恶性肿瘤自杀基因治疗中GCV和ACV体外抑瘤作用的比较研究

目的：用含有HSV-TK基因的重组腺病毒/丙氧鸟苷系统（AdTK/GCV)及该重组病毒/无环鸟苷系统（AdTK/ACV)，在体外分别对4种肿瘤细胞进行抑瘤实验，比较GCV、ACV对肿瘤细胞的抑制效果。方法：将同滴度AdTK感染的4种肿瘤细胞分别加入GCV、ACV，用MTT法测定OD值，计算细胞抑制率，用SPSS统计软件进行数据分析。结果：相同浓度的GCV与ACV相比，对肿瘤细胞的抑制率无显著差异。结论：由于ACV最大耐受量是GCV的4倍，且价格低廉，故在AdTK自杀基因治疗中可用ACV取代GCV。     

腺病毒介导融合双自杀基因治疗膀胱癌

目的 探讨腺病毒介导胞嘧啶脱氨酶（CD）和胸苷激酶（TK）融合双自杀基因系统对膀胱癌治疗作用并与单基因系统作比较。方法 利用含有CD-TK双自杀融合基因及绿色荧光蛋白（GFP）基因的复制缺陷腺病毒作载体,PCR检测CD、TK及E1基因。建立C57BL／6同系膀胱癌Mb49皮下移植瘤模型,观察肿瘤注射腺病毒联合丙氧鸟苷（GCV）或／和5-氟胞嘧啶（5-FC）治疗后肿瘤体积及组织学变化。结果 PCR可检测到腺病毒DNA中含CD及TK基因、无E1基因。腺病毒注射联合GCV、5-FC、GCV＋5-FC治疗后,肿瘤体积与对照组相比明显缩小（P=0.00）,腺病毒注射联合GCV＋5-FC有协同作用（P=0．04）,优于腺病毒注射联合GCV以及腺病毒注射5-FC。基因治疗后肿瘤细胞大片坏死．对照组细胞形态无变化。结论 腺病毒介导CD-TK融合双自杀基因联合GCV或／和5-FC能有效治疗膀胱癌,融合双自杀基因CD-TK／（GCV＋5-FC）系统对膀胱癌治疗有协同作用,其效果优于CD-TK／GCV或CD-TK／5-FC系统。     

腺病毒介导的双自杀基因系统对乳腺癌细胞的杀伤作用

目的 探讨腺病毒介导胞嘧啶脱氨酶(CD)和胸苷激酶(TK)融合双自杀基因系统对乳腺癌治疗作用.方法 用重组VEGFP-CD/TK-GFP基因的腺病毒体外感染表达VEGF的乳腺癌MCF-7细胞和对照组不表达VEGF的乳腺上皮细胞,荧光显微镜观察其感染效率,以RT-PCR检测受感染细胞CD/TK的表达,然后给子前药环氧鸟苷(GCV)和/或5-氟胞嘧啶(5-FC),用MTT法观察该体系对细胞生长增殖的影响;用流式细胞术观察细胞周期变化.建立MCF-7裸鼠皮下移植瘤模型,采用瘤内注射腺病毒载体联合腹腔内注射前药GCV和/或5-FC治疗后,观察肿瘤生长情况.结果 腺病毒对两种细胞的感染率相似,其感染率随腺病毒滴度的增高而递增.RT-PCR检测发现转染Ad-VEGFP-CD/TK的MCF-7细胞有目的 基凶的表达,而乳腺上皮细胞无表达.MTT法检测显示表达VEGF的MCF-7细胞对前药具有较高的敏感性,而不表达VEGF的乳腺上皮细胞对前药不敏感,CD/TK融合基因对MCF-7的疗效优丁任一单自杀基因(P＜0.01).在感染复数为100时,用流式细胞仪分析细胞周期显示治疗组细胞G0-G1期比率增多,S期细胞减少.在MCF-7裸鼠移植瘤模型中.该双自杀基因系统能够显著抑制肿瘤的牛长.其疗效优于任一单自杀基因(P<0.01).结论 腺病毒介导VEGF启动子驱动的CD/TK融合双自杀基因联合GCV和5-FC能有效治疗乳腺癌,其效果优于单自杀基因系统.     

腺病毒介导TK/GCV基因系统联合肿瘤坏死因子对膀胱癌细胞的体外杀伤作用

目的 研究腺病毒介导TK/GCV系统联合肿瘤坏死因子(TNF-?)对膀胱癌细胞的体外杀伤作用.方法 采用含有TK基因、绿色荧光蛋白(GFP)基因的复制缺陷腺病毒(adv )转染MB49细胞,观测转染率,RT-PCR检测转染细胞TK基因产物.以MB49细胞为对照,测定不同浓度TNF-?作用下MB49细胞、不同浓度GCV作用下MB49/TK细胞的存活率,采用GCV联合低浓度TNF-?对MB49/TK细胞进行体外杀伤研究;流式细胞仪检测TK/GCV、TNF-?、TNF-? TK/GCV对MB49细胞作用8 h后细胞凋亡情况.结果 随着浓度的增高GCV对MB49/TK细胞、TNF-?对MB49细胞的生长抑制率逐渐增高.GCV联合TNF-?对细胞杀伤率均较同浓度下单纯GCV及单纯TNF-?作用时的细胞杀伤率有明显增强,且随TNF-?浓度增高联合治疗组杀伤效率增强:单纯50 ?g/ml GCV组、5 ?g/ml TNF-? 50 ?g/ml GCV组、20 ?g/ml TNF-? 50 ?g/ml GCV组杀伤率分别(24.39±1.10)％、(40.05_ 0.97)％、(65.47±0.67)％.流式细胞仪检测细胞周期示TK/GCV、TNF-?、TK/GCV TNF-?组作用细胞8 h均可见典型sub-G1期细胞凋亡峰,联合作用组凋亡率最高.结论 TNF-?能明显增强TK/GCV自杀基因系统对膀胱癌的杀伤作用,两者联合能够有效促进膀胱癌细胞的凋亡.     

单链抗体导向的慢病毒介导VP22-TK系统对MUC1+人卵巢癌裸鼠腹腔移植瘤的作用

目的探讨抗MUC1单链抗体(scFv)导向的慢病毒介导的单纯疱疹病毒结构蛋白VP22和胸苷激酶(TK)融合基因及丙氧鸟苷(GCV)自杀基因系统对MUC1+人卵巢上皮癌的特异靶向性生长抑制作用.方法将慢病毒包装质粒、包膜质粒、转移载体质粒采用磷酸钙沉淀法共转染包装细胞293T,收集病毒上清,并建立MUC1+人卵巢上皮癌(3AO)细胞株腹腔移植瘤模型.单药组分为scFv-VP22-TK+生理盐水(NS)组、VP22-TK+NS组、NS+NS组,分别用慢病毒scFv-VP22-TK、VP22-TK或NS 1 ml腹腔注射,继予NS腹腔注射;联合用药组分为scFv-VP22-TK+GCV组、VP22-TK+GCV组、NS+GCV组分别应用慢病毒scFv-VP22-TK、VP22-TK及NS腹腔注射,24 h后给予GCV腹腔注射治疗.每组裸小鼠均为5只.观察各组裸鼠的生存时间及慢病毒的毒性作用.结果平均生存时间scFv-VP22-TK+NS组、VP22-TK+NS组、NS+NS组、NS+GCV组、VP22-TK+GCV组、scFv-VP22-TK+GCV组分别为18.4 d±2.9 d、18.8 d±1.5 d,17.6 d±1.1 d,18.5 d±1.6 d,24 d±5 d和46 d±22 d, 6组比较,差异有显著意义(χ2=24.82,P=0.002);并且scFv-VP22-TK+GCV组较VP22-TK+GCV组裸鼠平均生存时间明显延长(χ2=7.43,P=0.006).结论抗MUC1 scFv靶向的慢病毒介导的VP22-TK/GCV系统对MUC1+人卵巢上皮癌具有高效靶向杀伤作用.     

靶向性双自杀基因系统对脐静脉内皮细胞的杀伤作用

OBJECTIVE: To study the killing effect of adenovirus-mediated double suicide gene under the regulation of kinase domain-containing receptor (KDR) promoter on human umbilical vein endothelial cells (HUVECs). METHODS: The sequences of human KDR promoter gene, CD gene and TK gene were amplified by PCR, and the plasmid pKDR-CDglyTK was constructed. A two-step transformation protocol was employed for the construction of a recombinant adenoviral plasmid pAdKDR-CDglyTK that was transfected into 293 packaging cells to further multiply and purify the adenovirus. HUVECs were infected by the resultant recombinant adenovirus of different multiplicities of infection (MOI), and the infection rate was measured by observing the expression of green fluorescence protein (GFP). The infected cells were cultured in the culture media containing ganciclovir (GCV) and/or 5-fluorocytosine (5-FC) at different concentrations, and the killing effects were evaluated. RESULTS: Recombinant adenovirus AdKDR-CDglyTK were successfully constructed, which could efficiently infect HUVEC cells, with the infection rate associated with the MOI of the recombinant adenovirus. HUVEC cells infected with AdKDR-CDglyTK were highly sensitive to the prodrugs, their survival rate correlated to both the concentration of the prodrugs and the MOI of the recombinant adenovirus. The killing effect of the two produrgs used in combination was much stronger than that of exclusive use of GCV or 5-FC. CONCLUSIONS: Prodrug/KDR-CdglyTK system is effective in killing HUVEC cells, and its killing effect is correlated with the concentration of the prodrugs and the MOI of the recombinant adenovirus. Combination of the two prodrugs produces stronger killing effect on the cells.     

腺病毒介导的HSV-TK基因系统联合羟基喜树碱对人膀胱癌细胞的体外杀伤作用

目的 研究腺病毒介导的HSV-TK系统联合羟基喜树碱(HCPT)对人膀胱癌细胞的体外杀伤作用.方法 使用含有HSV-TK基因、绿色荧光蛋白(GFP)基因的复制缺陷腺病毒转染人膀胱癌细胞T-24细胞,表达GFP为转染成功标志,同时观察转染率,PCR检测TK表达.以正常T-24细胞为空白对照,转染成功后分别加入GCV、GCV HCPT,采用MTT法测定单纯HCPT作用于人膀胱癌细胞72 h细胞增殖抑制率、各组治疗转染后人膀胱细胞24、48、72 h细胞存活率;流式细胞仪检测GCV(0.5 mg/ml) HCPT(10 mg/L)作用T-24细胞4h后的凋亡情况.结果 随着浓度的增高,HCPT对T-24细胞的生长抑制率逐渐增高,HCPT浓度为0.01 mg/L时T-24生长抑制率为14%,50 mg/L时T-24生长抑制率为63%,当HCPT浓度大于100 mg/L时,抑制作用无明显增加(P=0.216).GCV组、GCV HCPT各组对转染后细胞有明显杀伤作用(P=0.00),GCV HCPT组随HCPT浓度增高和作用时间的延长,杀伤效率明显增高.0.5 mg/ml GCV单独作用于转染后的膀胱癌细胞72 h后,细胞存活率为34.6%,GCV(0.5 mg/m1) HCPT(10 mg/L)组的细胞存活率仅为8.07%(P=0.00).GCV 10 mg/mlHCPT作用后4h,T-24细胞出现M1期前典型的细胞凋亡峰,凋亡率达52.93%.结论 HSV-TK/GCV系统联合HCPT治疗能增强自杀基因系统对人膀胱癌的杀伤作用,能够良好地诱导人膀胱癌细胞的凋亡.     

腺病毒介导CDglyTK双自杀基因系统对裸鼠皮下移植瘢痕疙瘩的治疗作用

目的 探讨由大肠杆菌胞嘧啶脱氨酶(CD)基因/5-氟胞嘧啶(5-Fc)和单纯疱疹病毒胸苷激酶(HSV-TK)基因/丙氧鸟苷(GCV)基因治疗系统整合形成的腺病毒介导CDgly/TK双自杀基因系统对瘢痕疙瘩的治疗作用及其机制.方法 采用皮下移植保留表皮的入瘢痕疙瘩组织块的方法建立瘢痕疙瘩裸鼠模型,术后第7天将20只模型裸鼠分4组,每组5只.A组瘢痕内注射生理盐水;B组瘢痕内注射生理盐水+腹腔注射5-Fc和GCV;C组瘢痕内注射自行构建的莆组CDglyTK双自杀基因腺病毒(CDgly/TK);D组瘢痕内注射CDgly/TK+腹腔注射5-Fc和GCV;用药持续18 d.术后2、7(用药前)、14、21、28、35、42 d测量各组瘢痕疙瘩组织块体积;术后42 d取出瘢痕疙瘩组织块,HE染色进行组织学检查,末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法检测成纤维细胞凋亡情况,免疫组织化学染色检测Bcl-2、Bax蛋白质的表达.结果 用药前和用药后7、14、21、28、35 d,D组瘢痕疙瘩组织块体积(mm3)分别为173±5、172±5、147±5、125±6、112±7和84±9,从用药后14 d开始明显缩小(均P＜0.05);而其他3组瘢痕疙瘩组织块体积均明显增大,从用约后7 d开始各时点测得的体积均明显大于D组(均P＜0.05).D组瘢痕疙瘩组织中有大量小鼠组织细胞浸润,胶原结构破坏和成纤维细胞凋亡明显重于其他3组,Bcl-2蛋门质表达明显弱于而Bax蛋白质表达明显强于其他3组.结论 腺病毒介导的CDglyTK双自杀基因系统在瘢痕疙瘩裸鼠模型中对瘢痕疙瘩产生治疗作用,诱导成纤维细胞凋亡足其主要作用机制.     

核苷类似物对K562细胞的抗增殖和诱导分化作用

目的：探讨核苷类似物阿昔洛韦（ACV）,更昔洛韦（GCV）对人白血病细胞的抗增殖和诱导分化作用。方法：将ACV、GCV分别加入K562细胞培养4d,测定其活细胞数目,克隆形成率,联苯胺染色阳性率,观察光镜形态,组织化学染色,并进行流式细胞分析,端粒酶检测。结果：在ACV,GCV的作用下,K562细胞的增受抑,生长分数降低,并且向具有合成血红蛋白能力的细胞分化,结论：核苷类似物ACV,GCV对K562细胞具有抑制增殖和诱导分化作用,该结果为慢性粒细胞白血病的治疗提示了新的途径。     

逆转录病毒载体介导HSV-tk基因经尿道膀胱灌注对大鼠膀胱癌的杀伤作用

目的探讨经尿道膀胱灌注由逆转录病毒介导的HSV-tk基因对大鼠膀胱肿瘤的治疗作用.方法 N-甲基亚硝基脲(MNU)膀胱灌注诱导雌性Wistar大鼠膀胱肿瘤.经尿道HSV-tk基因膀胱灌注后,RT-PCR 检测肿瘤组织中tk基因表达;TUNEL 法检测肿瘤细胞凋亡;荷瘤膀胱总重量检测. 结果 HSV-tk基因经尿道膀胱灌注后,RT-PCR 检测膀胱肿瘤组织有tk 基因mRNA表达;TUNEL 法凋亡检测,荷瘤膀胱总重量测定,提示治疗组与对照组有显著差异.结论经尿道膀胱灌注逆转录病毒载体/HSV-tk可转导tk基因;联合GCV治疗,肿瘤生长被显著抑制;诱导肿瘤细胞凋亡可能是其作用机理之一.     

125IUdR治疗C6脑胶质瘤的实验研究

目的探讨125IUdR对脑胶质瘤的治疗作用. 方法体外采用细胞生长曲线测定、MTT法和集落形成试验观察125IUdR对C6脑胶质瘤细胞的作用;体内运用Wistar大鼠C6脑胶质瘤动物模型进行生存分析(肿瘤增殖高峰期局部缓慢三次注射药物,每天每次7.4×103 kBq.结果 125IUdR可显著抑制C6细胞体外增殖,具有时间和浓度依赖性.其中MTT法显示150 kBq/ml 125IUdR作用5 d后抑制率高达93.06%.而对照组Na125I和127IUdR对C6细胞体外增殖无明显抑制作用.125IUdR治疗胶质瘤C6大鼠5 d后,肿瘤重量低于空白组和对照组(P<0.01);生存分析显示空白组、127IUdR对照组和实验组的中位生存时间分别为9 d、12 d和27 d(P<0.01).结论根据肿瘤细胞增殖特征给药,125IUdR可显著抑制脑胶质瘤细胞增殖,延长脑胶质瘤C6大鼠生存期.     

单纯疱疹胸苷激酶/更昔洛韦系统杀伤前列腺癌细胞的"旁观者效应"及其调控

目的评价单纯疱疹胸苷激酶/更昔洛韦（HSV-TK/GCV）系统杀伤前列腺癌细胞PC-3m的“旁观者效应”,探讨连接蛋白（Cx）介导的细胞间隙连接交流（GJIC）在该系统“旁观者效应”中的作用,观察apigenin对PC-3m细胞连接蛋白43（Cx43）表达及GJIC状况的调控。方法MTT法评价TK基因系统杀伤PC-3m细胞的“旁观者效应”,划痕标记染料示踪技术（SLDT）比较几种代表细胞系GJIC功能状况,检测HSV-TK/GCV对其“旁观者效应”。逆转录－聚合酶链式反应（RT-PCR）法和SLDT检测PC-3m细胞Cx43表达和GJIC状况,并观察apigenin对Cx43表达、GJIC状况及“旁观者效应”的调控作用。结果HSV-TK/GCV系统杀伤PC-3m细胞时“旁观者效应”程度较弱,TK基因阳性细胞比例约为10%的混合细胞经100 μmol/L GCV处理72 h后,仅23.5%±3.21%细胞被杀灭。该自杀基因系统对GJIC功能强大的NIH-3T3、 Cos-7和L-02细胞“旁观者效应”程度远较GJIC功能低下的ACHN和HeLa细胞者强（P<0.001）。PC-3m细胞Cx43 mRNA表达降低,GJIC功能低下,apigenin不仅可上调PC-3m细胞Cx43表达、促进GJIC功能,还可使其“旁观者效应”明显改观（P<0.001）。结论细胞内在的GJIC功能与HSV-TK/GCV对其“旁观者效应”程度有正向关系,PC-3m细胞Cx43 mRNA表达减弱及GJIC功能低下可能是导致HSV-TK/GCV系统杀伤该细胞时“旁观者效应”较弱的原因,某些化学物质如apigenin可通过上调PC-3m细胞Cx43表达并促进GJIC功能,增强“旁观者效应”程度及TK基因系统疗效。     

胞嘧啶脱氨酶和单纯疱疹病毒胸苷激酶基因治疗肝门部胆管癌的体内外实验研究

目的:观察逆转录病毒介导的胞嘧啶脱氨酶(E.coli-cytosinedeaminase,CD)基因、单纯疱疹病毒胸苷激酶(herpessimplexvirus-thymidinekinase,HSV-tk)基因转染肝门部胆管癌的作用。方法:在脂质体lipofectamine的介导下将含有双自杀基因的逆转录病毒载体PWZLneoCDglytk导入包装细胞PA317,收集其病毒上清,转染FRH细胞,用RT-PCR检测双自杀基因的表达。给予前体药物5-氟胞嘧啶(5-flourocytosine,5-Fc)和(或)无环鸟苷(ganciciovir,GCV)后,用四甲基偶氮唑蓝比色(MTT)法测定转基因组及未转基因组FRH细胞存活率。在0.8cm裸鼠肝门部胆管癌模型转染入双自杀基因后,给予5-Fc500mg/kg体重,GCV100mg/kg体重,1次/d,共10d,观察肿瘤生长情况。结果:双自杀基因在FRH细胞中可稳定表达,联合使用5-Fc和GCV对靶细胞增殖的杀伤作用及旁杀伤效应高于单独使用5-Fc或GCV。在裸鼠实验性肝门部胆管癌,实验组肿瘤的生长明显受到抑制(P<0.05);双自杀基因与单自杀基因的作用有显著差异(P<0.05)。结论:逆转录病毒介导自杀基因可有效地杀死肝门部胆管癌细胞,明显抑制裸鼠肝门部胆管癌生长,双自杀基因共表达较单一自杀基因有更强的抗肿瘤作用。     

Killing effect of coexpressing cytosine deaminase and thymidine kinase on rat vascular smooth muscle cells

Background Vascular smooth muscle cell (VSMC) proliferation following arterial injury plays a critical role in a variety of vascular proliferative disorders, such as atherosclerosis and restenosis after balloon angioplasty. Herpes simplex virus-thymidine kinase (HSV-TK)/ganciclovir (GCV) and E.coli cytosine deaminase (CD)/5-fluorocytosine (5-Fc) suicide gene systems have been successfully employed in cardiovascular gene therapy, respectively. We reasoned that coexpression of both HSV-TK with CD suicide genes would lead to increased cell killing. To test this imagine, the adenoviral vectors expressing TK and/or CD genes were developed and tested on vascular smooth muscle cells. Methods Adenoviral vectors, including Ad-EF1α-CD-cytomegolovirus (CMV)-TK coexpressing both CD and TK double suicide genes, Ad-EF1α-CD and Ad-CMV-TK expressing CD and TK respectively, and control vector Ad-CMV-LacZ, were constructed and prepared with homologous recombination in RecA+E.coli cells. Integration and expression of CD and/or TK gene were identified by PCR and Western blot. Primary cultured VSMCs were infected at a multiplicity of infection (MOI) of 20 with exposure to their matching prodrugs 5-Fc and GCV. Cell mortality was measured by methyl thiazolyl tetrazolium (MTT) assays. Flow cytometry analysis was used to detect cell death. Apoptotic cells were analyzed using Hoechst 33342 fluorescence dye as a DNA probe. Genomic DNA cleavage of apoptotic VSMCs was tested by agarose gel electrophoresis. Results Recombinant adenovirus expressing CD and/or TK suicide genes were successfully constructed. Both single and double suicide genes could be integrated into adenoviral genome and expressed. Cytotoxic effects of Ad-EF1α-CD-CMV-TK double suicide genes combined with 5-Fc and GCV were higher than those of Ad-CMV-TK and Ad-EF1α-CD single gene groups. The rate of cell survival was only (9±3)% in the Ad-EF1α-CD-CMV-TK group, but (37±3)% in the Ad-CMV-TK and (46±4)% in the Ad-EF1α-CD groups (P&lt;0.05). Flow cytometry analysis indicated that the killing mechanisms of the groups were different. Necrosis and apoptosis were involved in the mechanism of the double gene group. Based on the DNA stainability with Hoechst 33342, the apoptotic rates of VSMCs in the Ad-EF1α-CD-CMV-TK ［(11.0±2.1)%］ and Ad-CMV-TK ［(12.0±2.2)%］ groups were higher than those in Ad-CMV-LacZ ［(1.2±0.11)%］ and Ad-EF1α-CD ［(5.0±1.8)%］ groups (P&lt;0.05, respctively). DNA smear could be observed in both Ad-CMV-TK and Ad-EF1α-CD-CMV-TK groups after administration of prodrugs. Conclusions The killing effect on rat VSMCs mediated by adenoviral CD/TK double suicide genes is superior to that of single suicide gene. The killing mechanism of recombinant adenovirus coexpressing CD/TK double suicide genes is mainly through cytotoxic effect and apoptosis.     

单纯疱疹病毒TK基因介导GCV治疗人RB肿瘤的实验研究

为探讨ＨＳＶ－ＴＫ基因介导的ＧＣＶ系统对人视网膜母细胞瘤（ＲＢ）基因治疗的有效性,利用电穿孔技术把重组逆转录病毒载体ｐＬＸＳＮ－ＴＫ导入包装细胞ＰＡ３１７,筛选出逆转录病毒产生细胞ＰＡ３１７／ＴＫ,收获病毒。体外实验：用逆转录病毒感染ＲＢ细胞,筛选出含ＴＫ基因的ＲＢ细胞（ＲＢ／ＴＫ）,用ＧＣＶ分别处理ＲＢ,ＲＢ／ＴＫ及不同比例的混合细胞。体内实验：建立人ＲＢ裸鼠原位异种移植模型,瘤内注射病毒液后再     

经膀胱灌注阳离子脂质体介导的HVS-TK基因对大鼠膀胱癌的杀伤作用

目的观察阳离子脂质体介导的HSV—TK基因经尿道膀胱灌注对大鼠膀胱肿瘤体内杀伤作用。方法N-甲基亚硝基脲(MNU)膀胱灌注诱导雌性Wistar大鼠膀胱肿瘤。经尿道HSV—TK基因膀胱灌注后，RT—PCR检测肿瘤组织中TK基因表达；TUNEL法检测肿瘤细胞凋亡；荷瘤膀胱总重量测定。结果HSV—TK基因经尿道膀胱灌注后．RT—PCR检测膀胱肿瘤组织有TK基因mRNA表达；TUNEL法凋亡检测，荷瘤膀胱总重量测定，提示治疗组与对照组差异有显著性。结论经尿道膀胱灌注阳离子脂质体-TK复合物可转导TK基因；联合GCV治疗，肿瘤生长被抑制；诱导肿瘤细胞凋亡可能是HSV—TK／GCV系统作用机理之一。     

Suicide gene therapy using adenovirus vector for human oral squamous carcinoma cell line in vitro

Recently, suicide gene therapy using the herpes simplex virus thymidine kinase (HSVtk) gene followed by ganciclovir (GCV) administration was evaluated for the treatment of cancer. The purpose of this study was to investigate the effectiveness of suicide gene therapy using the replication-deficient recombinant adenovirus vector for human oral squamous carcinoma cell lines. To evaluate transduction efficiency, each cell line was transduced in vitro with an adenovirus vector containing the beta-galactosidase gene. By 24 hours after transduction, nearly 100% of the cells were transduced at a multiplicity of infection (MOI) of 10, and from 30 to 10% at an MOI of 1. Next, each cell line was transduced with an adenovirus vector containing the HSVtk gene, and a subsequent administration of GCV for the assessment of suicide gene therapy. A subsequent administration of GCV resulted in complete tumor cell death. In addition, we conducted a morphological analysis of that cell death using video-enhanced contrast differential interference contrast microscopy, and we observed that it included both apoptosis and necrosis after HSVtk gene and GCV treatment. These results suggest that adenovirus-mediated suicide gene therapy induced remarkable cytotoxicity with a bystander effect in human oral squamous cell carcinoma thus suggesting an effective treatment strategy for that tumor.     

MDR1启动子调控的双自杀基因靶向杀伤耐药胶质瘤细胞的研究

目的探讨多药耐药基因（MDR1）启动子调控的CD、TK双自杀基因系统并加前体药物丙氧鸟苷及5 氟胞嘧啶（pcDNA3.MDR1P.CDTK/GCV+5-FC）对耐药胶质瘤细胞（C6/ADR细胞）的靶向杀伤作用。方法利用脂质体介导法将含有MDR1启动子调控的CD、TK双自杀基因的真核表达载体PcDNA3.MDR1P.CD.TK转染入C6/ADR细胞（C6/ADR/CDTK），利用PCR鉴定CD、TK基因的整合，利用RT-PCR鉴定CD、TK基因的表达；然后以转染了质粒pcDNA3.MDR1P.CDTK的C6细胞（C6/CDTK）和正常C6/ADR细胞作为对照，分别加前体药物，利用生长曲线、流式细胞仪、平板克隆形成等方法研究双自杀基因对耐药胶质瘤细胞生长、细胞周期及增殖的影响。结果PCR结果显示，CD、TK基因均整合入C6和C6/ADR细胞中；RT-PCR结果显示，C6/ADR/CDTK细胞中CD、TK基因有特异性表达，而C6/CDTK细胞无特异性表达。应用前体药物后，C6/ADR/CDTK细胞增殖明显受抑；C6/ADR、C6/CDTK、C6/ADR/CDTK细胞经流式细胞仪检测G1期的细胞比例分别为32.68%、47.57%、99.93%（P＜0.05，其平板克隆形成率分别为(96.7±2.1)%、(86.7±1.9)%、(16.7±0.9)%（P＜0.05）。结论pcDNA3.MDR1P.CDTK/GCV+5-FC系统对C6/ADR具有较强的靶向杀伤作用。     

Clinical Efficacy of Oral Ganciclovir for Prophylaxis and Treatment of Recurrent Herpes Simplex Keratitis

Background:Herpes simplex keratitis (HSK) caused by herpes simplex virus 1 (HSV-1),which has high recurrent rate and incidence of severe vision loss,is the leading cause of infectious blindness in the ...     

Anergic cells induced by the blockade of CD40-CD154 and CD28-B7 costimulatory pathways act as potent immunoregulatory cells in vitro and vivo

Background This study was to evaluate whether anergic cells induced by the blockade of CD40-CD154 and CD28-B7 costimulatory pathways can act as potent immunoregulatory cells in vitro and prolong cardiac allograft survival after adoptive transfer.Methods Anergic cells were induced in vitro by the addition of anti-CD154 and anti-CD80 monoclonal antibodies (mAbs) to primary MLR (mixed lymphocyte reaction) consisting of BALB/c as responder and C3H as stimulator. Anergic cells were added to a newly formed MLR in assessing the regulatory capacity and antigen specificity of anergic cells. The ability of anergic cells to respond to antigen and/or exogenous recombinant mouse interleukin-2 (rmIL-2) was tested. For in vivo studies, anergic cells were intravenously injected into 3.0-Gy γ-irradiated BALB/c mice immediately after heterotopic abdominal cardiac transplantation. To prolong allograft survival, recipient mice injected with anergic cells received rapamycin therapy ［1 mg·day（-1）·kg（-1）］.Results Anergic cells strongly suppressed the proliferation of naǐve BALB/c splenocytes against the original (C3H) stimulator in a dose-dependent manner, but they failed to suppress the proliferation of naǐve BALB/c splenocytes against the third-party （C57BL/6J） stimulator. The anergic state was reversed by both original (C3H) stimulator and additional exogenous IL-2. In in vivo studies, untreated irradiated BALB/c mice rejected C3H cardiac allografts with a mean survival time of (8.6±1.1) days, whereas those injected with the anergic cells rejected the allografts with a mean survival time of (11.8±1.9) days, which was slightly longer than that of the untreated mice. The protocol based on anergic cells injection plus rapamycin therapy could prolong allograft survival significantly ［(29.6±4.4) days］. Conclusions Anergic cells induced by the blockade of CD40-CD154 and CD28-B7 costimulatory pathways can act as potent immunoregulatory cells in vitro, and prolong cardiac allograft survival after adoptive transfer in the presence of rapamycin therapy. This procedure might be clinically useful for prolonging allograft survival if optimal protocols are developed.