Related Experiment Video
Updated: Mar 17, 2026

Neutrophil Isolation and Analysis to Determine their Role in Lymphoma Cell Sensitivity to Therapeutic Agents
Published on: March 25, 2016
Nuclear Topoisomerase II Activity Changes During HL-60 Leukemic Cell Differentiation: Alterations in Drug Sensitivity
F Gieseler1, F Boege1, H Biersack1
1a Medizinische Poliklinik, University of Wuerzburg, D8700, Wuerzburg, Germany.
Abstract:
We have studied the effect of dimethyl-sulfoxide(DMSO)-induced granulocytic differentiation on the sensitivity of HL-60 cells to various cytotoxic topoisomerase II inhibitors: (i) undifferentiated HL-60 cells are highly sensitive to etoposide, while differentiated HL-60 cells are 700-1000 fold resistant to etoposide, (ii) undifferentiated HL-60 are 50-100 fold resistant against 4-(9-acridinylamino)methanesulfon-m-anisidide (mAMSA) when compared to the differentiated HL-60 cells, (iii) the addition of mAMSA to the medium inhibits granulocytic differentiation of HL-60 cells. This change in resistance pattern is probably due to an alteration of topoisomerases since distinctive iso-activites of topoisomerase can be discriminated on the basis of the pH profile, which alters markedly during differentiation. In an etoposide-resistant HL-60 cell line we found a reduced topoisomerase activity at pH 7.8/7.9. This topoisomerase iso-activity is obviously involved in etoposide cytotoxicity.
More Related Videos
06:33Author Spotlight: Comprehensive Epigenetic Analysis for Investigating Human Cellular Plasticity and Environmental Adaptation Using Immunofluorescence Assays
Published on: June 28, 2024
10:18From a 2DE-Gel Spot to Protein Function: Lesson Learned From HS1 in Chronic Lymphocytic Leukemia
Published on: October 19, 2014
Related Concept Videos
DNA Topoisomerases
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
The Nucleolus
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Differentiation of Common Myeloid Progenitor Cells
Histone Variants at the Centromere
Abnormal Proliferation