Index

AAV vectors, see Adeno-associated virus vectors ABCG2, hematopoietic stem cell enrichment using drug resistance gene transfer, 265 c-ABL, oncogenes and carcinogenesis, 176, 177 Adeno-associated virus (AAV) vectors, adjuvant therapy in cancer, 150 anti-oncogenic properties, 146 engineering, 145, 146 historical perspective, 142 immunotherapy, 149 long-term expression for cancer therapy, 147, 148 Adenovirus vectors, see also A 24 E1A ONYX-015, clinical trials, ONYX-015, 13, 14 p53 gene delivery,...

Sricharan Chalikonda md and David L Bartlett md

Construction of Recombinant Viral Vectors Strategies in Vaccinia Gene Therapy to Evade Immune Clearance Clinical Safety Vaccinia as a Cancer Vaccine Vaccinia as a Vector for Tumor Directed Gene Delivery Vaccinia as an Oncolytic Virus for Cancer Therapy Summary Vaccinia virus has been studied extensively since its discovery as a smallpox vaccine in 1798. Its use as a smallpox vaccine documented its safety profile. It was later found that its large size and ability to accept large fragments of...

References

A flanking attack on cancer, Nat Med 1998 4 13-14. 2. Pepper MS. Role of the matrix metalloproteinase and plasminogen activator-plasmin systems in angiogenesis, Arterioscler Thromb Vasc Biol 2001 21 1104-1117. 3. Carmeliet P, Jain RK. Angiogenesis in cancer and other diseases, Nature 2000 407 249-257. 4. Folkman J, Klagsbrun M. Angiogenic factors, Science 1987 235 442-447. 5. Ribatti D, Vacca A, Presta M. The discovery of angiogenic factors a historical review, Gen Pharmacol 2000 35...

Introduction

The use of adenoviruses as expression vectors in mammalian cells and in the development of recombinant vaccines dates back to the mid-1980s (1-3). Their use as vectors in gene therapy was inspired by a report in 1990 that in vivo administration of an adenovirus expressing ornithine transcarbamylase corrected inherited defects of this enzyme in mice (4). Since that time, numerous adenovectors expressing a variety of genes for in vivo gene transfer have been reported. Most of these adenovectors...

Host Response To Vaccinia

Vaccinia virus has mechanisms to avoid detection and clearance by the immune system. The vaccinia has evolved expression of immunosuppressive proteins (38). Viral surface proteins act as complement inhibitors and the extracellular envelope is known to be almost completely resistant to antibody neutralization (39). Understanding vaccinia's immune evasion strategies may help optimize the virus as a vector for clinical use. The virus is effective in suppressing both innate immunity and the...

Vsv As A Therapy Against Cancer

Our studies indicate that VSV can infect many types of tumor cells, almost certainly a result of the widely tropic nature of the VSV G protein (21). Whereas the infected tumor cells rapidly die, normal cells are much more resistant to VSV-mediated cytolo-ysis. Importantly, the oncolytic effect of VSV does not appear to be restricted to tumor cells with specific genetic aberrancies. For example, VSV can destroy cells carrying defective Myc or p53, cells with activated Ras, and even cells...

Herpes Simplex Virus Fundamentals Lifelong Latency Punctuated By Episodes Of Productive Growth

O 'er ladies lips, who straight on kisses dream, which oft the angry Mab with blisters plagues, because their breaths with sweetmeats tainted are. - William Shakespeare, Romeo and Juliet, circa 1595. Following infection of oral epithelial cells in its human host, HSV-1 invades axons and travels to the nuclei of sensory neurons that innervate this epithelia. Here, the virus establishes a latent infection, characterized by a restricted pattern of viral gene expression, the assembly of the viral...

Factors Affecting Efficacy Of Ad As An Anticancer Agent

Initial attempts to utilize Ads as anticancer therapeutics were undertaken shortly after their discovery in early 1950s (4). Administration of wild-type Ads into patients with cervical carcinomas did not demonstrate significant efficacy. As a result, further development of Ad-based anticancer therapeutics was essentially abandoned for four decades. By the mid-1990s, accumulated data on the virus genome organization and protein expression coupled with significant insights into mechanisms...

Oncogenes Tumor Suppressor Genes And Apoptosisinducing Genes In Cancer Gene Therapy

Recent advances in molecular biology and biotechnology have led to the development of nucleic acid-based medicines that directly target the genetic alterations or molecular mechanisms required for tumorigenesis or for maintenance of the malignant phenotype. The rationale is that local intratumoral expression of the desired therapeutic proteins may exert a constant therapeutic effect at the cancer site without causing substantial systemic toxicity. A growing body of evidence indicates that...

Challenges And Opportunities In Prostate Cancer

Prostate cancer presents specific opportunities for novel therapies such as cytokine gene therapy but also has specific challenges. Standard therapy for localized disease involves radical prostatectomy or radiation therapy which are often associated with significant morbidity (3). Despite a significant increase in the number of men diagnosed and treated with curative intent for localized prostate cancer, a considerable number of men develop local recurrence or distant disease following surgery...

Adenoassociated Virus For Immunotherapy

The potential of AAV vectors for cancer immunotherapy is evident from recent studies using cytokine gene transfer and in vivo immunization approaches (108-110). Active immunization with tumor cells transduced with rAAV encoding cytokines either by a plasmid based-delivery system or by a recombinant virus-mediated infection has resulted in regression of tumor growth upon further challenge. In a separate study, high-level IFN-y and elevated major histocompatibility complex (MHC) class I...

Genetic Vaccines for Cancer Therapy

A primary focus of current research on genetic vaccination is the development of strategies to activate nonresponsive antigen specific T-cells. The first consideration of any tumor therapy is the choice of cancer antigen in a genetic construct. Much effort has been devoted to the optimization of TAAs, and this work is described in detail elsewhere (11,12). Despite this optimization and the large number of genetic vaccine clinical trials for cancera, DNA vaccination in humans has not elicited as...

Hsv1 Strains

Ground breaking studies by Martuza and colleagues were the first to demonstrate the therapeutic promise of an engineered oncolytic HSV-1 strain, the thymidine kinase (tk) negative HSV-1 mutant, c Zsptk (3). This mutant derivative was chosen because tk mutants replicate effectively in actively dividing cells such as those found in tumors, but are relatively impaired for replication in nondividing cells, such as neurons and therefore display reduced neurovirulence compared with wild-type strains...

Transductional Targeting

One method of adenoviral retargeting employs antibody conjugates whereby an antibody (Ab) component binds to adenovirus and is cross-linking to a targeting moiety facilitating the binding to an alternative receptor (27). An Ab directed against the fiber-knob region has been used because it not only binds to the virus but also eliminates the undesired adenovirus native tropism by masking the region required for CAR affinity. A conjugate consisting of an anti-knob antibody combined with folate...

RNAi In Clinical Cancer Therapy

In concept, diseases such as cancer, which are characterized by overexpression or aberrant activation of specific oncogenes, are suitable candidates for nucleic acid-based gene-silencing therapies. Several nucleic acid drugs that are based on ODNs were under clinical trials and Vitravene (sodium fomivirsen) has been used for the treatment of cytomegalovirus (CMV) infection of the eye in clinics (2,3,5). Several ribozyme-based phase I II clinical trials are in early-phase of clinical evaluation...

VSV Recombinants and Stability

There are no genetic resortment, significant gene loss, integration or transforming properties associated with VSV (25,26). However, polymerase errors can be encountered during the replication of RNA viruses, the result of a lack of robust proofreading capacity (87,100). Neutral mutation frequencies in VSV have been estimated at 1 in 103 to 104 for specific nucleotides in the genome. However, the mutation rate of VSV is so low that it does not present a problem when the virus is used to express...

Interaction of Oncogenes and Tumor Suppressor Genes in Human Carcinogenesis

Humans are the highest class of organism on earth, likewise, human carcinogenesis is more complicated than carcinogenesis in any other organisms. For example, a single activated oncogene can cause neoplastic transformation in avians and rodents. In humans, however, expression of a single oncogene such as myc or ras in normal human cells induces only apoptosis or senescence (31). This has led to the widely accepted concept of multistep carcinogenesis involving the activation of multiple cellular...

Adverse Events During Infusion

The third class of AEs observed initially in the first PV701 trial occurred during infusion, and consisted mainly of back pain, noncardiac chest pressure, and, less commonly, abdominal pain and hypertension. These were particularly noted on repeat dosing at the higher dose levels (particularly > 96 BPFU m2) and were managed effectively by slowing the infusion rate. Indeed, in second PV701 trial (25), this class of AEs became rare when the infusion time beginning for cycle 3 was doubled AEs...

Orthomyxoviruses Influenza Virus

Early recognized oncolytic viruses also included influenza A virus (134). Influenza virus (INV) is a negative-stranded enveloped virus comprising 8 gene segments that replicates in the nucleus of infected cells. Cells are targeted by INV through their surface haemagglutinins (H) attaching to widely expressed sialyloligosaccharide moieties of cellular glycoconjugates. A genetically engineered INV that lacks a nonstructural protein (NS1) that has been reported to inhibit the antiviral protein PKR...

Alphavirus Used In Cancer Vaccines

Alphavirus vectors have frequently been applied for vaccine production. In this context, recombinant particles as well as naked nucleic acids have been applied. The proof of concept was originally demonstrated for viral surface proteins known for their potential immunogenicity and capability to induce cytotoxic T-cell (CTL) responses and protection against challenges with lethal viruses (20). Moreover, immunization against tumor challenges has resulted in some promising observations (Table 1)....

Strategies Using Nonviral Vectors In Cancer Gene Therapy

Various nonviral vector systems have been used to deliver DNA into cancer cells to induce an antitumor effect. Naked DNA encoding genes ranging from cytokine genes to tumor antigen genes have been delivered alone (63), by gene gun (64,65), or by electroporation (66,67), resulting in significantly induced cytokine levels or specific antigen expression. Electroporation has also been used to introduce plasmids that encode antisense RNA against E6 and E7 mRNA to human papilloma virus (HPV)...

Gene Replacement Therapy

Malignant cells are frequently resistant to chemotherapy and radiation-induced programmed cell death (apoptosis). Such resistance is generally the result of abnormal expression of certain oncogenes or mutations in or loss of expression of tumor suppressor genes involved in the control of apoptosis. Strategies designed to replace defective tumor suppressor genes, as well as to force expression of apoptosis-inducing genes offer promise for restoring this mode of cell death in tumor cells. The p53...

Adenoassociated Virusmediated Longterm Expression For Cancer Therapy

It is now well established that tumor growth and metastasis are dependent upon recruitment of a functional blood supply by a process known as tumor angiogenesis and the angiogenic phenotype has been shown to correlate with poor prognosis in many human tumors (88,89). The establishment of an angiogenic requirement for tumor growth led to the identification of several antiangiogenic molecules that potentially inhibit growth of tumor neovasculature (90). Antiangiogenic therapies devised so far...

Adenoviral Retargeting For Cancer Gene Therapy

A gene therapy for various disease settings requires different selectivity and targeting, highlighting the importance of choosing the right strategy for successful gene therapy. In the field of cancer gene therapy, aggressively proliferating cells need to be killed or suppressed. This unique situation demands multiple levels of function in order to achieve a therapeutic effect. First, virtually all tumor cells must be killed because any remaining viable cancer cells would lead to tumor...

Overexpression of Tumor Suppressor Genes and Apoptosis Inducing Genes

The fact that overexpression of tumor suppressor genes and apoptosis-inducing genes can induce cell-cycle arrest or apoptosis has led to numerous experimental and clinical investigations into their use as anticancer therapeutics (37,40). Transfer of various tumor suppressor genes directly into cancer cells has been demonstrated to suppress tumor growth by inducing apoptosis and cell-cycle arrest while also exerting lethal bystander effects. Adenovirus-mediated p53 gene therapy has produced...

Basic Fibroblast Growth Factor

Basic fibroblast growth factor (bFGF) was one of the first angiogenic factors to be characterized and since then has been studied extensively. It induces tube formation in collagen gels, modulates integrin expression and gap junction intercellular communication, and it upregulates VEGF, VEGFR2, and uPAR in vitro (44). bFGF stimulates both lymphangiogenesis and angiogenesis in a mouse corneal lymphangiogenesis model and up-regulats VEGF-C expression in vascular endothelial and perivascular cells...

Recombinant Aavmediated Cancer Gene Therapy As Adjuvant Therapy

Based on several studies over the last decade, it is becoming increasingly clear that gene therapy includes a repertoire of cancer treatment paradigms. At the same time, limitations in both target definition and vector efficacy need to be overcome to utilize this as an exclusive therapeutic modality. However, important to this discussion is the realization that gene therapy can be combined with other traditional treatments as an adjuvant therapy. For many of the solid tumors, surgery,...

Cytokine Modified Tumor Cell Vaccines

Antitumor vaccination with irradiated autologous cancer cells, transfected ex vivo to express cytokine genes was exemplified by the use of GM-CSF gene modified cancer cell delivery (86,99). Promising initial preclinical studies with an antitumor vaccine comprised of irradiated autologous GM-CSF secreting-Dunning rat prostate carcinoma cells led to a clinical trial in which eight patients with prostate cancer were treated with autologous GM-CSF secreting, irradiated tumor cell vaccines prepared...

History Of Parvovirus And Cancer

Since the discovery of parvoviruses, there has been significant advance on the relationship between parvoviruses and cancer. Epidemiological surveys in humans have revealed a correlation between serological evidence of parvoviral infection and lower incidence of certain human cancers (7,8). In vivo studies have demonstrated that animals infected with parvoviruses exhibited increased protection against chemical carcinogen- and virus-induced tumorigenesis (9). Several in vitro studies have also...

Methods Of Dna Vaccine Delivery 31 Electroporation

Elecroporation is a common in vitro transfection method. Through the application of electric pulses, the cellular membrane is temporarily disrupted. This, combined with physical translocation of ionic plasmid DNA (ionophoresis), can result in efficient gene transfection. In vivo, the application of electroporation involves the use of probes or clamp electrodes to the site of plasmid administration. This method has been shown to induce long-term expression of reporter gene in vivo. Adapting the...

Genetically Engineered VSV as a Gene Therapy Tool Against Cancer

Oncolytic studies indicated that wild type VSV exhibited considerable potential as an anticancer agent. However, the ability to modify VSV through genetic engineering obviously affords the prospect of creating new generations of custom-made VSV vectors that contain immunomodulatory and or suicide cassettes designed to increase their antitumor activity. In order to begin evaluating whether genetically engineered VSV carrying tumor-killing cassettes could be created and whether such viruses were...

Applications Of Retroviral Gene Transfer For Cancer Therapy

Ex Vivo Gene Therapy Using Retroviral and Lentiviral Vectors 3.1.1. Retroviral Gene Transfer to Hematopoietic Cells General Considerations The use of hematopoietic stem cells (HSC) in bone marrow transplantation approaches have convincingly demonstrated the potential of this approach to repopu-late the different hematologic lineages in mice and in humans, and has found application not only in the treatment of hereditary diseases but also in myelo-reconstitution after high-dose chemotherapy...

Herpes Simplex Virus Thymidine Kinase Gene Ganciclovir

One approach to the development of more effective therapies for prostate cancer is to initiate a cascade of molecular cellular events locally within the primary tumor that generate a localized and systemic antitumor immune response through the transfer of specific immunomodulatory genes. It has been considered that it might be possible to use specific genes to generate localized antitumor cytotoxicity as well as to initiate a systemic antitumor immune response. This strategy has evolved from...

Clinical Safety

There is extensive data regarding the overall safety of the vaccinia virus, which was generated during its use in the eradication of smallpox. The complications associated with vaccinia virus include encephalitis, vaccinia necrosum, and eczema vaccinatum. These complications are more prevalent in immunocomprimised individuals and infants (see Fig. 2) (34-36). Vaccinia associated encephalitis results from infection of the central nervous system (CNS). Studies have shown viral recovery from the...

VSV Gene Therapy and Vaccines

The generally low seroprevalence of VSV antibodies in the general population and genetic malleability indicated that VSV could be an attractive vector to develop new vaccines (26). VSV elicits strong humoral and cellular immune responses in vivo and naturally infects at mucosal surfaces (89-91). As mentioned, a major observation also included that VSV were found to accommodate large gene inserts and multiple genes in their genomes (88). Thus, it wasn't long before a variety of foreign viral...

Biological Basis Of Adenoviruses

The adenovirus was first isolated in the early 1950s as a cytopathogenic agent from primary cell cultures derived from human adenoids and respiratory secretions of patients with acute respiratory illnesses (23,24). This virus was actually a group of nonenveloped viruses containing linear, double-stranded DNA encapsulated in an icosahedral protein capsid. To date, more than 100 types of adenoviruses that infect a wide range of mammalian and avian hosts have been identified (25). At least 51...

Molecular Chemotherapy With rAAV

Delivery of a gene-encoded toxin into cancer cells to achieve tumor eradication is usually performed by indirect killing through activation by a prodrug. This approach has focused mainly on delivery of the herpes simplex virus thymidine kinase (HSV-tk) gene. Expression of HSV- tk results in replicating tumor cells having enhanced sensitivity to nucleoside analogs, such as ganciclovir (GCV) or acyclovir. GCV is phosphory-lated initially by TK and subsequently by cellular factors to a...

Richard H Pin md Maura Reinblatt md Yuman Fong md and William R Jarnagin md

Attenuation and Safety Viral Oncolytic Therapy Gene Delivery Targeting Conclusions The use of viruses to treat human malignancy is not a new concept but has only recently evolved into a clinically viable therapy. Spurred by advances in molecular biology that have allowed relatively easy manipulation of the viral genome, a number of different viruses have been evaluated and shown to have promise as anticancer agents. Of these, herpes simplex virus (HSV) has been perhaps the most intensively...

Signaling Pathways Involved In Mda7 Mediated Tumor Cell Death

There are numerous reports of MDA-7 growth-suppressor effects in tumors, and of its activation of various signaling pathways including the P-catenin PI3 kinase pathway in breast and lung cancer cells, general upregulation of BAX, p53, PKR, Fas, TNF-related apoptosis inducing ligand (TRAIL), DR4, and caspases, reduced levels of BCL-2 proteins, and down regulation of vascular endothelial growth factor (VEGF) and tumor growth factor (TGF)- mRNA, among others. The inhibition of different kinases...

Adenoassociated Virus For Cancer Gene Therapy

Similar to the APV, wild-type AAV has also been identified to possess antioncogenic properties (62,63). Although rAAV vectors are relatively less studied in cancer gene therapy, those reported so far indicate their future potential. In addition, whereas most of the cancer gene therapy strategies target tumor cells directly for increasing therapeutic benefit, targeting normal cells that regulate key events conducive for tumor growth is becoming a promising alternative for cancer therapy. For...

Recombinant Apv For Cancer Gene Therapy

Although more than 30 different APV have been identified so far, most of the work has focused on vectors that can infect human cells namely LuIII, minute virus of mice (MVM), and parvovirus H1, which are members of rodent group of parvoviruses. Following the development of recombinant vectors based on AAV packaging by transcomplementing the vector proteins, similar strategies have been successfully tested with the APV including MVM, LuIII, and H1. MVM, one of the first parvoviruses to be...

Clinical Trials

As previousely discussed, adenovectors can effectively transduce in both dividing and nondividing cells in vivo and because long-term transgene expression is not a common prerequisite for cancer therapy, adenovectors are the most commonly used vector in cancer gene therapy (Journal of Gene Medicine Website, www.wiley.co.uk genmed clinical). The genes used in adenovector-mediated cancer therapy include tumor-suppressor genes (e.g., p53, Rb, and p16), prodrug activator or suicide genes (TKand...

Mien Chie Hung PhD and Duen Hwa Yan PhD

This chapter describes preclinical development of therapeutic genes in breast cancer treatment. Beginning from targeting HER-2 neu-overexpressing breast cancer cells by adenovirus E1A, we found E1A expression had profound effects on tumor cells including growth suppression, apoptosis, and sensitization to chemo-drugs and radiation. The mechanisms of the antitumor activities as well as the preliminary results obtained from multiple E1A clinical trials are discussed. Also identified are the...

Strategies In Vaccinia Gene Therapy To Evade Immune Clearance

The clearance of the virus in vivo needs to be overcome in order to deliver an adequate amount of virus to the tumor and allow time for viral replication. Several strategies have been tested to overcome this barrier. The first strategy is to create a virus that is less recognizable by the immune system. The problem with this method is that the vaccinia virus presents a broad spectrum of antigens to the host. Hence, one or two mutations in the viral envelope would probably not be sufficient to...

Vaccinia As An Oncolytic Virus For Cancer Therapy

The concept of a tumor selective oncolytic virus that can be safely administered is very appealing and is the focus of current research by multiple laboratories. The advantages of the vaccinia virus as an oncolytic virus have been described earlier in the chapter. The most important advantage is the efficiency of viral replication, cell to cell spread and ability to destroy tissue. Development of an oncolytic virus has focused on genetic alterations of the WR strain of virus to achieve a tumor...

Kenneth Lundstrom PhD Contents

Alphavirus for the Transfection of Tumor Cell Lines Intratumoral Gene Delivery by Alphavirus Tumor Targeting of Alphavirus Vectors Production of Retrovirus-Like Particles by Alphavirus Alphavirus vectors can infect a broad range of mammalian cells both in cell cultures and in vivo. The presence of the RNA replicon generates extreme RNA levels in infected cells, which is the basis for the very high levels of heterologous gene expression. Application of replication-deficient vectors leads to...

Adenovector Mediated Cancer Gene Therapy

Roth, md Vector-Related Toxicity and Safety Issues Early-region E1 -deleted, replication-defective adenovectors have been widely used in preclinical and clinical studies of cancer gene therapy. Recently, the use of conditional replicating or oncolytic adenovectors in cancer gene therapy or virotherapy has received much attention. Clinical trials with E1-deleted adenovectors and oncolytic adenovirus have shown that adenovector-mediated cancer gene therapy is...