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. 1995 Jun 6;92(12):5436–5440. doi: 10.1073/pnas.92.12.5436

Deficiency of retinoblastoma protein leads to inappropriate S-phase entry, activation of E2F-responsive genes, and apoptosis.

A Almasan 1, Y Yin 1, R E Kelly 1, E Y Lee 1, A Bradley 1, W Li 1, J R Bertino 1, G M Wahl 1
PMCID: PMC41709  PMID: 7777526

Abstract

The retinoblastoma susceptibility gene (Rb) participates in controlling the G1/S-phase transition, presumably by binding and inactivating E2F transcription activator family members. Mouse embryonic fibroblasts (MEFs) with no, one, or two inactivated Rb genes were used to determine the specific contributions of Rb protein to cell cycle progression and gene expression. MEFs lacking both Rb alleles (Rb-/-) entered S phase in the presence of the dihydrofolate reductase inhibitor methotrexate. Two E2F target genes, dihydrofolate reductase and thymidylate synthase, displayed elevated mRNA and protein levels in Rb- MEFs. Since absence of functional Rb protein in MEFs is sufficient for S-phase entry under growth-limiting conditions, these data indicate that the E2F complexes containing Rb protein, and not the Rb-related proteins p107 and p130, may be rate limiting for the G1/S transition. Antineoplastic drugs caused accumulation of p53 in the nuclei of both Rb+/+ and Rb-/- MEFs. While p53 induction led to apoptosis in Rb-/- MEFs, Rb+/- and Rb+/+ MEFs underwent cell cycle arrest without apoptosis. These results reveal that diverse growth signals work through Rb to regulate entry into S phase, and they indicate that absence of Rb protein produces a constitutive DNA replication signal capable of activating a p53-associated apoptotic response.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Almasan A., Linke S. P., Paulson T. G., Huang L. C., Wahl G. M. Genetic instability as a consequence of inappropriate entry into and progression through S-phase. Cancer Metastasis Rev. 1995 Mar;14(1):59–73. doi: 10.1007/BF00690212. [DOI] [PubMed] [Google Scholar]
  2. Blake M. C., Azizkhan J. C. Transcription factor E2F is required for efficient expression of the hamster dihydrofolate reductase gene in vitro and in vivo. Mol Cell Biol. 1989 Nov;9(11):4994–5002. doi: 10.1128/mcb.9.11.4994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Chen P. L., Scully P., Shew J. Y., Wang J. Y., Lee W. H. Phosphorylation of the retinoblastoma gene product is modulated during the cell cycle and cellular differentiation. Cell. 1989 Sep 22;58(6):1193–1198. doi: 10.1016/0092-8674(89)90517-5. [DOI] [PubMed] [Google Scholar]
  4. Clarke A. R., Maandag E. R., van Roon M., van der Lugt N. M., van der Valk M., Hooper M. L., Berns A., te Riele H. Requirement for a functional Rb-1 gene in murine development. Nature. 1992 Sep 24;359(6393):328–330. doi: 10.1038/359328a0. [DOI] [PubMed] [Google Scholar]
  5. Cobrinik D., Whyte P., Peeper D. S., Jacks T., Weinberg R. A. Cell cycle-specific association of E2F with the p130 E1A-binding protein. Genes Dev. 1993 Dec;7(12A):2392–2404. doi: 10.1101/gad.7.12a.2392. [DOI] [PubMed] [Google Scholar]
  6. DeCaprio J. A., Furukawa Y., Ajchenbaum F., Griffin J. D., Livingston D. M. The retinoblastoma-susceptibility gene product becomes phosphorylated in multiple stages during cell cycle entry and progression. Proc Natl Acad Sci U S A. 1992 Mar 1;89(5):1795–1798. doi: 10.1073/pnas.89.5.1795. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Demers G. W., Foster S. A., Halbert C. L., Galloway D. A. Growth arrest by induction of p53 in DNA damaged keratinocytes is bypassed by human papillomavirus 16 E7. Proc Natl Acad Sci U S A. 1994 May 10;91(10):4382–4386. doi: 10.1073/pnas.91.10.4382. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Deng T. L., Li D. W., Jenh C. H., Johnson L. F. Structure of the gene for mouse thymidylate synthase. Locations of introns and multiple transcriptional start sites. J Biol Chem. 1986 Dec 5;261(34):16000–16005. [PubMed] [Google Scholar]
  9. Di Leonardo A., Linke S. P., Clarkin K., Wahl G. M. DNA damage triggers a prolonged p53-dependent G1 arrest and long-term induction of Cip1 in normal human fibroblasts. Genes Dev. 1994 Nov 1;8(21):2540–2551. doi: 10.1101/gad.8.21.2540. [DOI] [PubMed] [Google Scholar]
  10. Donehower L. A., Harvey M., Slagle B. L., McArthur M. J., Montgomery C. A., Jr, Butel J. S., Bradley A. Mice deficient for p53 are developmentally normal but susceptible to spontaneous tumours. Nature. 1992 Mar 19;356(6366):215–221. doi: 10.1038/356215a0. [DOI] [PubMed] [Google Scholar]
  11. Evan G. I., Wyllie A. H., Gilbert C. S., Littlewood T. D., Land H., Brooks M., Waters C. M., Penn L. Z., Hancock D. C. Induction of apoptosis in fibroblasts by c-myc protein. Cell. 1992 Apr 3;69(1):119–128. doi: 10.1016/0092-8674(92)90123-t. [DOI] [PubMed] [Google Scholar]
  12. Ewen M. E., Sluss H. K., Sherr C. J., Matsushime H., Kato J., Livingston D. M. Functional interactions of the retinoblastoma protein with mammalian D-type cyclins. Cell. 1993 May 7;73(3):487–497. doi: 10.1016/0092-8674(93)90136-e. [DOI] [PubMed] [Google Scholar]
  13. Farnham P. J., Slansky J. E., Kollmar R. The role of E2F in the mammalian cell cycle. Biochim Biophys Acta. 1993 Aug 23;1155(2):125–131. doi: 10.1016/0304-419x(93)90001-s. [DOI] [PubMed] [Google Scholar]
  14. Gaudray P., Trotter J., Wahl G. M. Fluorescent methotrexate labeling and flow cytometric analysis of cells containing low levels of dihydrofolate reductase. J Biol Chem. 1986 May 15;261(14):6285–6292. [PubMed] [Google Scholar]
  15. Goodrich D. W., Wang N. P., Qian Y. W., Lee E. Y., Lee W. H. The retinoblastoma gene product regulates progression through the G1 phase of the cell cycle. Cell. 1991 Oct 18;67(2):293–302. doi: 10.1016/0092-8674(91)90181-w. [DOI] [PubMed] [Google Scholar]
  16. Hamel P. A., Phillips R. A., Muncaster M., Gallie B. L. Speculations on the roles of RB1 in tissue-specific differentiation, tumor initiation, and tumor progression. FASEB J. 1993 Jul;7(10):846–854. doi: 10.1096/fasebj.7.10.8344484. [DOI] [PubMed] [Google Scholar]
  17. Hatakeyama M., Brill J. A., Fink G. R., Weinberg R. A. Collaboration of G1 cyclins in the functional inactivation of the retinoblastoma protein. Genes Dev. 1994 Aug 1;8(15):1759–1771. doi: 10.1101/gad.8.15.1759. [DOI] [PubMed] [Google Scholar]
  18. Hinds P. W., Mittnacht S., Dulic V., Arnold A., Reed S. I., Weinberg R. A. Regulation of retinoblastoma protein functions by ectopic expression of human cyclins. Cell. 1992 Sep 18;70(6):993–1006. doi: 10.1016/0092-8674(92)90249-c. [DOI] [PubMed] [Google Scholar]
  19. Howes K. A., Ransom N., Papermaster D. S., Lasudry J. G., Albert D. M., Windle J. J. Apoptosis or retinoblastoma: alternative fates of photoreceptors expressing the HPV-16 E7 gene in the presence or absence of p53. Genes Dev. 1994 Jun 1;8(11):1300–1310. doi: 10.1101/gad.8.11.1300. [DOI] [PubMed] [Google Scholar]
  20. Jacks T., Fazeli A., Schmitt E. M., Bronson R. T., Goodell M. A., Weinberg R. A. Effects of an Rb mutation in the mouse. Nature. 1992 Sep 24;359(6393):295–300. doi: 10.1038/359295a0. [DOI] [PubMed] [Google Scholar]
  21. Johnson D. G., Schwarz J. K., Cress W. D., Nevins J. R. Expression of transcription factor E2F1 induces quiescent cells to enter S phase. Nature. 1993 Sep 23;365(6444):349–352. doi: 10.1038/365349a0. [DOI] [PubMed] [Google Scholar]
  22. Kastan M. B., Zhan Q., el-Deiry W. S., Carrier F., Jacks T., Walsh W. V., Plunkett B. S., Vogelstein B., Fornace A. J., Jr A mammalian cell cycle checkpoint pathway utilizing p53 and GADD45 is defective in ataxia-telangiectasia. Cell. 1992 Nov 13;71(4):587–597. doi: 10.1016/0092-8674(92)90593-2. [DOI] [PubMed] [Google Scholar]
  23. Kaufman R. J., Bertino J. R., Schimke R. T. Quantitation of dihydrofolate reductase in individual parental and methotrexate-resistant murine cells. Use of a fluorescence activated cell sorter. J Biol Chem. 1978 Aug 25;253(16):5852–5860. [PubMed] [Google Scholar]
  24. Laborda J. 36B4 cDNA used as an estradiol-independent mRNA control is the cDNA for human acidic ribosomal phosphoprotein PO. Nucleic Acids Res. 1991 Jul 25;19(14):3998–3998. doi: 10.1093/nar/19.14.3998. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Lee E. Y., Chang C. Y., Hu N., Wang Y. C., Lai C. C., Herrup K., Lee W. H., Bradley A. Mice deficient for Rb are nonviable and show defects in neurogenesis and haematopoiesis. Nature. 1992 Sep 24;359(6393):288–294. doi: 10.1038/359288a0. [DOI] [PubMed] [Google Scholar]
  26. Lee E. Y., Hu N., Yuan S. S., Cox L. A., Bradley A., Lee W. H., Herrup K. Dual roles of the retinoblastoma protein in cell cycle regulation and neuron differentiation. Genes Dev. 1994 Sep 1;8(17):2008–2021. doi: 10.1101/gad.8.17.2008. [DOI] [PubMed] [Google Scholar]
  27. Lees J. A., Buchkovich K. J., Marshak D. R., Anderson C. W., Harlow E. The retinoblastoma protein is phosphorylated on multiple sites by human cdc2. EMBO J. 1991 Dec;10(13):4279–4290. doi: 10.1002/j.1460-2075.1991.tb05006.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Lin B. T., Gruenwald S., Morla A. O., Lee W. H., Wang J. Y. Retinoblastoma cancer suppressor gene product is a substrate of the cell cycle regulator cdc2 kinase. EMBO J. 1991 Apr;10(4):857–864. doi: 10.1002/j.1460-2075.1991.tb08018.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Lowe S. W., Ruley H. E., Jacks T., Housman D. E. p53-dependent apoptosis modulates the cytotoxicity of anticancer agents. Cell. 1993 Sep 24;74(6):957–967. doi: 10.1016/0092-8674(93)90719-7. [DOI] [PubMed] [Google Scholar]
  30. McIvor R. S., Simonsen C. C. Isolation and characterization of a variant dihydrofolate reductase cDNA from methotrexate-resistant murine L5178Y cells. Nucleic Acids Res. 1990 Dec 11;18(23):7025–7032. doi: 10.1093/nar/18.23.7025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Morgenbesser S. D., Williams B. O., Jacks T., DePinho R. A. p53-dependent apoptosis produced by Rb-deficiency in the developing mouse lens. Nature. 1994 Sep 1;371(6492):72–74. doi: 10.1038/371072a0. [DOI] [PubMed] [Google Scholar]
  32. Nevins J. R. E2F: a link between the Rb tumor suppressor protein and viral oncoproteins. Science. 1992 Oct 16;258(5081):424–429. doi: 10.1126/science.1411535. [DOI] [PubMed] [Google Scholar]
  33. Pan H., Griep A. E. Altered cell cycle regulation in the lens of HPV-16 E6 or E7 transgenic mice: implications for tumor suppressor gene function in development. Genes Dev. 1994 Jun 1;8(11):1285–1299. doi: 10.1101/gad.8.11.1285. [DOI] [PubMed] [Google Scholar]
  34. Slansky J. E., Li Y., Kaelin W. G., Farnham P. J. A protein synthesis-dependent increase in E2F1 mRNA correlates with growth regulation of the dihydrofolate reductase promoter. Mol Cell Biol. 1993 Mar;13(3):1610–1618. doi: 10.1128/mcb.13.3.1610. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Slebos R. J., Lee M. H., Plunkett B. S., Kessis T. D., Williams B. O., Jacks T., Hedrick L., Kastan M. B., Cho K. R. p53-dependent G1 arrest involves pRB-related proteins and is disrupted by the human papillomavirus 16 E7 oncoprotein. Proc Natl Acad Sci U S A. 1994 Jun 7;91(12):5320–5324. doi: 10.1073/pnas.91.12.5320. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Unger C., Kress S., Buchmann A., Schwarz M. Gamma-irradiation-induced micronuclei from mouse hepatoma cells accumulate high levels of the tumor suppressor protein p53. Cancer Res. 1994 Jul 15;54(14):3651–3655. [PubMed] [Google Scholar]
  37. Walker P. R., Kokileva L., LeBlanc J., Sikorska M. Detection of the initial stages of DNA fragmentation in apoptosis. Biotechniques. 1993 Dec;15(6):1032–1040. [PubMed] [Google Scholar]
  38. Wang J. Y., Knudsen E. S., Welch P. J. The retinoblastoma tumor suppressor protein. Adv Cancer Res. 1994;64:25–85. doi: 10.1016/s0065-230x(08)60834-9. [DOI] [PubMed] [Google Scholar]
  39. Wu X., Levine A. J. p53 and E2F-1 cooperate to mediate apoptosis. Proc Natl Acad Sci U S A. 1994 Apr 26;91(9):3602–3606. doi: 10.1073/pnas.91.9.3602. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Wyllie A. H. Glucocorticoid-induced thymocyte apoptosis is associated with endogenous endonuclease activation. Nature. 1980 Apr 10;284(5756):555–556. doi: 10.1038/284555a0. [DOI] [PubMed] [Google Scholar]
  41. Yin Y., Tainsky M. A., Bischoff F. Z., Strong L. C., Wahl G. M. Wild-type p53 restores cell cycle control and inhibits gene amplification in cells with mutant p53 alleles. Cell. 1992 Sep 18;70(6):937–948. doi: 10.1016/0092-8674(92)90244-7. [DOI] [PubMed] [Google Scholar]

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