Related Experiment Video
Updated: Aug 13, 2026

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
Published on: June 29, 2011
Acute changes in U937 nuclear Ca2+ preceding type 1 "apoptotic" programmed cell death due to MK 886
K M Anderson1, M Rubenstein, W A Alrefai
1Hektoen Institute, Department of Biochemistry, Rush University Medical Center, University of Illinois and West Side V.A. Chicago, IL 60612, USA. marander427@MSN.com
MK 886, a 5-lipoxygenase inhibitor, triggers programmed cell death by increasing reactive oxygen species and nuclear calcium in U937 cells. This mechanism, involving mitochondria and Bcl-2, differs in solid cancer cells.
Area of Science:
- Cell Biology
- Biochemistry
- Cancer Research
Background:
- MK 886, a 5-lipoxygenase inhibitor, induces type 1 programmed cell death (PCD) in Bcl-2-positive U937 cells.
- MK 886 treatment in Ca2+-depleted U937 cells leads to a rapid, acute increase in intracellular calcium.
Purpose of the Study:
- To investigate the mechanism of MK 886-induced programmed cell death.
- To elucidate the role of calcium and reactive oxygen species in MK 886-induced apoptosis.
Main Methods:
- Utilized fura-2 and spectrofluorimetry to detect intracellular calcium.
- Employed confocal microscopy to determine the subcellular localization of calcium increase.
- Assessed the involvement of mitochondria and reactive oxygen species using specific inhibitors and probes (e.g., N-acetyl-L-cysteine, antimycin A, rhodamine-2, 2',7'-dichloro-dihydrofluorescein).
Main Results:
- The acute calcium increase induced by MK 886 was primarily nuclear.
- Antioxidants, mitochondrial inhibitors, and calcium chelators reduced the MK 886-induced calcium rise.
- Reactive oxygen species increased from intracellular sites, including mitochondria, following MK 886 treatment.
- Inhibition of Bcl-2 function attenuated the calcium response to MK 886.
- Solid cancer cells (PC-3, panc-1) lacking Bcl-2 exhibited type 2 PCD without an acute nuclear calcium signal.
Conclusions:
- MK 886 induces reactive oxygen species from intracellular sources, leading to calcium release primarily near the nucleus.
- Bcl-2 may participate in calcium channel function, and reactive oxygen species may alter nuclear calcium-binding proteins.
- The distinct PCD pathways in Bcl-2-positive versus Bcl-2-negative cells, particularly regarding the nuclear calcium signal, require further investigation.
More Related Videos
09:18Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
Published on: December 27, 2016
04:20Knockdown of FAM83A to Verify Its Role in Cervical Cancer Cell Growth and Cisplatin Sensitivity
Published on: February 9, 2024
Related Concept Videos
Apoptosis
The Extrinsic Apoptotic Pathway
The Intrinsic Apoptotic Pathway
Necrosis
Morphological Manifestations of Necrosis
Necrotic cells show different types of morphological appearance depending on the type of tissue and infection. In coagulative necrosis, cells become anucleated and die, but their...
Cellular Injury IlI: Cellular Death
Cellular Injury V: Apoptosis and Autophagy