野生型p53基因抑制膀胱癌细胞株HTB9生长及其机理的研究

目的：探讨野生型ｐ５３基因抑制膀胱癌生长的作用及其机理,方法：将野生型ｐ５３基是组腺病毒载体转染入膀胱癌细胞ＨＴＢ９,观察细胞生长曲线,细胞周期变化及ＤＮＡ合成情况,应用ＲＴ－ＰＣＲ检测ｐ２１ｍＲＮＡ水平,应用免疫组化法检测ｐ２１蛋白表达水平。结果：野生型ｐ５３基因导入可抑制ＨＴＢ９细胞生长和ＤＮＡ合成（ＡｄＣＭＶｐ５３）,流式细胞仪显示,ＤＮＡ合成前期或静止静的细胞比例增高,而合成期细胞比例下降,另外,ＡｄＣＭＶｐ５３还提高了ｐ２１的ｍＲＮＡ和蛋白水平,结论：腺病毒载体介导的野生型ｐ５３基因转梁对于膀胱可能是很有前途的基因治疗方法。     

腺病毒介导HSV-tk联合野生型p53 基因对直肠癌细胞的杀伤作用

应用自杀基因治疗肿瘤是一种有效的手段和方法 ,但ｐ53基因突变的肿瘤细胞可以对抗自杀基因转换前药对瘤细胞的杀伤作用。为克服突变ｐ53对自杀基因杀伤作用的影响 ,我们用腺病毒介导单纯疱疹病毒编码的胸苷激酶 (ＨＳＶ ｔｋ)基因和人野生型ｐ53基因共转染ＳＷ83 7直肠癌细胞 ,该细胞ｐ53基因第 2 4 8密码子发生了突变 ,观察ＨＳＶ ｔｋ/ＧＣＶ系统和ｐ53基因联合对肿瘤细胞的杀伤作用。将ＨＳＶ ｔｋ、人野生型ｐ53ｃＤＮＡ插入ｐＡｄＣＭＶ Ｌｉｎｋ1穿梭质粒多克隆位点 ,构建ｐＡｄＣＭＶ Ｌｉｎｋ1 (ｔｋ/ｐ53 ) ,ｐＡｄＣＭＶ Ｌｉｎ…     

重组腺病毒介导反义c-myc基因对人肝癌细胞系的治疗作用

目的：探讨重组腺病毒介导反义ｃ－ｍｙｃ基因（Ａｄ－ＡＳｍｙｃ）治疗人肝癌细胞的作用。方法：观察Ａｄ－ＡＳｍｙｃ对人肝癌细胞系的转导效率,通过细胞生长曲线、克隆形成实验、ＤＮＡ片段化分析、ＲＴ－ＰＣＲ、裸鼠皮下移植瘤治疗实验,分析Ａｄ－ＡＳｍｙｃ对人肝癌细胞系Ｂｅｌ－７４０２、ＱＳＧ－７７０１、ＳＭＭＣ－７７２１和ＨＣＣ－９２０４细胞生长和ｃ－ｍｙｃ基因表达及裸鼠肿瘤生长的抑制作用。结果：Ａｄ－ＡＳｍｙｃ可高效转导人肝癌细胞系,抑制细胞生长;转染细胞克隆形成能力降低,克隆成活率为对照组的５３．９％～６９．１％,ｃ－ｍｙｃ基因表达下降;Ａｄ－ＡＳｍｙｃ处理肝癌细胞,ＤＮＡ凝胶电泳出现明显的梯形条带,瘤内注射Ａｄ－ＡＳｍｙｃ可抑制裸鼠皮下移植瘤生长。结论：重组腺病毒介导的反义ｃ－ｍｙｃ基因转移,有可能成为肝癌基因治疗     

p53基因对鼻咽癌细胞株CNE－3裸鼠致瘤抑制作用的研究

分别将野生型和突变型ｐ５３基因导入鼻咽癌的体外培养细胞系ＣＮＥ－３．裸鼠致瘤试验表明，导入野生型ｐ５３基因的细胞系，肿瘤生长速度明显低于对照细胞系及导入突变型ｐ５３基因的细胞系；导入突变型ｐ５３基因的细胞系肿瘤生长速度最快；导入野生型ｐ５３基因的细胞系肿瘤生长速度最慢，而且肿瘤出现时间也较导入突变型ｐ５３的细胞及对照细胞晚１～２周。这说明野生型ｐ５３基因能有效地抑制肿瘤的生长，而实变型ｐ５３基因则可以促进肿瘤生长。这是首次有关ｐ５３基因对鼻咽癌细胞作用的报道。这一研究更进一步说明了ｐ５３基因的功能，对于鼻咽癌发生机理的探讨以及肿瘤的防治具有重要意义。     

重组腺病毒介导入野生型p53,GM-CSF和B7-1基因对肿瘤化疗耐药细胞生物学行为的影响

目的：探讨重组腺病毒分导入野生型ｐ５３,ＧＭ－ＣＳＦ和Ｂ７－１基因对肿瘤化疗耐药细胞生物学行为的影响,为临床使用该重组腺病毒治疗多药耐药的肿瘤提供实验基础。方法：选用ｐ５３异常的ＫＢ－ｓ（ＶＣＲ敏感）和ＫＢ－ｖ２００（ＶＣＲ耐药）细胞作为肿瘤化疗药物敏感和耐药的模式细胞,感染携带人野生型ｐ５３,ＧＭ－ＣＳＦ和Ｂ７－１基因的重组腺病毒后,观察这两种转基因癌细胞的生物学行为（包括药物敏感性）的变化。结果：药物敏感和耐药细胞都对腺病毒易感,重组腺病毒携带的三个外源基因（ｐ５３、ＧＭ－ＣＳＦ、Ｂ７－１基因）在两种细胞中都能得到有效表达,并且能抑制它们的生长及诱导其凋亡。耐药细胞 ＫＢ－ｖ２００在转染该重组腺病毒 ４８ｈ后,其细胞膜上 Ｐｇｐ糖蛋白的泵出药物的功能却受到显著影响,表现为罗丹明１２３在其细胞内的积累增加。ＭＴＦ的实验结果也显示出其对ＶＣＲ药物敏感性的增加,裸鼠体内实验证实了感染上述重组腺病毒的ＫＢ－ｖ２００细胞的致瘤性降低,同时能增加对化疗药物ＶＣＲ的敏感性。结论：实验研究结果提示,使用该重组腺病毒并结合化疗药物,对临床治疗多药耐药的肿瘤可能会更有效。     

Ａｄ-ＩＮＧ４抑制裸鼠人肝癌移植瘤生长的体内实验研究

目的　研究携带ＩＮＧ４基因的重组腺病毒（Ａｄ-ＩＮＧ４）对人肝癌细胞株ＳＭＭＣ-７７２１移植瘤生长的抑制作用及其潜在的分子机制。方法　将扩增的Ａｄ-ＩＮＧ４感染ＳＭＭＣ-７７２１细胞,Ｗｅｓｔｅｒｎｂｌｏｔ法检测Ａｄ-ＩＮＧ４在ＳＭＭＣ-７７２１细胞中的转录。用ＳＭＭＣ-７７２１细胞建立裸鼠人肝癌移植瘤模型,予Ａｄ-ＩＮＧ４（１×１０^９ｐｆｕ／ｍｌ）５０μｌ对移植瘤瘤体注射治疗,观察肿瘤生长变化;３周后处死裸鼠,摘除瘤体,称瘤重;免疫组化法检测ｐ２１、ＣＯＸ-２、Ｆａｓ、Ｂｃｌ-２、Ｂａx、Ｃａｓｐａｓｅ-３、ＶＥＧＦ、ＣＤ３４等因子的表达。结果　Ａｄ-ＩＮＧ４在ＳＭＭＣ-７７２１细胞中成功表达;Ａｄ-ＩＮＧ４对裸鼠人肝癌移植瘤有明显的生长抑制作用,Ａｄ-ＩＮＧ４组瘤体显著减小（Ｐ＜０.０１）,抑瘤率达４１.６４％;免疫组化检测显示,Ａｄ-ＩＮＧ４抑癌的分子机制可能与上调ｐ２１、Ｆａｓ、Ｂａｘ和Ｃａｓｐａｓｅ-３的表达及下调ＣＯＸ-２、Ｂｃｌ-２、ＶＥＧＦ和ＣＤ３４的表达有关。结论　Ａｄ-ＩＮＧ４能有效抑制ＳＭＭＣ-７７２１裸鼠人肝癌移植瘤的生长,其机制可能通过抑制肿瘤细胞生长、血管形成和激活细胞凋亡等多个途径共同发挥抑癌效应。     

Ad—p53与Ad—p16联合对人肺腺癌GLC—82细胞作用的研究

目的：探讨腺病毒介导的ｐ５３与ｐ１６基因联合对人肺腺癌ＧＬＣ－８２疗效提高的可能性。方法：将分别携有ｐ５３基因、ｐ１６基因重组腺病毒（Ａｄ－ｐ５３与 Ａｄ－ｐ１６）联合使用,通过细胞生长和存活实验、克隆形成实验、流式细胞分析、ＴＵＮＥＬ检测、ＲＴ－ＰＣＲ分析、免疫组织化学实验,观察其对人肺腺癌ＧＬＣ－８２细胞的作用。结果：在总感染强度相同的前提下,Ａｄ－ｐ５３与Ａｄ－ｐ１６联合导入ＧＬＣ－８２细胞,对细胞生长存活及克隆形成能力的抑制、以及所造成的凋亡效果比施用单种基因的效果强,表明ｐ５３基因与ｐ１６基因在体外疗效上互为协同。结论：Ａｄ－ｐ５３与Ａｄ－ｐ１６联合,可以提高对人肺腺癌ＧＬＣ－８２细胞的疗效。     

腺病毒介导野生型p53基因对人白血病细胞系HL-60、K_(562)生长的抑制作用

目的探索肿瘤抑制基因ｐ５３对人白血病细胞系的生长抑制作用和促凋亡作用。方法选用含野生型ｐ５３基因的重组腺病毒载体,体外感染人白血病细胞系ＨＬ－６０、Ｋ５６２。通过细胞生长曲线,ＤＮＡ检测及流式细胞仪分析检测转染细胞的增殖受抑制和细胞凋亡的发生。结果ＰＣＲ检测转染后ＨＬ－６０和Ｋ５６２细胞ｐ５３ｃＤＮＡ表达。转染后Ａｄ／ｐ５３病毒对ＨＬ－６０细胞和Ｋ５６２细胞的生长有抑制作用。随着Ａｄ／ｐ５３病毒浓度加大,ＨＬ－６０和Ｋ５６２细胞的ＯＤ值越低即生长抑制程度越大。经Ａｄ／ｐ５３病毒转染的ＨＬ－６０和Ｋ５６２细胞均有明显的细胞凋亡峰出现,对照细胞则无。细胞周期分析无明显异常发现。结论重组腺病毒载体介导的野生型ｐ５３基因在体外对人白血病细胞系ＨＬ－６０和Ｋ５６２的生长有抑制作用,能导致细胞凋亡的发生。     

野生型p53基因的导入对膀胱癌细胞抑制作用的观察

转染外源野生型ｐ５３基因对膀胱癌ＥＪ细胞的抑制作用。方法将含外源野生型ｐ５３基因的（ａｄ┐Ｗｔｐ５３）转染膀胱癌ＥＪ细胞,观察生长曲线,细胞周期变化及裸鼠体内抑瘤试验。结果转染了ａｄ┐Ｗｔｐ５３的ＥＪ细胞在体外生长速率下降,在裸鼠体内致瘤性丧失,流式细胞仪显示,ＤＮＡ合成前期或静止期的细胞比例增高。另外,ａｄ┐Ｗｔｐ５３直接注射到肿瘤组织内,可使外源野生型ｐ５３基因在肿瘤细胞内有效、稳定的表达,肿瘤表现为生长减缓,最后停止生长并有缩小。结论腺病毒载体介导基因转染效率高,速度快,安全,是很有前途的体内基因治疗载体。     

p53反义RNA对肠癌细胞恶性表型的抑制作用

研究ｐ５３反义ＲＮＡ对大肠癌细胞中突变型ｐ５３致癌性的抑制效应,为肿瘤基因治疗提供新思路。方法２．１ｋｂ的人ｐ５３全长ｃＤＮＡ反向插入哺乳动物表达载体ｐＲＥＰ９,得到ｐ５３反义ＲＮＡ表达载体ｐＲＥＰ９－ｐ５３（ＡＳ）,并将其导入人肠癌细胞株ＳＷ１１１６（内源性突变型ｐ５３）,采用ＭＴＴ和ＦＣＭ方法测定ｐＲＥＰ９－ｐ５３（ＡＳ）表达的ｐ５３反义ＲＮＡ对ＳＷ１１１６细胞生长的影响。结果带有ｐＲＥＰ９－ｐ５３（ＡＳ）的ＳＷ１１１６细胞,与对照组ＳＷ１１１６细胞和带ｐＲＥＰ９空载体的ＳＷ１１１６细胞相比,由于ｐ５３反义ＲＮＡ的表达,其增殖速度显著下降,ＦＣＭ的结果也证明带ｐＲＥＰ９－ｐ５３（ＡＳ）的细胞部分受阻于Ｇ０／１期,而带ｐＲＥＰ９空载体的细胞则无明显变化。结论ｐ５３反义ＲＮＡ可以有效地抑制大肠癌细胞中突变型ｐ５３的致癌性,可用于实验性肿瘤基因治疗研究     

Growth inhibition of human laryngeal cancer cell with the adenovirus-mediated p53 gene

Mostmalignanciesarediseasegeneratedwithaprocessofgeneticalteration.Basedonthistheory,newapproachestocancertherapyarebeingdevel0ped.Oneoftheseisgenetherapy.Amongthegeneshavingtherapeuticpotentialforcancertreatment,thep53tumorsuppressorgenehasbeenmostextensivelystudied.[l]Wild-typep53hasbeenshownt0beinvolvedintranscirptionalregulation.ItarrestscellsattheGllScheckpoint,blocksDNAreplicati0nandinducesap0ptosis."'Recentstudieshavesh0wnthatwild-typep53genecansuppressthegrowthofsomehumancancercelll…     

Therapeutic efficacy of adenoviral-mediated p53 gene transfer is synergistically enhanced by combined use of antisense oligodeoxynucleotide targeting clusterin gene in a human bladder cancer model

To establish a more effective therapeutic strategy against advanced bladder cancer, we investigated the effects of combined treatment with antisense (AS) oligodeoxynucleotide (ODN) targeting the anti-apoptotic gene clusterin and adenoviral-mediated p53 gene transfer (Ad5CMV-p53) using the human bladder cancer KoTCC-1 model. Clusterin expression in KoTCC-1 cells was highly upregulated by Ad5CMV-p53 treatment; however, AS clusterin ODN treatment further suppressed clusterin expression in KoTCC-1 cells after Ad5CMV-p53 treatment. AS clusterin ODN treatment synergistically enhanced the cytotoxic effect of Ad5CMV-p53, and DNA fragmentation characteristic of apoptosis was observed only after combined treatment with AS clusterin ODN and Ad5CMV-p53, but not after treatment with either agent alone. Administration of AS clusterin ODN and Ad5CMV-p53 into nude mice resulted in a significant inhibition of KoTCC-1 tumor growth as well as lymph node metastases compared to administration of either agent alone. Furthermore, combined treatment with AS clusterin ODN, Ad5CMV-p53, and cisplatin completely eradicated KoTCC-1 tumors and lymph node metastases in 60% and 100% of mice, respectively. These findings suggest that combined treatment with AS clusterin ODN and Ad5CMV-p53 could be a novel strategy to inhibit bladder cancer progression, and that further additional use of a chemotherapeutic agent may substantially enhance the efficacy of this combined regimen.     

Inhibitory effects of 5-Aza-2′-deoxycytidine and trichostatin A in combination with p53-expressing adenovirus on human laryngocarcinoma cells

Objective: To investigate the effects of 5-Aza-2’-deoxycytidine (5-Aza-Cdr) and trichostatin A (TSA) combined with p53-expressing adenovirus (Ad-p53) on Hep-2 cell line in vivo and in vitro, in order to explore its possibility in biological treatment of laryngocarcinoma. Methods: Effects of 5-Aza-Cdr and TSA in combination with Ad-p53 on Hep-2 cell line in vivo were determined by Cell Counting Kit-8 (CCK-8) assay. The effect of drug combination was calculated by Jin’s formula. Effects on the cell line in vitro were investigated by establishing the nude mice model. Results: 5-Aza-Cdr and TSA showed inhibitory effects on the proliferation of Hep-2 cells in dose- and time-dependent manner. Ad-p53 can inhibit the growth of Hep-2 cells in vivo and in vitro. However, the combination of epigenetic reagents (5-Aza-Cdr/TSA) and Ad-p53 was less effective than individual use of Ad-p53. 5-Aza-Cdr and Ad-p53 inhibited the growth of transplanted tumors and reduced the volume of tumors, and the tumor volume of Ad-p53 group was significantly smaller than that of the control group (P<0.05). Conclusion: Both epigenetic reagents (5-Aza-Cdr/TSA) and Ad-p53 can suppress cell proliferation on Hep-2 in vivo and in vitro and there may be some antagonistic mechanism between Ad-p53 and epigenetic reagents (5-Aza-Cdr/ TSA).     

Adenoviral p53 gene therapy promotes heat-induced apoptosis in a nasopharyngeal carcinoma cell line.

BACKGROUND: It has previously been demonstrated that Ad5CMV-p53 gene transfer, either used alone or delivered concomitantly with ionizing radiation, resulted in cytotoxicity mediated by apoptosis in nasopharyngeal carcinoma (NPC) cell lines. In this study, a novel approach was evaluated of combining Ad5CMV-p53 gene therapy with hyperthermia (HT), in the CNE-1 NPC cell line, which harbours a mutation in codon 249 of the p53 gene. MATERIALS AND METHODS: CNE-1 cells were infected using either Ad5CMV-p53 or Ad5CMV-B-gal, followed, 24 h later, by HT (43 degrees C x 0-2 h). Protein was extracted for Western blot analysis, and apoptosis was evaluated using acridine-orange ethidium bromide staining, followed immediately by fluorescent microscopy examination for the proportion of cells displaying morphologic features of apoptosis. RESULTS: Ad5CMV-p53 gene therapy combined with HT resulted in a dose-dependent cytotoxicity with less than 1% clonogenic survival when 10 pfu/cell of Ad5CMV-p53 was combined with 2 h heating at 43 degrees C. Western blotting demonstrated that treatment with Ad5CMV-p53 resulted in the rapid expression of p53, which was minimally affected by HT. The inducible form of hsp70 was maximally expressed at 48 h post-HT, with minimal effect when cells were additionally treated with Ad5CMV-p53. Clonogenic cytotoxicity was associated with the development of apoptosis, with up to 70% of CNE-1 cells displaying morphologic features of apoptosis after the combination treatments. CONCLUSION: Based on the shapes of the clonogenic survival curves, Ad5CMV-p53 gene therapy and HT appear to interact in an additive manner, suggesting the therapeutic potential of this combined treatment approach for patients with NPC.     

Cisplatin chemotherapy plus adenoviral p53 gene therapy in EBV-positive and -negative nasopharyngeal carcinoma

We have previously shown that the introduction of human recombinant wild-type p53 mediated by an adenoviral vector (Ad5CMV-p53), either alone or delivered in combination with ionizing radiation, was cytotoxic to two nasopharyngeal carcinoma (NPC) cell lines. To further explore the potential therapeutic role for gene therapy, the combination of Ad5CMV-p53 and cisplatin was examined in two NPC cell lines, CNE-1 and C666-1. The C666-1 cells are particularly relevant because they express Epstein-Barr virus latent gene products analogous to human NPC in situ. Cells were infected with 5 pfu/cell of Ad5CMV-p53 or Ad5CMV-beta-gal, followed by exposure to increasing doses of cisplatin. Clonogenic and MTT assays were used to assess the sensitivity of cells to these treatments, and apoptosis was also quantified. The combination of Ad5CMV-p53 and cisplatin resulted in approximately 25% greater cytotoxicity compared to that observed with cisplatin alone in either cell line. Apoptosis was induced in approximately 50% of cells following administration of both Ad5CMV-p53 and cisplatin, but was induced in considerably fewer cells following either treatment alone. The two modalities appeared to interact in an additive manner. Ad5CMV-p53 gene therapy resulted in the expression of biologically active p53 protein, shown by induction of p21(WAF1/CIP1). Cisplatin treatment showed little effect on either p53 or p21(WAF1/CIP1) expression. Therefore, both p53 gene therapy and cisplatin chemotherapy demonstrated cytotoxicity mediated by apoptosis despite the presence of EBV gene products in the C666-1 cells, but it appears that the two modalities induce cytotoxicity by independent pathways.     

转染 p53基因对肺腺癌细胞株裸鼠 移植瘤生长的影响

目的：探讨转染野生型 p53（ wt-p53）和突变型 p53（ mt-p53）基因对人肺腺癌细胞株 GLC-82裸鼠移植瘤生长的影响。方法：采用脂质体介导法,分别将 wt-p53和 mt-p53基因导入人肺腺癌细胞株 GLC-82,在裸鼠体内、体外实验中检测转导细胞的生长状况和裸鼠致瘤性。结果：转染 mt-p53 基因的细胞株 G418筛选的细胞集落数、 3H-TDR掺入实验、软琼脂平皿细胞集落数,以及裸鼠瘤组织重量和体积均高于对照组（ P<0.01）,而转染 wt p53基因的细胞株均显著低于对照组（ P< 0.01）,表明导入 wt p53基因的细胞株瘤细胞生长速度明显低于对照组细胞株和导入 mt p53基因的细胞株,即导入 mt p53基因的细胞株瘤细胞生长速度最快,而导入 wt p53基因的细胞株瘤细胞生长速度最慢。结论： wt p53基因能有效抑制人肺腺癌细胞生长; mt p53基因则可以明显地促进瘤细胞生长。     

The effects of combining ionizing radiation and adenoviral p53 therapy in nasopharyngeal carcinoma

PURPOSE: Nasopharyngeal carcinoma (NPC) is a malignant disease of the head/neck region, with a 5-year survival level of approximately 65%. To explore gene therapy as a novel approach which might improve outcome, we have shown previously that introduction of human recombinant wild-type p53 mediated by the adenoviral vector (Ad5CMV-p53) was cytotoxic in two human nasopharyngeal carcinoma (NPC) cell lines (CNE-1 and CNE-2Z). The current work was designed to determine whether this strategy, combined with ionizing radiation (XRT), was more effective than either treatment alone. METHODS AND MATERIALS: CNE-1, CNE-2Z, and a normal human nasopharyngeal fibroblast strain, KS1, were infected with 2- and 6-plaque-forming units (pfu)/cell of Ad5CMV-p53, respectively. These doses were isoeffective for beta-galactosidase activity in the CNE-1 and CNE-2Z cells. XRT was administered 24 h post-infection, and Western blot analyses were conducted for p53, p21WAF1/CIP1, bax, and bcl-2 2 days after XRT. Cell survival was assessed using a clonogenic assay. Presence of DNA ladders reflecting apoptosis was detected using DNA agarose gel electrophoresis, and cell cycle was analyzed using flow cytometry. RESULTS: The combination of Ad5CMV-p53 plus XRT (2, 4, and 6 Gy) resulted in an approximately 1-log greater level of cytotoxicity compared to that observed with XRT alone for both NPC cell lines. The two modalities appear to be interacting in a synergistic manner in cancer cells, but not in KS1 fibroblasts. XRT alone stimulated minimal p53 expression in control cells; Ad5CMV-p53 alone induced significant recombinant p53 expression, which was not further enhanced by the addition of XRT. Similar observations were made for p21WAF1/CIP1 expression. No changes were observed for bax or bcl-2 expression with any of these treatments. Apoptosis was induced following 4 Gy of XRT alone, but was observed after only 2 Gy when combined with Ad5CMV-p53. Cell cycle analysis indicated that Ad5CMV-p53 infection did not perturb the cell cycle beyond that observed with XRT alone. CONCLUSION: p53 gene therapy and XRT appears to interact in a synergistic manner; underscoring the significant potential of this novel strategy in the treatment of NPC.     

Growth suppression and immunogenicity enhancement of Hep-2 or primary laryngeal cancer cells by adenovirus-mediated co-transfer of human wild-type p53, granulocyte-macrophage colony-stimulating factor and B7-1 genes

Co-transfer of immunomodulatory and antiproliferative genes may be the basis for new strategies to potentiate tumor regression. In this study, we evaluated the in vitro effect of the introduction of human wild-type p53, granulocyte-macrophage colony-stimulating factor (GM-CSF), and B7-1 genes via recombinant adenovirus on the growth and immunogenicity of Hep-2 or primary laryngeal cancer cells. By the introduction of wild-type p53 gene, the growth of Hep-2 cells was inhibited via enhanced apoptosis. By the introduction of GM-CSF and B7-1 genes, the immunogenicity of cancer cells was enhanced. Significant proliferation of tumor infiltrating lymphocytes (TILs) and tumor-specific cytotoxicity of cytotoxic T lymphocytes (CTLs) were induced in vitro. Furthermore, the combinative effect of GM-CSF and B7-1 was even more evident than that of any one of them singly. These results suggest that the co-transfer of human wild-type p53, GM-CSF and B7-1 genes into tumor cells via recombinant adenovirus may be further developed into a potential combination gene therapy strategy for cancer.     

RNA干扰hTERT基因治疗喉鳞状细胞癌的实验研究

目的:探讨RNA干扰hTERT(人端粒酶逆转录酶)基因对人喉鳞状细胞癌的治疗作用.方法:根据hTERT cDNA序列构建表达hTERT mRNA特异的、含荧光素基因的shRNA真核表达质粒pshRNA1、pshRNA2.将shRNA质粒分别转染人喉癌Hep-2细胞株及荷瘤裸鼠瘤体内.以激光共聚焦显微镜观察质粒在Hep-2细胞及瘤体内的表达;以MTT法观察质粒对Hep-2细胞增殖的抑制作用;以蛋白印迹法(Western blot法)检测Hep-2细胞中hTERT蛋白的表达;以免疫组化SP法检测裸鼠瘤体内hTERT蛋白的表达.结果:pshRNA1、pshRNA2转染Hep-2细胞及pshRNA1转染瘤体后,共聚焦显微镜下见大量的癌细胞表达绿色荧光,hTERT蛋白表达明显下降.细胞受pshRNA1、pshRNA2转染后,其生长活性受到明显抑制.体内抑瘤实验表明,与空质粒载体组(pshRNA4)和生理盐水组相比,pshRNA1组移植瘤生长明显受到抑制.结论:表达shRNA的、hTERT基因特异的真核表达质粒能有效转染体内、外喉鳞癌细胞,并可有效抑制人喉鳞癌细胞的生长,为今后应用RNA干扰基因治疗喉癌提供重要的实验参考.