Polyglutamylation, an important element in methotrexate cytotoxicity and selectivity in tumor versus murine granulocytic progenitor cells in vitro

I. Fabre, G. Fabre, I. David Goldman

Research output: Contribution to journalArticle

83 Citations (Scopus)

Abstract

Methotrexate (MTX) cytotoxicity was assessed by clonogenic assay in agar with granulocytic progenitor cells from mouse bone marrow and in the Ehrlich ascites tumor, the K562 human chronic myelogenous leukemia, and the P388 murine leukemia. After a 2-hr exposure to MTX, the concentrations necessary to produce 50% inhibition of colony formation were 100, 25, 1.2, and 0.25 μM, respectively. This was inversely related to the ability of the tumor cells to accumulate MTX polyglutamyl derivatives and consistent with the observation that no polyglutamyl derivatives were observed in granulocytic progenitor cells after a 2-hr exposure to 5 μM MTX. Continuous exposure to glycine (200 μM)-adenosine (100 μM)-thymidine (10 μM) (GAT), along with MTX, protected cells from MTX cytotoxicity by circumventing the requirement for tetrahydrofolate cofactors. However, while the presence of GAT during a 2-hr exposure to 5 μM MTX is sufficient to protect granulocyte progenitor cells from MTX cytotoxicity, the presence of GAT, even after MTX is removed, is required to protect tumor cells. Indeed, if, after a 2-hr exposure of tumor cells to MTX and GAT, both MTX and GAT are removed before plating in agar, cytotoxicity to tumor cells was expressed. This sustained antitumor effect of MTX correlates with the rapid build-up of polyglutamyl derivatives that are retained in the cell even after extracellular and intracellular monoglutamate is eliminated. This is in contrast to granulocytic progenitor cells which appear to be susceptible to the drug only during the period of exposure to the monoglutamate under these conditions. The data strongly suggest that the marked differences in the accumulation of MTX polyglutamyl derivatives between the tumor cells studied and the murine bone marrow granulocytic progenitor cells are an important element in MTX selectivity.

Original languageEnglish (US)
Pages (from-to)3190-3195
Number of pages6
JournalCancer Research
Volume44
Issue number8
StatePublished - 1984
Externally publishedYes

Fingerprint

Methotrexate
Stem Cells
Neoplasms
In Vitro Techniques
Agar
Bone Marrow
Leukemia P388
Ehrlich Tumor Carcinoma
Granulocyte Precursor Cells
Leukemia, Myelogenous, Chronic, BCR-ABL Positive
Adenosine
Glycine
Thymidine
Leukemia
GAT

ASJC Scopus subject areas

  • Cancer Research
  • Oncology

Cite this

@article{8c2fb80232d44699b6e52f9388a9e9d9,
title = "Polyglutamylation, an important element in methotrexate cytotoxicity and selectivity in tumor versus murine granulocytic progenitor cells in vitro",
abstract = "Methotrexate (MTX) cytotoxicity was assessed by clonogenic assay in agar with granulocytic progenitor cells from mouse bone marrow and in the Ehrlich ascites tumor, the K562 human chronic myelogenous leukemia, and the P388 murine leukemia. After a 2-hr exposure to MTX, the concentrations necessary to produce 50{\%} inhibition of colony formation were 100, 25, 1.2, and 0.25 μM, respectively. This was inversely related to the ability of the tumor cells to accumulate MTX polyglutamyl derivatives and consistent with the observation that no polyglutamyl derivatives were observed in granulocytic progenitor cells after a 2-hr exposure to 5 μM MTX. Continuous exposure to glycine (200 μM)-adenosine (100 μM)-thymidine (10 μM) (GAT), along with MTX, protected cells from MTX cytotoxicity by circumventing the requirement for tetrahydrofolate cofactors. However, while the presence of GAT during a 2-hr exposure to 5 μM MTX is sufficient to protect granulocyte progenitor cells from MTX cytotoxicity, the presence of GAT, even after MTX is removed, is required to protect tumor cells. Indeed, if, after a 2-hr exposure of tumor cells to MTX and GAT, both MTX and GAT are removed before plating in agar, cytotoxicity to tumor cells was expressed. This sustained antitumor effect of MTX correlates with the rapid build-up of polyglutamyl derivatives that are retained in the cell even after extracellular and intracellular monoglutamate is eliminated. This is in contrast to granulocytic progenitor cells which appear to be susceptible to the drug only during the period of exposure to the monoglutamate under these conditions. The data strongly suggest that the marked differences in the accumulation of MTX polyglutamyl derivatives between the tumor cells studied and the murine bone marrow granulocytic progenitor cells are an important element in MTX selectivity.",
author = "I. Fabre and G. Fabre and Goldman, {I. David}",
year = "1984",
language = "English (US)",
volume = "44",
pages = "3190--3195",
journal = "Cancer Research",
issn = "0008-5472",
publisher = "American Association for Cancer Research Inc.",
number = "8",

}

TY - JOUR

T1 - Polyglutamylation, an important element in methotrexate cytotoxicity and selectivity in tumor versus murine granulocytic progenitor cells in vitro

AU - Fabre, I.

AU - Fabre, G.

AU - Goldman, I. David

PY - 1984

Y1 - 1984

N2 - Methotrexate (MTX) cytotoxicity was assessed by clonogenic assay in agar with granulocytic progenitor cells from mouse bone marrow and in the Ehrlich ascites tumor, the K562 human chronic myelogenous leukemia, and the P388 murine leukemia. After a 2-hr exposure to MTX, the concentrations necessary to produce 50% inhibition of colony formation were 100, 25, 1.2, and 0.25 μM, respectively. This was inversely related to the ability of the tumor cells to accumulate MTX polyglutamyl derivatives and consistent with the observation that no polyglutamyl derivatives were observed in granulocytic progenitor cells after a 2-hr exposure to 5 μM MTX. Continuous exposure to glycine (200 μM)-adenosine (100 μM)-thymidine (10 μM) (GAT), along with MTX, protected cells from MTX cytotoxicity by circumventing the requirement for tetrahydrofolate cofactors. However, while the presence of GAT during a 2-hr exposure to 5 μM MTX is sufficient to protect granulocyte progenitor cells from MTX cytotoxicity, the presence of GAT, even after MTX is removed, is required to protect tumor cells. Indeed, if, after a 2-hr exposure of tumor cells to MTX and GAT, both MTX and GAT are removed before plating in agar, cytotoxicity to tumor cells was expressed. This sustained antitumor effect of MTX correlates with the rapid build-up of polyglutamyl derivatives that are retained in the cell even after extracellular and intracellular monoglutamate is eliminated. This is in contrast to granulocytic progenitor cells which appear to be susceptible to the drug only during the period of exposure to the monoglutamate under these conditions. The data strongly suggest that the marked differences in the accumulation of MTX polyglutamyl derivatives between the tumor cells studied and the murine bone marrow granulocytic progenitor cells are an important element in MTX selectivity.

AB - Methotrexate (MTX) cytotoxicity was assessed by clonogenic assay in agar with granulocytic progenitor cells from mouse bone marrow and in the Ehrlich ascites tumor, the K562 human chronic myelogenous leukemia, and the P388 murine leukemia. After a 2-hr exposure to MTX, the concentrations necessary to produce 50% inhibition of colony formation were 100, 25, 1.2, and 0.25 μM, respectively. This was inversely related to the ability of the tumor cells to accumulate MTX polyglutamyl derivatives and consistent with the observation that no polyglutamyl derivatives were observed in granulocytic progenitor cells after a 2-hr exposure to 5 μM MTX. Continuous exposure to glycine (200 μM)-adenosine (100 μM)-thymidine (10 μM) (GAT), along with MTX, protected cells from MTX cytotoxicity by circumventing the requirement for tetrahydrofolate cofactors. However, while the presence of GAT during a 2-hr exposure to 5 μM MTX is sufficient to protect granulocyte progenitor cells from MTX cytotoxicity, the presence of GAT, even after MTX is removed, is required to protect tumor cells. Indeed, if, after a 2-hr exposure of tumor cells to MTX and GAT, both MTX and GAT are removed before plating in agar, cytotoxicity to tumor cells was expressed. This sustained antitumor effect of MTX correlates with the rapid build-up of polyglutamyl derivatives that are retained in the cell even after extracellular and intracellular monoglutamate is eliminated. This is in contrast to granulocytic progenitor cells which appear to be susceptible to the drug only during the period of exposure to the monoglutamate under these conditions. The data strongly suggest that the marked differences in the accumulation of MTX polyglutamyl derivatives between the tumor cells studied and the murine bone marrow granulocytic progenitor cells are an important element in MTX selectivity.

UR - http://www.scopus.com/inward/record.url?scp=0021167732&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021167732&partnerID=8YFLogxK

M3 - Article

VL - 44

SP - 3190

EP - 3195

JO - Cancer Research

JF - Cancer Research

SN - 0008-5472

IS - 8

ER -