• The effect of age and menstrual cycle upon proliferative activity of the normal human breast.

      Potten, Christopher S; Watson, R J; Williams, G T; Tickle, S; Roberts, Stephen A; Harris, Martin; Howell, Anthony; Department of Epithelial Biology, Paterson Institute for Cancer Research, Manchester, UK. (1988-08)
      The aim of this study was to determine the proliferative activity within the epithelial cells of the normal human breast in 122 patients (6 reduction mammoplasties and 116 fibroadenoma excisions) in relation to age and the phase of the menstrual cycle. Thirty three of the patients were on oral contraceptives and 33 were parous. Thin tissue slices were incubated with tritiated thymidine and processed for autoradiography. Other samples were fixed directly and prepared for histology. The labelling, mitotic and apoptotic indices (LI, MI and AI) were determined and all illustrated considerable variability. The labelling indices are significantly (P less than 0.05) influenced by both patient age and stage during the menstrual cycle and ranged from 0-11.5%. Maximum LI values were obtained on the 20.8th day of the cycle. A square root transformation of the data was used to reduce the skewness of the data to a more normal distribution. The square root of the LI declined by 0.22 per decade. The mitotic data showed similar significant (P less than 0.05) correlations against age and day of cycle with a peak on the 21.5th day of the cycle, a decline by 0.072 per decade and a range from 0-0.6%. The data for apoptotic cells were less clearly influenced by the stage of the menstrual cycle but showed a significant (P less than 0.5) decline with age. The AI in parous patients was significantly higher than that in non-parous patients. There was no significant effect of oral contraceptives on any of the parameters measured when age and stage of cycle were taken into account. The considerable variability in the data could not be fully accounted for by either technical factors, the age of the patients, or the day of the cycle. We conclude that proliferation is negatively related to age and is influenced by the menstrual cycle but that additional as yet unknown factors must account for a large part of the variability seen in the data.
    • The effect of alpha4 beta1-integrin binding sequences of fibronectin on growth of cells from human hematopoietic progenitors.

      Schofield, Karen P; Humphries, M J; De Wynter, Erika A; Testa, Nydia G; Gallagher, John T; Departments of Medical Oncology and Experimental Haematology, Paterson Institute for Cancer Research, Manchester, UK. (1998-05-01)
      Highly regulated interactions between adhesion receptors on progenitor cells and their extracellular matrix ligands are essential for the control of hematopoiesis in bone marrow stroma. We have examined the relationship between alpha4beta1-integrin-mediated adhesion and growth of CD34(+) cells by assessing their adhesive and migratory patterns of proliferation in a mixture of hematopoietic growth factors in the presence of different recombinant fragments of the HepII/IIICS region of fibronectin. CD34(+) cells were isolated from cord blood and placed in culture wells containing serum-free medium and growth factors. Wells were precoated with either the H120 fragment of fibronectin, which contains three alpha4beta1-integrin binding sites, or the H0 fragment, which lacks the two highest affinity alpha4beta1 binding sequences. Proliferation of single cells of CD34(+)38(+)DR+ and CD34(+)38(-)DR+ phenotypes occurred in contact with the H120 substrate and was associated with migration. Larger numbers of cells were used to quantitate proliferative responses. Cells growing in wells coated with H120 formed attachments to the base of the wells throughout the culture period. Higher total cell counts were consistently found in wells coated with H120 compared with H0 and bovine serum albumin controls. The difference was first apparent at day 8 of culture and reached a maximum at days 11 through 13, when expansion with H120 was a mean of 1.8-fold higher than that seen with H0 (P
    • The effect of BCG stimulation on natural cytotoxicity in the rat.

      Potter, M R; Moore, Michael; Immunology Division, Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (1980-03)
      The natural cytotoxic activity of lymphoid cell populations from control and BCG-stimulated rats was examined using four target cell lines, K562, CCRF/CEM, Bri8 and Mc40. In control rats, the cytotoxicity of peritoneal cells was below that of spleen cells but above that of peripheral lymph node cells. Intraperitoneal injection of BCG induced a significant dose and time-dependent augmentation of cytotoxicity by peritoneal cells from W/Not and PVG/c rats, against all four cell lines. The increased activity reached a peak on days 4 and 5 after injection and returned to control levels by day 12. Spleen and lymph node cells from stimulated rats did not show increased cytotoxicity. K562 and CCRF/CEM target cells were considerably more susceptible to killing than Bri8 and Mc40 target cells. Separation of peritoneal cells from BCG-treated rats by density-gradient centrifugation gave an interface population, enriched with mononuclear cells showing high cytotoxic activity and a pellet population enriched with polymorphs showing very low activity. Nylon-fibre column filtration gave non-adherent and adherent cytotoxic populations. Cytotoxic activity was not diminished by removing cells adhering to Sephadex G10 or cells phagocytosing carbonyl iron, suggesting that much of the activity in this system was due to non-phagocytic mononuclear cell populations.
    • Effect of bcl-2 deficiency on the radiation response of clonogenic cells in small and large intestine, bone marrow and testis.

      Hoyes, Katherine P; Cai, W B; Potten, Christopher S; Hendry, Jolyon H; CRC Experimental Radiation Oncology Group, Paterson Institute for Cancer Research, Manchester, UK. khoyes@picr.man.ac.uk (2000-11)
      PURPOSE: Overexpression of bcl-2 protects against radiation induced apoptosis in lymphohaematopoietic cell types in vivo, whilst bcl-2 deficiency radiosensitizes murine T-lymphocytes in vitro. However, there are few data regarding the influence of bcl-2 deficiency on the radiosensitivity of non-lymphoid cell types. The purpose of this study was to investigate the role of bcl-2 in the clonogenic radiation response of intestinal crypts, bone marrow progenitor cells and testicular stem cells. METHOD: Survival curves were obtained for each cell type from bcl-2 null (-/-), heterozygote (+/-) and wild type (+/+) mice. Crypt survival in the small and large intestine was assessed using the crypt microcolony assay. Committed haemopoietic progenitors were assayed using in vitro colony-forming cell (CFC) assays and survival of clonogenic spermatogonia was assessed by scoring regenerative tubules at 35 days post-irradiation. RESULTS: There was no difference in small intestine crypt survival between the three genotypes. In the colon, there was a tendency towards lower clonogen survival in the +/- and -/- animals. Haemopoietic in vitro CFC from -/- animals showed lower survival in comparison to +/+ mice, but spermatogonial stem cells were comparatively more radioresistant. CONCLUSIONS: Deficiencies in bcl-2 affect the radiation response of different cell populations in small but different ways. This may be due to variations between cells in their innate capacity for apoptosis, their dependence on different members of the bcl-2 family gene and their cell-cycle status and p53 expression.
    • Effect of Campath-1H antibody on human hematopoietic progenitors in vitro.

      Gilleece, Maria H; Dexter, T Michael; Department of Experimental Haematology, CRC Paterson Institute for Cancer Research, Withington, Manchester, England. (1993-08-01)
      The humanized antibody CAMPATH-1H has been shown in pilot studies to be beneficial in the treatment of lymphoid malignancy and other lymphoproliferative diseases. The antigen recognized by this antibody is not confined to lymphoid cells, and work with rat antibodies of similar specificity has not eliminated the possibility of damage to human hematopoietic progenitors, particularly those capable of repopulating bone marrow and sustaining hematopoiesis. This study aimed to discover if hematopoietic progenitor cells were affected by treatment with CAMPATH-1H, with or without human complement. Bone marrow mononuclear cells from healthy volunteers were treated with saturating concentrations of CAMPATH-1H, human complement, or CAMPATH-1H plus human complement. The CD34-positive fraction of the mononuclear cells was treated similarly. Residual progenitor activity was measured in the colony-forming unit-granulocyte, erythroid, monocyte, megakaryocyte assay and compared with untreated controls. There was no significant difference (at the 5% level) between treated and control cells. Mononuclear cells were divided into CAMPATH-1H-positive and CAMPATH-1H-negative fractions by fluorescein isothiocyanate-CAMPATH-1H labeling and fluorescence-activated cell sorter separation. Hematopoietic progenitors were predominantly found in the CAMPATH-1H-negative fraction. Furthermore, mononuclear cells treated with CAMPATH-1H and complement were equivalent to controls in experiments that investigated the capacity of these cells to form hematopoietic foci in long-term cultures.
    • Effect of centrifugal forces on the structuredness of cytoplasm in growing yeast cells.

      Cercek, L; Cercek, B; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester, M20 9BX, England. (1973)
    • The effect of combined modality treatment with ionising radiation and TPPS-mediated photodynamic therapy on murine tail skin.

      Benstead, K; Moore, James V; Paterson Institute for Cancer Research, Christie Hospital, Manchester, UK. (1990-07)
      The effect on normal skin of combined modality treatment with 300 kV X-rays and photodynamic therapy (PDT) using the photosensitising drug meso-tetra (sulphonatophenyl) porphine (TPPS) was studied using the mouse tail necrosis assay. Prior treatment with a tolerance dose of PDT produced a significant increase in the probability of necrosis following graded doses of ionising radiation. A tolerance dose of X-rays administered prior to graded doses of PDT also produced a significant rise in the necrosis rate. TPPS appeared to have a radiosensitising effect but, as the animals were kept in subdued light, the low dose of PDT they therefore received may provide an alternative explanation. The effect of prolonging the interval between the modalities on the necrosis rate did not appear to be related to the time course of either the changes in blood flow produced by each modality, measured by xenon clearance studies or the development of the skin reaction following X-ray irradiation.
    • The effect of dibromodulcitol on resting and dividing lymphoid cells.

      Jeney, A; Fox, Brian W; Garrett, J V; Fox, Margaret; Holland, J; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester M20 9BX Great Britain (1976-12)
      The effect of dibromodulcitol (DBD) on the incorporation of labelled precursors into DNA and RNA fractions of PHA-stimulated human lymphocytes and of P388F lymphoma cells at various stages of their growth was studied. Both cell systems showed sensitivity to the drug within the concentration rage of 1-10 mug/ml. When DBD was added before phytohaemagglutinin (PHA), h.han RNA. In contrast, by adding DBD after PHA, RNA labelling was much more inhibited than DNA. In the latter case, the decrease in DNA labelling occurred only 24 h after drug treatment whereas RNA labelling was decreased 1 h after treatment. Levels of DBD which normally produced 30% inhibition in plating efficiency of P388F lymphoma cells affected uridine-5-T incorporation to a different extent at different stages of growth of the culture. Enhanced RNA labelling occurred in early exponential stage while at later stages of growth, RNA synthesis was depressed.
    • The effect of donor age on the proliferative response of human and mouse keratinocytes to phorbol, 12-myristate, 13-acetate.

      Parkinson, E Kenneth; Al-Yaman, Fadwa M; Appleby, Mark W; Department of epithelial biology, Paterson Institute for Cancer Research, CHristie Hospital and Holt Radium Institute Manchester M20 9BX, UK (1987-07)
      Epidermal keratinocytes grow clonally when provided with a 3T3 feeder layer and medium supplemented with 20% foetal bovine serum, hydrocortisone and cholera toxin. In this culture system the proliferative response of freshly isolated human and mouse keratinocytes to a short exposure (24 h) of the tumour promoter phorbol, 12-myristate, 13-acetate (PMA) was dependent on the donor age but was independent of the species or the biopsy site. Human keratinocytes from early (16-18 week) foetal donors displayed a strong proliferative response to PMA as determined by a 5- to 7-fold increase in colony number and an increase in the average colony size. In contrast, adult and juvenile keratinocytes of all ages from both mice and humans displayed an inhibition of colony forming efficiency and a reduction in colony size. When continuously passaged in culture human foetal keratinocytes gradually changed the pattern of their response to PMA so that they were inhibited from growing rather than being stimulated and after 21 days (three passages) their response was quantitatively similar to juvenile keratinocytes. Co-culture of juvenile keratinocytes with irradiated foetal keratinocytes did not alter their response to PMA so that the observed proliferative response of foetal keratinocytes to PMA is not readily explained by the autosecretion of mitogens or other regulatory molecules by these cells. Late foetal (17 days gestation), neonatal and post-neonatal (5-10 days old) mouse keratinocytes were also inhibited from growing by PMA but the magnitude of the effect was directly related to the age of the mouse and was in all cases less than that observed with adult mice. The relationship of these results to the mechanism of action of phorbol esters in epidermis is discussed.
    • Effect of enkephalins on bone marrow cells.

      Krizanac-Bengez, L; Boranic, M; Testa, Nydia G; Marotti, T; Department of Experimental Biology and Medicine, Ruder Boskovic Institute, Zagreb, Croatia. (1992)
      Mouse bone marrow cells were incubated with methionine- or leucine-enkephalin (10(-15)-10(-6) M) before seeding into soft agar cultures. In marrow samples harvested at different times, enkephalins decreased GM colony count on average by 30-40%. In individual experiments, however, the same concentration of enkephalins caused even stimulation, or at other times had effect. In view of the circadian periodicity of neuroendocrine functions and hematopoietic activity, the enkephalin effect on bone marrow cells was tested on marrow samples harvested at fixed time points (6 am, 6 pm), using enkephalin concentrations in the physiological range (10(-12)-10(-9) M). The seeding efficiency of the 6-pm cell population was on average 50% above that of the 6-am population. The 6-pm cell population was also more susceptible to the inhibitory effect of the enkephalins (35% inhibition) than the 6-am population (15% inhibition), and the variability in response was considerably reduced. With progenitor cell-enriched population, obtained by fluorescence-activated cell sorting (FACS) of 6-am bone marrow samples, in 3 out of 6 experiments Met- and Leu-enkephalin showed 30-35% inhibition of GM colony formation over a wide range of concentrations (10(-15)-10(-6)). In the other 3 experiments, suppression as well as stimulation or no alteration in colony count were observed. This variability probably reflected quality (purity) of the progenitor cell population, and may indicate that the enkephalins affected hematopoietic cells via a population of accessory cells.
    • Effect of epidermal growth factor receptor tyrosine kinase inhibition on epithelial proliferation in normal and premalignant breast.

      Chan, Kai C; Knox, W Fiona; Gee, Julia M; Morris, Julie; Nicholson, Robert I; Potten, Christopher S; Bundred, Nigel J; Department of Surgery, University Hospital of South Manchester, United Kingdom. (2002-01-01)
      The factors controlling epithelial proliferation in ductal carcinoma in situ (DCIS) are unclear. Antiestrogens are effective in the prevention of the majority of estrogen receptor-positive, but not estrogen receptor (ER)-negative breast cancers, which suggests that other factor(s) are promoting proliferation in ER-negative DCIS. Mutated or overexpressed tyrosine kinases are frequently associated with tumor development. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is involved with mitogenesis and is expressed in ER-negative DCIS. We hypothesized that EGFR is central in driving proliferation in ER-negative/EGFR-positive DCIS. The purpose of this study was to establish whether the EGFR tyrosine kinase inhibitor (EGFR-TKI), ZD1839 (Iressa), can reduce epithelial proliferation and increase apoptosis in EGFR-positive DCIS. Breast tissue from 16 women undergoing surgery for DCIS were implanted into 16-32 immunosuppressed mice/experiment (8 xenografts/mouse). Treatment commenced 2 weeks after implantation and consisted of once daily oral gavage with ZD1839 at doses ranging from 10 to 200 mg/kg for 14-28 days; appropriate controls were present. Xenografts were removed on days 14, 21, 28, and 42 after implantation and then assessed for proliferation (LI) by Ki67 immunostaining and apoptosis index (AI) by morphology. All Ps reported are two-sided. Overall, a 56% reduction in epithelial proliferation was seen with Iressa in EGFR-positive DCIS. EGFR-TK inhibition compared with vehicle controls resulted in a fall in Geometric Mean Labeling Index (LI) after 14 days (day 28) of treatment both in ER-negative/EGFR-positive DCIS [6.5% interquartile range (IQR, 3.8-11.1) versus 13.9% (IQR, 12.0-16.3%); F(1,3) = 103; P = 0.002] and ER-positive/EGFR-positive DCIS [4.6% (IQR, 3.9-5.2%) versus 11.7% (IQR, 9.2-15.5); F(1,2) = 32.3; P = 0.03]. EGFR-TK inhibition had similar effects on the "at risk" normal breast epithelium adjacent to DCIS in the treated epithelium LI day 28 [ZD1839 2.2% (IQR, 1.7-3.3%) compared with control 3.8% (IQR, 2.4-5.4%); F(1,14) = 29.2; P = 0.00009] and in addition increased epithelial apoptotic index at day 21 [ZD1839 0.38 (0.23-0.83) compared with control 0.19 (0.1-0.25); F(1,6) = 12.2; P = 0.013]. The effect on epithelial proliferation was still significant after 28 days of treatment [for both DCIS (F1,29) = 24; P = 0.039 and normal breast F(1,6) = 47.3; P = 0.0005]. EGFR-TK inhibition with ZD1839 offers a novel approach to the treatment of EGFR-positive DCIS, regardless of ER status, and provides a potential new chemopreventative approach in patients at high risk of breast cancer.
    • The effect of exogenous prostaglandin administration on tumor size and yield in Min/+ mice.

      Wilson, James W; Potten, Christopher S; Section of Cell and Tumour Biology, Paterson Institute for Cancer Research, Manchester, United Kingdom. jwilson@picr.man.ac.uk (2000-08-15)
      This study set out to examine the effect of exogenous prostaglandin (PG) administration on tumor development in Min/+ mice. Mice were treated with the stable prostaglandin E2 analogue 16,16-dimethyl-PGE2 from 6-18 weeks of age. Mice were sacrificed, and tumor burden was assessed using morphometric techniques. Parameters measured were median tumor size, mean tumor size, the proportion of the area of the gastrointestinal mucosa covered with tumor, and the number of tumors per 1000 mm2 of gastrointestinal mucosa. In addition, proliferative and apoptotic indices were determined. These measurements were carried out for all regions of the small intestine (i.e., duodenum, jejunum, upper ileum, and lower ileum) and the large intestine (i.e., cecum and mid-colon/rectum). 16,16-Dimethyl-PGE2-treated animals showed a significant decrease in tumor burden (by approximately 50-70%), in comparison with those animals that were treated with vehicle alone (0.001% ethanol in 0.9% sterile saline), in all regions of the intestine (at P = 0.008 or better). This effect was contributed to by a reduction in the number of tumors (by approximately 20-50%) and a reduction in tumor size (by approximately 10-70%). An increase in tumor cell turnover was associated with this decrease in tumor burden, as determined by the changes in the levels of thymidine incorporation (significant at P = 0.003), apoptosis, and mitosis (nonsignificant).
    • Effect of expression of the Escherichia coli nth gene in Saccharomyces cerevisiae on the toxicity of ionizing radiation and hydrogen peroxide.

      Skorvaga, M; Cernáková, L; Chovanec, M; Vlasáková, D; Kleibl, K; Hendry, Jolyon H; Margison, Geoffrey P; Brozmanová, J; Laboratory of Molecular Genetics, Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava 37, Slovak Republic. (2003-09)
      PURPOSE: To examine the contribution of endonuclease III (Nth)-repairable lesions to the cytotoxicity of ionizing radiation (IR) and hydrogen peroxide (H2O2) in the yeast Saccharomyces cerevisiae. MATERIALS AND METHODS: A selectable expression vector containing the E. coli nth gene was transformed into two different wild-type strains (7799-4B and YNN-27) as well as one rad52 mutant strain (C5-6). Nth expression was verified by Western analysis. Colony-forming assay was used to determine the sensitivity to IR and H2O2 in both stationary and exponentially growing cells. RESULTS: The pADHnth-transformed wild-type (77994B) strain was considerably more resistant than vector-only transformants to the toxic effects of IR, in both stationary and exponential growth phases, although this was not the case in another wild-type strain (YNN-27). In contrast, there were no significant effects of nth expression on the sensitivity of the wild-type cells to H2O2. Moreover, nth expression caused no effects on the H2O2 sensitivity in the rad52 mutant cells, but it led to a slight increase in sensitivity in these cells following IR, particularly at the highest dose levels used. CONCLUSIONS: Whilst other damage-processing systems may play a role, DNA lesions that are substrates for Nth can also make a contribution to the toxic effects of IR in certain wild-type yeast. Hence, DNA double-strand breaks should not be considered the sole lethal lesions following IR exposure.
    • The effect of fractionation of light treatment on necrosis and vascular function of normal skin following photodynamic therapy.

      Benstead, K; Moore, James V; Paterson Institute for Cancer Research, Christie Hospital and Holt Radium Institute, UK. (1988-09)
      Sparing of normal tissue, mouse tail skin, by fractionation of light treatment in photodynamic therapy has been demonstrated in BDF1 mice injected with 2 mg tetrasodium-meso-tetra(4-sulphophenyl)porphine dodecahydrate i.v. When the time between 2 fractions of 67.5 J cm-2 and 90 J cm-2 was increased to 2 and 4 days respectively the incidence of necrosis fell to that expected after a single fraction. Blood flow in the tail skin 5 days after the second light fraction, as measured by the clearance of an intradermally injected solution of 133xenon in 0.9% saline, returned to control values when the time between 2 fractions was 2 days with 67.5 J cm-2 fractions, and 3 days with 90 J cm-2 fractions. The time course of recovery of normal mouse tail skin from photodynamic therapy, as shown by these split dose experiments, was found to be similar to the time course for the recovery of blood flow following a single light treatment.
    • Effect of haemopoietic stem-cell proliferation regulators on early and late spleen colony-forming cells.

      Wright, Eric G; Lorimore, S A; Lord, Brian I; Paterson Laboratories, The Christie Hospital and Holt Radium Institute, Manchester, M20 9BX, UK. (1985-03)
      An inhibitor and stimulator of CFU-s proliferation can be obtained from haemopoietic tissue containing, respectively, relatively quiescent CFU-s (e.g. normal bone marrow) and proliferating CFU-s (e.g. regenerating bone marrow). Their effects on the proliferative behaviour of steady-state and regenerating marrow CFU-s, which produce colonies 7, 10 and 12 days post-transplantation have been investigated. The results demonstrate changing sensitivities of CFU-s to inhibitor and stimulator as they progress through a developmental age structure, 'Older' CFU-s (producing early spleen colonies) are more sensitive to stimulator, 'Younger' CFU-s (producing late spleen colonies) are more sensitive to inhibitor.
    • The effect of hormone induced stress upon the extent of alkylation of rat liver nucleic acids by N-methyl-N-nitrosourea.

      Magin, M N; O'Connor, Peter J; Craig, A W; Margison, Geoffrey P; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (1975-11-25)
      An examination was made of the effect of treatment with methylating agents of varying carcinogenic potency and with stress inducing hormones upon DNA synthesis in the resting liver of the rat. With the methylating agents an early stimulation of DNA synthesis was observed, but this was depressed below the control levels at later times and with higher doses; hormone administration also resulted in a depression of DNA synthesis but, without any initial stimulation at the dosage employed. Under conditions of induced stress it was found that the extent of reaction of N-methyl-N-nitrosourea with cellular macromolecules was enhanced. This appeared to be a general effect upon the liver cell since both DNA and rRNA were affected in a similar manner.
    • Effect of hydrocortisone on osteoclasts generated in cat bone marrow cultures.

      Suda, T; Testa, Nydia G; Allen, Terence D; Onions, D; Jarrett, O; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Withington, Manchester M20 9BX (1983)
      The generation of osteoclasts in cultures of cat bone marrow was completely inhibited for 4 weeks with 10(-6)M hydrocortisone (HC) and partially inhibited with 10(-7) to 10(-9)M in a dose-dependent fashion. This effect was completely reversible when cultures were exposed for only 2 weeks to 10(-9) or 10(-8)M HC. However, cultures in which higher concentrations (10(-7) to 10(-5)M) were maintained for the same period did not show complete recovery in terms of numbers of osteoclasts and number of nuclei per cell after withdrawal of HC, suggesting that precursor cells of osteoclasts were also damaged by HC. To study the effects of HC on osteoclasts already present in the cultures, 10(-6)M was added to 4-week-old untreated cultures. The number of osteoclasts decreased rapidly and a gross morphological response was also apparent (rounding of the cells leading to detachment from the substratum and inhibition of cell fusion), indicating that the generation as well as the survival of osteoclasts in vitro are sensitive to HC. The morphological changes observed under optical and electron microscopy correspond to those of the reported inactive form of osteoclasts, and suggest that their function may also be altered by HC.
    • The effect of ifosfamide and its metabolites on intracellular glutathione levels in vitro and in vivo.

      Lind, Michael J; McGown, Alan T; Hadfield, John A; Thatcher, Nick; Crowther, Derek; Fox, Brian W; CRC Department of Medical Oncology, Paterson Institute for Cancer Research, Christie Hospital, Manchester, U.K. (1989-06-01)
      The effect of ifosfamide and its metabolites on intracellular levels of glutathione in P388 cells in vitro has been studied. It is demonstrated that glutathione depletion occurs only in the presence of 4-hydroperoxyifosfamide and chloroacetaldehyde. In contrast isophosphoramide mustard had no effect on glutathione levels in intact cells. The concentration of 4-hydroperoxyifosfamide required to reduce glutathione levels by 50% was approximately 1 mM and this represents a concentration far in excess of that achievable in patients receiving the drug. However the concentration of chloroacetaldehyde (approximately 100 microM) required to reduce intracellular levels of glutathione to a similar extent is attained in patients receiving ifosfamide. The glutathione levels in lymphocytes isolated from a patient undergoing an eight hour infusion of ifosfamide showed a marked decrease to about 30% of their original value. We conclude that ifosfamide causes glutathione depletion in vivo and the majority of this can be accounted for by the production of chloroacetaldehyde.
    • Effect of in vivo administration of interferon gamma on expression of MHC products and tumour associated antigens in patients with metastatic melanoma.

      Ghosh, Anna K; Cerny, T; Wagstaff, John; Thatcher, Nick; Moore, M; Department of Immunology, Paterson Institute for Cancer Research, Manchester, U.K. (1989-11)
      IFN-gamma is an effective inducer of MHC class II antigen expression in cell lines of malignant melanoma. To investigate the possibility that IFN-gamma may increase MHC class I and II and melanoma tumour associated antigens in vivo, immunohistochemical analyses of biopsies from six patients with metastatic disease undergoing IFN-gamma treatment were performed. Before IFN-gamma treatment, the melanomas were class I positive and class II negative. After treatment, class I expression was neither enhanced nor class II expression induced in any tissue sample regardless of biopsy time or dose of IFN-gamma. TAA was similarly unchanged. However, in one of the six patients a primary cell line was established and IFN-gamma induced expression of MHC products. The possible reasons for lack of MHC induction are discussed, although qualitative changes in antigen expression cannot be excluded on the basis of qualitative immunocytochemical techniques alone.
    • The effect of increasing the treatment time beyond three weeks on the control of T2 and T3 laryngeal cancer using radiotherapy.

      Slevin, Nicholas J; Hendry, Jolyon H; Roberts, Stephen A; Agren-Cronqvist, A; Department of Radiotherapy, Christie Hospital Cancer Research Campaign, Manchester, UK. (1992-08)
      Local control of cancer by radiotherapy may be prejudiced by accelerated tumour clonogen repopulation particularly during protracted treatment schedules. A series of 496 cases of T2 and T3 larynx cancer treated here by radiotherapy has been studied to examine the impact on local control of treatment durations ranging from 9 to 41 days. Data were analysed using a linear-quadratic formulation describing the fractionation sensitivity, with the incorporation of a parameter relating to treatment time. Using combined T2 and T3 data, the increase in dose required to maintain a constant local control (the time factor) was between 0.5 and 0.6 Gy per day. These values are similar to those reported for 4 weeks or more in the literature. Also, the calculated dose to control 50% of tumours, given over the standard Christie duration of 21 days, was on the line projected back from literature data over 28-66 days. The present data are consistent with the presence of such a time factor following a lag phase of not more than 3 weeks after starting radiotherapy. Hence, further consideration should be given to using shorter overall treatment times in radiotherapy for head and neck cancer.