Reduced activity of topoisomerase II in an Adriamycin-resistant human stomach-adenocarcinoma cell line

Young Sook Son, Jae Myoung Suh, Soo Hyun Ahn, Jun Chul Kim, Jae Youn Yi, Kyu Chung Hur, Weon Seon Hong, Mark T. Muller, In Kwon Chung

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

A human stomach-adenocarcinoma cell line (MKN-45) was selected for resistance to Adriamycin by stepwise exposure to increasing concentrations of this agent. The resulting cell line (MKN/ADR) exhibited a high level of cross-resistance to topoisomerase II (topo II)-targeted drugs such as Adriamycin, mitoxantrone, and etoposide but showed no cross-resistance to other chemotherapeutic agents such as cisplatin, carboplatin, 5-fluorouracil, or mitomycin-C. P-glycoprotein encoded by the mdr-1 gene was not overexpressed in the MKN/ADR cell line. The doubling time of the MKN/ADR cell line (2.1 days) increased only slightly as compared with that of the MKN cell line (1.7 days). The patterns of cross-resistance to various chemotherapeutic agents led us to examine the cellular contents of topo II in both the drug-sensitive and the drug-resistant cells. Extractable topo II enzyme activity was 3-fold lower in MKN/ADR cells as compared with the parental MKN cells. Levels of topoisomerase I (topo I) catalytic activity were similar in both wild-type MKN and drug-resistant MKN/ADR cells. Southern-blot analysis of genomic DNA probed with topo IIα or IIβ showed no sign of either gene rearrangement or hypermethylation. Northern-blot analysis revealed that both topo IIα and topo IIβ mRNA transcripts were essentially identical in the MKN and MKN/ADR cells. In contrast, Western-blot analysis revealed an approximately 20-fold lower level of topo IIα in drug-resistant cells as compared with drug-sensitive cells, whereas topo IIβ levels were similar in both lines. Moreover, the amount of in vivo topo IIα-DNA covalent complexes formed in the presence of etoposide was also approximately 20-fold lower in drug-resistant cells. No mutation was detected in the promoter region of the topo IIα gene in resistant cells as compared with sensitive cells. Thus, low levels of topo IIα polypeptide cannot be ascribed to changes in the mRNA levels. Collectively, the data suggest that a quantitative reduction in topo IIα may contribute to the resistance of MKN cells to Adriamycin and other topo II-targeted drugs.

Original languageEnglish
Pages (from-to)353-360
Number of pages8
JournalCancer Chemotherapy and Pharmacology
Volume41
Issue number5
DOIs
Publication statusPublished - 1998 Mar 13

Fingerprint

Type II DNA Topoisomerase
Doxorubicin
Stomach
Adenocarcinoma
Cells
Cell Line
Pharmaceutical Preparations
Genes
Etoposide
Mitoxantrone
Type I DNA Topoisomerase
Messenger RNA
Gene Rearrangement
Carboplatin
Enzyme activity
P-Glycoprotein
Mitomycin
Southern Blotting
Genetic Promoter Regions
Fluorouracil

All Science Journal Classification (ASJC) codes

  • Oncology
  • Toxicology
  • Pharmacology
  • Cancer Research
  • Pharmacology (medical)

Cite this

Son, Young Sook ; Suh, Jae Myoung ; Ahn, Soo Hyun ; Kim, Jun Chul ; Yi, Jae Youn ; Hur, Kyu Chung ; Hong, Weon Seon ; Muller, Mark T. ; Chung, In Kwon. / Reduced activity of topoisomerase II in an Adriamycin-resistant human stomach-adenocarcinoma cell line. In: Cancer Chemotherapy and Pharmacology. 1998 ; Vol. 41, No. 5. pp. 353-360.
@article{8735f8215e0e47de8426420b9c381662,
title = "Reduced activity of topoisomerase II in an Adriamycin-resistant human stomach-adenocarcinoma cell line",
abstract = "A human stomach-adenocarcinoma cell line (MKN-45) was selected for resistance to Adriamycin by stepwise exposure to increasing concentrations of this agent. The resulting cell line (MKN/ADR) exhibited a high level of cross-resistance to topoisomerase II (topo II)-targeted drugs such as Adriamycin, mitoxantrone, and etoposide but showed no cross-resistance to other chemotherapeutic agents such as cisplatin, carboplatin, 5-fluorouracil, or mitomycin-C. P-glycoprotein encoded by the mdr-1 gene was not overexpressed in the MKN/ADR cell line. The doubling time of the MKN/ADR cell line (2.1 days) increased only slightly as compared with that of the MKN cell line (1.7 days). The patterns of cross-resistance to various chemotherapeutic agents led us to examine the cellular contents of topo II in both the drug-sensitive and the drug-resistant cells. Extractable topo II enzyme activity was 3-fold lower in MKN/ADR cells as compared with the parental MKN cells. Levels of topoisomerase I (topo I) catalytic activity were similar in both wild-type MKN and drug-resistant MKN/ADR cells. Southern-blot analysis of genomic DNA probed with topo IIα or IIβ showed no sign of either gene rearrangement or hypermethylation. Northern-blot analysis revealed that both topo IIα and topo IIβ mRNA transcripts were essentially identical in the MKN and MKN/ADR cells. In contrast, Western-blot analysis revealed an approximately 20-fold lower level of topo IIα in drug-resistant cells as compared with drug-sensitive cells, whereas topo IIβ levels were similar in both lines. Moreover, the amount of in vivo topo IIα-DNA covalent complexes formed in the presence of etoposide was also approximately 20-fold lower in drug-resistant cells. No mutation was detected in the promoter region of the topo IIα gene in resistant cells as compared with sensitive cells. Thus, low levels of topo IIα polypeptide cannot be ascribed to changes in the mRNA levels. Collectively, the data suggest that a quantitative reduction in topo IIα may contribute to the resistance of MKN cells to Adriamycin and other topo II-targeted drugs.",
author = "Son, {Young Sook} and Suh, {Jae Myoung} and Ahn, {Soo Hyun} and Kim, {Jun Chul} and Yi, {Jae Youn} and Hur, {Kyu Chung} and Hong, {Weon Seon} and Muller, {Mark T.} and Chung, {In Kwon}",
year = "1998",
month = "3",
day = "13",
doi = "10.1007/s002800050751",
language = "English",
volume = "41",
pages = "353--360",
journal = "Cancer Chemotherapy and Pharmacology",
issn = "0344-5704",
publisher = "Springer Verlag",
number = "5",

}

Reduced activity of topoisomerase II in an Adriamycin-resistant human stomach-adenocarcinoma cell line. / Son, Young Sook; Suh, Jae Myoung; Ahn, Soo Hyun; Kim, Jun Chul; Yi, Jae Youn; Hur, Kyu Chung; Hong, Weon Seon; Muller, Mark T.; Chung, In Kwon.

In: Cancer Chemotherapy and Pharmacology, Vol. 41, No. 5, 13.03.1998, p. 353-360.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Reduced activity of topoisomerase II in an Adriamycin-resistant human stomach-adenocarcinoma cell line

AU - Son, Young Sook

AU - Suh, Jae Myoung

AU - Ahn, Soo Hyun

AU - Kim, Jun Chul

AU - Yi, Jae Youn

AU - Hur, Kyu Chung

AU - Hong, Weon Seon

AU - Muller, Mark T.

AU - Chung, In Kwon

PY - 1998/3/13

Y1 - 1998/3/13

N2 - A human stomach-adenocarcinoma cell line (MKN-45) was selected for resistance to Adriamycin by stepwise exposure to increasing concentrations of this agent. The resulting cell line (MKN/ADR) exhibited a high level of cross-resistance to topoisomerase II (topo II)-targeted drugs such as Adriamycin, mitoxantrone, and etoposide but showed no cross-resistance to other chemotherapeutic agents such as cisplatin, carboplatin, 5-fluorouracil, or mitomycin-C. P-glycoprotein encoded by the mdr-1 gene was not overexpressed in the MKN/ADR cell line. The doubling time of the MKN/ADR cell line (2.1 days) increased only slightly as compared with that of the MKN cell line (1.7 days). The patterns of cross-resistance to various chemotherapeutic agents led us to examine the cellular contents of topo II in both the drug-sensitive and the drug-resistant cells. Extractable topo II enzyme activity was 3-fold lower in MKN/ADR cells as compared with the parental MKN cells. Levels of topoisomerase I (topo I) catalytic activity were similar in both wild-type MKN and drug-resistant MKN/ADR cells. Southern-blot analysis of genomic DNA probed with topo IIα or IIβ showed no sign of either gene rearrangement or hypermethylation. Northern-blot analysis revealed that both topo IIα and topo IIβ mRNA transcripts were essentially identical in the MKN and MKN/ADR cells. In contrast, Western-blot analysis revealed an approximately 20-fold lower level of topo IIα in drug-resistant cells as compared with drug-sensitive cells, whereas topo IIβ levels were similar in both lines. Moreover, the amount of in vivo topo IIα-DNA covalent complexes formed in the presence of etoposide was also approximately 20-fold lower in drug-resistant cells. No mutation was detected in the promoter region of the topo IIα gene in resistant cells as compared with sensitive cells. Thus, low levels of topo IIα polypeptide cannot be ascribed to changes in the mRNA levels. Collectively, the data suggest that a quantitative reduction in topo IIα may contribute to the resistance of MKN cells to Adriamycin and other topo II-targeted drugs.

AB - A human stomach-adenocarcinoma cell line (MKN-45) was selected for resistance to Adriamycin by stepwise exposure to increasing concentrations of this agent. The resulting cell line (MKN/ADR) exhibited a high level of cross-resistance to topoisomerase II (topo II)-targeted drugs such as Adriamycin, mitoxantrone, and etoposide but showed no cross-resistance to other chemotherapeutic agents such as cisplatin, carboplatin, 5-fluorouracil, or mitomycin-C. P-glycoprotein encoded by the mdr-1 gene was not overexpressed in the MKN/ADR cell line. The doubling time of the MKN/ADR cell line (2.1 days) increased only slightly as compared with that of the MKN cell line (1.7 days). The patterns of cross-resistance to various chemotherapeutic agents led us to examine the cellular contents of topo II in both the drug-sensitive and the drug-resistant cells. Extractable topo II enzyme activity was 3-fold lower in MKN/ADR cells as compared with the parental MKN cells. Levels of topoisomerase I (topo I) catalytic activity were similar in both wild-type MKN and drug-resistant MKN/ADR cells. Southern-blot analysis of genomic DNA probed with topo IIα or IIβ showed no sign of either gene rearrangement or hypermethylation. Northern-blot analysis revealed that both topo IIα and topo IIβ mRNA transcripts were essentially identical in the MKN and MKN/ADR cells. In contrast, Western-blot analysis revealed an approximately 20-fold lower level of topo IIα in drug-resistant cells as compared with drug-sensitive cells, whereas topo IIβ levels were similar in both lines. Moreover, the amount of in vivo topo IIα-DNA covalent complexes formed in the presence of etoposide was also approximately 20-fold lower in drug-resistant cells. No mutation was detected in the promoter region of the topo IIα gene in resistant cells as compared with sensitive cells. Thus, low levels of topo IIα polypeptide cannot be ascribed to changes in the mRNA levels. Collectively, the data suggest that a quantitative reduction in topo IIα may contribute to the resistance of MKN cells to Adriamycin and other topo II-targeted drugs.

UR - http://www.scopus.com/inward/record.url?scp=0031905844&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031905844&partnerID=8YFLogxK

U2 - 10.1007/s002800050751

DO - 10.1007/s002800050751

M3 - Article

VL - 41

SP - 353

EP - 360

JO - Cancer Chemotherapy and Pharmacology

JF - Cancer Chemotherapy and Pharmacology

SN - 0344-5704

IS - 5

ER -