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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The size of the lung cancer problem and the dismal results of conventional therapy justify close attention to the possibilities of immunotherapy. Lung cancer patients, like other tumor patients, are often relatively immunosuppressed although an immune response directed against autochthonous tumor cells can usually be demonstrated. All conventional forms of therapy, surgery, chemotherapy, and particularly radiation therapy, are further immunosuppressive, which, there is reason to believe, jeopardizes a successful outcome. Immunotherapy seeks to counteract this either by nonspecfic immunoenhancement or by enhancing reactivity to tumor specific antigens. The results of immunotherapy trials in lung cancer patients suggest that survival can be prolonged and survivorship increased by immunotherapy, although the benefit is inconclusuve at present. Optimal conditions for immunotherapy, as presently understood, are outlined. Practical questions about the optimal use of current immunotherapy regimens need to be answered, but a more aggressive approach to lung cancer therapy when combined with immunotherapy seems justified. Im pariicular, the criteria for operability will need to be redefined, particularly as regards oat cell cancer and large tumors which cannot be completely resected but in which "debulking" may contribute to the success of subsequent radiation and immunotherapy. Possible future immunotherapy regimens applicable to lung cancer are proposed, with the reservation that their success is likely to be directly related to their practicability.
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PMID:Lung cancer: An immunologic viewpoint and the prospects for immunotherapy. 125 3

Pyran copolymer (NSC 46015) was found to potentiate strongly the immune response of C57BL/6J X DBA/2 F1 mice to 10(4) live L1210 tumor cells following suboptimal vaccination with 10(7) radiation-inactivated L1210 cells. Optimal immunity to challenge was produced by concomitant i.p administration of pyran and L1210 vaccine, and activity was dependent upon both pyran and vaccine dosages. In addition, this immunopotentiation seemed to be related to the intrinsic viscosity of different pyran preparations tested, although all the pyran compounds had significant activity. Furthermore, the increased immunity of subsequent live tumor challenge appeared to be specific for the vaccinating cell type.
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PMID:Specific potentiation of L1210 vaccine by pyran copolymer. 126 55

A bioassay is described for the quantitation of tumor cells in blood specimens in a syngeneic mouse tumor system (Sarcoma 1 in A/J mice). The procedure involved i.m. injection of blood containing tumor cells into each thigh of normal recipient mice and, 14 days later, examination of the sites of injection for evidence of tumor growth. For each specimen, a tumor index was calculated based on the number of tumor takes and the size of the tumors. The number of tumor cells was determined by comparison with tumor indices from standard specimens with known number of tumor cells. Optimal conditions for this assay were investigated. We have used this bioassay to quantitate tumor cells in the venous blood of tumor-bearing animals under various treatments and manipulations. At the same time, the incidence of regional node metastasis was obtained by direct histological examination. Surgical removal of a well-established primary tumor enhanced the dissemination of the tumor, as evidenced by an increased incidence in regional node metastasis and an increase in the number of tumor cells reaching the venous circulation. Similar results were obtained when the tumor-bearing feet were ligated to produce ischemia of the primary tumor. Repeated physical trauma to the primary tumor resulted in increased dissemination of tumor cells into the venous circulation, but it did not increase the incidence of regional node metastasis. Immunosuppression of the tumor-bearing animals increased the dissemination of tumor cells, whereas immunostimulation decreased the dissemination.
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PMID:Bioassay for quantitating circulating tumor cells in a syngeneic mouse tumor system. 126 58

The relatively small concentrations required for in vivo bioactivity of diterpene ester skin irritants and promoters (approximately 10 nmol per animal; approximately 10 nM in cell cultures) has discouraged studies of EPR spectra of bioactive, TPA-analogous, spin-labeled phorbol-12,13-diesters [(n,m)PA] bound to their membrane receptors, protein kinases C (PKC). To meet the requirements of present EPR spectrometers, particulate fraction from mouse brain containing at least 25 x 10(-12) mol of receptors/mg protein (PKC species) were employed together with certain (n,m)PA selected to give an optimal ratio of specific to non-specific binding. For selection and optimization of experimental conditions, a theoretical model was developed that considers all characteristic parameters of the system. By fitting the model calculations to the experimental data of competitive agonist displacement from the particulate fraction of tritium-labeled TPA, the dissociation constants Kd for four selected (n,m)PA used as antagonists were determined. Optimal experimental conditions are met by (5,6)PA and by (5,8)PA, in that for both compounds the relative amount of displaced (n,m)PA is in accordance with the predictions derived from the model. Moreover, the model turned out also to be reliable for samples containing either small or large amounts of membranes. To obtain an EPR spectrum of an agonist bound to brain particulate fraction, the (5,6)PA was used. It shows a broad EPR spectrum typical for an immobilized molecule. The spectrum changes if an excess of TPA is added to the system; the slight differences in shape are due to displacement of (5,6)PA from specific receptor sites by non-labeled TPA and show up as a decreased central peak amplitude. This is the first time that the agonist/receptor interaction of a diterpene ester type irritant and tumor promoter has been demonstrated by direct spectroscopic measurement.
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PMID:Spin-labeled phorbol esters and their interactions with cellular membranes--V. Electron paramagnetic resonance of spin-labeled phorbol-12,13-diesters bound to their receptors in mouse brain particulate fraction. 131 Sep 6

Systemically administered tumour necrosis factor (TNF) has anti-tumour effects in animal tumour models but its clinical application is limited by severe toxicity. Interferon-gamma(IFN-gamma) has been shown to augment the anti-tumour effect of TNF. We evaluated the effect of paralesional (p.I.) injections of TNF plus IFN-gamma in a murine tumour model and compared the toxicity and anti-tumour effect with that seen with systemic administration. C57BL6 mice with 10-day subcutaneous MCA sarcomas were treated with daily p.I. injections of recombinant huTNF +/- IFN-gamma for 5 days. Optimal mean survival and 30-day cure rate was seen with doses of 5 micrograms TNF-alpha + 5000 U IFN-gamma (P < 0.05 vs. control or IFN-gamma alone). Tumour response after a single i.v. injection of 0-15 micrograms TNF + 5000 U IFN-gamma was then compared with five daily p.I. injections of the same dose of TNF-alpha and IFN-gamma. All animals with p.I. injections of > 5 micrograms TNF had initial complete necrosis of tumour with a variable degree of surrounding tissue necrosis, with rapid regrowth of tumour seen in some animals. Although treatment-related mortality was similar between i.v. and p.I. therapy, there was a higher percentage of animals cured with p.I. injections with overall cure rates in treated animals at 30 days of 17% vs. 72% (i.v. vs. p.I., P < 0.01) and 13% vs. 67% (P < 0.04) in a repeat study. 2+ clinical applications.
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PMID:Effective regional therapy of experimental cancer with paralesional administration of tumour necrosis factor-alpha + interferon-gamma. 134 Dec 63

Scintigraphy with 123I-Tyr-3-octreotide has several major drawbacks as regards its metabolic behavior, its cumbersome preparation and the short physical half-life of the radionuclide. The use of another radiolabeled analog of somatostatin, 111In-DTPA-D-Phe-1-octreotide, has consequently been proposed. DTPA-D-Phe-1-octreotide can be radiolabeled with 111In in an easy single-step procedure. DTPA-D-Phe-1-octreotide is cleared predominantly via the kidneys. Fecal excretion of radioactivity amounts to only a few percent of the administered radioactivity. For the radiation dose to normal tissues, the most important organs are the kidneys, the spleen, the urinary bladder, the liver and the remainder of the body. The calculated effective dose equivalent is 0.08 mSv/MBq. Optimal 111In-DTPA-D-Phe-1-octreotide scintigraphic imaging of various somatostatin receptor-positive tumors was obtained 24 hr after injection. In the six patients studied, tumor localization with 123I-Tyr-3-octreotide and with 111In-DTPA-D-Phe-1-octreotide were found to be similar. However, the normal pituitary is more frequently visualized with the latter radiopharmaceutical. In conclusion, 111In-DTPA-D-Phe-1-octreotide appears to be a sensitive somatostatin receptor-positive tissue-seeking radiopharmaceutical with some remarkable advantages: easy preparation, general availability, appropriate half-life and absence of major interference in the upper abdominal region, because of its renal clearance. Therefore, 111In-DTPA-D-Phe-1-octreotide may be suitable for use in SPECT of the abdomen, which is important in the localization of small endocrine gastroenteropancreatic tumors.
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PMID:Somatostatin receptor scintigraphy with indium-111-DTPA-D-Phe-1-octreotide in man: metabolism, dosimetry and comparison with iodine-123-Tyr-3-octreotide. 134 39

Optimal synchronization of breast cancer cell proliferation by hormonal means may be limited by cellular heterogeneity in sensitivity to the multistep activation of growth following initial hormone binding to the receptor. We hypothesized that induced synchronous growth may be improved by combined manipulation of the polyamine (PA) pathway since we have previously shown that PAs are distal effectors of hormonal action on proliferation in breast cancer. To test our hypothesis, we induced an initial phase of hormone and PA depletion (castration plus administration of the PA synthesis inhibitor alpha-difluoromethylornithine) in rats bearing N-nitrosomethylurea induced mammary tumors. This was followed by transition phase of hormone repletion in the presence of alpha-difluoromethylornithine (to push the cells into the proliferative cascade up to the distal step controlled by PA) and finally a phase of hormone and PA repletion. Simultaneously, groups of rats were subjected to hormone/PA depletion/repletion individually. The effects of these manipulations on the labeling indices (LIs) of glandular, myoepithelial, and nonepithelial cells were estimated by autoradiography. The combined hormone/PA manipulation yielded the highest degree of synchronization with LIs of the glandular and myoepithelial cells being approximately 2-fold over intact control after only 2 or 3 days of combined repletion. In contrast, hormone treatment alone restored the LIs of glandular cells only to control levels and minimally influenced those of myoepithelial cells. PA manipulation alone failed to affect the LIs of any cell type. Although the rate of tumor regrowth was highest with the combination treatment, the absolute tumor volumes did not differ significantly at the end of the repletion phase between the three regimens. These results indicate that combined hormone/PA manipulation provides the best "therapeutic window" (LI/tumor volume) for implementation of kinetically based cytotoxic chemotherapy.
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PMID:Synchronization of breast cancer cell proliferation in vivo by combined hormonal and polyamine manipulation. 139 95

The constitutive expression by eight human bladder cancer cell lines of the cell adhesion molecules intercellular adhesion molecule-1 and intercellular adhesion molecule-2 was studied using monoclonal antibody probes in conjunction with flow-cytometry. Tumour lines of low grade (G1) did not constitutively express intercellular adhesion molecule-1, rather they were found to express intercellular adhesion molecule-2. The G2 cells expressed no intercellular adhesion molecule-2, however, a low percentage did express intercellular adhesion molecule-1. High grade cells (G3) only expressed intercellular adhesion molecule-1 on their cell surface but at higher levels than the G2 cell line. Exposure of the bladder cancer cell lines to interferon-gamma induced and augmented the expression of intercellular adhesion molecule-1 by all except one of the cell lines (UMUC3). Intercellular adhesion molecule-2 expression remained unaltered. The modulation of intercellular adhesion molecule-1 expression was dependent on the concentration of interferon-gamma and the duration of stimulus. De novo intercellular adhesion molecule-1 expression, induced by interferon-gamma, was rapid (< 4 hours) with only a short period of stimulation being required (< 10 seconds). The rapid increase in expression of intercellular adhesion molecule-1 required de novo protein synthesis and was not the result of release of intercellular adhesion molecule-1 from an intracellular pool. Interferon-gamma and tumour necrosis factor-alpha were found to act synergistically in the induction and augmentation of intercellular adhesion molecule-1 expression. Optimal induction occurred with 10 Uml-1 of both molecules. These results suggest a correlation between constitutive adhesion molecule expression and the histopathological grade of the tumour. The implications of these findings for Bacillus Calmette Guerin and interferon-gamma immunotherapy of bladder cancer is discussed.
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PMID:Expression of adhesion molecules by bladder cancer cells: modulation by interferon-gamma and tumour necrosis factor-alpha. 143 72

Cytogenetic alterations that characterize different histologic subtypes of soft tissue sarcomas have been identified. In a few situations, more precise chromosomal mapping has allowed identification of certain genes that may be involved in the development or tumor progression of sarcomas. Careful family histories must be elicited in sarcoma patients. While "cancer families" are rarely identified when screening close relatives of sarcoma patients, the discovery of the currently known tumor suppressor gene syndromes associated with germ line retinoblastoma gene and p53 gene defects were made possible by their association with sarcomas. Optimal management of primary sarcomas includes function-sparing complete resection and radiotherapy. Innovative radiotherapy, utilizing radiation sensitizers or brachytherapy, may increase local control in patients with unresectable tumors. New drugs are needed. Epirubicin and other anthracycline analogues do have significant activity; however, no other novel drugs have documented efficacy. Dose intensity is being explored with sarcoma trials providing the "vehicle" to evaluate new cytokines. Several mechanisms of doxorubicin resistance have been identified in cell lines and fresh tumors, including alterations in glutathione peroxidase activity and MDR-1 gene expression. These observations need to be taken to the clinic.
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PMID:Advances in the diagnosis and management of sarcomas. 151 Oct 24

Cytochrome P-450 species (P-450) comprise a polymorphic multigene family of heme-containing enzymes which are essential to the phase-I metabolism of xenobiotics. Induction of P-450 species by drugs and carcinogens has been extensively studied; endogenous regulation of P-450 also occurs during normal development and disease. The aim of this project was to study the in-vitro induction of P-450 and its modulation by inflammatory mediators in the human lung tumor-derived cell lines NCI H322 and NCI H358. The cell lines expressed detectable levels of 7-ethoxyresorufin O-deethylase which could be induced by benzanthracene. After benzanthracene treatment, a protein tentatively identified as isozyme CYP1A1 was detected by Western-blot analysis and a concommitant increase in CYP1A mRNA expression was observed. Optimal induction was observed at a benzanthracene concentration of 5 micrograms/ml with cells grown in RPMI medium containing 10% fetal calf serum. The effects of endotoxin, dexamethasone and five recombinant DNA-derived cytokines, interleukin-1 beta, tumor necrosis factor, and interferons alpha, beta and gamma, on constitutive and benzanthracene-induced ethoxyresorufin O-deethylase activity were examined in NCI H322 cells. Of all the lymphokines studied, only interferon gamma had any marked effect. Administration of this lymphokine strongly suppressed ethoxyresorufin O-deethylase activity in both control and benzanthracene-treated cells.
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PMID:Cytochrome P-450 induction in human lung tumor-derived cell lines. Characterisation and effects of inflammatory mediators. 152 41


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