Pleiotropic Functions of HTLV-1 Tax Contribute to Cellular Transformation

Abstract

Human T cell leukemia virus type-1 (HTLV-1) is the only retrovirus known to be the etiologic agent of a human cancer, adult T-cell leukemia/lymphoma (ATLL), a highly aggressive cancer of mature T cells. Epidemiological reports suggest that 10 to 20 million people throughout the world are infected with HTLV-1, which is endemic in parts of sub-Saharan Africa, the Caribbean, Japan, and South America [1]. HTLV-1 encodes a regulatory protein, Tax, which is essential for virus replication and plays a significant role in the oncogenic potential of HTLV-1. This chapter will summarize the effects of Tax on cellular processes including transcription, cell cycle checkpoints, and DNA repair, and will discuss how these activities may contribute to its transforming potential. 2.