Crystal structure of pyrimidine-nucleoside phosphorylase from Bacillus subtilis in complex with imidazole and sulfate.

Pyrimidine-nucleoside phosphorylase catalyzes the phosphorolytic cleavage of thymidine and uridine with equal activity. Investigation of this protein is essential for anticancer drug design. Here, the structure of this protein from Bacillus subtilis in complex with imidazole and sulfate is reported at 1.9 Šresolution, which is an improvement on the previously reported structure at 2.6 Šresolution. The localization and position of imidazole in the nucleoside-binding site reflects the possible binding of ligands that possess an imidazole ring.

[Purine and pyrimidine nucleoside phosphorylases - remarkable enzymes still not fully understood]. / Nukleozydowe fosforylazy purynowe i pirymidynowe - niezwykle enzymy ciagle nie do konca rozszyfrowane.

Purine and pyrimidine nucleoside phosphorylases catalyze the reversible phosphorolytic cleavage of the glycosidic bond of purine and pyrimidine nucleosides, and are key enzymes of the nucleoside salvage pathway. This metabolic route is the less costly alternative to the de novo synthesis of nucleosides and nucleotides, supplying cells with these important building blocks. Interest in nucleoside phosphorylases is not only due to their important role in metabolism of nucleosides and nucleotides, but also due to the potential medical use of the enzymes (all phosphorylases in activating prodrugs - nucleoside and nucleic base analogs, high-molecular mass purine nucleoside phosphorylases in gene therapy of some solid tumors) and their inhibitors (as selective immunosuppressive, anticancer and antiparasitic agents, and preventing inactivation of other nucleoside drugs). Phosphorylases are also convenient tools for efficient enzymatic synthesis of otherwise inaccessible nucleoside analogues. In this paper the contribution of Professor David Shugar and some of his colleagues and coworkers in studies of these remarkable enzymes carried out over nearly 40 years is discussed on the background of global research in this field.

Pregnancy in women undergoing hemodialysis: case series in a Southeast Brazilian reference center / Gestação em mulheres em tratamento hemodialítico: série de casos em um centro de referência do Sudeste do Brasil

PURPOSE: To describe maternal and neonatal outcomes in pregnant women undergoing hemodialysis in a referral center in Brazilian Southeast side. METHODS: Retrospective and descriptive study, with chart review of all pregnancies undergoing hemodialysis that were followed-up at an outpatient clinic of high- risk prenatal care in Southeast Brazil. RESULTS: Among the 16 women identified, 2 were excluded due to follow-up loss. In 14 women described, hypertension was the most frequent cause of chronic renal failure (half of cases). The majority (71.4%) had performed hemodialysis treatment for more than one year and all of them underwent 5 to 6 hemodialysis sessions per week. Eleven participants had chronic hypertension, 1 of which was also diabetic, and 6 of them were smokers. Regarding pregnancy complications, 1 of the hypertensive women developed malignant hypertension (with fetal growth restriction and preterm delivery at 29 weeks), 2 had acute pulmonary edema and 2 had abruption placenta. The mode of delivery was cesarean section in 9 women (64.3%). All neonates had Apgar score at five minutes above 7. CONCLUSIONS: To improve perinatal and maternal outcomes of women undergoing hemodialysis, it is important to ensure multidisciplinary approach in referral center, strict control of serum urea, hemoglobin and maternal blood pressure, as well as close monitoring of fetal well-being and maternal morbidities. Another important strategy is suitable guidance for contraception in these women. .

OBJETIVOS: Descrever os resultados maternos e neonatais de mulheres grávidas que estavam em tratamento de hemodiálise em um centro de referência no Sudeste brasileiro. MÉTODOS: Estudo retrospectivo e descritivo, com revisão de prontuários de todas as gestações em hemodiálise, acompanhadas no pré-natal especializado da região Sudeste do Brasil. RESULTADOS: Entre as 16 mulheres identificadas, 2 foram excluídas devido à perda de seguimento. Das 14 descritas, a hipertensão foi a causa mais frequente de insuficiência renal crônica (50% dos casos). A maioria (71,4%) realizava tratamento de hemodiálise há mais de um ano e todas elas foram submetidas a 5 ou 6 sessões por semana. Onze mulheres tinham hipertensão crônica, 1 das quais também era diabética, e 6 eram fumantes. Em relação às complicações da gravidez, 1 das mulheres hipertensas desenvolveu hipertensão maligna (com restrição de crescimento fetal e parto prematuro com 29 semanas), 2 tiveram edema pulmonar agudo e 2 apresentaram descolamento prematuro de placenta. O tipo de parto foi cesariana em 9 mulheres (64,3%). Todos os recém-nascidos tiveram Apgar aos cinco minutos maior que 7. CONCLUSÕES: Para melhorar os resultados perinatais e maternos de mulheres em hemodiálise, é importante ter uma abordagem multidisciplinar em centro de referência, um controle rigoroso da uremia, hemoglobina e pressão arterial materna, bem como acompanhar de perto o bem-estar fetal e a morbidade materna. Outra estratégia importante é a orientação adequada para contracepção nessas mulheres. .

A socialização da medicina na era do adhemarismo / The socialization of medicine in the era of São Paulo Governor Adhemar de Barros

A análise observa as conexões entre o processo de profissionalização dos médicos paulistas e políticas de saúde do governo estadual de Adhemar de Barros em São Paulo (1947-1951), em meio a amplas mudanças na área de saúde denominadas pelos médicos paulistas “socialização da medicina”. Reconhecemos aspectos ambivalentes para o profissionalismo médico diante desse governo populista, como: a luta médica pela equiparação ante os advogados servidores públicos estaduais; a criação de uma secretaria de saúde estadual; e certos elos contraditórios entre a área de saúde adhemarista e a ideologia e a organização profissionais da medicina paulista. Nesse particular, o artigo aprofunda a análise de manifestações ideológicas de importantes lideranças médicas paulistas.

The article analyzes how the process of the professionalization of physicians in São Paulo related to healthcare policy under the administration of São Paulo governor Adhemar de Barros (1947-1951) during a period of broad change in the realm of health known by São Paulo physicians as the “socialization of medicine.” Medical professionalism confronted certain ambivalences under this populist administration, including doctors’ struggle to achieve pay equal to that of state public attorneys; the establishment of a state health department; and some contradictory ties between the area of health under Adhemar and the professional ideology and organization of medicine in São Paulo. The article undertakes a more in-depth analysis of the ideological manifestations of important leaders in the state’s medical community.

Predictive factors of alcohol and tobacco use in adolescents / Fatores preditivos do uso de álcool e tabaco em adolescentes / Factores predictivos del uso de alcohol y tabaco en los adolescentes

OBJECTIVES: to analyze the effect of self-esteem, assertiveness, self-efficacy and resiliency on alcohol and tobacco consumption in adolescents. METHOD: a descriptive and correlational study was undertaken with 575 adolescents in 2010. The Self-Esteem Scale, the Situational Confidence Scale, the Assertiveness Questionnaire and the Resiliency Scale were used. RESULTS: the adjustment of the logistic regression model, considering age, sex, self-esteem, assertiveness, self-efficacy and resiliency, demonstrates significance in the consumption of alcohol and tobacco. Age, resiliency and assertiveness predict alcohol consumption in the lifetime and assertiveness predicts alcohol consumption in the last year. Similarly, age and sex predict tobacco consumption in the lifetime and age in the last year. CONCLUSION: this study can offer important information to plan nursing interventions involving adolescent alcohol and tobacco users. .

OBJETIVOS: analisar o efeito da autoestima, assertividade, autoeficácia e resiliência sobre o consumo de álcool e tabaco em adolescentes. MÉTODO: estudo descritivo correlacional com 575 adolescentes, realizado no ano 2010. Foram utilizadas a Escala de Autoestima, o Questionário de Confiança Situacional, o Questionário de Assertividade e a Escala de Resiliência. RESULTADOS: o ajuste do modelo de regressão logística, considerando a idade, sexo, autoestima, assertividade, autoeficácia e resiliência foi significante em relação ao consumo de álcool e tabaco. A idade, resiliência e assertividade foram preditores do consumo de álcool em algum momento na vida e a idade e a assertividade foram preditores no último ano. Para o consumo de tabaco, a idade e o sexo foram preditores em algum momento na vida e a idade no último ano. CONCLUSÃO: este estudo pode proporcionar informações importantes para o planejamento de intervenções de enfermagem em adolescentes usuários de álcool e tabaco .

OBJETIVOS: analizar el efecto de la autoestima, asertividad, autoeficacia y resiliencia sobre el consumo de alcohol y tabaco en adolescentes. MÉTODO: descritivo correlacional con 575 adolescentes, en 2010. Se utilizaron la Escala de Autoestima, el Cuestionario de Confianza Situacional, el Cuestionario de Asertividad y la Escala de Resiliencia. RESULTADOS: el ajuste del modelo de regresión logística, considerando la edad, sexo, autoestima, asertividad, autoeficacia y resiliencia, muestra significancia en el consumo de alcohol y tabaco. La edad, resiliencia y asertividad predicen el consumo de alcohol alguna vez en la vida y la edad y asertividad en el último año. De la misma forma la edad y sexo predicen el consumo de tabaco alguna vez en la vida y la edad en el último año. CONCLUSIÓN: este estudio puede proporcionar información importante para la planificación de intervenciones en enfermería de los adolecentes usuarios de alcohol y tabaco. .

The pyrimidine nucleoside phosphorylase of Mycoplasma hyorhinis and how it may affect nucleoside-based therapy.

Mycoplasmas are opportunistic parasites and some species are suggested to preferentially colonize tumor tissue in cancer patients. We could demonstrate that the annotated thymidine phosphorylase (TP) gene in the genome of Mycoplasma hyorhinis encodes a pyrimidine nucleoside phosphorylase (PyNPHyor) that not only efficiently catalyzes thymidine but also uridine phosphorolysis. The kinetic characteristics of PyNPHyor-catalyzed nucleoside and nucleoside analogue (NA) phosphorolysis were determined. We demonstrated that the expression of such an enzyme in mycoplasma-infected cell cultures dramatically alters the activity of various anticancer/antiviral NAs such as 5-halogenated pyrimidine nucleosides, including 5-trifluorothymidine (TFT). Due to their close association with human cancers, the presence of mycoplasmas may markedly influence the therapeutic efficiency of nucleoside-based drugs.

Nucleoside-catabolizing enzymes in mycoplasma-infected tumor cell cultures compromise the cytostatic activity of the anticancer drug gemcitabine.

The intracellular metabolism and cytostatic activity of the anticancer drug gemcitabine (2',2'-difluoro-2'-deoxycytidine; dFdC) was severely compromised in Mycoplasma hyorhinis-infected tumor cell cultures. Pronounced deamination of dFdC to its less cytostatic metabolite 2',2'-difluoro-2'-deoxyuridine was observed, both in cell extracts and spent culture medium (i.e. tumor cell-free but mycoplasma-containing) of mycoplasma-infected tumor cells. This indicates that the decreased antiproliferative activity of dFdC in such cells is attributed to a mycoplasma cytidine deaminase causing rapid drug catabolism. Indeed, the cytostatic activity of gemcitabine could be restored by the co-administration of tetrahydrouridine (a potent cytidine deaminase inhibitor). Additionally, mycoplasma-derived pyrimidine nucleoside phosphorylase (PyNP) activity indirectly potentiated deamination of dFdC: the natural pyrimidine nucleosides uridine, 2'-deoxyuridine and thymidine inhibited mycoplasma-associated dFdC deamination but were efficiently catabolized (removed) by mycoplasma PyNP. The markedly lower anabolism and related cytostatic activity of dFdC in mycoplasma-infected tumor cells was therefore also (partially) restored by a specific TP/PyNP inhibitor (TPI), or by exogenous thymidine. Consequently, no effect on the cytostatic activity of dFdC was observed in tumor cell cultures infected with a PyNP-deficient Mycoplasma pneumoniae strain. Because it has been reported that some commensal mycoplasma species (including M. hyorhinis) preferentially colonize tumor tissue in cancer patients, our findings suggest that the presence of mycoplasmas in the tumor microenvironment could be a limiting factor for the anticancer efficiency of dFdC-based chemotherapy. Accordingly, a significantly decreased antitumor effect of dFdC was observed in mice bearing M. hyorhinis-infected murine mammary FM3A tumors compared with uninfected tumors.

Inhibition of pyrimidine and purine nucleoside phosphorylases by a 3,5-dichlorobenzoyl-substituted 2-deoxy-D-ribose-1-phosphate derivative.

The 3,5-dichlorobenzoyl-substituted 2-deoxy-D-ribose-1-phosphate derivative, designated Cf2891, was found to inhibit a variety of pyrimidine and purine nucleoside phosphorylases (NPs) with preference for uridine- and inosine-hydrolyzing enzymes [uridine phosphorylase (UP; EC 2.4.2.3), pyrimidine nucleoside phosphorylase (PyNP; EC 2.4.2.2) and purine nucleoside phosphorylase (PNP; EC 2.4.2.1)]. Kinetic analyses revealed that Cf2891 competes with inorganic phosphate (P(i)) for binding to the NPs and, depending on the nature of the enzyme, acts as a competitive or non-competitive inhibitor with regard to the nucleoside binding site. Also, the compound prevents breakdown of pyrimidine analogues used in the treatment of viral infections and cancer. Since NPs are abundantly present in tumor tissue and may be overexpressed due to secondary bacterial infections in immunocompromised patients suffering viral infections, Cf2891 may serve as a lead molecule for the development of inhibitors to be used in nucleoside-based combination therapy.

Phosphoramidate ProTides of the anticancer agent FUDR successfully deliver the preformed bioactive monophosphate in cells and confer advantage over the parent nucleoside.

The fluorinated pyrimidine family of nucleosides continues to represent major current chemotherapeutic agents for treating solid tumors. We herein report their phosphate prodrugs, ProTides, as promising new derivatives, which partially bypass the dependence of the current drugs on active transport and nucleoside kinase-mediated activation. They are also resistant to metabolic deactivation by phosphorolytic enzymes. We report 39 ProTides of the fluorinated pyrimidine FUDR with variation in the aryl, ester, and amino acid regions. Notably, only certain ProTide motifs are successful in delivering the nucleoside monophosphate into intact cells. We also find that the ProTides retain activity in mycoplasma infected cells, unlike FUDR. Data suggest these compounds to be worthy of further progression.

The relationship between clinicopathological factors and the reduction of pyrimidine nucleoside phosphorylase activity after preoperative administration of 5'-deoxy-5-fluorouridine.

AIM: The response to fluoropyrimidine chemotherapeutic drugs is different in individual tumors. Predictive biomarkers of antitumor effects by these drugs are unknown. 5'-Deoxy-5-fluorouridine (5'-DFUR), a fluoro-pyrimidine chemotherapeutic drug, is converted to 5-fluorouracil (5-FU) by pyrimidine nucleoside phosphorylase (PyNPase). It is suggested that 5'-DFUR will efficiently exert antitumor effects via PyNPase in tumor tissues. The change of PyNPase activity in tumor tissues following 5'-DFUR administration may reflect antitumor effects, and may be useful for detecting predictive factors of antitumor effects. The aim of this study was to search for predictive factors of antitumor effects by analyzing the relationship between clinicopathological factors and the change of PyNPase activity in colorectal tumor tissues after preoperative 5'-DFUR administration. PATIENTS AND METHODS: PyNPase activity in colorectal tissues from 45 patients with colorectal tumors was measured using an ELISA method. RESULTS: The reduction rate of PyNPase activity in colorectal tumor tissues after preoperative 5'-DFUR administration was correlated with significant differences in lymphatic invasion, stage, and histologic classification. It is suggested that lymphatic invasion, stage (distant metastasis), and histologic classification may be predictive factors for evaluating antitumor effects and selecting 5-FU-based chemotherapeutic drugs for patients with colorectal tumors.

[Significance of pyrimidine nucleoside phosphorylase and dihydropyrimidine dehydrogenase levels to predict postoperative recurrence in primary breast cancer].

BACKGROUND: High expression of PyNPase (pyrimidine nucleoside phosphorylase) and DPD (dihydropyrimidine dehydrogenase) in breast cancer has been reported. Breast cancer patients with high expression of PyNPase reportedly have a poor prognosis. METHODS: We evaluated the relationship between postoperative prognosis, and clinicopathological factors including HER2 expression and the levels of PyNPase and DPD in breast cancer. PyNPase and DPD levels in tumors and nontumorous tissues were examined by enzyme-linked immunosorbent assay (ELISA). RESULTS: PyNPase and DPD levels in tumors were significantly higher than in non-tumorous tissues (p<0.001). The DPD levels in tumors associated with> or =2+expression of HER2 were significantly higher than in others (p=0.014). Disease-free survival in patients with<100 U/mg protein of PyNPase levels or<4 of PyNPase/DPD ratio was significantly better compared with others (p=0.022, p=0.014). CONCLUSION: PyNPase/DPD ratio may be a new prognostic marker in breast cancer.

Tissue levels of pyrimidine nucleoside phosphorylase activity in human and rodent bladder cancer and normal bladder tissue.

OBJECTIVES: To assess the relationship between the tissue levels of pyrimidine nucleoside phosphorylase (PyNpase) and clinicopathological parameters in human bladder cancer and to investigate the PyNpase levels in rat and mouse urinary bladder initiated by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). METHODS: The PyNpase levels in tumor tissue, normal tissue adjacent to the tumor, and normal tissue apart from the tumor were measured in 102 patients. Additionally, the PyNpase levels were measured in rat and mouse urinary bladders treated with BBN. RESULT: The PyNpase levels of tumor tissue significantly correlated to the tumor grade and growth pattern (papillary/non-papillary), while stage, multiplicity, and tumor shape (peduncle/sessile) were not independent factors. The low-risk tumor of primary, single, G1-Ta showed significantly low levels of PyNpase. The PyNpase levels in the tumor tissue were significantly higher than those in the normal tissue. The PyNpase levels in the adjacent normal tissue were significantly higher than those in the distant normal tissue. The PyNpase levels in rat bladder tissue were significantly higher in the BBN-treatment groups than in those in the control group, only during the early carcinogenic stage. The PyNpase levels in mouse bladder tissue were significantly higher in BBN-treatment groups than in those in the control group during the whole experiment period. CONCLUSION: Our results indicated that not only tumor tissue but also normal tissue adjacent to the tumor had a potential of angiogenesis for tumor development, and transurethral resection of the bladder tumor with a wide normal margin seems to be a reasonable strategy for decreasing the risk of recurrence.

Pyrimidine nucleoside phosphorylase and dihydropyrimidine dihydrogenase activities as predictive factors for the efficacy of doxifluridine together with mitomycin C as adjuvant chemotherapy in primary colorectal cancer.

BACKGROUND/AIMS: Pyrimidine Nucleoside Phosphorylase (PyNPase) converts 5'-deoxy-5-fluorouridine (5'-DFUR, doxifluridine) to 5-fluorouracil (5-FU). While this reaction is taking place Dihydropyrimidine Dihydrogenase (DPD) catalyzes 5-FU to inactive molecules. Mitomycin C (MMC) elevates the PyNPase level in tumor cells. METHODOLOGY: We investigated 17 colorectal cancer patients' PyNPase and DPD activities in tumor and normal tissues using an enzyme-linked immunosorbent assay (ELISA) to assess their clinical significance as indicators for selecting colorectal cancer patients for 5'-DFUR together with MMC as adjuvant chemotherapy. RESULTS: Six of 17 patients developed experienced a recurrence. Tumor DPD activity of the 6 patients who had a recurrence were higher than those of the 11 patients with no recurrence (p = 0.047). On the other hand, there were no significant differences in both the PyNPase and the PyNPase/DPD (P/D) ratio between the group with recurrence and the group without recurrence. For survival analyses, we designed the cut-off value of tumor PyNPase, DPD and P/D ratio as their median value and classified patients into a higher group and a lower group, but there were no significant differences between the groups. CONCLUSIONS: The DPD activity in the tumor may be a useful indicator for selecting patients likely respond to 5'-DFUR together with MMC as adjuvant chemotherapy. If tumor DPD is high, we had better select a different anticancer drug.

[Clinical significance of pyrimidine nucleoside phosphorylase (PyNPase) in breast cancer].

To clarify the clinical significance of pyrimidine nucleoside phosphorylase (PyNPase) activity in breast cancer, we examined the possible correlation of PyNPase activity to clinicopathological features and prognosis in twenty-one patients with primary breast cancer from April 2000 to December 2001. Flow signals of tumors were analyzed by Power Doppler sonography (PDUS), and maximal velocity (V(max)) was calculated. PyNPase activity of resected specimens was assayed by ELISA method. PyNPase activities in resected cancerous tissue were 156.9+/-63.5 unit/mg (mean+/-SD), which were significantly higher than that in normal tissue (19.0+/-18.1 unit/mg, p<0.0001). PyNPase activity was positively correlated with tumor size (r=0.496, p=0.026) and V(max) (r=0.498, p=0.021). The disease free survival rate was significantly lower in the high PyNPase activity group than in the low PyNPase activity group. In overall survival rate, there was no significant difference between the high and low PyNPase activity groups. In the multivariate analysis, PyNPase activity was an independent predictor of postoperative recurrence (p=0.032). We suggest that PyNPase activity is associated with progression and proliferation of breast cancer, and that it may be useful for prediction of the prognosis.

[A change of tumor PyNPase level at intraperitoneal and intravenous administrations of paclitaxel].

A level of PyNPase activity was measured after intraperitoneal (ip) and intravenous (i.v.) administrations of paclitaxel on the animal model. Nude mice received the subcutaneous implantation of WiDr cells. About 3 weeks later, the ip and i.v. administrations of paclitaxel were performed 2 times at 20 mg/kg and 15 mg/kg, respectively. About 1 week later, the mice were sacrificed. The level of PyNPase activity was measured by the ELISA method. The level of PyNPase of ip and i.v. was higher than that of the control group, but the level of PyNPase revealed no significant difference between ip and i.v.. This result suggested that intraperitoneal administration of paclitaxel enhanced an efficiency of 5'-DFUR and capecitabine as much as intravenous administration of paclitaxel.

[Clinicopathological significance of pyrimidine nucleoside phosphorylase (PyNPase) and dihydropyrimidine dehydrogenase (DPD) in advanced colorectal cancer].

We examined clinicopathological characteristics and prognoses of seventy advanced colorectal cancer cases by measuring pyrimidine nucleoside phosphorylase (PyNPase) and dihydropyrimidine dehydrogenase (DPD) in tumor and normal tissue. PyNPase activities in cancerous tissue obtained from resected were 82.7 +/- 41.9 U/mg protein, which were significantly higher than 37.2 +/- 24.0 U/mg protein in normal tissue (p < 0.001). On the other hand, DPD activities in cancerous tissue were significantly lower in normal tissue (p < 0.05). In cases with lymphnode metastases, PyNPase activities of cancerous tissue were significantly higher than that of no lymphnode metastases cases (p < 0.05). In cases with grade 2 side-effects or higher by oral adjuvant chemotherapy, DPD activities in normal tissue were significantly lower than that of other cases (p < 0.05). With regard to Dukes' B and C cases that were resected curatively, PyNPase activities of cancerous tissue of higher group's prognosis were worse than that of the lower group. In the group received 5'-DFUR as adjuvant chemotherapy, non-recurrent survival rate of the group exhibiting higher PyNPase activities was better than that of the lower group.

Advanced gastric cancer with peritoneal dissemination successfully treated with paclitaxel and doxifluridine: a case report.

A 50-year-old female presenting with severe ascites and anemia and diagnosed with advanced gastric cancer was admitted to our hospital. Endoscopic examination revealed an edematous lesion with redness and a giant fold in the stomach with poor expansion. The histological examination of biopsy specimens from the edematous lesion revealed signet-ring-cell carcinoma. Computed tomography demonstrated a thickening of the gastric wall, severe ascites, and peritoneal dissemination in the Douglas pouch. Paclitaxel (70mg/m2) was administered to the patient on days 1, 8, and 15, with doxifluridine (533mg/m2) for five days per week, on a 28-day cycle. By completion of the first course of treatment, the ascites had disappeared, the tumor in the Douglas pouch had shrunk, and the thickening of the gastric wall had lessened. In addition, the fold in the stomach appeared by endoscopic examination to have resumed its normal thickness, no malignant cells were detected in a biopsy, and the thymidine phosphorylase activity in the tumor tissue was two-fold greater than that before chemotherapy. After three treatment courses, the number of apoptotic cells had apparently increased compared with the prechemotherapy number. The only adverse drug reactions that were observed were grade 2 alopecia and grade 1 myalgia. After thirteen courses of chemotherapy over the past one year, both primary and metastatic lesions seem to be regressing. This case study suggests that paclitaxel plus doxifluridine therapy is effective and well-tolerated in non-resectable gastric cancer patients.

High level concentration of pyrimidine nucleoside phosphorylase in esophageal squamous cell carcinoma but no correlation with clinicopathological parameters.

Pyrimidine nucleoside phosphorylase (PyNPase) converts 5'-deoxy-5-fluorouridine to 5'-fluorouracil, which exerts an anticancer effect before being catabolized by dihydropyrimidine dehydrogenase (DPD). Recently, PyNPase has been shown to be identical to a potent angiogenic factor, platelet-derived endothelial cell growth factor. We analyzed the concentration of PyNPase and DPD in 33 patients with esophageal squamous cell carcinoma in fresh-frozen samples by enzyme-linked immunosorbent assay. In addition, we evaluated the clinical significance and prognostic value of PyNPase expression in esophageal carcinoma. The PyNPase concentration of tumor tissue was statistically higher than that of normal tissue of the esophagus (248 +/- 146 U/mg protein vs 73 +/- 63 U/mg protein, P = 0.0001), whereas DPD showed no difference (90 +/- 62 U/mg protein vs 88 +/- 62 U/mg protein, P = 0.825). The ratio of PyNPase to DPD of tumor tissue was statistically higher than that of normal tissue of the esophagus (3.3 vs 0.95, P = 0.0001). There were no significant differences between the group with high tumor to normal tissue ratios of PyNPase concentration and the low-ratio group in terms of the tumor length, depth, lymph node metastasis, lymph vessel invasion, vascular invasion, stage and survival. In conclusion, 5'-deoxy-5-fluorouridine may be effective on esophageal carcinoma and PyNPase concentration in esophageal carcinoma may not be a useful prognostic marker for patients with esophageal squamous cell carcinoma.

[PyNPase and DPD expression potentially predict response to 5'-DFUR treatment for node-positive breast cancer patients].

Pyrimidine nucleoside phosphorylase (PyNPase) and dihydropyrimidine dehydrogenase (DPD) activity may be related of the antitumor effect of 5'-deoxy-5-fluorouridine (5'-DFUR). To select patients for adjuvant setting of 5'-DFUR, we assessed PyNPase and DPD activity in 41 primary tumors (PTs) and 227 lymph nodes (LNs) of breast cancer patients. Fifty-one patients were involved in this investigation (mean age 54 +/- 12 years). LN metastasis was positive in 23 cases (node-positive group). Metastatic cancer cells were positive in 65 lymph nodes (In + group). PyNPase and DPD activity were measured by ELISA. PyNPase activity in PTs of the node-positive group was significantly higher than in the node-negative group. PyNPase activity in LNs of In + group was also significantly higher than in the negative metastatic cancer cell group. However, no significant differences were noted between these groups in DPD activity. PyNPase/DPD ratio in LNs of the In + group was marginally higher than in the negative metastatic cancer cell group. These data suggest that 5'-DFUR is preferably sensitive in breast cancer patients with lymph node metastasis.