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Hidde J Haisma

Publications and source records attributed to Hidde J Haisma.

28 records · Page 2Linked to original sources
PubMed2003

Resistance of rat hepatocytes against bile acid-induced apoptosis in cholestatic liver injury is due to nuclear factor-kappa B activation.

BACKGROUND/AIMS: To examine the extent and mechanisms of apoptosis in cholestatic liver injury and to explore the role of the transcription factor nuclear factor-kappa B in protection against bile acid-induced apoptosis. METHODS: Cholestatic liver injury was induced by bile duct ligation in Wistar rats. Furthermore, primary cultures of rat hepatocytes were exposed to glycochenodeoxycholic acid (GCDCA), tauroursodeoxycholic acid (TUDCA), taurochenodeoxycholic acid (TCDCA) and to cytokines. Apoptosis was determined by TUNEL-staining, active caspase-3 staining, activation of caspase-8, -9 and -3. RESULTS: Limited hepatocyte apoptosis and an increased expression of NF-kappaB-regulated anti-apoptotic genes A1 and cIAP2 were detected in cholestatic rat livers. Bcl-2 expression was restricted to bile duct epithelium. In contrast to TCDCA and TUDCA, GCDCA induced apoptosis in a Fas-associated protein with death domain (FADD)-independent pathway in hepatocytes. Although bile acids do not activate NF-kappaB, NF-kappaB activation by cytokines (induced during cholestasis) protected against GCDCA-induced apoptosis in vitro by upregulating A1 and cIAP2. CONCLUSIONS: GCDCA induces apoptosis in a mitochondria-controlled pathway in which caspase-8 is activated in a FADD-independent manner. However, bile acid-induced apoptosis in cholestasis is limited. This could be explained by cytokine-induced activation of NF-kappaB-regulated anti-apoptotic genes like A1 and cIAP2.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Liposome-mediated targeting of enzymes to cancer cells for site-specific activation of prodrugs: comparison with the corresponding antibody-enzyme conjugate.

PURPOSE: Immunoenzymosomes are tumor-targeted immunoliposomes bearing enzymes on their surface. These enzymes are capable of converting relatively nontoxic prodrugs into active cytostatic agents. The aims of this study were to compare the enzyme delivery capability of immunoenzymosomes with that of the corresponding antibody-enzyme conjugate and to evaluate whether immunoenzymosomes are able to mount a strong bystander effect. METHODS: Immunoenzymosomes exposing Fab' fragments of the monoclonal antibody 323/A3 and the bacterial enzyme beta-glucuronidase or the corresponding antibody-enzyme conjugate were incubated with OVCAR-3 cells (human ovarian carcinoma cells). Cell-associated enzymatic activity and the in vitro antiproliferative effect of a glucuronide prodrug of doxorubicin (DOX-GA3) were determined. RESULTS: At equal numbers of carrier units, the cell-associated enzymatic activity achieved by using immunoenzymosomes was 15-fold higher than that obtained after incubation with the corresponding antibody-enzyme conjugate. Increasing the amount of antibody-enzyme conjugate added to the cells could not compensate for their lower enzyme delivery capability. Immunoenzymosomes were able to induce inhibition of cell growth not only of tumor cells to which immunoenzymosomes were bound but also of a large number of neighboring cells. CONCLUSIONS: Immunoenzymosomes are able (a) to target prodrug-converting enzymes more efficiently to tumor cells than the corresponding antibody-enzyme conjugate and (b) to mount a strong bystander effect.

Animals↗
PubMed2003

The recombinant anti-EGF receptor immunotoxin 425(scFv)-ETA' suppresses growth of a highly metastatic pancreatic carcinoma cell line.

Pancreatic carcinoma still has the highest mortality rate in comparison to any other malignancy. Major reasons are late detection of disease, highly aggressive tumor growth and the early formation of metastases. Thus, novel effective therapies are urgently needed to improve the outcome of the patients. Overexpression of the epidermal growth factor receptor (EGFR) and its ligands has been implicated in the oncogenesis of pancreatic carcinoma and associated with an unfavorable prognosis. Consequently, the EGFR represents a specific target antigen suitable for immunotherapy. We generated a recombinant immunotoxin by fusing the anti-EGFR single chain fragment 425(scFv) to a truncated mutant of Pseudomonas Exotoxin A (ETA'). Using the expression vector pBM1.1, functional 425(scFv)-ETA' was periplasmically expressed under osmotic stress conditions in the presence of compatible solutes. The 72 kDa His10-tagged fusion protein was purified by a combination of metal-ion affinity and molecular size chromatography. Binding activity and specificity of the immunotoxin to the EGFR-positive pancreatic carcinoma cell line L3.6pl was confirmed by flow cytometry and ELISA. Finally, 425(scFv)-ETA' showed significant toxicity toward this cell line reaching 50% inhibition of cell proliferation at a concentration (IC50) of 7.5 ng/ml. This is the first report documenting the specific cytotoxicity of a recombinant immunotoxin towards metastatic pancreatic carcinoma cells, suggesting that EGFR-specific antibody toxins may become valuable therapeutic reagents for the treatment of pancreatic carcinoma.

Carcinoma↗
PubMed2003

Intravenous delivery of adenovirus-mediated soluble FLT-1 results in liver toxicity.

PURPOSE: Vascular endothelial growth factor (VEGF) is a potent angiogenic agent and plays a major role in tumor growth and metastases. We have previously reported the locoregional (i.p.) delivery of adenovirus-mediated antiangiogenic soluble FLT-1 (sFLT-1; a naturally encoded potent VEGF antagonist) gene therapy to inhibit VEGF action in a murine ovarian carcinoma model. This study was predicated on the fact that systemic delivery of sFLT-1 might allow an approach for therapy of disseminated tumor. The purpose of this study is to test the effects of i.v. delivered, adenovirus-mediated sFLT-1 on the survival duration in a murine ovarian tumor model and to evaluate the safety of i.v.-delivered versus i.p.-delivered adenovirus-mediated sFLT-1 in non-tumor-bearing mice. EXPERIMENTAL DESIGN: To determine the effects of i.v.-administered adenovirus-mediated sFLT-1 on survival duration of mice bearing i.p. human ovarian tumors, an E1A/B-deleted, (replication-deficient) infectivity-enhanced recombinant adenovirus AdRGDGFPsFLT-1 encoding cDNA for both sFLT-1 and GFP (green fluorescent protein), a control adenovirus AdRGDGFP encoding GFP alone, or PBS was delivered i.v. The therapeutic effect of sFLT-1 was evaluated by survival duration of the mice. Furthermore, the safety of i.v.- or i.p.-delivered adenovirus-mediated sFLT-1 was evaluated by administering AdRGDGFPsFLT-1, AdRGDGFP, or PBS either i.v. or i.p. into non-tumor-bearing mice. Adenovirus-mediated gene expression was determined by determining GFP expression using fluorescent microscopy and by assessing sFLT-1 expression in liver, lungs, spleen, and kidneys by immunohistochemistry using anti-FLT-1 monoclonal antibody. Systemic levels of sFLT-1 were evaluated by ELISA and the toxicity was evaluated by histopathology. RESULTS: The i.v. delivery of AdRGDGFPsFLT-1 in the ovarian tumor model resulted in a shorter duration of survival of the mice as compared with the control group. Furthermore, in the safety evaluation experiment, i.v. administration of AdRGDGFPsFLT-1 in non-tumor-bearing mice principally localized to the liver. This localization lead to sFLT-1 overexpression, mainly in the liver, resulting in hemorrhage and tissue toxicity. However, i.p. delivery of AdRGDGFPsFLT-1 did not localize principally to the liver, leading to negligible expression of sFLT-1, and no intrahepatic hemorrhage or toxicity was observed. The i.v. delivery of the control virus AdRGDGFP also principally localized to the liver, leading to GFP expression mainly in the liver. However, neither hemorrhage nor morphological cytotoxicity was observed. i.p. delivery of AdRGDGFP resulted in ectopic localization to the liver with very little GFP expression and no toxicity. These results suggest that overexpression of sFLT-1 in the liver as a result of i.v. delivery is hepatotoxic. CONCLUSIONS: Our results suggest that i.v. delivery of the sFLT-1 gene via replication-deficient, infectivity-enhanced recombinant adenoviral vectors will result in overexpression of sFLT-1 in the liver leading to unacceptable hepatotoxicity. Tumor-specific targeting of the vectors and tumor-specific expression strategies should be used to ensure a clinically useful antiangiogenesis gene therapy.

Adenoviridae↗
PubMed2003

Gene-directed enzyme prodrug therapy for osteosarcoma: sensitization to CPT-11 in vitro and in vivo by adenoviral delivery of a gene encoding secreted carboxylesterase-2.

Despite improvement in the treatment of osteosarcoma (OS), there are still many patients who cannot benefit from current treatment modalities. This warrants exploration of new treatment options. To that end, we investigated gene-directed enzyme prodrug therapy (GDEPT) with the use of human liver carboxylesterase-2 (CE2) and the anticancer agent CPT-11. CPT-11 is a clinically approved prodrug that needs to be metabolized into the active drug SN-38 by CEs, which occurs rather inefficiently in humans. GDEPT aims at high production of CE2 at the tumor site, resulting in efficient local conversion of CPT-11 into SN-38. Here, we show that OS cells transduced with an adenoviral vector containing the cDNA encoding a secreted form of CE2 (Ad-sCE2) expressed and efficiently secreted CE2. In vitro, transduction of a panel of OS cell lines with Ad-sCE2 resulted in sensitization up to 2800-fold to CPT-11 treatment. Primary OS short-term cultures, derived from patients suffering from a classic high-grade OS, demonstrated increased CPT-11 sensitivity up to 70-fold after transduction with Ad-sCE2 in vitro. When mice bearing s.c. MG-63 OS xenografts were intratumorally injected with Ad-sCE2 and CPT-11, this resulted in a significant difference in time to reach 2000 mm(3) in tumor volume as compared with animals receiving Ad-sCE2 or CPT-11 treatment (P < 0.05). Taken together, these data suggest that OS cells are sensitive for the combination of Ad-sCE2 and CPT-11.

Adenoviridae↗
PubMed2002

Prolonged maturation and enhanced transduction of dendritic cells migrated from human skin explants after in situ delivery of CD40-targeted adenoviral vectors.

Therapeutic tumor vaccination with viral vectors or naked DNA, carrying the genetic code for tumor-associated Ags, critically depends on the in vivo transduction of dendritic cells (DC). Transfection of predominantly nonprofessional APC and only small numbers of DC may hamper proper T cell activation. Aim of this study was, therefore, the targeted, selective, and enhanced in situ transduction of DC. A human skin explant model was used to explore targeted transduction of cutaneous DC after intradermal injection of a bispecific Ab conjugate to link adenoviral (Ad) vectors directly to CD40 on the DC surface. A significantly enhanced transduction efficiency and selectivity, and an increased activation state of migrating DC were thus achieved. Moreover, DC transduced by CD40-targeted Ad maintained their Ag-specific CTL-stimulatory ability for up to 1 wk after the start of migration, in contrast to DC transduced by untargeted Ad, which had lost this capacity by that time. Because DC targeting in vivo might obviate the need for the in vitro culture of autologous DC for adoptive transfer, CD40-targeted Ad vectors constitute a promising new vaccine modality for tumor immunotherapy.

Adenoviruses, Human↗
PubMed2002

Efficient and selective gene transfer into primary human brain tumors by using single-chain antibody-targeted adenoviral vectors with native tropism abolished.

The application of adenoviral vectors in cancer gene therapy is hampered by low receptor expression on tumor cells and high receptor expression on normal epithelial cells. Targeting adenoviral vectors toward tumor cells may improve cancer gene therapy procedures by providing augmented tumor transduction and decreased toxicity to normal tissues. Targeting requires both the complete abolition of native tropism and the addition of a new specific binding ligand onto the viral capsid. Here we accomplished this by using doubly ablated adenoviral vectors, lacking coxsackievirus-adenovirus receptor and alpha(v) integrin binding capacities, together with bispecific single-chain antibodies targeted toward human epidermal growth factor receptor (EGFR) or the epithelial cell adhesion molecule. These vectors efficiently and selectively targeted both alternative receptors on the surface of human cancer cells. Targeted doubly ablated adenoviral vectors were also very efficient and specific with primary human tumor specimens. With primary glioma cell cultures, EGFR targeting augmented the median gene transfer efficiency of doubly ablated adenoviral vectors 123-fold. Moreover, EGFR-targeted doubly ablated vectors were selective for human brain tumors versus the surrounding normal brain tissue. They transduced organotypic glioma and meningioma spheroids with efficiencies similar to those of native adenoviral vectors, while exhibiting greater-than-10-fold-reduced background levels on normal brain explants from the same patients. As a result, EGFR-targeted doubly ablated adenoviral vectors had a 5- to 38-fold-improved tumor-to-normal brain targeting index compared to native vectors. Hence, single-chain targeted doubly ablated adenoviral vectors are promising tools for cancer gene therapy. They should provide an improved therapeutic index with efficient tumor transduction and effective protection of normal tissue.

Adenoviridae↗
PubMed2002

Beta-glucuronidase-mediated drug release.

The selective activation of a relatively non-toxic prodrug by an enzyme present only in the tumour should enhance the drug concentration at the tumour site and result in a better anti-tumour effect and a reduction in systemic toxicity as compared to conventional chemotherapy. beta-Glucuronidase is such an enzyme. It is normally expressed in the lysosomes of cells. In larger tumours, however, high levels of the enzyme are present in necrotic areas. Several glucuronide prodrugs have been synthesised that can be activated by beta-glucuronidase. They are relatively non-toxic due to their hydrophilic nature, which prevents them from entering cells and thus from contact with lysosomal beta-glucuronidase. The main problem of glucuronide prodrugs for clinical use is their fast renal clearance. Special attention should be paid to the development of new less hydrophilic prodrugs with slower clearance, as this would result in a prolonged exposure to beta-glucuronidase at the site of the tumour and a reduction of the amount of prodrug needed. A number of interesting anthracyclin-based glucuronide prodrugs have been synthesised and have shown favourable therapeutic effects compared to treatment with the parent drug. The tumoural levels of beta-glucuronidase can even be enhanced by two-step approaches, in which exogenous enzyme is targeted to the tumour by an antibody (ADEPT) or by the gene encoding the enzyme in transduced tumour cells (GDEPT). The ADEPT and GDEPT approaches in combination with glucuronide prodrugs have shown enhanced efficacy in experimental tumour models. Further improvement of ADEPT and GDEPT is warranted to optimise the tumour uptake and retention of antibody-enzyme fusion proteins and the efficiency and safety of current gene delivery methods. In conclusion, it is clear that glucuronide prodrugs hold promise for future use in the treatment of cancer in patients as monotherapy. Enhancement of the therapeutic effects of glucuronide prodrugs, also in patients with small tumour lesions, may possibly be achieved by techniques that target beta-glucuronidase specifically to the site of the tumour.

Animals↗
PubMed2002

Gene therapy for meningioma: improved gene delivery with targeted adenoviruses.

OBJECT: Due to their surgical inaccessibility or aggressive behavior, some meningiomas cannot be cured with current treatment strategies. Gene therapy is an emerging strategy for the treatment of brain tumors, which the authors investigated to determine whether adenoviruses could be used for gene transfer in meningioma cells. METHODS: The presence of the high-affinity Coxsackievirus and adenovirus receptor (CAR) for adenovirus type 5, as well as endothelial growth factor receptor (EGFR) and alpha, integrins (ITGAVs), were analyzed in primary tumors by using immunohistochemical studies and in primary meningioma cell cultures by using fluorescence-activated cell sorting. Targeting of adenoviruses to EGFR was achieved using bispecific antibodies, whereas targeting of adenoviruses to the ITGAVs was accomplished by insertion of an RGD (arginine-glycine-aspartic acid) motif in the adenovirus fiber H1 loop. Gene transfer efficiency of untargeted and targeted vectors was compared in primary cell cultures and in spheroids derived from patients' resected tumor material. The presence of CARs was observed in all tumors and in all but one of the derived primary meningioma cells. The higher expression of EGFRs and ITGAVs indicated that these receptors could be used as alternative targets to redirect the adenoviruses. Redirection of adenoviruses to the EGFRs or integrins enhanced gene transfer threefold (range two-sevenfold) for EGFRs in primary meningioma cells and ninefold (range three-23-fold) for integrins (p = 0.002, analysis of variance). The effect of adenovirus targeting was confirmed in spheroids composed of primary meningioma cells. CONCLUSIONS: Gene transfer with adenoviruses targeted to tumor-specific receptors is very effective in primary meningioma cells and spheroids. These vectors are promising agents for gene therapy of meningiomas.

Adenoviridae↗