A simplified one-pot synthesis of 9-[(3-[18F]fluoro-1-hydroxy-2-propoxy)methyl]guanine([18F]FHPG) and 9-(4-[18F]fluoro-3-hydroxymethylbutyl)guanine ([18F]FHBG) for gene therapy

9-[(3-[18F]Fluoro-1-hydroxy-2-propoxy)methyl]guanine ([18F]FHPG, 2) has been synthesized by nucleophilic substitution of N(2)-(p-anisyldiphenylmethyl)-9-[[1-(p-anisyldiphenylmethoxy)-3-toluenesulfonyloxy-2-propoxy]methyl]guanine (1) with potassium [18F]fluoride/Kryptofix 2.2.2 followed by deprotection with 1 N HCl and purification with different methods in variable yields. When both the nucleophilic substitution and deprotection were carried out at 90 degrees C and the product was purified by HPLC (method A), the yield of compound 2 was 5-10% and the synthesis time was 90 min from EOB. However, if both the nucleophilic substitution and deprotection were carried out at 120 degrees C and the product was purified by HPLC, the yield of compound 2 decreased to 2%. When compound 2 was synthesized at 90 degrees C and purified by Silica Sep-Pak (method B), the yield increased to 10-15% and the synthesis time was 60 min from EOB. Similarly, 9-(4-[18F]fluoro-3-hydroxymethylbutyl)guanine ([18F]FHBG, 4) was synthesized with method A and method B in 9% and 10-15% yield, respectively, in a synthesis time of 90 and 60 min, respectively, from EOB. Compound 2 was relatively unstable in acidic medium at 120 degrees C while compound 4 was stable under the same condition. Both compound 2 and compound 4 had low lipid/water partition coefficient (0.126 +/- 0.022, n=5 and 0.165 +/- 0.023, n=5, respectively). Although it contains non-radioactive ganciclovir ( approximately 5-30 microg) as a chemical by-product, compound 2 synthesized by method B has a similar uptake in 9L glioma cells as that synthesized by method A, and is a potential tracer for imaging herpes simplex virus thymidine kinase gene expression in tumors using PET. Similarly, compound 4 synthesized by method B contains approximately 10-25 microg of penciclovir as a chemical by-product. Thus, the simplified one pot synthesis (method B) is a useful method for synthesizing both compound 2 and compound 4 in good yield for routine clinical use, and the method is readily amenable for automation.

Gene therapy for high grade gliomas

High grade gliomas in adults are devastating diseases, with very poor survival despite their lack of distant metastases. Local treatments, such as surgical resection and stereotactic radiosurgery, have been most successful, whereas systemic therapy (for example, chemotherapy and immunotherapy) have been rather disappointing. Several gene therapy systems have been successful in controlling or eradicating these tumours in animal models and are now being tested as a logical addition to current clinical management. This review describes the gene therapy clinical protocols that have been completed or that are ongoing for human gliomas. These include the prodrug activating system, herpes simplex thymidine kinase (HSVtk)/ganciclovir (GCV), utilising either retrovirus vector producer cells or adenovirus vectors; adenovirus mediated p53 gene transfer; adenovirus mediated IFN-beta gene transfer and oncolytic herpes virus and adenovirus vectors. To date, all of the clinical studies have used direct injection of the vector into the glioma. The Phase I clinical studies have demonstrated low to moderate toxicity and variable levels of gene transfer and in some cases anti-tumour effect. Future directions will rely upon improvements in gene delivery as well as gene therapies and combinations of gene therapy with other treatment modalities.

Importance of dose intensity in neuro-oncology clinical trials: summary report of the Sixth Annual Meeting of the Blood-Brain Barrier Disruption Consortium

Therapeutic options for the treatment of malignant brain tumors have been limited, in part, because of the presence of the blood-brain barrier. For this reason, the Sixth Annual Meeting of the Blood-Brain Barrier Disruption Consortium, the focus of which was the "Importance of Dose Intensity in Neuro-Oncology Clinical Trials," was convened in April 2000, at Government Camp, Mount Hood, Oregon. This meeting, which was supported by the National Cancer Institute, the National Institute of Neurological Disorders and Stroke, and the National Institute of Deafness and Other Communication Disorders, brought together clinicians and basic scientists from across the U.S. to discuss the role of dose intensity and enhanced chemotherapy delivery in the treatment of malignant brain tumors and to design multicenter clinical trials. Optimizing chemotherapy delivery to the CNS is crucial, particularly in view of recent progress identifying certain brain tumors as chemosensitive. The discovery that specific constellations of genetic alterations can predict which tumors are chemoresponsive, and can therefore more accurately predict prognosis, has important implications for delivery of intensive, effective chemotherapy regimens with acceptable toxicities. This report summarizes the discussions, future directions, and key questions regarding dose-intensive treatment of primary CNS lymphoma, CNS relapse of systemic non-Hodgkin's lymphoma, anaplastic oligodendroglioma, high-grade glioma, and metastatic cancer of the brain. The promising role of cytoenhancers and chemoprotectants as part of dose-intensive regimens for chemosensitive brain tumors and development of improved gene therapies for malignant gliomas are discussed.

Imaging in vivo herpes simplex virus thymidine kinase gene transfer to tumour-bearing rodents using positron emission tomography and

Radiolabelled ganciclovir analogues have shown promise as imaging agents to detect herpes simplex virus thymidine kinase (HSVtk) expression. This study evaluated the use of positron emission tomography (PET) imaging with 9-[(3-[18F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([18F]FHPG) to assess gene transfer into tumours. HSVtk-positive and HSVtk-negative cell lines were first treated in vitro with [18F]FHPG. To assess the efficacy of PET in detecting HSVtk expression following in vivo gene transfer, mice were injected intravenously with an adenovirus encoding HSVtk (Ad.HSVtk), a control vector (Ad.Bgl2) or saline. Subcutaneous human glioma xenografts were grown in mice and treated by direct injection of Ad.HSVtk or Ad.Bgl2. Imaging was performed 48 h after transduction. Similar experiments were performed using Fischer rats implanted with syngeneic tumours. The presence of the HSVtk protein was confirmed by immunohistochemistry. Biodistribution studies were also obtained in 14 naive mice. In vitro studies showed high and specific uptake of [18F]FHPG in HSVtk-positive cell lines, with an uptake ratio of up to 27:1. PET imaging and direct counting of major organs demonstrated HSVtk-specific tracer retention. In mice, HSVtk-positive tumours retained 3.4% dose/gram as compared to 0.6% for control tumours (P=0.03). They were clearly seen on the PET images as early as 100 min post injection. Similar results were obtained with syngeneic rat tumours. Biodistribution studies demonstrated the rapid distribution and clearance of the tracer in all major organs. Our results demonstrate that PET imaging of HSVtk gene transfer to tumours is feasible and is highly specific for HSVtk expression.

An intra-Peyer's patch gene transfer model for studying mucosal tolerance: distinct roles of B7 and IL-12 in mucosal T cell tolerance

Development of mucosal immunity and tolerance requires coordinated expression of a number of genes within the mucosa-associated lymphoid tissue (MALT). To study the roles of these genes in the MALT, we have established a MALT-specific gene transfer model using replication-defective adenovirus as vector. In this model, the target gene of interest is directly delivered into the Peyer's patch by intra-Peyer's patch injection of the recombinant virus. Using this gene transfer model, we investigated the roles of B7-1 and IL-12 in the development of mucosal tolerance. We found that intra-Peyer's patch injection of OVA induced Ag-specific T cell hyporesponsiveness, as manifested by decreased T cell proliferation and IL-2/IFN-gamma production upon subsequent immune challenge. Intra-Peyer's patch B7-1 gene transfer at the time of OVA administration partially reversed the inhibition of T cell proliferation and IL-2 secretion, but had no effect on IFN-gamma production. By contrast, intra-Peyer's patch IL-12 gene transfer completely restored T cell proliferation and IFN-gamma secretion and partially reversed IL-2 inhibition. Using an adoptive TCR transgenic model, we further demonstrated that B7 and IL-12 played distinct roles during the inductive phase of mucosal tolerance. B7 selectively increased T cell proliferation and IL-2 secretion without affecting IFN-gamma production, whereas IL-12 increased both IL-2 and IFN-gamma production. These results indicate that B7 alone may not be sufficient to abrogate mucosal tolerance, and that cytokines such as IL-12 may also be required. Based on these findings, we propose a new model to explain the paradoxical roles of B7 in mucosal immunity and tolerance.

Basic fibroblast growth factor induces a transformed phenotype in normal human melanocytes

Basic fibroblast growth factor (bFGF or FGF-2) is produced by nearly all melanomas in vitro and in vivo but not by normal melanocytes, which require exogenous bFGF for growth. In this study, we transduced normal human melanocytes to overexpress two forms of bFGF: (bFGF-Long and bFGF-Short) using replication-deficient adenovirus 5 vectors. bFGF-Long induced the 17.8, 22.5, 23.1 and 24.2 kDa forms of bFGF, whereas bFGF-Short induced only the 17.8 kDa mature form. Growth of cultured melanocytes transduced with either vector was similar to that of nevus and melanoma cells and was independent of exogenous bFGF and of insulin/insulin-like growth factor 1, and cyclic AMP enhancers, requiring only phorbol ester as an exogenous mitogen. Like primary melanoma cells, transduced normal melanocytes grew anchorage independently in soft agar. When injected into the dermis of human skin grafted to mice, bFGF-transduced melanocytes proliferated for at least 20 days, whereas cells from control cultures showed poor survival and no proliferation. These results demonstrate that bFGF upregulation is a critical component in melanoma progression.

Molecular characterization of an adenoviral vector resulting from both homologous and nonhomologous recombination

Recombinant adenoviral vectors are being used extensively for gene transfer. During the construction of an E1-deleted virus expressing the human B7-1 gene, an aberrant recombinant (Ad.ihB7-1) arose with an unusual 5' sequence. Characterization and sequencing of Ad.ihB7-1 showed that its structure was the result of both homologous and nonhomologous events. The most striking features of the construct were the incorporation of bacterial genomic DNA, an additional inverted terminal repeat, and portions of E1a. The appearance of this construct has implications for vector design and indicates the need for careful analysis and characterization of recombinant adenoviral vectors for clinical use.

Adenoviral transduction of melanoma cells with B7-1: antitumor immunity and immunosuppressive factors

Previous studies in experimental models have demonstrated that the transduction of human or murine melanoma cells with the co-stimulatory B7-1 molecule induces effective antitumor immune responses. In order to develop B7-1 gene transfer as a therapeutic tool in the clinical management of melanoma, efficient means of in vivo gene transfer must be used. To this end we evaluated in vitro and in vivo immune responses associated with adenoviral transduction of murine and human melanoma cells with B7-1. Adenovirus-mediated transduction of human and murine melanoma cells with B7-1 leads to high-level transgene expression in vitro and in vivo and does not affect MHC class I and II expression. Adenovirus-delivered B7-1 induced antitumor immune responses, on the basis of observations that human melanoma cells transduced to express human B7-1 were able to co-stimulate allogeneic and autologous T cells to proliferate and that murine melanoma K1735 cells transduced to express murine B7-1 were rejected by syngeneic, immunocompetent mice. By contrast, intratumoral injection of an adenovirus encoding murine B7-1 failed to eliminate established murine melanoma (K1735) despite high-level transgene expression in tumor cells. Potent T cell inhibitory factor(s) secreted by both K1735 cells and select human melanoma cells may contribute to the failure to achieve protection in this setting. Thus, immune inhibitory melanoma-derived factors need to be taken into account when considering the clinical use of B7-1 immunotherapy.

Gene therapy for breast cancer

Gene therapy for breast cancer is still in the very early stages of development. Many of the molecular strategies that have been proposed are also being developed for other cancers. Their application to breast cancer, however, needs to address several issues specific to this disease such as the widespread nature of metastases, the indolent growth of the tumor cells, and the production by the tumor of immunosuppressive agents. Nonetheless, these approaches appear promising, particularly those that employ a combination of strategies. Gene therapies that affect the biology of breast cancer cells or regulate host immune mechanisms have been most successful and may be paired with existing therapies for breast cancer.

Gene therapy for malignant gliomas

Malignant gliomas are attractive targets for gene therapy because of their relatively well-localized distribution. Several new strategies have been devised that target different aspects of glioma biology. Gene transfer can be used to synthesize chemotherapy drugs that block DNA synthesis within these highly mitotic tumors. New genes can be introduced that restore the functions of mutated tumor suppressor genes or block the molecular pathways needed for tumor angiogenesis. Alternatively, the immune response to these tumors can be augmented by the local production of cytokines. Finally, viruses themselves can be used as tumoricidal agents by designing viruses that selectively replicate and destroy tumor cells. The advantages and limitations of these approaches are discussed in the context of their possible application to the treatment of these highly lethal malignancies.

Future directions for the treatment of colorectal carcinoma

Most of these therapies, although still in the infant stages of their development, offer the potential for major advances in colorectal cancer therapy. Gene therapy is an entirely new medicinal paradigm for the treatment of cancer. Currently, the clinical application of these methods is limited by the need for a more through understanding of cancer immunology and the availability of better vector systems for efficient and selective tumor gene transfer. As increasing numbers of scientists and clinicians address these issues, better therapies will likely emerge.

High-efficiency stable gene transfer of adenovirus into mammalian cells using ionizing radiation

We report a novel method for targeting adenovirus-mediated gene delivery. By irradiating mammalian cells prior to adenoviral transduction, adenoviral gene transfer is greatly improved and the adenoviral genome integrates into cellular DNA. In this work, human and rodent cell lines were irradiated and subsequently transduced with the adenovirus vector Ad5CMVlacZ. Initial levels of transduction were as much as 40-fold higher in irradiated cells, and this improvement in transduction was radiation dose dependent. The duration of lacZ expression in irradiated cells was also much longer than in nonirradiated cells and reached a plateau after 21 days. At doses of 7 Gy, long-term (< 50 day) expression of lacZ could be detected in 15% of cells by flow cytometry. This long-lasting expression of lacZ was due to viral DNA integration into the host genome. Thus, pretreatment of cells with ionizing radiation improves both immediate transduction efficiency and duration of transgene expression. This may lead to the development of new protocols combining radiation and gene therapy in treating human malignancy.

Intracranial administration of adenovirus expressing HSV-TK in combination with ganciclovir produces a dose-dependent, self-limiting inflammatory response

Replication-defective adenovirus expressing the herpes simplex thymidine kinase gene (H5.010RSVtk) may be useful in treating human gliomas. To determine the toxicity of this therapeutic strategy, we injected H5.010RSVtk stereotactically into the normal brain of Wistar rats, cotton rats, and rhesus monkeys in conjunction with systemic ganciclovir (GCV) at 10 mg/kg per day. In the Wistar rat, 5.7 x 10(9) pfu resulted in histopathologic injury consisting of localized necrosis, mild gliosis, marked malacia, and focal astrocytosis; however, 1.0 x 10(8) pfu resulted in only mild gliosis and trace meningitis and approximates a "no toxic effect" dose. A dose of 1.0 x 10(9) pfu in both adenoviral immune and adenoviral naive cotton rats resulted in similar findings. In the rhesus monkey, doses ranging from 1.4 x 10(8) pfu to 1.5 x 10(11) pfu resulted in localized gliosis, necrosis, perivascular cuffing, meningitis, and roughly correlated in severity with increasing dose. No histologic evidence of toxicity was found in non-central nervous system (CNS) tissues, and no virus could be cultured from cerebrospinal fluid (CSF), blood, urine, and stool samples. All animals survived to prescribed end points without signs of general toxicity or neurologic symptoms, except for 2 of the rhesus monkeys, one of which became febrile and the other of which developed a grand mal seizure (both subsequently resolved). These toxicology studies define the parameters for developing a phase I clinical trial.

Adenovirus-mediated gene therapy of ovarian cancer in a mouse model

OBJECTIVE

Our purpose was to test the feasibility of adenovirus-mediated gene therapy of ovarian cancer.

STUDY DESIGN

Ovarian cancer cell lines were exposed to an adenovirus vector expressing a reporter gene (lacZ) and to the same vector bearing the herpes simplex virus thymidine kinase gene (Ad.RSVtk) followed by ganciclovir. lacZ expression and growth inhibition were quantitated. Immunodeficient mice were injected intraperitoneally and subcutaneously with human ovarian cancer cells and treated with Ad.RSVtk and ganciclovir. Statistical analyses included one-way analysis of variance and t tests.

RESULTS

Staining for lacZ demonstrated viral transduction in vitro. After exposure to Ad.RSVtk all cell lines showed significant (p < 0.0001, analysis of variance) cytotoxicity to ganciclovir. Human ovarian tumor cells established subcutaneously or intraperitoneally in immunodeficient mice responded to therapy with Ad.RSVtk followed by ganciclovir. Treated mice had a 10- to 20-fold lower subcutaneous tumor burden than did control mice. Additionally, no intraperitoneal tumors were observed in treated mice.

CONCLUSIONS

Ovarian cancer cells are readily transduced with recombinant adenovirus and become sensitive to ganciclovir after transduction with Ad.RSVtk. These data support the development of this method for human clinical trials.

Treatment of advanced CNS malignancies with the recombinant adenovirus H5.010RSVTK: a phase I trial

Primary CNS malignancies are responsible for approximately 12,000 deaths annually in the United States. There has been little change in the outcome for adults with malignant brain tumors over the past few decades, despite improvements in surgical techniques and advances in radiation therapy. These tumors are uniformly fatal one to two years after diagnosis. The morbidity and mortality of this disease arise from the effects of a locally invasive, non-metastasizing lesion. The patients may suffer from seizures, paralysis, incoordination, aphasia, confusion, memory loss, sensory deficits or visual loss, depending on the regions of the brain affected. In addition, they usually require large doses of corticosteroids early and late in their illness, and may experience disabling side effects of this treatment, such as edema, proximal myopathy, diabetes, fungal infections or deep vein thrombosis. Few patients in the older age group are able to work after the diagnosis. Most of the patients are incapable of self-care for several months before death. The localized transfer of new genes into cancer cells potentially permits the expression of proteins with specific biologic functions that may provide a means to alter the biology of tumor growth through a variety of mechanisms including increasing tumor immunogenicity, inducing the local expression of toxic agents, and sensitization of tumors to chemotherapeutic agents. Gene therapy with the transfer of the drug susceptibility gene Herpes virus thymidine kinase (HSV-TK) has shown promise in a number of animal models, including CNS tumors. This study will evaluate the use of adenovirus-mediated transfer of the HSV-TK gene into primary human brain tumors followed by systemic treatment with ganciclovir. The goals of this phase I study are to evaluate the overall safety and efficacy of this treatment and to gain insight into the parameters that may limit the general applicability of this approach. In this phase I study, patients with recurrent gliomas will receive stereotactic-guided injections of the virus into the brain tumor, followed by intravenous ganciclovir for 14 days. Patients eligible to undergo a palliative debulking procedure will receive the same treatment followed by resection on day 7. At the time of resection a second dose of virus will be administered intra-operatively into the residual, unresectable portion of the tumor, and intravenous ganciclovir will be continued for additional 14 days. Tissue removed at the time of resection will be analyzed for evidence of adenovirus infection, thymidine kinase expression and signs of inflammation. The size and metabolic activity of all tumors will be followed by volumetric MRI scans and Position Emission Tomography Scans, respectively. Patients will be enrolled in groups of three, with each group receiving successively larger doses of adenovirus. This study will quantify the toxicity of this therapy, and provide evidence as to the duration of transgene expression and virus induced inflammation.

B7-1 and interleukin 12 synergistically induce effective antitumor immunity

Enhanced host rejection of tumor cells is the primary goal of cancer immunotherapy and, in many murine tumor models, has been accomplished by engineering cells to express B7 costimulatory molecules or creating an environment rich in certain cytokines. We examined the effect of tumor cell B7-1 expression and administered recombinant interleukin 12 (IL-12) on the syngeneic host response to rapidly growing, poorly immunogenic SCK mammary carcinoma cells and to more slowly growing, immunogenic K1735 melanoma cells. Whereas B7-1 expression induced rejection of K1735 cells in 78% of mice, and IL-12 induced rejection in 38%, B7-1 expression induced rejection of SCK cells in only 28% of mice, and IL-12 induced rejection in none. The relative ineffectiveness of either B7-1 or IL-12 alone to induce rejection of SCK cells led us to combine the two manipulations. This resulted in rejection of SCK cells in 74% of mice and dramatically delayed tumor development in the remainder. Tumor rechallenge studies indicated that the surviving mice developed specific immunity to wild-type SCK cells. Lymphocyte subset ablation and IFN-gamma depletion studies indicated that rejection of SCK tumor cells brought about by the synergistic effects of B7-1 and IL-12 is mediated by a rapidly developing, systemic antitumor immune response that is dependent on the presence of both CD8+ and CD4+ T cells and involves IFN-gamma. Additionally, the synergistic effect of B7-1 expression and IL-12 administration is capable of inducing rejection of control SCK tumors simultaneously established in the opposite flank. The efficacy of B7-1 and IL-12 in inducing protective immunity against a poorly immunogenic, aggressive murine tumor indicates that this combination is particularly effective at producing a potent antitumor immune response that may be of therapeutic benefit.

Treatment of experimental human mesothelioma using adenovirus transfer of the herpes simplex thymidine kinase gene

OBJECTIVE

The authors demonstrate the ability of an adenovirus vector expressing the herpes simplex thymidine kinase (HSVtk) gene to treat human malignant mesothelioma growing within the peritoneal cavity of severe combined immunodeficient (SCID) mice.

BACKGROUND DATA

Introduction of the HSVtk gene into tumor cells renders them sensitive to the antiviral drug ganciclovir (GCV). This approach has been used previously to treat experimental brain tumors. Although malignant mesothelioma is refractory to current therapies, its localized nature and the accessibility of the pleural space make it a potential target for a similar type of in vivo gene therapy using adenovirus.

METHODS

An adenovirus containing the HSVtk gene (Ad.RSVtk) was used to transduce mesothelioma cells in vitro. These cells were then injected into the flanks of SCID mice. Ad.RSVtk was also injected directly into the peritoneal cavity of SCID mice with established human mesothelioma tumors. Mice were subsequently treated for 7 days with GCV at a dose of 5 mg/kg.

RESULTS

Mesothelioma cells transduced in vitro with Ad.RSVtk formed nodules when injected in the subcutaneous tissue. These tumors could be eliminated by the administration of GCV, even when as few as 10% of cells were transduced to express HSVtk (bystander effect). Administration of Ad.RSVtk into the peritoneal space of animals with established multifocal human mesothelioma followed by GCV therapy resulted in the eradication of macroscopic tumor in 90% of animals and microscopic tumor in 80% of animals when evaluated after 30 days. The median survival of animals treated with Ad.RSVtk/GCV was significantly longer than that of control animals treated with similar protocols.

CONCLUSION

These results indicate that an adenoviral vector containing the HSVtk gene is effective in treating established malignant mesothelioma in an in vivo setting and raise the possibility of using adenovirus transfer of HSVtk for clinical trials in mesothelioma and other localized tumors.

Use of recombinant adenovirus to transfer the herpes simplex virus thymidine kinase (HSVtk) gene to thoracic neoplasms: an effective in vitro drug sensitization system

Transfer of the herpes simplex virus thymidine kinase (HSVtk) gene into tumor cells using retroviral vectors followed by administration of ganciclovir provides a potential strategy for the treatment of malignancy. Because of the limitations of using retroviral vectors for clinical application, the feasibility of using a recombinant adenovirus containing HSVtk was examined. Cell lines derived from human malignant mesotheliomas and non-small cell lung cancers infected with a recombinant adenovirus containing HSVtk showed strong expression of HSVtk protein as determined by immunohistochemical staining. Infection with a recombinant adenovirus containing HSVtk rendered cells sensitive to doses of ganciclovir that were 2-3 logs lower than uninfected cells or those infected with a control virus. A strong "bystander effect" was noted in mesothelioma lines; there was no diminution in the efficacy of ganciclovir treatment until the ratio of infected:uninfected cells fell below 1:10. This study thus demonstrates in vitro efficacy of an adenovirus-transduced HSVtk drug sensitization gene therapy system in thoracic malignancies. Recombinant adenovirus transfer of the HSVtk gene followed by ganciclovir may have promise as an in situ treatment for tumors.

Inhibition of phorbol ester-induced cellular adhesion by competitive binding of NF-kappa B in vivo

Adhesive interactions between cells are essential for the organization and function of differentiated tissues and organs and are mediated by inducible cell surface glycoproteins. In normal tissues, cell adhesion molecules contribute to immune regulation, inflammation, and embryogenesis. Additionally, they play an important role in a variety of pathogenic processes. Cell adhesion molecule expression can be induced by stimuli known to activate NF-kappa B, a ubiquitous transcription factor found in a variety of cell types. To investigate the role of NF-kappa B in cell adhesion molecule expression, we treated HL-60 cells with a double-stranded oligonucleotide which specifically inhibits NF-kappa B-mediated transcription. This treatment resulted in the inhibition of phorbol 12-myristate 13-acetate (PMA)-induced cellular adhesion, morphological changes, and the expression of leukocyte integrin CD11b. In a similar fashion, expression of intercellular adhesion molecule 1 on human endothelial cells induced by PMA was specifically inhibited by the NF-kappa B antagonist. We suggest that NF-kappa B activation is a necessary event for the PMA-induced differentiation of HL-60 cells and the expression of certain activation is a necessary event for the PMA-induced differentiation of HL-60 cells and the expression of certain adhesion molecules. Furthermore, the inhibition of transcription factor functions by this generally applicable mechanism can be used to define their role in cellular differentiation and function.

Angioedema presenting as chronic gastrointestinal symptoms

Gastrointestinal complaints may be the presenting feature of patients with acquired or hereditary angioedema. We describe two patients with episodic nausea, abdominal pain, and cramping secondary to C1 inhibitor deficiency. In one patient, an acquired deficiency arose as a paraneoplastic syndrome with abdominal complaints preceding the diagnosis of an occult lymphoma. The second patient presented at age 61 with abdominal complaints secondary to a hereditary deficiency of C1 inhibitor. The patients' symptoms were due to gastrointestinal angioedema, resulting from episodic unregulated complement activation. The biochemical mechanism of this unusual syndrome and its diagnostic importance are discussed. A C1 inhibitor deficiency should be considered in patients with unexplained abdominal symptoms suggestive of intestinal pseudo-obstruction.

Evaluation and treatment of acute myocardial infarction complicating systemic lupus erythematosus

Coronary artery disease has emerged as an important cause of death in young patients with SLE. We report three cases of acute myocardial infarction in young lupus patients who underwent emergent coronary angiography. One patient had a large coronary aneurysm and died five months later from myocarditis. The other two patients underwent coronary angioplasty. The difficulty in distinguishing coronary arteritis from premature atherosclerosis and its relevance to methods of treatment is discussed.

Antisense oligonucleotides for therapeutic intervention

Advances have been made in defining the best target sequences for use in antisense oligonucleotide technology, and new chemical derivatives of oligonucleotides are being investigated. Although the potential use of antisense oligonucleotide agents in the treatment of neoplastic, viral and parasitic diseases continues to be explored, they are not yet suitable for administration to humans for reasons that are discussed.