Retinoic acid induction of nuclear envelope-limited chromatin sheets in HL-60

Exp Cell Res. 1998 Nov 25;245(1):91-104. doi: 10.1006/excr.1998.4210.


Exposure of the human leukemic cell line (HL-60) to 1 microM retinoic acid (RA) induces in vitro granulopoiesis, including the development of lobulated nuclei. Ultrastructural studies, presented here, demonstrate the formation of extensive quantities of nuclear envelope-limited chromatin sheets (ELCS), in addition to nuclear lobulation, following treatment with RA. ELCS contain DNA, as shown by the Feulgen-like electron microscope stain osmium ammine-B. Lamin B was demonstrated in ELCS by immunoelectron microscopy with colloidal gold-labeled antibody. Formation of ELCS occurred in Bcl2-overexpressing HL-60 cell sublines with suppressed apoptotic cell death, indicating separable mechanisms for ELCS formation and apoptosis. Immunofluorescent and immunoblotting procedures demonstrated modulations in the amounts and distribution of nuclear envelope-associated components. Total amounts of lamins A/C and cytoplasmic vimentin were reduced by RA treatment. The amounts of lamin B, lamin B receptor (LBR), and lamina-associated polypeptide 2 (LAP2) did not exhibit significant quantitative changes, but acquired heterogeneous staining patterns on the nuclear envelope. RA induced the appearance of low-molecular-weight LBR-related proteins. This study demonstrated the parallel induction of lobulated nuclei and of ELCS and the modulation of nuclear envelope components following exposure of HL-60 to retinoic acid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Chromatin / drug effects*
  • Chromatin / ultrastructure
  • HL-60 Cells
  • Humans
  • Immunoblotting
  • Mitogens / pharmacology*
  • Nuclear Envelope / drug effects
  • Nuclear Envelope / metabolism
  • Nuclear Envelope / ultrastructure
  • Nuclear Proteins / metabolism
  • Tretinoin / pharmacology*


  • Chromatin
  • Mitogens
  • Nuclear Proteins
  • Tretinoin