Abstract
The retinoblastoma protein family has been implicated in growth control and modulation of the activity of genes involved in cell proliferation, such as B-myb. Recent evidence indicates that the product of the B-myb gene is necessary for the growth and survival of several human and murine cell lines. Upon overexpression, B-myb induces deregulated cell growth of certain cell lines. Here we show that B-myb overexpression is able to induce DNA synthesis in p107 growth-arrested human osteosarcoma cells (SAOS2). p107 might exert its growth-suppressive activity by regulating B-myb gene transcription. Indeed, p107 down-modulated B-myb promoter activity and drastically decreased E2F-mediated transactivation. Finally, B-myb was able to stimulate DNA synthesis of both stably and transiently transfected human glioblastoma cells (T98G). Altogether, these data provide definitive evidence that the human B-myb protein is involved in growth control of human cells, and that p107 has a significant role in regulating B-myb gene activity.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, P.H.S.
MeSH terms
-
Adenovirus E2 Proteins / metabolism
-
Animals
-
Bone Neoplasms
-
Cell Cycle Proteins*
-
Cell Cycle*
-
Cell Division
-
Cell Line
-
Cell Survival
-
DNA Replication
-
DNA-Binding Proteins / biosynthesis
-
DNA-Binding Proteins / metabolism*
-
Gene Expression Regulation, Neoplastic
-
Glioblastoma
-
Homeostasis
-
Humans
-
Kinetics
-
Luciferases / biosynthesis
-
Luciferases / metabolism
-
Mice
-
Nuclear Proteins / metabolism*
-
Oncogenes
-
Osteosarcoma
-
Plasmids
-
Recombinant Proteins / metabolism
-
Retinoblastoma Protein / biosynthesis
-
Retinoblastoma-Like Protein p107
-
S Phase
-
Trans-Activators*
-
Transcription Factors / biosynthesis
-
Transcription Factors / metabolism*
-
Transcription, Genetic
-
Transcriptional Activation
-
Transfection
-
Tumor Cells, Cultured
Substances
-
Adenovirus E2 Proteins
-
Cell Cycle Proteins
-
DNA-Binding Proteins
-
MYBL2 protein, human
-
Mybl2 protein, mouse
-
Nuclear Proteins
-
RBL1 protein, human
-
Rbl1 protein, mouse
-
Recombinant Proteins
-
Retinoblastoma Protein
-
Retinoblastoma-Like Protein p107
-
Trans-Activators
-
Transcription Factors
-
Luciferases