• P-glycoprotein (MDR1) expression in leukemic cells is regulated at two distinct steps, mRNA stabilization and translational initiation.

      Yague, Ernesto; Armesilla, Angel Luis; Harrison, Georgina; Elliott, James; Sardini, Alessandro; Higgins, Christopher F.; Raguz, Selina (American Society for Biochemistry and Molecular Biology, 2003)
      Multidrug resistance in acute myeloid leukemia is often conferred by overexpression of P-glycoprotein, encoded by the MDR1 gene. We have characterized the key regulatory steps in the development of multidrug resistance in K562 myelogenous leukemic cells. Unexpectedly, up-regulation of MDR1 levels was not due to transcriptional activation but was achieved at two distinct post-transcriptional steps, mRNA turnover and translational regulation. The short-lived (half-life 1 h) MDR1 mRNA of naive cells (not exposed to drugs) was stabilized (half-life greater than 10 h) following short-term drug exposure. However, this stabilized mRNA was not associated with translating polyribosomes and did not direct P-glycoprotein synthesis. Selection for drug resistance, by long-term exposure to drug, led to resistant lines in which the translational block was overcome such that the stabilized mRNA was translated and P-glycoprotein expressed. The absence of a correlation between steady-state MDR1 mRNA and P-glycoprotein levels was not restricted to K562 cells but was found in other lymphoid cell lines. These findings have implications for the avoidance or reversal of multidrug resistance in the clinic.
    • Peptide Synthesis and Applications

      Howl, John D. (Clifton, N.J.: Humana Press, 2005)
      Hands-on experts describe in step-by-step detail the key methodologies of contemporary peptide synthesis and illustrate their numerous applications. The techniques presented include protocols for chemical ligation, the synthesis of cyclic and phosphotyrosine-containing peptides, lipoamino acid- and sugar-conjugated peptides, and peptide purification and analyses. Additional chapters detail methodologies and instrumentation for high-throughput peptide synthesis, many different applications of peptides as novel research tools and biological probes, and the design and application of fluorescent substrate-based peptides that can be used to determine the selectivity and activity of peptidases. A practical guide to the identification of proteins using mass spectrometric analyses of peptide mixtures is also included. (Humana Press)
    • Peptidyl-based delivery systems as a strategy for the therapeutic intervention of human astrocytoma and medulloblastoma

      Jones, Sarah; Howl, John D. (Springer Verlag, 2006)
      THIS BOOK: Understanding Biology Using Peptides: Proceedings of the 19th American Peptide Symposium highlights many of the recent developments in peptide science, with a particular emphasis on how these advances are being applied to basic problems in biology and medicine. Specific topics covered include novel synthetic strategies, peptides in biological signaling, post-translational modifications of peptides and proteins, peptide quaternary structure in material science and disease, and peptides as tools in drug discovery. (Springer Verlag)
    • Pharmacogenomic dissection of resistance to thymidylate synthase inhibitors.

      Wang, Weiguang; Marsh, S.; Cassidy, James; McLeod, Howard (American Association for Cancer Research, 2001)
      Chemoresistance is a major obstacle for successful cancer treatment. Gene amplification and altered expression are the main genetic mechanisms of tumor chemoresistance. Previously, only a limited number of genes were analyzed in each individual study using traditional molecular methods such as Northern and Southern blotting. In this study, the global gene expression patterns of 1176 genes in a panel of five thymidylate synthase (TS) inhibitor [raltitrexed (TDX) and 5-fluorouracil (5-FU)] resistant and sensitive parent cell lines were investigated using cDNA array technology. Only 28 of 1176 genes were altered >1.5-fold among resistant cells, with 2 genes (TS and YES1) consistently higher in the panel. TS mRNA and protein were consistently overexpressed in all drug-resistant tumor cell lines compared with the sensitive parent cell lines. Southern blot and FISH analysis demonstrated that the TS gene was amplified in 5-FU- and TDX-resistant cell lines. YES1 mRNA and protein were overexpressed in four drug-resistant tumor cell lines but were not overexpressed in the lymphoblast cell line W1L2(TDX), although the YES1 gene was highly amplified in these cells. The fact that W1L2 has high level (>10-fold) resistance to TS inhibitor in the absence of high YES1 expression leads to a conclusion that YES1 has no direct role in this drug resistance process. By narrowing the search from 1176 to 2 genes, the analysis of in vitro TDX and 5-FU resistance becomes more straightforward for confirmatory studies. These data provide encouragement that comprehensive transcript analysis will aid the quest for more enlightened therapeutics.
    • Phytoestrogens: perpetrators or protectors?

      Martin, Jan H.; Crotty, Stephen; Nelson, Paul N. (Future Medicine Ltd, 2007)
      Phytoestrogens are estrogen-like substances produced by plants that account for some of the constituents present in vegetation that may be responsible for the health benefits of a diet rich in fruit and vegetables. Phytoestrogens have a plethora of different actions that they are capable of exerting on cellular metabolism. This review will focus on some of the major non-estrogen receptor-mediated cellular effects used by phytoestrogens and will draw attention to the fact that while they may have a number of beneficial effects, particularly in offering a protective effect against some hormone-dependent cancers, such as breast and prostate cancer, they may also have possible unfavorable effects by interfering with the functioning of normal cellular activities such as receptor-mediated signal transduction and DNA replication, as well as being genotoxic, mutagenic and promoting the proliferation of some cancer cells.
    • Picornavirus uncoating.

      Smyth, M.S.; Martin, Jan H. (British Medical Association, 2002)
      Recently, much has been learned about the molecular mechanisms involved in the pathogenesis of picornaviruses. This has been accelerated by the solving of the crystal structures of many members of this virus family. However, one stage of the virus life cycle remains poorly understood: uncoating. How do these simple but efficient pathogens protect their RNA genomes with a stable protein shell and yet manage to uncoat this genome at precisely the right time during infection? The purpose of this article is to review the current state of knowledge and the most recent theories that attempt to answer this question. The review is based extensively on structural data but also makes reference to the wealth of biochemical information on the topic.
    • Plasma membrane Ca2+ ATPase 4 is required for sperm motility and male fertility.

      Schuh, Kai; Cartwright, Elizabeth J.; Jankevics, Eriks; Bundschu, Karin; Liebermann, Jürgen; Williams, Judith C.; Armesilla, Angel Luis; Emerson, Michael; Oceandy, Delvac; Knobeloch, Klaus-Peter; et al. (American Society for Biochemistry and Molecular Biology, 2004)
      Calcium and Ca(2+)-dependent signals play a crucial role in sperm motility and mammalian fertilization, but the molecules and mechanisms underlying these Ca(2+)-dependent pathways are incompletely understood. Here we show that homozygous male mice with a targeted gene deletion of isoform 4 of the plasma membrane calcium/calmodulin-dependent calcium ATPase (PMCA), which is highly enriched in the sperm tail, are infertile due to severely impaired sperm motility. Furthermore, the PMCA inhibitor 5-(and-6)-carboxyeosin diacetate succinimidyl ester reduced sperm motility in wild-type animals, thus mimicking the effects of PMCA4 deficiency on sperm motility and supporting the hypothesis of a pivotal role of the PMCA4 on the regulation of sperm function and intracellular Ca(2+) levels.
    • Preoperative mitomycin, ifosfamide, and cisplatin followed by esophagectomy in squamous cell carcinoma of the esophagus: pathologic complete response induced by chemotherapy leads to long-term survival.

      Darnton, S.J.; Archer, V.R.; Stocken, D.D.; Mulholland, P.J.; Casson, A.G.; Ferry, David R. (American Society of Clinical Oncology, 2003)
      PURPOSE: Squamous cell carcinoma of the esophagus remains an aggressive disease with a poor prognosis, even after curative-intent surgery. This article analyzes the impact of preoperative chemotherapy with mitomycin, ifosfamide, and cisplatin (MIC) on a cohort of 68 patients. PATIENTS AND METHODS: From 1988 to 1994, 68 patients with potentially operable squamous cell carcinoma of the esophagus were entered onto two phase II trials of neoadjuvant chemotherapy with mitomycin 6 mg/m2, ifosfamide 3 g/m2, and cisplatin 50 mg/m2 and received between two and four cycles of treatment at 3-weekly intervals. Two patients were removed from the analysis when they were found to have malignancy other than squamous cell carcinoma of the esophagus. RESULTS: Forty (61%) of 66 patients had a radiologic response to chemotherapy (18 complete responses and 22 partial responses), and 52 (79%) of 66 patients went on to have the primary tumor resected. There were nine pathologic complete responders, seven of whom remain fit and well after at least 60 months of follow-up. The overall median survival was 12.4 months (95% confidence interval, 9.6 to 18.8 months). The complete response and node-negative patients survived significantly longer than those in other categories (log-rank chi2 = 18.8; P <.001): on average 13 months longer than the node-positive or nonresected category (22.0 v 9.4 months). The toxicity of the regimen was low. CONCLUSION: MIC is an easily administered, well-tolerated, and efficacious regimen as neoadjuvant therapy for patients with squamous cell carcinoma of the esophagus. These results warrant further investigation.
    • Pressurized liquid extraction of active ingredients (ginsenosides) from medicinal plants using non-ionic surfactant solutions.

      Choi, Maggie P.K.; Chan, Kelvin C.; Leung, Hei Wun; Huie, Carmen W. (Elsevier, 2003)
      The feasibility of employing aqueous non-ionic surfactant solutions as an alternative solvent system in pressurized liquid extraction (PLE) is demonstrated for the first time using the roots of American ginseng as model solid samples. When compared to the use of pure water or methanol, the presence of a common non-ionic surfactant (Triton X-100) in water at a concentration above its critical micelle concentration was shown to enhance the amount of pharmacologically active ingredients (ginsenosides) extracted from ginseng roots. The advantages of using aqueous non-surfactant solutions were also demonstrated by comparing extraction performances between ultrasonic-assisted extraction and PLE methods. Furthermore, the combination of PLE and cloud point extraction was shown to be a new and effective approach for the rapid sample preconcentration of herbal materials prior to analysis by high-performance liquid chromatography.
    • Pseudoislets as primary islet replacements for research: Report on a symposium at King's College London, London UK

      Persaud, Shanta; Arden, Catherine; Bergsten, P.; Bone, Adrian J.; Brown, James; Dunmore, Simon J; Harrison, Moira; Hauge-Evans, Astrid; Kelly, Catriona; King, Aileen; et al. (Landes Bioscience, 2010)
      Laboratory-based research aimed at understanding processes regulating insulin secretion and mechanisms underlying β-cell dysfunction and loss in diabetes often makes use of rodents, as these processes are in many respects similar between rats/mice and humans. Indeed, a rough calculation suggests that islets have been isolated from as many as 150,000 rodents to generate the data contained within papers published in 2009 and the first four months of 2010. Rodent use for islet isolation has been mitigated, to a certain extent, by the availability of a variety of insulin-secreting cell lines that are used by researchers world-wide. However, when maintained as monolayers the cell lines do not replicate the robust, sustained secretory responses of primary islets which limits their usefulness as islet surrogates. On the other hand, there have been several reports that configuration of MIN6 β-cells, derived from a mouse insulinoma, as three-dimensional cell clusters termed ‘pseudoislets’ largely recapitulates the function of primary islet β-cells. The Diabetes Research Group at King’s College London has been using the MIN6 pseudoislet model for over a decade and they hosted a symposium on “Pseudoislets as primary islet replacements for research”, which was funded by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), in London on 15th and 16th April 2010. This small, focused meeting was conceived as an opportunity to consolidate information on experiences of working with pseudoislets between different UK labs, and to introduce the theory and practice of pseudoislet culture to laboratories working with islets and/or β-cell lines but who do not currently use pseudoislets. This short review summarizes the background to the development of the cell line-derived pseudoislet model, the key messages arising from the symposium and emerging themes for future pseudoislet research
    • Quality control of herbal medicines

      Liang, Yi-Zeng; Xie, Peishan; Chan, Kelvin C. (Elsevier, 2004)
      Different chromatographic and electrophoretic techniques commonly used in the instrumental inspection of herbal medicines (HM) are first comprehensively reviewed. Chemical fingerprints obtained by chromatographic and electrophoretic techniques, especially by hyphenated chromatographies, are strongly recommended for the purpose of quality control of herbal medicines, since they might represent appropriately the "chemical integrities" of the herbal medicines and therefore be used for authentication and identification of the herbal products. Based on the conception of phytoequivalence, the chromatographic fingerprints of herbal medicines could be utilized for addressing the problem of quality control of herbal medicines. Several novel chemometric methods for evaluating the fingerprints of herbal products, such as the method based on information theory, similarity estimation, chemical pattern recognition, spectral correlative chromatogram (SCC), multivariate resolution, etc. are discussed in detail with examples, which showed that the combination of chromatographic fingerprints of herbal medicines and the chemometric evaluation might be a powerful tool for quality control of herbal products.
    • Randomised controlled trial of a home-based physical activity intervention in breast cancer survivors

      Lahart, Ian M.; Metsios, George S.; Nevill, Alan M.; Kitas, George D.; Carmichael, Amtul R. (2016-03-17)
      Background: To improve adherence to physical activity (PA), behavioural support in the form of behavioural change counselling may be necessary. However, limited evidence of the effectiveness of home-based PA combined with counselling in breast cancer patients exists. The aim of this current randomised controlled trial with a parallel group design was to evaluate the effectiveness of a home-based PA intervention on PA levels, anthropometric measures, health-related quality of life (HRQoL), and blood biomarkers in breast cancer survivors. Methods: Eighty post-adjuvant therapy invasive breast cancer patients (age = 53.6 ± 9.4 years; height = 161.2 ± 6.8 cm; mass = 68.7 ± 10.5 kg) were randomly allocated to a 6-month home-based PA intervention or usual care. The intervention group received face-to-face and telephone PA counselling aimed at encouraging the achievement of current recommended PA guidelines. All patients were evaluated for our primary outcome, PA (International PA Questionnaire) and secondary outcomes, mass, BMI, body fat %, HRQoL (Functional assessment of Cancer Therapy-Breast), insulin resistance, triglycerides (TG) and total (TC), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterol were assessed at baseline and at 6-months. Results: On the basis of linear mixed-model analyses adjusted for baseline values performed on 40 patients in each group, total, leisure and vigorous PA significantly increased from baseline to post-intervention in the intervention compared to usual care (between-group differences, 578.5 MET-min∙wk−1, p = .024, 382.2 MET-min∙wk−1, p = .010, and 264.1 MET-min∙wk−1, p = .007, respectively). Both body mass and BMI decreased significantly in the intervention compared to usual care (between-group differences, −1.6 kg, p = .040, and −.6 kg/m2, p = .020, respectively). Of the HRQoL variables, FACT-Breast, Trial Outcome Index, functional wellbeing, and breast cancer subscale improved significantly in the PA group compared to the usual care group (between-group differences, 5.1, p= .024; 5.6, p = .001; 1.9 p = .025; and 2.8, p=.007, respectively). Finally, TC and LDL-C was significantly reduced in the PA group compared to the usual care group (between-group differences, −.38 mmol∙L−1, p=.001; and −.3 mmol∙L−1, p=.023, respectively). Conclusions: We found that home-based PA resulted in significant albeit small to moderate improvements in selfreported PA, mass, BMI, breast cancer specific HRQoL, and TC and LDL-C compared with usual care.
    • Reactivity and isotype profiling of monoclonal antibodies using multiple antigenic peptides.

      Waldron, E.E.; Murray, Paul G.; Kolar, Zdenek; Young, Lawrence S.; Brown, C.; Reynolds, Gary; Baumforth, Karl R. N.; Toomey, S.; Astley, S.J.; Perera, Shantha; et al. (New Rochelle (NY): Mary Ann Liebert, Inc., 2002)
      The characterisation of monoclonal antibodies (MAbs) is essential for the development of assay systems particularly where antigens have been developed using synthetic peptides. Indeed some peptide-carrier conjugates fail to induce immune responses and may not generate antibodies that bind to native protein. As an alternative to peptide-carrier conjugates, multiple antigenic peptides (MAPs) have been used for immunization strategies, but with little regard to the characteristics of the MAbs produced. In this study, we used 3 MAPs of Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) to immunise BALB/c mice. Overall, the polyclonal antibody responses from tail bleeds showed that MAPs evoked B-cell responses. However, on screening 144 hybridomas, 24 MAb supernatants exhibited weak to moderate reactivity in enzyme-linked immunosorbant assay (ELISA) and against cell cytospin preparations (B95.8 and AG876 LCL), respectively. Isotype profiling of hybridoma supernatants also showed that 11 out of 24 were IgM. Further characterization of 6 MAbs in Western blotting showed reactivity to recombinant LMP1 and only one MAb (B28D) showed weak reactivity to the malignant cells (Hodgkin/Reed-Sternberg; HRS cells) of an EBV+ Hodgkin's lymphoma using paraffin-embedded tissue. It is probable that these MAPs failed to augment T-cell help and contributed to the production of low affinity (IgM) antibodies. These observations may be of importance to future immunization strategies, where MAPs are used in the production of monoclonal reagents.
    • Recent advances in the engineering of nanosized active pharmaceutical ingredients: Promises and challenges

      Kaialy, Waseem; Al Shafiee, Maen (Elsevier BV, 2015-12-08)
      The advances in the field of nanotechnology have revolutionized the field of delivery of poorly soluble active pharmaceutical ingredients (APIs). Nanosized formulations have been extensively investigated to achieve a rapid dissolution and therefore pharmacokinetic properties similar to those observed in solutions. The present review outlines the recent advances, promises and challenges of the engineering nanosized APIs. The principles, merits, demerits and applications of the current ‘bottom-up’ and ‘top-down’ technologies by which the state of the art nanosized APIs can be produced were described. Although the number of research reports on the nanoparticle engineering topic has been growing in the last decade, the challenge is to take numerous research outcomes and convert them into strategies for the development of marketable products.
    • Reduced expression of endothelial and inducible nitric oxide synthase in a multidrug resistant variant of the MCF-7 human breast cancer cell line.

      Lahiri, M.; Martin, Jan H. (Spandidos Publications Ltd, 2004)
      The purpose of the present study was to investigate expression of endothelial and inducible nitric oxide synthase in the MCF-7 human breast cancer cell line compared to a multidrug resistant variant, MCF-7-ADR. Immunohistochemical investigations demonstrated 51% of MCF-7 cells stained positive for endothelial nitric oxide synthase, with 46% positive for inducible nitric oxide synthase. However, in the breast cancer cell line that was multidrug resistant there was a much lower positive staining for endothelial nitric oxide synthase at 20% and for inducible nitric oxide synthase at 15%. For the multidrug resistant variant, there was also lower nitric oxide production and the band intensity for immunoblotting for endothelial nitric oxide synthase was weaker than for the parent cell line. These results lend further support to the proposal that expression of NOS is negatively associated with human breast cancer progression.
    • Regulation of beta-cell viability and gene expression by distinct agonist fragments of adiponectin

      Brown, James E. P.; Conner, Alex C..; Digby, Janet E.; Ward, Kenya L.; Ramanjaneya, Manjunath; Randeva, Harpal S.; Dunmore, Simon J. (2010)
      Obesity is an established risk factor for type 2 diabetes. Activation of the adiponectin receptors has a clear role in improving insulin resistance although conflicting evidence exists for its effects on pancreatic beta-cells. Previous reports have identified both adiponectin receptors (ADR-1 and ADR-2) in the betacell. Recent evidence has suggested that two distinct regions of the adiponectin molecule, the globular domain and a small N-terminal region, have agonist properties. This study investigates the effects of two agonist regions of adiponectin on insulin secretion, gene expression, cell viability and cell signalling in the rat beta-cell line BRIN-BD11, as well as investigating the expression levels of adiponectin receptors (ADRs) in these cells. Cells were treated with globular adiponectin and adiponectin (15-36)±leptin to investigate cell viability, expression of key beta-cell genes and ERK1/2 activation. Both globular adiponectin and adiponectin (15-36) caused significant ERK1/2 dependent increases in cell viability. Leptin co-incubation attenuated adiponectin (15-36) but not globular adiponectin induced cell viability. Globular adiponectin, but not adiponectin (15-36), caused a significant 450% increase in PDX-1 expression and a 45% decrease in LPL expression. ADR-1 was expressed at a higher level than ADR-2, and ADR mRNA levels were differentially regulated by non-esterified fatty acids and peroxisome-proliferator-activated receptor agonists. These data provide evidence of roles for two distinct adiponectin agonist domains in the beta-cell and confirm the potentially important role of adiponectin receptor agonism in maintaining beta-cell mass.
    • Regulation of uncoupling protein-2 (UCP-2) expression in human glioma cells by peroxisome proliferators-activated receptor (PPAR) agonists

      Brown, James E. P.; Darling, John L.; Dunmore, Simon J.; Bassey, S. (Society for Neuro-Oncology and Duke University Press, 2005)
      Recent studies have suggested that the glitazones, a group of PPAR agonists commonly prescribed as therapy in type 2 diabetes, could have a role in regulation of cell viability in astrocytomas and glioma cell lines, possibly due to a modulation of reactive oxygen species (ROS) production. PPAR agonists are also known to regulate expression of the mitochondrial protein UCP-2, and UCP-2 has a purported role in ROS regulation amongst others. This study investigated the expression of UCP-2 in U251MG glioma cells and its regulation by PPAR agonists. U251MG glioma cells were cultured according to standard methods and treated with PPAR alpha, delta, and gamma agonists (10 μM WY14643, 10 nM PGI2, 10 μM rosiglitazone and 10 nM PGJ2, respectively) for 24 h. Total RNA was subsequently extracted and semiquantitative RT-PCR used to evaluate UCP-2 mRNA expression. Results showed that UCP-2 was expressed in all control and treatment samples and that its expression was regulated differentially by the various PPAR receptor subtype agonists tested. This novel finding that UCP-2 is expressed in glioma cells, and that its expression is regulated by PPAR agonists, suggests a potential mechanism for the cytotoxic effects of glitazones that have been previously reported, and describes a mechanism which could possibly be manipulated as a potential therapeutic avenue in the future.
    • Resistance of medical biofilms

      Brown, Michael R. W.; Smith, Anthony W. (IWA Publishing, 2003)
      This timely book will introduce its readers to the structure and function of biofilms at a fundamental level as determined during the past decade of research, including: Extracellular polymers as the biofilm matrix; Biofilm phenotype (differential gene expression, interspecies signalling); Biofilm ecology; Biofilm monitoring; Resistance of biofilms to antimicrobial agents and Biofilm abatement. (IWA Publishing)
    • Resistin down-regulates insulin receptor expression, and modulates cell viability in rodent pancreatic beta-cells.

      Brown, James E. P.; Onyango, David J.; Dunmore, Simon J. (Elsevier, 2007)
      The adipokine resistin is known to induce insulin resistance in rodent tissues. Increases in adipose tissue mass are known to have a negative effect on pancreatic beta-cell function, although the mechanisms are poorly understood. This study investigated the effects of resistin on insulin secretion, insulin receptor expression and cell viability in pancreatic beta-cells. BTC-6 or BRIN-BD11 cells were treated for 24h with resistin, and insulin receptor expression, insulin secretion and cell viability were measured. Incubation with 40ng/ml resistin caused significant decreases in insulin receptor mRNA and protein expression, but did not affect insulin secretion. At low concentrations, resistin caused significant increases in cell viability. These data implicate resistin as a factor that may regulate beta-cell function/viability, and suggests a potential mechanism by which increased adiposity causes beta-cell dysfunction.
    • Response of short-term cultures derived from human malignant glioma to aziridinylbenzoquinone, etoposide and doxorubicin: an in vitro phase II trial.

      Darling, John L.; Thomas, David G. (Lippincott Williams & Wilkins, Inc., 2001)
      The relative resistance of malignant glioma to chemotherapy makes the identification of new cytotoxic drugs critically important. The use of short-term cultures derived from these tumors to screen drugs at doses that can be attained within human intracranial tumors provides a model system that should be capable of identifying effective drugs suitable for clinical evaluation. The sensitivity of a panel of short-term cultures derived from 22 malignant astrocytoma and four malignant oligodendroglioma was assessed to aziridinylbenzoquinone (AZQ), etoposide and doxorubicin (DOX) using a [(35)S] methione uptake assay. The ID(50) of each culture was compared to the levels of drug which could be achieved in the tumor using standard doses. There was marked heterogeneity between cultures in response to each drug. Whilst there was no evidence that cultures derived from grade III astrocytoma were more sensitive to any of the drugs than cultures derived from grade IV astrocytoma, cultures derived from oligodendroglioma tended to be more sensitive to the alkylating agent AZQ, but not to either of the other drugs. The sensitivity of these short-term cultures at concentrations that can be achieved in situ corresponded well with the clinical efficacy of AZQ and etoposide. Although DOX appeared to be toxic to human gliomas cells in vitro, its limited penetration into the intact brain would seem to preclude its use i.v., but it is likely to be effective if local drug delivery techniques could be employed. The study suggests that short-term cultures derived from malignant glioma should be used to screen investigational agents for potential clinical efficacy.