Abstract
Tissue homeostasis and the prevention of neoplasia require regulatory co-ordination between cellular proliferation and apoptosis. Several cellular proteins, including c-myc and E2F, as well as viral proteins such as E1A, have dual functions as positive regulators of apoptosis and proliferation. The product of the retinoblastoma tumor suppressor gene, pRb, binds these proteins and is known to function in growth suppression. To examine whether pRb may function as a negative regulator of both proliferation and apoptosis, we analyzed apoptosis induced in transfected derivatives of the human osteosarcoma cell line SAOS-2. Ionizing radiation induced apoptosis in a time- and dose-dependent manner in SAOS-2 cells, which lack pRb expression. In both a transient and stable transfection assay, SAOS-2 derivatives expressing wild-type (wt) pRb exhibited increased viability and decreased apoptosis following treatment at a variety of radiation doses. Expression in SAOS-2 of a mutant pRb that fails to complex with several known binding partners of pRb, including E1A and E2F, did not protect SAOS-2 cells from apoptosis. Radiation exposure induced a G2 arrest in SAOS-2 and in derivatives expressing pRb. Inhibition of DNA synthesis and cell cycle progression by aphidicolin treatment failed to protect SAOS-2 cells or pRb-expressing isolates from undergoing apoptosis. Our data document a novel function for pRb in suppressing apoptosis and suggest that several proteins shown to induce apoptosis, including E1A, E2F and c-myc, may do so by interfering with the protective function of pRb.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Albright N. Computer programs for the analysis of cellular survival data. Radiat Res. 1987 Nov;112(2):331–340. [PubMed] [Google Scholar]
- Aoshima J., Kubota M., Nishimura T., Iwamura T. DNA polymerases of Chlorella. II. Characterization to distinguish the two enzymes. J Biochem. 1984 Aug;96(2):461–473. doi: 10.1093/oxfordjournals.jbchem.a134858. [DOI] [PubMed] [Google Scholar]
- Askew D. S., Ashmun R. A., Simmons B. C., Cleveland J. L. Constitutive c-myc expression in an IL-3-dependent myeloid cell line suppresses cell cycle arrest and accelerates apoptosis. Oncogene. 1991 Oct;6(10):1915–1922. [PubMed] [Google Scholar]
- Baldin V., Lukas J., Marcote M. J., Pagano M., Draetta G. Cyclin D1 is a nuclear protein required for cell cycle progression in G1. Genes Dev. 1993 May;7(5):812–821. doi: 10.1101/gad.7.5.812. [DOI] [PubMed] [Google Scholar]
- Belli J. A., Shelton M. Potentially lethal radiation damage: repair by mammalian cells in culture. Science. 1969 Aug 1;165(3892):490–492. doi: 10.1126/science.165.3892.490. [DOI] [PubMed] [Google Scholar]
- 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]
- Buchkovich K., Duffy L. A., Harlow E. The retinoblastoma protein is phosphorylated during specific phases of the cell cycle. Cell. 1989 Sep 22;58(6):1097–1105. doi: 10.1016/0092-8674(89)90508-4. [DOI] [PubMed] [Google Scholar]
- Chellappan S. P., Hiebert S., Mudryj M., Horowitz J. M., Nevins J. R. The E2F transcription factor is a cellular target for the RB protein. Cell. 1991 Jun 14;65(6):1053–1061. doi: 10.1016/0092-8674(91)90557-f. [DOI] [PubMed] [Google Scholar]
- 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]
- Clarke A. R., Purdie C. A., Harrison D. J., Morris R. G., Bird C. C., Hooper M. L., Wyllie A. H. Thymocyte apoptosis induced by p53-dependent and independent pathways. Nature. 1993 Apr 29;362(6423):849–852. doi: 10.1038/362849a0. [DOI] [PubMed] [Google Scholar]
- Clem R. J., Fechheimer M., Miller L. K. Prevention of apoptosis by a baculovirus gene during infection of insect cells. Science. 1991 Nov 29;254(5036):1388–1390. doi: 10.1126/science.1962198. [DOI] [PubMed] [Google Scholar]
- Cohen J. J., Duke R. C., Fadok V. A., Sellins K. S. Apoptosis and programmed cell death in immunity. Annu Rev Immunol. 1992;10:267–293. doi: 10.1146/annurev.iy.10.040192.001411. [DOI] [PubMed] [Google Scholar]
- Colombel M., Olsson C. A., Ng P. Y., Buttyan R. Hormone-regulated apoptosis results from reentry of differentiated prostate cells onto a defective cell cycle. Cancer Res. 1992 Aug 15;52(16):4313–4319. [PubMed] [Google Scholar]
- Darzynkiewicz Z., Bruno S., Del Bino G., Gorczyca W., Hotz M. A., Lassota P., Traganos F. Features of apoptotic cells measured by flow cytometry. Cytometry. 1992;13(8):795–808. doi: 10.1002/cyto.990130802. [DOI] [PubMed] [Google Scholar]
- DeCaprio J. A., Ludlow J. W., Figge J., Shew J. Y., Huang C. M., Lee W. H., Marsilio E., Paucha E., Livingston D. M. SV40 large tumor antigen forms a specific complex with the product of the retinoblastoma susceptibility gene. Cell. 1988 Jul 15;54(2):275–283. doi: 10.1016/0092-8674(88)90559-4. [DOI] [PubMed] [Google Scholar]
- Denekamp J. Cell kinetics and radiation biology. Int J Radiat Biol Relat Stud Phys Chem Med. 1986 Feb;49(2):357–380. doi: 10.1080/09553008514552591. [DOI] [PubMed] [Google Scholar]
- Dive C., Gregory C. D., Phipps D. J., Evans D. L., Milner A. E., Wyllie A. H. Analysis and discrimination of necrosis and apoptosis (programmed cell death) by multiparameter flow cytometry. Biochim Biophys Acta. 1992 Feb 3;1133(3):275–285. doi: 10.1016/0167-4889(92)90048-g. [DOI] [PubMed] [Google Scholar]
- Dou Q. P., Fridovich-Keil J. L., Pardee A. B. Inducible proteins binding to the murine thymidine kinase promoter in late G1/S phase. Proc Natl Acad Sci U S A. 1991 Feb 15;88(4):1157–1161. doi: 10.1073/pnas.88.4.1157. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dowdy S. F., Hinds P. W., Louie K., Reed S. I., Arnold A., Weinberg R. A. Physical interaction of the retinoblastoma protein with human D cyclins. Cell. 1993 May 7;73(3):499–511. doi: 10.1016/0092-8674(93)90137-f. [DOI] [PubMed] [Google Scholar]
- Dyson N., Guida P., Münger K., Harlow E. Homologous sequences in adenovirus E1A and human papillomavirus E7 proteins mediate interaction with the same set of cellular proteins. J Virol. 1992 Dec;66(12):6893–6902. doi: 10.1128/jvi.66.12.6893-6902.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dyson N., Howley P. M., Münger K., Harlow E. The human papilloma virus-16 E7 oncoprotein is able to bind to the retinoblastoma gene product. Science. 1989 Feb 17;243(4893):934–937. doi: 10.1126/science.2537532. [DOI] [PubMed] [Google Scholar]
- ELKIND M. M., SUTTON-GILBERT H., MOSES W. B., ALESCIO T., SWAIN R. W. RADIATION RESPONSE OF MAMMALIAN CELLS GROWN IN CULTURE. V. TEMPERATURE DEPENDENCE OF THE REPAIR OF X-RAY DAMAGE IN SURVIVING CELLS (AEROBIC AND HYPOXIC). Radiat Res. 1965 Jun;25:359–376. [PubMed] [Google Scholar]
- Eilers M., Schirm S., Bishop J. M. The MYC protein activates transcription of the alpha-prothymosin gene. EMBO J. 1991 Jan;10(1):133–141. doi: 10.1002/j.1460-2075.1991.tb07929.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- 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]
- Fairbairn L. J., Cowling G. J., Reipert B. M., Dexter T. M. Suppression of apoptosis allows differentiation and development of a multipotent hemopoietic cell line in the absence of added growth factors. Cell. 1993 Sep 10;74(5):823–832. doi: 10.1016/0092-8674(93)90462-y. [DOI] [PubMed] [Google Scholar]
- Fertil B., Malaise E. P. Intrinsic radiosensitivity of human cell lines is correlated with radioresponsiveness of human tumors: analysis of 101 published survival curves. Int J Radiat Oncol Biol Phys. 1985 Sep;11(9):1699–1707. doi: 10.1016/0360-3016(85)90223-8. [DOI] [PubMed] [Google Scholar]
- Freeman R. S., Estus S., Johnson E. M., Jr Analysis of cell cycle-related gene expression in postmitotic neurons: selective induction of Cyclin D1 during programmed cell death. Neuron. 1994 Feb;12(2):343–355. doi: 10.1016/0896-6273(94)90276-3. [DOI] [PubMed] [Google Scholar]
- Fung Y. K., T'Ang A., Murphree A. L., Zhang F. H., Qiu W. R., Wang S. W., Shi X. H., Lee L., Driscoll B., Wu K. J. The Rb gene suppresses the growth of normal cells. Oncogene. 1993 Oct;8(10):2659–2672. [PubMed] [Google Scholar]
- Gavrieli Y., Sherman Y., Ben-Sasson S. A. Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation. J Cell Biol. 1992 Nov;119(3):493–501. doi: 10.1083/jcb.119.3.493. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Golstein P., Ojcius D. M., Young J. D. Cell death mechanisms and the immune system. Immunol Rev. 1991 Jun;121:29–65. doi: 10.1111/j.1600-065x.1991.tb00822.x. [DOI] [PubMed] [Google Scholar]
- Goodrich D. W., Lee W. H. Abrogation by c-myc of G1 phase arrest induced by RB protein but not by p53. Nature. 1992 Nov 12;360(6400):177–179. doi: 10.1038/360177a0. [DOI] [PubMed] [Google Scholar]
- 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]
- Gregory C. D., Dive C., Henderson S., Smith C. A., Williams G. T., Gordon J., Rickinson A. B. Activation of Epstein-Barr virus latent genes protects human B cells from death by apoptosis. Nature. 1991 Feb 14;349(6310):612–614. doi: 10.1038/349612a0. [DOI] [PubMed] [Google Scholar]
- Haraguchi T., Oguro M., Nagano H., Ichihara A., Sakamura S. Specific inhibitors of eukaryotic DNA synthesis and DNA polymerase alpha, 3-deoxyaphidicolin and aphidicolin-17-monoacetate. Nucleic Acids Res. 1983 Feb 25;11(4):1197–1209. doi: 10.1093/nar/11.4.1197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hartwell L. H., Weinert T. A. Checkpoints: controls that ensure the order of cell cycle events. Science. 1989 Nov 3;246(4930):629–634. doi: 10.1126/science.2683079. [DOI] [PubMed] [Google Scholar]
- Helin K., Harlow E., Fattaey A. Inhibition of E2F-1 transactivation by direct binding of the retinoblastoma protein. Mol Cell Biol. 1993 Oct;13(10):6501–6508. doi: 10.1128/mcb.13.10.6501. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Helin K., Lees J. A., Vidal M., Dyson N., Harlow E., Fattaey A. A cDNA encoding a pRB-binding protein with properties of the transcription factor E2F. Cell. 1992 Jul 24;70(2):337–350. doi: 10.1016/0092-8674(92)90107-n. [DOI] [PubMed] [Google Scholar]
- Hershberger P. A., Dickson J. A., Friesen P. D. Site-specific mutagenesis of the 35-kilodalton protein gene encoded by Autographa californica nuclear polyhedrosis virus: cell line-specific effects on virus replication. J Virol. 1992 Sep;66(9):5525–5533. doi: 10.1128/jvi.66.9.5525-5533.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Huang H. J., Yee J. K., Shew J. Y., Chen P. L., Bookstein R., Friedmann T., Lee E. Y., Lee W. H. Suppression of the neoplastic phenotype by replacement of the RB gene in human cancer cells. Science. 1988 Dec 16;242(4885):1563–1566. doi: 10.1126/science.3201247. [DOI] [PubMed] [Google Scholar]
- Iavarone A., Garg P., Lasorella A., Hsu J., Israel M. A. The helix-loop-helix protein Id-2 enhances cell proliferation and binds to the retinoblastoma protein. Genes Dev. 1994 Jun 1;8(11):1270–1284. doi: 10.1101/gad.8.11.1270. [DOI] [PubMed] [Google Scholar]
- Kaelin W. G., Jr, Krek W., Sellers W. R., DeCaprio J. A., Ajchenbaum F., Fuchs C. S., Chittenden T., Li Y., Farnham P. J., Blanar M. A. Expression cloning of a cDNA encoding a retinoblastoma-binding protein with E2F-like properties. Cell. 1992 Jul 24;70(2):351–364. doi: 10.1016/0092-8674(92)90108-o. [DOI] [PubMed] [Google Scholar]
- 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]
- Kuerbitz S. J., Plunkett B. S., Walsh W. V., Kastan M. B. Wild-type p53 is a cell cycle checkpoint determinant following irradiation. Proc Natl Acad Sci U S A. 1992 Aug 15;89(16):7491–7495. doi: 10.1073/pnas.89.16.7491. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee S., Christakos S., Small M. B. Apoptosis and signal transduction: clues to a molecular mechanism. Curr Opin Cell Biol. 1993 Apr;5(2):286–291. doi: 10.1016/0955-0674(93)90118-a. [DOI] [PubMed] [Google Scholar]
- Leeper D. B., Schneiderman M. H., Dewey W. C. Radiation-induced division delay in synchronized Chinese hamster ovary cells in monolayer culture. Radiat Res. 1972 May;50(2):401–417. [PubMed] [Google Scholar]
- 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]
- Lowe S. W., Schmitt E. M., Smith S. W., Osborne B. A., Jacks T. p53 is required for radiation-induced apoptosis in mouse thymocytes. Nature. 1993 Apr 29;362(6423):847–849. doi: 10.1038/362847a0. [DOI] [PubMed] [Google Scholar]
- 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]
- Münger K., Werness B. A., Dyson N., Phelps W. C., Harlow E., Howley P. M. Complex formation of human papillomavirus E7 proteins with the retinoblastoma tumor suppressor gene product. EMBO J. 1989 Dec 20;8(13):4099–4105. doi: 10.1002/j.1460-2075.1989.tb08594.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Nicoletti I., Migliorati G., Pagliacci M. C., Grignani F., Riccardi C. A rapid and simple method for measuring thymocyte apoptosis by propidium iodide staining and flow cytometry. J Immunol Methods. 1991 Jun 3;139(2):271–279. doi: 10.1016/0022-1759(91)90198-o. [DOI] [PubMed] [Google Scholar]
- Olive P. L., Wlodek D., Banáth J. P. DNA double-strand breaks measured in individual cells subjected to gel electrophoresis. Cancer Res. 1991 Sep 1;51(17):4671–4676. [PubMed] [Google Scholar]
- Oppenheim R. W. Cell death during development of the nervous system. Annu Rev Neurosci. 1991;14:453–501. doi: 10.1146/annurev.ne.14.030191.002321. [DOI] [PubMed] [Google Scholar]
- Painter R. B., Young B. R. Radiosensitivity in ataxia-telangiectasia: a new explanation. Proc Natl Acad Sci U S A. 1980 Dec;77(12):7315–7317. doi: 10.1073/pnas.77.12.7315. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Pear W. S., Nolan G. P., Scott M. L., Baltimore D. Production of high-titer helper-free retroviruses by transient transfection. Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8392–8396. doi: 10.1073/pnas.90.18.8392. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Price A. The repair of ionising radiation-induced damage to DNA. Semin Cancer Biol. 1993 Apr;4(2):61–71. [PubMed] [Google Scholar]
- Qin X. Q., Chittenden T., Livingston D. M., Kaelin W. G., Jr Identification of a growth suppression domain within the retinoblastoma gene product. Genes Dev. 1992 Jun;6(6):953–964. doi: 10.1101/gad.6.6.953. [DOI] [PubMed] [Google Scholar]
- Quelle D. E., Ashmun R. A., Shurtleff S. A., Kato J. Y., Bar-Sagi D., Roussel M. F., Sherr C. J. Overexpression of mouse D-type cyclins accelerates G1 phase in rodent fibroblasts. Genes Dev. 1993 Aug;7(8):1559–1571. doi: 10.1101/gad.7.8.1559. [DOI] [PubMed] [Google Scholar]
- Radford I. R., Murphy T. K., Radley J. M., Ellis S. L. Radiation response of mouse lymphoid and myeloid cell lines. Part II. Apoptotic death is shown by all lines examined. Int J Radiat Biol. 1994 Feb;65(2):217–227. doi: 10.1080/09553009414550251. [DOI] [PubMed] [Google Scholar]
- Rao L., Debbas M., Sabbatini P., Hockenbery D., Korsmeyer S., White E. The adenovirus E1A proteins induce apoptosis, which is inhibited by the E1B 19-kDa and Bcl-2 proteins. Proc Natl Acad Sci U S A. 1992 Aug 15;89(16):7742–7746. doi: 10.1073/pnas.89.16.7742. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rothenberg E. V. The development of functionally responsive T cells. Adv Immunol. 1992;51:85–214. doi: 10.1016/s0065-2776(08)60487-3. [DOI] [PubMed] [Google Scholar]
- Rustgi A. K., Dyson N., Bernards R. Amino-terminal domains of c-myc and N-myc proteins mediate binding to the retinoblastoma gene product. Nature. 1991 Aug 8;352(6335):541–544. doi: 10.1038/352541a0. [DOI] [PubMed] [Google Scholar]
- Sarkar A., Dolan M. E., Gonzalez G. G., Marton L. J., Pegg A. E., Deen D. F. The effects of O6-benzylguanine and hypoxia on the cytotoxicity of 1,3-bis(2-chloroethyl)-1-nitrosourea in nitrosourea-resistant SF-763 cells. Cancer Chemother Pharmacol. 1993;32(6):477–481. doi: 10.1007/BF00685893. [DOI] [PubMed] [Google Scholar]
- Shew J. Y., Lin B. T., Chen P. L., Tseng B. Y., Yang-Feng T. L., Lee W. H. C-terminal truncation of the retinoblastoma gene product leads to functional inactivation. Proc Natl Acad Sci U S A. 1990 Jan;87(1):6–10. doi: 10.1073/pnas.87.1.6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shibuya H., Yoneyama M., Ninomiya-Tsuji J., Matsumoto K., Taniguchi T. IL-2 and EGF receptors stimulate the hematopoietic cell cycle via different signaling pathways: demonstration of a novel role for c-myc. Cell. 1992 Jul 10;70(1):57–67. doi: 10.1016/0092-8674(92)90533-i. [DOI] [PubMed] [Google Scholar]
- 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]
- Story M. D., Mendoza E. A., Meyn R. E., Tofilon P. J. Pulsed-field gel electrophoretic analysis of DNA double-strand breaks in mammalian cells using photostimulable storage phosphor imaging. Int J Radiat Biol. 1994 May;65(5):523–528. doi: 10.1080/09553009414550611. [DOI] [PubMed] [Google Scholar]
- Strasser A., Harris A. W., Jacks T., Cory S. DNA damage can induce apoptosis in proliferating lymphoid cells via p53-independent mechanisms inhibitable by Bcl-2. Cell. 1994 Oct 21;79(2):329–339. doi: 10.1016/0092-8674(94)90201-1. [DOI] [PubMed] [Google Scholar]
- TERASIMA T., TOLMACH L. J. Variations in several responses of HeLa cells to x-irradiation during the division cycle. Biophys J. 1963 Jan;3:11–33. doi: 10.1016/s0006-3495(63)86801-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vaux D. L. Toward an understanding of the molecular mechanisms of physiological cell death. Proc Natl Acad Sci U S A. 1993 Feb 1;90(3):786–789. doi: 10.1073/pnas.90.3.786. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weichselbaum R. R. Cellular and molecular aspects of human tumor radioresistance. Important Adv Oncol. 1991:73–83. [PubMed] [Google Scholar]
- Weinert T. A., Hartwell L. H. The RAD9 gene controls the cell cycle response to DNA damage in Saccharomyces cerevisiae. Science. 1988 Jul 15;241(4863):317–322. doi: 10.1126/science.3291120. [DOI] [PubMed] [Google Scholar]
- White A. E., Livanos E. M., Tlsty T. D. Differential disruption of genomic integrity and cell cycle regulation in normal human fibroblasts by the HPV oncoproteins. Genes Dev. 1994 Mar 15;8(6):666–677. doi: 10.1101/gad.8.6.666. [DOI] [PubMed] [Google Scholar]
- Whyte P., Buchkovich K. J., Horowitz J. M., Friend S. H., Raybuck M., Weinberg R. A., Harlow E. Association between an oncogene and an anti-oncogene: the adenovirus E1A proteins bind to the retinoblastoma gene product. Nature. 1988 Jul 14;334(6178):124–129. doi: 10.1038/334124a0. [DOI] [PubMed] [Google Scholar]
- Williams G. T., Smith C. A. Molecular regulation of apoptosis: genetic controls on cell death. Cell. 1993 Sep 10;74(5):777–779. doi: 10.1016/0092-8674(93)90457-2. [DOI] [PubMed] [Google Scholar]
- 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]
- Yonish-Rouach E., Resnitzky D., Lotem J., Sachs L., Kimchi A., Oren M. Wild-type p53 induces apoptosis of myeloid leukaemic cells that is inhibited by interleukin-6. Nature. 1991 Jul 25;352(6333):345–347. doi: 10.1038/352345a0. [DOI] [PubMed] [Google Scholar]
- Zhu L., van den Heuvel S., Helin K., Fattaey A., Ewen M., Livingston D., Dyson N., Harlow E. Inhibition of cell proliferation by p107, a relative of the retinoblastoma protein. Genes Dev. 1993 Jul;7(7A):1111–1125. doi: 10.1101/gad.7.7a.1111. [DOI] [PubMed] [Google Scholar]