Absence of topoisomerase IIβ in an amsacrine-resistant human leukemia cell line with mutant topoisomerase IIα

Cynthia E. Herzog; Katherine A. Holmes; Laura M. Tuschong; Ram Ganapathi; Leonard A. Zwelling

Absence of topoisomerase IIβ in an amsacrine-resistant human leukemia cell line with mutant topoisomerase IIα

Cynthia E. Herzog, Katherine A. Holmes, Laura M. Tuschong, Ram Ganapathi, Leonard A. Zwelling

Research output: Contribution to journal › Article › peer-review

Abstract

Numerous chemotherapeutic agents act via stabilization of a topoisomerase (topo) II-DNA complex. HL-60/AMSA, a human leukemia cell line, is resistant to intercalator-mediated DNA complex formation and cytotoxicity. HL-60/AMSA contains a mutant form of topo IIα that was thought to explain this resistance. However, our present data show that expression of topo IIβ RNA in HL-60/AMSA is only 10% of that in HL-60, and topo IIβ protein levels are undetectable. Southern analysis of topo IIβ shows no differences in gene dosage between the two cell lines but does show differences in the restriction patterns. These data suggest that decreased topo IIβ expression may contribute to the intercalator resistance of HL-60/AMSA cells.

Original language	English (US)
Pages (from-to)	5298-5300
Number of pages	3
Journal	Cancer Research
Volume	58
Issue number	23
State	Published - Dec 1 1998

ASJC Scopus subject areas

Oncology
Cancer Research

Cite this

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title = "Absence of topoisomerase IIβ in an amsacrine-resistant human leukemia cell line with mutant topoisomerase IIα",

abstract = "Numerous chemotherapeutic agents act via stabilization of a topoisomerase (topo) II-DNA complex. HL-60/AMSA, a human leukemia cell line, is resistant to intercalator-mediated DNA complex formation and cytotoxicity. HL-60/AMSA contains a mutant form of topo IIα that was thought to explain this resistance. However, our present data show that expression of topo IIβ RNA in HL-60/AMSA is only 10% of that in HL-60, and topo IIβ protein levels are undetectable. Southern analysis of topo IIβ shows no differences in gene dosage between the two cell lines but does show differences in the restriction patterns. These data suggest that decreased topo IIβ expression may contribute to the intercalator resistance of HL-60/AMSA cells.",

author = "Herzog, {Cynthia E.} and Holmes, {Katherine A.} and Tuschong, {Laura M.} and Ram Ganapathi and Zwelling, {Leonard A.}",

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T1 - Absence of topoisomerase IIβ in an amsacrine-resistant human leukemia cell line with mutant topoisomerase IIα

AU - Herzog, Cynthia E.

AU - Holmes, Katherine A.

AU - Tuschong, Laura M.

AU - Ganapathi, Ram

AU - Zwelling, Leonard A.

PY - 1998/12/1

Y1 - 1998/12/1

N2 - Numerous chemotherapeutic agents act via stabilization of a topoisomerase (topo) II-DNA complex. HL-60/AMSA, a human leukemia cell line, is resistant to intercalator-mediated DNA complex formation and cytotoxicity. HL-60/AMSA contains a mutant form of topo IIα that was thought to explain this resistance. However, our present data show that expression of topo IIβ RNA in HL-60/AMSA is only 10% of that in HL-60, and topo IIβ protein levels are undetectable. Southern analysis of topo IIβ shows no differences in gene dosage between the two cell lines but does show differences in the restriction patterns. These data suggest that decreased topo IIβ expression may contribute to the intercalator resistance of HL-60/AMSA cells.

AB - Numerous chemotherapeutic agents act via stabilization of a topoisomerase (topo) II-DNA complex. HL-60/AMSA, a human leukemia cell line, is resistant to intercalator-mediated DNA complex formation and cytotoxicity. HL-60/AMSA contains a mutant form of topo IIα that was thought to explain this resistance. However, our present data show that expression of topo IIβ RNA in HL-60/AMSA is only 10% of that in HL-60, and topo IIβ protein levels are undetectable. Southern analysis of topo IIβ shows no differences in gene dosage between the two cell lines but does show differences in the restriction patterns. These data suggest that decreased topo IIβ expression may contribute to the intercalator resistance of HL-60/AMSA cells.

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Absence of topoisomerase IIβ in an amsacrine-resistant human leukemia cell line with mutant topoisomerase IIα

Abstract

ASJC Scopus subject areas

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