UMLS:C0025202 - FACTA Search

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Query: UMLS:C0025202 (melanoma)
69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Following therapeutic administration, cyclophosphamide and Adriamycin are biotransformed to reactive metabolites, some of which are responsible for undesirable systemic toxicities of these chemicals, whereas others are responsible for their chemotherapeutic effectiveness. Microsomal mixed function oxidases activate cyclophosphamide to produce phosphoramide mustard and acrolein, while cytochrome reductase and xanthine oxidase are capable of transforming Adriamycin and forming free radicals. These reactive metabolites produce unwanted toxic side effects; however, their action may be partially ameliorated by the concomitant administration of thiols. In this study we evaluated the therapeutic activity of combinations of mesna (2-mercaptoethanesulfonate) with cyclophosphamide or Adriamycin in mice with a variety of transplantable tumors (L1210 and P-388 leukemia, Lewis lung and colon 26 carcinoma, B16 melanoma, and M5076 sarcoma). In all cases the administration of mesna prior to cyclophosphamide or Adriamycin treatment did not reduce the antitumor effectiveness of these agents and in some instances (C57BL/6 mice with B16 melanoma or M5076 sarcoma) small improvements were observed. Therefore, the addition of thiols, to reduce effectively the buildup of toxic metabolites of cyclophosphamide or Adriamycin may result in the improved therapeutic effectiveness for these agents in the treatment of cancer.
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PMID:Combinations of mesna with cyclophosphamide or adriamycin in the treatment of mice with tumors. 310 25

The purpose of these studies was to determine the effect of Adriamycin (ADR) on the ability of liposome-encapsulated immunomodulators to activate human blood monocytes to the tumoricidal state. We undertook these experiments because we envisioned using encapsulated activators in addition to chemotherapy to destroy pulmonary micrometastases in patients with osteosarcoma (OS). Prior to the initiation of such therapy, it was important to determine whether chemotherapy interferes with monocyte function. First, human peripheral blood monocytes were isolated from normal donors and preincubated with ADR (0.5-500 ng/ml) for 1 h and then washed prior to the addition of free or liposome-encapsulated activators. After 18-24 h incubation, the activating agents were washed off and [125I]IdUrd-labeled A375 melanoma cells were added. Lysis of radiolabeled tumor cells was quantified 72 h later. Monocytes were also incubated with ADR for 24 h in the presence of free or liposome-encapsulated activators and their cytotoxicity quantified. ADR had no effect on the ability of either free or liposome-encapsulated agents to activate monocyte tumoricidal function. We also studied the in vivo effect of ADR therapy on monocyte function in nine patients with OS. At the time of diagnosis and 1 month after ADR therapy (75 mg/m2) patient monocytes could be activated to the tumoricidal state by liposome-encapsulated agents at levels equal to or greater than pretherapy levels. Monocytes isolated from four patients with OS 1 day after ADR therapy and then activated by liposome-encapsulated agents also demonstrated tumoricidal activity. These studies indicated that the monocytes isolated from osteosarcoma patients treated with ADR can be activated in vitro to kill tumor cells and that additional therapy with liposome-encapsulated immunomodulators may be combined with ADR in the treatment of metastatic pulmonary OS.
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PMID:In vitro and in vivo effect of adriamycin therapy on monocyte activation by liposome-encapsulated immunomodulators. 326 32

Doxorubicin (DXR) conjugated to a monoclonal antibody (MAb), 9.2.27, which recognizes a human melanoma-associated proteoglycan, effectively suppresses the growth of human melanoma xenografts and prolongs the life span of tumor-bearing athymic nude (nu/nu) mice. We have investigated further the mechanism(s) of this in vivo antitumor activity. Our results indicate that following iv injection, the DXR-MAb 9.2.27 conjugate is cleared from the circulation with typical biphasic kinetics, similar to the clearance process of the unconjugated MAb 9.2.27. In contrast, less than 10% of injected dose per milliliter of blood is found in the circulation at any given time after ip injection. Toxicity studies further indicate that DXR-MAb 9.2.27 conjugate is less toxic in vivo than the freely administered DXR, which is known to cause considerable cardiotoxic effects. Direct autoradiography demonstrates that the DXR-MAb 9.2.27 conjugate binds specifically to the tissue sections derived from a human melanoma xenograft of a nude mouse. A critical evaluation is given of the relevance of these findings and their impact on the design of future strategies for the immunochemotherapy of malignant melanoma.
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PMID:Pharmacokinetics and mechanism of action of a doxorubicin-monoclonal antibody 9.2.27 conjugate directed to a human melanoma proteoglycan. 326 3

1-beta-D-Arabinofuranosylcytosine (ara-C) was tested at a concentration of 10 micrograms/ml in the human tumor colony-forming assay against 55 human tumors of various histological types. Using the criterion for sensitivity of at least 70% inhibition of colony formation, 12 tumors (22%) were sensitive to ara-C. ara-C was most active against lung tumors (3 of 8 tumors were sensitive), and melanomas (6 of 8 sensitive). However, ara-C was not active against breast cancer (0 of 7) or colon cancer (0 of 3), and only 1 of 13 ovarian cancers was sensitive to ara-C. The activity of ara-C against melanoma and other solid tumors was confirmed using a thymidine incorporation assay. The time (t) and concentration (C) dependency of the cytotoxicity of ara-C and other chemotherapeutic agents was determined. Most agents such as Adriamycin, cis-diamminedichloroplatinum(II) (cis-platinum), and bleomycin were found to follow the C x t rule. That is, as the drug concentration was doubled, an equivalent amount of cell kill was achieved in half the time. However, the activity of ara-C was more concentration dependent than time dependent. ara-C was more effective when cells were exposed to high concentrations for short time periods. Synergy of activity between ara-C and cis-platinum was demonstrated in the breast 231 and melanoma M19 cell lines. No synergy of interaction between these two drugs was observed in the colon HT29 and lung P3 cell lines. When fresh biopsy specimens were tested with the combination, there was evidence of a synergistic interaction in 9 of 36 (25%). Maximum cytotoxicity was obtained when cells were exposed to ara-C 2 h before the addition of cis-platinum. The addition of cis-platinum before ara-C decreased the synergism.
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PMID:In vitro pharmacodynamics of 1-beta-D-arabinofuranosylcytosine: synergy of antitumor activity with cis-diamminedichloroplatinum(II). 333 86

The effect of the combined administration of verapamil (i.p. twice daily) and doxorubicin (i.v. once weekly) was tested in mice bearing the following: (a) a tumor with induced resistance to doxorubicin (B16VDXR melanoma line); (b) a tumor inherently resistant (MXT mammary carcinoma); and (c) four solid tumors sensitive to doxorubicin (B16 melanoma, B16V melanoma line, M5076 reticulum cell sarcoma, and Lewis lung carcinoma). Verapamil, given according to this treatment schedule, reached peak plasma concentrations of 3 microM. Such treatment did not enhance doxorubicin activity on either inherently or induced resistant tumors, whereas it significantly enhanced doxorubicin growth inhibition in all the sensitive tumors except the Lewis lung carcinoma. Doxorubicin pharmacokinetics after administration of the drug alone and in combination with verapamil was analyzed after the first and repeated treatments in animals bearing B16 melanoma or its resistant subline B16VDXR. The resistance of the B16VDXR line was associated with the ability of the tumor to retain less doxorubicin (AUC = 83 micrograms h/g) than the sensitive tumor B16 (AUC = 204 micrograms h/g) in spite of similar initial levels. The potentiating effect of doxorubicin activity by verapamil in B16 melanoma was not associated with increased doxorubicin levels or retention in the tumor, nor were differences in doxorubicin levels or retention found in the B16VDXR line. The combined treatment did not modify doxorubicin pharmacokinetics in plasma, heart, or spleen. These studies suggest that verapamil in vivo is ineffective in potentiating doxorubicin activity in tumors against which doxorubicin is inactive, that sensitive tumors are heterogeneous in their sensitivity to modulation by verapamil, and that this effect is not associated with modification of doxorubicin pharmacokinetics.
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PMID:Effect of verapamil on doxorubicin activity and pharmacokinetics in mice bearing resistant and sensitive solid tumors. 337 Jul 42

Doxorubicin (DXR) was covalently conjugated to a monoclonal antibody (mAb), 9.2.27 (IgG2a), which recognizes a chondroitin sulfate proteoglycan expressed preferentially on the surface of human melanoma cells. Immunoconjugates with a molar ratio of DXR to mAb ranging from 2:1 to 10:1 were obtained by coupling the drug via an acid-sensitive linker, cis-aconitic anhydride. The immunoreactivity of mAb 9.2.27 was well retained after conjugation. DXR-mAb 9.2.27 conjugates were found to be 2 orders of magnitude more potent in killing tumor cells in vitro (IC50 = 0.1 microM) than free drug targeted to drug receptor(s). Most significantly, DXR-mAb 9.2.27 immunoconjugates specifically suppressed the growth of established tumors in vivo and prolonged the life-span of tumor-bearing nude mice. This suppression of melanoma growth achieved by the immunoconjugate was both tumor and antibody specific. A biodistribution study indicated that DXR-mAb 9.2.27 conjugates delivered at least 4 times more DXR (3.7% total injected dose per g of tumor) as compared to free DXR alone (0.8% total injected dose per g of tumor) in tumor-bearing nude mice 48 hr postinjection. The tumor-suppressive effects of DXR-mAb 9.2.27 conjugates are even more remarkable since free DXR did not suppress tumor growth in vivo and also because this drug per se is known to be quite ineffective for the treatment of human melanoma.
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PMID:Doxorubicin conjugated with a monoclonal antibody directed to a human melanoma-associated proteoglycan suppresses the growth of established tumor xenografts in nude mice. 342 87

Human melanoma cells resistant to killing by monoclonal antibody R24 plus human complement became susceptible after treatment with doxorubicin (adriamycin). Treatment with doxorubicin prevented the rapid degradation of surface-bound complement component C3b that has been identified as a protective mechanism of complement-resistant melanoma cells. Doxorubicin caused the increased complement susceptibility as free drug and after immobilization onto glass beads to prevent cellular uptake. Immobilized doxorubicin was more effective than free drug, causing enhanced complement susceptibility at concentrations where the free drug was no longer active. In contrast to free doxorubicin, which exhibited a direct cytotoxic effect leading to cell death within 4 days, immobilized doxorubicin did not affect cell viability. These findings suggest that combination therapy of the complement-activating monoclonal antibody R24 with the complement-enhancing drug doxorubicin may be a promising approach for the treatment of melanoma.
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PMID:Immobilized doxorubicin increases the complement susceptibility of human melanoma cells by protecting complement component C3b against inactivation. 346 79

The limitations of the agar suspension culture method for primary culturing of human tumor cells prompted development of a monolayer system optimized for cell adhesion and growth. This method grew 83% of fresh human tumor cell biopsy specimens, cultured and not contaminated, from a heterogeneous group of 396 tumors including lung cancer (93 of 114, 82%); melanoma (54 of 72, 75%); sarcoma (46 of 59, 78%); breast cancer (35 of 39, 90%); ovarian cancer (16 of 21, 76%); and a miscellaneous group consisting of gastrointestinal, genitourinary, mesothelioma, and unknown primaries (78 of 91, 86%). Cell growth was characterized morphologically with Papanicolaoustained coverslip cultures and cytogenetically with Giemsastained metaphase spreads. Morphological features such as nuclear pleomorphism, chromatin condensation, basophilic cytoplasm, and melanin pigmentation were routinely seen. Aneuploid metaphases were seen in 90% of evaluable cultures, with 15 of 28 showing 70% or more aneuploid metaphases. Colony-forming efficiency ranged between 0.01 and 1% of viable tumor cells, with a median efficiency of 0.2%. This culture system uses a low inoculum of 25,000 viable cells per well which permitted chemosensitivity testing of nine drugs at four doses in duplicate from 2.2 X 10(6) viable tumor cells and radiation sensitivity testing at five doses in quadruplicate from 0.6 X 10(6) cells. Cultures were analyzed for survival by computerized image analysis of crystal violet-stained cells. Drug sensitivity studies showed variability in sensitivity and in survival curve shape with exponential cell killing for cisplatin, Adriamycin, and etoposide, and shouldered survival curves for 5-fluorouracil frequently seen. Radiation sensitivity studies also showed variability in both sensitivity and survival curve shape. Many cultures showed exponential cell killing, although others had shouldered survival curves. This method for growing cells from primary human biopsy specimens is more efficient than the agar culture method, enables easier and better biological analysis of the actual cells grown, and permits improved characterization of drug and radiation survival curves.
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PMID:Drug and radiation sensitivity measurements of successful primary monolayer culturing of human tumor cells using cell-adhesive matrix and supplemented medium. 348 78

An experimental model of meningeal carcinomatosis has been produced by subarachnoid inoculation of B16 melanoma cells into C57BL mice. Injection of 10(3) viable cells was sufficient to cause 100% tumor incidence and death within a median survival time of 17 days. The tumor infiltrated diffusely the meninges of the brain and spinal cord and filled the ventricular system. Electron microscopic study of the leptomeningeal tumor revealed newly formed microvessels with fenestrated endothelium. The integrity of the blood-brain barrier was studied by the extravasation of the Evans blue and the Horseradish peroxidase tracers. Barrier disruption became evident from the seventh day on, using Evans blue. Electron microscopy study showed peroxidase activity in the luminal and abluminal sides of the meningeal microvessels, and within the tight junctions. Similar findings were noted in cortical capillaries adjacent to the meningeal tumor. Brain concentrations of Adriamycin (ADR) following administration of an intravenous dose of either 10 mg/kg or 50 mg/kg were measured on days 0 to 14 after tumor inoculation. A significant increase in mean +/- SEM content of whole brain ADR was observed only with the 50 mg/kg dose in days 7 to 14 (0.69 +/- 0.02 micrograms/g wet tissue weight) as compared to tumor-free controls (0.43 +/- 0.01, p less than 0.05). Our study suggests that barrier alteration in meningeal carcinomatosis allows extravasation of tracer solutes. Still, in order to achieve a significant increase in a water soluble drug penetration through the disrupted barrier, a high-dose drug regimen is required.
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PMID:Alteration of blood-brain-CSF barrier in experimental meningeal carcinomatosis. A morphologic and adriamycin-penetration study. 355 64

A B16 mouse melanoma cell line resistant to doxorubicin was obtained by continuous in vitro exposure to the drug. The ID50 for this line was 200 times higher than that for the parental cell line. The resistant cell line had some biological characteristics similar to those of the sensitive parental cell line, like saturation density and protein content. Differences were found in doubling time which was longer, cloning efficiency which was lower and DNA content which was higher in the resistant as compared to the parental line. Intracellular distribution of doxorubicin was also different having a nuclear-cytoplasmic ratio higher in sensitive than in resistant cells. Melanin content was an unstable feature in the sensitive cell line, whereas melanin was always present in resistant cells. Resistance to doxorubicin was maintained during 50 in vitro passages in the absence of the drug. Cross-resistance was found with vincristine and other anthracyclines, like daunorubicin and 4'-epi-doxorubicin but not with cis-platinum, and a new doxorubicin derivative, 4'-deoxy-4'-iodio-doxorubicin. The B16 line showed a lower resistance index to 4'-deoxy-doxorubicin and 4-demethoxy-daunorubicin (30 and 3 respectively), as compared to doxorubicin. Doxorubicin-resistance was partially circumvented by pretreatment of resistant cells with verapamil, a calcium chelating agent, and by trifluoperazine, a calmodulin-antagonist.
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PMID:Characterization of a doxorubicin-resistant murine melanoma line: studies on cross-resistance and its circumvention. 373 Feb 55

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