The correlation of thymidine phosphorylase activity with the expression of interleukin 1 alpha, interferon alpha and interferon gamma in human colorectal carcinoma

Interleukin-1 receptor antagonist: An alternative therapy for cancer treatment

The interleukin-1 receptor antagonist (IL-1Ra) is an anti-inflammatory cytokine and a naturally occurring antagonist of the IL-1 receptor. It effectively counteracts the IL-1 signaling pathway mediated by IL-1α/β. Over the past few decades, accumulating evidence has suggested that IL-1 signaling plays an essential role in tumor formation, growth, and metastasis. Significantly, anakinra, the first United States Food and Drug Administration (FDA)-approved IL-1Ra drug, has demonstrated promising antitumor effects in animal studies. Numerous clinical trials have subsequently incorporated anakinra into their cancer treatment protocols. In this review, we comprehensively discuss the research progress on the role of IL-1 in tumors and summarize the significant contribution of IL-1Ra (anakinra) to tumor immunity. Additionally, we analyze the potential value of IL-1Ra as a biomarker from a clinical perspective. This review is aimed to highlight the important link between inflammation and cancer and provide potential drug targets for future cancer therapy.

IL-1α and colorectal cancer pathogenesis: Enthralling candidate for anti-cancer therapy

Inflammation has been well-established as a hallmark of colorectal cancer (CRC). Interleukin-1 alpha (IL-1α) is one of the primary inflammatory mediators driving the pathogenesis of inflammation-associated CRC. This systematic review presents the roles of IL-1α in the pathogenesis of the disease. Bibliographic databases PubMed, Science Direct, Scopus and Web of Science were systematically searched for articles that addresses the relationship between IL-1α and colorectal cancer. We highlighted various mechanisms by which IL-1α promotes the pathogenesis of CRC including enhancement of angiogenesis, metastasis, resistance to therapy, and inhibition of tumour suppressive genes. We also discussed the potential mechanisms by which IL-1α expression is induced or secreted in various studies. Beyond these, the systematic review also highlights several potential therapeutic strategies which should be further explored in the future; to target IL-1α and/or its associated pathways; paving our way in finding effective treatments for CRC patients.

Enhanced interferon signaling pathway in oral cancer revealed by quantitative proteome analysis of microdissected specimens using 16O/18O labeling and integrated two-dimensional LC-ESI-MALDI tandem MS

Oral squamous cell carcinoma (OSCC) remains one of the most common cancers worldwide, and the mortality rate of this disease has increased in recent years. No molecular markers are available to assist with the early detection and therapeutic evaluation of OSCC; thus, identification of differentially expressed proteins may assist with the detection of potential disease markers and shed light on the molecular mechanisms of OSCC pathogenesis. We performed a multidimensional (16)O/(18)O proteomics analysis using an integrated ESI-ion trap and MALDI-TOF/TOF MS system and a computational data analysis pipeline to identify proteins that are differentially expressed in microdissected OSCC tumor cells relative to adjacent non-tumor epithelia. We identified 1233 unique proteins in microdissected oral squamous epithelia obtained from three pairs of OSCC specimens with a false discovery rate of <3%. Among these, 977 proteins were quantified between tumor and non-tumor cells. Our data revealed 80 dysregulated proteins (53 up-regulated and 27 down-regulated) when a 2.5-fold change was used as the threshold. Immunohistochemical staining and Western blot analyses were performed to confirm the overexpression of 12 up-regulated proteins in OSCC tissues. When the biological roles of 80 differentially expressed proteins were assessed via MetaCore analysis, the interferon (IFN) signaling pathway emerged as one of the most significantly altered pathways in OSCC. As many as 20% (10 of 53) of the up-regulated proteins belonged to the IFN-stimulated gene (ISG) family, including ubiquitin cross-reactive protein (UCRP)/ISG15. Using head-and-neck cancer tissue microarrays, we determined that UCRP is overexpressed in the majority of cheek and tongue cancers and in several cases of larynx cancer. In addition, we found that IFN-beta stimulates UCRP expression in oral cancer cells and enhances their motility in vitro. Our findings shed new light on OSCC pathogenesis and provide a basis for the future development of novel biomarkers.

Single Ascending Dose Tolerability, Pharmacokinetic–Pharmacodynamic Study of Dihydropyrimidine Dehydrogenase Inhibitor Ro 09-4889

PURPOSE

Ro 09-4889 was designed to enhance the anticancer efficacy of capecitabine (Xeloda) by generating a dihydropyrimidine dehydrogenase inhibitor (DPDi) 5-vinyluracil (5-VU) preferentially in tumor tissues. This study assessed the tolerance to Ro 09-4889 treatment, and related pharmacokinetic and pharmacodynamic data such as inhibition of DPD activity in peripheral blood mononuclear cells (PBMCs) and plasma uracil levels.

EXPERIMENTAL DESIGN

This was a single-center, double-blind, placebo-controlled, single-dose escalation study in 64 healthy male volunteers at 1-, 5-, 20-, 50-, 75-, 100-, and 200-mg oral dose of Ro 09-4889. Also, food effect was assessed separately in a group dosed with 20 mg of the compound.

RESULTS

No serious adverse effects or significant laboratory and electrocardiogram abnormalities were observed during the study. Ro 09-4889 has a short elimination half-life (t(1/2)) of 0.5 h, followed by metabolites 5'-deoxy-5-vinyluridine (5'-DVUR), 5'-deoxy-5-vinylcytidine (5'-DVCR), and 5-VU with t(1/2) of 1.3, 1.2, and 2 h, respectively. The major metabolite excreted in urine was 5-DVCR (45% of dose). The inhibition of PBMC DPD activity and the increase in plasma uracil were related to Ro 09-4889 dose. DPD inhibition versus dose and uracil AUC (area under the curve) versus dose were modeled using the E(max) model with a baseline effect. The model-predicted ED(50) value was 100 mg.

CONCLUSION

Single oral doses of Ro 09-4889 ranging from 1 to 200 mg were well tolerated. On the basis of these findings, a 10-to-30-mg dose range of Ro 09-4889 combined with capecitabine could be appropriate for further evaluation in cancer patients.

The Sp1 transcription factor contributes to the tumor necrosis factor-induced expression of the angiogenic factor thymidine phosphorylase in human colon carcinoma cells

Thymidine phosphorylase (TP; also known as platelet-derived endothelial cell growth factor, PD-ECGF) is an angiogenic factor that is chemotactic for endothelial cells and has been found to induce neovascularization in vivo. TP is frequently overexpressed in human solid tumors, where its expression has been correlated with increased tumor microvessel density, invasion, and metastasis, and shorter patient survival. In this report, TP activity in the WiDr colon carcinoma cell line was found to be induced 100-fold by tumor necrosis factor (TNFalpha), a secretory product of activated macrophages that has indirect angiogenic activities. Increased TP activity was accompanied by increased TP mRNA levels and without an increase in mRNA stability. TNFalpha-induced TP mRNA levels were reduced by mithramycin, a DNA-binding transcription inhibitor specific for GC-rich sequences. Transcriptional regulation by TNFalpha was confirmed by transient transfection of WiDr with upstream TP sequences in a luciferase reporter construct. Deletion analysis of the reporter pinpointed two regions of the TP promoter with regulatory elements for both TNFalpha-inducible and basal expression, and they contained, respectively, three and one consensus binding sites for the Sp1-family of transcription factors. One additional region contributed only to basal TP expression, and it contained three Sp1 sites. TNFalpha-induced TP expression decreased when point mutations were made in three of the four Sp1 sites postulated to contribute to both basal and TNFalpha-inducible expression. Electrophoretic mobility shift assays further demonstrated binding of nuclear Sp1 to these three sites. Sp1-binding activity was also increased in cells treated with TNFalpha. These studies establish a role for Sp1 in the regulation of expression of the angiogenic factor TP in colon cancer WiDr cells.

Expression of uridine and thymidine phosphorylase genes in human breast carcinoma

Uridine phosphorylase (UPase) and an angiogenic enzyme, thymidine phosphorylase (dThdPase) are involved in degradation of the pyrimidine nucleosides through phosphorolysis. The expression levels of UPase and dThdPase are higher in human solid tumors including breast carcinomas than in normal tissues. To clarify the correlation between the expression levels of UPase and dThdPase genes and the clinicopathological factors, mRNA levels of these enzymes were examined by RT-PCR in 43 breast carcinomas. UPase gene expression was not correlated with dThdPase gene expression (regression coefficient R = 0.032). Although the expression level of the dThdPase gene was correlated with angiogenesis, detected by immunostaining endothelial cells (R = 0.66), that of UPase gene was not (R = 0.044). These results suggest that UPase does not have a strong angiogenic activity. The UPase gene expression levels in tumors of patients who relapsed were significantly higher than in those from patients who did not (p = 0.039). Although the expression levels of neither UPase or dThdPase were associated with age, pT, pN, pM, estrogen or progesterone receptor positivity, the patients with the higher levels of UPase gene expression had worse survival (p = 0.0038) than those with lower levels. In contrast, the expression of dThdPase gene was not related to relapse or survival of these patients with breast carcinoma. Our findings suggest that the expression level of UPase gene may be an independent prognostic marker in human breast carcinoma.

Structural analyses reveal two distinct families of nucleoside phosphorylases

The reversible phosphorolysis of purine and pyrimidine nucleosides is an important biochemical reaction in the salvage pathway, which provides an alternative to the de novo purine and pyrimidine biosynthetic pathways. Structural studies in our laboratory and by others have revealed that only two folds exist that catalyse the phosphorolysis of all nucleosides, and provide the basis for defining two families of nucleoside phosphorylases. The first family (nucleoside phosphorylase-I) includes enzymes that share a common single-domain subunit, with either a trimeric or a hexameric quaternary structure, and accept a range of both purine and pyrimidine nucleoside substrates. Despite differences in substrate specificity, amino acid sequence and quaternary structure, all members of this family share a characteristic subunit topology. We have also carried out a sequence motif study that identified regions of the common subunit fold that are functionally significant in differentiating the various members of the nucleoside phosphorylase-I family. Although the substrate-binding sites are arranged similarly for all members of the nucleoside phosphorylase-I family, a comparison of the active sites from the known structures of this family indicates significant differences between the trimeric and hexameric family members. Sequence comparisons also suggest structural identity between the nucleoside phosphorylase-I family and both 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase and AMP nucleosidase. Members of the second family of nucleoside phosphorylases (nucleoside phosphorylase-II) share a common two-domain subunit fold and a dimeric quaternary structure, share a significant level of sequence identity (>30%) and are specific for pyrimidine nucleosides. Members of this second family accept both thymidine and uridine substrates in lower organisms, but are specific for thymidine in mammals and other higher organisms. A possible relationship between nucleoside phosphorylase-II and anthranilate phosphoribosyltransferase has been identified through sequence comparisons. Initial studies in our laboratory suggested that members of the nucleoside phosphorylase-II family require significant domain movements in order for catalysis to proceed. A series of recent structures has confirmed our hypothesis and provided details of these conformational changes. Structural studies of the nucleoside phosphorylases have resulted in a wealth of information that begins to address fundamental biological questions, such as how Nature makes use of the intricate relationships between structure and function, and how biological processes have evolved over time. In addition, the therapeutic potential of suppressing the nucleoside phosphorylase activity in either family of enzymes has motivated efforts to design potent inhibitors. Several research groups have synthesized a variety of nucleoside phosphorylase inhibitors that are at various stages of preclinical and clinical evaluation.

Angiogenic effect of thymidine phosphorylase on macrophages in glioblastoma multiforme

OBJECT

Thymidine phosphorylase (TP) and vascular endothelial growth factor (VEGF) are known angiogenic factors; however, there are few reports in which the relationship between these two factors is addressed. The authors compared expression patterns of TP and VEGF and investigated their role in the angiogenesis of glioblastoma multiforme (GBM).

METHODS

Surgical specimens from 41 cases of GBM were immunohistochemically stained for TP, VEGF, CD68 (a macrophage marker), and CD31 (an endothelial cell marker). Both TP labeling indices and VEGF immunoreactivity displayed significant correlations with vascular density. Although VEGF was diffusely distributed in the tumor, TP was strongly expressed around blood vessels and in vascular proliferation. Double labeling for TP and CD68 in 10 cases indicated that cells that reacted strongly positive for TP were almost always macrophages, and only small numbers of CD68-negative cells weakly expressed TP. The TP messenger (m)RNA expression was investigated using reverse transcription-polymerase chain reaction in six GBMs. All six specimens expressed TP mRNA. In addition, TP mRNA was detected in two of three groups of cultured GBM cells derived from surgical specimens. Macrophages, the production of which was induced from two volunteers' peripheral blood monocytes by applying macrophage colony-stimulating factor, also expressed TP mRNA. The glioma cell lines U251MG and U87MG, which barely express TP mRNA under normal conditions, expressed TP mRNA in response to interferon-beta stimulation or while in an anoxic condition.

CONCLUSIONS

Although it is feasible that GBM cells can express TP depending on their growing conditions, the majority of TP-expressing cells present in GBMs appear to be infiltrating macrophages. Coexistence of VEGF and TP may indicate a synergistic upregulation for angiogenesis because VEGF exerts a chemotactic activity on macrophages that express TP.

Significant correlation between expression of interleukin-1alpha and liver metastasis in gastric carcinoma

BACKGROUND

Interleukin (IL)-1 has been reported to augment the hematogeneous metastasis of some cancers by inducing the expression of adhesion molecules on vascular endothelial cells and also increasing the expression of proteases from tumor cells in vitro. The purpose of this study was to determine the clinical significance of the IL-1alpha expression in primary tumors of gastric carcinoma.

METHODS

Paraffin embedded sections of the tumors obtained from 109 patients who underwent a gastrectomy for gastric carcinoma with subserosal invasion were stained for IL-1alpha by using the streptavidin biotin method. Staining was considered positive when 10% or more of the malignant cells displayed cytoplasmic staining.

RESULTS

Sixty (55.0%) tumors expressed IL-1alpha. Positive staining for IL-1alpha was more likely in patients with differentiated tumors than in those with undifferentiated tumors. The expression of IL-1alpha showed a significant correlation with liver metastasis. Of the 84 patients receiving a curative resection, those with tumors expressing IL-1alpha had a significantly higher incidence of liver recurrence than those without. A logistic regression analysis revealed positive staining for IL-1alpha to be the best predictive factor of patients who develop liver recurrence.

CONCLUSIONS

The authors' results suggest that the immunohistochemical expression of IL-1alpha is a useful predictor of liver recurrence in patients undergoing a curative resection for gastric carcinoma with subserosal invasion.

Co-expression of thymidine phosphorylase and heme oxygenase-1 in macrophages in human malignant vertical growth melanomas

Expression of thymidine phosphorylase (TP) is often associated with tumor angiogenesis and / or prognosis in patients. Further, infiltration of macrophages is closely correlated with the depth of tumor and angiogenesis in melanomas. In this study, we examined the expression of TP and an activated macrophage-specific enzyme, heme oxygenase-1 (HO-1), involved in malignancy in 22 cases with melanomas. TP was strongly expressed not only in CD68-positive macrophages in and around tumors, but also in S100 protein-positive melanoma cells, fibroblasts and keratinocytes. By contrast, HO-1 was specifically expressed in macrophages, but only slightly in melanoma cells and other cell types in the stroma of melanomas. We thus observed apparent co-expression of TP and HO-1 in macrophages infiltrating in the late stage of malignant melanomas. There appeared increasing numbers of TP-positive cells in Clark level IV and V melanoma compared with Clark level I (in situ) melanoma, and there was also a close correlation between numbers of TP-positive cells and HO-1-positive cells. Both TP- and HO-1-positive macrophages could be observed in the stroma in and around tumors in vertical growth melanomas.

Significance of thymidine phosphorylase/platelet-derived endothelial cell growth factor in carcinoma of the papilla of Vater

The expression of thymidine phosphorylase (TP) in carcinoma of the papilla of Vater was studied to clarify its significance in tumor progression and in determining prognosis. Fifty-nine cases of surgically resected carcinoma of the papilla of Vater were studied. Immunohistochemical staining was performed to evaluate the expression of TP, microvessel count and p53 overexpression. TP expression was demonstrated in tumor cells in 62.7% (37/59) of the cases. A higher frequency of regional lymph node metastasis was found in TP-positive tumors than in TP-negative tumors (P = 0.006). TP-positive tumors were more advanced than TP-negative tumors with regard to clinical stage (P = 0.035). TP-positive tumors had significantly higher microvessel density (27.6 +/- 10.1) than TP-negative tumors (20.4 +/- 10.0, P = 0.01). Moreover, TP expression was significantly correlated with a poor prognosis (P = 0. 02). These suggest that in carcinoma of the papilla of Vater, TP production by tumor cells is correlated with tumor progression through its regulatory effect on neovascularization.

Thymidine phosphorylase: its role in sensitivity and resistance to anticancer drugs

Thymidine phosphorylase (TP) is an angiogenic enzyme present in normal tissues. Increased levels are found in many tumors, in stromal cells, tumor cells or both. High tumor TP levels may confer a poor prognosis. Cytokines (including interferons), tissue hypoxia and low pH increase TP levels. The influence of tumor TP on fluoropyrimidine toxicity is variable, but capecitabine is a prodrug of fluorouracil that requires activation by TP and hence may have a higher therapeutic index than other fluoropyrimidines. Folate-based thymidylate synthase inhibitors may also be more effective in tumors with a high TP because of increased degradation of endogenous thymidine. Copyright 1999 Harcourt Publishers Ltd.

The crystal structure of pyrimidine nucleoside phosphorylase in a closed conformation

BACKGROUND

Pyrimidine nucleoside phosphorylase (PYNP) catalyzes the reversible phosphorolysis of pyrimidines in the nucleotide synthesis salvage pathway. In lower organisms (e.g. Bacillus stearothermophilus) PYNP accepts both thymidine and uridine, whereas in mammalian and other higher organisms it is specific for thymidine (designated thymidine phosphorylase, TP). PYNP shares 40% sequence similarity (and presumably significant structural similarity) with human TP, which has been implicated as a growth factor in tumor angiogenesis. It is thought that TP undergoes a major conformational change upon substrate binding that consequently produces an active conformation.

RESULTS

The crystal structure of PYNP from B. stearothermophilus with the substrate analog pseudouridine in its active site has been solved to 2.1 A resolution. This structure confirms the similarity of PYNP to TP and supports the idea of a closed active conformation, which is the result of rigid body movement of the alpha and alpha/beta domains. The active-site cleft, where the pyrimidine and phosphate substrates bind, is between the two domains. The structure reveals an asymmetric dimer in which one subunit is fully closed and the other is only partially closed.

CONCLUSIONS

The closed conformation of PYNP serves as a good model to better understand the domain movement and overall function of TP. Active-site residues are confirmed and a possible mechanism for substrate binding and subsequent domain movement is suggested. Potent inhibitors of TP might have significant therapeutic value in various chemotherapeutic strategies, and the structure of PYNP should provide valuable insight into the rational design of such inhibitors.

Structural and theoretical studies suggest domain movement produces an active conformation of thymidine phosphorylase

Two new crystal forms of Escherichia coli thymidine phosphorylase (EC 2.4.2.4) have been found; a monoclinic form (space group P21) and an orthorhombic form (space group I222). These structures have been solved and compared to the previously determined tetragonal form (space group P43212). This comparison provides evidence of domain movement of the alpha (residues 1 to 65, 163 to 193) and alpha/beta (residues 80 to 154, 197 to 440) domains, which is thought to be critical for enzymatic activity by closing the active site cleft. Three hinge regions apparently allow the alpha and alpha/beta-domains to move relative to each other. The monoclinic model is the most open of the three models while the tetragonal model is the most closed. Phosphate binding induces formation of a hydrogen bond between His119 and Gly208, which helps to order the 115 to 120 loop that is disordered prior to phosphate binding. The formation of this hydrogen bond also appears to play a key role in the domain movement. The alpha-domain moves as a rigid body, while the alpha/beta-domain has some non-rigid body movement that is associated with the formation of the His119-Gly208 hydrogen bond. The 8 A distance between the two substrates reported for the tetragonal form indicates that it is probably not in an active conformation. However, the structural data for these two new crystal forms suggest that closing the interdomain cleft around the substrates may generate a functional active site. Molecular modeling and dynamics simulation techniques have been used to generate a hypothetical closed conformation of the enzyme. Analysis of this model suggests several residues of possible catalytic importance. The model explains observed kinetic results and satisfies requirements for efficient enzyme catalysis, most notably through the exclusion of water from the enzyme's active site.

Thymidine phosphorylase (platelet-derived endothelial cell growth factor), microvessel density and clinical outcome in hepatocellular carcinoma

BACKGROUND/AIMS

Angiogenesis plays an important role in tumor growth and metastasis. It is regulated by angiogenic factors. Thymidine phosphorylase (platelet-derived endothelial cell growth factor) is one such factor. Although the significance of platelet-derived endothelial cell growth factor has been studied for several types of tumor, the expression of platelet-derived endothelial cell growth factor and its correlation with microvessel density or clinicopathological factors in hepatocellular carcinoma are unknown. We evaluated microvessel density and platelet-derived endothelial cell growth factor expression in hepatocellular carcinoma to determine whether microvessel density and platelet-derived endothelial cell growth factor expression are correlated with the clinicopathological factors of hepatocellular carcinoma.

METHODS

Using immunohistochemical staining with anti-platelet-derived endothelial cell growth factor antibody and the ELISA method, we evaluated the correlation among platelet-derived endothelial cell growth factor expression, microvessel density and clinicopathological factors in 84 hepatocellular carcinoma patients. Microvessels were stained with anti-human von Willebrand factor (anti-Factor VIII) and anti-CD34.

RESULTS

In the surrounding liver, there was a significant correlation between microvessel density and platelet-derived endothelial cell growth factor expression (p=0.002), and hepatitis C virus-positive livers had higher microvessel densities than otherwise (p=0.003). However, this correlation was not found for hepatocellular carcinoma, but hepatitis C virus-positive tumors had higher expression of platelet-derived endothelial cell growth factor (p=0.018). Microvessel density in hepatocellular carcinoma obtained by Factor VIII staining inversely affected the recurrence-free survival rate (p=0.0416), but the microvessel density by CD34 staining was not a significant predictor.

CONCLUSIONS

This study indicates that platelet-derived endothelial cell growth factor may not be a major regulator of angiogenesis of hepatocellular carcinoma, but this enzyme may play an important role in hepatocarcinogenesis cooperating with hepatitis C virus. Also, the density, not of sinusoid-like vessels, but of larger vessels in hepatocellular carcinoma could be a prognostic factor for hepatocellular carcinoma.

Extracellular matrix remodelling in a murine mammary adenocarcinoma transfected with the interferon-alpha 1 gene

The rejection of interferon alpha 1 gene-transfected mammary adenocarcinoma cells (TSA-IFN alpha) injected into syngeneic BALB/c mice was accompanied by an unusual stromal reaction and marked CD8-positive T-lymphocyte involvement. To investigate the biological background of this reaction, the possibility was evaluated that an interaction between TSA-IFN alpha and stromal cells might remodel the extracellular matrix (EM). When fibroblasts were co-cultured with TSA-IFN alpha or treated with exogenous IFN alpha, there was no change in their replication rate or collagen synthesis. By contrast, their fibronectin (FN) production and release were increased, resulting in enhanced fibroblast chemotaxis. These findings were mirrored by increased FN staining in the peritumoural and tumoural areas in vivo. IFN alpha thus determines increased FN production and hence massive local recruitment and activation of fibroblasts, with a modification of the EM. The several activities of IFN alpha should thus be considered prior to its employment in clinical trials.