Adenovirus-mediated ribonucleotide reductase R1 gene therapy of human colon adenocarcinoma (original) (raw)
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International journal of oncology, 2006
GTI-2501 is a 20-mer oligonucleotide that is complementary to a coding region in the mRNA of R1, the large subunit of ribonucleotide reductase (RNR). In vitro studies, have demonstrated that GTI-2501 decreases mRNA and protein levels of R1 in a sequence-specific and dose-dependent manner. Furthermore, GTI-2501 inhibits the growth of human lung, liver, ovary, brain, melanoma, breast and pancreatic tumor cells in colony forming assays. In vivo studies have shown that GTI-2501 significantly inhibits growth of human colon, pancreas, lung, breast, renal, ovarian, melanoma, brain glioblastoma-astrocytoma, and prostatic tumors in CD-1 nude, Balb/c nude and/or SCID mice. GTI-2501 treatment caused total regression of human breast and renal tumor xenografts in mice. These effects are not observed with a scrambled control oligonucleotide containing the same base content but not complementary to R1. GTI-2501 specifically inhibits metastasis of human melanoma cells to the lungs in CD-1 athymic n...
A review of Ribonucleotide reductase and cancer therapies
2017
Mammalian Ribonucleotide reductase (RNR) provides the precursors needed for both DNA synthesis and repair process. Recent study shows RNR including RRM2 have been associated with various types of cancer and many studies imply that it plays biological roles in promoting cancer development. The important role plays by RNR, and its subunits RRM1, RRM2, and p53R2 in DNA synthesis and repair had found to be an attractive target for anticancer therapies. Usually targeting RNR in cancer treatment using known inhibitors, or new inhibitors that discovered using as molecular docking programs. This comprehensive strategy can be used to find new indications of clinically used drugs that failed during its development. Thus, this strategy has the advantages of cost reduction and bypasses the safety concerns by in silico evaluation of the inhibitor biological activity on the molecular target. This review compiles studies on the structure, function, and regulation activity of RNR in cancer; the rol...
Oncology Letters, 2017
Reduced expression in immortalized cells (REIC)/Dickkopf-3 (Dkk-3) overexpression, induced using an adenovirus (Ad)-REIC, has been revealed to have a dramatic therapeutic effect on multiple types of cancer. To achieve an improved therapeutic effect from Ad-REIC on cancer, our group previously developed an enhanced gene expression system, the C-TSC cassette [cytomegalovirus (CMV)-RU5' located upstream (C); another promoter unit composed of triple tandem promoters, human telomerase reverse transcriptase (hTERT), simian virus 40 and CMV, located downstream of the cDNA (TSC); plus a polyadenylation (polyA) signal]. When applied to the conventional Ad-REIC, this novel system induced the development of an enhanced product, Ad-C-TSC-REIC, which exhibited a noticeable anticancer effect. However, there were difficulties in terms of Ad-C-TSC-REIC productivity in HEK293 cells, which are a widely used donor cell line for viral production. Productivity of Ad-C-TSC-REIC was significantly reduced compared with the conventional Ad-REIC, as the Ad-C-TSC-REIC had a significantly higher ability to induce apoptotic cell death of not only various types of cancer cell, but also HEK293 cells. The present study aimed to overcome this problem by modifying the C-TSC structure, resulting in an improved candidate: A C-T cassette (C: CMV-RU5' located upstream; T: another promoter unit composed of a single hTERT promoter, located downstream of the cDNA plus a polyA signal), which demonstrated gene expression comparable to that of the C-TSC system. The improved adenovirus REIC/Dkk-3 product with the C-T cassette, named Ad-C-T-REIC, exhibited a higher expression level of REIC/Dkk3, similar to that of Ad-C-TSC-REIC. Notably, the vector mitigated the cell death of donor HEK293 cells, resulting in a higher rate of production of its adenovirus. These results indicated that Ad-C-T-REIC has the potential to be a useful tool for application in cancer gene therapy.
Suppression of Lung Tumor Formation by the Regulatory Subunit of Ribonucleotide Reductase
2006
The nucleotide metabolism enzyme ribonucleotide reductase is composed of a regulatory subunit (RRM1) and a catalytic subunit (RRM2). The RRM1 locus has frequent loss of heterozygosity in lung cancers, ectopic expression of RRM1 suppresses proliferation of ras-transformed mouse fibroblasts, and high levels of RRM1 expression are associated with a significant survival benefit in patients with lung cancer. In RRM1 transgenic human lung and colon cancer cell lines, we observed induction of G 2 cell cycle arrest, apoptosis, and efficient DNA damage repair. We generated strains of RRM1 transgenic mice and found that carcinogen-induced lung tumor formation was significantly suppressed. The tumor suppression was more pronounced in strains with high levels of RRM1 expression than in those with low levels of expression. DNA damage repair capacity in transgenic animals was determined, and RRM1 transgenic animals repaired chemically induced DNA damage with greater efficiency than control animals. We conclude that the regulatory subunit of ribonucleotide reductase has tumor suppressor activity that is mediated through efficient DNA damage repair. (Cancer Res 2006; 66(13): 6497-502)
1995
We have demonstrated previously the utility of this approach using a hammerhead ribozyme designed to cleave the mutant sequence in codon 12 of the activated H-ras oncogene transcript. To develop this strategy into a practical means to approach malignant disease, methods must be devel oped to accomplish high efficiency delivery of the ribozyme to target neoplastic cells. To accomplish this, a recombinant adenovirus was de signed that encoded a gene cassette for the H-ras ribozyme. By using this virus, it was possible to accomplish high efficiency reversion of the neo plastic phenotype in mutant H-ras expressing tumor cells without the need for any selection steps. The demonstration of the utility of adenoviralmediated delivery of anticancer ribozymes will allow the practical devel opment of gene therapy strategies on this basis.
Oncology Reports, 2013
Gene expression systems with various promoters, including the cytomegalovirus (CMV) promoter, have been developed to increase the gene expression in a variety of normal and cancer cells. In particular, in the clinical trials of cancer gene therapy, a more efficient and robust gene expression system is required to achieve sufficient therapeutic outcomes. By inserting the triple translational enhancer sequences of human telomerase reverse transcriptase (hTERT), Simian virus 40 (SV40) and CMV downstream of the sequence of the BGH polyA, we were able to develop a novel gene expression system that significantly enhances the expression of the genes of interest. We termed this novel gene expression cassette the super gene expression (SGE) system, and herein verify the utility of the SGE cassette for a replicationdeficient adenoviral vector. We newly developed an adenoviral vector expressing the tumor suppressor, reduced expression in immortalized cells (REIC)/Dickkopf-3 (Dkk-3), based on the CMV promoter-driven SGE system (Ad-SGE-REIC) and compared the therapeutic utility of Ad-SGE-REIC with that of the conventional adenoviral vectors (Ad-CMV-REIC or Ad-CAG-REIC). The results demonstrated that the CMV promoter-SGE system allows for more potent gene expression, and that the Ad-SGE-REIC is superior to conventional adenoviral systems in terms of the REIC protein expression and therapeutic effects. Since the SGE cassette can be applied for the expression of various therapeutic genes using various vector systems, we believe that this novel system will become an innovative tool in the field of gene expression and gene therapy.
Human Cell, 2002
In order to develop an effective therapeutic intervention for patients with pancreatic cancer, we examined the genetic alternations of pancreatic cancer. Based on these results, we are developing a new gene therapy targeting the genetic character of pancreatic cancer using mutant adenoviruses selectively replicationcompetent in tumor cells. Loss of heterozygosity of 30% or more were observed on chromosome arms 17p (47%). 9p (45%), 18q (43%), 12q (34%), and 6q (30%). LOH of 12q,17p, and 18q showed the s i m c a n t association with poor prognosis. These data strongly suggest that mutation of the putative suppressor genes, TP53 and SMAD4 play significant roles in the disease progression. Based on this rationale, we are developing a new gene therapy targeting tumors without normal "53 function. ElB55kDadeleted adenovirus (AxElAdB) can selectively replicate in TP53deficient human tumor cells but not cells with functional TP53. We evaluated the therapeutic effect of this AxElAdB on pancreatic cancer without normal TP53 function. The growth of human pancreatic tumor in SCID mice model was markedly inhibited by the consecutive injection of AxElAdB. Furthermore, AxElAdB is not only the strong weapon but also useful canier of genes possessing anti-tumor activities as a virus vector specific to tumors without normal TP53 function. It was reported that uracil phosphoribosyl transferase (UPRT) overcomes 5FU resistance. UPHT catalyzes the synthesis of Sfluorouridine monophosphate FUMP) from Uracil and phosphoribosylpyrophosphate (PRPP). The antitumor effect of 5FU is enhanced by augmenting Sfluorodeoxyuridme monophosphate (FdUMP) converted from FUMP, which inhibits Thymidylate Synthetase (73). The therapeutic advantage of restricted replication competent adenovirus that expresses UPRT (AxElAdBUPRT) was evaluated in an intra-peritoneal disseminated tumor model. To study the anti-tumor effect of AxElAdB-UPRT/5FU, mice with disseminated AsPC-1 tumors were administered the adenovirus, followed by the 5FU treatment It was shown that the treatment with AxElAdBUPRT/5FU caused a dramatic reduction of the disseminated tumor burden without toxicity in normal tissues. These results revealed that the AxElAdBUPHT/5FU system is a promising tool for intraperitoneal dissen+ated pancreatic cancer.
Ribonucleotide Reductase: A Critical Enzyme for Cancer Chemotherapy and Antiviral Agents
Recent Patents on Anti-Cancer Drug Discovery, 2007
Ribonucleotide Reductase (RNR) plays a critical role in DNA synthesis, and is a well-recognized target for cancer chemotherapeutic and antiviral agents. RNR inhibition precludes DNA transcription and repair, from which results cell apoptosis. Many regulation checkpoints concerning RNR activity have been unravelled through the last two decades, with potential use to inhibit enzyme activity. This was accomplished by researchers from different but complementary areas, and from which several and different inhibitors have resulted. The volume of these studies has generated over 4000 articles since the discovery of RNR in 1960.