• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.477-483
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• 2005

Corynebacterium ammoniagenes ATCC 6872, which does not accumulate pyrimidine nucleoside or nucleotide, was metabolically engineered to secrete a large amount of thymidine. Characteristics of 5-fluorouracil resistance ($FU^r$), hydroxyurea resistance ($HU^r$), trimethoprim resistance ($TM^r$), thymidylate phosphorylase deficiency ($deoA^-$), inosine auxotrophy ($ino^-$), 5-fluorocytosine resistance ($FC^r$), thymidine kinase deficiency, and thymidine resistance ($thym^r$) were successively introduced into mutant strains KR3 and DY5T9-5, and shake-flask cultures were able to accumulate 408.1 mg/l and 428.2 mg/l of thymidine, respectively, as a major product. The mutant strains did not accumulate thymine at all and accumulated less than 10 mg/l of other pyrimidine nucleosides, such as cytosine, cytidine, and deoxycytidine, as byproducts.

• Animal cells and systems
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• v.2 no.3
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• pp.355-359
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• 1998

Among the proteins secreted from Lactobacillus acidophilus KCTC 3151, a 36 kDA and 24 kDa protein, whose amounts were relatively abundant, were purified and their N-terminal amino acid sequences determined. The N-terminal amino acid sequence of 36 kDa protein exhibited high homology with thymidine phosphorylase and glyceraldehyde-3-phosphate dehydrogenase. The N-terminal amino acid sequence of the 24 kDa protein did not show significant homology with proteins in Protein Data Base nor Gene Bank. Nucleotide sequence of the gene encoding 36 kDa protein indicates that the protein possesses the domains for a-helical, phosphate binding and pyrimidine binding sites, which are also shown in thymidine phosphorylases. Also, the protein contains conserved domains of dehydrogenase II and III. However, the activity of thymidine phosphorylase or glyceraldehyde-3-puospnate dehydrogenase could not be detected in the purified fractions of the 36 kDa protein.

• Journal of Microbiology
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• v.41 no.4
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• pp.340-344
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• 2003

The group I intron from Tetrahymena thermophila has been demonstrated to employ splicing reactions with its substrate RNA in the trans configuration. Moreover, we have recently shown that the transsplicing group I ribozyme can replace HCV-specific transcripts with a new RNA that exerts anti-viral activity. In this study, we explored the potential use of RNA replacement for cancer treatment by developing trans-splicing group I ribozymes, which could replace tumor-associated RNAs with the RNA sequence attached to the 3' end of the ribozymes. Thymidine phosphorylase (TP) RNA was chosen as a target RNA because it is known as a valid cancer prognostic factor. By performing an RNA mapping strategy that is based on a trans-splicing ribozyme library, we first determined which regions of the TP RNA are accessible to ribozymes, and found that the leader sequences upstream of the AUG start codon appeared to be particularly accessible. Next, we assessed the ribozyme activities by comparing trans-splicing activities of several ribozymes that targeted different regions of the TP RNA. This assessment was performed to verify if the target site predicted to be accessible is truly the most accessible. The ribozyme that could target the most accessible site, identified by mapping studies, was the most active with high fidelity in vitro. Moreover, the specific trans-splicing ribozyme reacted with and altered the TP transcripts by transferring an intended 3' exon tag sequence onto the targeted TP RNA in mammalian cells with high fidelity. These results suggest that the Tetrahymena ribozyme can be utilized to replace TP RNAs in tumors with a new RNA harboring anti-cancer activity, which would revert the malignant phenotype.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.408-416
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• 2019

Purpose: To study the efficacy of capecitabine or S-1 plus oxaliplatin (CAPOX or SOX) for treating thymidine phosphorylase (TP)- or dihydropyrimidine dehydrogenase (DPD)-positive advanced gastric cancer. Materials and Methods: Eighty-six patients with stage IIIC to IV gastric cancer were assessed for TP and DPD expression by immunohistochemistry. The association between CAPOX or SOX efficacy and TP/DPD expression was retrospectively analyzed. Results: There were no significant differences in the objective remission rate (ORR, 52.27% vs. 47.62%; P>0.05), disease control rate (72.73% vs. 73.81%, P>0.05), progression-free survival (hazard ratio [HR], 1.119; 95% confidence interval [CI], 0.739-1.741; P=0.586), and overall survival (OS; HR, 0.855; 95% CI, 0.481-1.511; P=0.588) between CAPOX and SOX. A higher number of stage IV patients showed TP positivity, while DPD-positive patients predominantly showed intestinal type of gastric cancer. In TP-positive patients, the ORRs associated with CAPOX and SOX treatments were 57.14% and 38.10%, respectively; OS was better with CAPOX than with SOX (HR, 0.447; 95% CI, 0.179-0.978; P=0.046). Among DPD-positive patients, the SOX treatment-associated ORR (60.87%) was significantly higher than the CAPOX treatment-associated ORR (43.48%). Furthermore, SOX treatment resulted in better OS than did CAPOX treatment (HR, 2.020; 95% CI, 1.019-4.837; P=0.049). Conclusions: No significant difference in clinical efficacy was found between CAPOX and SOX. TP-positive patients might respond better to CAPOX while DPD-positive patients may respond better to SOX. Our findings might serve as a guide for personalized chemotherapy for gastric cancer.

• Molecules and Cells
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• v.28 no.2
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• pp.119-124
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• 2009

Anti cancer agent 5-FU (Fluoro Uracil) is a prodrug that can be metabolized and then activated to interfere with RNA and DNA homeostasis. However, the majority of administered 5-FU is known to be catabolized in vivo in the liver where Dihydropyrimidine dehydrogenase (DPD) is abundantly expressed to degrade 5-FU. The biological factors that correlate with the response to 5-FU-based chemotherapy have been proposed to include uridine phosphorylase (UPP), thymidine phosphorylase (TPP), p53 and microsatellite instability. Among these, the expression of UPP is known to be controlled by cytokines such as $TNF-{\alpha}$, IL1 and $IFN-{\gamma}$. Our preliminary study using a DNA microarray technique showed that basic fibroblast growth factor (bFGF) markedly induced the expression of UPP1 at the transcription level. In the present study, we investigated whether bFGF could modulate the expression of UPP1 in osteo-lineage cells and examined the sensitivity of these cells to 5-FU mediated apoptosis.

• Genomics & Informatics
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• v.2 no.1
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• pp.45-52
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• 2004

The self-splicing group I intron from Tetrahymena thermophila has been demonstrated to perform splicing reaction with its substrate RNA in the trans configuration. In this study, we explored the potential use of the trans-splicing group I ribozymes to replace a specific RNA with a new RNA that exerts any new function we want to introduce. We have chosen thymidine phosphorylase (TP) RNA as a target RNA that is known as a valid cancer prognostic factor. Cancer-specific expression of TP RNA was first evaluated with RT-PCR analysis of RNA from patients with gastric cancer. We determined next which regions of the TP RNA are accessible to ribozymes by employing an RNA mapping strategy, and found that the leader sequences upstream of the AUG start codon appeared to be particularly accessible. A specific ribozyme recognizing the most accessible sequence in the TP RNA with firefly luciferase transcript as a 3' exon was then developed. The specific trans-splicing ribozyme transferred an intended 3' exon tag sequence onto the targeted TP transcripts, resulting in a more than two fold induction of the reporter activity in the presence of TP RNA in mammalian cells, compared to the absence of the target RNA. These results suggest that the Tetrahymena ribozyme can be a potent anti-cancer agent to modify TP RNAs in tumors with a new RNA harboring anti-cancer activity.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.11-16
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• 1988

Various Benzylacyclouridine (BAU, HM-BAU, suc-BAU, BBAU, HMBBAU, suc-BBAU, and BBBAU) developed as specifc inhibitors of uridine phosphorylase (UrdPase), inhibit transport (zero-trans influx) of ridine (Urd) in human erythrocytes. The inhibition pattern of these compounds is competitive, though suc-BBAU and BBBAU show a slight noncompetivieness. The order of potency as an inhibitor of the nucleoside transport system is BBAU ${\sim}$ HM-BBAU ${\sim}$ suc-BBAU > BBBAU > BAU ${\sim}$ suc-BAU ${\sim}$ HM-BAU ($K_1$ values of 19, 23, 38, 112, 124, 174 and 176 ${\mu}M$, respectively). These data indicate that there is a differnece in potency of Urd transport inhibition between the analogs of BAU and BBAU. Further, the potency correlates with the hydrophobicity of the compound, but it has a limit in the size of $C_5$ substitution. Abbreviation: BAU (5-benzylacyclouridine), 5-benzyl-1-(2'-hydroxyethoxymethyl) uracil; HM-BAU (3'-hydroxymethyl-BAU), 5-benzyl-1- [(1',3'-dihydroxy-2-propoxy) methyl]uracil; suc-BAU, 3'-succinyl-BAU; BBAU (benzyloxybenzylacyclouridine), 5-( m-benzyloxybenByl)-1-(2'-hydroxyethoxymethyl)uracil; HM-BBAU (3'-hydroxymethyl-BBAU), 5-(m-benzyloxybenzyl)-1- [(1'3'-dihyd.oxy-2-p.epoxy)methyll u.acil; suc-BAU, 3'-succinyl-BBAU; BBBAU, 5- f 3-(4-benzyloxyben-Eyl)benzyll -1-(2'-hydroxyethoxymethyl)uracil; Urdpase, uridine phosphorylase; Urd, Uridine; Fd-Urd, 5-fluoro-2'-deoxyuridine; AcThd, aoyclothyrnidine; AcUrd, acyclouridine; dThd, thymidine; NBMPR, nitrobenzylthioisone; FUra, 5-fluorouracil.

• Advances in pediatric surgery
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• v.8 no.2
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• pp.101-106
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• 2002

The antiangiogenic effects of novel agent KJ3, Betulinic acid, and Fumagillin on the neovascularization were studied by examining ultrastructural alterations in the vasculature of synthetic gelform and mouse neuroblastoma C1300. Small pieces of gelform with 0.4% agar were introduced subcutaneously (s.c.) in 7 week old male CH3/HeJ mice. After the $LD_{50}s$ were determined by FACS analysis, a third of $LD_{50}$ of three drugs were injected either locally or intraperitoneally every other day for 14 days. A/J mice were inoculated s.c. with the C1300 neuroblastoma cell line, then either saline or three drugs were injected in the same manner. The antiangiogenic effects of three drugs were studied by measuring the histologic changes in tumors, and immunostaining for CD34, VIII/vWF, CD105, and thymidine phosphorylase. In the drug treated groups, the number of vessels in gelform experiments and C1300 neuroblastoma experiments were lower than the corresponding values in the control. The histologic findings were significantly different in drug treated groups on day 7, but these were not significant on day 14. These results imply that antiangiogenic agents were effective when the tumor burden is minimal.