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

Many cancers display characteristic organ colonization patterns that do not fit simple, anatomical-mechanical trapping theories of tumor cell dissemination. Organ preferences of metastatic spread appear to be mediated partly by the selective attachment of tumor cells to organ-specific, microvascular endothelium. To study these tumor cell-endothelial cell interactions in an efficient and reproducible manner, we have designed a novel in vitro assay system wherein endothelial cells isolated from large vessels (e.g., aorta) can be modulated to assume phenotypic traits of organ-specific, microvascular endothelium. Modulation is achieved by growing bovine aortic endothelial cells (BAEC) on organ-specific matrix components, termed tumor attachment modulators (TAMs). Using monolayers of modulated BAEC in a tumor attachment assay, we show here that tumor cells which metastasize to a given organ, have a significantly higher binding affinity for BAEC grown on TAMs of the preferred, metastasized organ, than they have for BAEC grown on TAMs of any other organ not colonized by these tumor cells. Lung-metastatic tumor cells (R3230AC-MET, B16-F10) adhere preferentially to BAEC monolayers grown on lung-specific TAMs, whereas liver-metastatic tumor cells (RAW117-H10, M5076) selectively adhere to BAEC grown on liver-specific TAMs. In contrast, nonmetastatic tumors cells (R3230AC-LR, RBTCC-1, 647V) show no such adhesion preferences. Preferential tumor cell adherence is increased by growing BAEC for prolonged periods on organ-specific TAMs. Metastatic preference and organ distribution are mediated, at least in part, by urea-extractable endothelial cell surface components that are regulated by the extracellular matrix.
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PMID:Organ preference of metastasis. The role of organ-specifically modulated endothelial cells. 335 32

To demonstrate that the anorexia and depletion of cachexia reverses on tumor removal, F344 rats underwent sarcoma resection when their food intake fell to 0 g/day. In survivors of surgery, reversal in food intake was apparent within 3 days postoperatively, followed after 2 days by gain in host weight. To detect whether the transmission of anorexia/cachexia in these tumor-bearing (TB) rats was via the circulation, four groups were studied: single non-tumor bearing (NTB); single TB; parabiotic NTB; and parabiotic TB. The measured blood exchange rate between parabiotic halves was 1.2-1.5%/min. No cachectic effect was detected in either half of the NTB parabionts. There was no evidence of sarcoma metastases in the tumor-free half of the parabiotic TB pair. All the rats associated with the presence of tumor showed cachectic effects but the degree and timing of effect varied among the three conditions, single TB, parabiotic TB half, and parabiotic tumor-free half. In all variables examined (fall in food intake, time of first fall in food intake, host weight loss, elevation of blood urea nitrogen) the severities were always in the same sequence: single TB greater than parabiotic TB half greater than parabiotic tumor-free half greater than NTB. In addition, the TB parabiotic pair had a significantly longer survival time and grew a significantly larger tumor than did the single TB animal. The parabiotic tumor had a slower initial growth rate and a slower deceleration rate than the singlet tumor. These results provide evidence for the humoral mediation of cancer-associated cachexia.
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PMID:Parabiotic transfer of cancer anorexia/cachexia in male rats. 386 7

Because more than 80% of all cancer deaths are caused by metastases, development and evaluation of methods for fighting tumor dissemination should be major tasks of present cancer research. Formation of metastases is favoured by both reduced numbers of immune cells in the bloodstream and impaired oxygen transport into tissues. These closely related signs often emerge concomitantly when the organism is endangered by circulating tumor cells released from the original tumor by therapeutic manipulations. From knowledge of these facts the O2-multistep immunostimulation technique has been developed as a way of diminishing the risk of tumor spread. The process combines temporary elevation of the number of circulating immune cells with continuous improvement of oxygen transport into tissues. The former is achieved by a peptide mixture isolated from thymus glands in combination with the chemical immunomodulator 2-cyano-ethyl urea; the latter is the outcome of several variants of the O2-multistep therapy discussed here. The efficiency ranges of the different variants are quantified on the basis of findings that allow assessment of the number of tumor cells which can be destroyed by this treatment. This number may be about 100 times the number of malignant cells that must be killed in terms of an effective metastasis prophylaxis (approximately 3 X 10(5)). The estimated efficiency range represents therefore a not yet fully exhausted preventive and possibly even therapeutic potential. To speed the introduction of the procedures described into practice, all clinical oncologists are encouraged to refer their patients to established facilities for O2-multistep immunostimulation after termination of any conventional therapy.
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PMID:Fundamentals of combating cancer metastasis by oxygen multistep immunostimulation processes. 389 51

Beta-2-microglobulin (BMG) is physically linked to the allo-antigenic HLA chain on the cell surface and is accordingly a marker for the HLA antigens. BMG concentrations were measured in serum and cerebrospinal fluid (CSF) samples from 22 patients with choriocarcinoma, 5 with hydatidiform mole and 17 reference subjects in the first trimester of pregnancy. Serum BMG levels were elevated in the patients with choriocarcinoma, particularly when human chorionic gonadotrophin levels were higher than 50 000 U/l (less than 50 000 U/l--1,6 +/- 0,3 mg/l; greater than 50 000 U/l--2,75 +/- 0,72 mg/l; molar pregnancy--1,42 +/- 0,44 mg/l; reference subjects--1,47 +/- 0,15 mg/l) (mean +/- 1 SD). BMG levels in the serum and CSF were not increased when metastases were present in the cranium. None of the patients had evidence of abnormal renal function as determined by serum urea, electrolyte and creatinine levels and the creatinine clearance rate. These results suggest that BMG and HLA antigens are expressed on the trophoblastic cells in choriocarcinoma, or alternatively that the maternal immunocytes produce increased quantities of BMG.
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PMID:Beta-2-microglobulin in trophoblastic disease. 619 98

A consecutive series of 10 patients with hepatic metastases from colo-rectal carcinoma have been treated with oral urea. This substance has been reported to produce regression of hepatic secondaries from a variety of primary sources including colon. Although well tolerated, and leading to subjective improvement in some patients, no objective benefit has been confirmed from the treatment in this study.
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PMID:Oral urea in the treatment of colo-rectal liver metastases. 650 16

Several properties of 10 cell lines derived from the polyoma-induced PW20 Wistar-Furth rat renal sarcoma have been examined, including the ability of the tumor cells to metastasize spontaneously from subcutaneous sites in syngeneic hosts, the platelet-aggregating activity of material extracted by urea from the surface of cultured cells, the sialic acid content of the platelet-aggregating material, and the degree of sialylation of cell surface glycoconjugates in cultured cells. A correlation has been observed among all of these parameters. The results suggest a possible link between the degree of cell surface sialylation of tumor cells, their ability to aggregate platelets, and their ability to metastasize.
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PMID:Correlation between spontaneous metastatic potential, platelet-aggregating activity of cell surface extracts, and cell surface sialylation in 10 metastatic-variant derivatives of a rat renal sarcoma cell line. 693 86

Thirty cases of lip cancer in 28 patients, 23 of which were extensive or very extensive, were treated with local urea injections in combination with curettage. Out of the 30 cases there were 26 squamous cell carcinomas, three basal cell carcinomas extending to the mucosa from the skin of the lips, and one adenocarcinoma of the mucosa of the interior surface of the upper lip. This treatment was effective in all our patients. Recurrences appeared in four patients. These were easily treated in three out of the four patients who returned for treatment, by the same method. In three cases metastases appeared in the lymphnodes of the neck, which were surgically treated.
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PMID:The effects of urea treatment in combination with curettage in extensive lip cancers. 707 90

After discussing the relationships between efficacy of body-own defense, arterial pO2 level and manifestations of both primary tumors and metastases, correlations between immune state and oxygen transport into the entire body are described on the basis of experimental findings. As a conclusion drawn from these results, the precise treatment schedule of a tumor and metastases multistep prophylaxis utilizing immune stimulation by means of derivatives of cyano-ethyl urea and fortification of oxygen transport into tissues is given.
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PMID:[Oxygen multistep therapy and cancer. New perspectives in cancer immunology (author's transl)]. 727 32

The metastatic capacity of rat mammary tumors induced with N-nitrosomethyl urea was tested in BUF/N inbred female rats by successive transplantation. After the first and second passage, tumor cells appeared diffusely distributed throughout the bone marrow and spleen, confirming results reported by others; no other metastases were observed. After six successive transplantations, large, well-defined tumor nodules were observed in the liver, spleen, lung, and the peritoneal surface of the intestines in 40% of the injected animals. The morphology of the primary and metastatic tumors was compared by light microscopy. The tumors appeared to be adenocarcinomas with differing degrees of differentiation. No morphological differences could be observed between the primary and the metastatic tumors.
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PMID:Pathology of metastasizing tumors in nitrosomethyl urea-induced rat mammary carcinoma. 728 15

As a part of the National Cancer Institute's effort to screen environmental and occupational chemicals for chronic toxicity and carcinogenicity, the amides acetamide, hexanamide, adipamide, urea, and p-tolylurea were fed to male and female C57B1/6 mice and Fischer 344 rats from 12 months. Rats received the following concentrations of compounds in their diets: acetamide, 2.36%; hexanamide, 1.5%; adipamide, 2.4% and 5.8%; urea, 0.45%, 0.9%, and 4.5%; and p-tolylurea, 0.2%. Mice received acetamide, 1.18% and 2.36%; hexanamide, 1.0% and 1.5%; adipamide, 1.6% and 2.4%; urea, 0.45%, 0.9%, and 4.5%; and p-tolylurea, 0.2%. In acetamide treated rats, there was a compound-related occurrence of neoplastic nodules (1/47 male, 3/48 female) and hepatocellular carcinomas (41/47 male, 33/48 female). The incidence, speed of onset and frequency of metastases, were greater in males than in females. In male mice treated with acetamide (low dose, 7/50; high dose, 7/46); hexanamide (low dose, 6/35; high dose, 6/39); and p-tolylurea (10/43), there was a compound-related increase in hematopoietic tumors, namely malignant lymphomas. Therefore, under the conditions of these studies, acetamide was an hepatocarcinogen in rats. In male mice, acetamide, hexanamide, and p-tolylurea caused malignant lymphomas. Urea and adipamide were considered to be non-carcinogenic.
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PMID:Carcinogenesis bioassay of acetamide, hexanamide, adipamide, urea and P-tolylurea in mice and rats. 744 Oct 78


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