Increased HoxB4 Inhibits Apoptotic Cell Death in Pro-B Cells.
HoxB4, a homeodomain-containing transcription factor, is involved in the expansion of hematopoietic stem cells and progenitor cells in vivo and in vitro, and plays a key role in regulating the balance between hematopoietic stem cell renewal and cell differentiation. However, the biological activity of HoxB4 in other cells has not been reported. In this study, we investigated the effect of overexpressed HoxB4 on cell survival under various conditions that induce death, using the Ba/F3 cell line. Analysis of phenotypical characteristics showed that HoxB4 overexpression in Ba/F3 cells reduced cell size, death, and proliferation rate. Moreover, the progression from early to late apoptotic stages was inhibited in Ba/F3 cells subjected to HoxB4 overexpression under removal of interleukin-3-mediated signal, leading to the induction of cell cycle arrest at the G2/M phase and attenuated cell death by Fas protein stimulation in vitro. Furthermore, apoptotic cell death induced by doxorubicin-treated G2/M phase cell-cycle arrest also decreased with HoxB4 overexpression in Ba/F3 cells. From these data, we suggest that HoxB4 may play an important role in the regulation of pro-B cell survival under various apoptotic death environments.
Department of Biomedical Science, College of Life Science, CHA University, Seongnam 463-712, Korea.
Sung-Won
SW
Park
Kyung-Jong
KJ
Won
Yong-Soo
YS
Lee
Hye Sun
HS
Kim
Yu-Kyung
YK
Kim
Hyeon-Woo
HW
Lee
Bokyung
B
Kim
Byeong Han
BH
Lee
Jin-Hoi
JH
Kim
Dong-Ku
DK
Kim