Overexpression of P-glycoprotein but not its mRNA in multidrug resistant cells selected with hydroxyrubicin

J. Y. Zhao, Niramol Savaraj, R. Song, W. Priebe, M. Tien Kuo

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Previous studies have revealed that cultured cells treated with lipophilic natural products containing aromatic rings and basic amino group usually yielded multidrug resistant (MDR) variants. These MDR cells overexpress P-glycoprotein (P-gp), most often due to gene amplification or transcriptional activation of mdr/P-gp genes. Doxorubicin (Dox) is an anthracycline that belongs to this group of compounds. To explore the possible resistance mechanism(s) to anthracyclines that do not involve P-gp, we use a Dox analog, hydroxyrubicin (HyR) or WP159, which contains a C3' hydroxy group in replacement of the amino group in the sugar moiety of Dox thereby reducing basicity and eliminating positive charge in the parental compound to establish HyR-resistant cell lines. These resistant cells displayed the MDR phenotype and overexpressed P-gp as analyzed by Western blot analyses and immunohistochemical staining using two different anti-P-gp antibodies. Strikingly, the levels of P-gp mRNA in the majority of these MDR cells remained comparable to those in the drug-sensitive counterparts by slot blot hybridization. These results implicate that the basic center of the selecting agent is a critical determinant for generating diverse MDR variants, and that HyR may have a posttranscriptional effect on P-gp biosynthesis. This is the first report suggesting that cultured cells exposed to a particular selecting agent may give rise to particular subtype of MDR variants.

Original languageEnglish
Pages (from-to)1735-1742
Number of pages8
JournalAnticancer Research
Volume14
Issue number5 A
StatePublished - Dec 1 1994
Externally publishedYes

Fingerprint

P-Glycoprotein
Messenger RNA
Doxorubicin
Anthracyclines
Transcriptional Activation
Cultured Cells
Gene Amplification
3'-deamino-3'-hydroxydoxorubicin
Biological Products
Western Blotting
Staining and Labeling
Phenotype
Cell Line
Antibodies
Pharmaceutical Preparations
Genes

Keywords

  • Doxorubicin
  • Gene expression
  • Hydroxyrubicin
  • Multidrug resistance
  • P-glycoprotein

ASJC Scopus subject areas

  • Cancer Research
  • Oncology

Cite this

Overexpression of P-glycoprotein but not its mRNA in multidrug resistant cells selected with hydroxyrubicin. / Zhao, J. Y.; Savaraj, Niramol; Song, R.; Priebe, W.; Tien Kuo, M.

In: Anticancer Research, Vol. 14, No. 5 A, 01.12.1994, p. 1735-1742.

Research output: Contribution to journalArticle

Zhao, J. Y. ; Savaraj, Niramol ; Song, R. ; Priebe, W. ; Tien Kuo, M. / Overexpression of P-glycoprotein but not its mRNA in multidrug resistant cells selected with hydroxyrubicin. In: Anticancer Research. 1994 ; Vol. 14, No. 5 A. pp. 1735-1742.
@article{81024912cc144447be002bc38809d76f,
title = "Overexpression of P-glycoprotein but not its mRNA in multidrug resistant cells selected with hydroxyrubicin",
abstract = "Previous studies have revealed that cultured cells treated with lipophilic natural products containing aromatic rings and basic amino group usually yielded multidrug resistant (MDR) variants. These MDR cells overexpress P-glycoprotein (P-gp), most often due to gene amplification or transcriptional activation of mdr/P-gp genes. Doxorubicin (Dox) is an anthracycline that belongs to this group of compounds. To explore the possible resistance mechanism(s) to anthracyclines that do not involve P-gp, we use a Dox analog, hydroxyrubicin (HyR) or WP159, which contains a C3' hydroxy group in replacement of the amino group in the sugar moiety of Dox thereby reducing basicity and eliminating positive charge in the parental compound to establish HyR-resistant cell lines. These resistant cells displayed the MDR phenotype and overexpressed P-gp as analyzed by Western blot analyses and immunohistochemical staining using two different anti-P-gp antibodies. Strikingly, the levels of P-gp mRNA in the majority of these MDR cells remained comparable to those in the drug-sensitive counterparts by slot blot hybridization. These results implicate that the basic center of the selecting agent is a critical determinant for generating diverse MDR variants, and that HyR may have a posttranscriptional effect on P-gp biosynthesis. This is the first report suggesting that cultured cells exposed to a particular selecting agent may give rise to particular subtype of MDR variants.",
keywords = "Doxorubicin, Gene expression, Hydroxyrubicin, Multidrug resistance, P-glycoprotein",
author = "Zhao, {J. Y.} and Niramol Savaraj and R. Song and W. Priebe and {Tien Kuo}, M.",
year = "1994",
month = "12",
day = "1",
language = "English",
volume = "14",
pages = "1735--1742",
journal = "Anticancer Research",
issn = "0250-7005",
publisher = "International Institute of Anticancer Research",
number = "5 A",

}

TY - JOUR

T1 - Overexpression of P-glycoprotein but not its mRNA in multidrug resistant cells selected with hydroxyrubicin

AU - Zhao, J. Y.

AU - Savaraj, Niramol

AU - Song, R.

AU - Priebe, W.

AU - Tien Kuo, M.

PY - 1994/12/1

Y1 - 1994/12/1

N2 - Previous studies have revealed that cultured cells treated with lipophilic natural products containing aromatic rings and basic amino group usually yielded multidrug resistant (MDR) variants. These MDR cells overexpress P-glycoprotein (P-gp), most often due to gene amplification or transcriptional activation of mdr/P-gp genes. Doxorubicin (Dox) is an anthracycline that belongs to this group of compounds. To explore the possible resistance mechanism(s) to anthracyclines that do not involve P-gp, we use a Dox analog, hydroxyrubicin (HyR) or WP159, which contains a C3' hydroxy group in replacement of the amino group in the sugar moiety of Dox thereby reducing basicity and eliminating positive charge in the parental compound to establish HyR-resistant cell lines. These resistant cells displayed the MDR phenotype and overexpressed P-gp as analyzed by Western blot analyses and immunohistochemical staining using two different anti-P-gp antibodies. Strikingly, the levels of P-gp mRNA in the majority of these MDR cells remained comparable to those in the drug-sensitive counterparts by slot blot hybridization. These results implicate that the basic center of the selecting agent is a critical determinant for generating diverse MDR variants, and that HyR may have a posttranscriptional effect on P-gp biosynthesis. This is the first report suggesting that cultured cells exposed to a particular selecting agent may give rise to particular subtype of MDR variants.

AB - Previous studies have revealed that cultured cells treated with lipophilic natural products containing aromatic rings and basic amino group usually yielded multidrug resistant (MDR) variants. These MDR cells overexpress P-glycoprotein (P-gp), most often due to gene amplification or transcriptional activation of mdr/P-gp genes. Doxorubicin (Dox) is an anthracycline that belongs to this group of compounds. To explore the possible resistance mechanism(s) to anthracyclines that do not involve P-gp, we use a Dox analog, hydroxyrubicin (HyR) or WP159, which contains a C3' hydroxy group in replacement of the amino group in the sugar moiety of Dox thereby reducing basicity and eliminating positive charge in the parental compound to establish HyR-resistant cell lines. These resistant cells displayed the MDR phenotype and overexpressed P-gp as analyzed by Western blot analyses and immunohistochemical staining using two different anti-P-gp antibodies. Strikingly, the levels of P-gp mRNA in the majority of these MDR cells remained comparable to those in the drug-sensitive counterparts by slot blot hybridization. These results implicate that the basic center of the selecting agent is a critical determinant for generating diverse MDR variants, and that HyR may have a posttranscriptional effect on P-gp biosynthesis. This is the first report suggesting that cultured cells exposed to a particular selecting agent may give rise to particular subtype of MDR variants.

KW - Doxorubicin

KW - Gene expression

KW - Hydroxyrubicin

KW - Multidrug resistance

KW - P-glycoprotein

UR - http://www.scopus.com/inward/record.url?scp=0028559947&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028559947&partnerID=8YFLogxK

M3 - Article

VL - 14

SP - 1735

EP - 1742

JO - Anticancer Research

JF - Anticancer Research

SN - 0250-7005

IS - 5 A

ER -