Investigation of the Role of Shp2 Phosphatase Domains in Oncogenic KIT Receptor Mediated Transformation

Indianapolis, IN

Activating mutations of KIT (KITD816V), encoding the receptor for stem cell factor, are found in greater than 90% of patients with systemic mastocytosis. Previous studies have demonstrated that Shp2 phosphatase is essential for oncogenic KIT induced growth in vitro and with myeloproliferative neoplasms in vivo. Shp2 has several functional domains including N-SH2, C-SH2, phosphatase (PTP), and proline-rich domains. To evaluate the role of Shp2 domains in regulating KITD814V induced transformation, we cloned specific Shp2 domain mutants into MIEG3 retroviral vector in tandem with human CD4. Murine derived 32D myeloid cells were retrovirally co-transduced with KITD814V expressing GFP, and each of the Shp2 mutants expressing human CD4. In identifying the role of these domains in KITD814V induced proliferation and survival, cells lines were subjected to thymidine proliferation, apoptosis, and cell cycle assays. Our data suggests that the N-terminal SH2 domain plays an important role in growth and survival of oncogenic KITD814V bearing cells with a marked increased in apoptosis, and a decrease in cell proliferation. However, further experiments are warranted to conclude the importance of these domains with respect to oncogenic KIT mediated transformation.