tailieunhanh - Methods in Molecular BiologyTM VOLUME 218 Cancer Cell Signaling Methods and Protocols

Loss of tumor suppressors contributes to numerous cancer types. Many, but not all, proteins encoded by tumor suppressor genes have antiproliferative activity and halt cell-cycle progression. In this chapter, we present three methods that have been utilized to monitor the antimitogenic action exerted by tumor suppressors. Tumor suppressor function can be demonstrated by colony formation assays and acquisition of the flat-cell phenotype. | Methods in Molecular Biology VOLUME 218 Cancer Cell Signaling Methods and Protocols Edited by David M. Terrian HUMANA PRESS 1 Functional Analysis of the Antimitogenic Activity of Tumor Suppressors Erik S. Knudsen and Steven P. Angus Abstract Loss of tumor suppressors contributes to numerous cancer types. Many but not all proteins encoded by tumor suppressor genes have antiproliferative activity and halt cell-cycle progression. In this chapter we present three methods that have been utilized to monitor the antimitogenic action exerted by tumor suppressors. Tumor suppressor function can be demonstrated by colony formation assays and acquisition of the flat-cell phenotype. Because of the antiproliferative action of these agents we also present two transient assays that monitor the effect of tumor suppressors on cell-cycle progression. One is based on BrdU incorporation . DNA replication and the other on flow cytometry. Together this triad of techniques is sufficient to determine the action of tumor suppressors and other antiproliferative agents. Key Words Tumor suppressor green fluorescent protein bromo-deoxy-uridine retinoblastoma cell cycle cyclin flow cytometry mitogen fluorescence microscopy. 1. Introduction The discovery of tumor suppressor genes whose loss predisposes to tumor development has revolutionized the molecular analysis of cancer 1-3 . By definition tumor suppressor genes are genetically linked to a cancer. For example the retinoblastoma RB tumor suppressor was first identified as a gene that was specifically lost in familial RB 4-6 . The majority of tumor suppressors From Methods in Molecular Biology vol. 218 Cancer Cell Signaling Methods and Protocols Edited by D. M. Terrian Humana Press Inc. Totowa NJ 3 4 Knudsen and Angus has been identified based on linkage analysis and subsequent epidemiological studies however initial understanding of their mode of action was relatively limited. As the number of tumor suppressors has increased understanding .