Affixin interacts with α-actinin and mediates integrin signaling for reorganization of F-actin induced by initial cell–substrate interaction

The linking of integrin to cytoskeleton is a critical event for an effective cell migration. Previously, we have reported that a novel integrin-linked kinase (ILK)–binding protein, affixin, is closely involved in the linkage between integrin and cytoskeleton in combination with ILK. In the present work, we demonstrated that the second calponin homology domain of affixin directly interacts with α-actinin in an ILK kinase activity–dependent manner, suggesting that integrin–ILK signaling evoked by substrate adhesion induces affixin–α-actinin interaction. The overexpression of a peptide corresponding to the α-actinin–binding site of affixin as well as the knockdown of endogenous affixin by small interference RNA resulted in the blockade of cell spreading. Time-lapse observation revealed that in both experiments cells were round with small peripheral blebs and failed to develop lamellipodia, suggesting that the ILK–affixin complex serves as an integrin-anchoring site for α-actinin and thereby mediates integrin signaling to α-actinin, which has been shown to play a critical role in actin polymerization at focal adhesions

A New Three-Way Translocation t(4;11;7)(q21;q23;q22) in a Mixed-Phenotype Acute Leukemia

A 68-year-old man was admitted to our hospital in September 2008 because of a left-sided chest pain. Bone marrow examination showed that 85.5% of leukemic cells were positive for myeloperoxidase (MPO) and were negative for esterase stain. Flow cytometric analysis (FCM) revealed the expression of CD19, CD79a, CD13, CD33, CD34, and HLA-DR on the blasts. Cytogenetic analysis of bone marrow cells using the G-banding technique demonstrated 47, XY, +X, t(4;11;7)(q21;q23;q22) in five of the 20 analyzed cells. The patient was diagnosed as having mixed biphenotypic acute leukemia according to the European Group for Immunologic Classification of Leukemia criteria. Mixed-phenotype acute leukemia is a rare, difficult to diagnose entity. Whether patients with mixed-phenotype acute leukemia should be treated with regimens designed for acute myeloid leukemia, acute lymphoblastic leukemia, or both remains unclear