Vijay Yajnik, MD, PhD

Assistant Professor of Medicine
Harvard Medical School

Research Interests:

We are studying the molecular basis of cancer progression to metastasis. Our approach involves understanding the signaling pathway orchestrated by the guanine exchange factor (GEF) DOCK4 mediating cytoskeletal re-organization during cell adhesion and migration. DOCK4 was identified as a homozygous deletion in a mouse osteosarcoma cell line driven by the loss of tumor suppressors NF2 and p53. DOCK4 is targeted by mutations in several established human cancer cell lines and the biological consequences of these mutations are being studied. In addition, both in vivo and in vitro models of GI cancers are also being pursued in the laboratory.

Recent Publications:

1. Yajnik V, Paulding C, Sordella R, McClatchey A, Saito M, Wahrer D, Bell D, Lake R, van den Huevel S, Settleman J, Haber D. DOCK4, a GTPase activator, is disrupted during tumorigenesis. Cell 2003;112: 673-684.
   
   
2. Thayer SP, Pasca di Margliano M, Heiser PW, Roberts DJ, Nielse CM, Lauwers GY, Qi YP, Gysin S, Fernandez-del Castillo C, Yajnik V, Anoniu B, McMahan M, Warshaw AL, Hebrok M. Hedgehog an early and late mediator of pancreatic tumorigensis. Nature 2003; 425:851-6.
   
   
3. Reynolds PA, Smolen GA, Palmer RE, Sgroi D, Yajnik V, Gerald WL, Haber DA. Identification of a DNA-binding site and transcriptional target for the EWS-WT1(+KTS) oncoprotein. Genes Dev. 2003; 17:2094-107.
   
   
4. V. Yajnik, P. Blaikie, P. Bork, B. Margolis. Identification of residues within the Shc PTB/PI domain crucial for phosphopeptide interaction. J. Biol. Chem, 1996;271: 1813-1816.
   
   
5. S. Isakoff, Y. Yu, Y. Su, P. Blaikie, V. Yajnik, K. Weidner, M. Sachs, B. Margolis and E. Skolnik . The Shc PTB/PI domain is required for Shc tyrosine phosphorylation by the insulin receptor (IR) and recognizes an NPXY motif on the IR that is distinct from IRS-1 in vivo. J. Biol. Chem.,1996; 271: 2410-2416.
   
   
6. J. Ooi, V. Yajnik, D. Immanuel, M. Gordon, J.J. Moskow, A.M. Buchberg, and B. Margolis. The cloning of Grb 10 reveals a new family of SH2 domain proteins. Oncogene,1995; 10: 1621-1630.
   
   
7. P. Blaikie, D. Immanuel, J. Wu, N. Li, V. Yajnik, and B. Margolis (1994) A region in Shc distinct from the SH2 domain can bind tyrosine-phosphorylated growth factor receptors. J. Biol. Chem., 1994; 269: 32031-32034.
   
   
8. D. Stein, J. Wu, S.A.W. Fuqua, C. Roonprapunt, V. Yajnik, P. D'Eustachio, J. J. Moskow, A.M. Buchberg, C. K. Osborne and B. Margolis. The SH2 domain protein GRB-7 is coamplified, overexpressed and in a tight complex with HER2 in breast cancer. EMBO J., 1993;13:1331-1340.