• Role of heparan sulfate-2-O-sulfotransferase in the mouse.

      Merry, Catherine L R; Wilson, Valerie A; Cancer Research Campaign, Department of Medical Oncology, Christie Hospital NHS Trust, Manchester, United Kingdom. (2002-12-19)
      Heparan sulfate (HS) is a long unbranched polysaccharide found covalently attached to various proteins at the cell surface and in the extracellular matrix. It plays a central role in embryonic development and cellular function by modulating the activities of an extensive range of growth factors and morphogens. HS 2-O-sulfotransferase (Hs2st) occupies a critical position in the succession of enzymes responsible for the biosynthesis of HS, catalysing the transfer of sulfate to the C2-position of selected hexuronic acid residues within the nascent HS chain. Previous studies have concluded that 2-O-sulfation of HS is essential for it to cooperate in many growth factor/receptor interactions. Surprisingly therefore, embryos lacking functional Hs2st survive until birth, but die perinatally, suffering complete failure to form kidneys. However, this rather late lethality belies a more intricate involvement of 2-O-sulfated HS during development. The purpose of this review is to summarise the requirements for 2-O-sulfated HS during mouse development, at the morphological and molecular level. The implications that altered HS structure may have on growth factor/receptor signalling in vivo will be discussed.
    • The role of human papillomavirus vaccines in cervical neoplasia.

      Stern, Peter L; Faulkner, Rebecca L; Veranes, Emma C; Davidson, Emma J; Immunology Department, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, M20 4BX, UK. (2001-10)
      Cervical cancer is the second most common cause of cancer-related death in women, in some developing countries accounting for the highest cancer mortality. The evidence for the association of high-risk human papillomavirus types with the aetiology of cervical neoplasia is firmly established, human papillomavirus being detected in virtually all cervical cancers. The risk of progression of precursor cervical intra-epithelial neoplasia lesions is associated with persistence of human papillomavirus infection. One strategy for the management of cervical neoplasia worldwide could be the development of prophylactic and/or therapeutic human papillomavirus vaccines. This chapter will discuss the natural history of human papillomavirus infection, viral immunity and the clinical course of resultant disease as the background to the effective design and use of human papillomavirus vaccines for protection or therapy. The progress of ongoing phase I and II clinical trials for several different vaccine preparations and the challenges for establishing their future use will be discussed.
    • Role of interleukin-3 in the regulation of intracellular K+ homeostasis in cultured murine haemopoietic cells.

      Laskay, Gabor; Várhelyi, T; Dale, Robert E; Dexter, T Michael; Department of Physics and Instrumentation, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, U.K. (1995-09-14)
      Comparative fluorimetric, flow cytofluorimetric and fluorescence ratiometric determinations of intracellular K+ concentrations in murine haemopoietic cells (FDCP-Mix clone A4) cultured in the presence and absence of the specific growth factor Interleukin-3 were carried out with the fluorescent potassium-binding benzofuran-isophthalate acetoxymethyl ester probe. Cell suspensions kept in the absence of Interleukin-3 for 5 hours exhibited lower fluorescence intensities and smaller fluorescence ratios than their growth-factor-replete counterparts, an effect found to be reversible by readdition of the growth factor. It is concluded that Interleukin-3 deprivation of these cells leads to loss of intracellular K+. It is tentatively suggested that this deprivation-induced K+ loss might be associated with an early event in apoptotic cell death.
    • Role of MDR1 and MRP1 in trophoblast cells, elucidated using retroviral gene transfer.

      Atkinson, Diane E; Greenwood, Susan L; Sibley, Colin P; Glazier, Jocelyn D; Fairbairn, Leslie J; Academic Unit of Child Health, University of Manchester, St Mary's Hospital, Hathersage Rd., Manchester M13 OJH, United Kingdom. diane.e.atkinson@man.ac.uk (2003-09)
      Natural differences in expression and retroviral transduction techniques were used to test the hypothesis that MDR1 P-glycoprotein (P-gp) and MRP1 (multidrug resistance-related protein) contribute to xenobiotic handling by placental trophoblast. RT-PCR and Western blotting in placenta, primary cytotrophoblast cell cultures, and BeWo, JAr, and JEG choriocarcinoma cell lines showed that MRP1 was ubiquitously expressed, whereas MDR1 was absent or minimally expressed in BeWo and JEG cell lines. In syncytiotrophoblast, P-gp was localized predominantly to the microvillous, maternal facing plasma membrane, and MRP1 to the basal, fetal facing plasma membrane. Functional studies showed that cyclosporin A-sensitive accumulation of [3H]vinblastine by cells containing both transport proteins was significantly different from those expressing predominantly MRP1. Retroviral gene transfer of MDR1 to BeWo cells confirmed that this difference was due to the relative expression of MDR1. Therefore, both P-gp and MRP1 contribute to xenobiotic handling by the trophoblast. Localization of P-gp to the microvillous membrane suggests an essential role in preventing xenobiotic accumulation by the syncytiotrophoblast and, therefore, in protecting the fetus.
    • The role of metallothionein, glutathione, glutathione S-transferases and DNA repair in resistance to platinum drugs in a series of L1210 cell lines made resistant to anticancer platinum agents.

      Hrubisko, M; McGown, Alan T; Fox, Brian W; CRC Dept of Experimental Chemotherapy, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, U.K. (1993-01-07)
      The glutathione contents, glutathione S-transferase activities and metallothionein contents have been measured in a series of L1210 cell lines which show decreased sensitivities to platinum drugs. Resistance to cisplatinum cisDDP, cis-diamminedichloroplatinum (II)] and chip [ioproplatin, cisdichloro-bis-isopropylamine-trans dihydroxy platinum IV] was found to correlate with glutathione levels but not metallothionein. Conversely, resistance to tetraplatin was found to be correlated with metallothionein but not glutathione levels. However, depletion of glutathione by buthionine 1-sulphoximine sensitizes all cell lines to the effects of cisDDP, chip and tetraplatin [d,1-trans-tetrachloro-1,2-diamino-cyclohexanplatinum (IV)]. Inhibition of DNA repair by aphidicholin or caffeine also partially restored sensitivity to these platinum drugs. These results indicate the complexity of the changes occurring upon the development of drug resistance.
    • The role of MHC class I expression in developmental tumours.

      Stern, Peter L; Rinke de Wit, T F; Department of Immunology, Paterson Institute for Cancer Research, Manchester, UK. (1991-02)
      Expression of HLA class I (-like) genes by two developmental tumour cell lines representing embryonic (Tera-2) and extra-embryonic (Jeg-3) origins is reviewed. The Tera-2 embryonal carcinoma cells are HLA negative but can be induced by gamma interferon to express HLA-A, -B, -C, and apparently -E and G genes. Jeg-3 choriocarcinoma cells constitutively express HLA-G and low levels of a novel HLA-C gene product. The NK sensitivity of the developmental tumour cell types has been assessed and the biochemical characteristics of the surface molecules expressed by the trophoblast derived cells has been further documented. The biological role of these novel HLA molecules in the context of the maternal acceptance of the fetal-semi-allograft is discussed.
    • Role of MHC class-I antigens and the CD3 complex in the lysis of autologous human tumours by T-cell clones.

      Roberts, T E; Shipton, U; Moore, Michael; epartment of Immunology, Paterson Institute for Cancer Research, Christie Hospital and Holt Radium Institute, Manchester M200 9BX, UK (1987-04-15)
      Peripheral blood lymphocytes (PBL) of 4 patients with malignant effusions were stimulated for 6 days with purified autologous tumour cells, before isolation of the lymphoblasts and cloning by limiting dilution in interleukin-2 (IL-2). Forty-five clones were analyzed for cytotoxicity (CTX) against autologous, allogeneic tumour and erythromyeloid K562 cells of known status with respect to expression of major histocompatibility complex (MHC) antigens, estimated by reaction with the W6/32 (anti HLA, -A, -B, -C monomorphic) and TDR 31.1 (anti HLA-DR) monoclonal antibodies (MAb). All 45 clones were CD3+. Twenty-five (56%) of them were cytotoxic for at least one target; 24 were autoreactive (restricted in 7); 17 were alloreactive; 16 were K562 reactive. Under comparable conditions autoreactivity was partially blocked by W6/32 in 12/20 effector:target combinations; alloreactivity in 8/13 and K562 reactivity in 0/14. Modulation of effector cell surface CD3 antigens by OKT3 monitored by flow cytometry reduced autoreactivity in 9/14 combinations, alloreactivity in 2/6 and K562 reactivity in 0/4. W6/32 blocking and T3 modulation of cytotoxicity were almost invariably concordant against the same target. The data suggest that, to accomplish lysis of autologous and allogeneic tumour targets, certain clones require MHC recognition and a functional CD3 complex, while for others with similar target cell repertoires, there is no such requirement. It is possible that T-cell clones responding to a tumour-associated antigen (TAA) in the context of self MHC antigens can also respond to an allogeneic class-I product in the absence of TAA, and/or that aberrant class-I antigen expression on autologous tumours accounts for the alloreactivity.
    • Role of microRNAs in chemoresistance.

      Magee, Peter; Shi, Lei; Garofalo, Michela; Transcriptional Networks in Lung Cancer Group, Cancer Research UK Manchester Institute, University of Manchester, Wilmslow Road, Manchester, M20 4BX (2015-12)
      Drug resistance is a major problem in the treatment of cancer patients. Resistance can develop after prolonged cycles of chemotherapy or can be present intrinsically in the patient. There is an emerging role of microRNAs (miRNAs) in resistance to cancer treatments. miRNAs are small non-coding RNAs that are evolutionarily conserved and also involved as regulators of gene expression through the silencing of mRNA targets. They are involved in many different cancer types and a plethora of mechanisms have been postulated for the roles that miRNAs play in the development of drug resistance. Hence, miRNA-based gene therapy may provide a novel approach for the future of cancer therapy. This review focuses on an overview of recent findings on the role of miRNAs in the resistance to chemotherapy in different tumours.
    • Role of mitochondrial membrane permeabilization in apoptosis and cancer.

      Henry-Mowatt, Judith; Dive, Caroline; Martinou, Jean-Claude; James, Dominic I; Cellular and Molecular Pharmacology Group, The Paterson Institute for Cancer Research, Wilmslow Road M20 4BX, Manchester, UK. (2004-04-12)
      The release of proteins from the intermembrane space of mitochondria is one of the pivotal events in the apoptotic process, which can lead to the activation of caspases and the ultimate demise of the cell. How these proteins exit the mitochondria is still a matter of intense debate. Here, we discuss the possible mechanisms behind the release of apoptogenic proteins, the ways in which cancer cells subvert these mechanisms, and the therapeutic regimens that aim to promote the timely loss of integrity of the outer mitochondrial membrane.
    • The role of non-genetic information in evolutionary frameworks

      Moran, Katherine L; Shlyakhtina, Yelyzaveta; Portal, Maximiliano M; Cell Plasticity & Epigenetics Lab, Cancer Research UK - Manchester Institute, The University of Manchester, Manchester, UK. (2021)
      The evolution of organisms has been a subject of paramount debate for hundreds of years and though major advances in the field have been made, the precise mechanisms underlying evolutionary processes remain fragmentary. Strikingly, the majority of the core principles accepted across the many fields of biology only consider genetic information as the major - if not exclusive - biological information carrier and thus consider it as the main evolutionary avatar. However, the real picture appears far more complex than originally anticipated, as compelling data suggest that nongenetic information steps up when highly dynamic evolutionary frameworks are explored. In light of recent evidence, we discuss herein the dynamic nature and complexity of nongenetic information carriers, and their emerging relevance in the evolutionary process. We argue that it is possible to overcome the historical arguments which dismissed these carriers, and instead consider that they are indeed core to life itself as they support a sustainable, continuous source of rapid adaptation in ever-changing environments. Ultimately, we will address the intricacies of genetic and non-genetic networks underlying evolutionary models to build a framework where both core biological information concepts are considered non-negligible and equally fundamental.
    • Role of nonmyeloablative allogeneic stem-cell transplantation after failure of autologous transplantation in patients with lymphoproliferative malignancies.

      Branson, Kate; Chopra, Rajesh; Kottaridis, Panagiotis D; McQuaker, Grant; Parker, Anne; Schey, Stephen; Chakraverty, Ronjon; Craddock, Charles; Milligan, Donald W; Pettengell, Ruth; et al. (2002-10-01)
      PURPOSE: Conventional allogeneic stem-cell transplantation (SCT) after a prior failed autograft is associated with a transplant-related mortality rate of 50% to 80%. The aim of the current study was to evaluate the safety and efficacy of sibling, HLA-matched, nonmyeloablative allogeneic SCT with donor lymphocyte infusion (DLI) in patients with lymphoid malignancy after failure of autologous SCT. PATIENTS AND METHODS: A total of 38 patients with refractory, progressive, or relapsed disease after autologous SCT were entered onto this study. The conditioning regimen consisted of the humanized monoclonal antibody CAMPATH-1H, fludarabine, and melphalan. Fifteen of 35 assessable patients received DLI after SCT. RESULTS: Sustained neutrophil engraftment was achieved in 37 recipients, and platelet engraftment was achieved in 35 patients. The estimated transplant-related mortality was 7.9% at day 100 and 20% at 14 months, the median duration of follow-up. Eight patients experienced grade I/II acute graft-versus-host disease (GVHD) after transplantation, but no grade III/IV GVHD was observed in this setting. However, grade III/IV GVHD occurred in seven patients who received DLI. The actuarial overall survival at 14 months was 53%, with a progression-free survival of 50%. DLI produced a further response in three of 15 recipients. CONCLUSION: Nonmyeloablative allogeneic SCT after CAMPATH-1H-containing conditioning is a relatively safe option compared with conventional allogeneic transplantation for patients who have failed previous autologous SCT. The low incidence of early GVHD enabled the subsequent administration of DLI to improve further clinical responses in this poor-risk group of lymphoma and myeloma patients.
    • Role of nucleotide excision repair in processing of O4-alkylthymines in human cells.

      Klein, J C; Bleeker, M J; Roelen, H C; Rafferty, Joseph A; Margison, Geoffrey P; Brugghe, H F; Van den Elst, H; Van der Marel, G A; Van Boom, J H; Kriek, E; et al. (1994-10-14)
      O4-Alkylthymines have been implicated as potential carcinogenic DNA lesions. We have studied the effects of O4-methylthymine, O4-ethylthymine, and O4-n-propylthymine in a model system in which a single lesion was located at a defined position on a SV40-based shuttle vector and have found large differences in the effects of these lesions in repair-proficient and nucleotide excision repair-deficient cells. In repair-competent human HeLa cells, normal fibroblasts, and XP-A (2OS) revertant cells, all 3 residues were highly mutagenic; a mutation frequency of approximately 20% was found for both O4-methylthymine and O4-ethylthymine, whereas that of O4-n-propylthymine was approximately 12%. These frequencies were independent of the activity of the O6-alkylguanine DNA alkyltransferase. All three O4-alkylthymines induced T-->C transitions exclusively. In nucleotide excision repair-deficient XP-A cells, however, these lesions were not mutagenic but strongly inhibited plasmid replication (> 90%). These results indicate that O4-alkylthymines are efficiently recognized by the nucleotide excision repair system and cause a complete cessation of plasmid replication if this system is deficient. Nevertheless, proficiency in the nucleotide excision repair pathway correlates with a high frequency of mutation induction by these lesions.
    • Role of O6-alkylguanine-DNA alkyltransferase in the resistance of mouse spermatogenic cells to O6-alkylating agents.

      Thompson, M J; Abdul-Rahman, S; Baker, T G; Rafferty, Joseph A; Margison, Geoffrey P; Bibby, M C; Clinical Oncology Unit, University of Bradford, Bradford BD7 1DP, UK. (2000-07)
      The O(6)-alkylguanine-DNA alkyltransferase inactivator O(6)-benzylguanine was administered to BALB/c mice either alone or before exposure to 1,3-bis(2-chloroethyl)-1-nitrosourea to study the role of the DNA repair protein O(6)-alkylguanine-DNA alkyltransferase in the protection of the testis against anti-cancer O(6)-alkylating agents. Exposure of the mice to 1, 3-bis(2-chloroethyl)-1-nitrosourea or O(6)-benzylguanine alone did not produce any marked testicular toxicity at the times studied. Testicular O(6)-alkylguanine-DNA alkyltransferase concentrations were assayed between 0 and 240 min after O(6)-benzylguanine treatment and were shown to be > 95% depleted 15 min after treatment with O(6)-benzylguanine and remained at > 95% at all the times assayed. Histological examination, the reduction in testicular mass and the induction of spermatogenic cell apoptosis showed that this depletion significantly potentiated 1, 3-bis(2-chloroethyl)-1-nitrosourea-induced testicular damage after treatment. Major histological damage was apparent 42 days after treatment, demonstrating that the stem spermatogonia were significantly affected by the combination. These results demonstrate that O(6)-alkylguanine-DNA alkyltransferase plays a significant role in protecting the spermatogenic cells from damage caused by DNA alkylation and indicate that the observed toxicity may result from damage to stem spermatogonia.
    • The role of oestrogen and progesterone receptors in human mammary development and tumorigenesis.

      Anderson, Elizabeth; Tumour Biochemistry Laboratory, Christie Hospital NHS Trust, Manchester, UK. eanderson@picr.man.ac.uk (2002)
      A relatively small number of cells in the normal human mammary gland express receptors for oestrogen and progesterone (ER and PR), and there is almost complete dissociation between steroid receptor expression and proliferation. Increased expression of the ER alpha (ERalpha) and loss of the inverse relationship between receptor expression and proliferation occur at the very earliest stages of tumorigenesis, implying that dysregulation of ERalpha expression contributes to breast tumour formation. There is evidence also for alterations in the ratio between the two PR isoforms in premalignant breast lesions. Elucidation of the factors mediating the effects of oestradiol and progesterone on development of the normal breast and of the mechanisms by which expression of the ERalpha and the PR isoforms is controlled could identify new targets for breast cancer prevention and improved prediction of breast cancer risk.
    • The role of p53 in spontaneous and radiation-induced apoptosis in the gastrointestinal tract of normal and p53-deficient mice.

      Merritt, Anita J; Potten, Christopher S; Kemp, C J; Hickman, John A; Balmain, A; Lane, D P; Hall, P A; CRC Department of Epithelial Biology, Paterson Institute for Cancer Research, Christie Hospital (NHS) Trust, Manchester, United Kingdom. (1994-02-01)
      Three h after whole-body irradiation (8 Gy) of C57BL x DBA/2 F1 mice, p53 protein was expressed strongly in the stem cell compartment of the small intestine but at lower levels in the colon. At this time, apoptotic cells were also observed in the stem cell position of the small intestine, with fewer in the colon. In mice without copies of the p53 gene (nulls), the levels of spontaneous apoptosis, in both the small intestine and the colon, were not different from wild-type. Irradiation of the nulls with 8 Gy of gamma-rays failed to induce any further apoptosis: the loss of p53 essentially rendered the epithelial cells, from both the small intestine and the colon, radioresistant. The response of the epithelial stem cells of the small intestine suggests that p53 may play a role in the deletion of damaged cells with carcinogenic potential, whereas this process is limited in the colon.
    • The role of p53 in suppression of KSHV cyclin-induced lymphomagenesis.

      Verschuren, Emmy W; Hodgson, J Graeme; Gray, Joe W; Kogan, Scott; Jones, Nic; Evan, Gerard I; Comprehensive Cancer Center and Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, USA. (2004-01-15)
      Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a cyclin D homolog, K cyclin, that is thought to promote viral oncogenesis. However, expression of K cyclin in cultured cells not only triggers cell cycle progression but also engages the p53 tumor suppressor pathway, which probably restricts the oncogenic potential of K cyclin. Therefore, to assess the tumorigenic properties of K cyclin in vivo, we transgenically targeted expression of K cyclin to the B and T lymphocyte compartments via the E micro promoter/enhancer. Around 17% of E micro -K cyclin animals develop lymphoma by 9 months of age, and all such lymphomas exhibit loss of p53. A critical role of p53 in suppressing K cyclin-induced lymphomagenesis was confirmed by the greatly accelerated onset of B and T lymphomagenesis in all E micro -K cyclin/p53(-/-) mice. However, absence of p53 did not appear to accelerate K cyclin-induced lymphomagenesis by averting apoptosis: E micro -K cyclin/p53(-/-) end-stage lymphomas contained abundant apoptotic cells, and transgenic E micro -K cyclin/p53(-/-) lymphocytes in vitro were not measurably protected from DNA damage-induced apoptosis compared with E micro -K cyclin/p53(wt) cells. Notably, whereas aneuploidy was frequently evident in pre-lymphomatous tissues, end-stage E micro -K cyclin/p53(-/-) tumors showed a near-diploid DNA content with no aberrant centrosome numbers. Nonetheless, such tumor cells did harbor more restricted genomic alterations, such as single-copy chromosome losses or gains or high-level amplifications. Together, our data support a model in which K cyclin-induced genome instability arises early in the pre-tumorigenic lymphocyte population and that loss of p53 licenses subsequent expansion of tumorigenic clones.
    • Role of phosphatidylinositol 5-phosphate 4-kinase α in zebrafish development.

      Elouarrat, D; van der Velden, Y; Jones, David R; Moolenaar, W; Divecha, Nullin; Haramis, A; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. (2013-07)
      Phosphatidylinositol 5-phosphate 4-kinases (PIP4Ks) phosphorylate phosphatidylinositol 5-phosphate (PI5P) to generate phosphatidylinositol 4,5-bisphosphate; their most likely function is the regulation of the levels of PI5P, a putative signalling intermediate. There are three mammalian PIP4Ks isoforms (α, β and γ), but their physiological roles remain poorly understood. In the present study, we identified the zebrafish orthologue (zPIP4Kα) of the high-activity human PIP4K α isoform and analyzed its role in embryonic development. RT-PCR analysis and whole-mount in situ hybridization experiments showed that zPIP4Kα is maternally expressed. At later embryonic stages, high PIP4Kα expression was detected in the head and the pectoral fins. Knockdown of zPIP4Kα by antisense morpholino oligonucleotides led to severe morphological abnormalities, including midbody winding defects at 48hpf. The abnormal phenotype could be rescued, at least in large part, by injection of human PIP4Kα mRNA. Our results reveal a key role for PIP4Kα and its activity in vertebrate tissue homeostasis and organ development.
    • Role of post-translational modifications in the acquisition of drug resistance in Mycobacterium tuberculosis

      Arora, G.; Bothra, A.; Prosser, Gareth; Arora, K.; Sajid, A.; Yale School of Medicine, Yale University, New Haven, CT, 06519, USA. (2020)
      Tuberculosis (TB) is one of the primary causes of deaths due to infectious diseases. The current TB regimen is long and complex, failing of which leads to relapse and/or the emergence of drug resistance. There is a critical need to understand the mechanisms of resistance development. With increasing drug pressure, Mycobacterium tuberculosis (Mtb) activates various pathways to counter drug-related toxicity. Signaling modules steer the evolution of Mtb to a variant that can survive, persist, adapt, and emerge as a form that is resistant to one or more drugs. Recent studies reveal that about 1/3rd of the annotated Mtb proteome is modified post-translationally, with a large number of these proteins being essential for mycobacterial survival. Post-translational modifications (PTMs) such as phosphorylation, acetylation, and pupylation play a salient role in mycobacterial virulence, pathogenesis, and metabolism. The role of many other PTMs is still emerging. Understanding the signaling pathways and PTMs may assist clinical strategies and drug development for Mtb. In this review, we explore the contribution of PTMs to mycobacterial physiology, describe the related cellular processes, and discuss how these processes are linked to drug resistance. A significant number of drug targets, InhA, RpoB, EmbR, and KatG, are modified at multiple residues via PTMs. A better understanding of drug-resistance regulons and associated PTMs will aid in developing effective drugs against TB.
    • Role of proteolytic enzymes in human prostate bone metastasis formation: in vivo and in vitro studies.

      Hart, Claire A; Scott, Linda J; Bagley, Steven; Bryden, A A G; Clarke, Noel W; Lang, Shona H; Cancer Research UK - Group of Experimental Haematology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Wilmslow Road, Manchester M20 4BX, UK. chart@picr.man.ac.uk (2002-04-08)
      Prostate cancers ability to invade and grow in bone marrow stroma is thought to be due in part to degradative enzymes. The formation of prostate skeletal metastases have been reproduced in vitro by growing co-cultures of prostatic epithelial cells in bone marrow stroma. Expression of urokinase plasminogen activator, matrix metalloproteinase 1 and 7 by prostatic epithelial cells were identified using immunocytochemistry. Also, in vivo tissue sections from human prostatic bone marrow metastases were stained. To establish the role of these enzymes on colony formation, inhibitory antibodies directed against urokinase plasminogen activator, matrix metalloproteinase 1 and matrix metalloproteinase 7 were added into primary prostatic epithelial cells and bone marrow stroma co-cultures. All prostatic epithelial cell cultures stained positively for matrix metalloproteinase 1, matrix metalloproteinase 7 and urokinase plasminogen activator. Generally prostatic epithelial cells derived from malignant tissues showed increased staining in comparison to epithelia derived from non-malignant tissue. In agreement with in vitro co-cultures, the in vivo tissue sections of prostate bone marrow metastases showed positive staining for all three enzymes. Inhibition studies demonstrated that blocking matrix metalloproteinase 1, matrix metalloproteinase 7 and urokinase plasminogen activator function reduced the median epithelial colony area significantly in bone marrow stroma co-cultures in vitro. Using a human ex-vivo model we have shown that matrix metalloproteinase 1, matrix metalloproteinase 7 and urokinase plasminogen activator play an important role in the establishment of prostatic epithelial cells within bone marrow.
    • Role of purified erythropoietin in the amplification of the erythroid compartment.

      Testa, Nydia G; Eliason, James; Frassoni, F; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester M20 9BX (1980)
      A single dose of Myleran induced a prolonged depletion of multi-potential haemopoietic cells and of early erythroid precursors to levels between 2 and 6 of control. In these mice, a priming dose of highly purified erythropoietin (Epo) or of any of 3 Epo preparations from different sources, and having different specific activities, increased the magnitude of the response to a test dose of Epo by erythropoietin responsive cells (ERC) in the hypertransfused mouse assay. As significant feeding into the ERC compartment from the most immature cells is unlikely because of the depletion induced by the Myleran, it may be concluded that highly purified Epo, not contaminated with other biologically active molecules, has a dual effect on the ERC: it causes increased amplification besides inducing differentiation into cells with the capacity to synthesize haemoglobin.