53基因及CAR受体对ONYX-015肿瘤杀伤作用的影响

目的:利用肿瘤特异性增殖型腺病毒ONYX-015分别感染具有柯萨奇病毒和腺病毒联合受体(CAR)水平正常、p53正常或突变的,以及CAR水平低下、p53突变的肿瘤细胞株,研究ONYX 015对这些肿瘤细胞的特异性增殖及杀伤能力。方法:以正常的肝细胞株L02作为对照,用细胞病变效应(CPE)实验观察ONYX-015对细胞的选择性杀伤效应;病毒增殖实验检测野生型腺病毒(Ad5)、ONYX 015在多种肿瘤细胞中的增殖能力。结果:ONYX 015对正常的肝细胞L02无杀伤性,但能够有效地杀伤p53突变的肝癌细胞Hep3B、p53正常的肝癌细胞HepG2及肺癌细胞A549,不能杀伤p53突变的人乳腺癌细胞株MDA-MB 231。在CAR受体水平正常的癌细胞株Hep3B、HepG2和A549中,Ad5和ONYX-015均可增殖。在CAR受体水平低下、p53突变的人乳腺癌细胞株MDA-MB 231中,两种病毒均不增殖。结论:CAR受体对ONYX-015的增殖力起着至关重要的作用。在CAR受体水平正常的前提下,无论肿瘤细胞的p53基因正常与否,ONYX-015均可以有效增殖并杀伤细胞;相反,如果CAR受体水平低下,即使该种肿瘤细胞p53基因突变,ONYX-015在该细胞中的增殖力也会受到限制。ONYX-015不杀伤CAR受体及p53基因均正常的正常肝细胞。     

肿瘤增殖腺病毒ONYX-015的实验研究及临床研究进展

肿瘤增殖病毒在肿瘤细胞内的感染、复制及溶解细胞作用增强,而在正常细胞内这种能力减弱甚至消失.E1b55 kD蛋白缺失的肿瘤增殖病毒是第1个用于肿瘤临床的增殖病毒,也是最成功的肿瘤病毒治疗系统,并于1999年进入Ⅲ期临床试验.现综述ONYX-015的实验研究和临床研究进展.     

肿瘤增殖腺病毒ONYX-015的实验研究及临床研究进展

肿瘤增殖病毒在肿瘤细胞内的感染、复制及溶解细胞作用增强 ,而在正常细胞内这种能力减弱甚至消失。E1b5 5kD蛋白缺失的肿瘤增殖病毒是第 1个用于肿瘤临床的增殖病毒 ,也是最成功的肿瘤病毒治疗系统 ,并于 1999年进入Ⅲ期临床试验。现综述ONYX 0 15的实验研究和临床研究进展     

腺病毒载体转染p53基因提高肿瘤放射敏感性的实验研究进展

几十年来,许多放射生物学和放射肿瘤学专家致力于寻找提高肿瘤放射敏感性的理想药物,试用了生物还原剂、亲电子化合物、修复抑制剂等诸多药物,均因效果欠佳或毒性大而未能广泛应用于临床［１］。近年来分子生物学迅猛发展,为肿瘤学和放射肿瘤学研究提供了新的线索。癌...     

腺病毒介导的p53基因对喉癌细胞生长的抑制作用

目的探索ｐ５３基因在喉癌基因治疗方面的可行性。方法以人喉癌细胞系Ｈｅｐ－２为实验对象,将载有人野生型ｐ５３ｃＤＮＡ并含巨细胞病毒（ＣＭＶ）启动子的重组腺病毒（Ａｄ５ＣＭＶ－ｐ５３）感染Ｈｅｐ－２细胞及肿瘤组织,体内外实验观察Ａｄ５ＣＭＶ－ｐ５３对Ｈｅｐ－２细胞生长的影响。结果当Ａｄ５ＣＭＶ－ｐ５３在１００ＭＯＩ效靶比时,全部Ｈｅｐ－２细胞得到转染。感染２天后ｐ５３蛋白表达达到高峰,Ｈｅｐ－２生长受到明显的抑制。Ａｄ５ＣＭＶ－ｐ５３感染Ｈｅｐ－２细胞在裸鼠中失去致瘤性。瘤内注射Ａｄ５ＣＭＶ－ｐ５３后,荷瘤裸鼠的肿瘤体积明显减小。结论Ａｄ５ＣＭＶ－ｐ５３转导野生型ｐ５３基因可能是一种有效的喉癌基因治疗途径。     

腺病毒介导HSV—tk自杀基因联合野生型p53基因对直肠癌细胞的杀伤作用

目的 观察重组腺病毒介导单纯疱疹病毒胸苷激酶（HSV－tk)基因联合人野生型p53基因共转染,对直肠癌细胞杀伤作用。方法 构建重组腺病毒质粒pAdCMV-Link1(tk/p53)、pAdCMV-Link(tik),pAdCMV-Link(p53),分别感染p53炎变的人直肠癌细胞SW837。进行细胞集落形成实验、细胞存活率的测定和裸鼠移植瘤治疗实验,观察HSV－tk/GCV系统与野生p53基因联合对肿瘤细胞的杀伤作用。结果 应用pAdCMV-Link1(tk/p53),pAdCMV-Link(-),pAdCMV-Link(tk),pAdCMV-Link(p53)重组腺病毒感染SW837细胞,加入GCV,各组细胞集落数分别为8、95、40、70。pAdCMV-Link(CD/53)组肿瘤细胞集落形成减少、细胞存活率显著下降（P＜0．01）。裸鼠移植肿瘤生长抑制率分别为76．5％、0．8％、55．8％、23．2％,pACMV-Link(tk/p53)重组腺病毒对肿瘤的抑制作用最强。结论 HSV－tk自杀基因与野生型p53基因共转染,对肿瘤细胞有更强的杀伤作用。     

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…     

乳腺癌雌孕激素受体与C-erbB-2、p53、nm23基因表达及相关分析

目的观察乳腺癌组织中雌、孕激素受体(ER、PR)与C-erbB-2、p53、nm23基因表达及其相互关系,及乳腺癌淋巴结转移与基因表达关系.方法应用免疫组织化学方法对85例乳腺癌进行了ER、PR、CerbB-2、p53、nm23检测,结果作统计学分析.结果(1)ER、PR阳性表达率分别为63.52%和72.94%;(2)C-erbB-2、p53、nm23的表达率各为68.23%、32.94%、63.52%;(3)ER、PR阳性患者的C-erbB-2或p53的阳性表达明显低于ER、PR阴性患者(P＜0.05);(4)淋巴结有转移的乳腺癌患者nm23阳性表达明显低于无淋巴结转移的患者(P＜0.05),p53表达则在有淋巴结转移者的乳癌中表达高(P＜0.01).结论ER、PR与C-erbB-2、p53、nm23这两种不同特性产物在乳腺癌组织中有一定的内在联系,p53、nm23的阳性表达对判断乳癌的肿瘤转移及预后有重要意义.     

p53基因增加肿瘤放射治疗敏感性的机制

在肿瘤放疗过程中,p53基因的正常功能对肿瘤细胞的凋亡和提高放射敏感性起了关键性作用。野生型p53基因通过激活或抑制一系列基因,使肿瘤细胞周期阻滞,抑制肿瘤细胞放射损伤的修复,促进肿瘤细胞的凋亡,以及在乏氧环境中对促进肿瘤细胞凋亡至关重要,增强了肿瘤细胞对放疗的敏感性。     

Interactions between adenovirus proteins and the p53 pathway: the development of ONYX-015

dl1520 (ONYX-015) is an adenovirus mutant that lacks the E1b 55K gene. As a result it cannot neutralize p53. Therefore dl1520 should only grow in cells that lack p53, and should replicate selectively in cancer cells. However, there is no correlation between replication and p53 status, in cancer cells. This is for two reasons: (1) E1B 55K has additional functions, that are necessary in some tumor cells and not in others. (2) p53 function can be lost by alternative mechanisms such as loss of p14ARF. In normal cells, dl1520 induces p53, and is generally strongly attenuated for replication. ONYX-015 is currently being tested in clinical trials, and is a promising new therapeutic agent in cancer.     

ONYX-015 selectivity and the p14ARF pathway.

ONYX-015, dl1520, is an adenovirus that lacks the E1B 55K gene and therefore lacks the capacity to neutralize p53 during infection. This virus induces high levels of p53 and fails to grow efficiently in primary epithelial cells. However, it does replicate in many tumor cells, including those expressing wild-type p53. In these cells, ONYX-015 fails to induce active p53. This is because the pathway from Ela to p53 is disrupted through loss of p14ARF. We propose that high levels of Mdm2 activity resulting from loss of p14ARF, and high levels of Mdm2 protein resulting from activated Ras prevent accumulation of functional p53 during infection of tumor cells that retain wild-type p53.     

p14(ARF) modulates the cytolytic effect of ONYX-015 in mesothelioma cells with wild-type p53

ONYX-015 has been reported to kill selectively tumor cells lacking functional p53. Genetic alterations of INK4a/ARF locus, which is a predominant event in malignant pleural mesothelioma, may result in loss of p14(ARF) and subsequent disruption of p53 pathway in cancer cells. In the present study, ONYX-015 was able to kill three mesothelioma cell lines (H28, H513, and 211H) with wild-type p53 but lacking p14(ARF). In contrast, MS-1 mesothelioma cells, which expressed both p53 and p14(ARF), were resistant to ONYX-015. Introducing p14(ARF) gene into the H28 cell, a mesothelioma cell without p14(ARF) expression, significantly increased the resistance of this cell line to the cytolytic effect of ONYX-015. Our results suggest that human mesotheliomas with wild-type p53 yet lacking p14(ARF) are potential candidates for ONYX-015 therapy.     

Late viral RNA export, rather than p53 inactivation, determines ONYX-015 tumor selectivity

ONYX-015 is an adenovirus that lacks the E1B-55K gene product for p53 degradation. Thus, ONYX-015 was conceived as an oncolytic virus that would selectively replicate in p53-defective tumor cells. Here we show that loss of E1B-55K leads to the induction, but not the activation, of p53 in ONYX-015-infected primary cells. We use a novel adenovirus mutant, ONYX-053, to demonstrate that loss of E1B-55K-mediated late viral RNA export, rather than p53 degradation, restricts ONYX-015 replication in primary cells. In contrast, we show that tumor cells that support ONYX-015 replication provide the RNA export function of E1B-55K. These data reveal that tumor cells have altered mechanisms for RNA export and resolve the controversial role of p53 in governing ONYX-015 oncolytic selectivity.     

In vivo antitumor activity of ONYX-015 is influenced by p53 status and is augmented by radiotherapy

The E1B-deleted, replication-competent ONYX-015 (dl1520) adenovirus was originally described as being able to selectively kill p53-deficient cells due to a requirement of p53 inactivation for efficient viral replication. This hypothesis has become controversial because subsequent in vitro studies have demonstrated that the host range specificity of ONYX-015 is independent of p53 gene status. Using a pair of isogenic cell lines that differ only in their p53 status, we demonstrate here that although ONYX-015 can replicate in both p53 wild-type and mutant cells in vitro, the virus demonstrates significantly greater antitumor activity against mutant p53 tumors in vivo. Moreover, ONYX-015 viral therapy can be combined with radiation to improve tumor control beyond that of either monotherapy. The results demonstrate that ONYX-015 can discern in vivo between tumors having a different p53 status and that it may be an effective neoadjuvant to radiation therapy.     

Phase II clinical trial of intralesional administration of the oncolytic adenovirus ONYX-015 in patients with hepatobiliary tumors with correlative p53 studies.

PURPOSE: ONYX-015 is a genetically modified adenovirus with a deletion of the E1B early gene and is therefore designed to replicate preferentially in p53-mutated cells. A Phase II trial of intralesional ONYX-015 was conducted in patients with hepatobiliary tumors to determine the safety and efficacy of such a treatment. EXPERIMENTAL DESIGN: All patients had biopsy-proven, measurable tumors of the liver, gall bladder, or bile ducts that were beyond the scope of surgical resection. Patients received intralesional injections of ONYX-015 at either 6 x 10(9) or 1 x 10(10) plaque-forming units/lesion up to a total dose of 3 x 10(10) plaque-forming units, and i.p. injections were allowed in patients with malignant ascites. The status of p53 was assessed by immunohistochemistry or Affymetrix GeneChip microarray analysis. Studies were conducted for viral shedding and for the presence of antiadenoviral antibodies before and after the injection of ONYX-015. Patients were assessed for response and toxicity. RESULTS: Twenty patients were enrolled, and 19 patients were eligible. Half of the patients had primary bile duct carcinomas. Serious toxicities (> grade 2) were uncommon and included hepatic toxicity (three patients), anemia (one patient), infection (one patient), and cardiac toxicity (one patient, atrial fibrillation). Sixteen patients were evaluable for response. Among these evaluable patients, 1 of 16 (6.3%) had a partial response, 1 of 16 (6.3%) had prolonged disease stabilization (49 weeks), and 8 of 16 (50%) had a >50% reduction in tumor markers. Of the 19 eligible patients, 18 (94.7%) had specimens available for p53 analysis. Fifteen of these 18 patients (83.3%) had evidence of p53 mutation by one or both methods, although the methods correlated poorly. Viral shedding was confined to bile (two of two patients) and ascites (four of four patients). Pretreatment adenoviral antibodies were present in 14 of 14 patients and increased by 33.2% after ONYX-015 treatment. CONCLUSIONS: Intralesional treatment with ONYX-015 in patients with hepatobiliary tumors is safe and well tolerated, and some patients had evidence of an anticancer effect. The high incidence of p53 mutations in these tumors makes this a logical population in which to test this therapy but precludes definitive evaluation about the necessity of a p53 mutation for ONYX-015 clinical activity.     

Oncolytic activity of the E1B-55 kDa-deleted adenovirus ONYX-015 is independent of cellular p53 status in human malignant glioma xenografts

Treatment of malignant gliomas remains a major challenge in adults and children because of high treatment failure. The E1B 55 kDa-gene deleted adenovirus, ONYX-015 (ONYX Pharmaceuticals), was demonstrated to replicate selectively in and lyse tumor cells. Currently ongoing clinical trials of ONYX-015 in head and neck tumors are promising. Here, we demonstrate ONYX-015-mediated cell lysis and antitumor activity in three of four s.c. human malignant glioma xenografts deriving from primary tumors. Intratumoral injections of ONYX-015, 1 x 10(8) plaque-forming units daily for 5 consecutive days, yielded significant tumor growth delay in the p53 mutant xenografts IGRG88 and the p53 wild-type IGRG93 and IGRG121 treated at an advanced tumor stage. The p53 wild-type tumors IGRG93 and IGRG121 experienced 45% and 82% complete tumor regressions. Four and 8 of 11 animals, respectively, survived tumor free 4 months after treatment. Widespread intratumoral adenoviral replication was observed in tumor cells of these two xenografts compared with only scattered replication in the p53-mutant tumors. In addition to a fast tumor growth rate, wild-type p53 status was associated with increased antitumor activity of the E1B-attenuated virus, and induction of functional p53 may therefore determine adenoviral cytolysis in tumor cells. In conclusion, ONYX-015 displayed a major antitumor activity in human xenografts derived from primary malignant glioma supporting its development in the treatment of these highly malignant tumors.     

Antitumor effect of adenovirus-mediated Bax gene transfer on p53-sensitive and p53-resistant cancer lines

Antitumor effects of the proapoptotic Bax gene have been evaluated in vitro and in vivo by a binary adenovirus system expressing the human Bax gene. Overexpression of the Bax gene in cultured cell lines from human lung carcinoma results in caspase activation, apoptosis induction, and cell growth suppression. Intratumoral injection of adenovirus vector expressing the Bar gene suppressed growth of human lung cancer xenografts established in nude mice. Histological examination of tumors from mice treated with the Bax gene demonstrated high levels of Bax expression and extensive apoptosis in tumors. In comparison with the treatment by an adenoviral vector expressing human p53, the Bax gene can effectively suppress tumor growth in both p53-sensitive and p53-resistant human lung carcinoma cell lines. Toxicity was not detected in liver and other systems in animals treated intralesionally with the Bax gene. Therefore, our results suggest that the Bar gene may be useful in cancer treatment.