Related Experiment Videos
Chromatin structure and endonuclease sensitivity in human leukemic cell lines
N Kuribayashi1, H Sakagami, M Iida
1First Department of Biochemistry, School of Medicine, Showa University, Tokyo, Japan.
Anticancer Research
|May 1, 1996
Summary
Chromatin structure differences influence endonuclease sensitivity. Group I cancer cells show higher micrococcal nuclease sensitivity and internucleosomal DNA cleavage than Group II cells, suggesting distinct chromatin organization.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- Apoptosis involves DNA fragmentation, including internucleosomal cleavage.
- Chromatin structure plays a role in DNA accessibility and degradation during apoptosis.
Purpose of the Study:
- To investigate the relationship between chromatin structure and endonuclease sensitivity in different cancer cell lines.
- To determine if chromatin structure differences correlate with internucleosomal DNA cleavage during apoptosis.
Main Methods:
- Utilized human cancer cell lines (HL-60, ML-I, U-937, THP-I, MOLT-4, K562, T98G, U87MG, KG-1-C).
- Treated cells with apoptosis-inducing agents.
- Performed micrococcal nuclease and DNase I digestion on isolated nuclei.
- Analyzed histone fractions using acid-urea polyacrylamide gel electrophoresis.
Main Results:
- Group I cell lines (myelogenous leukemia) exhibited internucleosomal DNA cleavage and higher sensitivity to micrococcal nuclease compared to Group II cell lines.
- Group II cell lines (T-cell leukemia, erythroleukemia, glioblastoma, glioma) showed no internucleosomal DNA cleavage and lower micrococcal nuclease sensitivity.
- DNase I sensitivity was similar between both groups.
- Histone analysis revealed no selective degradation of histone H1, but rather non-specific degradation of nuclear proteins.
Conclusions:
- Differences in chromatin structure exist between Group I and Group II cell lines.
- These chromatin structure variations likely account for the selective internucleosomal DNA cleavage observed only in Group I cells during apoptosis.