bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 5395: Mutant oncolytic Herpes simplex virus expressing yeast cytosine deaminase in combination with 5-FC: Viral replication and prodrug bioactivation kinetics in vivo
Authors: Yamada Suguru , Kuroda Toshihiko , Fuchs Bryan C. , He Xiaoying , Supko Jeffrey , McGinn Christopher M. , Schmitt Anthony , Lanuti Michael , Tanabe Kenneth K. 
Published: June 2012

Abstract
Background: Herpes simplex virus 1 (HSV-1) expressing yeast cytosine deaminase (yCD) is a well-characterized prodrug/enzyme system that converts 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU). However, a greater understanding of the interactions between the cellular response to 5-FC activation and viral replication is required to establish optimal dosing schedules for virus and prodrug administration.
Methods: Using the flip flop BAC system we developed a HSV-1 mutant expressing the yCD gene in the ICP6 locus in the HSV strain Patton, termed bMP6-CMVFcumB. BALB/c mice with MC26 flank tumors were treated by intratumoral injection of bMP6-CMVFcumB and 5-FC was administered intraperitoneally at different initiation times for 6 days. We also investigated different durations of 5-FC administration after initiation on Day 3 after viral injection. To measure viral replication and transgene expression, MC26 tumors on flanks were harvested at different time points between Day 0 and Day 21 following virus injection. Tumor lysates were analyzed by quantitative real-time PCR to assess genomic HSV-DNA, viral plaque assay to assess replicative virions and LacZ staining to assess transgene expression. 5-FU levels in serum and tumor were measured by HPLC at specific time points following administration of 5-FC on Day 3 after viral injection.
Results: Intratumoral viral genomic DNA copy number and viral titers peaked on Day 3 after viral injection and gradually decreased afterwards. And consistent with this, 5-FC administration on Day 3 post viral injection was more effective than administration on Day 6. Virus was detected for as long as 2 weeks after viral injection. And consistent with this finding, administration of 5-FC for 12 days was superior to 6 days, and administration for 18 days provided no added benefit over 12 days. The peak level of 5-FU in tumors was seen on Day 6 after viral injection and this value decreased gradually afterwards. Analysis of serum samples demonstrated that 5-FU was present at very low levels on Day 6, but it could not be detected at any other time.
Conclusion: Viral replication and transgene expression can be effectively monitored over time and correlated with therapeutic response. Our results suggest that the most potent effect by this combination therapy is observed when 5-FC is initiated at the onset of peak viral and transgene expression and continued for the duration of expression.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5395. doi:10.1158/1538-7445.AM2011-5395
Abstract 5403: Pro-apoptotic properties of Bag-1 peptides in the control of prostate cancer cell growth
Authors: Maddalo Danilo 
Published: June 2012

Abstract
Purpose of the study: The purpose of the study is to identify sequence(s) in Bag-1 proteins responsible for growth inhibition and to eventually derive a short peptide for cancer therapy.
Introduction: Bag-1 family of proteins consists of four members (Bag- 1L, 1M, 1 and 1S) originating from different translation-initiation sites on the same mRNA. Clinical reports have shown a dual role of the Bag-1 proteins in tumor progression and in the inhibition of tumor growth. In this work we have identified a 19 amino acid sequence in the Bag-1 proteins that reduces prostate cancer cell growth ex vivo and in vivo.
Experimental procedures: Inhibition of prostate cancer cell growth was analyzed in clonogenic assay and in athymic nude mouse xenograft models. Histological analysis for apoptosis was carried out on paraffin-embedded tumor samples. Structural analyses were carried out by NMR and circular dichroism. Interaction partners of the Bag-1 peptides were analyzed by GST-pull down and by co-immunoprecipitation assays. Significance of cellular levels of glucose-regulated proteins (GRP) 75 and 78 for the growth inhibitory action of the peptide was demonstrated by RNA interference experiments.
Results: Overexpression of Bag-1 proteins in 22Rv.1 prostate tumor cells reduced the growth of these cells in a colony forming assay. A study making use of several deletion mutants identified a 69 amino acid Bag-1 sequence as responsible for the growth inhibition. NMR and circular dichroism studies showed this peptide to be unstructured but it nonetheless interacted with the substrate binding domain of GRP 75 and 78. The cellular levels of the GRPs were shown by RNA interference studies to be essential for the action of the peptide. Overexpression of the peptide in the 22Rv1 cells decreased growth in proliferation assay and in xenograft tumor models. The decreased growth in vivo was demonstrated to be due to apoptosis of the Bag-1 peptide expressing cells as showed by immuohistochemical analysis. The growth inhibitory activity could be narrowed down to a 7 amino acid core within a 19 amino acid Bag-1 peptide sequence. Amino acid exchanges in the core region impaired binding of the peptide to the GRPs and inhibition of tumor cell growth. Colony formation assay using a wide panel of prostate cells showed that the 19 amino acid peptide inhibits growth of only malignant but not benign cells and this correlates with the level of expression of the two GRP target proteins in the cells.
Conclusion: Together these results demonstrate that a short peptide sequence derived from Bag-1 proteins that binds GRP75/78 specifically inhibits the growth of prostate cancer cells.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5403. doi:10.1158/1538-7445.AM2011-5403
Abstract 5405: Apoptosis induction in cancer cells by the simultaneous transduction of p53 and artificial miRNAs based on the screening of genome-wide shRNA library
Authors: Idogawa Masashi , Sasaki Yasushi , Kashima Lisa , Shinomura Yasuhisa , Imai Kohzoh , Tokino Takashi 
Published: June 2012

Abstract
Gene transfer involving p53 is viewed as a potentially effective cancer therapy, but does not result in a good therapeutic response in all human cancers. Several p53 target genes have an inhibitory effect on p53-mediated apoptosis. Therefore, if the induction of these genes by p53 is selectively suppressed, the therapeutic effectiveness would be improved.
In previous study, we constructed a replication-deficient recombinant adenovirus that encoded co-cistronic p53 and artificial microRNAs (miRNAs) targeting p21, a representative p53 target gene which have an anti-apoptotic effect, resulting in p53 expression and the suppression of p21 induction simultaneously. In colorectal and hepatocellular carcinoma cells, the infection with the adenovirus vector augmented apoptosis and suppressed tumor growth as compared to an adenovirus that expressed p53 alone in vitro and in vivo.
In this study, we simultaneously infected the vectors which express artificial miRNAs targeting other anti-apoptotic genes and evaluated the therapeutic effectiveness of p53 expression in combination with the suppression of several anti-apoptotic p53 target genes. Co-infection with these vectors suppressed the induction of anti-apoptotic target genes and induced apoptosis more efficiently in cancer cells.
To identify other RNAi targets which prevent p53-induced apoptosis, we have screened the genome-wide lentiviral shRNA library in the cancer cells which resist p53-induced apoptosis. After the infection with p53 or control adenovirus, the cell populations expressing each shRNA were quantified by microarray. As a result, we found that several cell populations expressing specific shRNAs were significantly decreased in p53-infected cells compared with control cells. This result indicated that the suppression of specific targets by RNAi restored the apoptotic response by p53 transduction in cancer cells which originally resist p53-induced apoptosis.
These results suggest that the transduction of p53 and specific miRNAs may be effective as a cancer therapy.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5405. doi:10.1158/1538-7445.AM2011-5405
Abstract 541: The oral proteasome inhibitor ONX 0912 has bone anabolic effects in addition to anti-myeloma effects
Authors: Hurchla Michelle A. , Hornick Mary C. , Li Aixiao , Collins Lynne , Kirk Christopher J. , Piwnica-Worms David , Vij Ravi , Tomasson Michael H. , Weilbaecher Katherine N. 
Published: June 2012

Abstract
Multiple Myeloma (MM) is a cancer of antibody producing plasma cells in which tumors largely reside in and destroy the bone microenvironment. Drugs that inhibit proteasomal degradation of intracellular proteins such as those crucial for cell growth, have demonstrated significant efficacy in the treatment of MM. ONX 0912, is a next generation proteasome inhibitor that acts irreversibly and has the significant advantage of oral delivery. Pharmacokinetic data suggest that the in vivo serum half life of ONX 0912 is approximately 4 hours. We found that a physiologic 4 hour pulse treatment with low nanomolar doses of ONX 0912 effectively decreased the viability of human MM cell lines through the inhibition of proliferation and induction of apoptosis with similar efficacy as continuous drug administration in vitro. Because MM induces significant bone loss through the tumoral production of factors involved in the recruitment of bone resorping osteoclasts (OC) and suppression of bone forming osteoblasts (OB), we also evaluated the effects of ONX 0912 on bone cell viability and function. Bortezomib, an intravenous proteasome inhibitor in clinical use with a serum half-life of one hour, has been reported to suppress OC viability and enhance OB function. We found that culturing of primary murine macrophages, preosteoclasts, and OC under continuous incubation with bortezomib and ONX 0912 decreased cell viability, although at doses greater than 100-fold higher than those affecting MM cells. However, when primary macrophages and OC were incubated with a physiologic 1 hour pulse of bortezomib or 4 hour pulse of ONX0912, these cells were resistant to killing with in vitro osteoclastogenesis being modestly inhibited. In contrast, physiologic 4 hour pulse exposure of ONX 0912 to primary OB cultures, resulted in enhanced in vitro differentiation and mineralization. Likewise, oral administration of ONX 0912 to non-tumor bearing C57BL/6 mice significantly increased trabecular bone volume and bone mineral density. We then evaluated the effect of ONX 0912 on MM tumor burden and tumor associated bone loss in vivo. Oral administration of ONX 0912 significantly reduced the growth of human RPMI8226 MM cells in long bones of NOD-SCID-IL-2Rγc-/- mice and protected mice from bone loss compared to vehicle treated mice. These data suggest that, in addition to its anti-tumor effects, ONX 0912 may also shift the bone microenvironment during MM from a catabolic state to an anabolic state, reducing osteolysis, promoting bone formation and decreasing skeletal complications of MM.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 541. doi:10.1158/1538-7445.AM2011-541
Abstract 5411: Development of SCLC specific nanoparticle-mediated therapeutic gene delivery
Authors: Kamat Chandrashekhar D. , Shmueli Ron B. , Sunshine Joel C. , Connis Nick , Green Jordan J. , Hann Christine L. 
Published: June 2012

Abstract
Lung cancer is the most common cause of cancer-related deaths worldwide. Small cell lung cancer (SCLC) is a particularly aggressive form of lung cancer characterized by early metastatic behavior. Even with currently recommended therapy, the average survival of SCLC patients is less than 1 year. There is an urgent need for novel treatments. The majority (70-90%) of SCLC cases possess alterations in p53 and Rb. This relative genetic homogeneity makes SCLC an attractive context in which to develop and test novel gene therapy approaches. We have initiated studies using non-viral, poly-β amino acid ester (PBAE) nanoparticle delivery of gene therapy in SCLC. PBAE polymers possess numerous advantages over viral delivery systems such as structural diversity, cost effectiveness, low immunogenicity and higher stability. PBAEs encapsulate DNA to form biodegradable cationic nanoparticles and have been studied in a variety of cancer cell types and in primary endothelial cells. This is the first study of PBAEs in SCLC.
A PBAE polymer library was screened in two SCLC lines using a luciferase-based high-throughput screen (HTS). Thirty-two of 112 polymers were further characterized in the H446 SCLC cell line using a CMV-GFP reporter construct and analyzed by qualitative (microscopy) and quantitative (flow cytometry) methods. This secondary screen revealed that the polymers had variable transfection efficiencies ranging from 8-55%. Four polymers, 446LG, 447LG, 456LG and 457 exhibited high transfection efficiencies (42-55%) in two SCLC cell lines, including one suspension line. Using PBAEs complexed with Cy5-labeled DNA, we were able to demonstrate that &gt;90% cells bind and internalize the nanoparticles. We have initiated studies to better elucidate bottlenecks between nanoparticle uptake and gene expression. Additionally, preliminary studies in tumor-bearing athymic nude mice demonstrated gene uptake and expression via intratumoral injection of 457 and 446LG polymer/DNA complexes.
Ongoing studies include further optimization of PBAEs for in vitro gene expression and systemic in vivo delivery. In parallel, we are performing genetic characterization of patient-derived primary SCLC xenografts to verify relevant gene targets. Taken together, our data supports further development of a non-viral PBAE-based gene delivery approach in SCLC.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5411. doi:10.1158/1538-7445.AM2011-5411
Abstract 5413: Is a non-conjugated triple-helix forming oligonucleotide targeting the genomic HPRT locus capable of sequence specific mutagenesis
Authors: Reshat Reshat , Priestley Catherine , Fellows Mick , O'Donovan Mike , Gooderham Nigel J. 
Published: June 2012

Abstract
Oligonucleotide strands have been shown to be capable of binding to duplex DNA in a sequence specific manner to form a triple-helix or triplex structure. Such phenomenons have been shown to induce mutation, as demonstrated using plasmid-based reporter constructs (Wang et al 1996, Science, 271, p802). These studies have engendered concern from the European Medicines Agency (EMEA) in regard to biotechnology derived pharmaceuticals such that antisense oligonucleotides may also form triplex structures in a sequence specific manner at genomic DNA with potentially mutagenic effects. In this study, we have examined the mutagenic potential of a non-conjugated triplex forming oligonucleotide (TFO27) targeting the genomic hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus. The mutagenicity of TFO27 was assessed using the human lymphoblastoid TK6 cell line through 6-thioguanine resistance (6TGr).
Electrophoretic mobility shift assays were used to demonstrate triplex formation by TFO27 at the target motif at sub-nanomolar concentrations. As expected, a control oligonucleotide, SCR27, failed to form a triplex at the target motif. Subsequently, a range of transfection facilitators were evaluated for optimal delivery of a fluorescently labelled oligonucleotide probe.
In preliminary experiments treating 3×106 cells, TFO27 appeared to produce a dose dependent increase in 6TGr mutants. Furthermore, TFO27 failed to induce mutation at the non-targeted thymidine kinase (TK) locus suggesting locus specificity for its mode of action. Moreover, SCR27 failed to induce mutation at both loci. However, TFO27 failed to induce mutation at the HPRT locus in experiments treating 10×106 cells. Increasing the oligonucleotide concentration had no effect on the number of 6TGr recovered.
These contradictory findings are difficult to explain, but emphasise the importance of using appropriate target cell numbers in mutation assays. Overall, our data would suggest that triplex formation could occur in cells but chromatin structure, intranuclear pH, ion concentrations and nucleases are all potential barriers that probably influence the dynamics of triplex formation and stability. In view of these factors, we suggest that studies of the mutagenic potential of triplex formation are better performed at genomic loci rather than extra-chromosomal test systems.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5413. doi:10.1158/1538-7445.AM2011-5413
Abstract 5414: Novel tissue-targeted adenoviral vector for squamous cell carcinoma therapy expressing cell cycle regulator cdk2ap1 and molecular imaging genes
Authors: Zolochevska Olga , Figueiredo Marxa L. 
Published: June 2012

Abstract
Oral squamous cell carcinoma (OSCC) affects about 30,000 Americans each year, and although the overall prognosis has improved in recent years for localized carcinomas, metastases can decrease survival rates by half. For tongue and palate lesions, surgery is usually the initial treatment, but metastases aggressively develop at sites where conventional therapies are ineffective. Therefore, our goal has been to develop more effective therapeutic modalities for the disease utilizing expression of cell cycle arrest and apoptosis-modulating genes. Our efforts have focused on gaining understanding of the biology and therapeutic potential of p12cdk2ap1 (p12), an S-phase growth suppressor and proapoptotic gene commonly downregulated in OSCC. In vivo, we have showed that expressing p12 using a nonviral vector can result in effective reduction in tumor size and a dramatically altered tumor phenotype. Moreover, we have showed that p12 can have cell growth inhibitory effects in a cell-autonomous as well as non-cell autonomous manner, rendering expression of this cell cycle regulator a very promising new gene therapy strategy. Therefore, we hypothesized that this growth regulator molecule will comprise a highly efficient antiumor gene therapy for OSCC. We have developed a novel viral delivery vector system with high activity and high specificity expression in oral tumor cells. This Adenovirus (Ad) utilizes a two-step transcriptional amplification system driven by the SCCA2 promoter and a bidirectional target cassette containing the sequences for the p12 and ether firefly luciferase (Luc) or thymidine kinase (TK) imaging genes. We constructed and are characterizing novel configurations of these dE1dE3 Ad-SCCA2-p12/Luc or p12/TK bidirectional vectors for gene therapy and molecular imaging applications. We are currently testing the specificity of these vectors and their effectiveness in tumor growth inhibition at either floor of mouth, orthotopic, or distant sites following intratumoral or systemic administration. We propose this new vector design may hold promise not only as a novel SCC-specific gene therapy but perhaps as a molecular imaging detection agent for tumor cells that have metastasized to distant and thus difficult to treat sites.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5414. doi:10.1158/1538-7445.AM2011-5414
Abstract 5419: The plant alkaloid ellipticine is detoxified by cytochrome P450 1A1/2 (CYP 1A1/2) but activated and forms DNA adducts if CYP1A1 or 1A2 is combined with cytochrome b5: an explanation for an in vivo/in vitro discrepancy
Authors: Frei Eva , Kotrbova Vera , Martinek Vaclav , Breuer Andrea , Stiborova Marie 
Published: June 2012

Abstract
Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b] carbazole) is an alkaloid with anti-cancer activity elicited by interfering with many cellular functions. One of these is the formation of DNA adducts upon activation by CYP or peroxidases. The metabolites responsible for detoxication or DNA adduct formation have been characterised and CYP3A1 and the othologous human enzyme CYP3A4 are the most efficient activating enzymes in microsomes from either species (Stiborová M et al. Cancer Res 64 (2004) 8374-8380). In vivo also CYP1A effectively activate ellipticine to DNA adducts, while isolated CYP1A1/2 detoxify ellipticine mainly to its 9-hydroxy derivative. Cytochrome b5 has been shown to modulate CYP catalysis by either transferring the second electron to CYPs, or by allosteric interaction thereby leading to higher CYP enzyme activity (Schenkman, J.B., I. Jansson Pharmacol. Ther. 97(2003) 139-52). Isolated cytochrome b5 was added to isolated CYP1A1 or 1A2 reconstituted with NADPH-CYP reductase in liposomes at different ratios of the three enzymes. Apo-cytochrome b5 (containing no heme) was generated in transfected E.coli (Kotrbová V. et al. Protein Expr Purif., 66(2009) 203-209) and used as such or reconstituted with heme or Mn-protoporphyrin IX. Metabolites were analysed by HPLC and UV detection and quantified with standards. DNA adducts were determined by the nuclease P1 version of the 32P-postlabeling assay. With both CYP1A1 and 1A2 the pattern of ellipticine metabolites in incubations containing cytochrome b5 shifted from detoxication to activation. This shift depended on the ratio of CYP1A to cytochrome b5 with optimal yield of 12-hydroxy- and 13-hydroxy ellipticine at a ratio of 1:5, CYP1A to cytochrome b5. The shift was more pronounced for CYP1A1 than for 1A2 leading to 6.5 fold higher DNA adduct levels than without cytochrome b5 correlating with 6 fold higher 13-hydroxy-ellipticine amounts, the metabolite responsible for the major deoxyguanosin adduct. The cytochrome b5 holo-enzyme is necessary for this effect, since neither the apo-enzyme nor the apo-enzyme reconstituted with Mn-protoporphyrin IX had the same effect. Other heme containing proteins, like myoglobin or cytochrome c had no effect. Ellipticine is, to our knowledge, the first xenobiotic compound where cytochrome b5 shifts the metabolism by CYP from detoxication to activation and DNA adduct formation. This is important also when analysing the pharmacological effects in vivo, since ellipticine induces both CYP1A and cytochrome b5.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5419. doi:10.1158/1538-7445.AM2011-5419