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Gustavo Leone
Gustavo Leone, PhD 808 Biomedical Research Tower 460 W 12th Ave Columbus, OH 43210 614/688-4567 Fax: 614-688-4245 Dr. Leone's lab is currently studying the role of the Ras pathway in coordinating cell growth and cell death signals elicited by the E2F and Myc transcription programs. Uncontrolled cell proliferation is the hallmark of cancer, and tumor cells have typically acquired damage to genes that directly regulate their cell cycles. Mounting evidence implicates the E2F transcription family as an important regulator of the cell cycle. It is now clear that the disruption of various components of the pathway controlling E2F accumulation, either the activation of positive acting components such as Ras, Myc, G1 cyclins and their kinase subunits (CDKs), or the inactivation of negative components such as Rb, p53 and the CDK inhibitors (INK4 genes), can lead to the loss of cell growth control underlying the development of various forms of human cancer. Mammalian E2F is composed of a family of heterodimers encoded by six distinct genes. Our recent work has highlighted the roles of the E2F3 and E2F1 gene products as key regulators of cellular proliferation and apoptosis, respectively. The focus in my lab will be threefold. 1. First, using in vivo KO mouse models we will investigate the role of the E2F3 gene locus in the control of the cell cycle and cellular proliferation. The E2F3 locus encodes two distinct gene products, the E2F3a and E2F3b proteins. Particularly important is the observation that this novel E2F3b gene product is the predominant partner for the Rb tumor suppressor in non-proliferating cells. We will investigate the in vivo role of E2F3a in promoting cell cycle progression and the potential function of the novel E2F3b protein as a tumor suppressor. 2. Second, we will take advantage of a recombinant adenovirus expression system and of fibroblasts deficient for various cell cycle regulators in order to elucidate the mechanism by which E2F1 elicits an apoptotic signal. In addition we will employ fibroblasts deficient for E2F1, E2F2 and E2F3a/b in order to determine the relative contributions of these family members towards the E2F apoptotic program and to identify, using gene chip expression arrays, novel E2F targets important for executing the cell death program. 3. Finally, our lab is interested in determining how signal transduction pathways important for normal cellular proliferation may intersect and modulate E2F- and Myc-mediated apoptotic signals. In particular, our recent experiments have elucidated a Ras dependent pathway important for countering an E2F1- or Myc-mediated death signal, but the identity and regulation of the key activities important for coordinating these cell survival and cell death signals have yet to be determined. Through these studies we will not only further our molecular understanding of the control of cell growth and apoptosis, but we hope to also achieve an understanding of how these two fundamental processes are coordinated during the cell cycle to regulate normal proliferation, the disruption of which often leads to the development of human cancers. Education: University of Calgary, Calgary, Canada 1988 B.S. Biochemistry Professional Experience: 1987-88 Undergraduate Research Assistant, Department of Microbiology and Infectious Diseases, University of Calgary Honors: 1989-94 Alberta Heritage Foundation for Medical Research Studentship Publications Manuscripts (peer-reviewed publications)
1. Mah, D.C.W., Leone, G., Jankowski, J.M. and Lee, P.W.K. (1990). The N-terminal quarter of Reovirus cell attachment protein sigma1 possesses intrinsic virion-anchoring function. Virology 79:95-103. 2. Duncan, R., Horne, D., Strong, J.E., Leone, G., Pon, R.T., Yeung, M.C., and Lee, P.W.K. (1991). Conformational and functional analysis of the C-terminal globular head of the Reovirus cell attachment protein. Virology 182:810-819. 3. Strong, J.E., Leone, G., Duncan, R., Sharma, R.K. and Lee, P.W.K. (1991). Biochemical and biophysical characterization of the Reovirus cell attachment protein sigma1" Evidence that it is a homotrimer. Virology 184:23-32. 4. Leone, G., Duncan, R., and Lee, P.W.K. (1991). Trimerization of the Reovirus cell attachment protein (sigma1) induces conformational changes in sigma1 necessary for its cell binding function. Virology 184:758-761. 5. Leone, G., Mah, D.C.W. and Lee, P.W.K. (1991). The incorporation of Reovirus cell attachment protein sigma1 into virions requires the N-terminal hydrophobic tail and the adjacent heptad repeat region. Virology 182:346-350. 6. Leone, G., Duncan, R., Mah, D.C.W., Price, A., Cashdollar, L.W. and Lee, P.W.K. (1991). The N-terminal heptad repeat region of Reovirus cell attachment protein sigma1 is responsible for sigma1 oligomer stability and possesses intrinsic oligomerization function. Virology 182:336-345. 7. Leone, G., Maybaum, L. And Lee, P.W.K. (1992). The Reovirus cell attachment protein possesses two independently active trimerization domains: Basis of dominant negative effects. Cell 71:479-488. 8. Fernandes, J., Tang, D., Leone, G., and Lee, P.W.K. (1994). Binding of Reovirus to receptor leads to conformational changes in viral capsid proteins that are reversible upon virus detachment. J. Biol. Chem. 269 (25): 17043-17047. 9. Lee, P.W.K. and Leone, G. (1994). Reovirus Protein sigma1: From cell attachment to protein oligomerization and folding mechanisms. BioEssays 16:199-206. 10. DeGregori, J.*, Leone, G.*, Ohtani, K., Miron, A. and Nevins, J.R. (1995) E2F1 accumulation bypasses a G1 arrest resulting from the inhibition of G1 cyclin-dependent kinase activity. Genes & Development, 9:2873-2887. *These authors contributed equally to this work. 11. Gilmore, R., Coffey, M., Leone, G., McLure, K., Lee, P.W.K. (1996). Co-translational trimerization of the Reovirus cell attachment protein. The EMBO Journal 15(11):2651-2658. 12. Leone, G., Coffey, M., Gilmore, R., Duncan, R., and Lee, P.W.K. (1996) C-terminal Trimerization, but not N-terminal trimerization, of the Reovirus cell attachment protein is a post-translational and hsp70/ATP dependent process. J. Biol. Chem. 271 (14):8466-8471. 13. Smith, E., Leone, G., DeGregori, J., Jakoi, L., and Nevins, J.R. (1996). The accumulation of an E2F-p130 transcriptional repressor distinguishes a Go cell state from a G1 cell state. Mol. Cell. Biol. 16, 6965-6976. 14. Ohtani, K., DeGregori, J., Leone, G., Herendeen, D.R., Kelly, T.J., and Nevins, J.R. (1996). Expression of the HsOrc1 gene, a human ORC1 homolog, is regulated by cell proliferation via the E2F transcription factor. Mol. Cell. Biol. 16, 6977-6984. 15. DeGregori, J., Leone, G., Miron, A., Jakoi, L., and Nevins, J.R. (1997). Distinct roles for E2F proteins in cell growth control and apoptosis. Proc. Natl. Acad. Sci. USA. 94, 7245-7250. 16. Yan, Z., DeGregori, J., Shohet, R., Leone, G., Stillman, B., Nevins, J.R., Williams, R.S. (1997). Cdc6 is regulated by E2F and is essential for DNA replication in mammalian cells. Proc. Natl. Acad. Sci. USA. 95: 3603-3608 17. Leone, G., DeGregori, J., Sears, R., Jakoi, L., and Nevins, J.R. (1997). Myc and Ras collaborate in inducing accumulation of active cyclin E/Cdk2 and E2F. Nature. 387, 422-425. 18. Nevins, J.R., Leone, G., DeGregori, J., Jakoi, L. (1997). Role of the Rb/E2F pathway in cell growth control. J. Cell Physiol. 173: 233-236. 19. Nevins, J.R., DeGregori, J., Jakoi, L., and Leone, G. (1998). Functional analysis of E2F. Meth. Enzymol. (1998). 20. Kowalik, T.F., DeGregori, J., Leone, G., Jakoi, L., and Nevins, J.R. (1998). E2F1-Specific induction of apoptosis and p53 accumulation, which is blocked by Mdm2. Cell. Grow. & Diff. 9:113-118 21. Smith, J., Leone, G., Nevins, J.R. (1998). Distinct mechanisms control the accumulation of the Rb-related p107 and p130 proteins during cell growth. Cell. Grow. & Diff. 9:297-303. 22. Leone, G., DeGregori, J., Yan, Z., Jakoi, L., Ishida, S., Williams, R.S., Nevins, J.R. (1998). E2F3 activity is regulated during the cell cycle and is required for the induction of S phase. Genes & Development. 12:2120-2130. 23. Sears, R., Leone, G., DeGregori, J., and Nevins, J.R. (1999). Ras enhances Myc protein stability. Molecular Cell. 3:169-179. 24. Leone, G., DeGregori, J., Jakoi, L., Cook, J.G., and Nevins, J.R. (1999). Collaborative role of E2F transcriptional activity and G1 cyclin-dependent kinase activity in the induction of S phase. Proc. Natl. Acad. Sci. USA. 96:6626-6631. 25. Smith, DS., Leone, G., DeGregori, J., Ahmed, MN., Qumsiyeh, MB., Nevins, JR. (2000). Induction of DNA replication in adult rat neurons by deregulation of the retinoblastoma/E2F G1 cell cycle pathway. Cell Grow. & Diff. 11:625-633 26. Leone, G., Nuckolls, F., Ishida, S., Adams, M., Sears, R., Jakoi, L., Miron, A., Nevins, J.R. (2000) Identification of a novel E2F3 product suggests a mechanism for determining specificity of repression by Rb proteins. Mol. Cell. Biol. 20:10, 3626-3632 27. Adams,M.R., Sears, R., Nuckolls, F., Leone, G., and Nevins, J.R. (2000) Complex transcriptional regulatory mechanisms control expression of the E2F3 locus. Mol.Cell. Biol. 20:10 3633-3639. 28. Leone G., Sears R., Huang E., Rempel R., Nuckols F., Park C., Giangrande P., Wu L., Saavedra H.I., Field S.J., Thompson M.A., Yang H., Fujiwara Y., Greenberg M.E., Orkin S., Smith C., and Nevins J.R. (2001). Myc requires distinct E2F activities to induce S phase and apoptosis. Molecular Cell. 8: 105-113. 29. Weng LP, Gimm O, Kum JB, Smith WM, Zhou XP, Wynford-Thomas D, Leone G, Eng C. (2001). Transient ectopic expression of PTEN in thyroid cancer cell lines induces cell cycle arrest and cell type-dependent cell death. Hum Mol Genet. 10:3, 251-258 30. Tanner S.M., Austin J.L., Leone G., Rush L.J., Plass C., Heinonen K., Mrozek K., Sill H., Knuutila S., Kolitz J.E., Archer K.J., Caligiuri M.A., Bloomfield C.D., de la Chapelle A. (2001). BAALC, the human member of a novel mammalian neuroectoderm gene lineage, is implicated in hematopoiesis and acute leukemia. Proc.Natl.Acad. Sci.USA. 98:24 13901-13906. 31. Wu L., Timmers C., Baidehi M., Saavedra H.I., Sang L., Chong G.T., Nuckolls F., Giangrande P., Wright F.A., Field S.J., Greenberg M.E., Orkin S., Nevins J.R., Robinson M.L., and Leone G. (2001). The E2F1-3 transcription factors are essential for cellular proliferation. Nature. 414:457-462. 32. Ishida S., Huang E., Zuzan H., Spang R., Leone G., West M., Nevins, J.R. (2001). Role for E2F in control of both DNA replication and mitotic functions as revealed from DNA micro array analysis. Mol. Cell. Biol, 21: 14, 4684-4699. 33. Zhao Y., Gilmore R., Leone G., Coffey M.C., Weber B., Lee P.W.K. 2001. Hsp90 phosphorylation is linked to its chaperoning function. J. Biol. Chem. 276:35 32822-32827. 34. Lan Z., Sever-Chroneos Z., Strobeck M.W., Park C., Baskaran R., Edelmann W., Leone G. and Knudsen E S. (2002). DNA damage invokes mismatch-repair-dependent cyclin D1 attenuation and retinoblastoma signaling pathways to inhibit cdk2. J. Biol. Chem. 277:10 8372-8381. 35. Cook J.G., Park C., Burke T.W., Leone G., DeGregori J., Engel A., and Nevins J.R. (2002). Analysis of Cdc6 function in the assembly of mammalian prereplication complexes. Proc. Natl. Acad. Sci. USA, 99:3 1347-1352. 36. Saavedra H.I., Wu L., de Bruin A., Timmers C., Rosol T.R., Weinstein M., Robinson M.L, and Leone G. (2002). Specificity of E2F1, E2F2 and E2F3 in mediating phenotypes induced by loss of Rb. Cell Growth & Differentiation (13:5 215-225). Cover of Journal. 37. de la Puente A, Hall J., Wu YZ., Leone G., Peters J., Yoon BJ., Soloway P., Plass C. 2002. Structural characterization of Rasgrf1 and a novel linked imprinted locus. Gene 291: 287-297. 38. Toribio RE., Kohn CW., Leone G., Capen CC., and Rosol TJ. 2003. Molecular cloning and expression of equine calcitonin, calcitonin gene-related peptide-I, and calcitonin gene-related peptide-II. Molecular and Cellular Endocrinology Jan 31;199(1-2):119-28. 39. Wu L., de Bruin A., Saavedra HI., Trimboli A., Yang Y., Opavska J., Wilson P., Starovic M., Ostrowski MC., Cross JC., Weinstein M., Rosol TJ., Robinson ML., and Leone G. 2003. Extraembryonic function of Rb is essential for embryonic development and viability. Nature 421: 942-947. (N&V; 421: 903-004) 40. Saavedra HI., Maiti B., Timmers C., Altura R., Fukasawa K., and Leone G.. 2003. Inactivation of E2F3 results in premature centriole separation and centrosome amplification. Cancer Cell 3: 333-346 (Cover). 41. de Bruin A., Wu L., Saavedra H.I., Wilson P., Yang Y., Weinstein M., Rosol T.J., Robinsom M.L., Leone G. 2003. Rb function in extraembryonic lineages is critical for the control of apoptosis in the central nervous system of Rb-deficient mice. Proc. Natl. Acad. Sci..USA, 100:11, 6546-6551. 42. de Bruin A, Maiti B, Jakoi L, Timmers C, and Leone G. 2003. Identification and Characterization of E2F7, a Novel Mammalian E2F Family Member Capable of Blocking Cellular Proliferation. J. Biol. Chem. 278:43, 42041-42049. 43. Cheng S., Hsia Y.C., Leone G., and Liou H-C. 2003. Cyclin E and Bcl-XL cooperatively induce cell cycle progression in c-Rel-/- B cells. Oncogene 22,8472-8486. 44. Zhang J, Gray J, Wu L, Leone G., Rowan S, Cepko CL, Zhu X, Craft CM, Dyer MA. 2004. Rb regulates proliferation and rod photoreceptor development in the mouse retina. Nature Genetics 36:4 1-10. 45. Dai Z., Popkie AP., Zhu W., Timmers CD.,, Raval A., Tannehill-Gregg S., Morrison CD., Auer H., Kratzke RA., Niehans G., Amatschek S., Sommergruber W., Leone G., Rosol T., Otterson GA., Plass C. 2004. Bone morphogenetic protein 3B silencing in non-small-cell lung cancer. Oncogene 23, 3521-3529. 46.Jiang Y., Saavedra HI., Holloway MP., Leone G., Altura RA. 2004. Aberrant Regulation of Survivin by the Rb/E2F Family of Proteins. J. Biol. Chem. 279(39):40511-20. 47. Yu L., Liu C., Bennett K., Wu Y-Z., Dai Z., Vandeussen J., Opavsky R., Raval A., Trikha, P., Rodriguez B., Becknell B., Mao C., Lee S., Davuluri RV., Leone G., Van den Veyer IB., Caligiuri MA., Plass C. 2004. A NotI-EcoRV promoter library for studies of genetic and epigenetic alterations in mouse models of human malignancies. Genomics. 84(4):647-60. 48. Iavarone A., King ER., Dai X., Leone G., Stanley ER., Lasorella A. 2004. Retinoblastoma promotes definitive erythropoiesis by repressing Id2 in fetal liver macrophages. Nature 432: 1040-1045. 49. Chen Q, Liang D, Yang T, Leone G, Overbeek PA. 2004. Distinct capacities of individual E2Fs to induce cell cycle re-entry in postmitotic lens fiber cells of transgenic mice. Dev Neurosci. ;26(5-6):435-45. 50. Maiti B., Li J., de Bruin A., Gordon F., Timmers C, Opavsky R., Patil K., Tuttle J., Cleghorn W.,and Leone G. 2005. Cloning and Characterization of Mouse E2F8, a Novel Mammalian E2F Family Member Capable of Blocking Cellular Proliferation. J. Biol. Chem. 280, 18211-20. 51. Logan N., Graham A., Zhao X., Fisher R., Maiti B., Leone G., La Thangue N. 2005. E2F-8: an E2F family member with a similar organization of DNA binding domains to E2F-7. Oncogene 24: 5000-04. 52. Sharma N, Timmers C., Trikha P., Saavedra HI., Obery A., Opavsky R., and Leone G. 2006. Control of the p53-p21CIP1 Axis by E2f1, E2f2 and E2f3 is Essential for G1/S Progression and Cellular Transformation. J. Biol. Chem. 281, 36124-31. 53. Dorrance, A, Liu, S., Yuan, W., Becknell, B., Arnoczky, K., Guimond, M., Strout, M., Feng, L., Nakamura, T., Yu, L., Rush, L., Weinstein, M., Leone, G., Wu, L., Ferketich, A., Whitman, S., Marcucci, G., and Caligiuri, M., 2006. The Mll partial tandem duplication induces aberrant Hox expression in vivo via specific epigenetic alterations. J. Clin. Invest. 116:2707-16. 54. Mosaliganti R, Pan T, Sharp R, Ridgway R, Iyengar S, Gulacy A, Wenzel P, de Bruin A, Machiraju R, Huang K, Leone G, Saltz J. 2006. Registration and 3D visualization of large microscopy images, Proc. SPIE Ann. Med. Ima. Meet. 923-34. 55. Sharp R, Ridgway R, Mosalignati K, Irfanoglu O, Wenzel P, Machiraju R, Pan T, de Bruin A, Machuraju R, Leone G, Huang K, Saltz J. 2006. Examining Phenotype Differences in Mouse Placenta with Volume Rendering and Segmentation. Proc. IEEE/NLM Life Sc. Syst. & Appl. 70-71. 56. Timmers C., Opavsky R., Maiti B., Wu L., Wu J., Orringer D., Sharma N., Saavedra HI., Leone G. 2007. E2f1-3 control E2F-target expression and cellular proliferation via a p53-dependent negative feedback loop. Mol Cell Biol. 27:65-78. 57. Sharp R., Ridgway R., Mosaliganti K., Wenzel P., Pan T., de Bruin A., Machiraju R., Huang K., Leone G., Saltz J. 2007. Volume rendering phenotype differences in mouse placenta microscopy data. Comp. Sci and Eng. 9:38-47. 58. Wenzel P., Wu L., de Bruin A., Chong J-L., Chen, W-Y., Dureska G., Sites E., Pan T., Sharma A., Huang K., Ridgway R., Mosaliganti K., Sharp R., Machiraju R., Saltz J., Yamamoto H., Cross J., Robinson M., Leone, G. 2007 Rb is critical in a mammalian tissue stem cell population. Genes & Development 21:85-97. 59. Wenzel, P., Leone, G. 2007. Expression of Cre recombinase in early diploid trophoblast cells of the mouse placenta. Genesis 45:129-134. 60. Mosaliganti K, Janoos F, Sharp R, Ridgway R, Machiraju R, Huang K, Wenzel P, deBruin A, Leone G, Saltz J. 2007. Detection and visualization of surface-pockets to enable phenotyping studies. IEEE Trans. Medical Imaging 26:1283-1290. 61. Janoos F, Irfanoglu O, Mosaliganti K, Machiraju R, Huang K, Wenzel P, de Bruin A, Leone G. 2007. Multiple-resolution image segmentation using the 2-point correlation functions. Proc. IEEE Internat. Symp. Medical Imaging. 62. McClellan K., Ruzhynsky V., Douda D., Vanderluit J., Ferguson K., Chen D., Bremner R., Park D., Leone G., and Slack R. 2007. Unique requirement for Rb/E2F3 in neuronal migration: evidence for cell cycle-independent functions. Mol Cell Biol 27:4825-43. 63. Chen D., Opavsky R., Pacal M., Tanimoto N., Wenzel P., Seeliger M., Leone G., and Bremner R. 2007. Rb-mediated neuronal differentiation through cell cycle independent regulation of E2f3a. PLoS Biology 5:e179 1-16. 64. Opavsky R., Wang S-H., Trikha P., Raval A., Huang Y., Wu Y-A., Rodriguez B., Keller B., Liyanarachi S., Wei G., Davuluri R., Weinstein M., Felsher D., Ostrowski M.C., Leone G*, and Plass C*. 2007. CpG island methylation in cancer is driven by the genetic configuration of tumor cells. PLoS Genetics 3:1757-69. *corresponding authors 65. Opavsky R., Tsai S-Y., Guimond M., Arora A., Opavska J., Becknell B., Kauffman M., Walton N., Stephens J., Fernandez S., Muthusamy N., Felsher W., Porcu P., Caligiuri M., and Leone G. 2007. Specific tumor suppressor function for E2F2 in Myc-induced T cell lymphomagenesis. Proc. Natl. Acad. Sci..USA. 104:39, 15400-15405. 66. Saenz-Robles M., Markovics J.A., Chong J-L., Opavsky R., Whitehead R.H., Leone G., Pipas J.M. 2007. Intestinal hyperplasia induced by SV40 large tumor antigen requires E2F2. J. Virology 81:13191-9. 67. Trimboli A.J., Fukino K., de Bruin A., Wei G., Shen L., Tanner S.M., Rosol T.J., Eng C., Ostrowski M.C., and Leone G. 2008. In Vivo Visualization of Myc-induced Epithelial-Mesenchymal Transitions in Breast Cancer. Cancer Research 68(3) 937-945. 68. Li J., Ran C., Li E., Gordon F., Comstock G.,Siddiqui H., Cleghorn W., Chen H-Z., Kornacker K., Liu C-G., Pandit S., Khanizadeh M., Weinstein M., Leone G*., and de Bruin A. 2008. Synergistic function of E2F7and E2F8 is essential for cell survival and embryonic development. Devel Cell 14:62-75.. *corresponding author 69. Tsai S-Y., Opavsky R., Sharma N., Wu L., Naidu S., Nolan E., Ferias-Arias E., Timmers C., Opavska J., de Bruin A., Chong J-L., Trikha P., Stromberg P., Rosol J.R., and Leone, G. 2008. Mouse development with a single E2F activator. Nature 454:1137-41 70. Mosaliganti K, Sharp R., Ridgway R., Wenzel P., de Bruin A., Machiraju R., Leone G., and Saltz J. Categorical visualization using shape-based transfer functions for surface morphometry. (submitted) 71. Chong J-L., Tsai S-Y., Opavsky R., Wu L., Nair V., and Leone G. Loss of E2f3a but not E2f3b suppresses Rb-null embryonic phenotypes. (submitted) |
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