p53 controls proliferation of early B lineage cells by a p21 (WAF1/Cip1)-independent pathway.
We examined a role of p53 in early B cell development using fetal liver (FL) cells from p53 deficient (-/-) mice. Expression of p53 was detected in early B lineage (pre-B) cells developed in the stromal cell-dependent FL cell culture. Proliferation of the pre-B cells from the p53(-/-) mice was augmented, suggesting that p53 negatively regulates proliferation of pre-B cells. Although p21 (WAF1/Cip1) is a downstream effector of p53 and mediates growth arrest by inhibiting the action of cyclin-dependent kinases, expression of p21 was also induced in the pre-B cells from p53(-/-) mice. These results indicate that expression of the p21 in pre-B cells is independent of p53 and that the regulatory effect of p53 on proliferation of pre-B cells is mediated by a p21-independent pathway.
Hu
L
L
Division of Developmental Genetics, Chiba University School of Medicine, Japan.
Aizawa
S
S
Tokuhisa
T
T
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002455:Cell Division; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D015851:Interleukin-7 / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D015851:Interleukin-7; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53