeneous CD40, and the expressions of CD40 and CD80 molecules could not be induced by either CD28 stimulation or CD40 ligation. Conversely, in the two B lymphoma cell lines, tumor cells expressed both CD80 and CD40 to some extent. CD28 stimulation could obviously increase the expression of CD80, CD40 and some adhesion molecules, and therefore generate a more efficient anti- tumor cell immunity. In conclusion, CD28 stimulation combined with CD40 antibody or soluble CD40 ligand may be a promising immunotherapeutic approach to B lymphoma.     

Aberrant activity of Wnt/Frizzled signaling pathway in renal cancer cell lines

The expression ofWnt, Wntreceptor-Frizzled, and several other key components in Wnt pathway in renal cancer cell lines was studied. The result of semi-quantitative RT-PCR has shown that the expression level ofWnt5A andhFz5 mRNA were higher in renal cancer cell line (GRC-1) than in normal renal cell line (HK-2). This result has been confirmed byin situ hybridization. The expression of β-catenin protein was obviously higher in GRC-1 than in HK-2 (P< 0.01), but there were no different expressions of its mRNA between 3 lines. The reasons of the overexpression of β-catenin has been investigated by means of immunocytochemistry, SSCP and so on, no mutation ofβ-catenin gene and APC were found. That means that the overexpression ofWnt5A/hFz5 might be the reason of overexpression of β-catenin. It was concluded that the aberrant activity of Wnt pathway might play an important role in renal cell carcinoma.     

人类逆转录病毒的长末段重复序列（VRTVLTR）的表达与肺癌转移的关系

肺癌是最常见的恶性肿瘤之一。肿瘤癌很容易发生转移。实验以17例肺癌（5例肺腺癌、1例腺鳞癌、7例肺鳞癌及4例小细胞末分化癌）的原发灶、癌旁正常组织及转移淋巴结为材料,采用PCR及非放射性标记的RNA斑点杂交分析LTR在基因组的存在及其表达情况。研究结果发现：LTR序列在17例肺癌病人的正常组织及肿瘤组织的基因组中普遍存在,LTR致肺癌转移与其插入基因组中无关;LTR致肺癌转移与其表达增高有关,而且其高表达与小细胞肺癌的转移无关,而与非小细胞肺癌的转移密切相关。提示LTR参与了非小细胞肺癌的转移过程。实验结果为从细胞系获得的结论提供了进一步的证据。     

Z-ajoene induces tumor cells to die by apoptosis

To unravel the pharmacological actions of garlic, a simple thio-compound, z-ajoene, was purified from the fresh cloves. Three tumor cell lines were subjected to treatment with z-ajoene at different concentrationsin vitro and the morphological changes, DNA content of the cells and chromosome DNA fragmentation were observed by light microscopy, flow cytometry and agarose gel electrophoresis respectively. It was found that z-ajoene induced cell death by apoptosis in human HL-60 promyelocytic leukemia cells, MGc-803 gastric mucoid adenocarcinoma cells and Molt4 T lymphocyte leukemia cells. Western blot assay showed that z-ajoene Inhibited proto-oncogene bcl-2 expression in the three different kinds of tumor cells, suggesting that z-ajoene may be a potential agent for tumor chemotherapy.     

筛选p53靶向药物的细胞模型的构建

为了筛选可以恢复肿瘤细胞中p53功能的小分子,作者用表达野生型p53的人类直肠癌细胞HCT116建立了一株能够应答激活p53信号通路的荧光素酶报告基因的稳定细胞系,同时用表达野生型p53的人类骨肉瘤细胞U2-OS建立了一株能够应答激活p53信号通路的mCherry红色荧光蛋白报告基因的稳定细胞系.为了检测筛选p53靶向药物的有效性,利用三种已知的以p53为靶点的小分子药物(cisplatin,doxorubicin以及Nutlin-3)处理这两种稳定细胞系,结果显示p53信号通路在这两个稳定细胞系中均能够被激活.为了探索小分子RNA作为恢复p53功能的靶标药物,并进一步验证这两种细胞模型用于药物筛选的可行性,分别检测了MDM2和MDMX的5个不同shRNA.通过比较HCT116稳定细胞的荧光素酶活性和U2-OS稳定细胞中荧光蛋白的荧光强度,我们筛选出了有效沉默MDM2或MDMX的shRNA.数据表明,这两种细胞模型不仅可用作筛选激活p53的小分子化合物的平台,而且可用于筛选激活p53信号通路的小分子RNA.     

The apoptosis and cell cycle changes of SUD4 and DOHH2 induced by topotecan

Topotecan (TPT), a semisynthetic analogue of the natural product camptothecin is a cell cycle-specific drug with antitumor activity. To clarify the effect of TPT on SUD4 and DOHH2 cell line in this study, we examined the apoptosis and cell cycle changes of the two human cancer cell lines by exposing to TPT for 18 hours at various concentrations. The linear relationship between apoptosis cell number and the concentration of TPT was observed by means of Flow Cytometry and Annexin V assay. Then, DOHH2 cell is much more sensitive to TPT than SUD4 cell. In addition, Cell Question Software Assay showed positive relationship between the frequency of cells accumulated in S-phase and the concentration of TPT. The least concentration of TPT to change cell cycle is 5 nmol·L⁻¹ in both cell lines. These results suggest that the inducing apoptosis of cancer cells is one of mechanism of TPT antitumor activity. Feng Xiaorong: born in 1965, Post-doctoral Research Fellow, Engaging in Cell and Molecular Biology.     

Suppression of experimentally induced autoimmune encephalomyelitis by cytolytic T-T cell interactions

Down-regulatory phenomena have been described in several experimental models of tissue-specific, T-cell-mediated autoimmunity. For example, resistance to active induction of experimental autoimmune encephalomyelitis (EAE) can be induced by pretreating animals with non-pathogenic inocula of autoantigen or effector cells. Moreover, animals that have recovered from one EAE episode are resistant to subsequent induction of EAE. In some models, resistance to EAE has been transferred with immune cells to naive recipients. These experiments, which were based on transfers of unseparated immune cell populations, are difficult to interpret. Immune suppression circuits are known to be complex and involve various distinct cellular subsets. To further complicate the issue, resistance to EAE can be transferred not only by suppressor cells, but also by encephalitogenic effector cells injected in 'subclinical' doses. We describe now the isolation of homogeneous T lymphocyte lines from the spleens of Lewis rats that had recovered from T-cell-mediated EAE (tEAE) caused by the MBP-specific T cell line S1. These spleen-derived T line cells express the CD8 phenotype and specifically respond to determinants on the inducing S1 line, but not to the autoantigen MBP. Furthermore, the anti-S1 cells selectively lyse the encephalitogenic S1 T line in vitro and efficiently neutralize their encephalitogenic capacity in vivo.     

青龙衣的化学成分和抗肿瘤活性研究

研究青龙衣的化学成分及抗肿瘤活性.利用硅胶柱色谱和开放ODS柱色谱等分离技术从青龙衣的95%乙醇提取物中分离得到了11个化合物,通过理化性质、波谱数据分析等方法,鉴定了全部化合物结构.采用MTT法,选取人胃癌细胞株(SGC7901),人肝癌细胞株(Hep G2),人肺腺癌细胞株(A549),乳腺癌细胞株(MCF7),结肠癌细胞株(Lo Vo)对化合物体外抗肿瘤作用进行筛选.从青龙衣中分离鉴定了11个化合物,分别为正二十九烷醇(nonacosanol)(1),[1-(4'-甲氧基苯基)-7-(3'-甲氧基,2'-羟基苯基)-3',4'-环氧-3-庚酮[3',4'-epoxy-1-(4'-methoxylphenyl)-7-(3'-methoxyl-2'-hydroxyphenyl)-heptane-3-one](2),正三十一烷醇(hentriacontanal)(3),1-(4'-羟基苯基)-7-(3'-甲氧基-4'-羟基苯基)-庚烷-3-醇[1-(4'-hydorxyphenyl)-7-(3'-methoxy-4'-hydorxyphenyl)-hepta-3-ol](4),4,6-二羟基-3,4-二氢-1-萘酮(4,6-dihydroxy-3,4-dihydro-naphthalenone)(5),胡桃醌(5-hydroxy-1,4-naphthoquinone)(6),β-谷甾醇(beta-sitosterol)(7),齐墩果酸(oleanolic acid)(8),香草酸(vanillic acid)(9),槲皮素(quercetin)(10),香草醛(vanillin)(11).化合物5、10对肿瘤细胞均有很强的生长抑制作用,IC50≤35μmol/L.化合物8对肿瘤细胞有较强的生长抑制作用,IC50≤58μmol/L.化合物2、3、6和7对个别肿瘤细胞有作用,其他化合物对肿瘤细胞没有生长抑制作用.11个化合物均为已知化合物,其中化合物1,3,10,11为属内首分,化合物5、8和10均具有较显著的抗肿瘤活性.     

常见肝癌细胞系的转铁蛋白受体表达差异分析及主动靶向载体效率比较

转铁蛋白受体1(transferrin receptor 1,TfR1)可介导细胞内吞过程,从而摄取与之特异结合的纳米颗粒,因此成为许多主动靶向型纳米载体的靶点。研究表明,肝癌细胞存在TfR1高表达现象,可作为肿瘤治疗纳米药物递送系统的关键性靶点。体外评价是TfR1靶向纳米载体的重要研究环节,然而肝癌细胞模型种类繁多,其TfR1表达水平可能存在一定差异。选择了几种常见的肝癌细胞系,包括HepG2、Hep3B、MHCC97-H以及Huh-1,分别从mRNA水平以及蛋白水平测定了细胞系TfR1的表达情况,考察了转铁蛋白(Tf)以及转铁蛋白核酸适配体(transferrin nucleic acid aptamer, Tf-APT)对不同细胞的亲和效率。同时,制备了包载紫杉醇的TfR1靶向脂质体,并考察其对不同细胞系的细胞生长抑制作用。结果表明,4种肝癌细胞系在mRNA水平以及蛋白水平均存在TfR1的表达差异;同时,体外抗肿瘤结果显示,不同肝癌细胞系对紫杉醇-TfR1靶向脂质体的敏感性也存在显著不同。     

Ha-ras和Ki-ras癌基因转染和细胞对小鼠细小病毒杀伤敏感性的相关性(英文)

为研究Ha－ras和Ki－ras癌基因转染和细胞对小鼠细小病毒（MVM）杀伤敏感性间的关系，两个细胞株，即Ki－ras癌基因转化细胞株DT和Ha－ras癌基因转化细胞株REF4-3，被用来作为研究材料．体外细胞集落形成率和细胞在裸小鼠体内的成瘤能力测定显示，和对照细胞NIH／3T3相比，REF4－3和DT对MVM的杀伤作用更敏感．同时，DNA杂交和蛋白免疫沉淀实验结果也显示，在REF-3和DT细胞中，无论是MVM的DNA增殖能力还是其NS－1蛋白的表达能力，均较在其对照组NIH／3T3细胞中高很多．FACA测定也显示，在感染MVM30h后，S期细胞的比例在REF4－3和DT细胞中都有增加，而在NIH／3T3细胞中却略微减少．通过PCR方法也可发现，在受到MVM抑制的REF-3肿瘤中仍可检测到MVM的DNA．