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Sökning: WFRF:(Hassan Saadia)

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  • Gullbo, Joachim, et al. (författare)
  • Antitumor efficacy and acute toxicity of the novel dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) in vivo.
  • 2004
  • Ingår i: Investigational new drugs. - 0167-6997. ; 22:4, s. 411-20
  • Tidskriftsartikel (refereegranskat)abstract
    • The novel alkylating dipeptide melphalanyl-p-L-fluorophenylalanine ethyl ester (J1) was evaluated for acute toxicity and antitumor activity in mice, with melphalan as a reference. To determine a safe and tolerable dose for efficacy studies the acute toxicity following intravenous injection in the tail vein was monitored using a 14-day schedule with up to four doses. The highest tested dose, 25 micromoles/kg, was considered close to this level, with minor effects on body weight gain but significant effects on hematological parameters. Melphalan and J1 appeared equitoxic with no statistically significant differences. Subsequently a mouse hollow fiber model was employed with subcutaneous implantation of fibers containing human tumor cells. Three different human tumor cell lines as well as two samples of primary human tumor cells (ovarian carcinoma and chronic lymphatic leukemia) were used as tumor models. At the dose level tested there was a marked and statistically significant decrease in both T-cell leukemia CCRF-CEM and small cell lung cancer NCI-H69 tumor cell growth and viability in response to J1 as compared with both placebo and melphalan treated groups. In primary ovarian carcinoma cells only J1 treatment resulted in significant tumor regression (net cell kill). In summary the results indicate that, despite an expected short half time in the blood circulation, the promising in vitro data from the previous studies of J1 seems translatable into the in vivo situation. At equal doses of alkylating units J1, compared to melphalan, was more active in the mouse hollow-fiber model, but showed similar general toxicity.
  • Hassan, Saadia Bashir, 1959- (författare)
  • Methods for Preclinical Evaluation of Cytotoxic Drugs With Special Reference to the Cyanoguanidine CHS 828 and Hollow Fiber Method
  • 2004
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • <p>The novel cyanoguanidine CHS 828 has shown promising antitumor activity in many in vitro and in vivo studies. </p><p>The long-term 14 days in vitro hollow fiber cultures, where tumor cells from different tumor cell lines were cultured inside semipermeable fibers, were more resistant to CHS 828 and other cytotoxic drugs than the shorter-term 3 days cultures. CHS 828 was generally more effective against haematological than solid tumor cells from both cell lines and patients samples. </p><p>In vivo, the hollow fibers were implanted into immunocompetent rats and the pharmacokinetics, tumor response and/or toxicity (pharmacodynamics) of CHS 828 were successfully assayed. CHS 828 showed higher activity in this model when a more protracted schedule was used. The quantitative relationships between dose, plasma concentration and response (PK/PD model) developed for CHS 828 explained this phenomenon partly by dose-dependent fraction absorbed and partly by a schedule-dependent pharmacodynamic effect.</p><p>Modelling of the in vitro CHS 828 and standard cytotoxic drugs concentration-time effect data in different tumor cell types and characterization of pattern of change of the potency and the slope of the concentration-time effect curves were performed. The results suggest two different mechanisms of action for CHS 828 and that CHS 828 cytotoxicity may depend on the schedule used.</p><p>The NF-kB pathway that regulates the transcription of anti-apoptotic genes proved to be inhibited by CHS 828 in different tumor cell lines and the inhibition was correlated to the cell death induced by this agent. CHS 828 did not seem to induce the NF-kB inhibition by affecting the proteasome activity. </p><p>The in vitro and in vivo hollow fiber methods were also used successfully to evaluate the new paclitaxel formulation, Pacliex. Pacliex had a similar activity to that of the clinically used formulation Taxol®.</p>
  • Aftab, Obaid, 1984-, et al. (författare)
  • Label free quantification of time evolving morphologies using time-lapse video microscopy enables identity control of cell lines and discovery of chemically induced differential activity in iso-genic cell line pairs
  • 2015
  • Ingår i: Chemometrics and Intelligent Laboratory Systems. - 0169-7439 .- 1873-3239. ; 141, s. 24-32
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>Label free time-lapse video microscopy based monitoring of time evolving cell population morphology has potential to offer a simple and cost effective method for identity control of cell lines. Such morphology monitoring also has potential to offer discovery of chemically induced differential changes between pairs of cell lines of interest, for example where one in a pair of cell lines is normal/sensitive and the other malignant/resistant. A new simple algorithm, pixel histogram hierarchy comparison (PHHC), for comparison of time evolving morphologies (TEM) in phase contrast time-lapse microscopy movies was applied to a set of 10 different cell lines and three different iso-genic colon cancer cell line pairs, each pair being genetically identical except for a single mutation. PHHC quantifies differences in morphology by comparing pixel histogram intensities at six different resolutions. Unsupervised clustering and machine learning based classification methods were found to accurately identify cell lines, including their respective iso-genic variants, through time-evolving morphology. Using this experimental setting, drugs with differential activity in iso-genic cell line pairs were likewise identified. Thus, this is a cost effective and expedient alternative to conventional molecular profiling techniques and might be useful as part of the quality control in research incorporating cell line models, e.g. in any cell/tumor biology or toxicology project involving drug/agent differential activity in pairs of cell line models.</p>
  • Burman, Robert, 1979-, et al. (författare)
  • Evaluation of toxicity and anti-tumour activity of cycloviolacin O2 in mice.
  • 2010
  • Ingår i: Biopolymers. - 0006-3525 .- 1097-0282. ; 94:5, s. 626-634
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>Cycloviolacin O2 is a small cyclic cysteine-rich protein belonging to the group of plant proteins called cyclotides. This cyclotide has been previously shown to exert cytotoxic activity against a variety of human tumor cell lines as well as primary cultures of human tumor cells <em>in vitro</em>. This study is the first evaluation of its tolerability and antitumor activity <em>in vivo</em>. Maximal-tolerated doses were estimated to 1.5 mg/kg for single intravenous (i.v.) dosing and 0.5 mg/kg for daily repeated dosing, respectively. Two different in vivo methods were used: the hollow fiber method with single dosing (i.v. 1.0 mg/kg) and traditional xenografts with repeated dosing over 2 weeks (i.v. 0.5 mg/kg daily, 5 days a week). The human tumor cell lines used displayed dose-dependent in vitro sensitivity (including growth in hollow fibers to confirm passage of cycloviolacin O2 through the polyvinylidene fluoride fibers), with IC<sub>50</sub> values in the micromolar range. Despite this sensitivity in vitro, no significant antitumor effects were detected in vivo, neither with single dosing in the hollow fiber method nor with repeated dosing in xenografts. In summary, the results indicate that antitumor effects are minor or absent at tolerable (sublethal) doses, and cycloviolacin O2 has a very abrupt <em>in vivo</em> toxicity profile, with lethality after single injection at 2 mg/kg, but no signs of discomfort to the animals at 1.5 mg/kg. Repeated dosing of 1 mg/kg gave a local-inflammatory reaction at the site of injection after 2–3 days; lower doses were without complications.</p>
  • Eriksson, Mathilda, et al. (författare)
  • Utilization of a right-handed coiled-coil protein from archaebacterium Staphylothermus marinus as a carrier for cisplatin
  • 2009
  • Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 29:1, s. 11-18
  • Tidskriftsartikel (refereegranskat)abstract
    • <p><strong>BACKGROUND:</strong></p> <p>The nano-sized right-handed coiled-coil (RHCC) protein, originating from the archaebacterium Staphylothermus marinus, is stable at high salt concentrations, high temperatures, high pressures and extremes of pH. Its crystal structure reveals four hydrophobic cavities which can incorporate heavy metals. Nano-sized compounds have been used to carry cytotoxic drugs to tumours, avoiding delivery to healthy tissue, in part due to enhanced permeability in tumour blood vessels (enhanced permeability and retention effect).</p> <p><strong>MATERIALS AND METHODS:</strong></p> <p>The ability of RHCC to carry the platinum-containing chemotherapeutic drug cisplatin to cells, while retaining the cytotoxic potential was tested both in vitro and in vivo.</p> <p><strong>RESULTS:</strong></p> <p>RHCC was able to bind and enter cells in vitro and was not severely toxic or immunogenic in mice. Moreover, RHCC incorporated cisplatin, without inhibiting the cytotoxic potential of the drug against tumour cell lines in vitro or in vivo.</p> <p><strong>CONCLUSION:</strong></p> <p>RHCC can be used as a carrier of cisplatin without abrogating the effect of the drug.</p>
  • Friberg, Lena, et al. (författare)
  • Pharmacokinetic-Pharmacodynamic modelling of the schedule-dependent effect of the anti-cancer agent CHS 828 in a rat hollow fibre model
  • 2005
  • Ingår i: European Journal of Pharmaceutical Sciences. - 0928-0987 .- 1879-0720. ; 25:1, s. 163-173
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>N-(6-Chlorophenoxyhexyl)-N'-cyano-N''-4-pyridylguanidine (CHS 828) is a novel anticancer agent that shows schedule-dependent effects in vitro and in vivo, as well as in Phase I clinical trials. A rat hollow fibre model was used to investigate whether this dependency is due to pharmacokinetic and/or pharmacodynamic factors. The effect on two cell lines, MDA-MB-231 (breast cancer) and CCRF-CEM (leukaemia) were studied after CHS 828 was administered orally as a single dose or in a 5-day schedule, at different total dose levels. The 5-day schedules were associated with greater effects on both cell lines compared with single doses. A one-compartment pharmacokinetic model, with a half-life of 2.3h and a consecutive zero- and first-order process to describe dissolution and absorption, fit the concentration data. Pharmacokinetics were dose-dependent, as the fraction absorbed decreased with increasing dose. Clearance increased with accumulative exposure. Twenty hours after administration, concentrations started to increase again, probably due to coprophagy. Pharmacokinetic-pharmacodynamic models characterized the cell growth and cell kill over time and showed that schedule-dependent antitumour effects were present also when the dose-dependent pharmacokinetics were accounted for. The prolonged schedules of CHS 828 were therefore associated with greater antitumour effects than single doses of the same total exposure.</p>
  • Fryknäs, Mårten, et al. (författare)
  • Screening for phenotype selective activity in multidrug resistant cells identifies a novel tubulin active agent insensitive to common forms of cancer drug resistance
  • 2013
  • Ingår i: BMC Cancer. - 1471-2407 .- 1471-2407. ; 13, s. 374
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>Background: Drug resistance is a common cause of treatment failure in cancer patients and encompasses a multitude of different mechanisms. The aim of the present study was to identify drugs effective on multidrug resistant cells. Methods: The RPMI 8226 myeloma cell line and its multidrug resistant subline 8226/Dox40 was screened for cytotoxicity in response to 3,000 chemically diverse compounds using a fluorometric cytotoxicity assay (FMCA). Follow-up profiling was subsequently performed using various cellular and biochemical assays. Results: One compound, designated VLX40, demonstrated a higher activity against 8226/Dox40 cells compared to its parental counterpart. VLX40 induced delayed cell death with apoptotic features. Mechanistic exploration was performed using gene expression analysis of drug exposed tumor cells to generate a drug-specific signature. Strong connections to tubulin inhibitors and microtubule cytoskeleton were retrieved. The mechanistic hypothesis of VLX40 acting as a tubulin inhibitor was confirmed by direct measurements of interaction with tubulin polymerization using a biochemical assay and supported by demonstration of G2/M cell cycle arrest. When tested against a broad panel of primary cultures of patient tumor cells (PCPTC) representing different forms of leukemia and solid tumors, VLX40 displayed high activity against both myeloid and lymphoid leukemias in contrast to the reference compound vincristine to which myeloid blast cells are often insensitive. Significant in vivo activity was confirmed in myeloid U-937 cells implanted subcutaneously in mice using the hollow fiber model. Conclusions: The results indicate that VLX40 may be a useful prototype for development of novel tubulin active agents that are insensitive to common mechanisms of cancer drug resistance.</p>
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