E1B55kDa缺失的增殖腺病毒抗肿瘤效果差异及其分子机制

目的:观察E1B55kDa缺失的增殖腺病毒CNHK200和CNHK200-hA对A549肺癌和MBD-231乳腺癌动物模型的抗肿瘤效果,结合研究肿瘤细胞柯萨奇病毒-腺病毒受体(CAR)的表达状态,分析腺病毒抗肿瘤效果的差别及其分子机制。方法:建立A549肺癌和MBD-231乳腺癌裸鼠模型,给予病毒总剂量1×109pfu的CNHK200和CNHK200-hA治疗。观察期结束,取肿瘤标本进行柯萨奇病毒-腺病毒受体(CAR)和腺病毒壳蛋白Hexon的免疫组化定位。结果:在CAR水平高表达的A549细胞内,CNHK200-hA和CNHK200均可以有效增殖并杀伤肿瘤细胞,产生明显的疗效。相反,在CAR水平低下的MBD-231细胞内,CNHK200-hA和CNHK200没有增殖复制能力,CNHK200几乎没有任何治疗效果,CNHK200-hA的治疗效果仅由Angiostatin基因表达所产生。结论:CAR在E1B55kDa缺失的增殖腺病毒的感染和增殖过程中起着至关重要的作用,肿瘤细胞CAR表达低下可以影响腺病毒载体的感染力和增殖力,从而降低用腺病毒进行肿瘤基因治疗的疗效。     

E1B55kDa缺陷型腺病毒对人肝癌细胞的杀伤研究

目的 探讨E1B55kDa缺陷型腺病毒dl1520对肝癌细胞的体内外杀伤作用。方法 用dl1520分别感染p53基因型不同的人肝癌细胞,感染后第4天用染色的方法检测存活细胞。用RT－PCR检测细胞内p53和p21^Waf-1基因表达的改变,通过检测腺病毒衣壳蛋白hexon基因的表达证实腺病毒的感染。在SCID裸鼠瘤体内注射dl1520,观察dl1520对肝癌细胞的体内杀伤作用。结果 p53基因缺失的肝癌细胞Hep3B对dl1520诱导的细胞毒性作用最敏感,超过60％的细菌被杀伤,而不足20％的PLC／PRF／5（p53基因突变型）和HepG2(p53基因野生型）肝癌细胞被杀伤。腺病毒感染后,HepG2细胞内p53和p21^Waf-1基因表达水平均明显升高。瘤体内注射dl1520,可显著抑制Hep3B裸鼠移植瘤的生长,而对PLC／PRF／5和HepG2的裸鼠移植瘤则无明显的生长抑制作用。结论 E1B55kDa缺失的腺病毒可以选择性地杀伤p53基因缺失的肝癌细胞,是一种潜在的肿瘤治疗手段。     

A novel Golgi protein (GOLPH2)-regulated oncolytic adenovirus exhibits potent antitumor efficacy in hepatocellular carcinoma

Golgi apparatus is the organelle mainly functioning as protein processing and secretion. GOLPH2 is a resident Golgi glycoprotein, usually called GP73. Recent data displayed that GOLPH2 is a superb hepatocellular carcinoma (HCC) marker candidate, and even its specificity is better than liver cancer marker AFP. Oncolytic adenoviruses are broadly used for targeting cancer therapy due to their selective tumor-killing effect. However, it was reported that traditionally oncolytic adenovirus lack the HCC specificity. In this study, a novel dual-regulated oncolytic adenovirus GD55 targeting HCC was first constructed based on our cancer targeted gene-viral therapeutic strategy. To verify the targeting and effectiveness of GOLPH2-regulated oncolytic adenovirus GD55 in HCC, the anticancer capacity was investigated in HCC cell lines and animal model. The results proved that the novel GOLPH2-regulated GD55 conferred higher adenovirus replication and infectivity for liver cancer cells than oncolytic adenovirus ZD55. The GOLPH2-regulated GD55 exerted a significant grow-suppressing effect on HCC cells in vitro but little damage to normal liver cells. In animal experiment, antitumor effect of GD55 was more effective in HCC xenograft of nude mice than that of ZD55. Thus GOLPH2-regulated GD55 may be a promising oncolytic virus agent for future liver cancer treatment.     

包载TIMP-1重组腺病毒微球的制备及其对肝癌细胞增殖的抑制

目的：制备携带人基质金属蛋白酶组织抑制因子1（tissue inhibitors of metalloproteinase1,TIMP1）的重组腺病毒乳酸聚乙烯醇（polyDLlactidepoly,PELA）微球,探讨其对HepG2肝癌细胞增殖的影响。方法：采用溶剂挥发法双乳液体系,以可降解的生物材料PELA包被携带TIMP1基因的重组腺病毒制成微球,测定其粒径、载病毒量、包封率及释放规律。重组腺病毒微球感染HepG2细胞,荧光显微镜观测感染效率,透射电镜观测超微结构,半定量RTPCR检测TIMP1 mRNA表达;MTT法检测HepG2细胞增殖。结果：成功构建包载TIMP1重组腺病毒的PELA微球,直径约1.965 μm,包封率为60%,载病毒率为10.5×108efu/mg,在120 h内释放病毒量接近60%,总的释放时间长于240 h。空白微球无毒性PELA病毒微球感染HepG2细胞后,细胞稳定表达TIMP1 mRNA;对HepG2细胞的增殖有明显抑制作用,抑制率表达47%。结论：包载TIMP1重组腺病毒的PELA微球可抑制肝癌HepG2细胞的增殖,为化学高分子载体运载基因治疗肝癌提供了实验依据。     

Inhibitory effect of recombinant adenovirus carrying melittin gene on hepatocellular carcinoma.

OBJECTIVES: To search for a new clinical application of melittin (Mel): treating hepatocellular carcinoma with Mel gene. METHODS: Recombinant adenoviruses carrying the Mel gene and alpha-fetoprotein (AFP) promoter (Ad-rAFP-Mel) were constructed through a bacterial homologous recombinant system. The efficiency of adenovirus-mediated gene transfer and the inhibitory effect of Ad-rAFP-Mel on the proliferation of hepatocarcinoma cells were determined by X-gal stain and MTT assay, respectively. The tumorigenicity of hepatocarcinoma cells transfected by Ad-rAFP-Mel and the antitumor effect of Ad-rAFP-Mel on transplanted tumor in nude mice were detected in vivo. RESULTS: The Mel mRNA was transcribed in BEL-7402 hepatocellular carcinoma cells transducted by Ad-rAFP-Mel. The efficiency of adenovirus-mediated gene transferred to BEL-7402 cells was 100% when the multiplicity of infection of Ad-rAFP-Mel was 10 in vitro, and was also high in vivo. The inhibitive rates of Ad-rAFP-Mel and Ad-rAFP for BEL7402 cells were 66.2 +/- 2.7% and 2.9 +/- 2.3% (t=30.83, P=6.6 x 10(-6)) by MTT assay. The inhibitive rates of Ad-CMV-Mel for BEL7402, SMMC7721 and L02 cells were 58.9 +/- 9.6%, 65.9 +/- 3.8% and 31.7 +/- 1.2%, respectively, and of Ad-rAFP-Mel were 66.2 +/- 2.7%, 16.1 +/- 6.6% and 7.5 +/- 3.3%, respectively (t=1.27, P=0.27; t=11.31, P=3.5 x 10(-4); and t=12.12, P=2.7 x 10(-4) versus the Ad-CMV-Mel group in the same cells). The tumorigenicity rates of hepatocarcinoma cells transfected by Ad-rAFP-Mel were decreased. A significant antineoplastic effect was detected on transplanted tumor in nude mice by intratumoral injection of Ad-rAFP-Mel. CONCLUSIONS: Ad-rAFP-Mel can inhibit specifically proliferation of AFP-producing human hepatocarcinoma cells in vitro and in vivo. This suggests that animal toxin gene can be used as an antitumor gene.     

Enhanced antitumor efficacy of a novel fiber chimeric oncolytic adenovirus expressing p53 on hepatocellular carcinoma

Oncolytic adenoviruses may offer a new treatment option and improve the prognosis for patients with hepatocellular carcinoma (HCC). However, the antitumor efficacy of oncolytic adenoviruses on HCC cells is compromised due to low expression of the adenovirus serotype 5 (Ad5) receptor on the target cells. In this study we showed that all HCC cell lines and clinical samples expressed high level of CD46, the receptor for Adenovirus 35 (Ad35) and constructed new fiber chimeric oncolytic adenoviruses with or without a p53 gene expression cassette, SG635-p53 and SG635, respectively. These variants were derived from the previously described Ad5 vectors SG600-p53 and SG600 by replacing the Ad5 fiber with a chimeric Ad5/35 fiber. It was found that the 5/35 fiber chimeric adenovirus vector (Ad5/35-EGFP) demonstrated significantly improved transduction in all tested HCC cell lines compared with the Ad5 vector (Ad5-EGFP). The new fiber chimeric oncolytic adenoviruses produced more progeny viruses in HCC cells than did the Ad5-based viruses but replicated weakly in normal fibroblast BJ cells. In addition, SG635-p53 mediated a higher level of transgenic expression than SG600-p53 in Hep3B and Huh7 cells and showed a markedly enhanced antitumor effect on HCC cells in vitro compared with SG635 or SG600-p53 without causing significant cytotoxicity to normal cells. Antitumor activity of SG635-p53 was shown in Hep3B subcutaneous xenograft tumor models following intratumoral injection, resulting in significant inhibition of tumor growth and prolonged survival of animals. Our data suggest that SG635-p53, as a fiber chimeric oncolytic adenovirus in combination with p53 expression, may serve as a novel, promising and safe anticancer agent for the treatment of HCC.     

腺病毒E1a基因增强P16基因诱导SMMC-7721肝癌细胞的凋亡

目的:研究腺病毒E1a基因与P16抑癌基因协同对肝癌SMMC-7721细胞凋亡和增殖的影响,探索肿瘤基因治疗新模式.方法:构建E1a基因真核表达质粒pDC315-E1a和携带P16的重组病毒AdCMV-P16,RT-PCR和免疫荧光标记法检测pDC315-E1a质粒转染或AdCMV-P16病毒感染后SMMC-7721细...     

复制缺陷型腺病毒Ad-p14ARF治疗肝细胞癌的实验研究及作用机制的探讨

Objective： To study the therapeutic effect and mechanisms of recombinant adenovirus Ad-p14ARF in hepatocellular carcinoma cell lines. Methods： Morphology and trypan blue assay were adopted to evaluate the proliferation of different liver cancer cells after Ad-p14ARF infection. Cell apoptosis was confirmed by detecting phosphatidylserine （PS） externalization with Annexin V/PI double staining. Western blotting assay analyzed the expression of related proteins. Subcutaneous tumor model of BEL7402 was established to evaluate the therapeutic ability of Ad-p14ARF. Results： Ad-p14ARF suppressed cell growth, proliferation and promoted cell apoptosis of cancer cell lines with different genetic background. Ad-p14ARF inhibited growth of liver cancer cells （HepG2, BEL7402） in a dose-dependent manner. Ad-p14ARF leaded to overexpression of Bax and p21, which were the downstream regulating genes of p53. Ad-p14ARF suppressed tumor growth significantly in the experimental therapy in nude mice bearing subcutaneous tumor of BEL7402. Conclusion： P14ARF gene is a powerful tumor suppressor gene to be used in cancer gene therapy. It may play an important role in gene therapy against the malignancies in the future.     

树突状细胞和基因缺陷腺病毒联合治疗小鼠前胃癌的实验研究

目的观察树突状细胞(den-driticcells,DCs)和基因缺陷腺病毒联合治疗小鼠前胃癌的疗效。方法建立小鼠前胃癌动物模型,在体外分化、诱导DCs;瘤内注射基因缺陷腺病毒,观察肿瘤坏死情况;再在瘤体内注射DCs,观察给药侧瘤体及对侧瘤体体积、小鼠生存情况和特异性细胞毒T淋巴细胞(cytotoxicT-lymphocyte,CTL)活性。结果肿瘤组织局部应用基因缺陷腺病毒后,产生明显坏死;瘤内应用DCs,对侧瘤体体积明显缩小,P=0·000;小鼠的生存率提高,且能产生特异性CTLs,能特异性杀伤小鼠前胃癌细胞,P<0·01。结论DCs和基因缺陷腺病毒联合治疗可抑制小鼠前胃癌生长,诱导机体特异性抗肿瘤免疫反应,二者联合应用,可产生协同效应并加强其抗肿瘤效果。     

Cyclophosphamide enhances antitumor efficacy of oncolytic adenovirus expressing uracil phosphoribosyltransferase (UPRT) in immunocompetent Syrian hamsters

Oncolytic viruses (OVs) are novel cancer therapeutics with great promise, but host antiviral immunity represents the hurdle for their efficacy. Immunosuppression by cyclophosphamide (CP) has thus been shown to enhance the oncolytic efficacy of many OVs, but its effects on OVs armed with therapeutic genes remain unknown. We have previously reported on the efficacy of AxE1CAUP, an oncolytic adenovirus (OAd) expressing uracil phosphoribosyltransferase (UPRT), an enzyme that markedly enhanced the toxicity of 5‐fluorouracil (5‐FU), in immunodeficient, Ad‐nonpermissive nude mice. Here we explored the efficacy and safety of intratumoral (i.t.) AxE1CAUP/5‐FU therapy and of its combination with CP for syngenic HaP‐T1 pancreatic cancers in immunocompetent, Ad‐permissive Syrian hamsters. AxE1CAUP infected, replicated, expressed UPRT, and increased the sensitivity to 5‐FU in HaP‐T1 cells in vitro. I.t. AxE1CAUP/5‐FU treatment inhibited the growth of subcutaneous HaP‐T1 allografts. The combination with high‐dose CP inhibited serum Ad‐neutralizing antibody formation, increased intratumoral AxE1CAUP replication and UPRT expression, and resulted in further enhanced therapeutic effects with 5‐FU. Neither body weight nor histology of the liver and lung changed during these treatments. A clinically‐approved, intermediate‐dose CP also enhanced the efficacy of i.t. AxE1CAUP/5‐FU treatment in these hamsters, which was not affected by preexisting immunity to the vector. These data demonstrate the excellent antitumor efficacy and safety of an OAd armed with a suicide gene in combination with CP for treating syngenic tumors in immunocompetent, Ad‐permissive animals, indicating the efficacy of CP in overcoming the hurdle of antiviral immunity for effective OV‐mediated gene therapy.     

Survivin promoter-regulated oncolytic adenovirus with Hsp70 gene exerts effective antitumor efficacy in gastric cancer immunotherapy

Gene therapy is a promising adjuvant therapeutic strategy for cancer treatment. To overcome the limitations of current gene therapy, such as poor transfection efficiency of vectors, low levels of transgene expression and lack of tumor targeting, the Survivin promoter was used to regulate the selective replication of oncolytic adenovirus in tumor cells, and the heat shock protein 70 (Hsp70) gene was loaded as the anticancer transgene to generate an AdSurp-Hsp70 viral therapy system. The efficacy of this targeted immunotherapy was examined in gastric cancer. The experiments showed that the oncolytic adenovirus can selectively replicate in and lyse the Survivin-positive gastric cancer cells, without significant toxicity to normal cells. AdSurp-Hsp70 reduced viability of cancer cells and inhibited tumor growth of gastric cancer xenografts in immuno-deficient and immuno-reconstruction mouse models. AdSurp-Hsp70 produced dual antitumor effects due to viral replication and high Hsp70 expression. This therapeutic system used the Survivin promoter-regulated oncolytic adenovirus vector to mediate targeted expression of the Hsp70 gene and ensure safety and efficacy for subsequent gene therapy programs against a variety of cancers.     

Reversal of Adriamycin Resistance of Hepatocellular Carcinoma by Targeting with Recombined Adenovirus Carring Antisense mdr1 RNA

OBJECTIVE Chemotherapy is an important therapy for hepatocellular carcinoma （HCC）. However, it is not effective in many cases due to recurrence and metastasis even if the initial treatment produces a response. Multidrug resistance （MDR） is considered to be one of the considerable causes. The aim of this study was to reverse MDR of HepG2/ADM cells by blocking mdr1 with an adenovirus vector carrying antisense mdr1 in a tumor transplantated in athymic mice. METHODS PCMV IE was removed from the pshuttle vector. A 0.3 kb AFP promoter was inserted into the pshuttle vector and pCMV changed into pAFP. The pAFP and asmdr1 PCR products were doubly digested with Kpnl and Apal, the digested products were ligated by T4 ligase, the asmdr1 gene was inserted into pAFP and a newly plasmid pAFP-asmdr1 was constructed. Following digestion with PI-SceI/I-Ceu I, pAFP-asmdr1 was ligated with Adeno-X genome DNA and amplified in E.coli XL1-Blue. The HEK293 cells were transfected and virus collected. The HepG2 MDR cells （HepG2/ADM） were induced by graded resistance to ADM and were inoculated into athymic mice. After adeno-asmdr1 was injected, the expression of mdr1-mRNA and the volume of the transplantated tumor and its cells were observed. RESULTS Following injection with Adeno-asmdr1, the tumor volume in the ADM＋Adeno-asmdr1 group did not increase. However the tumor volume in the PBS plus ADM group did significantly increase （P〈0.05）. In the tumor xenograft cells, mdr1 mRNA in the xenografts was assessed by RT-PCR and was found to be reduced at 1 week and 4 weeks in the ADM＋asmdr1 group, but it was stable in the ADM group. It was only 20% in the ADM＋asmdr1 group compared to the ADM group at the 4th week （P〈0.05）. Evidence of apoptosis was observed in the tumor xenograft cells treated with Adeno-asmdr1, but there was rare or no apoptosis in the group treated with ADM and PBS. CONCLUSION Adenovirus carrying antisense mdr1 RNA can partially reverse the MDR of HepG2/ADM cells and inhibit tumor growth by down-regulating mdr1 mRNA resulting in tumor cell apoptosis.     

7-Deoxynarciclasine shows promising antitumor efficacy by targeting Akt against hepatocellular carcinoma

Akt is a promising therapeutic target for cancer treatment. In our study, we have identified that 7-deoxynarciclasine (7-DONCS) is a potential inhibitor of Akt, which results in the repression of multiple oncogenic processes in hepatocellular carcinoma (HCC). We have found that 7-DONCS suppresses the growth of HCC by inducing the apoptotic and autophagic capacities, as well as by inhibiting epithelial–mesenchymal transition (EMT) in vitro and in vivo. Pretreatment of cells with specific autophagy inhibitor (Bafilomycin A1) or knockdown of endogenous LC-3B by siRNA strongly abrogates 7-DONCS-regulated apoptosis and EMT. Consequently, we have found that 7-DONCS selectively inhibits phospho-Akt (Ser473), and subsequent molecular docking reveals that 7-DONCS directly binds to the C-terminal domain of Akt. Overexpressing Akt significantly blocks these effects via 7-DONCS in HCC cells. Furthermore, 7-DONCS, by targeting Akt, exhibits a promising therapeutic effect in orthotopic hepatocellular tumors. Finally, higher p-Akt expression is associated with poor prognosis, and higher level of Akt was positively correlated with the enrichment of both apoptosis and autophagy downregulation, and EMT upregulation in HCC patients. These studies suggest that 7-DONCS serves as an attractive drug candidate by targeting Akt for future HCC therapy.     

重组人P53腺病毒增强肝癌细胞放疗的敏感性

摘 要 目的: 探讨重组人P53腺病毒(recombinant human adenovirus P53，rAdP53)对不同P53状态肝癌细胞生长的抑制和放射增敏作用。 方法: 以重组人P53腺病毒分别感染突变型P53肝癌细胞PLC/PRF/5和野生型P53肝癌细胞SMMC7721， Western blotting检测肝癌细胞P53蛋白表达，MTT法检测细胞存活率，台酚蓝染色绘制细胞生长曲线。肝癌细胞感染rAdP53 48 h后照射不同剂量的X射线，克隆形成法检测放射增敏比，TUNEL法检测细胞凋亡。 结果: 50 MOI rAd-P53转染PLC/PRF/5和SMMC7721细胞后转染效率分别为89.37%和87.53%，转染48 h可见P53蛋白高表达，MTT法显示细胞存活率分别为341%和35.44%，细胞生长曲线显示感染后第5天两种细胞生长抑制率分别为41.91%和17.03% (P<0.01)，PLC/PRF/5细胞的凋亡率\[(8.8±1.4)%\]显著高于SMMC7721 [(4.1±1.1)%] (P<0.01)。应用20 MOI的rAd-P53转染细胞48 h后加X射线(4 Gy)照射，PLC/PRF/5细胞的凋亡率为(26.9±5.6)%，显著高于SMMC7721细胞凋亡率(16.4±29)% (P<0.01)；20 MOI的rAdP53转染后加照射PLC/PRF/5和SMMC7721，细胞的放射增敏比SER(Dq)值分别为1.30和1.16；SER(D0)值分别为1.57和1.25。 结论: rAdP53能显著抑制人肝癌细胞生长、诱导细胞凋亡并提高细胞的放射敏感性，其对PLC/PRF/5细胞作用显著强于SMMC7721细胞；表明不同内源性P53状态的肝癌细胞对rAdP53治疗及其协同的放疗敏感性可能不同。     

溶瘤腺病毒SG7605-11R-P53对肝癌细胞的体外杀伤作用

目的:研究携带细胞穿膜肽11R和P53的溶瘤腺病毒SG7605-11R-P53对肝癌细胞的体外杀伤作用。方法:以本课题组前期实验构建的携细胞穿膜肽11R和P53的溶瘤腺病毒SG7605-11R-P53和不携11R的溶瘤腺病毒SG7605-P53感染肝癌细胞HepG2、SMMC-7721、Hep3B、Huh7和正常成纤维细胞株BJ,Western blotting检测感染后细胞P53和11R-P53的表达情况,TCID50法检测SG7605-11R-P53和SG7605-P53在肝癌细胞中的增殖能力,MTT法检测SG7605-11R-P53对肝癌细胞及正常细胞的杀伤作用。结果:SG7605-11R-P53和SG7605-P53能在肝癌细胞中高表达P53和11R-P53蛋白。SG7605-11R-P53可在HepG2、SMMC-7721、Hep3B和Huh7细胞中大量增殖,其增殖倍数是SG7605-P53的10~100倍,但在正常BJ细胞内几乎不增殖。SG7605-11R-P53在MOI=0.1时对Hep3B细胞的杀伤率达90%,对于正常BJ细胞只有当MOI=50时才有很弱的抑制作用;SG7605-11R-P53对4种肝癌细胞杀伤作用的大小依次为Hep3B、HepG2、Huh7和SMMC-7721细胞。结论:携带细胞穿膜肽11R和P53的SG7605-11R-P53溶瘤腺病毒体外对4种肝癌细胞株均有较好的靶向杀伤作用,尤其对Hep3B细胞的杀伤作用最强。     

Dissecting the roles of E1A and E1B in adenoviral replication and RCAd-enhanced RDAd transduction efficacy on tumor cells

Oncolytic viruses have recently received widespread attention for their potential in innovative cancer therapy. Many telomerase promoter-regulated oncolytic adenoviral vectors retain E1A and E1B. However, the functions of E1A and E1B proteins in the oncolytic role of replication-competent adenovirus (RCAd) and RCAd enhanced transduction of replication defective adenoviruses (RDAd) have not been addressed well. In this study, we constructed viruses expressing E1A alone, E1A plus E1B-19 kDa, and E1A plus E1B-19 kDa/55 kDa. We then tested their roles in oncolysis and replication of RCAd as well as their roles in RCAd enhanced transfection rate and transgene expression of RDAd in various cancer cells in vitro and in xenografted human NCI-H460 tumors in nude mice. We demonstrated that RCAds expressing E1A alone and plus E1B-19 kDa exhibited an obvious ability in replication and oncolytic effects as well as enhanced RDAd replication and transgene expression, with the former showed more effective oncolysis, while the latter exhibited superior viral replication and transgene promotion activity. However, RCAd expressing both E1A and E1B-19 kDa/55 kDa was clearly worst in all these abilities. The effects of E1A and E1B observed through using RCAd were further validated by using plasmids expressing E1A alone, E1A plus E1B-19 kDa, and E1A plus E1B-19 kDa/55 kDa proteins. Our study provided evidence that E1A was essential for inducing replication and oncolytic effects of RCAd as well as RCAd enhanced RDAd transduction, and expression of E1B-19 kDa other than E1B-55 kDa could promote these effects. E1B-55 kDa is not necessary for the oncolytic effects of adenoviruses and somehow inhibits RCAd-mediated RDAd replication and transgene expression.     

塞来昔布联合IL-24武装的溶瘤腺病毒抗膀胱癌作用的体外研究

 目的：评估塞来昔布联合ZD55-IL-24对尿路上皮细胞癌T24的选择性杀伤效能。 方法：荧光显微镜观察ZD55-EGFP对细胞的转染效率。RT-PCR法测IL-24 mRNA在细胞中的表达。MTT法测塞来昔布联合 ZD55-IL-24对肿瘤细胞选择性抑制作用。流式细胞术检测细胞凋亡。 结果： ZD55-EGFP感染细胞后,在相同时间下T24中的荧光强度明显高于正常细胞。ZD55-IL-24转然后在相同时间下T24中IL-24mRNA表达量均高于HUVEC（t=-12.54,P<0.01）。ZD55-IL-24与塞来昔布联合用药对T24的抑制率最高（P<0.01）。T24细胞各组的抑制率也明显高于HUVEC组（F＝251.35,P<0.01）。联合用药组的细胞凋亡率也明显高于单用药组;T24细胞组凋亡率明显高于HUVEC组（P<0.001）。 结论：塞来昔布与ZD55-IL-24联合用药能最大程度地抑制T24细胞的增殖而对正常细胞影响轻微。这种抑制作用可能与细胞凋亡有关。     

携带p16基因增殖缺陷型腺病毒对胃癌细胞皮下移植瘤的治疗作用

目的:研究携带p16基因的增殖缺陷型腺病毒载体对裸鼠皮下胃癌细胞移植瘤的抗肿瘤活性。方法:PCR扩增p16cDNA,构建腺病毒载体pSuCMV-p16表达质粒,在293细胞内重组增殖缺陷型腺病毒AdCMV-p16;建立胃腺癌细胞SGC-7901皮下移植瘤裸鼠模型,分为3组(AdCMV-p16组、Ad-LacZ组、空白对照组),以2×108pfu/100μl的重组腺病毒Ad-CMV-p16直接瘤内多点注射,隔日1次,共5次,空白对照组以等量病毒保存液注射,定时测量瘤体生长情况,并以p16免疫组化、TUNEL凋亡检测等观察AdCMV-p16抗肿瘤的疗效。结果:携带p16基因的增殖缺陷型腺病毒AdCMV-p16对胃腺癌裸鼠移植瘤有明显的抑制作用,抑瘤率为58.12%,而对照病毒Ad-LacZ对胃癌移植瘤的抑瘤率仅为4.26%;病理学检查显示,病毒治疗的癌组织中细胞坏死以凋亡为主,癌细胞中检测到p16基因的表达。结论:携带p16基因的增殖缺陷型腺病毒能恢复胃癌细胞中p16基因的表达,对胃癌移植瘤生长有明显的抑制作用。     

携带p16基因增殖缺陷型腺病毒对胃癌细胞皮下移植瘤的治疗作用

诱导免疫原性肿瘤细胞死亡是抗肿瘤化疗药物的目标之一,该作用可以通过免疫系统的“旁观者效应”根除对化疗药物抵抗的肿瘤细胞和肿瘤干细胞。蒽环类化疗药物(anthracyclin)在激发机体免疫原性的抗肿瘤反应方面具有显著的效应,但DNA损伤类化疗药物如依托泊苷(etoposide)和丝裂霉素C(mitomycin C)则不能有效地诱导免疫原性的细胞死亡。蒽环类化疗药物是如何使机体免疫系统能够识别肿瘤细胞,继而激发机体抗肿瘤效应呢?该研究的结果表明,蒽环类化疗药物能够快速诱导促凋亡的钙网蛋白(calreticulin,CRT)从胞质转位到胞膜,从而被树突状细胞表…