Viscum album agglutinin-I induces degradation of cytoskeletal proteins in leukaemia PLB-985 cells differentiated toward neutrophils: cleavage of non-muscle myosin heavy chain-IIA by caspases

Br J Haematol. 2007 Aug;138(4):545-54. doi: 10.1111/j.1365-2141.2007.06692.x.

Abstract

The role of the anti-cancer agent Viscum album agglutinin-I (VAA-I) in leukaemia PLB-985 cells differentiated toward a neutrophil-like phenotype by dimethylsulphoxide (PLB-985D) has never been studied. This study investigated whether or not VAA-I can induce cytoskeletal breakdown in PLB-985D cells, as previously observed in undifferentiated PLB-985 cells. VAA-I was found to induce apoptosis in PLB-985D cells, as assessed by cytology and by degradation of gelsolin, an event known to occur via caspase-3 activation. VAA-I induced cytoskeletal breakdown based on the disruption of the F-actin network and cleavage of paxillin, vimentin and lamin B(1). In addition, we demonstrated, for the first time, that non-muscle myosin heavy chain IIA (NMHC-IIA) was cleaved by VAA-I treatment. Degradation of NMHC-IIA was reversed by the pan caspase inhibitor z-VAD-fmk in PLB-985D cells and neutrophils. However, unlike lamin B(1), no NMHC-IIA was detected on the cell surface of apoptotic neutrophils. In conclusion, PLB-985D cells responded in a similar manner to neutrophils regarding the degradation of the tested cytoskeletal. Therefore, PLB-985D cells may provide a suitable substitute for neutrophils in screening experiments, preventing extensive neutrophil cell isolation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / therapeutic use*
  • Apoptosis / drug effects
  • Caspases / genetics
  • Caspases / metabolism*
  • Cell Differentiation
  • Cell Line, Tumor
  • Cytoskeleton / drug effects
  • Cytoskeleton / metabolism
  • Flow Cytometry
  • Humans
  • Lamin Type B / analysis
  • Lamin Type B / metabolism
  • Leukemia / drug therapy*
  • Leukemia / metabolism
  • Neutrophils / immunology*
  • Nonmuscle Myosin Type IIA / analysis
  • Nonmuscle Myosin Type IIA / metabolism*
  • Paxillin / analysis
  • Paxillin / metabolism
  • Plant Preparations / therapeutic use*
  • Plant Proteins / therapeutic use*
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ribosome Inactivating Proteins
  • Ribosome Inactivating Proteins, Type 2
  • Toxins, Biological / therapeutic use*
  • Vimentin / analysis
  • Vimentin / metabolism

Substances

  • Antineoplastic Agents
  • Lamin Type B
  • Paxillin
  • Plant Preparations
  • Plant Proteins
  • RNA, Messenger
  • Ribosome Inactivating Proteins, Type 2
  • Toxins, Biological
  • VAA-I protein, Viscum album
  • Vimentin
  • Ribosome Inactivating Proteins
  • Caspases
  • Nonmuscle Myosin Type IIA