• Low O6-alkylguanine DNA-alkyltransferase activity in normal colorectal tissue is associated with colorectal tumours containing a GC-->AT transition in the K-ras oncogene.

      Jackson, Peta E; Hall, C N; O'Connor, Peter J; Cooper, Donald P; Margison, Geoffrey P; Povey, Andrew C; Cancer Research Campaign Department of Carcinogenesis, Paterson Institute for Cancer Research, Manchester, UK. (1997-07)
      O6-alkylguanine DNA-alkyltransferase (ATase) provides protection against the toxic, mutagenic and carcinogenic effects of alkylating agents, principally by removing the promutagenic lesion O6-alkylguanine from DNA. Differences in ATase activity in human tissue may thus determine mutational susceptibility. As GC-->AT transitions, which can be induced by O6-alkylguanine in DNA, are commonly observed in the K-ras oncogene of alkylating agent induced animal tumours and in human colorectal tumours, we have examined whether differences in ATase activity may affect the risk of K-ras mutations in humans with colorectal tumours. NTase activity in normal tissue from individuals with a K-ras mutation in colorectal tissue and more specifically a GC-->AT transition (but not a transversion mutation) was significantly lower than that in individuals without a mutation (P < 0.01). Thus, individuals with low ATase activity in normal tissue (i.e. below the median) were at increased risk of having a transition (OR 10.1; 95% CI 1.9-99.0), but not a transversion mutation (OR 1.7; 95% CI 0.3-12.2). There were no significant differences in tumour ATase activity in individuals with or without a mutation. These results suggest that ATase can protect colorectal tissue against the mutagenic effects of alkylating agents and furthermore, that alkylating agent exposure plays a role in the aetiology of colorectal tumours containing a GC-->AT transition in the K-ras oncogene.
    • Low perfusion compartments in glioblastoma quantified by advanced magnetic resonance imaging and correlated with patient survival

      Li, C; Yan, JL; Torheim, Turid; McLean, MA; Boonzaier, NR; Zou, J; Huang, Y; Yuan, J; van Dijken, BRJ; Matys, T; et al. (2019)
      BACKGROUND AND PURPOSE: Glioblastoma exhibits profound intratumoral heterogeneity in perfusion. Particularly, low perfusion may induce treatment resistance. Thus, imaging approaches that define low perfusion compartments are crucial for clinical management. MATERIALS AND METHODS: A total of 112 newly diagnosed glioblastoma patients were prospectively recruited for maximal safe resection. The apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) were calculated from diffusion and perfusion imaging, respectively. Based on the overlapping regions of lowest rCBV quartile (rCBVL) with the lowest ADC quartile (ADCL) and highest ADC quartile (ADCH) in each tumor, two low perfusion compartments (ADCH-rCBVL and ADCL-rCBVL) were identified for volumetric analysis. Lactate and macromolecule/lipid levels were determined from multivoxel MR spectroscopic imaging. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier's and multivariate Cox regression analyses, to evaluate the effects of compartment volume and lactate level on survival. RESULTS: Two compartments displayed higher lactate and macromolecule/lipid levels compared to contralateral normal-appearing white matter (each P?<?0.001). The proportion of the ADCL-rCBVL compartment in the contrast-enhancing tumor was associated with a larger infiltration on FLAIR (P?<?0.001, rho?=?0.42). The minimally invasive phenotype displayed a lower proportion of the ADCL-rCBVL compartment than the localized (P?=?0.031) and diffuse phenotypes (not significant). Multivariate Cox regression showed higher lactate level in the ADCL-rCBVL compartment was associated with worsened survival (PFS: HR 2.995, P?=?0.047; OS: HR 4.974, P?=?0.005). CONCLUSIONS: Our results suggest that the ADCL-rCBVL compartment may potentially indicate a clinically measurable resistant compartment.
    • Low-density lipoprotein uptake and the sensitivity to photodynamic treatment of cultured endothelial cells.

      West, Catharine M L; West, David C; Moore, James V; Cancer Research Campaign Department of Radiobiology, Paterson Institute for Cancer Research, Manchester, UK. (1991)
    • Low-level direct electrical current therapy for hepatic metastases. I. Preclinical studies on normal liver.

      Griffin, D T; Dodd, Nicholas J F; Zhao, S; Pullan, B R; Moore, James V; Paterson Institute for Cancer Research, Christie Hospital (NHS) Trust, Manchester, UK. (1995-07)
      Low-level direct electrical current has shown promise as a potential therapeutic modality (direct current therapy; DCT) in the treatment of malignant disease, including metastases, but to date much experimental work has been empirical and has added little to our knowledge of the mechanisms involved. As a prerequisite to a clinical trial for metastases in the liver, we have employed an in vivo liver model to examine the quantitative and qualitative relationships between electrode polarity, charge and tissue necrosis. Two distinct regions of necrosis were induced, distinguishable histologically and by magnetic resonance imaging: (i) a cylindrical region of primary necrosis centred on the electrode, its volume directly proportional to the charge passed, but greater at the anode than cathode; and (ii) a wedge-shaped infarct, apex at the electrode and base extending to the liver edge. The extent of this infarct was again greater at the anode than the cathode, but showed a sigmoidal relationship with charge. Results indicate pH changes at the electrodes as likely mediators of tissue injury, but show also that significant distant ischaemic injury can occur as a consequence of primary damage. These findings should be considered when selecting tumours for possible direct current therapy and when determining the sites of electrode placement.
    • A low-temperature method for the isolation of small-intestinal epithelium along the crypt-villus axis.

      Flint, Neil; Cove, Frances L; Evans, Gareth S; Department of Epithelial Biology, Paterson Institute for Cancer Research, Christie Hospital, Withington, Manchester, U.K. (1991-12-01)
      A variety of enzymic and non-enzymic methods to isolate epithelium from the small intestine have been previously published. Sequential fractionation of cells from the villus to the crypt has been reported in some of these papers, which allows the comparative study of terminally differentiated and proliferative cell phenotypes. However, these methods often involve the incubation of tissues at 37 degrees C, which may affect the structural and biochemical integrity of the cells. We have developed a rapid low-temperature (4 degrees C) method for isolating purified populations of crypt and villus cells from mouse and rat intestines. The fractionated cells have been partially characterized, and the potential value of the procedure has been indicated by the ability to analyse the comparative protein and mRNA expression along the crypt-villus axis.
    • The lower radiosensitivity of mouse kidney cells irradiated in vivo than in vitro: a cell contact effect phenomenon.

      Jen, Yee-Min; West, Catharine M L; Hendry, Jolyon H; Department of Radiobiology, Paterson Institute for Cancer Research, Christie Hospital and Holt Radium Institute, Manchester, U.K. (1991-06)
      For mouse kidney cells assayed in primary culture, the Do and n values were 1.1 +/- 0.06 Gy and 7 +/- 2 for single cells irradiated in vitro, and 1.3 +/- 0.08 Gy and 25 +/- 11 for in vivo irradiation. The lower radiosensitivity in vivo was shown not to be caused by natural hypoxia, as the average oxygen enhancement ratios were 2.6 +/- 0.3 for in vitro and 2.8 +/- 0.4 for in vivo irradiation. Irradiations of fragments of kidney tubules produced similar survivals as irradiations of kidneys in situ, even for irradiation immediately before the fragments were disaggregated into single cells. The critical point of change in radiosensitivity from in vivo to in vitro values due to this contact effect was the time that the kidney cells were monodispersed.
    • Lowest triplet properties of poly(2-vinylnaphthalene) in solution.

      Bensasson, R V; Ronfard-Haret, J; Land, Edward J; Webber, S (1979)
    • LSD1 inhibition: a therapeutic strategy in cancer?

      Lynch, James T; Harris, William J; Somervaille, Tim C P; The University of Manchester, Paterson Institute for Cancer Research, Cancer Research UK Leukaemia Biology Laboratory , Manchester, M20 4BX , UK. (2012-12)
      Introduction: The role of epigenetic dysfunction in cancer is increasingly appreciated. This has raised the question as to whether enzymes that regulate the structure and function of chromatin might represent novel therapeutic targets. The histone demethylase LSD1 is one such candidate and novel, potent inhibitors are under development. Areas covered: The literature on LSD1 (also known as KDM1A, AOF2, BHC110 or KIAA0601) was identified in Pubmed and is herein discussed. Areas covered include the structure and enzymatic activity of LSD1, its role in chromatin regulatory complexes, its functional roles in normal and malignant tissue, pharmacological inhibitors of its activity and their putative therapeutic roles. Expert opinion: Pre-clinical data supporting a therapeutic role for LSD1 inhibitors are most encouraging in acute myeloid leukaemia, although optimal dosing strategies and beneficial combinations with other agents remain unclear. Studies making use of potent, selective LSD1 inhibitors active in the nanomolar range are required to establish therapeutic indications in other subtypes of haematological malignancy, and in solid tumours.
    • LSD1 inhibitors disrupt the GFI1 transcription repressor complex.

      Maiques-Diaz, Alba; Lynch, James T; Spencer, Gary J; Somervaille, Tim C P; Leukaemia Biology Laboratory, Cancer Research UK Manchester Institute, The University of Manchester, Manchester (2018)
      Pharmacologic inhibition of KDM1A (Lysine Demethylase 1A) induces differentiation in certain subtypes of acute myeloid leukemia. Our recent studies reveal this is dependent upon drug-induced disruption of the GFI1 (Growth Factor Independent 1) transcription repressor complex, leading to activation of enhancers distributed close to genes controlling monocytic lineage differentiation.
    • LSD1: biologic roles and therapeutic targeting.

      Maiques-Diaz, Alba; Somervaille, Tim C P; Leukaemia Biology Laboratory, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX (2016-08)
      LSD1 (KDM1A; BHC110; AOF2) was the first protein reported to exhibit histone demethylase activity and has since been shown to have multiple essential roles in mammalian biology. Given its enzymatic activity and its high-level expression in many human malignancies, a significant recent focus has been the development of pharmacologic inhibitors. Here we summarize structural and biochemical knowledge of this important epigenetic regulator, with a particular emphasis on the functional and preclinical studies in oncology that have provided justification for the evaluation of tranylcypromine derivative LSD1 inhibitors in early phase clinical trials.
    • Luminescence excitation and de-excitation involving one-electron transfer.

      Prutz, Walter A; Land, Edward J; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (1978)
    • Luminescence from protoporphyrin IX dimethyl ester

      Chantrell, S; McAuliffe, C; Munn, R; Pratt, A; Land, Edward J (1975)
    • Lung cancer risk and variation in MGMT activity and sequence.

      Povey, Andrew C; Margison, Geoffrey P; Santibanez-Koref, Mauro F; Centre for Occupational and Environmental Health, University of Manchester, United Kingdom. a.povey@manchester.ac.uk (2007-08-01)
      O(6)-Alkylguanine-DNA alkyltransferase (MGMT) repairs DNA adducts that result from alkylation at the O(6) position of guanine. These lesions are mutagenic and toxic and can be produced by a variety of agents including the tobacco-specific nitrosamines, carcinogens present in cigarette smoke. Here, we review some of our work in the context of inter-individual differences in MGMT expression and their potential influence on lung cancer risk. In humans there are marked inter-individual differences in not only levels of DNA damage in the lung (N7-methylguanine) that can arise from exposure to methylating agents but also in MGMT activity in lung tissues. In the presence of such exposure, this variability in MGMT activity may alter cancer susceptibility, particularly as animal models have demonstrated that the complete absence of MGMT activity predisposes to alkylating-agent induced cancer while overexpression is protective. Recent studies have uncovered a series of polymorphisms that affect protein activity or are associated with differences in expression levels. The associations between these (and other) polymorphisms and cancer risk are inconsistent, possibly because of small sample sizes and inter-study differences in lung cancer histology. We have recently analysed a consecutive series of case-control studies and found evidence that lung cancer risk was lower in subjects with the R178 allele.
    • Lung colonization by Aspergillus fumigatus is controlled by ZNF77.

      Gago, S; Overton, Nicola L D; Ben-Ghazzi, N; Novak-Frazer, L; Read, N; Denning, D; Bowyer, P; Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, CTF Building, 46 Grafton Street, Manchester, M13 9NT (2018-09-20)
      Aspergillus fumigatus is a critical pathogen of humans. Exposure to A. fumigatus conidia occurs frequently but is normally cleared from the respiratory airways. In contrast, individuals with respiratory diseases are often highly colonized by fungi. Here, we use genome-edited epithelial cells to show that the genetic variant rs35699176 in ZNF77 causes loss of integrity of the bronchial epithelium and increases levels of extracellular matrix proteins. These changes promote A. fumigatus conidial adhesion, germination and growth. RNA-seq and LC/MS-MS analysis reveal rs35699176 upregulates vesicle trafficking leading to an increment of adhesion proteins. These changes make cells carrying rs35699176 more receptive to A. fumigatus in the early stages of infection. Moreover, patients with fungal asthma carrying rs35699176+/- have higher A. fumigatus loads in their respiratory airway. Our results indicate ZNF77 as a key controller of Aspergillus colonization and suggest its utility as a risk-marker for patient stratification.
    • Lymphatic vessel density, microvessel density and lymphangiogenic growth factor expression in colorectal cancer.

      Duff, Sarah E; Jeziorska, M; Kumar, Shant; Haboubi, Najib; Sherlock, David J; O'Dwyer, Sarah T; Jayson, Gordon C; Department of Surgery, Christie Hospital NHS Trust, Manchester, UK. saraheduff@aol.com (2007-11)
      OBJECTIVE: Microvessel density (MVD) has been studied as a prognostic marker in human cancers. Quantification of lymphatic vessel density (LVD) is now possible by using new antibodies. Expression of the lymphangiogenic growth factors, VEGF-C and VEGF-D, is associated with poorer clinicopathological outcomes in various tumours. The aim of this study was to quantify LVD and MVD in colorectal cancer, determine the relationship between LVD, MVD and clinicopathological variables and examine the relationship between LVD and tumour expression of VEGF-C and VEGF-D. METHOD: Thirty primary colorectal cancers were immunostained for CD34, lymph vessel endothelial hyaluronan receptor-1 (LYVE-1), VEGF-A and VEGF-D using standard techniques. LVD and MVD were determined by Chalkley grid counting. Tumours were assessed for the presence or absence of LYVE-1 positive lymphatics at different areas within the tumour and the tumour was scored for VEGF-C and VEGF-D immunostaining intensity at the invading tumour edge. Non-parametric tests were used for statistical analysis and a P-value of <0.05 was taken as significant. RESULTS: Lymph vessel endothelial hyaluronan receptor-1 was an excellent lymphatic vessel marker. Within normal bowel wall, lymphatic vessels were found rarely in the superficial colonic mucosa, but were numerous in the submucosa and muscularis propria. In the majority of tumours, lymphatic vessels were located in the peri-tumoural area, intra-tumoural vessels were sparse and tended to be narrow with closed lumina. At the invading tumour edge, VEGF-C expression was higher (P = 0.028) and VEGF-D expression lower (P = 0.011), in tumours in which lymphatic vessels were present. No significant differences between LVD and any clinicopathological variable or route of metastasis were identified. CONCLUSION: Lymphatic vessel density and MVD can be quantified in colorectal carcinoma using immunohistochemical techniques. The balance between expression of VEGF-C and VEGF-D at the invading tumour edge may enhance lymphatic metastasis, by promoting tumour lymphangiogenesis or by activation of pre-existing lymphatic vessels. No relationship was identified between LVD and clinicopathological variables.
    • Lymphocyte migration across high endothelium is associated with increases in alpha 4 beta 1 integrin (VLA-4) affinity.

      Hourihan, H; Allen, Terence D; Ager, A; Department of Cell and Structural Biology, University of Manchester, UK. (1993-04)
      The constitutive recirculation of lymphocytes between the widely distributed organs of the immune system is essential for host defence. We have developed an in vitro model of lymphocyte migration from the blood into lymph nodes which employs primary cultures of high endothelial cells (HEC). HEC-adherent lymphocytes adopt one of two distinct morphologies which correlates with their position in the endothelial layer; type I cells are bound to the surface of HEC and type II cells are underneath the endothelial layer. In a previous study we reported that the numbers of type I and type II cells are independently regulated, however the relationship between these two lymphocyte populations was not determined. In this study we have carried out detailed kinetic, phenotypic and functional analyses of type I and type II lymphocytes and determined their relationship. Using allotype marked lymphocytes from the PVG.RT7a and PVG.RT7b rat strains in a pulse-chase analysis, type I and type II lymphocytes were found to represent the same population of lymphocytes at different stages of interaction with the endothelial layer, rather than representing two independent lymphocyte populations. Migration was an irreversible event and the efficiency of migration (i.e. transition from type I to type II) was related to the concentration of lymphocytes plated on to the HEC layer. Following transmigration lymphocytes showed an increased ability to migrate across HEC layers and to bind to immobilised CS1 peptide. The increased binding to CS1 peptide was transient and fell to control levels over a 3 hour time period. The expression of alpha 4 integrin subunit on lymphocytes was unchanged following migration which suggests that the affinity of the CS1 receptor, alpha 4 beta 1, is upregulated by interaction with HEC. Together these results suggest that transendothelial migration is regulated by increases in the affinity of alpha 4 beta 1 integrin on lymphocytes following contact with HEC.
    • Lymphocyte migration into three-dimensional collagen matrices: a quantitative study.

      Schor, Seth L; Allen, Terence D; Winn, B; CRC Department of Medical Oncology, Christie Hospital and Holt Radium Institute, Manchester M20 9BX (1983-04)
      Lymphocytes have been plated onto the surface of three-dimensional gels of native collagen fibers, and their distribution throughout the three-dimensional collagen matrix has been determined in a quantitative fashion at various times thereafter. Information regarding the total number of applied cells may be obtained by this means. Lymphocyte penetration into the collagen gel does not appear to involve the expression of collagenolytic activity, nor does it require the presence of serum. Analysis of the kinetics of lymphocyte penetration into the gel matrix indicates that lymphocytes are migrating in a "random-walk" fashion. Our objective has been to establish a model system for studying the cell-matrix and cell-cell interactions which influence the pattern of lymphocyte recirculation in vivo and the results presented here are discussed in this context.
    • Lymphocyte radiosensitivity is a significant prognostic factor for morbidity in carcinoma of the cervix.

      West, Catharine M L; Davidson, Susan E; Elyan, S A; Valentine, Helen R; Roberts, Stephen A; Swindell, Ric; Hunter, Robin D; CRC Experimental Radiation Oncology Group, Paterson Institute for Cancer Research, Manchester, United Kingdom. cwest@picr.man.ac.uk (2001-09-01)
      PURPOSE: To study the relationship between pretreatment peripheral blood lymphocyte radiosensitivity and morbidity following radiation therapy. METHODS AND MATERIALS: A prospective study was carried out in which patients with carcinoma of the cervix underwent radiation therapy. Intrinsic radiosensitivity was measured on pretreatment peripheral blood lymphocytes, using a limiting dilution clonogenic assay. Late morbidity was assessed using the Franco-Italian glossary. Results were correlated in an actuarial analysis. RESULTS: There were no correlations between the measured lymphocyte radiosensitivity (SF2) and colony-forming efficiency, patient age, tumor grade, or disease stage. For 83 patients, lymphocyte SF2 was a significant prognostic factor for the probability of developing both any (p = 0.002) and Grade 3 (p = 0.026) morbidity. In 174 patients, stage showed borderline significance as a prognostic factor for morbidity (p = 0.056). However, the type of treatment (intracavitary alone, intracavitary plus parametrial irradiation, single insertion plus whole-pelvis irradiation) was significantly associated with the probability of developing late complications (p = 0.013). There was a weak significant inverse correlation between lymphocyte SF2 and grade of morbidity (r = -0.34, p = 0.002). CONCLUSION: These data highlight the importance of normal cell radiosensitivity as a factor determining radiation therapy response. They also show that peripheral blood lymphocyte SF2 is a highly significant prognostic factor for the probability of developing late radiation morbidity, and that carcinoma of the cervix is a good model for testing radiobiologic principles in the clinic.
    • Lymphocyte telomere length correlates with in vitro radiosensitivity in breast cancer cases but is not predictive of acute normal tissue reactions to radiotherapy.

      Iwasaki, Toshiyasu; Robertson, Naomi; Tsigani, Theodora; Finnon, Paul; Scott, David A; Levine, Edward; Badie, Christophe; Bouffler, Simon; Radiation Effects Department, Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Radiation Protection Division, Chilton, Didcot, Oxfordshire, UK. (2008-04)
      PURPOSE: To examine the hypothesis that lymphocyte telomere length may be predictive of both breast cancer susceptibility and severity of acute reactions to radiotherapy. MATERIALS AND METHODS: Peripheral blood lymphocyte cultures from breast cancer patients (with normal or severe skin reactions to radiotherapy) and normal individuals were assessed for in vitro radiosensitivity as measured by apoptosis, cell cycle delay and cytotoxicity. Telomere lengths were determined by a flow cytometric fluorescence in situ hybridization assay (FLOW-FISH). RESULTS: Female breast cancer cases (n = 24) had reduced lymphocyte telomere lengths by comparison with healthy controls (n = 20, p < 0.04). However, the average age of healthy controls was less (45.4) than cases (53). When the control group was modified to give a better age match (51.5, n = 13) the reduced telomere length in cases was not significantly different from controls. Lymphocytes from breast cancer cases also showed reduced cell cycle delay (p < 0.001) and increased apoptosis (p < 0.01) following irradiation in vitro at 3 and 5 Gy respectively, compared to healthy controls. Statistical significance was maintained with the improved age matching of groups. Comparison of lymphocytes from breast cancer patients with normal (n = 11) and severe (n = 13) skin reactions to radiotherapy failed to identify differences in telomere length or cellular radiosensitivity in this limited sample. CONCLUSIONS: This study adds to the evidence suggesting a correlation between altered cellular radiosensitivity and breast cancer. However, in the cases investigated, telomere length does not appear to be predictive of acute skin reactions to radiotherapy.