1
|
Tong AW, Zhang YA, Cunningham C, Maples P, Nemunaitis J. Potential clinical application of antioncogene ribozymes for human lung cancer. Clin Lung Cancer 2004; 2:220-6. [PMID: 14700482 DOI: 10.3816/clc.2001.n.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Non-small-cell lung cancer frequently contains oncogenetic defects (mutations in ras, retinoblastoma, and p53 genes) that contribute to disease pathophysiology. Recent studies and clinical trials have focused on gene therapy approaches that either replace the function of defective tumor-suppressor genes such as p53 or inactivate mutant oncogenes such as ras. Ribozymes are RNA molecules with highly specific intrinsic enzymatic activity against target RNA sequences, which can discriminate mutant sequences that differ by a single base from their wild-type counterparts. Following binding to the RNA substrate by base-pair complementation, the ribozyme cleaves the target RNA irreversibly, then releases itself for new rounds of subsequent cleavage, resulting in significantly improved target:effector stoichiometry as compared with antisense oligonucleotides of the same specificity. Transcript-specific ribozymes have been used extensively for experimental oncogene inactivation. Ribozymes are effective for targeting mutant ras, p53, or the multidrug-resistant gene product for lung cancer cells in vitro. However, their in vivo effect is not well defined against this malignancy. We recently characterized the antitumor properties of an anti-K-ras ribozyme specific for the K-ras codon 12 mutation (GGT-->GTT). When delivered as a transgene by an adenoviral vector (ADV), the K-ras ribozyme (KRbz) suppressed growth of lung tumor xenografts expressing the relevant mutation, whereas the corresponding antisense sequence lacking catalytic activity did not. Multiple intratumoral (3-5) injections of KRbz-ADV were effective in producing complete tumor regressions of preexisting tumor xenografts. Clinical trials are under consideration to examine the applicability of this anti-K-ras ribozyme for treatment of non-small-cell lung cancers expressing the relevant mutation.
Collapse
Affiliation(s)
- A W Tong
- Cancer Immunology Research Laboratory, Baylor University Medical Center, Dallas, TX 75246, USA.
| | | | | | | | | |
Collapse
|
2
|
Zhang YA, Nemunaitis J, Scanlon KJ, Tong AW. Anti-tumorigenic effect of a K-ras ribozyme against human lung cancer cell line heterotransplants in nude mice. Gene Ther 2000; 7:2041-50. [PMID: 11175317 DOI: 10.1038/sj.gt.3301331] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Approximately 15-30% of human non-small cell lung cancers (NSCLC) carry K-ras mutations, among which point mutations at codon 12 are the most common. This study characterizes the anti-tumor effect of an anti-K-ras ribozyme adenoviral vector (KRbz-ADV; replication-deficient, E1-deleted Ad5 backbone) against NSCLC lines that express the relevant mutation (K-ras codon 12 GGT --> GTT; H441 and H1725). KRbz-ADV significantly inhibited tumor cell growth (38-94% reduction by 3H-thymidine uptake) in a time- and dose-dependent manner, but produced minimal growth inhibition on normal epithelial cells, or NSCLC H1650 cells that lack the relevant mutation. The in vivo anti-tumorigenic effect of KRbz-ADV treatment was characterized with cell line xenografts in nu/nu mice. Pre-treatment with KRbz-ADV (10 or 20 p.f.u. per cell) completely abrogated subcutaneous engraftment of H441 (n = 13) or H1725 cells (n = 8), as compared with a 100% tumor take and progressive tumor growth in animals that received untreated tumor cells, or control vector (luciferase-adenovirus/Luc-ADV)-treated tumor cells. Pre-treatment with a mutant anti-K-ras ribozyme adenoviral vector (mutKRbz-ADV), which has the same specificity as KRbz but lacks ribozyme catalytic activity, did not produce an anti-tumorigenic effect. The in vivo effect of KRbz-ADV treatment was further examined by initiating injections (2 x 10(9) p.f.u.) at 7 days after tumor induction. Pre-existing tumor growth was reduced by 39% by a single intratumoral injection. Repeat injections (three or five KRbz-ADV-intratumoral injections at 2 x 10(9) p.f.u. every other day) resulted in complete tumor regression in five of seven mice. In contrast, single or multiple injections of control vector Luc-ADV did not significantly alter tumor xenograft outcome. Ribozyme expression was confirmed in H441 cells that demonstrated reduced growth after KRbz-ADV treatment. Reduced growth corresponded to significantly lowered levels of K-ras mRNA, as defined by RT-PCR (51% of untreated level, n = 3) and RNase protection assay (56% of untreated level, n = 4) analyses. Further, 37.5% of KRbz-ADV-treated cells underwent apoptosis, as compared with 11.7%, and 19.0% in untreated and Luc-ADV-treated cultures, respectively. A significantly higher proportion of KRbz-ADV-treated H441 cells (58.2%) underwent apoptosis when maintained under anchor-independent conditions that simulate in vivo tumorigenesis ('anoikis'). This is the first report that demonstrates that KRbz-ADV can effectively inhibit in vivo tumorigenesis, and produces regression of pre-existing human lung tumor xenografts having the relevant K-ras mutation.
Collapse
Affiliation(s)
- Y A Zhang
- Mary C Crowley Cancer Research Program, Baylor Research Institute, Baylor University Medical Center, Dallas, TX 75246, USA
| | | | | | | |
Collapse
|
3
|
Turner PC. Ribozymes. Their design and use in cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 465:303-18. [PMID: 10810635 DOI: 10.1007/0-306-46817-4_26] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- P C Turner
- School of Biological Sciences, University of Liverpool, UK
| |
Collapse
|
4
|
Kijima H, Scanlon KJ. Ribozyme as an approach for growth suppression of human pancreatic cancer. Mol Biotechnol 2000; 14:59-72. [PMID: 10911615 DOI: 10.1385/mb:14:1:59] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ribozymes (catalytic RNAs, RNA enzymes) are effective modulators of gene expression because of their simple structure, site-specific cleavage activity, and catalytic potential, and have potentially important implications for cancer gene therapy. Point mutations in the K-ras oncogene are found in approx 90% of human pancreatic carcinomas, and can be used as potential targets for specific ribozyme-mediated reversal of the malignant phenotype. In this study, we focused on in vitro manipulation of ribozyme targeting of the mutated K-ras oncogene in a human pancreatic carcinoma cell line. We evaluated the efficacy of an anti-K-ras hammerhead ribozyme targeted against GUU-mutated codon 12 of the K-ras gene in cultured pancreatic carcinoma cell lines. The anti-K-ras ribozyme significantly reduced cellular K-ras mRNA level (GUU-mutated codon 12) when the ribozyme was transfected into the Capan-1 pancreatic carcinoma cells. The ribozyme inhibited proliferation of the transfected Capan-1 cells. These results suggested that this ribozyme is capable of reversing the malignant phenotype in human pancreatic carcinoma cells.
Collapse
Affiliation(s)
- H Kijima
- Department of Pathology, Tokai University School of Medicine, Isehara, Kanagawa.
| | | |
Collapse
|
5
|
Tsuchida T, Kijima H, Oshika Y, Tokunaga T, Abe Y, Yamazaki H, Tamaoki N, Ueyama Y, Scanlon KJ, Nakamura M. Hammerhead ribozyme specifically inhibits mutant K-ras mRNA of human pancreatic cancer cells. Biochem Biophys Res Commun 1998; 253:368-73. [PMID: 9878544 DOI: 10.1006/bbrc.1998.9789] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have evaluated the efficacy of an anti-K-ras hammerhead ribozyme targeted against GUU-mutated codon 12 of the K-ras gene in a cell-free system as well as in cultured pancreatic carcinoma cell lines. In the cell-free system, the anti-K-ras ribozyme specifically cleaved K-ras RNA with GUU-mutation at codon 12, but not other triplet sequences at codon 12 of K-ras RNA. In the cell culture system, the anti-K-ras ribozyme significantly reduced K-ras mRNA level (GUU-mutated codon 12) in Capan-1 pancreatic carcinoma cells, but less significantly suppressed K-ras mRNA in Capan-2 (GUU/GGU heterozygous-mutation at codon 12) or MIA PaCa-2 (UGU-mutated codon 12) pancreatic carcinoma cells. The ribozyme inhibited proliferation of transfected Capan-1 cells. These results suggest that this ribozyme selectively recognizes single-base mutation of K-ras mRNA and is able to reverse the malignant phenotype in human pancreatic carcinoma cells.
Collapse
Affiliation(s)
- T Tsuchida
- Department of Pathology, Tokai University School of Medicine, Isehara, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Ribozymes as Biotherapeutic Tools for the Modulation of Gene Expression. Gene Ther 1998. [DOI: 10.1007/978-3-662-03577-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
7
|
Abstract
The delineation of gene function has always been an intensive subject of investigations. Recent advances in the synthesis and chemistry of oligonucleotides have now made these molecules important tools to study and identify gene function and regulation. Modulation of gene expression using oligonucleotides has been targeted at different levels of the cellular machinery. Triplex forming oligonucleotides, as well as peptide nucleic acids, have been used to inhibit gene expression at the level of transcription; after binding of these specific oligonucleotides, conformational change of the DNA's helical structure prevents any further DNA/protein interactions necessary for efficient transcription. Gene regulation can also be achieved by targeting the translation of mRNAs. Antisense oligonucleotides have been used to down-regulate mRNA expression by annealing to specific and determined region of an mRNA, thus inhibiting its translation by the cellular machinery. The exact mechanism of this type of inhibition is still under intense investigation and is thought to be related to the activation of RNase H, a ribonuclease that is widely available that can cleave the RNA/DNA duplex, thus making it inactive. Another well-characterized means of interfering with the translation of mRNAs is the use of ribozymes. Ribozymes are small catalytic RNAs that possess both site specificity and cleavage capability for an mRNA substrate, inhibiting any further protein formation. This review describes how these different oligonucleotides can be used to define gene function and discusses in detail their chemical structure, mechanism of action, advantages and disadvantages, and their applications.
Collapse
Affiliation(s)
- L D Curcio
- Department of General and Oncologic Surgery, City of Hope National Medical Center, Duarte, CA 91010, USA
| | | | | |
Collapse
|
8
|
|
9
|
Affiliation(s)
- A Irie
- Department of Cancer Research, Berlex Biosciences, Richmond, California 94804-0099, USA
| | | | | |
Collapse
|
10
|
Irie A, Kijima H, Ohkawa T, Bouffard DY, Suzuki T, Curcio LD, Holm PS, Sassani A, Scanlon KJ. Anti-oncogene ribozymes for cancer gene therapy. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 1997; 40:207-57. [PMID: 9217927 DOI: 10.1016/s1054-3589(08)60141-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- A Irie
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, California 91010, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Affiliation(s)
- P L Coletta
- Molecular Medicine Unit, University of Leeds, St. James's University Hospital, Leeds, U.K
| | | | | |
Collapse
|
12
|
Lipkowitz MS, Klotman ME, Bruggeman LA, Nicklin P, Hanss B, Rappaport J, Klotman PE. Molecular therapy for renal diseases. Am J Kidney Dis 1996; 28:475-92. [PMID: 8840936 DOI: 10.1016/s0272-6386(96)90457-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The introduction of molecular therapy through the delivery of nucleic acids either as oligonucleotides or genetic constructs holds enormous promise for the treatment of renal disease. Significant barriers remain, however, before successful organ-specific molecular therapy can be applied to the kidney. These include the development of methods to target the kidney selectively, the definition of vectors that transduce renal tissue, the identification of appropriate molecular targets, the development of constructs that are regulated and expressed for long periods of time, the demonstration of efficacy in vivo, and the demonstration of safety in humans. As the genetic and pathophysiologic basis of renal disease is clarified, obvious targets for therapy will be defined, for example, polycystin in polycystic kidney disease, human immunodeficiency virus (HIV) type 1 in HIV-associated nephropathy, alpha-galactosidase A in Fabry's disease, insulin in diabetic nephropathy, and the "minor" collagen IV chains in Alport's syndrome. In addition, several potential mediators of progressive renal disease may be amenable to molecular therapeutic strategies, such as interleukin-6, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), and transforming growth factor-beta(TGF-beta). To test the in vivo efficacy of molecular therapy, appropriate animal models for these disease states must be developed, an area that has received too little attention. For the successful delivery of genetic constructs to the kidney, both viral and nonviral vector systems will be required. The kidney has a major advantage over other solid organs since it is accessible by many routes, including intrarenal artery infusion, retrograde delivery through the uroexcretory pathways, and ex vivo during transplantation. To further restrict expression to the kidney, tropic vectors and tissue-specific promoters also must be developed. For the purpose of inhibition of endogenous or exogenous genes, current therapeutic modalities include the delivery of antisense oligodeoxynucleotides or ribozymes. For these approaches to succeed, we must gain a much better understanding of the nature of their transport into the kidney, requirements for specificity, and in vivo mechanisms of action. The danger of a rush to clinical application is that superficial approaches to these issues will likely fail and enthusiasm will be lost for an area that should be one of the most exciting developments in therapeutics in the next decade.
Collapse
Affiliation(s)
- M S Lipkowitz
- Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
Ohta Y, Kijima H, Ohkawa T, Kashani-Sabet M, Scanlon KJ. Tissue-specific expression of an anti-ras ribozyme inhibits proliferation of human malignant melanoma cells. Nucleic Acids Res 1996; 24:938-42. [PMID: 8600463 PMCID: PMC145712 DOI: 10.1093/nar/24.5.938] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In this study, we have compared the efficacy of a tissue-specific promoter (tyrosinase promoter) with a viral promoter to express anti-ras ribozyme RNA in human melanoma cells. The retroviral vector containing the tyrosinase promoter was superior in its ability to suppress the human melanoma phenotype in vitro as characterized by changes in growth, melanin synthesis, morphology and H-ras gene expression. These data support the use of tissue-specific expression of anti-oncogene ribozymes as a rational therapeutic strategy in human cancers.
Collapse
Affiliation(s)
- Y Ohta
- Department of Medical Oncology, City of Hope National Medical Center, Duarte, CA 91010, USA
| | | | | | | | | |
Collapse
|
14
|
Ohta Y, Kijima H, Kashani-Sabet M, Scanlon KJ. Suppression of the malignant phenotype of melanoma cells by anti-oncogene ribozymes. J Invest Dermatol 1996; 106:275-80. [PMID: 8601728 DOI: 10.1111/1523-1747.ep12340688] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The activation of signal transduction pathways by mutation or overexpression of cellular oncogenes has been associated with neoplastic transformation. In this study, we addressed the therapeutic potential of ribozymes targeted against the activated H-ras oncogene as well as against the nuclear proto-oncogenes c-fos and c-myc in the FEM human melanoma cell line containing a H-ras mutation. FEM cells transfected with the anti-ras ribozyme were shown to have the longest doubling time, the least DNA synthesis, and the fewest colonies in soft agar when compared with transfectants with ribozymes against c-fos or c-myc mRNA. Furthermore, anti-ras ribozyme clones showed a dendritic appearance in monolayer culture that was associated with enhanced melanin synthesis. These results suggest that the anti-ras ribozyme could affect not only the proliferation but also the differentiation process of human melanoma cells in vitro. They also reinforce the role of anti-oncogene ribozymes as suppressors of the neoplastic phenotype of melanoma cells.
Collapse
Affiliation(s)
- Y Ohta
- Department of Medical Oncology, City of Hope Medical Center, Duarte, CA 91010, USA
| | | | | | | |
Collapse
|
15
|
|
16
|
Rak J, Filmus J, Finkenzeller G, Grugel S, Marmé D, Kerbel RS. Oncogenes as inducers of tumor angiogenesis. Cancer Metastasis Rev 1995; 14:263-77. [PMID: 8821090 DOI: 10.1007/bf00690598] [Citation(s) in RCA: 170] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Dominantly acting transforming oncogenes are generally considered to contribute to tumor development and progression by their direct effects on tumor cell proliferation and differentiation. However, the growth of solid tumors beyond 1-2 mm in diameter requires the induction and maintenance of a tumor blood vessel supply, which is attributed in large part to the production of angiogenesis promoting growth factors by tumor cells. The mechanisms which govern the expression of angiogenesis growth factors in tumor cells are largely unknown, but dominantly acting oncogenes may have a much greater impact than hitherto realized. An example of this is the induction of expression of vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) by mutant H- or K-ras oncogenes, as well as v-src and v-raf, in transformed fibroblasts or epithelial cells. Besides VEGF/VPF, mutant ras genes are known to upregulate the expression of a variety of other growth factors thought to have direct or indirect stimulating effects on angiogenesis, e.g. TGF-beta and TGF-alpha. This effect may be mediated through the ras-raf-MAP kinase signal transduction pathway, resulting in activation of transcription factors such as AP1, which can then bind to relevant sites in the promoter regions of genes encoding angiogenesis growth factors. In principle, similar events could take place after activation or overexpression of many other oncogenes, especially those which can mediate their function through ras-dependent signal transduction pathways. The regulatory effect of oncogenes on mediators of angiogenesis has some potentially important therapeutic consequences. For example, it strengthens the rationale of pharmacologically targeting oncogene products, such as mutant RAS proteins, as an anti-tumor therapeutic strategy. Such drugs may attack the source of one or more angiogenic growth factors and by doing so, function, at least in part, as anti-angiogenic agents in vivo.
Collapse
Affiliation(s)
- J Rak
- Division of Cancer Biology Research, Sunnybrook Health Science Centre, Toronto, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
17
|
Deshane J, Siegal GP, Alvarez RD, Wang MH, Feng M, Cabrera G, Liu T, Kay M, Curiel DT. Targeted tumor killing via an intracellular antibody against erbB-2. J Clin Invest 1995; 96:2980-9. [PMID: 8675670 PMCID: PMC186010 DOI: 10.1172/jci118370] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Specific killing of erbB-2-overexpressing tumor cells can be achieved using expression of an intracellular antibody directed against the erbB-2 oncoprotein. We have developed a strategy using a recombinant adenovirus encoding an anti-erbB-2 single chain antibody to achieve targeted tumor cell killing in vivo and can show significantly prolonged survival of animals carrying a human ovarian carcinoma tumor burden within their peritoneal cavities. This strategy of gene therapy for ovarian carcinoma offers the potential to achieve highly specific, targeted killing of human tumor cells and thus establishes the rationale to undertake human clinical trials on this basis.
Collapse
Affiliation(s)
- J Deshane
- Gene Therapy Program, University of Alabama at Birmingham, 35294, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
Nucleic acids are increasingly being considered for therapeutic uses, either to interfere with the function of specific nucleic acids or to bind specific proteins. Three types of nucleic acid drugs are discussed in this review: aptamers, compounds which bind specific proteins; triplex forming (antigene) compounds; which bind double stranded DNA; and ribozymes (catalytic RNA), which bind and cleave RNA targets. The binding of aptamers to protein may involve specific sequence recognition, although this is not always the case. The interaction of triplex forming oligonucleotides or ribozymes with their targets always involves specific sequence recognition and hybridization. Early optimism concerning the possibility of designing drugs without a priori knowledge of the structure of the target (except a nucleotide sequence) has been tempered by the finding that target structure has a dramatic effect upon the hybridization potential of the nucleic acid drug. Other obstacles to the creation of effective nucleic acid drugs are their relative high molecular weight (> 3300) and their sensitivity to degradation. The molecular weight of these compounds has created a significant delivery problem which needs to be solved if nucleic acid drugs are to become effective therapies.
Collapse
Affiliation(s)
- R A Stull
- Department of Pharmacy, University of California, San Francisco 94143-0446, USA
| | | |
Collapse
|