Alkylation and carbamylation effects of lomustine and its major metabolites and MGMT expression in canine cells

Thushara Chakkath, Sidonie Lavergne, Timothy M. Fan, David Bunick, Levent Dirikolu

Research output: Contribution to journalArticle

Abstract

DNA Alkylation is thought to be the reason for the efficacy of lomustine while carbamylation has been implicated as the cause for the side effects seen with lomustine treatment such as hepatotoxicity. In the alkylation study we show that lomustine and its metabolites form similar levels of the DNA adducts N 7 hydroxyethylguanine and O 6 hydroxyethyldeoxyguanosine. In terms of carbamylation, lomustine showed greater extent of carbamylation in the canine hepatocytes and lymphoma cell lines. The DNA repair enzyme O 6 methylguanine DNA methyltransferase (MGMT) causes resistance of tumor cells to bifunctional nitrosourea, like lomustine. There is no data available regarding MGMT expression/activity in canine cells or tissues. Our study shows that there is low MGMT activity in the canine lymphoid cell line 17-71 while the GL-1 cells did not show any detectable enzyme activity or mRNA expression. The MGMT enzyme activity measured in canine hepatocytes is about 250-350 fmol/mg protein as compared to about 90 fmol/mg protein in 17-71 cells. We also show that MGMT mRNA expression in 17-71 cells and canine hepatocytes positively correlates with its enzyme activity in these cells.

Original languageEnglish (US)
Pages (from-to)52-68
Number of pages17
JournalVeterinary Sciences
Volume2
Issue number2
DOIs
StatePublished - Jun 1 2015

Fingerprint

Lomustine
alkylation
methyltransferases
Methyltransferases
Alkylation
Canidae
metabolites
dogs
DNA
hepatocytes
Hepatocytes
cells
enzyme activity
O(6)-Methylguanine-DNA Methyltransferase
Enzymes
cell lines
DNA Repair Enzymes
DNA adducts
Cell Line
Messenger RNA

Keywords

  • Cis-4-hydroxylomustine
  • Lomustine
  • Lymphoma
  • MGMT
  • Trans-4-hydroxylomustine

ASJC Scopus subject areas

  • veterinary(all)

Cite this

Alkylation and carbamylation effects of lomustine and its major metabolites and MGMT expression in canine cells. / Chakkath, Thushara; Lavergne, Sidonie; Fan, Timothy M.; Bunick, David; Dirikolu, Levent.

In: Veterinary Sciences, Vol. 2, No. 2, 01.06.2015, p. 52-68.

Research output: Contribution to journalArticle

Chakkath, Thushara ; Lavergne, Sidonie ; Fan, Timothy M. ; Bunick, David ; Dirikolu, Levent. / Alkylation and carbamylation effects of lomustine and its major metabolites and MGMT expression in canine cells. In: Veterinary Sciences. 2015 ; Vol. 2, No. 2. pp. 52-68.
@article{fd3709025254440e9e8fad3113f9a651,
title = "Alkylation and carbamylation effects of lomustine and its major metabolites and MGMT expression in canine cells",
abstract = "DNA Alkylation is thought to be the reason for the efficacy of lomustine while carbamylation has been implicated as the cause for the side effects seen with lomustine treatment such as hepatotoxicity. In the alkylation study we show that lomustine and its metabolites form similar levels of the DNA adducts N 7 hydroxyethylguanine and O 6 hydroxyethyldeoxyguanosine. In terms of carbamylation, lomustine showed greater extent of carbamylation in the canine hepatocytes and lymphoma cell lines. The DNA repair enzyme O 6 methylguanine DNA methyltransferase (MGMT) causes resistance of tumor cells to bifunctional nitrosourea, like lomustine. There is no data available regarding MGMT expression/activity in canine cells or tissues. Our study shows that there is low MGMT activity in the canine lymphoid cell line 17-71 while the GL-1 cells did not show any detectable enzyme activity or mRNA expression. The MGMT enzyme activity measured in canine hepatocytes is about 250-350 fmol/mg protein as compared to about 90 fmol/mg protein in 17-71 cells. We also show that MGMT mRNA expression in 17-71 cells and canine hepatocytes positively correlates with its enzyme activity in these cells.",
keywords = "Cis-4-hydroxylomustine, Lomustine, Lymphoma, MGMT, Trans-4-hydroxylomustine",
author = "Thushara Chakkath and Sidonie Lavergne and Fan, {Timothy M.} and David Bunick and Levent Dirikolu",
year = "2015",
month = "6",
day = "1",
doi = "10.3390/vetsci2020052",
language = "English (US)",
volume = "2",
pages = "52--68",
journal = "Veterinary Sciences",
issn = "2306-7381",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "2",

}

TY - JOUR

T1 - Alkylation and carbamylation effects of lomustine and its major metabolites and MGMT expression in canine cells

AU - Chakkath, Thushara

AU - Lavergne, Sidonie

AU - Fan, Timothy M.

AU - Bunick, David

AU - Dirikolu, Levent

PY - 2015/6/1

Y1 - 2015/6/1

N2 - DNA Alkylation is thought to be the reason for the efficacy of lomustine while carbamylation has been implicated as the cause for the side effects seen with lomustine treatment such as hepatotoxicity. In the alkylation study we show that lomustine and its metabolites form similar levels of the DNA adducts N 7 hydroxyethylguanine and O 6 hydroxyethyldeoxyguanosine. In terms of carbamylation, lomustine showed greater extent of carbamylation in the canine hepatocytes and lymphoma cell lines. The DNA repair enzyme O 6 methylguanine DNA methyltransferase (MGMT) causes resistance of tumor cells to bifunctional nitrosourea, like lomustine. There is no data available regarding MGMT expression/activity in canine cells or tissues. Our study shows that there is low MGMT activity in the canine lymphoid cell line 17-71 while the GL-1 cells did not show any detectable enzyme activity or mRNA expression. The MGMT enzyme activity measured in canine hepatocytes is about 250-350 fmol/mg protein as compared to about 90 fmol/mg protein in 17-71 cells. We also show that MGMT mRNA expression in 17-71 cells and canine hepatocytes positively correlates with its enzyme activity in these cells.

AB - DNA Alkylation is thought to be the reason for the efficacy of lomustine while carbamylation has been implicated as the cause for the side effects seen with lomustine treatment such as hepatotoxicity. In the alkylation study we show that lomustine and its metabolites form similar levels of the DNA adducts N 7 hydroxyethylguanine and O 6 hydroxyethyldeoxyguanosine. In terms of carbamylation, lomustine showed greater extent of carbamylation in the canine hepatocytes and lymphoma cell lines. The DNA repair enzyme O 6 methylguanine DNA methyltransferase (MGMT) causes resistance of tumor cells to bifunctional nitrosourea, like lomustine. There is no data available regarding MGMT expression/activity in canine cells or tissues. Our study shows that there is low MGMT activity in the canine lymphoid cell line 17-71 while the GL-1 cells did not show any detectable enzyme activity or mRNA expression. The MGMT enzyme activity measured in canine hepatocytes is about 250-350 fmol/mg protein as compared to about 90 fmol/mg protein in 17-71 cells. We also show that MGMT mRNA expression in 17-71 cells and canine hepatocytes positively correlates with its enzyme activity in these cells.

KW - Cis-4-hydroxylomustine

KW - Lomustine

KW - Lymphoma

KW - MGMT

KW - Trans-4-hydroxylomustine

UR - http://www.scopus.com/inward/record.url?scp=85045438195&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85045438195&partnerID=8YFLogxK

U2 - 10.3390/vetsci2020052

DO - 10.3390/vetsci2020052

M3 - Article

AN - SCOPUS:85045438195

VL - 2

SP - 52

EP - 68

JO - Veterinary Sciences

JF - Veterinary Sciences

SN - 2306-7381

IS - 2

ER -