The use of Shiga-like toxin 1 in cancer therapy

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Abstract

The ribosome-inactivating protein, Shiga-like toxin-1 (SLT-1, SLT-I, Verotoxin 1, VT1) targets cells that express the glycolipid globotriaosylceramide (CD77) on their surface. The frequent occurrence of SLT-1 receptors on tumor cells derived from patients with hematological cancers (follicular lymphoma, multiple myeloma, chronic lymphocytic leukemia) and their absence on human CD34+ hematopoietic stem cells suggest the ex vivo use of Shiga-like toxin-1 in purging CD77+ tumor cells from autologous stem cell transplants. SLT-1 receptors are also commonly expressed on breast cancer, ovarian cancer and astrocytoma cells. In particular, the sensitivity of astrocytoma cell lines to this toxin provides an opportunity for using SLT-1 in vivo in the context of treating patients afflicted by this common form of brain tumor. Finally, the known structural features of SLT-1 allow one to contemplate altering its receptor specificity in an effort to target CD77- tumor cell populations.

Introduction

Ribosome-inactivating proteins such as ricin, abrin, Shiga and Shiga-like toxins represent examples of molecular templates optimized to target and kill eukaryotic cells. They exert their cytotoxic effect on cells by reaching the endoplasmic reticulum (ER) lumen and relocating their toxic domain to the cytosol. The toxicity and lack of selectivity of native toxins towards normal and cancer cells have limited their use as therapeutic agents. Instead, toxin domains have been coupled or fused to targeting agents such as antibodies and cytokines to create guided cytotoxic conjugates. The collective knowledge gathered in the past two decades on the structure and intracellular routing of Shiga toxin and Shiga-like toxin 1, as well as the nature and expression of its receptor on cells, has defined uses for Shiga-like toxin 1 in cancer therapy. This review highlights recent progress in using Shiga-like toxin 1 to target and destroy cancer cells.

Section snippets

Structure and function of Shiga-like toxin 1

Shiga-like toxin 1 (SLT-1, SLT-I, verotoxin I, VT-I) is a type-II ribosome-inactivating protein produced by pathogenic strains of Escherichia coli. Such strains of SLT-1 producing E. coli (VTEC) are responsible for worldwide outbreaks of hemorrhagic colitis (hamburger disease), hemolytic uremic syndrome (HUS) and thrombocytopenic purpura (TTP) [1], [2], [3]. SLT-1 is a member of a family of protein toxins termed AB5 which assemble into a characteristic quaternary structure composed of a single

Processing and intracellular routing of SLT-1

SLT-1 enters cells by binding to a surface glycolipid called globotriaosylceramide (Galα1-4Galβ1-4glucosylceramide or Gb3), also known as CD77 ([15], [16], [17], [18]; Fig. 2). Once bound, the toxin is internalized via clathrin-coated pits [19], and travels in a retrograde fashion through the Golgi apparatus and the endoplasmic reticulum ([20], [21]; Fig. 3). The importance of the retrograde transport step through the Golgi network was confirmed using Brefeldin A (BFA), an agent that disrupts

Shiga-like toxin 1 as a purging agent

Approximately 50% of patients with intermediate/high grade non-Hodgkin's lymphoma, and virtually all patients with low-grade non-Hodgkin's lymphoma, are not cured by conventional chemotherapy and radiotherapy [34]. High-dose chemotherapy (HDC) with autologous stem cell transplantation (ASCT) may represent the best treatment option for patients with acute leukemia in first remission or with intermediate-, high-grade non-Hodgkin's lymphoma in remission [35], [36], [37], [38]. This approach also

In vivo use of Shiga-like toxin 1

CD77 is a cell surface marker expressed on several non-hematopoietic cells such as human enterocytes and human kidney cells. This fact explains why Shiga toxin and SLT-1 represent important virulence factors in the pathogenesis of bacillary dysentery, E. coli infections responsible for hemorrhagic colitis, and hemolytic uremic syndrome. The use of SLT-1 in an in vivo therapeutic setting appears challenging at the present time. Topical application or the local deposition (intratumoral) of the

Future prospects

A purging protocol is presently being devised in preparation for a clinical trial involving patients with multiple myeloma slated to undergo high-dose chemotherapy with stem cell rescue. More importantly, SLT-1 represents an impressive cytotoxic template from which to derive more selective, tumor-targeted toxin variants for in vivo use. Mutant forms of the toxin with altered receptor specificity have now been generated against breast cancer cell lines insensitive to the action of the native

Acknowledgements

Supported by research grants from the Leukemia Society of America and the Terry Fox New Frontiers Initiative

Dr Jean Gariépy is a Professor of Medical Biophysics at the University of Toronto and a Senior Scientist at the Ontario Cancer Institute, Princess Margaret Hospital. He was originally trained as a peptide chemist and NMR spectroscopist in the Department of Biochemistry at the University of Alberta. His postdoctoral training at Stanford University introduced him to the field of bacterial toxins. His research interests have now moved to the areas of drug design, combinatorial chemistry, and

References (62)

  • J.C. Simpson et al.

    Ricin A chain utilises the endoplasmic reticulum-associated protein degradation pathway to enter the cytosol of yeast

    FEBS. letters

    (1999)
  • A.M. Gianni

    Where do we stand with respect to the use of peripheral blood progenitor cells?

    Ann. Oncol.

    (1994)
  • J.G. Gribben et al.

    Detection by polymerase chain reaction of residual cells with the bcl-2 translocation is associated with increased risk of relapse after autologous bone marrow transplantation for B-cell lymphoma

    Blood

    (1993)
  • J. Gordon et al.

    Phenotypes in chronic B-lymphocytic leukemia probed by monoclonal antibodies and immunoglobulin secretion studies: identification of stages of maturation arrest and the relation to clinical findings

    Blood

    (1983)
  • E.C. LaCasse et al.

    Shiga- like toxin purges human lymphoma from bone marrow of severe combined immunodeficient mice

    Blood

    (1996)
  • E.C. LaCasse et al.

    Shiga-like toxin 1 receptor on human breast carcinomas, lymphoma and myeloma and absence from CD 34+ human heamatopoietic cells: Implications for ex vivo tumor cell purging and autologous stem cell transplant

    Blood

    (1999)
  • A.J. Szczepek et al.

    A high frequency of circulating B cells share clonotypic IgH VDJ rearrangements with autologous bone marrow plasma cells in multiple myeloma as measured by single cell and in situ RT-PCR

    Blood

    (1998)
  • P. Lala et al.

    Retroviral transfection of Madin-Darby Canine Kidney cells with human MDR1 results in a major increase in globotriaosylceramide and 105 to 106-fold increased cell sensitivity to verocytotoxin. Role for p-glycoprotein in glycolipid synthesis

    J. Biol. Chem.

    (2000)
  • L.W. Riley

    The epidemiologic, clinical, and microbiologic features of hemorrhagic colitis

    Annu. Rev. Microbiol.

    (1987)
  • M.A. Karmali

    Infection by verocytotoxin-producing Escherichia coli

    Clin. Microbiol. Rev.

    (1989)
  • S. Askenazi

    Role of bacterial cytotoxins in hemolytic uremic syndrome and thrombotic thrombocytopenic purpura

    Annu. Rev. Med.

    (1993)
  • A.D. O'Brien et al.

    Shiga and Shiga-like toxins

    Microbiol. Rev.

    (1987)
  • M.E. Fraser et al.

    Crystal structure of the holotoxin from Shigella dysenteriae at 2.5 A resolution

    Nature Struct. Biol.

    (1994)
  • A.D. O'Brien et al.

    Shiga toxin: biochemistry, genetics, mode of action, and role in pathogenesis

    Curr. Top. Micro. Immunol.

    (1992)
  • Y. Endo et al.

    Site of action of a Vero toxin (VT2) from Escherichia coli 0157:H7 and of Shiga toxin on eukaryotic ribosomes

    Eur. J. Biochem.

    (1988)
  • C.J. Hovde et al.

    Evidence that glutamic acid 167 is an active-site residue of Shiga-like toxin I

    Proc. Natl. Acad. Sci. USA

    (1988)
  • R.L. Deresiewicz et al.

    Mutations affecting the activity of the Shiga-like toxin I A-chain

    Biochemistry

    (1992)
  • Y. Takeda

    Shiga and Shiga-like (Vero) toxins

  • M.H. Jacewicz et al.

    Pathogenesis of shigella diarrhea. XI. Isolation of a shigella toxin- binding glycolipid from rabbit jejunum and HeLa cells and its identification as globotriaosylceramide

    J. Exp. Med.

    (1986)
  • C.A. Lingwood

    Verotoxins and their glycolipid receptors

    Adv. Lipid. Res.

    (1993)
  • K. Sandvig et al.

    Endocytosis from coated pits of Shiga toxin: a glycolipid-binding protein from Shigella dysenteriae 1

    J. Cell. Biol.

    (1989)
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    Dr Jean Gariépy is a Professor of Medical Biophysics at the University of Toronto and a Senior Scientist at the Ontario Cancer Institute, Princess Margaret Hospital. He was originally trained as a peptide chemist and NMR spectroscopist in the Department of Biochemistry at the University of Alberta. His postdoctoral training at Stanford University introduced him to the field of bacterial toxins. His research interests have now moved to the areas of drug design, combinatorial chemistry, and peptide and protein engineering, with the general aim of developing targeted cancer therapies.

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