腺病毒介导多基因对肝癌细胞凋亡的诱导作用

目的 研究腺病毒介导的多基因（ｐ５３、Ｂ７－１、ＧＭ－ＣＳＦ、ＩＬ－２）对肝癌细胞系调亡的诱导,及对肝癌细胞系裸鼠体内成瘤性改变的影响。方法 应用光镜、电镜和ＴＵＮＥＬ法,检测肝癌细胞系感染腺病毒介导的多基因后凋亡的发生,检测ＨｅｐＧ２细胞导入腺病毒多基因后裸鼠体内的成瘤性改变。结果 肝癌细胞系导入多基因后发生凋亡,并对化疗药物顺铂的敏感性增加,册时给予１０ｍｇ／Ｌ的顺铂,可使近３０％的肝癌细胞发     

野生型p53基因转移对血管内膜损伤后再狭窄的防治作用

为防止血管成形术后管腔再狭窄，我们构建了介导野生型ｐ５３基因转移的复制缺陷型重组腺病毒（Ａｄ－ｐ５３），将Ａｄ－ｐ５３感染日本大耳兔球囊损伤后的髂动脉，并通过携带ＬａｃＺ基因重组腺病毒感染观察基因转染效率。结果可见Ａｄ－ｌａｃＺ感染损伤后的动脉３天后血管内膜、中膜、外膜均有ＬａｃＺ基因的阳性表达；Ａｄ－ｐ５３感染损伤后的髂动脉２周后可见血管内膜增厚程度、内膜与中膜的比例明显减小，管腔狭窄程度明显减轻，ｐ５３蛋白大量表达，与对照组相比具有显著差异。证明野生型ｐ５３基因转移能明显抑制血管损伤后的内膜增殖，为野生型ｐ５３基因转移防治血管内膜损伤后再狭窄奠定了实验基础。     

重组反义c-myc 腺病毒对人胃癌细胞的体内及体外分子治疗

目的研究重组反义ｃｍｙｃ腺病毒对胃癌细胞的体内外生物学作用．方法采用ＬａｃＺ基因Ｘｇａｌ染色、ＭＴＴ,ＤＮＡ梯度降解试验、原位末端标记、流式细胞仪、ＰＣＲ分析、裸鼠致瘤性、裸鼠皮下移植瘤模型实验等方法,对反义ｃｍｙｃ重组腺病毒在人胃癌ＳＧＣ７９０１细胞系中的作用进行体内外研究．结果ＡｄＡＳｃｍｙｃ对ＳＧＣ７９０１细胞能产生明显的生长抑制作用,ＭＴＴ显示生长抑制率为４４１％．ＤＮＡ梯度降解试验、原位末端标记、流式细胞仪显示ＡｄＡＳｃｍｙｃ诱导了ＳＧＣ７９０１细胞凋亡．经ＡｄＡＳｃｍｙｃ处理的ＳＧＣ７９０１细胞裸鼠致瘤性消失．ＡｄＡＳｃｍｙｃ对裸鼠皮下移植瘤模型瘤内注射能有效降低肿瘤的生长速度,生长抑制率为６８９％．结论ＡｄＡＳｃｍｙｃ对胃癌细胞具有显著的体内外生长抑制及凋亡诱导作用     

腺病毒介导的人野生型p53、GM-CSF和B7-1基因转移诱导肝癌细胞的生长抑制和凋亡

目的 观察携带人野生型p53、GM－CSF和B7－1基因的重组腺病毒载体（BB－102）转染BEL－7402、HLE及HuH-7肝癌细胞后p53基因的表达,以及诱导肝癌细胞凋亡,影响肝癌细胞的增殖。方法 BB－102以MOI为50pfu/细胞感染肝癌细胞系BEL－7402（p53基因为野生型）、HLE及HuH-7(p53基因为突变型）。免疫组织化学法检测BB－102携带的p53基因的表达,TdT法原位检测肝癌细胞的凋亡。结果 BB－102携带的p53基因能在转染了BB－102的肝癌细胞中高效表达。转染BB－102后肝癌细胞生长明显受到抑制;染毒后第4－10d期间,BEL－7402、HLE及HuH-7三株肝癌细胞的平均受抑率分别为58．5％、81．5％及71．1％,其中对p53基因突变的肝癌细胞的抑制程度要大于对p53基因为野生型肝癌细胞的抑制程度。转染BB－102还能诱导肝癌细胞的凋亡。结论 BB－102通过其介导p53基因的表达抑制肝癌细胞的增殖,这为BB－102应用于肝癌的基因治疗提供实验依据。     

外源性野生型p53基因对人肺癌细胞生长的抑制

目的观察外源性野生型ｐ５３基因对有ｐ５３基因突变的人肺癌细胞系生长的影响。方法用多聚酶链反应单链构象多态性及ＤＮＡ测序，选择ｐ５３基因突变的人肺巨细胞癌系８０１Ｄ为受体细胞。构建野生型ｐ５３表达质粒ＰＺＩＰｎｅｏＳＶｐ５３。用基因枪介导外源基因。建立转染细胞系８０１Ｄｐ５３。用聚合酶链反应检测外源基因，观察转染细胞恶性生长的变化。结果转染细胞系８０１Ｄｐ５３体外长期传代有ｎｅｏ基因及外源ｐ５３基因存在，转染细胞生长明显受到抑制，克隆形成抑制率达９６％，裸鼠异种移植致瘤性降低，肿瘤生长明显缓慢。结论外源性野生型ｐ５３经基因枪导入有ｐ５３基因突变的人肺癌细胞后可长期存在于转染细胞中，且明显抑制转染细胞的恶性生长     

野生型p53对人肺癌细胞体内生长的抑制作用

观察外源性野生型ｐ５３基因对有Ｐ５３基因突变的人肺癌细胞系８０１－Ｄ体内生长的抑制作用。将转染了ｐ５３基因之细胞８０１－Ｄ－ｐ５３及转染ｐＺＩＰ之８０１－Ｄ－ｐＺＩＰ和母系细胞，接种裸小鼠皮下，以观察ｐ５３对癌细胞肿瘤源性的影响。瘤内注射或腹腔注射脂质体包裹的ｐ５３基因治疗荷人肺癌８０１－Ｄ细胞之裸小鼠，观察对肿瘤细胞体内生长的抑制作用。转染ｐ５３之８０１－Ｄ－ｐ５３细胞肿瘤源性显著降低，３／４移     

刺五加叶皂甙对动物实验性肝癌抑制作用的研究

目的　探讨刺五加叶皂甙（ Ａ Ｓ Ｓ）诱导肝癌细胞凋亡和抑制宿主肝癌生长和转移的作用,以寻找治疗肝癌的新途径。方法　给 Ｂ Ａ Ｂ Ｌ／ Ｃ 小鼠腹腔内注射 Ｈ ｅｐ Ｇ ２ 肝癌细胞,１０ ｄ 后给予 Ａ Ｓ Ｓ 腹腔注射,８ ｗ 后处死实验动物,取瘤称重,通过抑瘤率判断 Ａ Ｓ Ｓ 小鼠移植癌的抑制作用,流式细胞仪检测移植肝癌组织凋亡小体百分率。结果　当 Ａ Ｓ Ｓ 剂量为 ０２５ ｍ ｇ／ｋｇ 和 １ ｍ ｇ／ｋｇ时,抑瘤率分别为 ４５４３％ 和 ７２０６％ ,凋亡小体百分率为 ２０６±３９％ ,３１１±７８％ 。 Ａ Ｓ Ｓ 组腹膜、肝、肠系膜和脾的癌转移率显著低于对照组。结论　 Ａ Ｓ Ｓ 有抑制人肝癌在小鼠体内生长和转移的作用,其作用随剂量增加而递增,此作用可能与 Ａ Ｓ Ｓ 促进肝癌细胞凋亡有关。     

反义胰岛素样生长因子Ⅱ与胞壁酰二肽联合抗肝癌实验研究

目的：探讨反义胰岛素样生长因子Ⅱ（反义IGF－Ⅱ）与胞壁酰二肽（MDP）联合抗肝癌作用。方法：化学合成人IGF－Ⅱ5′端部分cDNA片段,克隆于真核表达体pcDNA3;将反义IGF－Ⅱ、MDP包裹于脂质体中,同时转导入体外培养HepG2人肝癌细胞株中、注射于裸鼠皮下人肝癌移植瘤内,观察两者联合应用对肝癌细胞生长的影响。结果：反义IGF－ⅡMDP时转导入体外培养的HepG2人肝癌细胞株后,细胞增殖处于停滞状态,同时注射于裸鼠皮下人肝癌移植瘤内,5只裸鼠中有2只肿瘤完全消散。结论：反义IGF－Ⅱ与MDP联合应用具有明显的抗肝癌作用。     

转化生长因子β1正,反义基因对人肝癌细胞SMMC—7721增殖的影响

目的探讨人转化生长因子β１（ＴＧＦβ１）正、反义基因对人肝癌细胞 ＳＭＭＣ－７７２１增殖的影响。方法将ＴＧＦβ１正、反义基因分别导入ＳＭＭＣ－７７２１细胞,观察各转染细胞生长情况、凋亡特征及Ｆａｓ、ｐ５３的表达。结果与空质粒转染细胞相比,正义ＴＧＦβ１基因转染细胞生长速度减慢,出现明显的细胞凋亡形态学改变,３－羟基末端标记法（ＴＵＮＥＬ）为阳性,而反义基因转染细胞未发生上述改变,两者都可检测到ｐ５３信号,但未检测到Ｆａｓ表达。结论ＴＧＦβ１可通过诱导ＳＭＭＣ－７７２１凋亡而对其生长起负调控作用,其机制可能与Ｆａｓ／ＦａｓＬ、ｐ５３无关。     

抗端粒酶核酶抑制肝癌细胞裸鼠移植瘤生长的研究

设计针对端粒酶RNA组分的特异性核酶，研究该核酶对肝癌细胞裸鼠移植瘤生长的影响。构建含针对端粒酶RNA组分锤头状核酶基因的重组真核表达质粒pBBS212-RZ，以及建立人肝癌细胞株HepG2裸鼠移植瘤模型。将不同剂量的pBBS212-RZ用脂质体包裹后进行瘤体内多点注射，对照组注射生理盐水或空质粒载体pBBS212。连续注射2l天后，测量移植瘤体积和重量，检测瘤组织端粒酶活性。抗端粒酶特异性核酶使瘤组织端粒酶活性下降(抑制率为72％)，明显地抑制了肝癌细胞裸鼠移植瘤生长(抑制率为68％)，且存在剂量依赖性。抗端粒酶特异性核酶作为一种有效的端粒酶抑制剂，可抑制肝癌细胞的生长，有望在肝癌基因治疗中发挥作用。     

Inhibition of autophagy significantly enhances combination therapy with sorafenib and HDAC inhibitors for human hepatoma cells

AIM:To clarify whether histone deacetylase inhibitors histone deacetylase inhibitors(HDACIs)can sensitize hepatocellular carcinoma(HCC)cells to sorafenib treatment.METHODS:Bax,Bcl-2,ATG5-ATG12,p21,and p27protein levels in Hep3B,HepG2,and PLC/PRF/5 cells were examined by Western blot.CCK8 and a fluorometric caspase-3 assay were used to examine cellular viability and apoptosis levels.The effect of Beclin-1 on sensitization of HCC cells to sorafenib was examined by transfecting Beclin-1 siRNA into Hep3B,HepG2,and PLC/PRF/5 cells.RESULTS:Autophagy inhibition enhances the inhibitory effects of vorinostat and sorafenib alone or in combination on HCC cell growth.Vorinostat and sorafenib synergistically induced apoptosis and cell cycle alterations.Western blot data indicated that HDACIs and Beclin-1 knockdown increased the p53 acetylation level.The knockdown of Beclin-1 enhanced the synergistic effect of the combination of vorinostat with sorafenib.CONCLUSION:HDACIs can sensitize HCC cells to sorafenib treatment by regulating the acetylation level of Beclin-1.     

腺病毒介导的p27kip1基因对胃癌细胞周期和DNA合成的影响

背景：近年来胃癌基因治疗的研究取得了一定的进展，但总体疗效尚不尽人意，目前正积极寻求组织特异性基因作为胃癌基因治疗的突破点。目的：以腺病毒为载体，研究p27kipl基因对胃癌细胞周期和DNA合成的影响。方法：将成功构建的携带人p27kipl基因的重组腺病毒载体Ad-p27kipl和LacZ重组腺病毒Ad-LacZ转染胃癌细胞系SGC-7901，并观察细胞形态的变化，流式细胞仪检测细胞周期和凋亡，^3H-胸腺嘧啶核苷(TdR)掺入实验测定细胞DNA合成。结果：Ad-p27kip1转染SGC-7901细胞后，细胞变圆、呈葡萄串样聚集以致脱落，G0／G1期细胞比例增加，8期、G2／M期细胞比例降低，并有凋亡发生，^3H-TdR掺入量亦显著降低。结论：腺病毒介导的p27kipl基因能使SGC-7901细胞产生G0／G1期阻滞，并能诱导细胞凋亡，抑制DNA合成，表明该基因疗法能有效抑制体外胃癌细胞的生长。     

Additive effect of Apo2L/TRAIL and Adeno-p53 in the induction of apoptosis in myeloma cell lines

OBJECTIVE: We have previously shown that Adenovirus-p53 (Ad-p53) is a potent inducer of apoptosis in myeloma cells expressing nonfunctional p53 and low levels of bcl-2 and that Apo2L/TRAIL is a potent inducer of apoptosis, independent of bcl-2. A study was designed to test the synergy between Ad-p53 and Apo2L/TRAIL in the induction of apoptosis in relation to the expression of DR4/DR5 and DcR1, in cells undergoing Ad-p53-induced apoptosis. METHODS: Replication deficient Ad-p53 and human recombinant Apo2L/TRAIL were used. Myeloma cells with mutated/w.t. p53 and varying expression of bcl-2 were used to test the effect of Ad-p53, Apo2L/TRAIL, or both, on apoptosis, measured by annexin V. RESULTS: Treatment with Ad-p53 resulted in a dose-dependent apoptosis concomitant with a dose-dependent increase in the expression of DR4/DR5 and a decrease in the expression of DcR1, in Ad-p53-sensitive cell lines. In these cells, addition of Apo2L/TRAIL to cells treated with Ad-p53 resulted in a dose-dependent increase in apoptosis. Myeloma cells resistant to Ad-p53 had high levels of DR4/DR5 and high levels of DcR1 and treatment with Ad-p53 did not reduce the expression of DcR1. Also, addition of Apo2L/TRAIL to Ad-p53 did not affect the level of apoptosis beyond the level of apoptosis observed with Apo2L/TRAIL alone. CONCLUSIONS: 1) Cotreatment with Ad-p53 and Apo2L/TRAIL resulted in additive apoptosis in myeloma cells expressing nonfunctional p53 and low levels of bcl-2. 2) Resistance to Ad-p53 or to the combination of Ad-p53 and Apo2L/TRAIL was not due to the lack of adenovirus receptor (CAR) or low expression of DR4/DR5 but rather due to the relatively high expression of DcR1 receptor.     

Antiangiogenic gene therapy for hepatocellular carcinoma using angiostatin gene

Recent studies have reported that antiangiogenic gene delivery into cancer cells inhibits growth of certain tumors in vivo. Hepatocellular carcinoma (HCC) is a hypervascular cancer, and antiangiogenic gene therapy might be suitable for HCC. In the present study, we investigated the antiangiogenic effects of angiostatin gene transduction into HCC both in vitro and in vivo. Angiostatin gene was cloned into a pSecTag2B mammalian expression vector to construct pSecTag2B-ANG. pSecTag2B or pSecTag2B-ANG were transfected into an HCC cell line, PLC/PRF/5, and then stable transfectants were obtained by Zeocin selection. pSecTag2B or pSecTag2B-ANG transfection did not alter the expression of vascular endothelial growth factor (VEGF), a potent angiogenic stimulator, or pigment epithelium-derived factor (PEDF), an angiogenic inhibitor, in PLC/PRF/5 cells. However, conditioned media (CM) derived from pSecTag2B-ANG-transfected PLC/PRF/5 cells (CM-ANG) suppressed the proliferation and migration of human umbilical vein endothelial cells (HUVEC) by 35% and 50%, respectively, relative to their effects on nontransfected cells. In in vivo experiments, pSecTag2B-ANG stable transfected (CM-Mock) and nontransfected cells (CM-N) were mixed at various proportions and the mixed cells were subcutaneously implanted into athymic mice. Suppression of tumor growth was noted in mice implanted with angiostatin gene-transfected cells, and such suppression was proportional with the percentage of transfected cells. Analysis of the vascular density in these tumors showed that the tumor growth suppression effect of angiostatin gene correlated with suppression of tumor vascularity. In conclusion, antiangiogenic gene therapy using angiostatin gene is potentially suitable for the treatment of patients with HCC.     

Synergetic anticancer effect of combined quercetin and recombinant adenoviral vector expressing human wild-type p53, GM-CSF and B7-1 genes on hepatocellular carcinoma cells in vitro

AIM: This study investigated the anti-cancer effect of combined quercetin and a recombinant adenovirus vector expressing the human p53, GM-CSF and B7-1 genes (designated BB-102) on human hepatocellular carcinoma (HCC) cell lines in vitro. METHODS: The sensitivity of HCC cells to anticancer agents was evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The viability of cells infected with BB-102 was determined by trypan blue exclusion. The expression levels of human wild-type p53, GM-CSF and B7-1 genes were determined by Western blot, enzyme-linked immunosorbent assay (ELISA) and flow cytometric analysis, respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyl transferase (TdT) assay or DNA ladder electrophoresis. RESULTS: Quercetin was found to suppress proliferation of human HCC cell lines BEL-7402, HuH-7 and HLE, with peak suppression at 50 micromol/L quercetin. BB-102 infection was also found to significantly suppress proliferation of HCC cell lines. The apoptosis of BB-102-infected HCC cells was greater in HLE and HuH-7 cells than in BEL-7402 cells. Quercetin did not affect the expression of the three exogenous genes in BB-102-infected HCC cells (P>0.05), but it was found to further decrease proliferation and promote apoptosis of BB-102-infected HCC cells. CONCLUSION: BB-102 and quercetin synergetically suppress HCC cell proliferation and induce HCC cell apoptosis, suggesting a possible use as a combined anti-cancer agent.     

The effect of adenovirus expressing wild-type p53 on 5-fluorouracil chemosensitivity is related to p53 status in pancreatic cancer cell lines

AIM: There are conflicting data about p53 function on cellular sensitivity to the cytotoxic action of 5-fluorouracil (5-FU). Therefore the objective of this study was to determine the combined effects of adenovirus-mediated wild-type (wt) p53 gene transfer and 5-FU chemotherapy on pancreatic cancer cells with different p53 gene status. METHODS: Human pancreatic cancer cell lines Capan-1(p53mut), Capan-2(p53wt), FAMPAC(p53mut), PANC1(p53mut), and rat pancreatic cancer cell lines AS(p53wt) and DSL6A(p53null) were used for in vitro studies. Following infection with different ratios of Ad-p53-particles (MOI) in combination with 5-FU, proliferation of tumor cells and apoptosis were quantified by cell proliferation assay (WST-1) and FACS (PI-staining). In addition, DSL6A syngeneic pancreatic tumor cells were inoculated subcutaneously in to Lewis rats for in vivo studies. Tumor size, apoptosis (TUNEL) and survival were determined. RESULTS: Ad-p53 gene transfer combined with 5-FU significantly inhibited tumor cell proliferation and substantially enhanced apoptosis in all four cell lines with an alteration in the p53 gene compared to those two cell lines containing wt-p53. In vivo experiments showed the most effective tumor regression in animals treated with Ad-p53 plus 5-FU. Both in vitro and in vivo analyses revealed that a sublethal dose of Ad-p53 augmented the apoptotic response induced by 5-FU. CONCLUSION: Our results suggest that Ad-p53 may synergistically enhance 5-FU-chemosensitivity most strikingly in pancreatic cancer cells lacking p53 function. These findings illustrate that the anticancer efficacy of this combination treatment is dependent on the p53 gene status of the target tumor cells.