p130/pRb2 has growth suppressive properties similar to yet distinctive from those of retinoblastoma family members pRb and p107.
The retinoblastoma tumor suppressor gene product, as well as its related protein p107, has been shown clearly to exert its growth suppressive effects in a cell cycle dependent manner. In this study we demonstrate that the introduction of our recently cloned Rb family member p130/pRb2 causes growth arrest in three tumor cell lines. In addition, in the nasopharyngeal carcinoma derived cell line HONE-1, we identified a low level of expression of p130/pRb2, possibly due to gene rearrangement, and a drastic reduction in proliferation upon introduction of a constitutive active p130/pRb2 complementary DNA clone. Furthermore, we were able to dissect distinct properties of the Rb family by demonstrating that p130/pRb2 inhibits proliferation of the glioblastoma cell line T98G, which is resistant to the growth suppressive effects of both pRb and p107. Our studies demonstrate that the Rb family proteins identified to date may complement each other but they are not fully functionally redundant.
Claudio
P P
PP
Department of Pathology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Howard
C M
CM
Baldi
A
A
De Luca
A
A
Fu
Y
Y
Condorelli
G
G
Sun
Y
Y
Colburn
N
N
Calabretta
B
B
Giordano
A
A
D002455:Cell Division; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism / Q000502:physiology*; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay
D009687:Nuclear Proteins; D010750:Phosphoproteins; D011506:Proteins; C493844:RBL1 protein, human; C493837:RBL2 protein, human; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130