Dystroglycan Depletion Impairs Actin-Dependent Functions of Differentiated Kasumi-1 Cells

Dystroglycan has recently been characterised in blood tissue cells, as part of the dystrophin glycoprotein complex involved in the differentiation process of neutrophils. In the present study we have investigated the role of dystroglycan in the human promyelocytic leukemic cell line Kasumi-1 differentiated to macrophage-like cells. We characterised the pattern expression and subcellular distribution of dystroglycans in non-differentiated and differentiated Kasumi-1 cells. Our results demonstrated by WB and flow cytometer assays that during the differentiation process to macrophages, dystroglycans were down-regulated; these results were confirmed with qRT-PCR assays. Additionally, depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated Kasumi-1 cells, including morphology, migration and phagocytic activities although secretion of IL-1β and expression of markers of differentiation are not altered. Our findings strongly implicate dystroglycan as a key membrane adhesion protein involved in actin-based structures during the differentiation process in Kasumi-1 cells.