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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metastases in rat liver were generated experimentally by intraportal injection of colon cancer cells to investigate the effects of cancerous growth on the metabolism of surrounding liver tissue. Maximum activities (capacity) of glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, lactate dehydrogenase, succinate dehydrogenase, alkaline phosphatase, 5'-nucleotidase, xanthine oxidoreductase, purine nucleoside phosphorylase and adenosine triphosphatase have been determined. Two types of metastases were found, a small type surrounded by stroma and a larger type in direct contact with hepatocytes. Both types affected the adjacent tissue in a similar way suggesting that the interactions were not mediated by stroma. High capacity of the degradation pathway of extracellular purines released from dead cells of either tumours or host tissue was found in stroma and sinusoidal cells. Metastases induced both an increase in the number of Kupffer cells and proliferation of hepatocytes. The distribution pattern in the liver lobulus of most enzymes investigated did not change distinctly. However, activity of alkaline phosphatase, succinate dehydrogenase and phosphogluconate dehydrogenase was increased in hepatocytes directly surrounding metastases. These data imply that the overall metabolic zonation in liver lobuli is not dramatically disturbed by the presence of cancer cells despite the fact that various metabolic processes in liver cells are affected.
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PMID:Experimentally induced colon cancer metastases in rat liver increase the proliferation rate and capacity for purine catabolism in liver cells. 822 8

Lymphatic spread of colorectal cancer cells to regional lymph nodes is one of the early events in metastatic cancer, and is often associated with distant metastatic spread and a poor prognosis. This study examined lymphangiogenic factors, and in particular a panel of newly discovered lymphangiogenic markers, in colorectal cancer tissues from a cohort of patients. Paired samples (background normal mucosa and cancer) of colon tissue were obtained from patients with colorectal cancer. The expression and levels of the VEGF-C and VEGF-D cytokines, the VEGF receptors VEGFR-2 and VEGFR-3, and newly described lymphatic endothelial markers, LYVE-1, Prox-1, podoplanin and 5'-nucleotidase were assessed. RNA was extracted from the frozen colon tissues. The level of expression for each factor/marker was determined using RT-PCR and quantified using a real-time quantitative PCR (RT-QPCR) technique, with respective cloned cDNA plasmids as internal standards. VEGF-D was expressed to a significantly higher degree in the colon tumour tissues. There was no significant difference between the expression levels for both VEGF-C and its receptor, VEGFR-2, in background and cancer tissues. However, levels of the VEGFR-3 receptor were found to be significantly higher in colon cancer than the normal background tissues. LYVE-1 levels were below detection in most cases. There was a significant increase in the degree of Prox-1 and 5'-nucleotidase expression in colon cancer tissue. Podoplanin expression was also increased in the cancer samples. These markers indicate an increase in lymphangiogenesis in colon cancer, and may therefore have prognostic value for colon cancer patients.
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PMID:Quantitative analysis of lymphangiogenic markers in human colorectal cancer. 1285 6

We studied nitric oxide (NO) production, adenosine deaminase (ADA) and 5'-nucleotidase (5-N) activity as a function of macrophage activation in the model of spontaneous metastasis of ESbL T lymphoma cells transduced with the lacZ gene. Liver and spleen macrophages were isolated and examined directly ex vivo without further experimental manipulation. Transient arrest of liver metastasis was accompanied by an increase of NO production and ADA activity and by a decrease of 5-N activity. An aggressive expansion of metastasis was correlated with a drop of NO production and ADA activity and with an increase of 5-N activity. To test the involvement of in situ activated Kupffer cells in an antimetastatic response, two immunotherapy protocols were used: i) active immunization with lymphoma cells and ii) adoptive transfer of antitumor immune spleen cells. Both treatments caused an upregulation of ADA activity and NO production in Kupffer cells, which correlated with host resistance against metastases.
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PMID:In-situ activated macrophages are involved in host-resistance to lymphoma metastasis by production of nitric-oxide. 2155 2

The karyotypes of human melanomas exhibit multiple chromosome alterations. Recurrent deletions of 9p, 10q and 14q arms, which carry genes encoding for enzymes of purine metabolism, were also found in human gliomas, another neuroectodermal tumor previously studied for both cytogenetics and nucleotides metabolism. Postulating that this metabolism might also be modified in melanomas, the activities of eleven enzymes involved in catabolic and synthetic pathways of purine metabolism were measured, in addition to two enzymes of the pyrimidine synthesis. Assays were performed on six melanoma mestastases, five nodal and one cutaneous, after transplantation into nude mice. The purine metabolism was characterized by a more active catabolic than synthetic pathway, a possible imbalance between de novo and salvage pathways for adenylates synthesis, rather in favor of the de novo pathway, and a more active adenylate than guanylate synthesis. The skin metastasis exhibited quite different cytogenetic and metabolic patterns, when compared to the nodal metastases. Considering the relationships between cytogenetic and metabolic data, low activities of methylthioadenosine phosphorylase, adenosine kinase, adenosine monophosphate deaminase, nucleoside phosphorylase and 5'-nucleotidase were observed in melanomas, as well as frequent losses of 9p, 10q, Ip, 14q and 6q arms respectively carrying genes encoding for these enzymes, most of these rearrangements were confirmed by chromosome painting. The two enzymes exhibiting the highest activities were adenosine deaminase and adenylosuccinate lyase, encoded by genes mapped on chromosomes 20 and 22 respectively, frequently in excess in melanomas. Thus, for these tumors, the metabolic pattern roughly parallels the cytogenetic profile, even if the absence of case to case correlation suggests that gene dosage effect, if it occurs, is not the only parameter involved. The main enzymatic and cytogenetic difference between melanomas and gliomas, concerns both adenylosuccinate lyase activity and the balance of chromosome 22, high in melanomas and low in gliomas.
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PMID:Nucleotide-metabolism and chromosome alterations in human-malignant melanoma xenografts. 2155 73


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