Objectives: The aim of this study was to investigate the anti-leukemic potential of coronopilin, a sesquiterpene lactone from Ambrosia arborescens, and characterize the mechanism(s) underlying its activity. Materials and methods: The study was conducted in Jurkat and U937, two leukemia-derived cell lines. Apoptosis and impairment of cell cycle progression were evaluated by flow cytometry and microscopic analysis. Changes in protein expression and activation were evaluated by western blot. Coronopilin-tubulin covalent adducts were demonstrated through mass spectrometry. Results: Coronopilin inhibited (IC50 ≤ 20 µM) the leukaemia cell growth, but displayed poor cytotoxicity in normal white blood cells. In Jurkat cells, coronopilin exerted cell growth inhibition activity mainly by triggering caspase-dependent apoptosis. Conversely, in U937 coronopilin primary response was a robust arrest in G2/M. The marked increase of the mitotic index and the presence of activated cyclinB1/Cdk1 complex, phosphorylated histone H3 at Ser10, and hyperpolymerized tubulin indicated that cells accumulated in mitosis. Prolonged mitotic arrest ultimately resulted in U937 mitotic catastrophe and dying cells exhibited the features of non caspase-dependent death. Conclusions: This study demonstrated that coronopilin efficiently inhibits leukemia cell growth by triggering cell type specific responses. Moreover, the coronopilin-mediated cell growth inhibition was specific for tumor cells since normal white blood cell viability was not significantly affected. Thus, coronopilin may represent an interesting new chemical scaffold to develop new antileukemic agents.
Effect of sesquiterpene lactone coronopilin on leukemia cell population growth, cell type-specific induction of apoptosis and mitotic catastrophe
BRACA, ALESSANDRA;
2012-01-01
Abstract
Objectives: The aim of this study was to investigate the anti-leukemic potential of coronopilin, a sesquiterpene lactone from Ambrosia arborescens, and characterize the mechanism(s) underlying its activity. Materials and methods: The study was conducted in Jurkat and U937, two leukemia-derived cell lines. Apoptosis and impairment of cell cycle progression were evaluated by flow cytometry and microscopic analysis. Changes in protein expression and activation were evaluated by western blot. Coronopilin-tubulin covalent adducts were demonstrated through mass spectrometry. Results: Coronopilin inhibited (IC50 ≤ 20 µM) the leukaemia cell growth, but displayed poor cytotoxicity in normal white blood cells. In Jurkat cells, coronopilin exerted cell growth inhibition activity mainly by triggering caspase-dependent apoptosis. Conversely, in U937 coronopilin primary response was a robust arrest in G2/M. The marked increase of the mitotic index and the presence of activated cyclinB1/Cdk1 complex, phosphorylated histone H3 at Ser10, and hyperpolymerized tubulin indicated that cells accumulated in mitosis. Prolonged mitotic arrest ultimately resulted in U937 mitotic catastrophe and dying cells exhibited the features of non caspase-dependent death. Conclusions: This study demonstrated that coronopilin efficiently inhibits leukemia cell growth by triggering cell type specific responses. Moreover, the coronopilin-mediated cell growth inhibition was specific for tumor cells since normal white blood cell viability was not significantly affected. Thus, coronopilin may represent an interesting new chemical scaffold to develop new antileukemic agents.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
