Cilengitide induces cellular detachment and apoptosis in endothelial and glioma cells mediated by inhibition of FAK/src/AKT pathway

Background

To develop a novel therapeutic strategy for human pancreatic cancer using a midkine promoter-based conditionally replicating adenovirus.

Methods

We examined midkine mRNA expression and midkine protein expression by seven human pancreatic cancer cell lines (AsPC-1, BxPC-3, CFPAC-1, HPAC, MIAPaCa-2, PANC-1, and Suit-2), as well as by non-cancerous pancreatic tissue and pancreatic cancers. Midkine promoter activity was measured in cancer cell lines by the dual luciferase reporter assay. Adenoviral transduction efficiency was assessed by fluorescent staining of cancer cell lines using adenovirus type 5 containing the green fluorescent protein gene (Ad5GFP). Replication of adenovirus type 5 containing the 0.6 kb midkne promoter (Ad5MK) was assessed by the detection of E1 protein in cancer cell lines. The cytotoxicity of Ad5MK for cancer cells was evaluated from the extent of growth inhibition after viral infection. Infection and replication were also assessed in nude mice with subcutaneous Suit-2 tumors by intratumoral injection of Ad5MK, Ad5GFP, or vehicle. E1a mRNA expression in the treated tumors and expression of the replication-specific adenoviral hexon protein were evaluated. Finally, the anti-tumor activity of Ad5MK against intraperitoneal xenografts of Suit-2 pancreatic cancer cells was examined after intraperitoneal injection of the virus.

Results

Both midkine mRNA expression and midkine protein expression were strong in AsPC-1 and CFPAC-1 cell liens, moderate in BxPC-3, HPAC, and Suit-2 cell lines, and weak in PANC-1 and MIAPaCa-2 cell lines. Expression of midkine mRNA was significantly stronger in pancreatic cancers than in non-cancerous pancreatic tissues. The relative luciferase activity mediated by the 0.6 kb midkne fragment in AsPC-1, PANC-1, and Suit-2 cell lines was approximately 6 to 20 times greater than that in midkne-negative MIAPaCa-2 cell lines. Pancreatic cancer cell lines exhibited a heterogeneous adenoviral transduction profile. E1A expression was higher in cell lines with strong midkine expression than in cell lines with weak midkine expression. Ad5MK showed much greater cytotoxicity for midkine-expressing Suit-2 and PANC-1 cell lines than for midkine-negative MIAPaCa-2 cell lines. In the Suit-2 subcutaneous xenograft model, expression of E1A was detected in Ad5MK-treated tumors, but not in untreated and Ad5GFP-treated tumors. In the Suit-2 intraperitoneal xenograft model, the Ad5MK group survived for significantly longer than the Ad5GFP, PBS, and untreated groups.

Conclusion

Ad5MK has an anti-tumor effect against human pancreatic cancer cell lines that express midkine mRNA. Midkine promoter-based conditionally replicative adenovirus might be a promising new gene therapy for pancreatic cancer.     

A novel assay to assess primary human cancer infectibility by replication-selective oncolytic adenoviruses.

PURPOSE: Replication-selective oncolytic adenoviruses hold promise for cancer treatment, but the predictive use of cell lines, dissociated tumor tissue, and animal models for efficacy against primary cancers are unclear. To further evaluate cytotoxicity and the potential for efficacy of replication-competent adenoviruses we therefore developed a novel methodology using primary human cancer specimens ex vivo; ovarian, colon, rectal, and breast carcinomas were included. EXPERIMENTAL DESIGN: Tissue culture conditions were developed to maintain viability of adenocarcinomas ex vivo for 48 hours postsurgery. Explants were infected by replication-competent (wild type 5 and E1A mutant dl922-947) and replication-defective (dl312) adenoviruses; early (E1A) and late (hexon) viral gene expression, alphav integrins, coxsackievirus and adenovirus receptor (CAR) and tissue viability were assessed by immunohistochemistry and histopathology. Viral replication was verified by replication assays on selected samples. RESULTS: Viral gene expression varied dramatically among cancer specimens (n = 41). With Ad5, hexon expression was high in 8 of 11 tested specimens, whereas E1A levels were detectable in 16 of 27 tumor explants. Viral gene expression, distribution, and cytopathic effects were greater postinfection with dl922-947. Specimens that supported early gene expression (E1A) also supported viral replication in 13 of 14 tested cases, determined by recovery of infectious units. As predicted, the replication-defective adenovirus dl312 was not associated with viral gene expression. CONCLUSIONS: Primary human tumor tissue remained viable when cultured ex vivo enabling evaluation of viral mutants in tissue with intact morphology. This assay may have great use in determining treatment-sensitive cancers and assess specific oncolytic mutants in individual cases.     

Heat shock protein 72 expression allows permissive replication of oncolytic adenovirus dl1520 (ONYX-015) in rat glioblastoma cells

In this study we have made novel observations with regards to potentiation of the tumoricidal activity of the oncolytic adenovirus, dl1520 (ONYX-015) in rat glioblastoma cell lines expressing heat shock protein 72 (HSP72) due to permissive virus replication. ONYX-015 is a conditionally replicating adenovirus that is deleted for the E1B 55 kDA gene product whose normal function is to interact with cell-cycle regulatory proteins to permit virus replication. However, many murine and rodent cell lines are not permissive for adenovirus replication. Previously, it has been reported that the heat shock response is necessary for adenovirus replication and that induction of heat shock proteins is mediated by E1 region gene products. Therefore, we hypothesized that HSP72 expression may allow for permissive replication of ONYX-015 in previously non-permissive cells. Rat glioma cell lines 9L and RT2 were transfected with a plasmids expressing HSP72 or GFP. After infection with ONYX-015, no tumoricidal activity is observed in GFP expressing cell lines despite adequate transduction. In contrast, HSP72 transfected cells show cytopathic effects by 72 hours and greater than 75% loss of viability by 96 hours. Burst assays show active virus replication in the HSP72 expressing cell lines. Therefore, 9L-HSP72 and RT2-HSP72 are ideal models to evaluate the efficacy of ONYX-015 in an immunocompetent rat model. Our study has implications for creating rodent tumor models for pre-clinical studies with E1 region deleted conditionally replicating adenovirus.     

Midkine promoter-based conditionally replicative adenovirus therapy for midkine-expressing human pancreatic cancer

Background

To develop a novel therapeutic strategy for human pancreatic cancer using a midkine promoter-based conditionally replicating adenovirus.

Methods

We examined midkine mRNA expression and midkine protein expression by seven human pancreatic cancer cell lines (AsPC-1, BxPC-3, CFPAC-1, HPAC, MIAPaCa-2, PANC-1, and Suit-2), as well as by non-cancerous pancreatic tissue and pancreatic cancers. Midkine promoter activity was measured in cancer cell lines by the dual luciferase reporter assay. Adenoviral transduction efficiency was assessed by fluorescent staining of cancer cell lines using adenovirus type 5 containing the green fluorescent protein gene (Ad5GFP). Replication of adenovirus type 5 containing the 0.6 kb midkne promoter (Ad5MK) was assessed by the detection of E1 protein in cancer cell lines. The cytotoxicity of Ad5MK for cancer cells was evaluated from the extent of growth inhibition after viral infection. Infection and replication were also assessed in nude mice with subcutaneous Suit-2 tumors by intratumoral injection of Ad5MK, Ad5GFP, or vehicle. E1a mRNA expression in the treated tumors and expression of the replication-specific adenoviral hexon protein were evaluated. Finally, the anti-tumor activity of Ad5MK against intraperitoneal xenografts of Suit-2 pancreatic cancer cells was examined after intraperitoneal injection of the virus.

Results

Both midkine mRNA expression and midkine protein expression were strong in AsPC-1 and CFPAC-1 cell liens, moderate in BxPC-3, HPAC, and Suit-2 cell lines, and weak in PANC-1 and MIAPaCa-2 cell lines. Expression of midkine mRNA was significantly stronger in pancreatic cancers than in non-cancerous pancreatic tissues. The relative luciferase activity mediated by the 0.6 kb midkne fragment in AsPC-1, PANC-1, and Suit-2 cell lines was approximately 6 to 20 times greater than that in midkne-negative MIAPaCa-2 cell lines. Pancreatic cancer cell lines exhibited a heterogeneous adenoviral transduction profile. E1A expression was higher in cell lines with strong midkine expression than in cell lines with weak midkine expression. Ad5MK showed much greater cytotoxicity for midkine-expressing Suit-2 and PANC-1 cell lines than for midkine-negative MIAPaCa-2 cell lines. In the Suit-2 subcutaneous xenograft model, expression of E1A was detected in Ad5MK-treated tumors, but not in untreated and Ad5GFP-treated tumors. In the Suit-2 intraperitoneal xenograft model, the Ad5MK group survived for significantly longer than the Ad5GFP, PBS, and untreated groups.

Conclusion

Ad5MK has an anti-tumor effect against human pancreatic cancer cell lines that express midkine mRNA. Midkine promoter-based conditionally replicative adenovirus might be a promising new gene therapy for pancreatic cancer.     

In vivo imaging of adenovirus transduction and enhanced therapeutic efficacy of combination therapy with conditionally replicating adenovirus and adenovirus-p27

Gene therapy is hampered by poor gene transfer to the tumor mass. We previously proposed a combination adenoviral gene therapy containing a conditionally replicating adenovirus (CRAD) expressing mutant E1 (delta24RGD) and a replication-defective E1-deleted adenovirus to enhance the efficiency of gene transfer. Mutant E1 expressed by delta24RGD enables the replication of replication-defective adenoviruses in tumors when cancer cells are co-infected with both viruses. In this study, gene transfer rates in xenografts tumors were monitored by bioluminescence in cells infected with the replication-defective adenovirus-luciferase (ad-luc). Tumor masses treated with CRAD + ad-luc showed dramatically stronger and more prolonged luciferase expression than ad-luc-treated tumors and this expression spread through the entire tumor mass without significant systemic spread. Transduction with CRAD + replication-defective adenovirus-p27 increased the expression of p27 by 24-fold versus transduction with ad-p27 alone. Treatment of a lung cancer cell line and of established lung cancer xenografts with CRAD + adenovirus-p27 also induced stronger growth suppression than treatment with either virus alone. These findings confirm the selective replication of E1-deleted adenovirus containing a therapeutic gene due to the presence of mutant E1 produced by delta24RGD in tumors. Moreover, this replication increased the therapeutic gene transfer rate and enhanced its antitumor effects.     

Survivin-responsive conditionally replicating adenovirus exhibits cancer-specific and efficient viral replication

Although a conditionally replicating adenovirus (CRA) exhibiting cancer-selective replication and induction of cell death is an innovative potential anticancer agent, current imperfections in cancer specificity and efficient viral replication limit the usefulness of this technique. Here, we constructed survivin-responsive CRAs (Surv.CRAs), in which expression of the wild-type or mutant adenoviral early region 1A (E1A) gene is regulated by the promoter of survivin, a new member of the inhibitor of apoptosis gene family. We explored the cancer specificity and effectiveness of viral replication of Surv.CRAs, evaluating their potential as a treatment for cancer. The survivin promoter was strongly activated in all cancers examined at levels similar to or even higher than those seen for representative strong promoters; in contrast, low activity was observed in normal cells. Surv.CRAs efficiently replicated and potently induced cell death in most types of cancer. In contrast, minimal viral replication in normal cells did not induce any detectable cytotoxicity. A single injection of Surv.CRAs into a preestablished tumor expressing survivin, even at relatively low levels, induced significant tumor death and inhibition of tumor growth. Furthermore, Surv.CRAs were superior to telomerase-dependent CRAs, one of the most effective CRAs that have been examined to date, both in terms of cancer specificity and efficiency. Thus, Surv.CRAs are an attractive potential anticancer agent that could effectively and specifically treat a variety of cancers.     

Evaluation of E1B gene-attenuated replicating adenoviruses for cancer gene therapy

Gene-attenuated replication-competent adenoviruses are emerging as a promising new modality for the treatment of cancer. For the aim of improving adenoviral vectors for cancer gene therapy, we have constructed genetically attenuated adenoviral vectors with different combinations of E1B genes and investigated the possibility of enhanced oncolytic and replication effects of these engineered replication-competent adenoviruses. We show here that the cytolytic potency of each gene-attenuated replicating adenovirus differed significantly depending on the presence or deletion of E1B 55 kDa and E1B 19 kDa function. More specifically, among the constructed vectors (Ad-deltaE1B19, Ad-deltaE1B55, Ad-deltaE1B19/55, and Ad-wt), E1B 19 kDa-inactivated adenovirus (Ad-deltaE1B19) was the most potent against all tumor cells tested, inducing the largest-sized plaques and marked CPE. Further, cells infected with either Ad-deltaE1B19 or E1B19/55 kDa-deleted adenovirus (Ad-deltaE1B19/55) showed complete cell lysis with disintegrated cellular structure, whereas cells infected with Ad-wt maintained intact cellular and nuclear membrane with properly structured organelles. TUNEL and DNA fragmentation assay also revealed that the Ad-deltaE1B19 or Ad-deltaE1B19/55 adenovirus-infected cells showed more profound induction of apoptosis in comparison to wild-type adenovirus-infected cells. The presence of E1B 55 kDa gene was required for efficient viral replication and deletion of E1B 19 kDa function in replicating adenovirus-induced apoptosis, leading to increased cytopathic effects. Moreover, Ad-deltaE1B19 adenovirus showed a better antitumor effect than other E1B-attenuated adenoviruses. Taken together, the replicating adenoviruses deleted in E1B 19 kDa function may serve as an improved vector for anticancer gene therapy in combination with apoptosis-inducing modalities such as chemotherapeutic agents and radiation therapy.     

Heat shock phenocopies E1B-55K late functions and selectively sensitizes refractory tumor cells to ONYX-015 oncolytic viral therapy

ONYX-015 is an E1B-55K-deleted adenovirus that has promising clinical activity as a cancer therapy. However, many tumor cells fail to support ONYX-015 oncolytic replication. E1B-55K functions include p53 degradation, RNA export, and host protein shutoff. Here, we show that resistant tumor cell lines fail to provide the RNA export functions of E1B-55K necessary for ONYX-015 replication; viral 100K mRNA export is necessary for host protein shutoff. However, heat shock rescues late viral RNA export and renders refractory tumor cells permissive to ONYX-015. These data indicate that heat shock and late adenoviral RNAs may converge upon a common mechanism for their export. Moreover, these data suggest that the concomitant induction of a heat shock response could significantly improve ONYX-015 cancer therapy.     

Conditionally replicating adenovirus improves gene replication efficiency and anticancer effect of E1‐deleted adenovirus carrying TRAIL in head and neck squamous cell carcinoma

To overcome the low efficiency of gene therapy, we combined a conditionally replicating adenovirus (CRAd) and an adenoviral vector with a therapeutic gene. CRAd has an oncolytic activity in cancer cells with abnormal Rb activity and helps the replication of therapeutic genes incorporated in the E1‐deleted adenovirus. We investigated the anticancer effect of a combination of CRAd and adenovirus carrying tumor necrosis factor‐related apoptosis inducing ligand (ad‐TRAIL). We expected to see increased gene expression in cancer cells as well as an antitumor effect. With the combined application of CRAd and ad‐luciferase in head and neck cancer cell lines, we observed considerably increased luciferase activity that was 10‐ to 50‐fold greater than with ad‐luciferase alone. The combination of CRAd and ad‐TRAIL showed significant suppression of growth in cell lines and increased the sub‐G₁ portion of cells 30‐fold compared to any single treatment. The expression of TRAIL was highly amplified by the combined treatment and was accompanied by expression of molecules related to apoptosis. In a xenograft animal model, mice treated with CRAd and ad‐TRAIL showed complete regression of established tumors, whereas mice treated with CRAd or ad‐TRAIL alone did not. In conclusion, this combined strategy using CRAd and adenovirus carrying a therapeutic gene increased the gene transfer rate and enhanced antitumor effects. We expect that this combination strategy could be extended to a multitarget cancer gene therapy by combining multiple adenoviruses and CRAd. (Cancer Sci 2009)     

The presence of the adenovirus E3 region improves the oncolytic potency of conditionally replicative adenoviruses.

PURPOSE: The initial development of conditionally replicative adenoviruses (CRAds) for cancer treatment has aimed at achieving selective replication in and killing of malignant cells. Other aspects such as the potentiation of the cytolytic capacity have also been investigated but still require new endeavors. As an extension of our prior work, we analyzed the effect of the E3 region, which includes the adenovirus death protein, in the context of CRAd oncolytic potency. EXPERIMENTAL DESIGN: We constructed E3-positive (E3+) and E3-negative (E3-) variants of the previously characterized CRAd, Ad5-Delta 24, and its infectivity enhanced version, Ad5-Delta 24RGD, and compared their oncolytic effect in human cancer cell lines infected with 0.01 viral particle/cell and in s.c. xenografts of A549 human lung cancer cells injected intratumorally with a single dose of 10(7) adenoviral particles in immunodeficient mice. RESULTS: The in vitro experiments showed that the E3+ viruses kill tumor cells 1.6-20 times more effectively in different cell lines. As well, the in vivo study demonstrated that the administration of E3+ CRAds resulted in a more potent oncolytic effect compared with the same dose of their E3- counterparts 35 days after virus administration. Moreover, a time course study of virus replication within the tumor xenografts established a correlation between higher in situ propagation of E3+ CRAds and tumor growth inhibition compared with E3- viruses. CONCLUSIONS: These results indicate that the presence of E3 can enhance the antitumor potency of CRAds over and above the levels conferred by the enhancement of infectivity via Arg-Gly-Asp (RGD).     

选择性增殖腺病毒CNHK500治疗乳腺癌的实验研究

目的: 观察选择性增殖腺病毒CNHK500对乳腺癌的特异性杀伤作用.方法: 行病毒增殖实验和细胞生长抑制实验,验证CNHK500选择性复制和杀伤能力; Western blot检测腺病毒E1A和E1B在细胞中的表达.结果: CNHK500在乳腺癌细胞中复制能力与野生型腺病毒wtAd5相似,较ONYX-015增殖能力强.在正常成纤维细胞中CNHK500病毒增殖能力明显减弱, 较wtAd5增殖能力弱1 000倍左右.CNHK500可有效杀伤乳腺癌细胞株;而CNHK500对正常成纤维细胞的杀伤力较wtAd5减弱约100倍.CNHK500病毒的E1A可以选择性在端粒酶阳性的乳腺癌细胞株中表达,在端粒酶阴性的正常成纤维细胞株BJ中不表达, CNHK500可以选择性地在缺氧条件下表达E1B.动物实验结果显示,静脉注射CNHK500可以显著抑制MCF-7乳腺癌细胞裸鼠移植瘤的生长,治疗效果与给药剂量相关.结论: 肿瘤选择性增殖腺病毒CNHK500可选择性在端粒酶阳性的乳腺癌细胞中复制,并产生体内外杀伤作用.