Tian Xu, Ph.D.

Research

Our laboratory is interested in utilizing model organisms to understand cancer biology and developmental mechanisms. In particular, we are developing and using new genetic approaches to identify genes that are involved in tumor growth and metastasis, and are exploring the developmental and biochemical functions of these genes. Our work on tumor growth have shown that tumor suppressors such as TSC, PTEN, and LATS regulate tissue and organism size during development and propose that deregulation of size-control mechanisms is essential for tumorigenesis. We have showed that TSC and PTEN genes function in the PI3K/Akt pathway and reduction of S6K activity levitates TSC defects. These findings have helped to define one of the major cancer pathways in humans and have lead to clinical trials for TSC and LAM diseases. One of our long term goals is to develop methodologies in mammals for interrogating the genome by forward genetics. We have successfully adapted the piggyBac transposon for transgenesis and insertional mutagenesis in mammals. This has led to the development of a highly efficient single transposon mutagenesis strategy and to the near-production of the first set of genome-wide insertional mutants in mice, which will provide an unprecedented opportunity for deciphering mammalian biology and disease.