Showing papers in "Cancer Chemotherapy and Pharmacology in 1985"
TL;DR: A phase III 2x2 factorial trial of cisplatinum and bleomycin in 116 patients with recurrent or advanced squamous cell carcinoma of the head and neck foundThirty percent of patients proved to be unfit for chemotherapy, and of those treated progression of tumour was the commonest “response”.
Abstract: A phase III 2x2 factorial trial of cisplatinum and bleomycin in 116 patients with recurrent or advanced squamous cell carcinoma of the head and neck is reported.
118 citations
TL;DR: Clinical testing of some of the therapeutic possibilities for circumventing anthracycline resistance may soon be appropriate, following inherited changes in the cell membrane resulting in failure of drug accumulation.
Abstract: Resistance to anthracyclines is the major factor limiting their clinical utility. Laboratory studies using cultured experimental and human tumour cells have indicated that reduced intracellular drug accumulation is one important factor underlying resistance. In some systems this results from enhanced active drug efflux, a process which may be circumvented experimentally, for example by calcium antagonists. A specific glycoprotein which is produced in excess and is inherited has been identified in the cell membrane of certain anthracycline-resistant cells, while gene amplification with the appearance of double-minute chromosomes has been noted in others. Thus it is possible that anthracycline resistance arises following inherited changes in the cell membrane resulting in failure of drug accumulation. However, other possibilities exist, including differences in drug binding, either to the cell membrane or to nuclei, differences in metabolism to the semiquinone free radical, and differences in drug penetration related to tumour morphology. For each human tumour type the factor(s) involved may differ, but sufficient clues now exist to suggest that clinical testing of some of the therapeutic possibilities for circumventing anthracycline resistance may soon be appropriate.
110 citations
TL;DR: It is necessary to test these drugs in the assay by 24-h exposure for a more accurate assessment of their antitumor activity, as the effect of the schedule-dependent drugs was underestimated in the same conditions.
Abstract: To analyze the discrepancy between the in vitro response in the clonogenic assay and the clinical response, the time-schedule dependencies of various anticancer drugs were determined by comparing the inhibiting effect against colony formation by PC-7 cells treated with the drugs for 1 h with that of those treated for 24h. According to their schedule dependency the drugs can be divided into a schedule-dependent drug group (5-fluorouracil, methotrexate, bleomycin, pepleomycin, etoposide, cisplatin, teniposide, vindesine, and vinblastine) and a non-schedule-dependent drug group (adriamycin, actinomycin D, ranomustine, mitomycin C, aclacinomycin, daunomycin, nimustine, melphalan, and KW 2083). In the clonogenic assay, the 1-h exposure schedule is appropriate for predicting clinical response for the non-schedule-dependent drugs. However, the effect of the schedule-dependent drugs was underestimated in the same conditions. Therefore, it is necessary to test these drugs in the assay by 24-h exposure for a more accurate assessment of their antitumor activity.
94 citations
TL;DR: Melittin, which is a far more potent inhibitors of calmodulin activity, was also a more potent inhibitor of cell growth and clonogenicity, and the less active phenothiazine metabolite, chlorpromazine sulfoxide, had much less potent cytotoxic activity.
Abstract: Calmodulin, a ubiquitous calcium-binding protein, has recently been shown to play an important role in cellular proliferation. The calmodulin inhibitors melittin, trifluoperazine, and chlorpromazine inhibited the growth and clonogenicity of human and murine leukemic cells, and their potency reflected their activity as inhibitors of calmodulin. Melittin, which is a far more potent inhibitor of calmodulin activity, was also a more potent inhibitor of cell growth and clonogenicity. The less active phenothiazine metabolite, chlorpromazine sulfoxide, had much less potent cytotoxic activity.
80 citations
TL;DR: The lack of pharmacodynamic information is currently limiting the application of pharmacokinetic information to cancer therapy, and ways of improving knowledge of the pharmacodynamics of anticancer drugs are suggested.
Abstract: A considerable amount of information is available on the pharmacokinetics of anticancer drugs, but much less is known of their pharmacodynamics, that is of the relationship between therapeutic or toxic response and drug concentration. Drug dosage regimens which are to achieve defined therapeutic objectives can only be designed when both the pharmacokinetic and the pharmacodynamic characteristics of a drug are known. There are a few reports in the literature of relationships in man between toxic response and pharmacokinetic parameters of anticancer drugs; and an even smaller number of reports of relationships between therapeutic response and pharmacokinetic parameters. It is suggested that the lack of pharmacodynamic information is currently limiting the application of pharmacokinetic information to cancer therapy. Ways of improving knowledge of the pharmacodynamics of anticancer drugs are suggested.
72 citations
TL;DR: High-dose cyclophosphamide after conventional chemotherapy is feasible and achieves a high response rate, but it does not appear to be associated with significant survival benefit either overall or in patient subgroup.
Abstract: Whithin an original consecutive series of 94 patients, 36 eligible patients with small cell lung carcinoma were treated with high-dose cyclophosphamide 7 g/m2 after conventional chemotherapy with VP16, adriamycin, and vincristine. The first 17 also underwent autologous bone marrow rescue. Treatment was well tolerated apart from one treatment-related death. Measurable tumour was still present in 15 patients before high-dose cyclophosphamide, and although 12 (80%) of these achieved further tumour response, these responses were all short-lived, with a median duration of 9 weeks. In 14 limited-disease patients already in complete remission before high-dose therapy the initial result was better, but 11 (79%) have now relapsed following overall median response duration of 10 months. High-dose cyclophosphamide after conventional chemotherapy is feasible and achieves a high response rate, but it does not appear to be associated with significant survival benefit either overall or in patient subgroup.
65 citations
TL;DR: It is suggested that the kidneys of patients in the high-dose group were relatively protected by dilution of active Pt species in the urine in the tubule lumen as well as by high chloride ion concentrations in the urinary stream.
Abstract: Although nephrotoxicity has frequently limited conventional treatment with cisplatin to doses of 100-120 mg/m2 per cycle, vigorous chloruresis can permit the administration of high-dose cisplatin (200 mg/m2 per cycle) with minimal nephrotoxicity. Systemic toxicities are worsened, but therapeutic response seems to be enhanced. The pharmacokinetics of cisplatin in plasma and urine were examined to assess the causes of these effects. Plasma disappearance of ultrafiltrable platinum was well-described by a single exponential for each patient. The mean t1/2 was 50% longer for patients receiving high-dose cisplatin than for patients receiving conventional doses. The total systemic exposure was three times greater in the high-dose group, which tends to explain the systemic toxicity and improved tumor efficacy, but not the lack of nephrotoxicity. It is suggested that the kidneys of patients in the high-dose group were relatively protected by dilution of active Pt species in the urine in the tubule lumen as well as by high chloride ion concentrations in the urine.
63 citations
TL;DR: The experiments reported here suggest that polysorbate 80 has a direct effect on the blood-brain barrier leading to the increased uptake of MTX, which is evident following IV administration.
Abstract: This paper describes further exploration of the effect of polysorbate 80 on the absorption, distribution, and elimination of methotrexate (MTX). This study has confirmed the earlier finding that polysorbate 80 could increase the absorption of MTX from the mouse gastrointestinal tract and enhance the drugs uptake into the brain. The experiments reported here suggest that polysorbate 80 has a direct effect on the blood-brain barrier leading to the increased uptake of MTX, which is evident following IV administration. Measurements of MTX excreted in the urine and faeces confirmed the role of polysorbate 80 in facilitating the excretion of MTX into the bile and urine. Polysorbate 80 administered PO did not cause any reduction of plasma volume, thus excluding the possibility that the higher MTX concentrations measured in mice after concurrent administration of polysorbate PO might result from a reduction in blood volume due to osmotic effects. At the doses given, polysorbate 80 appeared not to have a damaging effect on the gastrointestinal mucosa.
55 citations
TL;DR: It is concluded that HPLC and TLC detect concentrations of doxorubicin andDoxorUBicinol from human plasma equally well to concentrations of 7.0 nM (4 pmol injected doxorbicin) and Aglycones do circulate in human plasma at concentrations above the detection limits of both assays.
Abstract: We compared doxorubicin and metabolite pharmacokinetic data obtained from thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) assay of plasma samples from six patients who had been treated with doxorubicin. Duplicate 1-ml samples were extracted with chloroform: isopropanol (1:1) and assayed using a sensitive HPLC system incorporating a dual pump gradient with tetrahydrofuran as the mobile phase and fluorescence detection. Duplicate 1-ml samples from the same specimens were assayed using a modification of a previously described TLC assay. Areas under the curve for doxorubicin by HPLC (3.36±2.30 μM · h) and TLC (4.16±2.50 μM · h) were not significantly different (P=0.5). Terminal half-life of doxorubicin by HPLC (28.0±6.98 h) and TLC (23.2±7.8) (P=0.29) and the calculated total-body clearances by HPLC (0.55±0.29 l/min) and TLC (0.45±0.23) (P=0.55) were not significantly different. Areas under the curve for doxorubicinol by HPLC (2.75±1.4 μM · h) and TLC (2.53±7.1 μM · h) (P=0.73) showed no significant differences. HPLC detected a mixed 7-deoxydoxorubicinol aglycone-doxorubicin aglycone peak, 7-deoxydoxorubicin aglycone, and two nonpolar, unidentified metabolites. TLC detected the following aglycone metabolites: doxorubicin aglycone, doxorubicinol aglycone, 7-deoxydoxorubicinol aglycone, an unidentified polar metabolite, and several unidentified nonpolar metabolites. From these data we conclude that HPLC and TLC detect concentrations of doxorubicin and doxorubicinol from human plasma equally well to concentrations of 7.0 nM (4 pmol injected doxorubicin). Aglycones do circulate in human plasma at concentrations above the detection limits of both assays. Doxorubicinol aglycone, which is detected by TLC but not by HPLC, may be formed from artifactual breakdown of doxorubicinol during TLC development. Unidentified nonpolar compounds seen on HPLC and TLC may represent further doxorubicin metabolism than previously described.
52 citations
TL;DR: In this paper, a number of potential problems associated with dissolving and storing drugs for in vitro use, which include drug adsorption, effects of freezing, drug stability under the normal conditions of dilution and setting up of an in vitro assay; and insolubility of drugs in normal saline (NS) or phosphate-buffered saline (PBS).
Abstract: In vitro drug sensitivity of tumour biopsies is currently being determined using a variety of methods. For these chemosensitivity assays many drugs are required at short notice, and this in turn means that the drugs must generally be stored in solution. There are, however, a number of potential problems associated with dissolving and storing drugs for in vitro use, which include (a) drug adsorption; (b) effects of freezing; (c) drug stability under the normal conditions of dilution and setting up of an in vitro assay; and (d) insolubility of drugs in normal saline (NS) or phosphate-buffered saline (PBS). These problems are considered in general, and some recommendations for use of solutions of drugs in in vitro assays are suggested. The nitrosoureas and alkylating agents are also investigated in greater detail in this respect. The nitrosoureas are found to be very labile in PBS at pH 7, with 5% degradation (t0.95) occurring in 10-50 min at room temperature. These values are increased about 10-fold on refrigeration and about 5- to 10-fold on reduction of the pH of the medium to pH 4-5. At pH 7 and room temperature, t0.95 is observed in under 1 h with the alkylating agents nitrogen mustard, chlorambucil, melphalan, 2,5-diaziridinyl-3,6-bis(2-hydroxyethylamino)-1,4-benzoquinone (BZQ), dibromodulcitol, dibromomannitol, treosulphan, and procarbazine. Of the other alkylating agents, 4-hydroperoxycylophosphamide (sometimes used in vitro in place of cyclophosphamide), busulphan, dianhydrogalactitol, aziridinylbenzoquinone (AZQ), and dacarbazine have a t0.95 of between 2 and 24 h, while ifosfamide and pentamethylmelamine are both stable in aqueous solution for greater than 7 days. About half the drugs studied in detail have been stored frozen in solution for in vitro use, although very little is known about their stability under these conditions.
51 citations
TL;DR: Future studies should test the possibility that ifosfamide-containing combination chemotherapy may be more effective than the regimens, usually including cyclophosphamide, that are currently used as front-line treatment of embryonal and Ewing's sarcoma.
Abstract: Twenty children with recurrent or unresponsive tumours (10 Wilms', 3 rhabdomyosarcoma, 4 Ewings's, 1 osteosarcoma, 1 hepatoblastoma, 1 hepatoma) and one untreated patient with renal carcinoma were given ifosfamide as a 24-h infusion (5 mg/m2), with mesna as uroprotective. The number of courses ranged from 1 to 13 (median 3), and the interval between them was 2–3 weeks. Sixteen of these patients had previously received cyclophosphamide. Complete clinical responses were seen in 3 cases (2 Wilms' and 1 Ewing's) and lasted 5, 7, and 9 months. Partial responses were seen in 3 instances, mixed response or stable disease in 4, and progressive disease in 11. Treatment was well tolerated in most patients, with no cystitis or severe myelosuppression, but 2 children developed transient neurological symptoms and 1 became hypertensive. Nausea and vomiting were controlled by high-dose dexamethasone in most children.
TL;DR: Calcium channel blockers verapamil diltiazem, nicardipine, and niludipine potentiated the antitumor activities of mitotic poison antitumors in P388 leukemia cells resistant to vincristine, suggesting the potential for therapeutic gain through the use of calcium channel blockers in combination with classic chemotherapeutic agents.
Abstract: The calcium channel blockers verapamil diltiazem, nicardipine, and niludipine potentiated the antitumor activities of mitotic poison antitumor agents, such as vincristine, vinblastine, vindesine, VP16-213, and taxol in P388 leukemia cells resistant to vincristine. The potentiating effect was generally dependent on the extent of cross-resistance seen in the cell line for these drugs. Calcium channel blockers also potentiate the antitumor activities of several DNA-interacting drugs, such as adriamycin, THP-adriamycin, daunomycin, aclacinomycin A, mitomycin C, actinomycin D, mitoxantrone, and nogalamycin derivatives in P388 leukemia resistant to adriamycin. Greater potentiation was observed for those antitumor agents to which the ADM-resistant cell line had become markedly cross-resistant, with the exception of the nogalamycin derivatives. Only a two-fold enhancement was observed for mitomycin C and aclacinomycin, as the cell line was only weakly cross-resistant to these agents. These results suggest the potential for therapeutic gain through the use of calcium channel blockers in combination with classic chemotherapeutic agents.
TL;DR: Comparison with data obtained in vitro and in mice showed that the nitrosourea exposures in these patients were at the lower limit of those required for significant antineoplastic activity.
Abstract: The plasma pharmacokinetics of orally administered CCNU (130 mg/m2) were studied in four patients using reversed-phase high-performance liquid chromatography (HPLC) analysis. Parent CCNU was not detected in the plasma of any of the patients, probably due to complete conversion to monohydroxylated metabolites during the ‘first pass’ through liver and gut. However, two monohydroxylated metabolites, trans-4-hydroxy CCNU and cis-4-hydroxy CCNU, were found at high concentrations, the relative amounts being about 6 : 4. Peak concentrations of the metabolites were reached 2–4 h after administration and were remarkably similar for all four patients, the total being 0.8–0.9 μg/ml. The metabolites were also detected in a tumour biopsy. Plasma clearance half-lives of the two metabolites were similar in each patient but showed a two-fold variation between patients, from 1.3 to 2.9 h. These results suggest that the antitumour activity and systemic toxicity of CCNU when given orally are due mainly to its monohydroxylated metabolites. Finally, comparison with data obtained in vitro and in mice showed that the nitrosourea exposures in these patients were at the lower limit of those required for significant antineoplastic activity.
TL;DR: This FAP combination appears to be as effective with respect to response rate and duration as reported for 5-fluorouracil, adriamycin and mitomycin C (FAM).
Abstract: Twenty patients (15 male, 5 female) with nonresectable gastric adenocarcinoma were treated with FAP (5-fluorouracil 300 mg/m2 IV on days 1–5, adriamycin 50 mg/m2 IV on day 1, cisplatin 20 mg/m2 IV on day 1–5). Each course was repeated every 21 days. Eighteen patients were evaluable for response. The median age was 51 years, the range extending from 34 to 68. None had undergone chemotherapy. The median Karnofsky performance score was 80%. Nine (50%) partial responses (PR) and eight (44%) cases of stable disease (SD) were observed. One patients showed progression of the disease and died after 6 months. The median duration of response was 6+ months for PR and 6 months for SD. The median survival was 12 months. FAP toxicity was moderate, with the median WBC nadir 3.2×109/l (range 0.7–4.2). One patient in PR died of septicemia. Nausea and vomiting were not dose-limiting. Neuropathy was mild in four and moderate in two patients. This FAP combination appears to be as effective with respect to response rate and duration as reported for 5-fluorouracil, adriamycin and mitomycin C (FAM).
TL;DR: Findings that calcium antagonists can increase the cytotoxicity of drugs in tumor cells with induced or inherent drug resistance by inhibiting outward transport of the drug indicate that calcium antagonist have potential as a new class of adjuvant agents in the field of cancer chemotherapy.
Abstract: Verapamil, a calcium antagonist, inhibited both experimental (IV inoculation of tumor cells) and spontaneous metastasis (SC inoculation) of the highly metastatic B16 melanoma and colon adenocarcinoma 26 cell lines. Verapamil treatment resulted in a maximum 80% inhibition of metastases, the degree of inhibition varying among the different metastatic systems. Verapamil inhibited platelet aggregation induced by these tumor cell lines, the patterns of inhibition being different for B16 melanoma and colon adenocarcinoma. The inhibition of platelet aggregation induced by tumor cells is proposed as a mechanism by which the calcium antagonist exerts its antimetastatic effect. These results, together with our previous findings that calcium antagonists can increase the cytotoxicity of drugs in tumor cells with induced or inherent drug resistance by inhibiting outward transport of the drug, indicate that calcium antagonists have potential as a new class of adjuvant agents in the field of cancer chemotherapy.
TL;DR: The production of 7-OH-MTX decreased significantly from the first to the last high-dose MTX cycle of the adjuvant chemotherapy protocol, and autostimulation of MTX metabolism leading to enhanced 7- OH- MTX production after repeated drug cycles was not observed.
Abstract: Kinetics of 7-hydroxy-methotrexate (7-OH-MTX) excretion after high-dose methotrexate (MTX) (12 g/m2) therapy were monitored in 93 consecutive drug cycles of 19 adolescent patients with osteosarcoma. A reversed-phase HPLC method was used. Serum elimination was found to be monophasic with a mean half-life of 5.5 h. Shortly after the 4-h MTX infusion period 7-OH-MTX levels exceeded those of the parent compound. By 12 h after MTX infusion 7-OH-MTX levels were 16.5 times higher than those of MTX itself. Autostimulation of MTX metabolism leading to enhanced 7-OH-MTX production after repeated drug cycles was not observed. The production of 7-OH-MTX decreased significantly from the first to the last high-dose MTX cycle of the adjuvant chemotherapy protocol.
TL;DR: These pharmacokinetic studies have shown that, by analogy with experimental systems, cytotoxic plasma levels of CB 3717 are archieved in man and have been valuable in interpreting toxicities observed during phase-I clinical studies.
Abstract: The pharmacokinetics of the new antifolate CB 3717 were studied in 20 patients during its phase-I clinical evaluation. The drug was administered at doses of 100–550 mg/m2 in 1-h and 12-h infusions, resulting in peak plasma concentrations of CB 3717 of 40–200 μM. There was a linear relationship between the dose and both CB 3717 AUC and peak plasma levels. Following a 1-h infusion, drug levels in the plasma decayed biphasically (t1/2α=49±9 min, t1/2β=739±209 min). 27%±2% of the dose was excreted in urine in the 24-h period after treatment, suggesting that the major route of elimination was via the bile. Furthermore, the parent compound CB 3717 and its desglutamyl metabolite, CB 3751, were found in a faecal collection although the metabolite was not detected in plasma or urine samples. Plasma protein binding of CB 3717 was extensive (97.6%±0.1%). Significant quantities of CB 3717 penetrated into ascitic fluid but not into cerebrospinal fluid.
TL;DR: Repeated administration of long-acting analogues of gonadotrophin-releasing hormone down-regulates the pituitary gonadOTrophins and gonadal hormones and suppression of these compounds in postmenopausal women with symptomatic advanced breast cancer is found.
Abstract: Repeated administration of long-acting analogues of gonadotrophin-releasing hormone down-regulates the pituitary gonadotrophins and gonadal hormones. The activity of these compounds in premenopausal women with breast cancer has been previously noted. In an attempt to cause a highly selective medical hypophysectomy 18 consecutive postmenopausal women with symptomatic advanced breast cancer were treated with intranasal buserelin in divided dosages of either 600 or 1000 μg daily. The pituitary gonadotrophins were suppressed in all patients, without objective evidence of response. This is in contrast with an earlier finding that the long-acting analogues of gonadotrophin-releasing hormone were effective in postmenopausal patients with breast cancer.
TL;DR: The reduction in the myeloid series in the bone marrow of gossypol-treated mice may have been due to depletion rather than direct toxic effect, and further studies are essential to evaluate this compound with regard to its antitumor activity in other murine models.
Abstract: Since the male antifertility drug, gossypol, was shown to be a specific inhibitor of DNA synthesis at moderately low doses in cultured cells, its antitumor potential has been evaluated in three murine tumor models. The effects of gossypol on tumor growth and the survival of 10-to 12-week-old BDF1 mice bearing mouse mammary adenocarcinoma 755 (Ca 755) or P388 or L1210 leukemias, all injected IP, were measured. At an optimum dose of 0.5 mg/mouse given as a single injection at 2 days (48 h) after the inoculation of 105 Ca 755 tumor cells, gossypol rendered 66% of the mice free of tumor cells, whereas the remaining 34% died of drug toxicity. The survival rate decreased sharply at doses on either side of the optimum. At suboptimal doses a major proportion of the tumor-bearing mice died of tumor, whereas at higher doses all the animals died of drug toxicity. In other words, the effective dose range of gossypol was rather narrow. The rapidly proliferating mouse leukemias, P388 and L1210, failed to respond to gossypol. Histopathological studies of various organs in the gossypol-treated mice revealed no consistent lesions that could give an indication of organ-specific toxicity of gossypol. The reduction in the myeloid series in the bone marrow of gossypol-treated mice may have been due to depletion rather than direct toxic effect. Further studies are essential to evaluate this compound with regard to its antitumor activity in other murine models.
TL;DR: The adrenal androgen androstenedione is the precursor of the main postmenopausal oestrogen, oestrone, and may constitute an important therapcutic effect of high-dose MPA.
Abstract: To investigate the mechanism of adrenal suppression by high-dose MPA, we performed direct and indirect stimulation tests in postmenopausal women with disseminated breast cancer who were receiving MPA and in a postmenopausal breast cancer control group. A partial adrenal insufficiency was found during Synacthen stimulation, confirmed by a slight increase of 11-desoxycortisol after metyrapone, despite a sufficient rise in ACTH levels. Peak levels of androstenedione and 17-OH progesterone after Synacthen correlated with those after metyrapone. Peak cortisol levels after Synacthen also correlated with the sum of cortisol and 11-desoxycortisol values after metyrapone, indicating the presence of a maximum adrenal response and a sufficient rise of endogenous ACTH after metyrapone. As the peak levels of cortisol and androstenedione were highly correlated with baseline values, a short Synacthen stimulation test may give a good indication as to whether adrenal suppression by MPA is adequate. The adrenal androgen androstenedione is the precursor of the main postmenopausal oestrogen, oestrone. In this way, adrenal suppression may constitute an important therapcutic effect of high-dose MPA.
TL;DR: It seems unlikely that the inhibition of ATP enzyme activity is the cause of nephrotoxicity, although cisplatin can affect ATPase activity.
Abstract: The effect of cisplatin on ATPase activity was determined in vitro and in vivo to investigate the correlation between nephrotoxicity and the inhibition of ATPase activity by cisplatin. Purified Na,K-ATPase was preincubated for 0–240 min with cisplatin at concentrations of 50–800 μM in vitro before the determination of enzyme activity. Although ATPase activity was reduced by cisplatin, either a high concentration of cisplatin (280 μM) or a long period of preincubation (160 min) with cisplatin was required to obtain 50% inhibition of ATPase activity. Similar in vitro experiments using kidney homogenate from female Sprague-Dawley rats instead of purified Na,K-ATPase were performed. Activity of Na,K-ATPase in rat kidney homogenate was inhibited by 50% after 110 min preincubation with 800 μM cisplatin or 160 min preincubation with 400 μM cisplatin. Female Sprague-Dawley rats were given 5, 7 or 10 mg/kg of cisplatin IV and BUN level, ATPase activity and Pt concentration in kidney homogenate were evaluated 1 h, 6 h, 1 day, 3 days, and 5 days after cisplatin injection. In rats given 10 mg/kg cisplatin a significant increase of BUN was observed on days 1, 3, and 5. In rats treated with 5 or 7 mg/kg of cisplatin BUN was increased on days 3 and 5. Normal ATPase activity, however, was preserved until day 3 at all doses. The highest concentration of Pt observed in kidney tissue was 19.3 μg/g tissue. This value was insufficient to inhibit ATPase activity significantly in vitro. Thus, it seems unlikely that the inhibition of ATPase activity is the cause of nephrotoxicity, although cisplatin can affect ATPase activity.
TL;DR: The results suggest that increased uptake and retention by both MRA and MRA-CN may contribute to their increased cytotoxicity, but that the intense potency of the cyano-morpholinyl analogs must be due to other unique properties of these compounds.
Abstract: A series of quinone- and sugar-modified analogs of adriamycin have been tested for growth inhibition of adriamycin-sensitive (P388/S) and -resistant (P388/ADR) sublines of P388 murine leukemia cells in vitro. P388/ADR is less resistant to analogs of adriamycin containing either a 3′-deamino-3′-(4″-morpholinyl) group, MRA; or a-(3″-cyano-4″-morpholinyl) group, MRA-CN, than to adriamycin. However, MRA-CN was the most potent growth inhibitor of either subline. This potency is reduced by either modification of the quinone unit with a 5-imino substituent or restriction of the cyano-morpholinyl ring by an oxygen bridge to the daunosamine sugar. The calcium antagonist verapamil substantially increases the cytotoxicity of adriamycin to P388/ADR but has no appreciable effect on the cytotoxicity of either MRA or MRA-CN. The results suggest that increased uptake and retention by both MRA and MRA-CN may contribute to their increased cytotoxicity, but that the intense potency of the cyano-morpholinyl analogs must be due to other unique properties of these compounds.
TL;DR: The narrow therapeutic index of the BOM therapy makes it a less than ideal drug combination for the treatment of advanced squamous cell carcinoma of the anal canal.
Abstract: Fifteen patients with advanced squamous cell carcinoma of the anal canal were treated with a combination of bleomycin, vincristine, and high-dose methotrexate (BOM) with leucovorin rescue. Three out of twelve patients with measurable disease had objective responses of 1, 2, and 5 months. Five of the fifteen patients had severe or life-threatening complications as a result of this treatment regimen. The narrow therapeutic index of the BOM therapy makes it a less than ideal drug combination for the treatment of advanced squamous cell carcinoma of the anal canal.
TL;DR: The results indicate that the sensitivity of different cell lines to HT may be related to the degree of HT binding; and the effects of HT are more dependent on exposure time than concentration.
Abstract: Ten human leukemia-lymphoma cell lines were tested for the growth-inhibitory effects of harringtonine (HT). HT was most active against HL-60 acute promyelocytic leukemia cells and least active against DND-41 acute lymphoblastic leukemia cells, with a 70-fold differential activity. Sensitivity of the cell lines is, in decreasing order: HL-60 > RPMI-8402 > DND-39A ≃ ML-2 ≃ MOLT-3 ≃ KG-1 > Daudi ≃ NALL-1 > BALM-2 > DND-41. The cell lines with rapid cell growth tended to be more sensitive to HT. To further elucidate the selectivity of the differential sensitivity, uptake and release of HT were compared in HL-60 and DND-41 cells. Uptake of [3H]HT into HL-60 and DND-41 cells showed no difference; however, the binding of [3H]HT to cellular components was > 16-fold higher in HL-60 cells than DND-41 cells. There were also minor, but significant differences in the inhibition of [3H]leucine incorporation into proteins of these two cell lines in the presence of 1 μg/ml HT. To test whether the biological effects of HT are related to the concentration of, or exposure time to, HT, KG-1 cells were exposed to HT for different periods of time and the growth-inhibitory effects were compared. Increasing exposure time from 1 h to 3 h resulted in a 100-fold decrease in concentration x exposure time (c x t) at ID50; from 3 h to 6 h, in a 20-fold decrease at ID70; and from 6 h to 24 h, in a 16-fold decrease at ID90. HT was not inactivated by cells up to 24 h. These results indicate that (a) the sensitivity of different cell lines to HT may be related to the degree of HT binding; and (b) the effects of HT are more dependent on exposure time than concentration. Continuous infusion is thus rational for clinical trials of this drug, and the degree of HT binding to leukemic cells may be predictive of clinical response.
TL;DR: Evidence is presented that rabbits were almost completely protected against both BUN increase and body weight loss normally caused by DDP when 400-fold doses of STS were given, and that this protective effect is due to inactivation of biologically active DDP in the bloodstream.
Abstract: The mode of inactivation of cis-diamminedichloroplatinum(II) (DDP) in the bloodstream and protection from its toxicity by sodium thiosulfate (STS) were investigated in rabbits. Plasma ultrafiltrate in rabbits given 5 mg/kg DDP IV and various excess molar ratios of STS IV were assayed for the active platinum levels with a new microbiological assay system using an E. coli strain. The active platinum species in the plasma were inactivated completely by coadministration of a 400-fold excess of STS IV. The rabbits were almost completely protected against both BUN increase and body weight loss normally caused by DDP when 400-fold doses of STS were given. Diuretic effects were also observed. Our data provide evidence for the basis of optimum use of STS to protect against DDP toxicity. [6, 9]. This TRC with DDP and STS is now in clinical trial [7, 8], but the precise mode of protective action of STS against DDP toxicity has not been determined. We now present evidence that this protective effect is due to inactivation of biologically active DDP in the bloodstream.
TL;DR: The results suggest that renal clearance of ultrafilterable platinum is probably dependent on cis-DDP dose, urine flow rate, and individual variability in the extent of active secretion and tubular reabsorption.
Abstract: Nonlinear renal clearance of ultrafilterable platinum was observed in 5 of 7 patients given cis-dichlorodiammineplatinum (II) in doses of 50-140 mg/m2 by short-term infusion (2 h). Average renal clearance determined during and 24 h after infusion ranged from 100 to 543 ml/min and always exceeded creatinine clearance, suggesting that ultrafilterable platinum was renally secreted. Saturable tubular reabsorption was postulated on the basis that renal clearance was highest at peak plasma and urinary levels and fell as the levels declined. Although an overall relationship between dose and renal clearance was not apparent, one patient receiving the highest dose (140 mg/m2) had elevated average renal clearance (485 ml/min), probably associated with saturation of reabsorption, whereas a patient receiving 50 mg/m2 had the lowest average renal clearance (100 ml/min), indicating that either active secretion was lower, or tubular reabsorption was saturated. One patient also showed urine-flow-dependent changes in renal clearance. Four patients had transient rises in ultrafilterable platinum levels, which were attributed to changes in renal tubular reabsorption. The results suggest that renal clearance of ultrafilterable platinum is probably dependent on cis-DDP dose, urine flow rate, and individual variability in the extent of active secretion and tubular reabsorption. A sensitive HPLC method was applied and ultrafilterable platinum was detected in the plasma of all patients 24 h after infusion. Renal tubular reabsorption may result in prolonged plasma levels of ultrafilterable platinum, which could contribute to the drug's antitumour effect.
TL;DR: The ability of purified protein A (P) of Staphylococcus aureus to reduce Cy-induced toxicity in rats is described for the first time and may prove to be an effective agent in increasing the therapeutic index of Cy.
Abstract: Cyclophosphamide (Cy) is widely used as an effective cytotoxic drug, but its use is limited because of its toxicity. In this report, we describe for the first time the ability of purified protein A (P) of Staphylococcus aureus to reduce Cy-induced toxicity in rats. Protein A-treated animals recover quickly from the toxic effects of Cy. The antitumor property of Cy is not reduced in the P+Cy group. In fact, the latter showed a persistent decrease in tumor volume compared with the Cy group. Protein A may prove to be an effective agent in increasing the therapeutic index of Cy.
TL;DR: In this assay the chemosensitivity in specimens from ovarian cancer patients who had had prior chemotherapy was significantly lower than in those from nonpretreated patients, which seems to indicate the development of drug resistance after treatment with anticancer drugs.
Abstract: The efficacy of anticancer drugs against ovarian cancer, breast cancer, and colorectal cancer has been evaluated in vitro by the human tumor clonogenic assay developed by Hamburger and Salmon. The in vitro colony assay method used in this study is a minor modification of their method and was used in 83 patients with ovarian cancer, 47 patients with breast cancer, and 13 patients with colorectal cancer. The total numbers of assays performed in vitro were 258 for ovarian cancer, 87 for breast cancer, and 38 for colorectal cancer. The average chemosensitivity rates to single agents tested were 35% and 32% in the untreated patients with ovarian and breast cancer, respectivety. In contrast to this result, the chemosensitivity rate of the untreated patients with colorectal cancer was only 16%. Consisting the clinical efficacy of anticancer drugs against these tumors, these results suggest that there is a correlation between chemosensitivity in the human tumor clonogenic assay and clinical responsiveness. In this assay the chemosensitivity in specimens from ovarian cancer patients who had had prior chemotherapy was significantly lower than in those from nonpretreated patients (P0.05). This seems to indicate the development of drug resistance after treatment with anticancer drugs. These results suggest that the human tumor clonogenic assay is a useful tool for the evaluation of antitumor effects of drugs in vitro.
TL;DR: Preliminary pharmacokinetic data for etoposide together with calibration data are presented, and are discussed with reference to the sensitivity and detection limit of the new experimental methods.
Abstract: Drug monitoring is performed by means of sample extraction, sample purification by high-performance liquid chromatography (HPLC), and sample detection by time-of-flight mass spectrometry. This mass spectrometry utilizing 252Cf fission fragment-induced ionization and desorption of nonvolatile compounds is suitable as a universal, nondestructive detector in HPLC. Liquid chromatography and mass spectrometry are combined, so that mass analysis can be operated online and offline to the fractional sampling of the effluent and the samples can still be recovered.
TL;DR: It is suggested that bleomycin-induced damage to the pulmonary capillary vasculature can be monitored by measuring Vc and that ensuing fibrosis can be measured by recording Dm.
Abstract: Pulmonary function tests, including spirometry, transfer factor of the lungs for carbon monoxide (TlCO), and the two components of TlCO, the diffusing capacity of the alveolocapillary membrane (Dm) and pulmonary capillary blood volume (Vc), were carried out in a group of patients with testicular carcinoma during and after treatment with the Einhorn regimen. The lung function parameters of patients who developed bleomycin-induced pneumonitis were compared with those recorded in a group of patients who did not develop this syndrome. We suggest that bleomycin-induced damage to the pulmonary capillary vasculature can be monitored by measuring Vc and that ensuing fibrosis can be measured by recording Dm. The decrease in Dm is probably compensated for by an increase in Vc, leading to a smaller change in TlCO.