Open Access

U937 variant cells as a model of apoptosis without cell disintegration

  • Grzegorz Stasiłojć187,
  • Sandra Pinto387,
  • Roksana Wyszkowska187,
  • Magda Wejda187, 487,
  • Ewa M. Słomińska287,
  • Martyna Filipska187,
  • Patrycja Koszałka187,
  • Julian Świerczyński287,
  • Jose Enrique O’Connor387 and
  • Jacek Jerzy Bigda187, 587Email author
Cellular & Molecular Biology LettersAn International Journal201318:87

https://doi.org/10.2478/s11658-013-0087-y

Received: 15 November 2012

Accepted: 13 April 2013

Published: 20 April 2013

Abstract

The variant cell line U937V was originally identified by a higher sensitivity to the cytocidal action of tumor necrosis factor alpha (TNFα) than that of its reference cell line, U937. We noticed that a typical morphological feature of dying U937V cells was the lack of cellular disintegration, which contrasts to the formation of apoptotic bodies seen with dying U937 cells. We found that both TNFα, which induces the extrinsic apoptotic pathway, and etoposide (VP-16), which induces the intrinsic apoptotic pathway, stimulated U937V cell death without cell disintegration. In spite of the distinct morphological differences between the U937 and U937V cells, the basic molecular events of apoptosis, such as internucleosomal DNA degradation, phosphatidylserine exposure on the outer leaflet of the plasma membrane, caspase activation and cytochrome c release, were evident in both cell types when stimulated with both types of apoptosis inducer. In the U937V cells, we noted an accelerated release of cytochrome c, an accelerated decrease in mitochondrial membrane potential, and a more pronounced generation of reactive oxygen species compared to the reference cells. We propose that the U937 and U937V cell lines could serve as excellent comparison models for studies on the mechanisms regulating the processes of cellular disintegration during apoptosis, such as blebbing (zeiosis) and apoptotic body formation.

Key words

Apoptosis U937 cells Apoptotic bodies Cell disintegration

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