Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Melphalan”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

Isolation and characterization of a CHO amino acid transport mutant resistant to melphalan (L-phenylalanine mustard).

A mutant of Chinese hamster ovary cells, CHY-2, was isolated on the basis of its reduced ability to grow on a limiting concentration of leucine and was found to be defective in uptake of leucine via the sodium-independent L system. Consistent with published reports that the L system can mediate melphalan uptake, the D10 of the mutant for melphalan was increased threefold under conditions designed to limit drug uptake to the L system (brief exposure in sodium-free medium). Unlike a previously described melphalan-resistant CHO mutant (CHr), CHY-2 displays no cross-resistance to colchicine or puromycin. It differs from a second melphalan-resistant CHO mutant, melr, in its sensitivity to melphalan in the presence of high Na+, and from a melphalan-resistant mouse leukemic cell in possessing normal levels of intracellular glutathione. Thus, CHY-2 represents a new melphalan-resistant mutant class. The effect of the CHY-2 mutation is pleiotropic, involving significant reductions in amino acid uptake via the L, A and Ly+ (but not ASC) systems. The primary defect is unknown; however, the mutant possesses normal intracellular concentrations of Na+ and K+ and normal membrane fluidity. The growth rate of the mutant in standard medium is greatly reduced (generation time of 60 h vs. 24 h), although it can be improved by the addition of a supplement containing high concentrations of leucine, proline, and peptides.

Amino Acids↗

True versus mild hyperthermia during isolated hepatic perfusion: effects on melphalan pharmacokinetics and liver function.

Hyperthermic antiblastic isolated hepatic perfusion (IHP) with melphalan has been recently proposed as an alternative therapeutic option for patients with unresectable liver tumors. Although melphalan-heat antiblastic synergism is at a maximum at temperatures higher than 41 degrees C, IHP has so far been performed in humans at lower temperatures. In this experimental work, we compared IHP under mild versus true hyperthermic conditions in terms of drug pharmacokinetics and liver function. Ten pigs were submitted to IHP with melphalan 1.5 mg/kg at a mean temperature of 40 degrees C (group A, n = 5) or 42 degrees C (group B, n = 5). After a 60-minute perfusion, a 15-minute washout was performed. Perfusate-to-plasma leakage was monitored using scintigraphy. Throughout perfusion, samples from the systemic blood, perfusate, and liver parenchyma were obtained to measure melphalan concentrations. Liver function was assessed using standard blood tests and the indocyanine green-based test. No deaths related to the IHP procedure were recorded. All animals had transient liver function impairment, with all liver function test results returning to normal within the observation period. At histologic examination, liver damage was similar under both hyperthermic conditions. Melphalan levels in the perfusate were not significantly different in the two study groups (the mean perfusate/plasma area under the curve from 0 to 60 minutes ratios were 463 and 501, respectively). These results correlated well with those obtained using the scintigraphic method. Liver drug concentrations remained unchanged after true hyperthermia IHP. Under true hyperthermic conditions, neither an increase in liver parenchyma toxicity nor changes in melphalan pharmacokinetics were observed. These findings support the use of true hyperthermia in the clinical setting to exploit fully the antitumor synergism between melphalan and heat.

Animals↗

Enhanced melphalan cytotoxicity in human ovarian cancer in vitro and in tumor-bearing nude mice by buthionine sulfoximine depletion of glutathione.

The development of acquired resistance to alkylating agents frequently limits the effectiveness of chemotherapy in the treatment of ovarian cancer. While the resistance to alkylating agents is multifactorial, the association of drug resistance with elevations in glutathione (GSH) is of potential clinical relevance since there exist pharmacologic means to lower intracellular GSH levels. We have used in vitro and in vivo models of human ovarian cancer to demonstrate that selective inhibition of GSH synthesis with L-buthionine-S,R-sulfoximine (L-BSO) leads to a lowering of GSH levels and an increase in cytotoxicity of the alkylating agent melphalan. In the human ovarian cancer cell line NIH:OVCAR-3, derived from a patient clinically refractory to alkylating agents, L-BSO resulted in a 3.6-fold enhancement of melphalan cytotoxicity. This cell line was also adapted for intraperitoneal growth in athymic nude mice. In this in vivo model, in which the mice die of massive ascites and intraabdominal carcinomatosis, L-BSO given orally in drinking water for 5 days decreased GSH levels in the tumor cells by 96% compared to a 79 and 86% reduction in GSH levels in the bone marrow and gastrointestinal mucosa respectively. Lowering of GSH levels with BSO was not accompanied by an increase in lethality for melphalan in non-tumored nude mice. However, in tumor-bearing nude mice, a single melphalan (5 mg/kg) treatment following GSH depletion with L-BSO was markedly superior to treatment with melphalan alone, producing a 72% increase in median survival time. Furthermore, L-BSO treatment of human bone marrow cells prior to melphalan exposure had little effect on melphalan toxicity as assessed in a CFUc-GM assay. These results suggest that treatment with the GSH synthesis inhibitor BSO may preferentially enhance the cytotoxic effects of alkylating agents against human ovarian cancer and overcome acquired resistance.

Animals↗

Combined chemotherapy with ABCM versus melphalan for treatment of myelomatosis. The Medical Research Council Working Party for Leukaemia in Adults.

Both melphalan and cyclophosphamide increase life expectancy in patients with myelomatosis, but few large randomised studies have compared combination chemotherapy regimens with these single agents. In the Vth MRC myelomatosis trial, the survival of 314 patients randomised to receive ABCM (adriamycin, BCNU, cyclophosphamide, and melphalan) as first-line treatment was significantly longer than that of 316 patients given intermittent melphalan (M7) (p = 0.0003). The 75%, median, and 25% survivals were 7, 24, and 42 months, respectively, with M7 and 10, 32, and 56 months, respectively, with ABCM. Stable disease with few symptoms (plateau) was achieved by 61% of patients given ABCM and 49% of those given M7 (p = 0.004). Myelotoxicity was comparable between regimens. Cross-trial analysis suggests that M7 is comparable to melphalan and prednisone or melphalan, prednisone, and vincristine; that the efficacy of ABCM in the Vth trial and VIth MRC trials is comparable; and that ABCM gave better survival than intermittent melphalan regimens in the prognostic groups analysed. The results indicate that ABCM is an acceptable regimen that is more effective than melphalan, with or without prednisone, for first-line treatment of myelomatosis.

Aged↗

The effect of prolonged incubations and heat denaturation on melphalan-induced DNA cross-links as measured by the ethidium bromide fluorescence assay.

Th ethidium bromide fluorescence assay detects DNA interstrand crosslinks following heat denaturation of DNA on the basis of a 20-25 fold enhancement of ethidium bromide fluorescence in the presence of double stranded DNA. This assay has been utilized to detect DNA cross-links produced by melphalan in lymphocytes from chronic lymphocytic leukemia patients. The percentage of DNA cross-links (C) in these cells did not vary linearly with the concentration of melphalan, possibly as a result of DNA fragmentation during a 16 h lysis to degrade RNA. In order to investigate this, DNA was exposed to melphalan and then the Ct was determined immediately after maximal DNA cross-link formation or after a 16 h incubation. The additional incubation period did not alter the linear relationship between Ct and melphalan concentration. Further, the DNA cross-links produced by melphalan does not appear to be heat labile since varying the heat denaturation period from 5 to 15 min had no effect on Ct. These results suggest that this assay can accurately quantitate the percentage of DNA cross-links produced by melphalan and that the curvilinear relationship between Ct and melphalan concentration in malignant human lymphocytes is not due to the ethidium bromide fluorescence assay.

Animals↗

Potentiation of melphalan activity in the KHT sarcoma by the radiosensitizer RSU 1069.

The radiation sensitizer misonidazole (MISO) has been shown to potentiate the cytotoxic action of a variety of anti-cancer agents. Even larger enhancement ratios than those observed with MISO have been found with certain other nitroimidazoles. One agent reported to be particularly effective in combination with the chemotherapeutic agent melphalan is the sensitizer RSU 1069. The present studies therefore were designed to evaluate the effect of combining these two agents in the treatment of intramuscularly growing KHT sarcomas. Tumor response was assessed using an in vivo to in vitro clonogenic cell survival assay. When given at times ranging from 60 min before to 30 min after melphalan exposure, RSU 1069 was found to increase the tumoricidal activity of the chemotherapeutic agent. Complete dose response curves combining RSU 1069 and a range of melphalan doses then were determined. For comparison the effects of combining MISO or benznidazole (BENZO) with melphalan also were evaluated. All sensitizers were administered i.p. either 30 min before (BENZO) or simultaneously with (MISO, RSU 1069) the chemotherapeutic agent. Survival of clonogenic tumor cells assessed 22 to 24 hr after treatment was used to assay tumor response. When combined with melphalan, doses of RSU 1069 (0.38 mmol/kg), BENZO (0.3 mmol/kg) and MISO (5.0 mmol/kg) were found to yield dose modifying factors of 1.6, 1.5, and 1.4, respectively. These results indicate that potentiation of melphalan activity occurs at RSU 1069 doses which are approximately 10-fold lower than those of MISO, making this sensitizer as effective a potentiator of melphalan as so far tested in the KHT sarcoma.

Animals↗

Combination of photodynamic therapy (PDT) and melphalan in experimental tumors.

PURPOSE: To investigate whether application of "early" photodynamic therapy (PDT) using a disulphonated aluminium phthallocyanine photosensitizer can potentiate the action of melphalan in experimental RIF-1 tumors in vivo. METHODS AND MATERIALS: Tumors were irradiated with laser light of wavelength 675 nm 60 min after treatment with the photosensitizer and 15 min after melphalan. Melphalan pharmacokinetics were measured using high performance liquid chromatography with optical detection. RESULTS: Melphalan and PDT when given alone, caused a significant delay in tumor growth. This was increased for the combined treatment. Pharmacokinetic analyses showed that levels of free, unreacted melphalan in freely circulating blood are unaffected by combined treatment. However, significant differences in tumor levels were observed between treatment with melphalan alone or in combination. Whereas in the former, melphalan is still present in tumors after 2 h, it was not detectable even at the earliest time of 15-23 min for the combined treatment. CONCLUSION: The antitumor effects were additive with no evidence of significant potentiation.

Animals↗

Influence of anaesthetics on tumour-cell kill and repopulation in B16 melanoma treated with melphalan.

The influence of anaesthetics on the in vivo response of B16 melanoma to melphalan was studied using an in vitro cell-survival assay. Three anaesthetics were used, Saffan (Althesin) Sagatal (Nembutal) and Hypnorm. When Saffan was administered to tumour-bearing animals before melphalan there was a significant increase in tumour-cell kill. This effect was not observed with Sagatal or Hypnorm. Maximum increase in tumour-cell kill was achieved when Saffan was administered about 1 h before melphalan, and was dependent on Saffan dose. Clonogenic tumour-cell repopulation after melphalan was rapid (TD - 1 day) and the rate was similar from 2 levels of cell kill. When Saffan was combined with melphalan the repopulation rate was the same as with melphalan alone, and the increased cell kill was reflected in increased growth delay. The in vitro response of B16 melanoma cells to melphalan was unaltered by pretreatment with, or simultaneous exposure to Saffan. The results suggest that the mechanism of the enhanced cell kill in vivo is probably due to an indirect systemic effect, rather than a direct effect on the tumour cells.

Alfaxalone Alfadolone Mixture↗

Late immune and haemopoietic functions in plasmacytoma-bearing mice cured by melphalan.

Alkylating agents can cause latent and permanent damage to the bone marrow. We compared the long term effects of melphalan on a number of immune and haemopoietic functions of plasmacytoma bearing BALB/c mice with that of normal mice treated with a similar dose of melphalan. The drug administered orally at a dose of 250 micrograms and 400 micrograms on day 14 and 24 following i.m. inoculation of MOPC-315 plasmacytoma cells resulted in cure of the mice. Their spleen cells showed a permanent impairment of MLR activity, T-cell number and IL-2 production as well as a mild suppression of NK activity for one year after cessation of melphalan therapy. The number of B cells was elevated. In contrast, plasmacytoma-free mice treated with melphalan retained long term normal immune functions, although shortly after melphalan therapy a temporary suppression was noted. On the other hand, melphalan was responsible for bone marrow myeloid stem cell damage since the number of myeloid progenitor cell (CFU-GM) colonies was reduced in both melphalan-treated groups compared to untreated normal controls. Plasmacytoma bearing mice had a shorter survival. These results demonstrate that some late sequelae of alkylating agents are not due to the drug alone; shorter survival and T-cell deficiency are related to the previous presence of the tumour.

Animals↗

Melphalan tissue concentrations in patients treated with regional isolated perfusion for melanoma of the lower limb.

In 14 consecutive patients with recurrent melanoma of the lower limb a total of 35 biopsies were taken at the end of perfusion treatment to assess melphalan tissue concentrations in tumour, skin/subcutis and muscle tissue. In tumour tissue (n = 12) the mean melphalan concentration was 6.8 micrograms g-1, which was significantly higher than that of healthy skin/subcutis (3.2 micrograms g-1; n = 10), but equal to that of muscle tissue (6.5 micrograms g-1; n = 13). The correlation between melphalan concentration in the tissues and the concentration in the perfusate was studied. The latter was assessed in the form of melphalan peak concentration and the area under the curve (AUC0-->60) of the melphalan concentration-time curve. Tumour concentration proved to be correlated linearly with AUC0-->60 (R = 0.6, P = 0.002) and muscle concentration with melphalan peak concentration (R = 0.8, P = 0.04). There was no relation between skin/subcutis concentrations and the perfusate parameters. Further research is warranted to study the relationship between melphalan tissue concentration, tumour response and regional toxicity.

Chemotherapy, Cancer, Regional Perfusion↗

Flunarizine enhancement of melphalan activity against drug-sensitive/resistant rhabdomyosarcoma.

Flunarizine, a diphenylpiperazine calcium channel blocker, is known to increase tumor blood flow. It also interferes with calmodulin function, repair of DNA damage and drug resistance associated with P-glycoprotein. Flunarizine was tested for its ability to modulate either cyclophosphamide- or melphalan-induced growth delay for a drug-resistant rhabdomyosarcoma xenograft (TE-671 MR) and the drug-sensitive parent line (TE-671), in which P-glycoprotein is not involved in the mechanism of drug resistance. Tumour blood flow was increased by 30% after a flunarizine dose of 4 mg kg-1, but no modification in growth delay was induced by melphalan (12 mg kg-1). In contrast, a 60 mg kg-1 dose of flunarizine had no effect on tumour blood flow, but the same dose created significant enhancement in melphalan-induced tumour regrowth delay in both tumour lines. The dose-modifying factor for flunarizine as an adjuvant to melphalan was approximately 2 for both tumour lines. Although blood flow measurements were not performed with the combination of flunarizine and melphalan, the results from flunarizine alone suggested that augmentation of melphalan cytotoxicity is not mediated by changes in blood flow. In contrast, flunarizine did not affect drug sensitivity to cyclophosphamide in groups of animals bearing the drug-sensitive parent tumour line. These results suggest that the mechanism of drug sensitivity modification by flunarizine is not related to modification of tumour blood flow, but may be mediated by modification of transport mechanisms that are differentially responsible for cellular uptake and retention of melphalan as compared with cyclophosphamide.

Animals↗

Effect of melphalan and hyperthermia on p34cdc2 kinase activity in human melanoma cells.

We previously reported that combined treatment with melphalan and mild hyperthermia (1 h at 42 degrees C) caused a synergistic cytotoxic effect in JR8 melanoma cells, paralleled by a stabilisation of a melphalan-induced G2-phase cell block. In this study, we investigated the effect of melphalan and hyperthermia on proteins that regulate G2-M transition. Neither hyperthermia nor melphalan at a concentration of 2.5 micrograms ml-1, which had no antiproliferative effect at 37 degrees C, interfered with cyclin B1 expression or p34cdc2 kinase activity. At a concentration of 8.5 micrograms ml-1, which reduced cell growth by 50% at 37 degrees C, melphalan inhibited p34cdc2 kinase activity as a consequence of an increased tyrosine phosphorylation of the protein. A similar inhibitory effect on p34cdc2 kinase was obtained when the lowest melphalan concentration (2.5 micrograms ml-1) was used under hyperthermic conditions. Our results indicate that thermal enhancement of melphalan cytotoxicity could be mediated at least in part by an inhibition of p34cdc2 kinase activity, which prevents cell progression into mitosis.

Antineoplastic Agents, Alkylating↗

Acute renal insufficiency after high-dose melphalan in patients with primary systemic amyloidosis during stem cell transplantation.

BACKGROUND: Patients with primary systemic amyloidosis (AL) have a poor prognosis. Median survival time from standard treatments is only 17 months. High-dose intravenous melphalan followed by peripheral blood stem cell transplant (PBSCT) appears to be the most promising therapy, but treatment mortality can be high. The authors have noted the development of acute renal insufficiency immediately after melphalan conditioning. This study was undertaken to further examine its risk factors and impact on posttransplant mortality. METHODS: Consecutive AL patients who underwent PBSCT were studied retrospectively. Acute renal insufficiency (ARI) after high-dose melphalan was defined by a minimum increase of 0.5 mg/dL (44 micromol/L) in the serum creatinine level that is greater than 50% of baseline immediately after conditioning. Urine sediment score was the sum of the individual types of sediment identified on urine microscopy. RESULTS: Of the 80 patients studied, ARI developed in 18.8% of the patients after high-dose melphalan. Univariate analysis identified age, hypoalbuminemia, heavy proteinuria, diuretic use, and urine sediment score (>3) as risk factors. Age and urine sediment score remained independently significant risk factors in the multivariate analysis. Patients who had ARI after high-dose melphalan underwent dialysis more often (P = 0.007), and had a worse 1-year survival (P = 0.03). CONCLUSION: The timing of renal injury strongly suggests melphalan as the causative agent. Ongoing tubular injury may be a prerequisite for renal injury by melphalan as evidenced by the active urinary sediment. Development of ARI adversely affected the outcome after PBSCT. Effective preventive measures may help decrease the treatment mortality of PBSCT in AL patients.

Acute Kidney Injury↗

Study of lymphotropic targeting and macrofilaricidal activity of a melphalan prodrug on the Molinema dessetae model.

This study deals with the design of a new macrofilaricidal drug derived from melphalan and having a lymphotropism to avoid the hepatic first pass effect and enhance bioavailability after oral administration. Melphalan was linked to a ligand leading to a prodrug called 1,3-dp-melphalan which has structural analogy to triglycerides. The Molinema dessetae/Proechimys oris model was used for antiparasitic evaluation. Melphalan was macrofilaricidal in vitro against Molinema dessetae at 1mM, inactive in vivo after an oral single dose at 164 mumol/kg while the prodrug 1,3-dp-melphalan was active against adult worms after a single dose at 82 mumol/kg. After an oral administration of the prodrug to rats, the maximum concentration and the cumulated quantities of melphalan in lymph were about 45-fold higher than those observed with the free drug under the same conditions. Moreover, the plasma concentration of melphalan was 2-fold higher than those observed after the administration of the free drug. These results are in favor of lymphotropic targeting as a novel approach to develop new orally active macrofilaricides.

Animals↗

A monoclonal antibody that recognizes alkali-stabilized melphalan-DNA adducts and its application in immunofluorescence microscopy.

Monoclonal antibodies were produced that recognized alkali-stabilized modifications of DNA formed by the anticancer drug melphalan in order to permit measurement of melphalan-DNA adducts in individual cells by immunofluorescent staining. Antibody Amp4/42 did not bind to alkali-treated control DNA or to DNA that had been alkylated with melphalan but not exposed to alkali. In a competitive enzyme-linked immunoadsorbent assay using DNA that had been reacted with radioactive melphalan in simple solution a 50% reduction in assay signal was caused by approximately 100 fmol total melphalan-DNA adducts/assay well. This sensitivity was only slightly influenced by heat denaturation of the DNA before alkylation or by the frequency of alkylated sites on DNA. The heat stability of the adducts recognized by Amp4/42 was greatly increased by the alkali-induced change which, in 0.1 M NaOH at 37 degrees C, was complete by 30 min. Amp4/42 appears to recognize a ring-opened structure resulting from alkaline hydrolysis of 7-alkyldeoxyguanosine. Melphalan-DNA adducts formed in mammalian cells showed an alkali-induced increase in immunoreactivity which occurred at a similar rate to that seen in DNA that had been alkylated in simple solution, but their maximum overall immunoreactivity was approximately 10-fold lower. This indicated that in cells the adducts recognized by Amp4/42 were formed or persisted as a smaller proportion of total adducts compared with alkylation of pre-purified DNA in simple solution. This antibody permitted immunofluorescent detection of melphalan-DNA adducts in single cells.

Animals↗

Radiopharmaceutical therapy of 5T33 murine myeloma by sequential treatment with samarium-153 ethylenediaminetetramethylene phosphonate, melphalan, and bone marrow transplantation.

BACKGROUND: Total-body irradiation, followed by hematopoietic system rescue by bone marrow transplantation (BMT), has been found to improve the response of patients with multiple myeloma to treatment with melphalan. The problems of nonhematopoietic toxicity from whole-body irradiation might be circumvented by using a bone-seeking radiopharmaceutical, such as samarium-153 ethylenediaminetetramethylene phosphonate (153Sm-EDTMP), to ablate the bone marrow. PURPOSE: A mouse model system for multiple myeloma was used to evaluate the potential therapeutic efficacy of sequential therapy with 153Sm-EDTMP, melphalan, and BMT. METHODS: Female C57BL/KaLwRij mice were inoculated with 8 x 10(5) 5T33 murine myeloma cells. Treatment protocols were begun 3 or 10 days later, when the myeloma was either confined to bone marrow or disseminated in liver, spleen, and lymph nodes, simulating human multiple myeloma. 153Sm, a potent beta particle-emitting radioisotope of short half-life (46.7 hours), was linked to the bone-seeking chelate EDTMP. Animals in the first treatment group were each given 22.5 MBq 153Sm-EDTMP via the jugular vein (day 3 or 10), followed by 18.5 mg/kg melphalan (maximum tolerated dose) given intraperitoneally 5 days later (day 8 or 15) and syngeneic BMT another 2 days later (day 10 or 17). Survival in groups of six to 10 animals for each time series was compared with that in mice left untreated (control cohort), in mice treated with 153Sm-EDTMP alone (day 3 or 10), or in mice treated with melphalan alone (day 8 or 15). The hematopoietic systems of animals in the latter two treatment groups recovered full function, obviating the necessity of BMT. The end point was onset of paraparesis, at which time the animals were immediately killed by carbon dioxide asphyxiation. RESULTS: Median survival in untreated control animals was 23 days in those with localized disease and 24 days in those with disseminated myeloma. Treatment with 153Sm-EDTMP alone improved survival to a median of 29 days when commenced on day 3 and 30 days when begun on day 10. Melphalan treatment alone improved the median survival to 31 days for animals with localized myeloma and 34 days in animals with disseminated disease. Additional improvement in survival to a median of 42 days was achieved in animals treated 3 days after tumor inoculation with sequential 153Sm-EDTMP, melphalan, and BMT; median survival was 40 days using this regimen in animals with disseminated myeloma. CONCLUSIONS: Animals in all three treatment protocols survived longer than those left untreated after inoculation with myeloma cells (P < .001). Sequential treatment with 153Sm-EDTMP, melphalan, and BMT was significantly more effective than single-agent treatment (P < .01). No evidence of radiotoxicity was detected in nonhematopoietic organs. IMPLICATIONS: The survival advantage conferred by our sequential treatment protocol suggests its potential clinical usefulness in the treatment of multiple myeloma and other hematologic malignancies in humans.

Animals↗

Tumor necrosis factor-alpha augments tumor effects in isolated hepatic perfusion with melphalan in a rat sarcoma model.

Isolated hepatic perfusion (IHP) is an attractive approach to treating nonresectable liver tumors, because the effects of systemic chemotherapy are poor and its application is hampered by severe general toxicity. In clinical and experimental settings, the efficacy of isolated limb perfusion (ILP) with tumor necrosis factor-alpha (TNF alpha) in combination with melphalan to treat melanoma in transit and soft-tissue sarcoma has been well established. In an ILP model in rats, the authors previously observed synergistic anti-tumor effects of TNF and melphalan on BN 175 soft-tissue sarcoma extremity tumors. The aim of the current study was to determine whether similar synergy in anti-tumor effects could be achieved by treating experimental BN 175 soft-tissue sarcoma liver tumors by IHP using these agents. The authors found that IHP with TNF and melphalan resulted in a dramatic increase in regional concentrations of perfused agents with virtually no concomitant systemic leakage. Isolated hepatic perfusion with only carrier solution resulted in a significantly diminished growth rate of BN 175 liver tumors compared with the growth rate of tumors in nonperfused rats. Perfusion with melphalan alone resulted in minimal anti-tumor effects. Perfusion with only TNF had a slight growth-stimulatory effect on the BN 175 liver tumors, but no negative effects on tumor growth were observed. When TNF was added to melphalan, a dramatic anti-tumor effect was observed. Thus, as in the rat ILP setting, the anti-tumor effect is augmented when TNF is added to IHP with melphalan to treat BN 175 soft-tissue sarcoma tumor-bearing rats. Strikingly, the tumor response was potentiated at relatively low concentrations of TNF compared with concentrations that elicited synergy with melphalan in ILP.

Adjuvants, Immunologic↗

Heat-mediated selective delivery of liposome-associated melphalan in murine melanoma.

Malignant melanoma is notable for its resistance to chemotherapy, and multimodality approaches are being investigated to improve therapeutic efficacy. Melphalan and dacarbazine are commonly used for treatment of melanoma and their effect is potentiated by hyperthermia. The present study attempts to enhance the antitumour effect of melphalan by encapsulating it in temperature-sensitive liposomes and using it in combination with localized hyperthermic treatment of tumours for targeted delivery. Small unilamellar vesicles made of synthetic lipids (distearoyl phosphatidyl choline and dipalmitoyl phosphatidyl choline), showing gel to liquid crystalline phase transition at 42 degrees C, were used for encapsulation of melphalan. In vivo antitumour efficacy of the combination of liposomal melphalan and hyperthermia was determined using B16F10 murine melanoma transplanted into C57Bl/6 mice. A significant reduction in tumour volume and increased survival time was observed in tumour-bearing mice treated with a combination of hyperthermia and thermosensitive liposome-encapsulated melphalan compared with animals treated with an equivalent dose of free melphalan with or without hyperthermia. These results suggest that hyperthermia in combination with temperature-sensitive liposome-encapsulated melphalan may serve as a useful targeted drug delivery system for more effective management of melanoma.

Animals↗