pRB and p107 have distinct effects when expressed in pRB-deficient tumor cells at physiologically relevant levels

H. Jiang, A. N. Karnezis, M. Tao, P. M. Guida, L. Zhu

Research output: Contribution to journalArticle

16 Scopus citations


A key difference among the three structurally similar pRB family members is that only pRB is a tumor suppressor. Identification of distinctive functional differences between pRB and p107/p130 therefore holds promise for a better understanding of the tumor suppression mechanisms of pRB. Enigmatically, pRB and p107 have been shown to have indistinguishable growth suppression activities when studied in the pRB-deficient Saos-2 cell system. In this study, we discovered that, when expressed at physiologically relevant levels, pRB and p107 had distinctive effects in causing growth suppression, pRB induced cellular p130 levels while p107 repressed them. p107, but not pRB, blocked cells inside S phase in addition to G1 arrest. In contrast, no qualitative differences were identified in their abilities to repress the expression of a set of suspected pRB/E2F repression target genes. These results indicate that pRB and p107 possess different growth suppression effects, despite the fact that they have similar E2F repression effects.

Original languageEnglish (US)
Pages (from-to)3878-3887
Number of pages10
Issue number34
Publication statusPublished - Aug 10 2000



  • E2F
  • Growth suppression
  • Retinoblastoma protein
  • Tumor suppressor
  • p107

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research

Cite this