核酶抑制端粒酶活性的实验研究

目的为有效切割肿瘤细胞端粒酶ＲＮＡ组分使端粒酶活性降低,从而使细胞不能维持端粒长度而在有限分裂后进入凋亡。方法设计并合成了针对端粒酶ＲＮＡ组分的锤头状核酶基因,构建了该核酶基因的体外转录和真核表达质粒,检测了核酶对端粒酶ＲＮＡ组分的体外切割效力和对ＨｅＬａ细胞端粒酶活性的抑制效力。结果该核酶对端粒酶ＲＮＡ组分的体外切割效率达到６０％左右。导入ＨｅＬａ细胞后使端粒酶活性降至原来的１／８～１／１０,细胞生长速度明显变慢,传至１９～２０代时出现９５％凋亡。结论该核酶可望成为有效的端粒酶抑制剂,在肿瘤基因治疗中发挥作用。     

端粒酶核酶hTERT 5''RZ时辰治疗人肝癌裸鼠移植瘤

我们在既往的研究中 ,为探讨肝癌裸鼠移植瘤细胞DNA合成与端粒酶表达的生物节律 ,在时辰同步化裸鼠中构建了肝癌细胞SMMC 772 1裸鼠移植瘤。继续在程控光照条件下饲养 ,于光照后 3,6 ,9,1 2 ,1 5 ,1 8,2 1小时取样 ,用流式细胞仪测定各时期细胞DNA含量 ,细胞周期分布及端粒酶活性水平。结果 ,肝癌裸鼠移植瘤细胞DNA合成随昼夜节律变化 ,且伴随端粒酶活性的同步节律变化 ,均在光照后 2 1小时达高峰 ,光照后 9小时处于低谷 ;节律周期呈余弦分布。表明 ,肝癌裸鼠移植瘤的生长与端粒酶活性表达在静止相达高峰 ,为制定肿瘤时辰化疗方案提…     

封闭端粒酶活性对肺癌细胞系的生长抑制作用

目的　研究端粒酶反义核苷酸对肺癌细胞体内外生长的影响 ,探讨封闭端粒酶抑制肺癌细胞生长的可行性。　方法　端粒酶反义DNA与端粒酶阳性肺癌细胞系共同培养 ,观察其对肺癌细胞端粒酶活性、细胞形态和生长特性的影响 ;荷瘤小鼠肿瘤局部注射反义DNA ,初步观察其对动物体内肿瘤有无生长抑制作用。　结果端粒酶反义DNA对两个端粒酶阳性肺癌细胞系生长、集落形成有明显的抑制作用 ,细胞形态发生明显改变。注射反义DNA裸鼠肿瘤 ,瘤重明显低于生理盐水组 (P <0 0 5 )。　结论　端粒酶反义DNA序列对肺癌细胞系有明显的生长抑制作用。     

多基因共沉默治疗人喉鳞癌裸鼠移植瘤

目的 探讨针对血管内皮生长因子(VEGF)、端粒酶逆转录酶(TERT)、Bcl-xl的3个短发夹状双链RNA(shRNA)的串联表达质粒对人喉鳞癌裸鼠移植瘤生长抑制作用及其机制.方法 构建串联表达3个shRNA的质粒pEGFP-shVEGF-shTERT-shBcl-xl.建立人喉鳞癌Hep-2细胞系荷瘤裸鼠模型.将该质粒转染入荷瘤裸鼠瘤体内,观察肿瘤生长情况.荧光定量即时PCR检测三种目的 基因的mRNA在肿瘤组织中的表达情况,Western blot法检测三种蛋白的表达,原位末端标记法(TUNEL法)检测肿瘤细胞凋亡,免疫组织化学sP法检测肿瘤组织微血管密度.结果 与治疗前比较,质粒pEGFP-shVEGF-shTERT-shBcl-xl注射裸鼠皮下移植瘤后,肿瘤生长明显受抑制,治疗后14 d抑瘤率达91.2%.三个目的 基因的mRNA及蛋白表达水平比治疗前均有显著下降.移植瘤组织内检测到大量凋亡细胞,凋亡指数为(60.34±5.32)%.治疗组微血管密度明显低于生理盐水对照组及阴性质粒处理组.结论 pEGFP-shVEGF-shTERT-shBcl-xl能高效特异性地同时抑制3个靶基因在人喉鳞癌Hep-2细胞中的表达,增强基因沉默的多样性,并显著的抑制移植瘤的生长,提示未来应用多基因共沉默治疗喉鳞癌可能具有广阔的前景.     

脱氧核酶抑制鼻咽癌细胞EBV-LMP1的表达

目的 探讨l 0- 23脱氧核酶(1 0-23DR z)对鼻咽癌生长的抑制作用。 方法 设计合成针对EBV-LMP1的l0-23DRz，并对其进行硫代磷酸化修饰，同时针对该位点设计突变型DR z和反义寡核苷酸，经脂质体转染C666-1细胞中观察其对LMP1基因表达的抑制效应；建立裸鼠皮下鼻咽癌移植瘤，瘤体内注射脱氧核酶及其类似物，观察其对LMP1基因及肿瘤生长的抑制效应。 结果 有效转染后，脱氧核酶在细胞内抑制LMP1基因表达；成功建立裸鼠移植瘤模型后，脱氧核酶能高效抑制LMP1基因表达，并能抑制肿瘤生长，其作用较突变型脱氧核酶和反义寡核苷酸强（P<0.05）。 结论 脱氧核酶在鼻咽癌细胞中及移植瘤模型中都能高效抑制LMP1的表达，可能成为一种高度特异性的、高效的基因治疗剂。     

肝原位移植瘤裸鼠模型的建立及活体荧光成像检测

目的 建立能够通过活体荧光成像系统实时监测肿瘤进展的肝原位移植瘤裸鼠模型.方法 重组质粒pcDNA3.1-Luc转染细胞构建稳定表达荧光素酶的PLC/PRF/5肝癌细胞株,将该细胞注入裸鼠肝脏实质内,应用活体成像技术动态监测肿瘤进展情况,解剖荧光信号阳性裸鼠观察肿瘤组织生长情况.免疫荧光检测肿瘤组织中HBsAg表达.结果 对裸鼠肝原位移植瘤应用活体荧光系统成像,在肿瘤细胞注射部位检测到荧光信号,解剖动物后可在肝脏组织中观察到异质细胞团块.免疫荧光证实移植瘤中有HBsAg表达.结论 肝脏原位移植瘤裸鼠模型建立成功,为抗肝癌药物的研发提供了工具.     

抑制EGF-1受体表达对人鼻咽癌裸鼠移植瘤生物学行为的影响

目的诱导IGF-I受体基因沉默的shRNA真核表达质粒的在体抗瘤效应,探讨RNA干扰IGF-I受体基因对裸鼠人鼻咽癌移植瘤的生物学行为的影响。方法将右侧背部接种人鼻咽癌CNE2细胞后,肿瘤直径达5～7mm的24只裸鼠随机分为3组:A组为IGF-1RmRNA特异性真核表达质粒(pshRNA1)治疗组,瘤体内多点注射pshRNA1;B组为pshRNA2质粒载体对照组,瘤体内多点注射阴性质粒载体pshRNA2(剂量同A组);C组为生理盐水对照组,瘤体内多点注射0.3ml生理盐水。从开始治疗后3周处死裸鼠,分离肿瘤,部分做共聚焦观察质粒转染情况,其余肿瘤组织观察肿瘤组织的病理变化和IGF-I受体蛋白在瘤体内的表达变化。结果所有裸鼠移植瘤接种成功,14d左右肿瘤直径达5～7mm。治疗裸鼠7d后,pshRNA1治疗组抑制率达67.21%,瘤体积明显小于阴性质粒组和生理盐水组(P<0.05),阴性质粒组与对照组无显著差异。pshRNA1治疗组移植瘤可见大片癌组织表达绿色荧光,其中仅少数细胞为IGF-IR阳性细胞。阴性质粒组癌组织也表达绿色荧光,但IGF-IR阳性细胞数明显多于pshRNA1治疗组(p<0.05),而生理盐水组的移植瘤未见绿色荧光。结论shRNA干扰IGF-I受体基因能在体内有效下调IGF-I受体蛋白的表达、抑制鼻咽癌裸鼠移植瘤的生长。     

RNA干扰下调Stat5对人肝癌裸鼠移植瘤的抑制及诱导肿瘤细胞凋亡的研究

目的 探讨Stat5-shRNA对裸鼠体内人肝癌SMMC7721移植瘤的抑制及其诱导肿瘤细胞凋亡的作用.方法 将SMMC7721细胞悬液接种于裸鼠背部皮下,15d后,待在接种部位出现肿瘤结节、质地较硬等指标认定为成瘤.将15只成瘤裸鼠完全随机分为:空白对照组、HK质粒对照组、Stat5-shRNA组共3组,每组各5只.空白对照组瘤内注射生理盐水,HK质粒对照组瘤内注射Pgenesil1-HK,Stat5-shRNA组瘤内注射Pgenesil-1 -Stat5A1,各组注射剂量及次数均为50μl/只,每2天1次,共10次.第35天,处死各组全部动物,剥瘤称重,计算肿瘤大小及抑瘤率,流式细胞术检测肿瘤细胞凋亡情况.结果 与空白对照组和HK质粒对照组比较,Stat5-shRNA组裸鼠人肝癌移植瘤的生长受到明显抑制,肿瘤细胞凋亡率明显上升[(21.35±3.69)％比(3.56±1.12)％,(3.81±3.05)％,P＜0.05].结论 Stat5-shRNA可有效抑制裸鼠体内人肝癌移植瘤的生长,并能够诱导肿瘤细胞凋亡.Stat5-shRNA在人肝癌的基因治疗中具有潜在的应用价值.     

永生细胞株和肿瘤中人端粒酶RNA和端粒酶活性

人类和鼠类端粒酶活性在各种永生细胞株和肿瘤中呈正调节,它在永生细胞株和肿瘤组织中能检测到,而在原代细胞株和许多邻近肿瘤正常组织中缺乏。为了了解肿瘤发生期间端粒酶的调节,作者应用Northern印迹法和敏感的PCR为基础的端粒酶检测法分析了端粒酶活化期间近期克隆的端粒酶RNA组分(hTR)水平。结果发现端粒酶活性在原代     

Effector cells of low-dose IL-2 immunotherapy in tumor bearing mice: tumor cell killing by CD8+ cytotoxic T lymphocytes and macrophages.

The presence and cytotoxicity of tumor infiltrating cells is described in mice during effective immunotherapy with interleukin 2 (IL-2). DBA/2 mice were inoculated i.p. with 2 x 10(4) tumor cells on day 0 and treated with daily i.p. injections with 20,000 units IL-2 on days 10-14. Mice bearing a large syngeneic i.p. tumor burden (SL2 lymphoma, P815 mastocytoma, L5178Y lymphoma, or L1210 lymphoma) could be cured by i.p. immunotherapy with these low doses of IL-2. In the peritoneal cavity of these mice an infiltrate of mononuclear cells was present. Similar numbers of lymphocytes (10(6)-10(7)) and macrophages (+/- 10(7)) were present in control tumor bearing mice and IL-2 treated tumor bearing mice. The ratio of CD4+/CD8+ T lymphocytes in the peritoneal cavity of mice rejecting the SL2 tumor was smaller than 0.5, whereas this ratio is about 2 in naive mice. In the spleens of IL-2 treated tumor bearing mice only a minor decrease of CD4+/CD8+ ratio was observed from 2.1-2.4 to 0.9-1.9. T cells isolated from the peritoneal cavity of mice inoculated with SL2 tumor cells and treated with IL-2, were highly cytotoxic to SL2 cells: at E:T ratio 2:1 the cytotoxicity index was 37 +/- 3. This cytotoxicity was specific and mediated by CD8+ T lymphocytes. Macrophages that were present in the peritoneal cavity of mice treated with IL-2 were also highly cytotoxic. The C.I. of these cells was 63-76% at E:T ratio 1:1. Cytotoxic macrophages were also present in untreated tumor bearing mice. The i.p. injections of IL-2 (20,000 units/day) caused a four-fold increase in the local NK-activity in the peritoneal cavity in naive mice. These IL-2 injections did not generate LAK-activity in vivo. Specificity of the in vivo tumor rejection was tested by injection SL 2 i.p. on day 0 and P815 i.p. on day 10, or vice versa, followed by IL-2 treatment. Only the tumor cells that were injected on day 0 were rejected. These in vivo experiments point to specific tumor rejection. In conclusion, both cytotoxic macrophages and CTL's are present in a sufficient number and with sufficient cytotoxicity to explain the killing of tumor cells in the peritoneal cavity. The CTL-activity seems of decisive importance for tumor rejection as this is induced by IL-2.     

Antitumor activity of expanded human tumor-infiltrating gammadelta T lymphocytes

BACKGROUND: The objective of this study was to investigate the antitumor activity of selectively expanded gammadelta T cells in tumor-infiltrating lymphocytes (gammadeltaTILs) or tumor ascites lymphocytes (gammadeltaTALs) from patients with colorectal and ovarian epithelial carcinoma (OEC) in vitro and in vivo. METHODS: gammadeltaTILs/TALs were expanded by the solid-phase antibody method; their cytolytic and proliferative activities in vitro were detected by the MTT method and 3H-TdR incorporation and their effect in vivo was evaluated by the nude mice model. RESULTS: Expanded gammadeltaTILs from colorectal tumors demonstrated marked cytotoxicities to allogeneic human colon adenocarcinoma HR8348 and lymphoma Daudi cells, as well as xenogeneic murine thymoma EL-4 cell lines. Cytokines, including IL-2, IL-4, IL-12, IL-15, TNF-alpha and INF-gamma, could promote the cytotoxicities of gammadeltaTILs to tumor cells, whereas IL-10, GM-CSF and TFG-beta had no effect on such killing activities. Rested gammadeltaTILs could proliferate strongly in response to mitomycin C-treated Daudi and EL-4 tumor cells, but not to HR8348 tumor cells, suggesting that the latter might possess only cytotoxicity-related antigen recognized by gammadeltaTILs. Either alphabetaTILs or gammadeltaTILs from patients with OEC displayed cytotoxicities to allogeneic or autologous OEC cell lines at a similar strength in vitro. Transferring gammadeltaTILs into Daudi cell-bearing BALB/c nude mice with an injection of IL-2 was able to maintain a high survival rate of the mice for 30 days, when compared with mice treated with alphabetaTILs or without any treatment (p < 0.05). Without coinjection of IL-2, after 3 months of Daudi tumor inoculation, a high survival rate was observed in gammadeltaTIL-treated mice. Similarly, adoptive gammadeltaTALs from the ascites of patients with OEC transferred into nude mice displayed a stronger antitumor response to OEC SKOV3 cells than alphabetaTALs in vivo. Tumor volumes in gammadeltaTAL-treated mice were smaller than in alphabetaTAL-treated or non-TAL-treated mice within the period from day 23 to day 50 after tumor inoculation (p < 0.05). Fifty days after SKOV3 tumor inoculation, a decreasing trend of carcinogenic rate was observed in gammadeltaTAL-treated nude mice. CONCLUSION: Taken together, our results suggest that gammadeltaT cells could be a new candidate for adoptive immunotherapy in the future treatment of patients with cancer.     

Contribution of interleukin-11 and prostaglandin(s) in lipopolysaccharide-induced bone resorption in vivo

We previously demonstrated that interleukin-1 (IL-1) and tumor necrosis factor (TNF) activities only partially account for calvarial bone resorption induced by local application of lipopolysaccharide (LPS) in mice. The present study was undertaken to determine the role and relative contribution of IL-11 and prostaglandin(s) (PG[s]) in LPS-induced bone resorption in vivo. A one-time dose of LPS was injected into the subcutaneous tissue overlying calvaria of mice lacking IL-1 receptor type I (IL-1RI(-/-)), mice lacking TNF receptor p55 and IL-1RI (TNFRp55(-/-)-IL-1RI(-/-)), and wild-type mice. Mice were then treated with injections of anti-IL-11 monoclonal antibody (MAb), indomethacin, or phosphate-buffered saline (PBS) and sacrificed 5 days later. Histological sections stained for tartrate-resistant acid phosphatase (TRAP) were quantified by histomorphometric analysis. At low doses of LPS (100 microg/mouse), the percentages of bone surface covered by osteoclasts were found to be similar in three strains of mice. The increase was reduced by 37% with anti-IL-11 MAb and by 46% with indomethacin. At higher doses of LPS (500 microg/mouse), we found an eightfold increase in these percentages in wild-type mice and a fivefold increase in these percentages in IL-1RI(-/-) and TNFRp55(-/-)-IL-1RI(-/-) mice after normalizing with the value from the saline-PBS control group in the same strain of mice. The increase was reduced by 55 and 69% in wild-type mice and by 50 and 57% in IL-1RI(-/-) and TNFRp55(-/-)-IL-1RI(-/-) mice treated with anti-IL-11 MAb or indomethacin, respectively. Our findings suggest that in vivo, at low doses of LPS (100 microg/mouse), LPS-induced bone resorption is mediated by IL-11 and PGs, while at high doses of LPS (500 microg/mouse), it is mediated by IL-11, PGs, IL-1, and TNF signaling. IL-11 and PGs mediate LPS-induced bone resorption by enhancing osteoclastogenesis independently of the IL-1 or TNF signaling.     

Anti-neoplastic activities of sepia officinalis ink and coelatura aegyptiaca extracts against Ehrlich ascites carcinoma in Swiss albino mice

Objectives: With the development of sophisticated instruments for the isolation and elucidation of natural products structures from marine and freshwater organisms, major advances have been made in the discovery of aquatic derived therapeutics. Present investigations were carried out to evaluate cuttlefish (Sepia officinalis) ink extract (IE) and freshwater clam (Coelatura aegyptiaca) extract (CE) for their anticancer and antioxidant activities as compared to 5-flurouracil (5-Fu), in Ehrlich ascites carcinoma (EAC). Methods: Sixty female Swiss albino mice were divided into five groups (n = 12). All groups except group I received EAC cells (5 × 10⁶ cells/mouse i.p.) and this was taken as the 0th day. Group I served as saline control (5 ml/kg 0.9% NaCl w/v p.o). Group II served as EAC control. Rats of groups III, IV and V received IE, CE (200 mg/kg body weight i.p.), and reference drug (5-Fu, 20 mg/kg body weight i.p.), respectively. Results: The reduction in tumor volume, packed cell volume, tumor cell counts and increase in median survival time and percentage increase in life span in treated animals were observed. There was a significant increase in RBC count; Hb content in treated animals and reduction in total WBC count. There was a significant decrease in AST, ALT, ALP and liver MDA levels and increase in GSH, SOD and NO levels were observed in all treated animals. Conclusion: Both IE and CE were effective in inhibiting the tumor growth in ascitic tumor models. The biochemical, antioxidants and histopathological studies were also supported their antitumor properties.     

Lactoferrin peptide increases the survival of Candida albicans-inoculated mice by upregulating neutrophil and macrophage functions, especially in combination with amphotericin B and granulocyte-macrophage colony-stimulating factor

To develop a new strategy to control candidiasis, we examined in vivo the anticandidal effects of a synthetic lactoferrin peptide, FKCRRWQWRM (peptide 2) and the peptide that mimics it, FKARRWQWRM (peptide 2'). Although all mice that underwent intraperitoneal injection of 5 x 10(8) Candida cells with or without peptide 2' died within 8 or 7 days, respectively, the survival times of mice treated with 5 to 100 microg of intravenous peptide 2 per day for 5 days after the candidal inoculation were prolonged between 8.4 +/- 2.9 and 22.4 +/- 3.6 days, depending on the dose of peptide 2. The prolongation of survival by peptide 2 was also observed in mice that were infected with 1.0 x 10(9) Candida albicans cells (3.2 +/- 1.3 days in control mice versus 8.2 +/- 2.4 days in the mice injected with 10 microg of peptide 2 per day). In the high-dose inoculation, a combination of peptide 2 (10 microg/day) with amphotericin B (0.1 microg/day) and granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.1 microg/day) brought prolonged survival. With a combination of these agents, 60% of the mice were alive for more than 22 days. Correspondingly, peptide 2 activated phagocytes inducing inducible NO synthase and the expression of p47(phox) and p67(phox), and peptide 2 increased phagocyte Candida-killing activities up to 1.5-fold of the control levels upregulating the generation of superoxide, lactoferrin, and defensin from neutrophils and macrophages. These findings indicated that the anticandidal effects of peptide 2 depend not only on the direct Candida cell growth-inhibitory activity, but also on the phagocytes' upregulatory activity, and that combinations of peptide 2 with GM-CSF and antifungal drugs will help in the development of new strategies for control of candidiasis.     

Murine Stress-triggered Abortion is Mediated by Increase of CD8+ TNF-α+ Decidual Cells via Substance P

PROBLEM: Stress is known to induce abortions in mice and humans. Increased levels of abortogenic type 1 helper T-cell cytokines and decreased levels of pregnancy protective cytokines could be linked to stress-triggered embryonic loss. Stress promotes neurotransmitter substance P (SP) release in tissues. SP increases the production of decidual tumor necrosis factor (TNF)-alpha, whereby the phenotype of these TNF-alpha-producing cells is hypothetical. The objective of the present study was to identify decidual TNF-alpha-producing cell populations that are involved in stress-induced murine abortion. METHOD: DBA/2J-mated CBA/J female mice were exposed to ultrasonic sound stress on day 5.5 of pregnancy. The mice were randomized and half were treated with the SP NK1-receptor antagonist (SP-RA) RP 67580 (200 microg/mouse). Frequency and cytokine profile of CD8+ cells were evaluated by immunohistochemistry and flow cytometry. Degranulation of uterine mast cells was examined histologically. RESULTS: On day 13.5 of pregnancy, the uteri were removed and the resorption rate was calculated. A mean resorption rate of 38.4% was detected in stressed mice (n = 10) compared to 13.1% in non-stressed control mice (n = 11, P < 0.01). Injection of SP-RA decreased the abortion rate to 18.4% in stressed mice (n = 19, P < 0.01). Flow cytometry revealed a stress-related increase of TNF-alpha+/CD8+ decidual T cells, which could be abrogated by SP-RA (P < 0.05). No significant differences could be observed in numbers of mast cells and total CD8+ cells in situ. CONCLUSION: Our data suggest that stress-triggered abortion is mediated by SP, and SP receptor blockade abrogates stress-triggered abortion via reduced production of TNF-alpha by CD8+ T cells.     

Tissue-specific tumor suppressor activity of retinoblastoma gene homologs p107 and p130

The retinoblastoma gene family consists of three genes: RB, p107, and p130. While loss of pRB causes retinoblastoma in humans and pituitary gland tumors in mice, tumorigenesis in other tissues may be suppressed by p107 and p130. To test this hypothesis, we have generated chimeric mice from embryonic stem cells carrying compound loss-of-function mutations in the Rb gene family. We found that Rb/p107- and Rb/p130-deficient mice were highly cancer prone. We conclude that in a variety of tissues tumor development by loss of pRB is suppressed by its homologs p107 and p130. The redundancy of the retinoblastoma proteins in vivo is reflected by the behavior of Rb-family-defective mouse embryonic fibroblasts in vitro.     

Anti-malarial activity of leaf-extract of hydrangea macrophylla, a common Japanese plant

To find a new anti-malarial medicine derived from natural resources, we examined the leaves of 13 common Japanese plants in vitro. Among them, a leaf-extract of Hydrangea macrophylla, a common Japanese flower, inhibited the parasitic growth of Plasmodium falciparum. The IC50 of Hydrangea macrophylla leaf extract to Plasmodium falciparum was 0.18 microg/ml. The IC50 to NIH 3T3-3 cells, from a normal mouse cell line, was 7.2 microg/ml. Thus, selective toxicity was 40. For the in vivo test, we inoculated Plasmodium berghei, a rodent malaria parasite, to ddY mice and administered the leaf-extract of Hydrangea macrophylla (3.6 mg/0.2 ml) orally 3 times a day for 3 days. Malaria parasites did not appear in the blood of in the treated mice, but they did appear in the control group on day 3 or 4 after inoculation with the parasites. When leaf extract was administered to 5 mice 2 times a day for 3 days, malaria parasites did not appear in 4 of the mice but did appear in 1 mouse. In addition, the leaf-extract was administered orally 3 times a day for 3 days to Plasmodium berghei infected mice with a parasitemia of 2.7%. In the latter group, malaria parasites disappeared on day 3 after initiating the treatment, but they appeared again after day 5 or 6. Although we could not cure the mice entirely, we confirmed that the Hydrangea macrophylla leaf extract did contain an anti-malarial substance that can be administered orally.