Differentiation therapy of cancer: laboratory and clinical investigations.
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Cell Differentiation↗
Biomedical subjects
C W Young
Publications and source records attributed to C W Young.
Lipid hydroperoxides greatly increase the rate of oxidative catabolism of all-trans-retinoic acid by human cell culture microsomes genetically enriched in specified cytochrome P-450 isoforms.
Cytochrome P-450 enzymes have been implicated in the oxidative catabolism of all-trans-retinoic acid (RA), a process that is accelerated by exposure to RA in cultured cells and rodents, and also in patients receiving RA as treatment for cancer (J.F.R. Muindi et al., Cancer Res., 52: 2138, 1992; Blood, 79: 299, 1992). Accelerated oxidation of RA could arise from an induction of RA-catabolizing P-450 isoforms or from an increase in oxidative cofactors. We have examined the efficiency of NADPH/O2 and lipid hydroperoxides (LOOH) to support oxidation of RA using human cell microsomes genetically enriched in different P-450 isoforms. The observed rate of RA oxidation using the NADPH/O2 system was slow for all isoforms (6-23 pmol/mg protein/min). LOOH-mediated oxidation was much faster (24-1078 pmol/mg protein/min), not isoform specific, but dependent upon the chemical nature of the LOOH. The order of efficiency of RA oxidation using LOOH was 13-hydroperoxy[S-(E,Z)]-9,11-octadecadienoic acid > 5-hydroperoxy[S-(E,Z,Z,Z)]-6,6,11,14-eicosatetraenoic acid > prostaglandin G2 > cumene hydroperoxide > tert-butylhydroperoxide > H2O2. Whereas submicromolar concentrations of 13-hydroperoxy[S-(E,Z)]- 9,11-octadecadienoic and 5-hydroperoxy[S-(E,Z,Z,Z)]-6,6,11,14- eicosatetraenoic acid oxidized RA at appreciable rates, micromolar concentrations were required for the other LOOH. These observations suggest that physiological LOOH, generated by the arachidonic acid-lipoxygenase system, may be involved in the self-induced oxidative catabolism of RA.
Carrier Proteins↗
Edatrexate, an antifolate with antitumor activity: a review.
Edatrexate (10-ethyl, 10-deaza-aminopterin; 10-EdAM) is one of a group of compounds developed by substitutions at the N10-position of 4-aminofolate. In phase I and II trials, activity has been seen against non-small-cell lung cancer, breast cancer, non-Hodgkin's lymphoma, and cancer of the head and neck. In preclinical studies, a synergistic effect has been reported when edatrexate is combined with other antineoplastic drugs, and enhanced activity has been seen in two combination-chemotherapy phase II studies in patients with non-small-cell lung cancer. In in vivo preclinical studies, edatrexate has demonstrated antitumor activity against mouse solid and ascites tumors as well as human tumor xenografts. The activity is superior to that of methotrexate and the other antifolates tested. The improved therapeutic index of edatrexate appears to be related to its increased entry into, and polyglutamylation within, tumor cells, and its relative exclusion and rapid elimination from sensitive host tissues, compared to methotrexate. Edatrexate is metabolized in the liver and then excreted mainly in the bile. In clinical trials in cancer patients, the dose-limiting and most frequent toxicity is mucositis. Other side effects are generally mild and include myelosuppression, nausea, vomiting, elevations in SGOT, and macular rash. The responses seen in clinical trials along with preclinical data suggest that edatrexate may be a valuable agent in the treatment of cancer. Studies currently underway include the evaluation of edatrexate in small-cell lung cancer and edatrexate in combination with leucovorin, new vinca alkaloids, and cisplatin.
Aminopterin↗
Phase I clinical and pharmacological study of chloroquinoxaline sulfonamide.
Chloroquinoxaline sulfonamide (CQS) is a halogenated heterocyclic sulfanilamide identified by the in vitro human tumor colony-forming assay as an active agent in a variety of human solid tumors. In this phase I study, 182 courses of CQS were administered intravenously every 28 days to 88 patients at doses ranging from 18 to 4870 mg/m2. Hypoglycemia associated with hyperinsulinemia was the dose-limiting adverse effect at 4870 mg/m2. Supraventricular tachyarrhythmias were observed at doses > 4000 mg/m2. Less common reactions included infusion site phlebitis, nausea, anemia, alopecia, perioral numbness, and diarrhea. Cumulative toxicity was not observed. Minor objective antitumor responses were noted in 7 patients; 6 of the 7 responses occurred in patients with non-small cell lung cancer. Results of pharmacokinetic studies were consistent with the preclinical observations that CQS is highly bound to plasma protein. Plasma elimination followed a two-compartment model; the mean t 1/2 alpha was 2.7 +/- 0.3 h and the t 1/2 beta was 52 +/- 6 h (+/- SE). The total body clearance and the volume of distribution at steady state of CQS both increased with the dose (distribution at steady state, 3.7-10.5 liter/m2; total body clearance, 53-264 ml/h/m2 for doses of 18-4060 mg/m2) and may reflect saturation of the protein binding and "free" drug clearance. Although inactive against common animal tumors in preclinical screening systems both in vitro and in vivo, CQS has demonstrated definite activity in the human tumor stem cell colony-forming assays, as well as modest anticancer activity in this phase I study in patients with advanced solid tumors. The pharmacokinetic results and the limiting effect of transient hypoglycemia suggest that considerably higher cumulative doses of CQS could be administered using a more frequent dosing schedule.
Adult↗
Hexamethylene bisacetamide in myelodysplastic syndrome and acute myelogenous leukemia: a phase II clinical trial with a differentiation-inducing agent.
Hexamethylene bisacetamide (HMBA) is a potent inducer of differentiation of a number of transformed cell lines in vitro. We report results of a phase II clinical trial in 41 patients with myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML) to whom HMBA was administered by continuous infusion for 10 days and repeated after an interval of 18 to 75 days. HMBA induced a complete remission (CR) in three patients and a partial remission (PR) in six patients. The median duration of CR was 6.8 months (range 1.3 to 16 months) and 3.7 months for PR (range 1 to 7 months). No significant difference was observed between responders and nonresponders with respect to the mean HMBA plasma levels, which were 0.86 +/- 0.04 mmol/L and 0.87 +/- 0.12 mmol/L, respectively. In certain patients morphologic and chromosome analyses provided evidence that HMBA induced differentiation of transformed hematopoietic precursors. The most prominent toxicity was thrombocytopenia, generally reversible on cessation of administration of HMBA.
Acetamides↗
Clinical pharmacology of oral all-trans retinoic acid in patients with acute promyelocytic leukemia.
All-trans retinoic acid (RA) induces leukemic cell differentiation and complete remission in a high proportion of patients with acute promyelocytic leukemia (APL). However, remissions induced by all-trans RA tend to be brief, and relapses are associated with resistance to further treatment in vivo, although the leukemic cells appear to retain sensitivity to the cytodifferentiating effects of all-trans RA in vitro. The clinical pharmacology of all-trans RA was examined in 13 patients with APL. The drug was administered at a constant dose of 45 mg/m2/day, given as a single dose on the first day of therapy and in two divided doses thereafter. Plasma and urinary concentrations of the parent drug and metabolites were quantitated by reverse-phase high-performance liquid chromatography and, where required, by a combination of normal-phase liquid chromatography/negative chemical ionization mass spectrometry. In patients with APL, basal levels of endogenous retinol and natural retinoids were within the normal range. Peak plasma levels of all-trans RA (347 +/- 266 ng/ml, mean +/- SD) were reached 1-2 h after drug ingestion and decayed in a monoexponential fashion with a half-life of 0.8 +/- 0.1 h. The only drug metabolite detected in plasma or urine was 4-oxo-all-trans RA (present in urine as the glucuronide conjugate). This metabolite accounted for less than 10% of the circulating drug in plasma, and its cumulative urinary excretion accounted for less than 1% of the administered dose. The drug was not found in cerebrospinal fluid. Continued oral administration of all-trans RA was associated with a significant decrease in both the plasma peak levels and the area under the concentration-time curve (P = 0.01 and 0.004, respectively) when measured after 2-6 weeks of treatment. We previously reported that a decrease in plasma area under the concentration-time curve was highly correlated with clinical relapse. Observations in a subset of patients in this study suggested that, in fact, the major decrease occurred early, within the first 7 days of treatment. These changes were associated with a 10-fold increase in urinary excretion of 4-oxo-all-trans RA glucuronide, suggesting that the accelerated clearance from plasma was associated with increased drug catabolism. The rapid disappearance may explain early relapse from remissions induced by all-trans RA; clinical "resistance" to all-trans RA may either wholly or in part result from an inability to sustain effective plasma concentrations of all-trans RA during continuous treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
Administration, Oral↗
Continuous treatment with all-trans retinoic acid causes a progressive reduction in plasma drug concentrations: implications for relapse and retinoid "resistance" in patients with acute promyelocytic leukemia.
Although all-trans retinoic acid (RA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL), all groups have described clinical relapses despite continued RA treatment. This finding suggests that resistance to the cytodifferentiating effects of the retinoid had been acquired. To investigate potential mechanisms of clinical resistance to RA, we serially evaluated the clinical pharmacology of the drug in APL patients treated with this agent. Leukemic cells from patients relapsing from RA treatment were cultured in the presence of RA and examined for evidence of morphologic maturation. We also studied messenger RNA expression of the newly described gene product of the (15;17) translocation in APL, PML/RA receptor-alpha (PML/RAR-alpha). Serial pharmacokinetic studies showed that continuous daily RA treatment was associated with a marked decrease in plasma drug concentrations at the time of relapse compared with the initial day of therapy. Doubling the RA dose in six patients failed to reinduce response at the time of relapse and also failed to significantly augment plasma RA concentrations. However, leukemic cells obtained at the time of relapse from four patients retained in vitro sensitivity to the differentiating activity of RA (10(-6) mol/L). No change was observed in the pattern of PML/RAR-alpha expression assessed by Northern blot analysis at the time of relapse compared with pretreatment in two patients who were tested. These results indicate that clinical relapse and "resistance" to continuous treatment with all-trans RA in APL is associated with progressive reduction of plasma concentrations, potentially to levels below those that sustain differentiation of leukemic cells in vivo. Long-term success of this treatment will require the development of strategies that circumvent this pharmacologic phenomenon.
Carrier Proteins↗
Postoperative inflammation following cataract extraction caused by bacterial contamination of the cleaning bath detergent.
Five of 16 patients who had uncomplicated cataract extraction with intraocular lens (IOL) implantation within a 2.5 day period experienced increased anterior segment inflammation on their first postoperative day. Four of these five patients had phacoemulsification and one a planned extracapsular cataract extraction. All had posterior chamber IOL implantation in the capsular bag. In all patients, this anterior segment inflammation cleared with topical steroids over two to three weeks with no evident residual ocular effects. A careful search for the possible cause of the inflammation showed that the ultrasonic cleaning bath and Weck liquid detergent used to clean the instruments contained Klebsiella pneumoniae bacteria. Further investigation demonstrated the presence of a heat-stable endotoxin produced by the bacteria. We postulate that endotoxin remaining on the instruments after cleaning and sterilization caused this postoperative anterior segment inflammation. To the best of our knowledge, these are the first reported cases caused by contaminated liquid detergent.
Aged↗
Clinical pharmacology of deoxyspergualin in patients with advanced cancer.
Pharmacokinetic studies were carried out in 25 patients with advanced cancer receiving deoxyspergualin (DSG), a candidate anticancer agent, in a dose-finding Phase I study. The dosage range explored was 80 to 2160 mg/m2/day for 5 days by continuous i.v. infusion. The drug levels in plasma and urine were measured by high-performance liquid chromatography with postcolumn derivatization and fluorescence detection. One drug metabolite was demonstrated in plasma and urine of treated patients. This metabolite was extracted from urine and purified to homogeneity; thereafter, it was examined by high-performance liquid chromatography, nuclear magnetic resonance, and fragmentation mass spectrometry and was demonstrated to be identical to chemically synthesized desaminopropyl-DSG. The mean steady state plasma concentrations of DSG ranged from 0.28 to 11.1 microM at, respectively, the 80- and 2160-mg/m2 dosage levels. The plasma concentration at steady state and the area under the plasma concentration versus time curve of DSG were proportional to dose (r = 0.97). Following discontinuance of the infusion, DSG was cleared from the plasma in a biexponential fashion. The mean total body clearance was 364 +/- 78 ml/min/m2. Desaminopropyl-DSG was formed extensively at all dosage levels; mean steady state plasma levels of this metabolite reached a plateau 2.65 microM at a dose of 720 mg/m2/day and did not rise with further dose increments. The urinary content of DSG was examined in 20 patients over the dosage range from 160 to 960 mg/m2/day; in this group less than 10% of the administered dose was excreted as DSG. In four patients at the 720- and 960-mg/m2/day dosage levels, the total DSG plus metabolite excretion ranged from 7 to 18% of the administered dose, with comparable quantities occurring as the parent drug and desaminopropyl-DSG.
Animals↗
In vivo monitoring of changes in 5-fluorouracil metabolism induced by methotrexate measured by 19F NMR spectroscopy.
We have used in vivo 19F NMR spectroscopy to study the metabolism of 5-fluorouracil (FUra) in tumors with and without pretreatment with methotrexate (MTX). Using the CD8F1 murine mammary tumor as an in vivo model, we observed signals from FUra, alpha-fluoro-beta-alanine (F beta ALA), alpha-fluoro-beta-ureidopropionic acid (FUPA), and 5-fluorouracil-nucleotides (FUN) after intravenous or intraperitoneal injection of 150 mg/kg FUra. Formation of FUN was increased about 1.7-fold in CD8F1 tumor with methotrexate pretreatment as determined by acid extraction and HPLC analysis. A comparison of in vivo NMR spectra from FUra and sequential MTX + FUra-treated tumors showed a significantly higher ratio of the FUN signal to the initial total 19F signal in the MTX + FUra-treated tumors (p less than 0.001) for animals receiving FUra either intravenously or intraperitoneally. In addition, tumors treated with MTX + FUra had significantly longer time durations during which FUN was detected, independent of the mode of administration. These experiments indicate that in vivo 19F NMR spectroscopy can be used to noninvasively monitor alterations of 5-fluorouracil metabolism that occur with administration of modulating agents such as methotrexate. Further studies, in both murine tumor models and patients, are indicated to determine if these results can be correlated with tumor response.
Animals↗
Motor activity of squirrel monkeys measured with an ultrasonic motion sensor.
We describe an ultrasonic motion sensing system for measuring the motor activity of individual squirrel monkeys in their home cage. The system utilizes an inexpensive Commodore 64 microcomputer for data collection and can distinguish between movements of short (i.e., less than 1.0 s) and longer (i.e., greater than or equal to 1.0 s) duration, and between number of movements and time spent in motion. The diurnal pattern of spontaneous activity is illustrated along with the dose-dependent effects of d-amphetamine (0.025-1.6 mg/kg) and haloperidol (0.025-0.4 mg/kg).
Animals↗
Calving disorders of primiparous Holsteins from designed selection studies.
Primiparous Holsteins from designed studies were evaluated for edema, dystocia, and retained placenta. Genetic studies were 1) selection for large body size versus small body size, and 2) milk yield selection versus control (no selection). The large body size group was mated to sires with extreme estimates of transmitting ability for tall height and deep and wide bodies. Small body size group was mated to extreme sires for transmitting short height and shallow, narrow bodies. Large and small cows significantly differed only for edema, and small cows had scores suggesting more severe udder edema than large cows. Milk selection group was mated to the four highest sires for PTA milk each year, whereas a control group was mated to 20 randomly selected AI sires that were breed average for PTA milk in 1964. Selection groups for milk yield did not differ significantly for any of the calving disorders.
Age Factors↗
The combined use of radiation therapy and lonidamine in the treatment of brain metastases.
Lonidamine is an indazole carboxylic acid that has been shown to be synergistic with radiotherapy (RT) in tissue culture and animal models. Clinical experience has shown that lonidamine is well-tolerated, and appears to potentiate the activity of conventional chemotherapy in the treatment of brain metastases. A prospective randomized trial was undertaken to evaluate the use of lonidamine in combination with RT in the treatment of brain metastases. All patients received 3000 cGy of whole brain radiotherapy (WBRT). Fifty eight patients were enrolled; 31 received lonidamine plus WBRT and 27 received WBRT alone. There was no significant difference in response rate or survival between the treatment groups. Lonidamine blood levels were measured in 30 of the 31 patients who received the drug, and were therapeutic (greater than or equal to 15 micrograms/ml) in 50%. Survival and response rate were unaffected by the presence or absence of a therapeutic lonidamine level. The most common side-effects of lonidamine were myalgia, testicular pain, anorexia, and ototoxicity; however, only 2 patients had to discontinue the drug because of intolerable myalgias. No serious organ toxicity or myelosuppression was observed.
Adult↗
Induction of profound hypouricemia by a non-sedating thiobarbiturate.
5-[N-phenylcarboxamido]-2-thiobarbituric acid (merbarone) is a non-sedating derivative of thiobarbituric acid originally developed for anticancer use. In the initial clinical study, a profound reduction in serum uric acid was observed. In 20 patients who received five daily doses of merbarone ranging from 100 to 750 mg/m2, serum uric acid concentration was reduced from a mean pretreatment value of 5.7 +/- 1.6 mg/dL to a mean lowest value of 1.3 +/- 0.5 mg/dL. In most patients, the onset of the effect occurred with 24 hours and was maximal by 48 to 72 hours. Metabolic studies in two patients showed an increase in urinary uric acid excretion within 24 hours after initiation of drug treatment. A marked increase in fractional excretion of uric acid was sustained throughout the period of drug treatment. Urinary excretion of total oxypurines (xanthine and hypoxanthine) was increased twofold to threefold relative to baseline levels. Ultrafiltration studies showed that merbarone did not significantly displace binding of urate from albumin. When merbarone was incubated with xanthine oxidase in vitro, several reaction products were observed, including 2-oxo-2-desthio-merbarone and a compound with retention time similar to 4'-OH-merbarone. Both of these compounds have been described previously as metabolites of merbarone in human subjects. The parent drug and both metabolites were found to inhibit xanthine oxidase (Ki = 41, 36, and 240 mumols/L, respectively). However, this inhibitory effect was substantially less potent than allopurinol (Ki = 0.025 mumols/L). This study indicates that merbarone induces profound hypouricemia primarily by increasing uric acid excretion.(ABSTRACT TRUNCATED AT 250 WORDS)
Antineoplastic Agents↗
Potentiation of radiation effects on multicellular tumor spheroids (MTS) of HeLa cells by lonidamine.
Lonidamine is a potent inhibitor of spermatogenesis and a hyperthermic sensitizer. The previous study of lonidamine and radiation using two murine tumors demonstrated that tumor cure rates were significantly increased by radiation and concomitant lonidamine. In an effort to determine the radiobiologic factors involved with the potentiating effect of radiation by lonidamine, a series of cell culture studies were carried out using multicellular tumor spheroids (MTS) of HeLa Cells. When the MTS were treated with lonidamine in combination with fractionated irradiation, remarkable enhancement of growth inhibition was observed at the drug concentration of 10 micrograms/ml. On the other hand, there was no demonstrable enhancement of growth inhibition induced by a single dose of irradiation. Although the present findings would be consistent with the inhibitory action of potentially lethal damage repair of radiation by the drug, an alternative possibility is that the cells that have received the combined treatment have undergone a metabolic change, which has altered their sensitivity to the growth inhibitory effects of lonidamine. Based on the studies reported here and in mice, it is suggested that continued drug exposure over a prolonged period may provide an enhanced therapeutic effect, even in tumor varieties where the drug has no apparent antitumor activity on nonirradiated cells.
Cell Aggregation↗
Dose-ranging antiemetic trial of high-dose oral metoclopramide.
The present trial with high oral doses of metoclopramide was undertaken to (a) determine a well-tolerated dosage of oral metoclopramide; (b) measure the blood levels achieved with these oral doses; (c) determine the side effects of high doses; and (d) observe for antiemetic efficacy. Thirty-six patients receiving emesis-producing chemotherapy consisting primarily of high intravenous (i.v.) doses of cyclophosphamide plus adriamycin or cisplatin received 48 courses of oral metoclopramide. The metoclopramide dosage was escalated in six steps from 0.5 to 3.0 mg/kg and was given 1/2 h before chemotherapy, then 1 1/2, 3 1/2, 7 1/2, 11 1/2, and 15 1/2 after chemotherapy. Diphenhydramine (50 mg orally) was given with the first, third, and fifth dosages. Toxicity was generally mild, not dose related, and similar to that observed with the i.v. drug with the exception of an increased incidence of acute dystonic reactions. Antiemetic effects were observed at each dose level. In patients receiving oral metoclopramide doses of 2 or 3 mg/kg, all achieved serum levels greater than 1,000 ng/ml. High-dose oral metoclopramide was well tolerated and demonstrated antiemetic effects at the dose levels explored. We recommend 2-3 mg/kg oral metoclopramide doses with 50 mg diphenhydramine for use in future trials.
Administration, Oral↗
Idarubicin in acute leukemia: results of US trials.
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Antineoplastic Combined Chemotherapy Protocols↗
Idarubicin in acute leukemia: results of studies at Memorial Sloan-Kettering Cancer Center.
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Adolescent↗