Korean J Clin Pathol.  2000 Oct;20(5):435-441.

Study of Hydroxyurea Induced Caspase Activities in Chronic Myelogenous Leukemic Cell Line, K562 cells

• Lee YJ
• Park RK
• So HS
• Park JS
• Cho JH
• Choi SI

Abstract

BACKGROUND: Chronic myelogenous leukemia is a chronic myeloproliferative disorder characterized by leukocytosis with myeloid elements at all stages of differentiation, t(9;22)(q34;q11) and bcr/abl rearrangement. We studied hydroxyurea induced apoptotic changes such as externalization of phosphatidylserine, caspase activities on human chronic myelogenous leukemic cell line, K562 cells.
METHODS
K562 cells were grown in RPMI 1640 supplemented with 10% fetal bovine serum and treated hydroxyurea. Viability was examined by MTT assay. Apoptosis were examined by annexin V stain, caspase (such as caspase-, caspase-, caspase-, caspase-, and caspase-) activities, and DNA fragmentation.
RESULTS
The viability of K562 cells were markedly decreased in a dose dependent manner of hydroxyurea. Phosphatidylserine externalization was detected by annexin V stain after 3 hours in hydroxyurea treated K562 cells and the value of lactate dehydrogenase was not significantly changed in their culture media. The upstream effector of caspase- was slightly increased and had influenced on caspase-. And downstream acting caspase protease of caspase- was markedly increased in a time dependent manner at hydroxyurea treated K562 cells. In addition, however the activities of caspase- and caspase- were not increased. We also found DNA fragmentation at hydroxyurea treated K562 cells between 48 hours and 72 hours on agarose gel electrophoresis.
CONCLUSIONS
Hydroxyurea induces apoptotic change in K562 cells via externalization of phosphatidylserine, activations of caspase-, caspase-, caspase- proteases, and DNA fragmentation.

Keyword

Hydroxyurea; K562 cells; Apoptosis; Caspase; Phosphatidylserine; DNA fragmentation

MeSH Terms

Annexin A5
Apoptosis
Cell Line*
Culture Media
DNA Fragmentation
Electrophoresis, Agar Gel
Humans
Hydroxyurea*
K562 Cells*
L-Lactate Dehydrogenase
Leukemia, Myelogenous, Chronic, BCR-ABL Positive
Leukocytosis
Myeloproliferative Disorders
Peptide Hydrolases
Annexin A5
Culture Media
Hydroxyurea
L-Lactate Dehydrogenase
Peptide Hydrolases