Abstract
Two human erythroleukemia cell lines, HEL and K562, express transglutaminase activity. The enzyme was identified as a tissue transglutaminase following chromatographic purification. All-trans-retinoic acid (10 µm) stimulated differentiation in HEL cells as judged by a 4-fold increase in hemoglobin content and a reduction in cell proliferation. The transglutaminase activity increased 9-fold. This increase in transglutaminase was the result of a pretranslational regulation of the gene as revealed by Northern blot analysis of mRNA. These changes were not a result of cell apoptosis, since parallel DNA degradation catalyzed by a Ca2+-dependent endonuclease could not be demonstrated. The K562 cells, in contrast, showed no transglutaminase induction following exposure to retinoic acid and displayed no changes in maturation markers or cell growth.
Footnotes
- Received March 26, 1990.
- Accepted September 10, 1990.
- ©1990 American Association for Cancer Research.
Volume 50, Issue 24
